[gdbserver] Remove unused max_jump_pad_size
[deliverable/binutils-gdb.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright (C) 2009-2015 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
7 // bfd/elf32-arm.c.
8
9 // This file is part of gold.
10
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 3 of the License, or
14 // (at your option) any later version.
15
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 // GNU General Public License for more details.
20
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 // MA 02110-1301, USA.
25
26 #include "gold.h"
27
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
36
37 #include "elfcpp.h"
38 #include "parameters.h"
39 #include "reloc.h"
40 #include "arm.h"
41 #include "object.h"
42 #include "symtab.h"
43 #include "layout.h"
44 #include "output.h"
45 #include "copy-relocs.h"
46 #include "target.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
49 #include "tls.h"
50 #include "defstd.h"
51 #include "gc.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
54 #include "nacl.h"
55
56 namespace
57 {
58
59 using namespace gold;
60
61 template<bool big_endian>
62 class Output_data_plt_arm;
63
64 template<bool big_endian>
65 class Output_data_plt_arm_standard;
66
67 template<bool big_endian>
68 class Stub_table;
69
70 template<bool big_endian>
71 class Arm_input_section;
72
73 class Arm_exidx_cantunwind;
74
75 class Arm_exidx_merged_section;
76
77 class Arm_exidx_fixup;
78
79 template<bool big_endian>
80 class Arm_output_section;
81
82 class Arm_exidx_input_section;
83
84 template<bool big_endian>
85 class Arm_relobj;
86
87 template<bool big_endian>
88 class Arm_relocate_functions;
89
90 template<bool big_endian>
91 class Arm_output_data_got;
92
93 template<bool big_endian>
94 class Target_arm;
95
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
98
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
106
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
109
110 // The arm target class.
111 //
112 // This is a very simple port of gold for ARM-EABI. It is intended for
113 // supporting Android only for the time being.
114 //
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 // Thumb-2 and BE8.
119 // There are probably a lot more.
120
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops. If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked. The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
128 //
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only. That
131 // way we can avoid initialization when the linker starts.
132
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
134
135 // Instruction template class. This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
137
138 class Insn_template
139 {
140 public:
141 // Types of instruction templates.
142 enum Type
143 {
144 THUMB16_TYPE = 1,
145 // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146 // templates with class-specific semantics. Currently this is used
147 // only by the Cortex_a8_stub class for handling condition codes in
148 // conditional branches.
149 THUMB16_SPECIAL_TYPE,
150 THUMB32_TYPE,
151 ARM_TYPE,
152 DATA_TYPE
153 };
154
155 // Factory methods to create instruction templates in different formats.
156
157 static const Insn_template
158 thumb16_insn(uint32_t data)
159 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
160
161 // A Thumb conditional branch, in which the proper condition is inserted
162 // when we build the stub.
163 static const Insn_template
164 thumb16_bcond_insn(uint32_t data)
165 { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
166
167 static const Insn_template
168 thumb32_insn(uint32_t data)
169 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
170
171 static const Insn_template
172 thumb32_b_insn(uint32_t data, int reloc_addend)
173 {
174 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175 reloc_addend);
176 }
177
178 static const Insn_template
179 arm_insn(uint32_t data)
180 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
181
182 static const Insn_template
183 arm_rel_insn(unsigned data, int reloc_addend)
184 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
185
186 static const Insn_template
187 data_word(unsigned data, unsigned int r_type, int reloc_addend)
188 { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
189
190 // Accessors. This class is used for read-only objects so no modifiers
191 // are provided.
192
193 uint32_t
194 data() const
195 { return this->data_; }
196
197 // Return the instruction sequence type of this.
198 Type
199 type() const
200 { return this->type_; }
201
202 // Return the ARM relocation type of this.
203 unsigned int
204 r_type() const
205 { return this->r_type_; }
206
207 int32_t
208 reloc_addend() const
209 { return this->reloc_addend_; }
210
211 // Return size of instruction template in bytes.
212 size_t
213 size() const;
214
215 // Return byte-alignment of instruction template.
216 unsigned
217 alignment() const;
218
219 private:
220 // We make the constructor private to ensure that only the factory
221 // methods are used.
222 inline
223 Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224 : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
225 { }
226
227 // Instruction specific data. This is used to store information like
228 // some of the instruction bits.
229 uint32_t data_;
230 // Instruction template type.
231 Type type_;
232 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233 unsigned int r_type_;
234 // Relocation addend.
235 int32_t reloc_addend_;
236 };
237
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
240
241 #define DEF_STUBS \
242 DEF_STUB(long_branch_any_any) \
243 DEF_STUB(long_branch_v4t_arm_thumb) \
244 DEF_STUB(long_branch_thumb_only) \
245 DEF_STUB(long_branch_v4t_thumb_thumb) \
246 DEF_STUB(long_branch_v4t_thumb_arm) \
247 DEF_STUB(short_branch_v4t_thumb_arm) \
248 DEF_STUB(long_branch_any_arm_pic) \
249 DEF_STUB(long_branch_any_thumb_pic) \
250 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253 DEF_STUB(long_branch_thumb_only_pic) \
254 DEF_STUB(a8_veneer_b_cond) \
255 DEF_STUB(a8_veneer_b) \
256 DEF_STUB(a8_veneer_bl) \
257 DEF_STUB(a8_veneer_blx) \
258 DEF_STUB(v4_veneer_bx)
259
260 // Stub types.
261
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
264 {
265 arm_stub_none,
266 DEF_STUBS
267
268 // First reloc stub type.
269 arm_stub_reloc_first = arm_stub_long_branch_any_any,
270 // Last reloc stub type.
271 arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
272
273 // First Cortex-A8 stub type.
274 arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275 // Last Cortex-A8 stub type.
276 arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
277
278 // Last stub type.
279 arm_stub_type_last = arm_stub_v4_veneer_bx
280 } Stub_type;
281 #undef DEF_STUB
282
283 // Stub template class. Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
286
287 class Stub_template
288 {
289 public:
290 Stub_template(Stub_type, const Insn_template*, size_t);
291
292 ~Stub_template()
293 { }
294
295 // Return stub type.
296 Stub_type
297 type() const
298 { return this->type_; }
299
300 // Return an array of instruction templates.
301 const Insn_template*
302 insns() const
303 { return this->insns_; }
304
305 // Return size of template in number of instructions.
306 size_t
307 insn_count() const
308 { return this->insn_count_; }
309
310 // Return size of template in bytes.
311 size_t
312 size() const
313 { return this->size_; }
314
315 // Return alignment of the stub template.
316 unsigned
317 alignment() const
318 { return this->alignment_; }
319
320 // Return whether entry point is in thumb mode.
321 bool
322 entry_in_thumb_mode() const
323 { return this->entry_in_thumb_mode_; }
324
325 // Return number of relocations in this template.
326 size_t
327 reloc_count() const
328 { return this->relocs_.size(); }
329
330 // Return index of the I-th instruction with relocation.
331 size_t
332 reloc_insn_index(size_t i) const
333 {
334 gold_assert(i < this->relocs_.size());
335 return this->relocs_[i].first;
336 }
337
338 // Return the offset of the I-th instruction with relocation from the
339 // beginning of the stub.
340 section_size_type
341 reloc_offset(size_t i) const
342 {
343 gold_assert(i < this->relocs_.size());
344 return this->relocs_[i].second;
345 }
346
347 private:
348 // This contains information about an instruction template with a relocation
349 // and its offset from start of stub.
350 typedef std::pair<size_t, section_size_type> Reloc;
351
352 // A Stub_template may not be copied. We want to share templates as much
353 // as possible.
354 Stub_template(const Stub_template&);
355 Stub_template& operator=(const Stub_template&);
356
357 // Stub type.
358 Stub_type type_;
359 // Points to an array of Insn_templates.
360 const Insn_template* insns_;
361 // Number of Insn_templates in insns_[].
362 size_t insn_count_;
363 // Size of templated instructions in bytes.
364 size_t size_;
365 // Alignment of templated instructions.
366 unsigned alignment_;
367 // Flag to indicate if entry is in thumb mode.
368 bool entry_in_thumb_mode_;
369 // A table of reloc instruction indices and offsets. We can find these by
370 // looking at the instruction templates but we pre-compute and then stash
371 // them here for speed.
372 std::vector<Reloc> relocs_;
373 };
374
375 //
376 // A class for code stubs. This is a base class for different type of
377 // stubs used in the ARM target.
378 //
379
380 class Stub
381 {
382 private:
383 static const section_offset_type invalid_offset =
384 static_cast<section_offset_type>(-1);
385
386 public:
387 Stub(const Stub_template* stub_template)
388 : stub_template_(stub_template), offset_(invalid_offset)
389 { }
390
391 virtual
392 ~Stub()
393 { }
394
395 // Return the stub template.
396 const Stub_template*
397 stub_template() const
398 { return this->stub_template_; }
399
400 // Return offset of code stub from beginning of its containing stub table.
401 section_offset_type
402 offset() const
403 {
404 gold_assert(this->offset_ != invalid_offset);
405 return this->offset_;
406 }
407
408 // Set offset of code stub from beginning of its containing stub table.
409 void
410 set_offset(section_offset_type offset)
411 { this->offset_ = offset; }
412
413 // Return the relocation target address of the i-th relocation in the
414 // stub. This must be defined in a child class.
415 Arm_address
416 reloc_target(size_t i)
417 { return this->do_reloc_target(i); }
418
419 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
420 void
421 write(unsigned char* view, section_size_type view_size, bool big_endian)
422 { this->do_write(view, view_size, big_endian); }
423
424 // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425 // for the i-th instruction.
426 uint16_t
427 thumb16_special(size_t i)
428 { return this->do_thumb16_special(i); }
429
430 protected:
431 // This must be defined in the child class.
432 virtual Arm_address
433 do_reloc_target(size_t) = 0;
434
435 // This may be overridden in the child class.
436 virtual void
437 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
438 {
439 if (big_endian)
440 this->do_fixed_endian_write<true>(view, view_size);
441 else
442 this->do_fixed_endian_write<false>(view, view_size);
443 }
444
445 // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446 // instruction template.
447 virtual uint16_t
448 do_thumb16_special(size_t)
449 { gold_unreachable(); }
450
451 private:
452 // A template to implement do_write.
453 template<bool big_endian>
454 void inline
455 do_fixed_endian_write(unsigned char*, section_size_type);
456
457 // Its template.
458 const Stub_template* stub_template_;
459 // Offset within the section of containing this stub.
460 section_offset_type offset_;
461 };
462
463 // Reloc stub class. These are stubs we use to fix up relocation because
464 // of limited branch ranges.
465
466 class Reloc_stub : public Stub
467 {
468 public:
469 static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470 // We assume we never jump to this address.
471 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
472
473 // Return destination address.
474 Arm_address
475 destination_address() const
476 {
477 gold_assert(this->destination_address_ != this->invalid_address);
478 return this->destination_address_;
479 }
480
481 // Set destination address.
482 void
483 set_destination_address(Arm_address address)
484 {
485 gold_assert(address != this->invalid_address);
486 this->destination_address_ = address;
487 }
488
489 // Reset destination address.
490 void
491 reset_destination_address()
492 { this->destination_address_ = this->invalid_address; }
493
494 // Determine stub type for a branch of a relocation of R_TYPE going
495 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
496 // the branch target is a thumb instruction. TARGET is used for look
497 // up ARM-specific linker settings.
498 static Stub_type
499 stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500 Arm_address branch_target, bool target_is_thumb);
501
502 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
503 // and an addend. Since we treat global and local symbol differently, we
504 // use a Symbol object for a global symbol and a object-index pair for
505 // a local symbol.
506 class Key
507 {
508 public:
509 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
511 // and R_SYM must not be invalid_index.
512 Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513 unsigned int r_sym, int32_t addend)
514 : stub_type_(stub_type), addend_(addend)
515 {
516 if (symbol != NULL)
517 {
518 this->r_sym_ = Reloc_stub::invalid_index;
519 this->u_.symbol = symbol;
520 }
521 else
522 {
523 gold_assert(relobj != NULL && r_sym != invalid_index);
524 this->r_sym_ = r_sym;
525 this->u_.relobj = relobj;
526 }
527 }
528
529 ~Key()
530 { }
531
532 // Accessors: Keys are meant to be read-only object so no modifiers are
533 // provided.
534
535 // Return stub type.
536 Stub_type
537 stub_type() const
538 { return this->stub_type_; }
539
540 // Return the local symbol index or invalid_index.
541 unsigned int
542 r_sym() const
543 { return this->r_sym_; }
544
545 // Return the symbol if there is one.
546 const Symbol*
547 symbol() const
548 { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
549
550 // Return the relobj if there is one.
551 const Relobj*
552 relobj() const
553 { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
554
555 // Whether this equals to another key k.
556 bool
557 eq(const Key& k) const
558 {
559 return ((this->stub_type_ == k.stub_type_)
560 && (this->r_sym_ == k.r_sym_)
561 && ((this->r_sym_ != Reloc_stub::invalid_index)
562 ? (this->u_.relobj == k.u_.relobj)
563 : (this->u_.symbol == k.u_.symbol))
564 && (this->addend_ == k.addend_));
565 }
566
567 // Return a hash value.
568 size_t
569 hash_value() const
570 {
571 return (this->stub_type_
572 ^ this->r_sym_
573 ^ gold::string_hash<char>(
574 (this->r_sym_ != Reloc_stub::invalid_index)
575 ? this->u_.relobj->name().c_str()
576 : this->u_.symbol->name())
577 ^ this->addend_);
578 }
579
580 // Functors for STL associative containers.
581 struct hash
582 {
583 size_t
584 operator()(const Key& k) const
585 { return k.hash_value(); }
586 };
587
588 struct equal_to
589 {
590 bool
591 operator()(const Key& k1, const Key& k2) const
592 { return k1.eq(k2); }
593 };
594
595 // Name of key. This is mainly for debugging.
596 std::string
597 name() const;
598
599 private:
600 // Stub type.
601 Stub_type stub_type_;
602 // If this is a local symbol, this is the index in the defining object.
603 // Otherwise, it is invalid_index for a global symbol.
604 unsigned int r_sym_;
605 // If r_sym_ is an invalid index, this points to a global symbol.
606 // Otherwise, it points to a relobj. We used the unsized and target
607 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608 // Arm_relobj, in order to avoid making the stub class a template
609 // as most of the stub machinery is endianness-neutral. However, it
610 // may require a bit of casting done by users of this class.
611 union
612 {
613 const Symbol* symbol;
614 const Relobj* relobj;
615 } u_;
616 // Addend associated with a reloc.
617 int32_t addend_;
618 };
619
620 protected:
621 // Reloc_stubs are created via a stub factory. So these are protected.
622 Reloc_stub(const Stub_template* stub_template)
623 : Stub(stub_template), destination_address_(invalid_address)
624 { }
625
626 ~Reloc_stub()
627 { }
628
629 friend class Stub_factory;
630
631 // Return the relocation target address of the i-th relocation in the
632 // stub.
633 Arm_address
634 do_reloc_target(size_t i)
635 {
636 // All reloc stub have only one relocation.
637 gold_assert(i == 0);
638 return this->destination_address_;
639 }
640
641 private:
642 // Address of destination.
643 Arm_address destination_address_;
644 };
645
646 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
648 //
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 // branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 // branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
654 //
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least. We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch. The
658 // condition code is used in a special instruction template. We also want
659 // to identify input sections needing Cortex-A8 workaround quickly. We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up. The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
663 //
664
665 class Cortex_a8_stub : public Stub
666 {
667 public:
668 ~Cortex_a8_stub()
669 { }
670
671 // Return the object of the code section containing the branch being fixed
672 // up.
673 Relobj*
674 relobj() const
675 { return this->relobj_; }
676
677 // Return the section index of the code section containing the branch being
678 // fixed up.
679 unsigned int
680 shndx() const
681 { return this->shndx_; }
682
683 // Return the source address of stub. This is the address of the original
684 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
685 // instruction.
686 Arm_address
687 source_address() const
688 { return this->source_address_; }
689
690 // Return the destination address of the stub. This is the branch taken
691 // address of the original branch instruction. LSB is 1 if it is a THUMB
692 // instruction address.
693 Arm_address
694 destination_address() const
695 { return this->destination_address_; }
696
697 // Return the instruction being fixed up.
698 uint32_t
699 original_insn() const
700 { return this->original_insn_; }
701
702 protected:
703 // Cortex_a8_stubs are created via a stub factory. So these are protected.
704 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705 unsigned int shndx, Arm_address source_address,
706 Arm_address destination_address, uint32_t original_insn)
707 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708 source_address_(source_address | 1U),
709 destination_address_(destination_address),
710 original_insn_(original_insn)
711 { }
712
713 friend class Stub_factory;
714
715 // Return the relocation target address of the i-th relocation in the
716 // stub.
717 Arm_address
718 do_reloc_target(size_t i)
719 {
720 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
721 {
722 // The conditional branch veneer has two relocations.
723 gold_assert(i < 2);
724 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
725 }
726 else
727 {
728 // All other Cortex-A8 stubs have only one relocation.
729 gold_assert(i == 0);
730 return this->destination_address_;
731 }
732 }
733
734 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735 uint16_t
736 do_thumb16_special(size_t);
737
738 private:
739 // Object of the code section containing the branch being fixed up.
740 Relobj* relobj_;
741 // Section index of the code section containing the branch begin fixed up.
742 unsigned int shndx_;
743 // Source address of original branch.
744 Arm_address source_address_;
745 // Destination address of the original branch.
746 Arm_address destination_address_;
747 // Original branch instruction. This is needed for copying the condition
748 // code from a condition branch to its stub.
749 uint32_t original_insn_;
750 };
751
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
754 {
755 public:
756 ~Arm_v4bx_stub()
757 { }
758
759 // Return the associated register.
760 uint32_t
761 reg() const
762 { return this->reg_; }
763
764 protected:
765 // Arm V4BX stubs are created via a stub factory. So these are protected.
766 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767 : Stub(stub_template), reg_(reg)
768 { }
769
770 friend class Stub_factory;
771
772 // Return the relocation target address of the i-th relocation in the
773 // stub.
774 Arm_address
775 do_reloc_target(size_t)
776 { gold_unreachable(); }
777
778 // This may be overridden in the child class.
779 virtual void
780 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
781 {
782 if (big_endian)
783 this->do_fixed_endian_v4bx_write<true>(view, view_size);
784 else
785 this->do_fixed_endian_v4bx_write<false>(view, view_size);
786 }
787
788 private:
789 // A template to implement do_write.
790 template<bool big_endian>
791 void inline
792 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
793 {
794 const Insn_template* insns = this->stub_template()->insns();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[0].data()
797 + (this->reg_ << 16)));
798 view += insns[0].size();
799 elfcpp::Swap<32, big_endian>::writeval(view,
800 (insns[1].data() + this->reg_));
801 view += insns[1].size();
802 elfcpp::Swap<32, big_endian>::writeval(view,
803 (insns[2].data() + this->reg_));
804 }
805
806 // A register index (r0-r14), which is associated with the stub.
807 uint32_t reg_;
808 };
809
810 // Stub factory class.
811
812 class Stub_factory
813 {
814 public:
815 // Return the unique instance of this class.
816 static const Stub_factory&
817 get_instance()
818 {
819 static Stub_factory singleton;
820 return singleton;
821 }
822
823 // Make a relocation stub.
824 Reloc_stub*
825 make_reloc_stub(Stub_type stub_type) const
826 {
827 gold_assert(stub_type >= arm_stub_reloc_first
828 && stub_type <= arm_stub_reloc_last);
829 return new Reloc_stub(this->stub_templates_[stub_type]);
830 }
831
832 // Make a Cortex-A8 stub.
833 Cortex_a8_stub*
834 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835 Arm_address source, Arm_address destination,
836 uint32_t original_insn) const
837 {
838 gold_assert(stub_type >= arm_stub_cortex_a8_first
839 && stub_type <= arm_stub_cortex_a8_last);
840 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841 source, destination, original_insn);
842 }
843
844 // Make an ARM V4BX relocation stub.
845 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846 Arm_v4bx_stub*
847 make_arm_v4bx_stub(uint32_t reg) const
848 {
849 gold_assert(reg < 0xf);
850 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851 reg);
852 }
853
854 private:
855 // Constructor and destructor are protected since we only return a single
856 // instance created in Stub_factory::get_instance().
857
858 Stub_factory();
859
860 // A Stub_factory may not be copied since it is a singleton.
861 Stub_factory(const Stub_factory&);
862 Stub_factory& operator=(Stub_factory&);
863
864 // Stub templates. These are initialized in the constructor.
865 const Stub_template* stub_templates_[arm_stub_type_last+1];
866 };
867
868 // A class to hold stubs for the ARM target.
869
870 template<bool big_endian>
871 class Stub_table : public Output_data
872 {
873 public:
874 Stub_table(Arm_input_section<big_endian>* owner)
875 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877 prev_data_size_(0), prev_addralign_(1)
878 { }
879
880 ~Stub_table()
881 { }
882
883 // Owner of this stub table.
884 Arm_input_section<big_endian>*
885 owner() const
886 { return this->owner_; }
887
888 // Whether this stub table is empty.
889 bool
890 empty() const
891 {
892 return (this->reloc_stubs_.empty()
893 && this->cortex_a8_stubs_.empty()
894 && this->arm_v4bx_stubs_.empty());
895 }
896
897 // Return the current data size.
898 off_t
899 current_data_size() const
900 { return this->current_data_size_for_child(); }
901
902 // Add a STUB using KEY. The caller is responsible for avoiding addition
903 // if a STUB with the same key has already been added.
904 void
905 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
906 {
907 const Stub_template* stub_template = stub->stub_template();
908 gold_assert(stub_template->type() == key.stub_type());
909 this->reloc_stubs_[key] = stub;
910
911 // Assign stub offset early. We can do this because we never remove
912 // reloc stubs and they are in the beginning of the stub table.
913 uint64_t align = stub_template->alignment();
914 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915 stub->set_offset(this->reloc_stubs_size_);
916 this->reloc_stubs_size_ += stub_template->size();
917 this->reloc_stubs_addralign_ =
918 std::max(this->reloc_stubs_addralign_, align);
919 }
920
921 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922 // The caller is responsible for avoiding addition if a STUB with the same
923 // address has already been added.
924 void
925 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
926 {
927 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928 this->cortex_a8_stubs_.insert(value);
929 }
930
931 // Add an ARM V4BX relocation stub. A register index will be retrieved
932 // from the stub.
933 void
934 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
935 {
936 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937 this->arm_v4bx_stubs_[stub->reg()] = stub;
938 }
939
940 // Remove all Cortex-A8 stubs.
941 void
942 remove_all_cortex_a8_stubs();
943
944 // Look up a relocation stub using KEY. Return NULL if there is none.
945 Reloc_stub*
946 find_reloc_stub(const Reloc_stub::Key& key) const
947 {
948 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
950 }
951
952 // Look up an arm v4bx relocation stub using the register index.
953 // Return NULL if there is none.
954 Arm_v4bx_stub*
955 find_arm_v4bx_stub(const uint32_t reg) const
956 {
957 gold_assert(reg < 0xf);
958 return this->arm_v4bx_stubs_[reg];
959 }
960
961 // Relocate stubs in this stub table.
962 void
963 relocate_stubs(const Relocate_info<32, big_endian>*,
964 Target_arm<big_endian>*, Output_section*,
965 unsigned char*, Arm_address, section_size_type);
966
967 // Update data size and alignment at the end of a relaxation pass. Return
968 // true if either data size or alignment is different from that of the
969 // previous relaxation pass.
970 bool
971 update_data_size_and_addralign();
972
973 // Finalize stubs. Set the offsets of all stubs and mark input sections
974 // needing the Cortex-A8 workaround.
975 void
976 finalize_stubs();
977
978 // Apply Cortex-A8 workaround to an address range.
979 void
980 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981 unsigned char*, Arm_address,
982 section_size_type);
983
984 protected:
985 // Write out section contents.
986 void
987 do_write(Output_file*);
988
989 // Return the required alignment.
990 uint64_t
991 do_addralign() const
992 { return this->prev_addralign_; }
993
994 // Reset address and file offset.
995 void
996 do_reset_address_and_file_offset()
997 { this->set_current_data_size_for_child(this->prev_data_size_); }
998
999 // Set final data size.
1000 void
1001 set_final_data_size()
1002 { this->set_data_size(this->current_data_size()); }
1003
1004 private:
1005 // Relocate one stub.
1006 void
1007 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008 Target_arm<big_endian>*, Output_section*,
1009 unsigned char*, Arm_address, section_size_type);
1010
1011 // Unordered map of relocation stubs.
1012 typedef
1013 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014 Reloc_stub::Key::equal_to>
1015 Reloc_stub_map;
1016
1017 // List of Cortex-A8 stubs ordered by addresses of branches being
1018 // fixed up in output.
1019 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020 // List of Arm V4BX relocation stubs ordered by associated registers.
1021 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1022
1023 // Owner of this stub table.
1024 Arm_input_section<big_endian>* owner_;
1025 // The relocation stubs.
1026 Reloc_stub_map reloc_stubs_;
1027 // Size of reloc stubs.
1028 off_t reloc_stubs_size_;
1029 // Maximum address alignment of reloc stubs.
1030 uint64_t reloc_stubs_addralign_;
1031 // The cortex_a8_stubs.
1032 Cortex_a8_stub_list cortex_a8_stubs_;
1033 // The Arm V4BX relocation stubs.
1034 Arm_v4bx_stub_list arm_v4bx_stubs_;
1035 // data size of this in the previous pass.
1036 off_t prev_data_size_;
1037 // address alignment of this in the previous pass.
1038 uint64_t prev_addralign_;
1039 };
1040
1041 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1043
1044 class Arm_exidx_cantunwind : public Output_section_data
1045 {
1046 public:
1047 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1049 { }
1050
1051 // Return the object containing the section pointed by this.
1052 Relobj*
1053 relobj() const
1054 { return this->relobj_; }
1055
1056 // Return the section index of the section pointed by this.
1057 unsigned int
1058 shndx() const
1059 { return this->shndx_; }
1060
1061 protected:
1062 void
1063 do_write(Output_file* of)
1064 {
1065 if (parameters->target().is_big_endian())
1066 this->do_fixed_endian_write<true>(of);
1067 else
1068 this->do_fixed_endian_write<false>(of);
1069 }
1070
1071 // Write to a map file.
1072 void
1073 do_print_to_mapfile(Mapfile* mapfile) const
1074 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1075
1076 private:
1077 // Implement do_write for a given endianness.
1078 template<bool big_endian>
1079 void inline
1080 do_fixed_endian_write(Output_file*);
1081
1082 // The object containing the section pointed by this.
1083 Relobj* relobj_;
1084 // The section index of the section pointed by this.
1085 unsigned int shndx_;
1086 };
1087
1088 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1091
1092 typedef std::map<section_offset_type, section_offset_type>
1093 Arm_exidx_section_offset_map;
1094
1095 // Arm_exidx_merged_section class. This represents an EXIDX input section
1096 // with some of its entries merged.
1097
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1099 {
1100 public:
1101 // Constructor for Arm_exidx_merged_section.
1102 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103 // SECTION_OFFSET_MAP points to a section offset map describing how
1104 // parts of the input section are mapped to output. DELETED_BYTES is
1105 // the number of bytes deleted from the EXIDX input section.
1106 Arm_exidx_merged_section(
1107 const Arm_exidx_input_section& exidx_input_section,
1108 const Arm_exidx_section_offset_map& section_offset_map,
1109 uint32_t deleted_bytes);
1110
1111 // Build output contents.
1112 void
1113 build_contents(const unsigned char*, section_size_type);
1114
1115 // Return the original EXIDX input section.
1116 const Arm_exidx_input_section&
1117 exidx_input_section() const
1118 { return this->exidx_input_section_; }
1119
1120 // Return the section offset map.
1121 const Arm_exidx_section_offset_map&
1122 section_offset_map() const
1123 { return this->section_offset_map_; }
1124
1125 protected:
1126 // Write merged section into file OF.
1127 void
1128 do_write(Output_file* of);
1129
1130 bool
1131 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132 section_offset_type*) const;
1133
1134 private:
1135 // Original EXIDX input section.
1136 const Arm_exidx_input_section& exidx_input_section_;
1137 // Section offset map.
1138 const Arm_exidx_section_offset_map& section_offset_map_;
1139 // Merged section contents. We need to keep build the merged section
1140 // and save it here to avoid accessing the original EXIDX section when
1141 // we cannot lock the sections' object.
1142 unsigned char* section_contents_;
1143 };
1144
1145 // A class to wrap an ordinary input section containing executable code.
1146
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1149 {
1150 public:
1151 Arm_input_section(Relobj* relobj, unsigned int shndx)
1152 : Output_relaxed_input_section(relobj, shndx, 1),
1153 original_addralign_(1), original_size_(0), stub_table_(NULL),
1154 original_contents_(NULL)
1155 { }
1156
1157 ~Arm_input_section()
1158 { delete[] this->original_contents_; }
1159
1160 // Initialize.
1161 void
1162 init();
1163
1164 // Whether this is a stub table owner.
1165 bool
1166 is_stub_table_owner() const
1167 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1168
1169 // Return the stub table.
1170 Stub_table<big_endian>*
1171 stub_table() const
1172 { return this->stub_table_; }
1173
1174 // Set the stub_table.
1175 void
1176 set_stub_table(Stub_table<big_endian>* stub_table)
1177 { this->stub_table_ = stub_table; }
1178
1179 // Downcast a base pointer to an Arm_input_section pointer. This is
1180 // not type-safe but we only use Arm_input_section not the base class.
1181 static Arm_input_section<big_endian>*
1182 as_arm_input_section(Output_relaxed_input_section* poris)
1183 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1184
1185 // Return the original size of the section.
1186 uint32_t
1187 original_size() const
1188 { return this->original_size_; }
1189
1190 protected:
1191 // Write data to output file.
1192 void
1193 do_write(Output_file*);
1194
1195 // Return required alignment of this.
1196 uint64_t
1197 do_addralign() const
1198 {
1199 if (this->is_stub_table_owner())
1200 return std::max(this->stub_table_->addralign(),
1201 static_cast<uint64_t>(this->original_addralign_));
1202 else
1203 return this->original_addralign_;
1204 }
1205
1206 // Finalize data size.
1207 void
1208 set_final_data_size();
1209
1210 // Reset address and file offset.
1211 void
1212 do_reset_address_and_file_offset();
1213
1214 // Output offset.
1215 bool
1216 do_output_offset(const Relobj* object, unsigned int shndx,
1217 section_offset_type offset,
1218 section_offset_type* poutput) const
1219 {
1220 if ((object == this->relobj())
1221 && (shndx == this->shndx())
1222 && (offset >= 0)
1223 && (offset <=
1224 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1225 {
1226 *poutput = offset;
1227 return true;
1228 }
1229 else
1230 return false;
1231 }
1232
1233 private:
1234 // Copying is not allowed.
1235 Arm_input_section(const Arm_input_section&);
1236 Arm_input_section& operator=(const Arm_input_section&);
1237
1238 // Address alignment of the original input section.
1239 uint32_t original_addralign_;
1240 // Section size of the original input section.
1241 uint32_t original_size_;
1242 // Stub table.
1243 Stub_table<big_endian>* stub_table_;
1244 // Original section contents. We have to make a copy here since the file
1245 // containing the original section may not be locked when we need to access
1246 // the contents.
1247 unsigned char* original_contents_;
1248 };
1249
1250 // Arm_exidx_fixup class. This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1252
1253 class Arm_exidx_fixup
1254 {
1255 public:
1256 Arm_exidx_fixup(Output_section* exidx_output_section,
1257 bool merge_exidx_entries = true)
1258 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259 last_inlined_entry_(0), last_input_section_(NULL),
1260 section_offset_map_(NULL), first_output_text_section_(NULL),
1261 merge_exidx_entries_(merge_exidx_entries)
1262 { }
1263
1264 ~Arm_exidx_fixup()
1265 { delete this->section_offset_map_; }
1266
1267 // Process an EXIDX section for entry merging. SECTION_CONTENTS points
1268 // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269 // number of bytes to be deleted in output. If parts of the input EXIDX
1270 // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271 // in the located PSECTION_OFFSET_MAP. The caller owns the map and is
1272 // responsible for releasing it.
1273 template<bool big_endian>
1274 uint32_t
1275 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276 const unsigned char* section_contents,
1277 section_size_type section_size,
1278 Arm_exidx_section_offset_map** psection_offset_map);
1279
1280 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281 // input section, if there is not one already.
1282 void
1283 add_exidx_cantunwind_as_needed();
1284
1285 // Return the output section for the text section which is linked to the
1286 // first exidx input in output.
1287 Output_section*
1288 first_output_text_section() const
1289 { return this->first_output_text_section_; }
1290
1291 private:
1292 // Copying is not allowed.
1293 Arm_exidx_fixup(const Arm_exidx_fixup&);
1294 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1295
1296 // Type of EXIDX unwind entry.
1297 enum Unwind_type
1298 {
1299 // No type.
1300 UT_NONE,
1301 // EXIDX_CANTUNWIND.
1302 UT_EXIDX_CANTUNWIND,
1303 // Inlined entry.
1304 UT_INLINED_ENTRY,
1305 // Normal entry.
1306 UT_NORMAL_ENTRY,
1307 };
1308
1309 // Process an EXIDX entry. We only care about the second word of the
1310 // entry. Return true if the entry can be deleted.
1311 bool
1312 process_exidx_entry(uint32_t second_word);
1313
1314 // Update the current section offset map during EXIDX section fix-up.
1315 // If there is no map, create one. INPUT_OFFSET is the offset of a
1316 // reference point, DELETED_BYTES is the number of deleted by in the
1317 // section so far. If DELETE_ENTRY is true, the reference point and
1318 // all offsets after the previous reference point are discarded.
1319 void
1320 update_offset_map(section_offset_type input_offset,
1321 section_size_type deleted_bytes, bool delete_entry);
1322
1323 // EXIDX output section.
1324 Output_section* exidx_output_section_;
1325 // Unwind type of the last EXIDX entry processed.
1326 Unwind_type last_unwind_type_;
1327 // Last seen inlined EXIDX entry.
1328 uint32_t last_inlined_entry_;
1329 // Last processed EXIDX input section.
1330 const Arm_exidx_input_section* last_input_section_;
1331 // Section offset map created in process_exidx_section.
1332 Arm_exidx_section_offset_map* section_offset_map_;
1333 // Output section for the text section which is linked to the first exidx
1334 // input in output.
1335 Output_section* first_output_text_section_;
1336
1337 bool merge_exidx_entries_;
1338 };
1339
1340 // Arm output section class. This is defined mainly to add a number of
1341 // stub generation methods.
1342
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1345 {
1346 public:
1347 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1348
1349 // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351 elfcpp::Elf_Xword flags)
1352 : Output_section(name, type,
1353 (type == elfcpp::SHT_ARM_EXIDX
1354 ? flags | elfcpp::SHF_LINK_ORDER
1355 : flags))
1356 {
1357 if (type == elfcpp::SHT_ARM_EXIDX)
1358 this->set_always_keeps_input_sections();
1359 }
1360
1361 ~Arm_output_section()
1362 { }
1363
1364 // Group input sections for stub generation.
1365 void
1366 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1367
1368 // Downcast a base pointer to an Arm_output_section pointer. This is
1369 // not type-safe but we only use Arm_output_section not the base class.
1370 static Arm_output_section<big_endian>*
1371 as_arm_output_section(Output_section* os)
1372 { return static_cast<Arm_output_section<big_endian>*>(os); }
1373
1374 // Append all input text sections in this into LIST.
1375 void
1376 append_text_sections_to_list(Text_section_list* list);
1377
1378 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1379 // is a list of text input sections sorted in ascending order of their
1380 // output addresses.
1381 void
1382 fix_exidx_coverage(Layout* layout,
1383 const Text_section_list& sorted_text_section,
1384 Symbol_table* symtab,
1385 bool merge_exidx_entries,
1386 const Task* task);
1387
1388 // Link an EXIDX section into its corresponding text section.
1389 void
1390 set_exidx_section_link();
1391
1392 private:
1393 // For convenience.
1394 typedef Output_section::Input_section Input_section;
1395 typedef Output_section::Input_section_list Input_section_list;
1396
1397 // Create a stub group.
1398 void create_stub_group(Input_section_list::const_iterator,
1399 Input_section_list::const_iterator,
1400 Input_section_list::const_iterator,
1401 Target_arm<big_endian>*,
1402 std::vector<Output_relaxed_input_section*>*,
1403 const Task* task);
1404 };
1405
1406 // Arm_exidx_input_section class. This represents an EXIDX input section.
1407
1408 class Arm_exidx_input_section
1409 {
1410 public:
1411 static const section_offset_type invalid_offset =
1412 static_cast<section_offset_type>(-1);
1413
1414 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415 unsigned int link, uint32_t size,
1416 uint32_t addralign, uint32_t text_size)
1417 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418 addralign_(addralign), text_size_(text_size), has_errors_(false)
1419 { }
1420
1421 ~Arm_exidx_input_section()
1422 { }
1423
1424 // Accessors: This is a read-only class.
1425
1426 // Return the object containing this EXIDX input section.
1427 Relobj*
1428 relobj() const
1429 { return this->relobj_; }
1430
1431 // Return the section index of this EXIDX input section.
1432 unsigned int
1433 shndx() const
1434 { return this->shndx_; }
1435
1436 // Return the section index of linked text section in the same object.
1437 unsigned int
1438 link() const
1439 { return this->link_; }
1440
1441 // Return size of the EXIDX input section.
1442 uint32_t
1443 size() const
1444 { return this->size_; }
1445
1446 // Return address alignment of EXIDX input section.
1447 uint32_t
1448 addralign() const
1449 { return this->addralign_; }
1450
1451 // Return size of the associated text input section.
1452 uint32_t
1453 text_size() const
1454 { return this->text_size_; }
1455
1456 // Whether there are any errors in the EXIDX input section.
1457 bool
1458 has_errors() const
1459 { return this->has_errors_; }
1460
1461 // Set has-errors flag.
1462 void
1463 set_has_errors()
1464 { this->has_errors_ = true; }
1465
1466 private:
1467 // Object containing this.
1468 Relobj* relobj_;
1469 // Section index of this.
1470 unsigned int shndx_;
1471 // text section linked to this in the same object.
1472 unsigned int link_;
1473 // Size of this. For ARM 32-bit is sufficient.
1474 uint32_t size_;
1475 // Address alignment of this. For ARM 32-bit is sufficient.
1476 uint32_t addralign_;
1477 // Size of associated text section.
1478 uint32_t text_size_;
1479 // Whether this has any errors.
1480 bool has_errors_;
1481 };
1482
1483 // Arm_relobj class.
1484
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1487 {
1488 public:
1489 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1490
1491 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493 : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494 stub_tables_(), local_symbol_is_thumb_function_(),
1495 attributes_section_data_(NULL), mapping_symbols_info_(),
1496 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497 output_local_symbol_count_needs_update_(false),
1498 merge_flags_and_attributes_(true)
1499 { }
1500
1501 ~Arm_relobj()
1502 { delete this->attributes_section_data_; }
1503
1504 // Return the stub table of the SHNDX-th section if there is one.
1505 Stub_table<big_endian>*
1506 stub_table(unsigned int shndx) const
1507 {
1508 gold_assert(shndx < this->stub_tables_.size());
1509 return this->stub_tables_[shndx];
1510 }
1511
1512 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513 void
1514 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1515 {
1516 gold_assert(shndx < this->stub_tables_.size());
1517 this->stub_tables_[shndx] = stub_table;
1518 }
1519
1520 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1521 // index. This is only valid after do_count_local_symbol is called.
1522 bool
1523 local_symbol_is_thumb_function(unsigned int r_sym) const
1524 {
1525 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526 return this->local_symbol_is_thumb_function_[r_sym];
1527 }
1528
1529 // Scan all relocation sections for stub generation.
1530 void
1531 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532 const Layout*);
1533
1534 // Convert regular input section with index SHNDX to a relaxed section.
1535 void
1536 convert_input_section_to_relaxed_section(unsigned shndx)
1537 {
1538 // The stubs have relocations and we need to process them after writing
1539 // out the stubs. So relocation now must follow section write.
1540 this->set_section_offset(shndx, -1ULL);
1541 this->set_relocs_must_follow_section_writes();
1542 }
1543
1544 // Downcast a base pointer to an Arm_relobj pointer. This is
1545 // not type-safe but we only use Arm_relobj not the base class.
1546 static Arm_relobj<big_endian>*
1547 as_arm_relobj(Relobj* relobj)
1548 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1549
1550 // Processor-specific flags in ELF file header. This is valid only after
1551 // reading symbols.
1552 elfcpp::Elf_Word
1553 processor_specific_flags() const
1554 { return this->processor_specific_flags_; }
1555
1556 // Attribute section data This is the contents of the .ARM.attribute section
1557 // if there is one.
1558 const Attributes_section_data*
1559 attributes_section_data() const
1560 { return this->attributes_section_data_; }
1561
1562 // Mapping symbol location.
1563 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1564
1565 // Functor for STL container.
1566 struct Mapping_symbol_position_less
1567 {
1568 bool
1569 operator()(const Mapping_symbol_position& p1,
1570 const Mapping_symbol_position& p2) const
1571 {
1572 return (p1.first < p2.first
1573 || (p1.first == p2.first && p1.second < p2.second));
1574 }
1575 };
1576
1577 // We only care about the first character of a mapping symbol, so
1578 // we only store that instead of the whole symbol name.
1579 typedef std::map<Mapping_symbol_position, char,
1580 Mapping_symbol_position_less> Mapping_symbols_info;
1581
1582 // Whether a section contains any Cortex-A8 workaround.
1583 bool
1584 section_has_cortex_a8_workaround(unsigned int shndx) const
1585 {
1586 return (this->section_has_cortex_a8_workaround_ != NULL
1587 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1588 }
1589
1590 // Mark a section that has Cortex-A8 workaround.
1591 void
1592 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1593 {
1594 if (this->section_has_cortex_a8_workaround_ == NULL)
1595 this->section_has_cortex_a8_workaround_ =
1596 new std::vector<bool>(this->shnum(), false);
1597 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1598 }
1599
1600 // Return the EXIDX section of an text section with index SHNDX or NULL
1601 // if the text section has no associated EXIDX section.
1602 const Arm_exidx_input_section*
1603 exidx_input_section_by_link(unsigned int shndx) const
1604 {
1605 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606 return ((p != this->exidx_section_map_.end()
1607 && p->second->link() == shndx)
1608 ? p->second
1609 : NULL);
1610 }
1611
1612 // Return the EXIDX section with index SHNDX or NULL if there is none.
1613 const Arm_exidx_input_section*
1614 exidx_input_section_by_shndx(unsigned shndx) const
1615 {
1616 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617 return ((p != this->exidx_section_map_.end()
1618 && p->second->shndx() == shndx)
1619 ? p->second
1620 : NULL);
1621 }
1622
1623 // Whether output local symbol count needs updating.
1624 bool
1625 output_local_symbol_count_needs_update() const
1626 { return this->output_local_symbol_count_needs_update_; }
1627
1628 // Set output_local_symbol_count_needs_update flag to be true.
1629 void
1630 set_output_local_symbol_count_needs_update()
1631 { this->output_local_symbol_count_needs_update_ = true; }
1632
1633 // Update output local symbol count at the end of relaxation.
1634 void
1635 update_output_local_symbol_count();
1636
1637 // Whether we want to merge processor-specific flags and attributes.
1638 bool
1639 merge_flags_and_attributes() const
1640 { return this->merge_flags_and_attributes_; }
1641
1642 // Export list of EXIDX section indices.
1643 void
1644 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1645 {
1646 list->clear();
1647 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648 p != this->exidx_section_map_.end();
1649 ++p)
1650 {
1651 if (p->second->shndx() == p->first)
1652 list->push_back(p->first);
1653 }
1654 // Sort list to make result independent of implementation of map.
1655 std::sort(list->begin(), list->end());
1656 }
1657
1658 protected:
1659 // Post constructor setup.
1660 void
1661 do_setup()
1662 {
1663 // Call parent's setup method.
1664 Sized_relobj_file<32, big_endian>::do_setup();
1665
1666 // Initialize look-up tables.
1667 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668 this->stub_tables_.swap(empty_stub_table_list);
1669 }
1670
1671 // Count the local symbols.
1672 void
1673 do_count_local_symbols(Stringpool_template<char>*,
1674 Stringpool_template<char>*);
1675
1676 void
1677 do_relocate_sections(
1678 const Symbol_table* symtab, const Layout* layout,
1679 const unsigned char* pshdrs, Output_file* of,
1680 typename Sized_relobj_file<32, big_endian>::Views* pivews);
1681
1682 // Read the symbol information.
1683 void
1684 do_read_symbols(Read_symbols_data* sd);
1685
1686 // Process relocs for garbage collection.
1687 void
1688 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1689
1690 private:
1691
1692 // Whether a section needs to be scanned for relocation stubs.
1693 bool
1694 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695 const Relobj::Output_sections&,
1696 const Symbol_table*, const unsigned char*);
1697
1698 // Whether a section is a scannable text section.
1699 bool
1700 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701 const Output_section*, const Symbol_table*);
1702
1703 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704 bool
1705 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706 unsigned int, Output_section*,
1707 const Symbol_table*);
1708
1709 // Scan a section for the Cortex-A8 erratum.
1710 void
1711 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712 unsigned int, Output_section*,
1713 Target_arm<big_endian>*);
1714
1715 // Find the linked text section of an EXIDX section by looking at the
1716 // first relocation of the EXIDX section. PSHDR points to the section
1717 // headers of a relocation section and PSYMS points to the local symbols.
1718 // PSHNDX points to a location storing the text section index if found.
1719 // Return whether we can find the linked section.
1720 bool
1721 find_linked_text_section(const unsigned char* pshdr,
1722 const unsigned char* psyms, unsigned int* pshndx);
1723
1724 //
1725 // Make a new Arm_exidx_input_section object for EXIDX section with
1726 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1727 // index of the linked text section.
1728 void
1729 make_exidx_input_section(unsigned int shndx,
1730 const elfcpp::Shdr<32, big_endian>& shdr,
1731 unsigned int text_shndx,
1732 const elfcpp::Shdr<32, big_endian>& text_shdr);
1733
1734 // Return the output address of either a plain input section or a
1735 // relaxed input section. SHNDX is the section index.
1736 Arm_address
1737 simple_input_section_output_address(unsigned int, Output_section*);
1738
1739 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741 Exidx_section_map;
1742
1743 // List of stub tables.
1744 Stub_table_list stub_tables_;
1745 // Bit vector to tell if a local symbol is a thumb function or not.
1746 // This is only valid after do_count_local_symbol is called.
1747 std::vector<bool> local_symbol_is_thumb_function_;
1748 // processor-specific flags in ELF file header.
1749 elfcpp::Elf_Word processor_specific_flags_;
1750 // Object attributes if there is an .ARM.attributes section or NULL.
1751 Attributes_section_data* attributes_section_data_;
1752 // Mapping symbols information.
1753 Mapping_symbols_info mapping_symbols_info_;
1754 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755 std::vector<bool>* section_has_cortex_a8_workaround_;
1756 // Map a text section to its associated .ARM.exidx section, if there is one.
1757 Exidx_section_map exidx_section_map_;
1758 // Whether output local symbol count needs updating.
1759 bool output_local_symbol_count_needs_update_;
1760 // Whether we merge processor flags and attributes of this object to
1761 // output.
1762 bool merge_flags_and_attributes_;
1763 };
1764
1765 // Arm_dynobj class.
1766
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1769 {
1770 public:
1771 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772 const elfcpp::Ehdr<32, big_endian>& ehdr)
1773 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774 processor_specific_flags_(0), attributes_section_data_(NULL)
1775 { }
1776
1777 ~Arm_dynobj()
1778 { delete this->attributes_section_data_; }
1779
1780 // Downcast a base pointer to an Arm_relobj pointer. This is
1781 // not type-safe but we only use Arm_relobj not the base class.
1782 static Arm_dynobj<big_endian>*
1783 as_arm_dynobj(Dynobj* dynobj)
1784 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1785
1786 // Processor-specific flags in ELF file header. This is valid only after
1787 // reading symbols.
1788 elfcpp::Elf_Word
1789 processor_specific_flags() const
1790 { return this->processor_specific_flags_; }
1791
1792 // Attributes section data.
1793 const Attributes_section_data*
1794 attributes_section_data() const
1795 { return this->attributes_section_data_; }
1796
1797 protected:
1798 // Read the symbol information.
1799 void
1800 do_read_symbols(Read_symbols_data* sd);
1801
1802 private:
1803 // processor-specific flags in ELF file header.
1804 elfcpp::Elf_Word processor_specific_flags_;
1805 // Object attributes if there is an .ARM.attributes section or NULL.
1806 Attributes_section_data* attributes_section_data_;
1807 };
1808
1809 // Functor to read reloc addends during stub generation.
1810
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1813 {
1814 // Return the addend for a relocation of a particular type. Depending
1815 // on whether this is a REL or RELA relocation, read the addend from a
1816 // view or from a Reloc object.
1817 elfcpp::Elf_types<32>::Elf_Swxword
1818 operator()(
1819 unsigned int /* r_type */,
1820 const unsigned char* /* view */,
1821 const typename Reloc_types<sh_type,
1822 32, big_endian>::Reloc& /* reloc */) const;
1823 };
1824
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1826
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1829 {
1830 elfcpp::Elf_types<32>::Elf_Swxword
1831 operator()(
1832 unsigned int,
1833 const unsigned char*,
1834 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1835 };
1836
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader. This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1841
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1844 {
1845 elfcpp::Elf_types<32>::Elf_Swxword
1846 operator()(
1847 unsigned int,
1848 const unsigned char*,
1849 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850 big_endian>::Reloc& reloc) const
1851 { return reloc.get_r_addend(); }
1852 };
1853
1854 // Cortex_a8_reloc class. We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1856
1857 class Cortex_a8_reloc
1858 {
1859 public:
1860 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861 Arm_address destination)
1862 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1863 { }
1864
1865 ~Cortex_a8_reloc()
1866 { }
1867
1868 // Accessors: This is a read-only class.
1869
1870 // Return the relocation stub associated with this relocation if there is
1871 // one.
1872 const Reloc_stub*
1873 reloc_stub() const
1874 { return this->reloc_stub_; }
1875
1876 // Return the relocation type.
1877 unsigned int
1878 r_type() const
1879 { return this->r_type_; }
1880
1881 // Return the destination address of the relocation. LSB stores the THUMB
1882 // bit.
1883 Arm_address
1884 destination() const
1885 { return this->destination_; }
1886
1887 private:
1888 // Associated relocation stub if there is one, or NULL.
1889 const Reloc_stub* reloc_stub_;
1890 // Relocation type.
1891 unsigned int r_type_;
1892 // Destination address of this relocation. LSB is used to distinguish
1893 // ARM/THUMB mode.
1894 Arm_address destination_;
1895 };
1896
1897 // Arm_output_data_got class. We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1899
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1902 {
1903 public:
1904 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1906 { }
1907
1908 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1909 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910 // applied in a static link.
1911 void
1912 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1914
1915 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1916 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1917 // relocation that needs to be applied in a static link.
1918 void
1919 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920 Sized_relobj_file<32, big_endian>* relobj,
1921 unsigned int index)
1922 {
1923 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924 index));
1925 }
1926
1927 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1928 // The first one is initialized to be 1, which is the module index for
1929 // the main executable and the second one 0. A reloc of the type
1930 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931 // be applied by gold. GSYM is a global symbol.
1932 void
1933 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1934
1935 // Same as the above but for a local symbol in OBJECT with INDEX.
1936 void
1937 add_tls_gd32_with_static_reloc(unsigned int got_type,
1938 Sized_relobj_file<32, big_endian>* object,
1939 unsigned int index);
1940
1941 protected:
1942 // Write out the GOT table.
1943 void
1944 do_write(Output_file*);
1945
1946 private:
1947 // This class represent dynamic relocations that need to be applied by
1948 // gold because we are using TLS relocations in a static link.
1949 class Static_reloc
1950 {
1951 public:
1952 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954 { this->u_.global.symbol = gsym; }
1955
1956 Static_reloc(unsigned int got_offset, unsigned int r_type,
1957 Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1959 {
1960 this->u_.local.relobj = relobj;
1961 this->u_.local.index = index;
1962 }
1963
1964 // Return the GOT offset.
1965 unsigned int
1966 got_offset() const
1967 { return this->got_offset_; }
1968
1969 // Relocation type.
1970 unsigned int
1971 r_type() const
1972 { return this->r_type_; }
1973
1974 // Whether the symbol is global or not.
1975 bool
1976 symbol_is_global() const
1977 { return this->symbol_is_global_; }
1978
1979 // For a relocation against a global symbol, the global symbol.
1980 Symbol*
1981 symbol() const
1982 {
1983 gold_assert(this->symbol_is_global_);
1984 return this->u_.global.symbol;
1985 }
1986
1987 // For a relocation against a local symbol, the defining object.
1988 Sized_relobj_file<32, big_endian>*
1989 relobj() const
1990 {
1991 gold_assert(!this->symbol_is_global_);
1992 return this->u_.local.relobj;
1993 }
1994
1995 // For a relocation against a local symbol, the local symbol index.
1996 unsigned int
1997 index() const
1998 {
1999 gold_assert(!this->symbol_is_global_);
2000 return this->u_.local.index;
2001 }
2002
2003 private:
2004 // GOT offset of the entry to which this relocation is applied.
2005 unsigned int got_offset_;
2006 // Type of relocation.
2007 unsigned int r_type_;
2008 // Whether this relocation is against a global symbol.
2009 bool symbol_is_global_;
2010 // A global or local symbol.
2011 union
2012 {
2013 struct
2014 {
2015 // For a global symbol, the symbol itself.
2016 Symbol* symbol;
2017 } global;
2018 struct
2019 {
2020 // For a local symbol, the object defining object.
2021 Sized_relobj_file<32, big_endian>* relobj;
2022 // For a local symbol, the symbol index.
2023 unsigned int index;
2024 } local;
2025 } u_;
2026 };
2027
2028 // Symbol table of the output object.
2029 Symbol_table* symbol_table_;
2030 // Layout of the output object.
2031 Layout* layout_;
2032 // Static relocs to be applied to the GOT.
2033 std::vector<Static_reloc> static_relocs_;
2034 };
2035
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits. The default handling of relocatable relocation cannot process these
2038 // relocations. So we have to extend the default code.
2039
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2043 {
2044 public:
2045 // Return the strategy to use for a local symbol which is a section
2046 // symbol, given the relocation type.
2047 inline Relocatable_relocs::Reloc_strategy
2048 local_section_strategy(unsigned int r_type, Relobj*)
2049 {
2050 if (sh_type == elfcpp::SHT_RELA)
2051 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052 else
2053 {
2054 if (r_type == elfcpp::R_ARM_TARGET1
2055 || r_type == elfcpp::R_ARM_TARGET2)
2056 {
2057 const Target_arm<big_endian>* arm_target =
2058 Target_arm<big_endian>::default_target();
2059 r_type = arm_target->get_real_reloc_type(r_type);
2060 }
2061
2062 switch(r_type)
2063 {
2064 // Relocations that write nothing. These exclude R_ARM_TARGET1
2065 // and R_ARM_TARGET2.
2066 case elfcpp::R_ARM_NONE:
2067 case elfcpp::R_ARM_V4BX:
2068 case elfcpp::R_ARM_TLS_GOTDESC:
2069 case elfcpp::R_ARM_TLS_CALL:
2070 case elfcpp::R_ARM_TLS_DESCSEQ:
2071 case elfcpp::R_ARM_THM_TLS_CALL:
2072 case elfcpp::R_ARM_GOTRELAX:
2073 case elfcpp::R_ARM_GNU_VTENTRY:
2074 case elfcpp::R_ARM_GNU_VTINHERIT:
2075 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078 // These should have been converted to something else above.
2079 case elfcpp::R_ARM_TARGET1:
2080 case elfcpp::R_ARM_TARGET2:
2081 gold_unreachable();
2082 // Relocations that write full 32 bits and
2083 // have alignment of 1.
2084 case elfcpp::R_ARM_ABS32:
2085 case elfcpp::R_ARM_REL32:
2086 case elfcpp::R_ARM_SBREL32:
2087 case elfcpp::R_ARM_GOTOFF32:
2088 case elfcpp::R_ARM_BASE_PREL:
2089 case elfcpp::R_ARM_GOT_BREL:
2090 case elfcpp::R_ARM_BASE_ABS:
2091 case elfcpp::R_ARM_ABS32_NOI:
2092 case elfcpp::R_ARM_REL32_NOI:
2093 case elfcpp::R_ARM_PLT32_ABS:
2094 case elfcpp::R_ARM_GOT_ABS:
2095 case elfcpp::R_ARM_GOT_PREL:
2096 case elfcpp::R_ARM_TLS_GD32:
2097 case elfcpp::R_ARM_TLS_LDM32:
2098 case elfcpp::R_ARM_TLS_LDO32:
2099 case elfcpp::R_ARM_TLS_IE32:
2100 case elfcpp::R_ARM_TLS_LE32:
2101 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102 default:
2103 // For all other static relocations, return RELOC_SPECIAL.
2104 return Relocatable_relocs::RELOC_SPECIAL;
2105 }
2106 }
2107 }
2108 };
2109
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2112 {
2113 public:
2114 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115 Reloc_section;
2116
2117 // When were are relocating a stub, we pass this as the relocation number.
2118 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2119
2120 Target_arm(const Target::Target_info* info = &arm_info)
2121 : Sized_target<32, big_endian>(info),
2122 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
2123 rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY),
2124 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126 should_force_pic_veneer_(false),
2127 arm_input_section_map_(), attributes_section_data_(NULL),
2128 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2129 { }
2130
2131 // Whether we force PCI branch veneers.
2132 bool
2133 should_force_pic_veneer() const
2134 { return this->should_force_pic_veneer_; }
2135
2136 // Set PIC veneer flag.
2137 void
2138 set_should_force_pic_veneer(bool value)
2139 { this->should_force_pic_veneer_ = value; }
2140
2141 // Whether we use THUMB-2 instructions.
2142 bool
2143 using_thumb2() const
2144 {
2145 Object_attribute* attr =
2146 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147 int arch = attr->int_value();
2148 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2149 }
2150
2151 // Whether we use THUMB/THUMB-2 instructions only.
2152 bool
2153 using_thumb_only() const
2154 {
2155 Object_attribute* attr =
2156 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2157
2158 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160 return true;
2161 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163 return false;
2164 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165 return attr->int_value() == 'M';
2166 }
2167
2168 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2169 bool
2170 may_use_arm_nop() const
2171 {
2172 Object_attribute* attr =
2173 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174 int arch = attr->int_value();
2175 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176 || arch == elfcpp::TAG_CPU_ARCH_V6K
2177 || arch == elfcpp::TAG_CPU_ARCH_V7
2178 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2179 }
2180
2181 // Whether we have THUMB-2 NOP.W instruction.
2182 bool
2183 may_use_thumb2_nop() const
2184 {
2185 Object_attribute* attr =
2186 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187 int arch = attr->int_value();
2188 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189 || arch == elfcpp::TAG_CPU_ARCH_V7
2190 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2191 }
2192
2193 // Whether we have v4T interworking instructions available.
2194 bool
2195 may_use_v4t_interworking() const
2196 {
2197 Object_attribute* attr =
2198 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199 int arch = attr->int_value();
2200 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201 && arch != elfcpp::TAG_CPU_ARCH_V4);
2202 }
2203
2204 // Whether we have v5T interworking instructions available.
2205 bool
2206 may_use_v5t_interworking() const
2207 {
2208 Object_attribute* attr =
2209 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210 int arch = attr->int_value();
2211 if (parameters->options().fix_arm1176())
2212 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213 || arch == elfcpp::TAG_CPU_ARCH_V7
2214 || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215 || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217 else
2218 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219 && arch != elfcpp::TAG_CPU_ARCH_V4
2220 && arch != elfcpp::TAG_CPU_ARCH_V4T);
2221 }
2222
2223 // Process the relocations to determine unreferenced sections for
2224 // garbage collection.
2225 void
2226 gc_process_relocs(Symbol_table* symtab,
2227 Layout* layout,
2228 Sized_relobj_file<32, big_endian>* object,
2229 unsigned int data_shndx,
2230 unsigned int sh_type,
2231 const unsigned char* prelocs,
2232 size_t reloc_count,
2233 Output_section* output_section,
2234 bool needs_special_offset_handling,
2235 size_t local_symbol_count,
2236 const unsigned char* plocal_symbols);
2237
2238 // Scan the relocations to look for symbol adjustments.
2239 void
2240 scan_relocs(Symbol_table* symtab,
2241 Layout* layout,
2242 Sized_relobj_file<32, big_endian>* object,
2243 unsigned int data_shndx,
2244 unsigned int sh_type,
2245 const unsigned char* prelocs,
2246 size_t reloc_count,
2247 Output_section* output_section,
2248 bool needs_special_offset_handling,
2249 size_t local_symbol_count,
2250 const unsigned char* plocal_symbols);
2251
2252 // Finalize the sections.
2253 void
2254 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2255
2256 // Return the value to use for a dynamic symbol which requires special
2257 // treatment.
2258 uint64_t
2259 do_dynsym_value(const Symbol*) const;
2260
2261 // Return the plt address for globals. Since we have irelative plt entries,
2262 // address calculation is not as straightforward as plt_address + plt_offset.
2263 uint64_t
2264 do_plt_address_for_global(const Symbol* gsym) const
2265 { return this->plt_section()->address_for_global(gsym); }
2266
2267 // Return the plt address for locals. Since we have irelative plt entries,
2268 // address calculation is not as straightforward as plt_address + plt_offset.
2269 uint64_t
2270 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
2271 { return this->plt_section()->address_for_local(relobj, symndx); }
2272
2273 // Relocate a section.
2274 void
2275 relocate_section(const Relocate_info<32, big_endian>*,
2276 unsigned int sh_type,
2277 const unsigned char* prelocs,
2278 size_t reloc_count,
2279 Output_section* output_section,
2280 bool needs_special_offset_handling,
2281 unsigned char* view,
2282 Arm_address view_address,
2283 section_size_type view_size,
2284 const Reloc_symbol_changes*);
2285
2286 // Scan the relocs during a relocatable link.
2287 void
2288 scan_relocatable_relocs(Symbol_table* symtab,
2289 Layout* layout,
2290 Sized_relobj_file<32, big_endian>* object,
2291 unsigned int data_shndx,
2292 unsigned int sh_type,
2293 const unsigned char* prelocs,
2294 size_t reloc_count,
2295 Output_section* output_section,
2296 bool needs_special_offset_handling,
2297 size_t local_symbol_count,
2298 const unsigned char* plocal_symbols,
2299 Relocatable_relocs*);
2300
2301 // Emit relocations for a section.
2302 void
2303 relocate_relocs(const Relocate_info<32, big_endian>*,
2304 unsigned int sh_type,
2305 const unsigned char* prelocs,
2306 size_t reloc_count,
2307 Output_section* output_section,
2308 typename elfcpp::Elf_types<32>::Elf_Off
2309 offset_in_output_section,
2310 const Relocatable_relocs*,
2311 unsigned char* view,
2312 Arm_address view_address,
2313 section_size_type view_size,
2314 unsigned char* reloc_view,
2315 section_size_type reloc_view_size);
2316
2317 // Perform target-specific processing in a relocatable link. This is
2318 // only used if we use the relocation strategy RELOC_SPECIAL.
2319 void
2320 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2321 unsigned int sh_type,
2322 const unsigned char* preloc_in,
2323 size_t relnum,
2324 Output_section* output_section,
2325 typename elfcpp::Elf_types<32>::Elf_Off
2326 offset_in_output_section,
2327 unsigned char* view,
2328 typename elfcpp::Elf_types<32>::Elf_Addr
2329 view_address,
2330 section_size_type view_size,
2331 unsigned char* preloc_out);
2332
2333 // Return whether SYM is defined by the ABI.
2334 bool
2335 do_is_defined_by_abi(const Symbol* sym) const
2336 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2337
2338 // Return whether there is a GOT section.
2339 bool
2340 has_got_section() const
2341 { return this->got_ != NULL; }
2342
2343 // Return the size of the GOT section.
2344 section_size_type
2345 got_size() const
2346 {
2347 gold_assert(this->got_ != NULL);
2348 return this->got_->data_size();
2349 }
2350
2351 // Return the number of entries in the GOT.
2352 unsigned int
2353 got_entry_count() const
2354 {
2355 if (!this->has_got_section())
2356 return 0;
2357 return this->got_size() / 4;
2358 }
2359
2360 // Return the number of entries in the PLT.
2361 unsigned int
2362 plt_entry_count() const;
2363
2364 // Return the offset of the first non-reserved PLT entry.
2365 unsigned int
2366 first_plt_entry_offset() const;
2367
2368 // Return the size of each PLT entry.
2369 unsigned int
2370 plt_entry_size() const;
2371
2372 // Get the section to use for IRELATIVE relocations, create it if necessary.
2373 Reloc_section*
2374 rel_irelative_section(Layout*);
2375
2376 // Map platform-specific reloc types
2377 static unsigned int
2378 get_real_reloc_type(unsigned int r_type);
2379
2380 //
2381 // Methods to support stub-generations.
2382 //
2383
2384 // Return the stub factory
2385 const Stub_factory&
2386 stub_factory() const
2387 { return this->stub_factory_; }
2388
2389 // Make a new Arm_input_section object.
2390 Arm_input_section<big_endian>*
2391 new_arm_input_section(Relobj*, unsigned int);
2392
2393 // Find the Arm_input_section object corresponding to the SHNDX-th input
2394 // section of RELOBJ.
2395 Arm_input_section<big_endian>*
2396 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2397
2398 // Make a new Stub_table
2399 Stub_table<big_endian>*
2400 new_stub_table(Arm_input_section<big_endian>*);
2401
2402 // Scan a section for stub generation.
2403 void
2404 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2405 const unsigned char*, size_t, Output_section*,
2406 bool, const unsigned char*, Arm_address,
2407 section_size_type);
2408
2409 // Relocate a stub.
2410 void
2411 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2412 Output_section*, unsigned char*, Arm_address,
2413 section_size_type);
2414
2415 // Get the default ARM target.
2416 static Target_arm<big_endian>*
2417 default_target()
2418 {
2419 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2420 && parameters->target().is_big_endian() == big_endian);
2421 return static_cast<Target_arm<big_endian>*>(
2422 parameters->sized_target<32, big_endian>());
2423 }
2424
2425 // Whether NAME belongs to a mapping symbol.
2426 static bool
2427 is_mapping_symbol_name(const char* name)
2428 {
2429 return (name
2430 && name[0] == '$'
2431 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2432 && (name[2] == '\0' || name[2] == '.'));
2433 }
2434
2435 // Whether we work around the Cortex-A8 erratum.
2436 bool
2437 fix_cortex_a8() const
2438 { return this->fix_cortex_a8_; }
2439
2440 // Whether we merge exidx entries in debuginfo.
2441 bool
2442 merge_exidx_entries() const
2443 { return parameters->options().merge_exidx_entries(); }
2444
2445 // Whether we fix R_ARM_V4BX relocation.
2446 // 0 - do not fix
2447 // 1 - replace with MOV instruction (armv4 target)
2448 // 2 - make interworking veneer (>= armv4t targets only)
2449 General_options::Fix_v4bx
2450 fix_v4bx() const
2451 { return parameters->options().fix_v4bx(); }
2452
2453 // Scan a span of THUMB code section for Cortex-A8 erratum.
2454 void
2455 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2456 section_size_type, section_size_type,
2457 const unsigned char*, Arm_address);
2458
2459 // Apply Cortex-A8 workaround to a branch.
2460 void
2461 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2462 unsigned char*, Arm_address);
2463
2464 protected:
2465 // Make the PLT-generator object.
2466 Output_data_plt_arm<big_endian>*
2467 make_data_plt(Layout* layout,
2468 Arm_output_data_got<big_endian>* got,
2469 Output_data_space* got_plt,
2470 Output_data_space* got_irelative)
2471 { return this->do_make_data_plt(layout, got, got_plt, got_irelative); }
2472
2473 // Make an ELF object.
2474 Object*
2475 do_make_elf_object(const std::string&, Input_file*, off_t,
2476 const elfcpp::Ehdr<32, big_endian>& ehdr);
2477
2478 Object*
2479 do_make_elf_object(const std::string&, Input_file*, off_t,
2480 const elfcpp::Ehdr<32, !big_endian>&)
2481 { gold_unreachable(); }
2482
2483 Object*
2484 do_make_elf_object(const std::string&, Input_file*, off_t,
2485 const elfcpp::Ehdr<64, false>&)
2486 { gold_unreachable(); }
2487
2488 Object*
2489 do_make_elf_object(const std::string&, Input_file*, off_t,
2490 const elfcpp::Ehdr<64, true>&)
2491 { gold_unreachable(); }
2492
2493 // Make an output section.
2494 Output_section*
2495 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2496 elfcpp::Elf_Xword flags)
2497 { return new Arm_output_section<big_endian>(name, type, flags); }
2498
2499 void
2500 do_adjust_elf_header(unsigned char* view, int len);
2501
2502 // We only need to generate stubs, and hence perform relaxation if we are
2503 // not doing relocatable linking.
2504 bool
2505 do_may_relax() const
2506 { return !parameters->options().relocatable(); }
2507
2508 bool
2509 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2510
2511 // Determine whether an object attribute tag takes an integer, a
2512 // string or both.
2513 int
2514 do_attribute_arg_type(int tag) const;
2515
2516 // Reorder tags during output.
2517 int
2518 do_attributes_order(int num) const;
2519
2520 // This is called when the target is selected as the default.
2521 void
2522 do_select_as_default_target()
2523 {
2524 // No locking is required since there should only be one default target.
2525 // We cannot have both the big-endian and little-endian ARM targets
2526 // as the default.
2527 gold_assert(arm_reloc_property_table == NULL);
2528 arm_reloc_property_table = new Arm_reloc_property_table();
2529 }
2530
2531 // Virtual function which is set to return true by a target if
2532 // it can use relocation types to determine if a function's
2533 // pointer is taken.
2534 virtual bool
2535 do_can_check_for_function_pointers() const
2536 { return true; }
2537
2538 // Whether a section called SECTION_NAME may have function pointers to
2539 // sections not eligible for safe ICF folding.
2540 virtual bool
2541 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2542 {
2543 return (!is_prefix_of(".ARM.exidx", section_name)
2544 && !is_prefix_of(".ARM.extab", section_name)
2545 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2546 }
2547
2548 virtual void
2549 do_define_standard_symbols(Symbol_table*, Layout*);
2550
2551 virtual Output_data_plt_arm<big_endian>*
2552 do_make_data_plt(Layout* layout,
2553 Arm_output_data_got<big_endian>* got,
2554 Output_data_space* got_plt,
2555 Output_data_space* got_irelative)
2556 {
2557 gold_assert(got_plt != NULL && got_irelative != NULL);
2558 return new Output_data_plt_arm_standard<big_endian>(
2559 layout, got, got_plt, got_irelative);
2560 }
2561
2562 private:
2563 // The class which scans relocations.
2564 class Scan
2565 {
2566 public:
2567 Scan()
2568 : issued_non_pic_error_(false)
2569 { }
2570
2571 static inline int
2572 get_reference_flags(unsigned int r_type);
2573
2574 inline void
2575 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2576 Sized_relobj_file<32, big_endian>* object,
2577 unsigned int data_shndx,
2578 Output_section* output_section,
2579 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2580 const elfcpp::Sym<32, big_endian>& lsym,
2581 bool is_discarded);
2582
2583 inline void
2584 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2585 Sized_relobj_file<32, big_endian>* object,
2586 unsigned int data_shndx,
2587 Output_section* output_section,
2588 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2589 Symbol* gsym);
2590
2591 inline bool
2592 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2593 Sized_relobj_file<32, big_endian>* ,
2594 unsigned int ,
2595 Output_section* ,
2596 const elfcpp::Rel<32, big_endian>& ,
2597 unsigned int ,
2598 const elfcpp::Sym<32, big_endian>&);
2599
2600 inline bool
2601 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2602 Sized_relobj_file<32, big_endian>* ,
2603 unsigned int ,
2604 Output_section* ,
2605 const elfcpp::Rel<32, big_endian>& ,
2606 unsigned int , Symbol*);
2607
2608 private:
2609 static void
2610 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2611 unsigned int r_type);
2612
2613 static void
2614 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2615 unsigned int r_type, Symbol*);
2616
2617 void
2618 check_non_pic(Relobj*, unsigned int r_type);
2619
2620 // Almost identical to Symbol::needs_plt_entry except that it also
2621 // handles STT_ARM_TFUNC.
2622 static bool
2623 symbol_needs_plt_entry(const Symbol* sym)
2624 {
2625 // An undefined symbol from an executable does not need a PLT entry.
2626 if (sym->is_undefined() && !parameters->options().shared())
2627 return false;
2628
2629 if (sym->type() == elfcpp::STT_GNU_IFUNC)
2630 return true;
2631
2632 return (!parameters->doing_static_link()
2633 && (sym->type() == elfcpp::STT_FUNC
2634 || sym->type() == elfcpp::STT_ARM_TFUNC)
2635 && (sym->is_from_dynobj()
2636 || sym->is_undefined()
2637 || sym->is_preemptible()));
2638 }
2639
2640 inline bool
2641 possible_function_pointer_reloc(unsigned int r_type);
2642
2643 // Whether a plt entry is needed for ifunc.
2644 bool
2645 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*,
2646 unsigned int r_type);
2647
2648 // Whether we have issued an error about a non-PIC compilation.
2649 bool issued_non_pic_error_;
2650 };
2651
2652 // The class which implements relocation.
2653 class Relocate
2654 {
2655 public:
2656 Relocate()
2657 { }
2658
2659 ~Relocate()
2660 { }
2661
2662 // Return whether the static relocation needs to be applied.
2663 inline bool
2664 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2665 unsigned int r_type,
2666 bool is_32bit,
2667 Output_section* output_section);
2668
2669 // Do a relocation. Return false if the caller should not issue
2670 // any warnings about this relocation.
2671 inline bool
2672 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2673 Output_section*, size_t relnum,
2674 const elfcpp::Rel<32, big_endian>&,
2675 unsigned int r_type, const Sized_symbol<32>*,
2676 const Symbol_value<32>*,
2677 unsigned char*, Arm_address,
2678 section_size_type);
2679
2680 // Return whether we want to pass flag NON_PIC_REF for this
2681 // reloc. This means the relocation type accesses a symbol not via
2682 // GOT or PLT.
2683 static inline bool
2684 reloc_is_non_pic(unsigned int r_type)
2685 {
2686 switch (r_type)
2687 {
2688 // These relocation types reference GOT or PLT entries explicitly.
2689 case elfcpp::R_ARM_GOT_BREL:
2690 case elfcpp::R_ARM_GOT_ABS:
2691 case elfcpp::R_ARM_GOT_PREL:
2692 case elfcpp::R_ARM_GOT_BREL12:
2693 case elfcpp::R_ARM_PLT32_ABS:
2694 case elfcpp::R_ARM_TLS_GD32:
2695 case elfcpp::R_ARM_TLS_LDM32:
2696 case elfcpp::R_ARM_TLS_IE32:
2697 case elfcpp::R_ARM_TLS_IE12GP:
2698
2699 // These relocate types may use PLT entries.
2700 case elfcpp::R_ARM_CALL:
2701 case elfcpp::R_ARM_THM_CALL:
2702 case elfcpp::R_ARM_JUMP24:
2703 case elfcpp::R_ARM_THM_JUMP24:
2704 case elfcpp::R_ARM_THM_JUMP19:
2705 case elfcpp::R_ARM_PLT32:
2706 case elfcpp::R_ARM_THM_XPC22:
2707 case elfcpp::R_ARM_PREL31:
2708 case elfcpp::R_ARM_SBREL31:
2709 return false;
2710
2711 default:
2712 return true;
2713 }
2714 }
2715
2716 private:
2717 // Do a TLS relocation.
2718 inline typename Arm_relocate_functions<big_endian>::Status
2719 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2720 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2721 const Sized_symbol<32>*, const Symbol_value<32>*,
2722 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2723 section_size_type);
2724
2725 };
2726
2727 // A class which returns the size required for a relocation type,
2728 // used while scanning relocs during a relocatable link.
2729 class Relocatable_size_for_reloc
2730 {
2731 public:
2732 unsigned int
2733 get_size_for_reloc(unsigned int, Relobj*);
2734 };
2735
2736 // Adjust TLS relocation type based on the options and whether this
2737 // is a local symbol.
2738 static tls::Tls_optimization
2739 optimize_tls_reloc(bool is_final, int r_type);
2740
2741 // Get the GOT section, creating it if necessary.
2742 Arm_output_data_got<big_endian>*
2743 got_section(Symbol_table*, Layout*);
2744
2745 // Get the GOT PLT section.
2746 Output_data_space*
2747 got_plt_section() const
2748 {
2749 gold_assert(this->got_plt_ != NULL);
2750 return this->got_plt_;
2751 }
2752
2753 // Create the PLT section.
2754 void
2755 make_plt_section(Symbol_table* symtab, Layout* layout);
2756
2757 // Create a PLT entry for a global symbol.
2758 void
2759 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2760
2761 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
2762 void
2763 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
2764 Sized_relobj_file<32, big_endian>* relobj,
2765 unsigned int local_sym_index);
2766
2767 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2768 void
2769 define_tls_base_symbol(Symbol_table*, Layout*);
2770
2771 // Create a GOT entry for the TLS module index.
2772 unsigned int
2773 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2774 Sized_relobj_file<32, big_endian>* object);
2775
2776 // Get the PLT section.
2777 const Output_data_plt_arm<big_endian>*
2778 plt_section() const
2779 {
2780 gold_assert(this->plt_ != NULL);
2781 return this->plt_;
2782 }
2783
2784 // Get the dynamic reloc section, creating it if necessary.
2785 Reloc_section*
2786 rel_dyn_section(Layout*);
2787
2788 // Get the section to use for TLS_DESC relocations.
2789 Reloc_section*
2790 rel_tls_desc_section(Layout*) const;
2791
2792 // Return true if the symbol may need a COPY relocation.
2793 // References from an executable object to non-function symbols
2794 // defined in a dynamic object may need a COPY relocation.
2795 bool
2796 may_need_copy_reloc(Symbol* gsym)
2797 {
2798 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2799 && gsym->may_need_copy_reloc());
2800 }
2801
2802 // Add a potential copy relocation.
2803 void
2804 copy_reloc(Symbol_table* symtab, Layout* layout,
2805 Sized_relobj_file<32, big_endian>* object,
2806 unsigned int shndx, Output_section* output_section,
2807 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2808 {
2809 this->copy_relocs_.copy_reloc(symtab, layout,
2810 symtab->get_sized_symbol<32>(sym),
2811 object, shndx, output_section, reloc,
2812 this->rel_dyn_section(layout));
2813 }
2814
2815 // Whether two EABI versions are compatible.
2816 static bool
2817 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2818
2819 // Merge processor-specific flags from input object and those in the ELF
2820 // header of the output.
2821 void
2822 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2823
2824 // Get the secondary compatible architecture.
2825 static int
2826 get_secondary_compatible_arch(const Attributes_section_data*);
2827
2828 // Set the secondary compatible architecture.
2829 static void
2830 set_secondary_compatible_arch(Attributes_section_data*, int);
2831
2832 static int
2833 tag_cpu_arch_combine(const char*, int, int*, int, int);
2834
2835 // Helper to print AEABI enum tag value.
2836 static std::string
2837 aeabi_enum_name(unsigned int);
2838
2839 // Return string value for TAG_CPU_name.
2840 static std::string
2841 tag_cpu_name_value(unsigned int);
2842
2843 // Query attributes object to see if integer divide instructions may be
2844 // present in an object.
2845 static bool
2846 attributes_accept_div(int arch, int profile,
2847 const Object_attribute* div_attr);
2848
2849 // Query attributes object to see if integer divide instructions are
2850 // forbidden to be in the object. This is not the inverse of
2851 // attributes_accept_div.
2852 static bool
2853 attributes_forbid_div(const Object_attribute* div_attr);
2854
2855 // Merge object attributes from input object and those in the output.
2856 void
2857 merge_object_attributes(const char*, const Attributes_section_data*);
2858
2859 // Helper to get an AEABI object attribute
2860 Object_attribute*
2861 get_aeabi_object_attribute(int tag) const
2862 {
2863 Attributes_section_data* pasd = this->attributes_section_data_;
2864 gold_assert(pasd != NULL);
2865 Object_attribute* attr =
2866 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2867 gold_assert(attr != NULL);
2868 return attr;
2869 }
2870
2871 //
2872 // Methods to support stub-generations.
2873 //
2874
2875 // Group input sections for stub generation.
2876 void
2877 group_sections(Layout*, section_size_type, bool, const Task*);
2878
2879 // Scan a relocation for stub generation.
2880 void
2881 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2882 const Sized_symbol<32>*, unsigned int,
2883 const Symbol_value<32>*,
2884 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2885
2886 // Scan a relocation section for stub.
2887 template<int sh_type>
2888 void
2889 scan_reloc_section_for_stubs(
2890 const Relocate_info<32, big_endian>* relinfo,
2891 const unsigned char* prelocs,
2892 size_t reloc_count,
2893 Output_section* output_section,
2894 bool needs_special_offset_handling,
2895 const unsigned char* view,
2896 elfcpp::Elf_types<32>::Elf_Addr view_address,
2897 section_size_type);
2898
2899 // Fix .ARM.exidx section coverage.
2900 void
2901 fix_exidx_coverage(Layout*, const Input_objects*,
2902 Arm_output_section<big_endian>*, Symbol_table*,
2903 const Task*);
2904
2905 // Functors for STL set.
2906 struct output_section_address_less_than
2907 {
2908 bool
2909 operator()(const Output_section* s1, const Output_section* s2) const
2910 { return s1->address() < s2->address(); }
2911 };
2912
2913 // Information about this specific target which we pass to the
2914 // general Target structure.
2915 static const Target::Target_info arm_info;
2916
2917 // The types of GOT entries needed for this platform.
2918 // These values are exposed to the ABI in an incremental link.
2919 // Do not renumber existing values without changing the version
2920 // number of the .gnu_incremental_inputs section.
2921 enum Got_type
2922 {
2923 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2924 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2925 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2926 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2927 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2928 };
2929
2930 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2931
2932 // Map input section to Arm_input_section.
2933 typedef Unordered_map<Section_id,
2934 Arm_input_section<big_endian>*,
2935 Section_id_hash>
2936 Arm_input_section_map;
2937
2938 // Map output addresses to relocs for Cortex-A8 erratum.
2939 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2940 Cortex_a8_relocs_info;
2941
2942 // The GOT section.
2943 Arm_output_data_got<big_endian>* got_;
2944 // The PLT section.
2945 Output_data_plt_arm<big_endian>* plt_;
2946 // The GOT PLT section.
2947 Output_data_space* got_plt_;
2948 // The GOT section for IRELATIVE relocations.
2949 Output_data_space* got_irelative_;
2950 // The dynamic reloc section.
2951 Reloc_section* rel_dyn_;
2952 // The section to use for IRELATIVE relocs.
2953 Reloc_section* rel_irelative_;
2954 // Relocs saved to avoid a COPY reloc.
2955 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2956 // Offset of the GOT entry for the TLS module index.
2957 unsigned int got_mod_index_offset_;
2958 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2959 bool tls_base_symbol_defined_;
2960 // Vector of Stub_tables created.
2961 Stub_table_list stub_tables_;
2962 // Stub factory.
2963 const Stub_factory &stub_factory_;
2964 // Whether we force PIC branch veneers.
2965 bool should_force_pic_veneer_;
2966 // Map for locating Arm_input_sections.
2967 Arm_input_section_map arm_input_section_map_;
2968 // Attributes section data in output.
2969 Attributes_section_data* attributes_section_data_;
2970 // Whether we want to fix code for Cortex-A8 erratum.
2971 bool fix_cortex_a8_;
2972 // Map addresses to relocs for Cortex-A8 erratum.
2973 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2974 };
2975
2976 template<bool big_endian>
2977 const Target::Target_info Target_arm<big_endian>::arm_info =
2978 {
2979 32, // size
2980 big_endian, // is_big_endian
2981 elfcpp::EM_ARM, // machine_code
2982 false, // has_make_symbol
2983 false, // has_resolve
2984 false, // has_code_fill
2985 true, // is_default_stack_executable
2986 false, // can_icf_inline_merge_sections
2987 '\0', // wrap_char
2988 "/usr/lib/libc.so.1", // dynamic_linker
2989 0x8000, // default_text_segment_address
2990 0x1000, // abi_pagesize (overridable by -z max-page-size)
2991 0x1000, // common_pagesize (overridable by -z common-page-size)
2992 false, // isolate_execinstr
2993 0, // rosegment_gap
2994 elfcpp::SHN_UNDEF, // small_common_shndx
2995 elfcpp::SHN_UNDEF, // large_common_shndx
2996 0, // small_common_section_flags
2997 0, // large_common_section_flags
2998 ".ARM.attributes", // attributes_section
2999 "aeabi", // attributes_vendor
3000 "_start" // entry_symbol_name
3001 };
3002
3003 // Arm relocate functions class
3004 //
3005
3006 template<bool big_endian>
3007 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
3008 {
3009 public:
3010 typedef enum
3011 {
3012 STATUS_OKAY, // No error during relocation.
3013 STATUS_OVERFLOW, // Relocation overflow.
3014 STATUS_BAD_RELOC // Relocation cannot be applied.
3015 } Status;
3016
3017 private:
3018 typedef Relocate_functions<32, big_endian> Base;
3019 typedef Arm_relocate_functions<big_endian> This;
3020
3021 // Encoding of imm16 argument for movt and movw ARM instructions
3022 // from ARM ARM:
3023 //
3024 // imm16 := imm4 | imm12
3025 //
3026 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
3027 // +-------+---------------+-------+-------+-----------------------+
3028 // | | |imm4 | |imm12 |
3029 // +-------+---------------+-------+-------+-----------------------+
3030
3031 // Extract the relocation addend from VAL based on the ARM
3032 // instruction encoding described above.
3033 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3034 extract_arm_movw_movt_addend(
3035 typename elfcpp::Swap<32, big_endian>::Valtype val)
3036 {
3037 // According to the Elf ABI for ARM Architecture the immediate
3038 // field is sign-extended to form the addend.
3039 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
3040 }
3041
3042 // Insert X into VAL based on the ARM instruction encoding described
3043 // above.
3044 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3045 insert_val_arm_movw_movt(
3046 typename elfcpp::Swap<32, big_endian>::Valtype val,
3047 typename elfcpp::Swap<32, big_endian>::Valtype x)
3048 {
3049 val &= 0xfff0f000;
3050 val |= x & 0x0fff;
3051 val |= (x & 0xf000) << 4;
3052 return val;
3053 }
3054
3055 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3056 // from ARM ARM:
3057 //
3058 // imm16 := imm4 | i | imm3 | imm8
3059 //
3060 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
3061 // +---------+-+-----------+-------++-+-----+-------+---------------+
3062 // | |i| |imm4 || |imm3 | |imm8 |
3063 // +---------+-+-----------+-------++-+-----+-------+---------------+
3064
3065 // Extract the relocation addend from VAL based on the Thumb2
3066 // instruction encoding described above.
3067 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3068 extract_thumb_movw_movt_addend(
3069 typename elfcpp::Swap<32, big_endian>::Valtype val)
3070 {
3071 // According to the Elf ABI for ARM Architecture the immediate
3072 // field is sign-extended to form the addend.
3073 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3074 | ((val >> 15) & 0x0800)
3075 | ((val >> 4) & 0x0700)
3076 | (val & 0x00ff));
3077 }
3078
3079 // Insert X into VAL based on the Thumb2 instruction encoding
3080 // described above.
3081 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3082 insert_val_thumb_movw_movt(
3083 typename elfcpp::Swap<32, big_endian>::Valtype val,
3084 typename elfcpp::Swap<32, big_endian>::Valtype x)
3085 {
3086 val &= 0xfbf08f00;
3087 val |= (x & 0xf000) << 4;
3088 val |= (x & 0x0800) << 15;
3089 val |= (x & 0x0700) << 4;
3090 val |= (x & 0x00ff);
3091 return val;
3092 }
3093
3094 // Calculate the smallest constant Kn for the specified residual.
3095 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3096 static uint32_t
3097 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3098 {
3099 int32_t msb;
3100
3101 if (residual == 0)
3102 return 0;
3103 // Determine the most significant bit in the residual and
3104 // align the resulting value to a 2-bit boundary.
3105 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3106 ;
3107 // The desired shift is now (msb - 6), or zero, whichever
3108 // is the greater.
3109 return (((msb - 6) < 0) ? 0 : (msb - 6));
3110 }
3111
3112 // Calculate the final residual for the specified group index.
3113 // If the passed group index is less than zero, the method will return
3114 // the value of the specified residual without any change.
3115 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3116 static typename elfcpp::Swap<32, big_endian>::Valtype
3117 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3118 const int group)
3119 {
3120 for (int n = 0; n <= group; n++)
3121 {
3122 // Calculate which part of the value to mask.
3123 uint32_t shift = calc_grp_kn(residual);
3124 // Calculate the residual for the next time around.
3125 residual &= ~(residual & (0xff << shift));
3126 }
3127
3128 return residual;
3129 }
3130
3131 // Calculate the value of Gn for the specified group index.
3132 // We return it in the form of an encoded constant-and-rotation.
3133 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3134 static typename elfcpp::Swap<32, big_endian>::Valtype
3135 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3136 const int group)
3137 {
3138 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3139 uint32_t shift = 0;
3140
3141 for (int n = 0; n <= group; n++)
3142 {
3143 // Calculate which part of the value to mask.
3144 shift = calc_grp_kn(residual);
3145 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3146 gn = residual & (0xff << shift);
3147 // Calculate the residual for the next time around.
3148 residual &= ~gn;
3149 }
3150 // Return Gn in the form of an encoded constant-and-rotation.
3151 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3152 }
3153
3154 public:
3155 // Handle ARM long branches.
3156 static typename This::Status
3157 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3158 unsigned char*, const Sized_symbol<32>*,
3159 const Arm_relobj<big_endian>*, unsigned int,
3160 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3161
3162 // Handle THUMB long branches.
3163 static typename This::Status
3164 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3165 unsigned char*, const Sized_symbol<32>*,
3166 const Arm_relobj<big_endian>*, unsigned int,
3167 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3168
3169
3170 // Return the branch offset of a 32-bit THUMB branch.
3171 static inline int32_t
3172 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3173 {
3174 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3175 // involving the J1 and J2 bits.
3176 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3177 uint32_t upper = upper_insn & 0x3ffU;
3178 uint32_t lower = lower_insn & 0x7ffU;
3179 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3180 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3181 uint32_t i1 = j1 ^ s ? 0 : 1;
3182 uint32_t i2 = j2 ^ s ? 0 : 1;
3183
3184 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3185 | (upper << 12) | (lower << 1));
3186 }
3187
3188 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3189 // UPPER_INSN is the original upper instruction of the branch. Caller is
3190 // responsible for overflow checking and BLX offset adjustment.
3191 static inline uint16_t
3192 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3193 {
3194 uint32_t s = offset < 0 ? 1 : 0;
3195 uint32_t bits = static_cast<uint32_t>(offset);
3196 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3197 }
3198
3199 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3200 // LOWER_INSN is the original lower instruction of the branch. Caller is
3201 // responsible for overflow checking and BLX offset adjustment.
3202 static inline uint16_t
3203 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3204 {
3205 uint32_t s = offset < 0 ? 1 : 0;
3206 uint32_t bits = static_cast<uint32_t>(offset);
3207 return ((lower_insn & ~0x2fffU)
3208 | ((((bits >> 23) & 1) ^ !s) << 13)
3209 | ((((bits >> 22) & 1) ^ !s) << 11)
3210 | ((bits >> 1) & 0x7ffU));
3211 }
3212
3213 // Return the branch offset of a 32-bit THUMB conditional branch.
3214 static inline int32_t
3215 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3216 {
3217 uint32_t s = (upper_insn & 0x0400U) >> 10;
3218 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3219 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3220 uint32_t lower = (lower_insn & 0x07ffU);
3221 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3222
3223 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3224 }
3225
3226 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3227 // instruction. UPPER_INSN is the original upper instruction of the branch.
3228 // Caller is responsible for overflow checking.
3229 static inline uint16_t
3230 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3231 {
3232 uint32_t s = offset < 0 ? 1 : 0;
3233 uint32_t bits = static_cast<uint32_t>(offset);
3234 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3235 }
3236
3237 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3238 // instruction. LOWER_INSN is the original lower instruction of the branch.
3239 // The caller is responsible for overflow checking.
3240 static inline uint16_t
3241 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3242 {
3243 uint32_t bits = static_cast<uint32_t>(offset);
3244 uint32_t j2 = (bits & 0x00080000U) >> 19;
3245 uint32_t j1 = (bits & 0x00040000U) >> 18;
3246 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3247
3248 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3249 }
3250
3251 // R_ARM_ABS8: S + A
3252 static inline typename This::Status
3253 abs8(unsigned char* view,
3254 const Sized_relobj_file<32, big_endian>* object,
3255 const Symbol_value<32>* psymval)
3256 {
3257 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3258 Valtype* wv = reinterpret_cast<Valtype*>(view);
3259 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3260 int32_t addend = Bits<8>::sign_extend32(val);
3261 Arm_address x = psymval->value(object, addend);
3262 val = Bits<32>::bit_select32(val, x, 0xffU);
3263 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3264
3265 // R_ARM_ABS8 permits signed or unsigned results.
3266 return (Bits<8>::has_signed_unsigned_overflow32(x)
3267 ? This::STATUS_OVERFLOW
3268 : This::STATUS_OKAY);
3269 }
3270
3271 // R_ARM_THM_ABS5: S + A
3272 static inline typename This::Status
3273 thm_abs5(unsigned char* view,
3274 const Sized_relobj_file<32, big_endian>* object,
3275 const Symbol_value<32>* psymval)
3276 {
3277 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3278 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3279 Valtype* wv = reinterpret_cast<Valtype*>(view);
3280 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3281 Reltype addend = (val & 0x7e0U) >> 6;
3282 Reltype x = psymval->value(object, addend);
3283 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3284 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3285 return (Bits<5>::has_overflow32(x)
3286 ? This::STATUS_OVERFLOW
3287 : This::STATUS_OKAY);
3288 }
3289
3290 // R_ARM_ABS12: S + A
3291 static inline typename This::Status
3292 abs12(unsigned char* view,
3293 const Sized_relobj_file<32, big_endian>* object,
3294 const Symbol_value<32>* psymval)
3295 {
3296 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3297 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3298 Valtype* wv = reinterpret_cast<Valtype*>(view);
3299 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3300 Reltype addend = val & 0x0fffU;
3301 Reltype x = psymval->value(object, addend);
3302 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3303 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3304 return (Bits<12>::has_overflow32(x)
3305 ? This::STATUS_OVERFLOW
3306 : This::STATUS_OKAY);
3307 }
3308
3309 // R_ARM_ABS16: S + A
3310 static inline typename This::Status
3311 abs16(unsigned char* view,
3312 const Sized_relobj_file<32, big_endian>* object,
3313 const Symbol_value<32>* psymval)
3314 {
3315 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3316 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3317 int32_t addend = Bits<16>::sign_extend32(val);
3318 Arm_address x = psymval->value(object, addend);
3319 val = Bits<32>::bit_select32(val, x, 0xffffU);
3320 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3321
3322 // R_ARM_ABS16 permits signed or unsigned results.
3323 return (Bits<16>::has_signed_unsigned_overflow32(x)
3324 ? This::STATUS_OVERFLOW
3325 : This::STATUS_OKAY);
3326 }
3327
3328 // R_ARM_ABS32: (S + A) | T
3329 static inline typename This::Status
3330 abs32(unsigned char* view,
3331 const Sized_relobj_file<32, big_endian>* object,
3332 const Symbol_value<32>* psymval,
3333 Arm_address thumb_bit)
3334 {
3335 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3336 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3337 Valtype x = psymval->value(object, addend) | thumb_bit;
3338 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3339 return This::STATUS_OKAY;
3340 }
3341
3342 // R_ARM_REL32: (S + A) | T - P
3343 static inline typename This::Status
3344 rel32(unsigned char* view,
3345 const Sized_relobj_file<32, big_endian>* object,
3346 const Symbol_value<32>* psymval,
3347 Arm_address address,
3348 Arm_address thumb_bit)
3349 {
3350 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3351 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3352 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3353 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3354 return This::STATUS_OKAY;
3355 }
3356
3357 // R_ARM_THM_JUMP24: (S + A) | T - P
3358 static typename This::Status
3359 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3360 const Symbol_value<32>* psymval, Arm_address address,
3361 Arm_address thumb_bit);
3362
3363 // R_ARM_THM_JUMP6: S + A – P
3364 static inline typename This::Status
3365 thm_jump6(unsigned char* view,
3366 const Sized_relobj_file<32, big_endian>* object,
3367 const Symbol_value<32>* psymval,
3368 Arm_address address)
3369 {
3370 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3371 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3372 Valtype* wv = reinterpret_cast<Valtype*>(view);
3373 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3374 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3375 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3376 Reltype x = (psymval->value(object, addend) - address);
3377 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3378 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3379 // CZB does only forward jumps.
3380 return ((x > 0x007e)
3381 ? This::STATUS_OVERFLOW
3382 : This::STATUS_OKAY);
3383 }
3384
3385 // R_ARM_THM_JUMP8: S + A – P
3386 static inline typename This::Status
3387 thm_jump8(unsigned char* view,
3388 const Sized_relobj_file<32, big_endian>* object,
3389 const Symbol_value<32>* psymval,
3390 Arm_address address)
3391 {
3392 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3393 Valtype* wv = reinterpret_cast<Valtype*>(view);
3394 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3395 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3396 int32_t x = (psymval->value(object, addend) - address);
3397 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3398 | ((x & 0x01fe) >> 1)));
3399 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3400 return (Bits<9>::has_overflow32(x)
3401 ? This::STATUS_OVERFLOW
3402 : This::STATUS_OKAY);
3403 }
3404
3405 // R_ARM_THM_JUMP11: S + A – P
3406 static inline typename This::Status
3407 thm_jump11(unsigned char* view,
3408 const Sized_relobj_file<32, big_endian>* object,
3409 const Symbol_value<32>* psymval,
3410 Arm_address address)
3411 {
3412 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3413 Valtype* wv = reinterpret_cast<Valtype*>(view);
3414 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3415 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3416 int32_t x = (psymval->value(object, addend) - address);
3417 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3418 | ((x & 0x0ffe) >> 1)));
3419 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3420 return (Bits<12>::has_overflow32(x)
3421 ? This::STATUS_OVERFLOW
3422 : This::STATUS_OKAY);
3423 }
3424
3425 // R_ARM_BASE_PREL: B(S) + A - P
3426 static inline typename This::Status
3427 base_prel(unsigned char* view,
3428 Arm_address origin,
3429 Arm_address address)
3430 {
3431 Base::rel32(view, origin - address);
3432 return STATUS_OKAY;
3433 }
3434
3435 // R_ARM_BASE_ABS: B(S) + A
3436 static inline typename This::Status
3437 base_abs(unsigned char* view,
3438 Arm_address origin)
3439 {
3440 Base::rel32(view, origin);
3441 return STATUS_OKAY;
3442 }
3443
3444 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3445 static inline typename This::Status
3446 got_brel(unsigned char* view,
3447 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3448 {
3449 Base::rel32(view, got_offset);
3450 return This::STATUS_OKAY;
3451 }
3452
3453 // R_ARM_GOT_PREL: GOT(S) + A - P
3454 static inline typename This::Status
3455 got_prel(unsigned char* view,
3456 Arm_address got_entry,
3457 Arm_address address)
3458 {
3459 Base::rel32(view, got_entry - address);
3460 return This::STATUS_OKAY;
3461 }
3462
3463 // R_ARM_PREL: (S + A) | T - P
3464 static inline typename This::Status
3465 prel31(unsigned char* view,
3466 const Sized_relobj_file<32, big_endian>* object,
3467 const Symbol_value<32>* psymval,
3468 Arm_address address,
3469 Arm_address thumb_bit)
3470 {
3471 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3472 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3473 Valtype addend = Bits<31>::sign_extend32(val);
3474 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3475 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3476 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3477 return (Bits<31>::has_overflow32(x)
3478 ? This::STATUS_OVERFLOW
3479 : This::STATUS_OKAY);
3480 }
3481
3482 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3483 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3484 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3485 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3486 static inline typename This::Status
3487 movw(unsigned char* view,
3488 const Sized_relobj_file<32, big_endian>* object,
3489 const Symbol_value<32>* psymval,
3490 Arm_address relative_address_base,
3491 Arm_address thumb_bit,
3492 bool check_overflow)
3493 {
3494 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3495 Valtype* wv = reinterpret_cast<Valtype*>(view);
3496 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3497 Valtype addend = This::extract_arm_movw_movt_addend(val);
3498 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3499 - relative_address_base);
3500 val = This::insert_val_arm_movw_movt(val, x);
3501 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3502 return ((check_overflow && Bits<16>::has_overflow32(x))
3503 ? This::STATUS_OVERFLOW
3504 : This::STATUS_OKAY);
3505 }
3506
3507 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3508 // R_ARM_MOVT_PREL: S + A - P
3509 // R_ARM_MOVT_BREL: S + A - B(S)
3510 static inline typename This::Status
3511 movt(unsigned char* view,
3512 const Sized_relobj_file<32, big_endian>* object,
3513 const Symbol_value<32>* psymval,
3514 Arm_address relative_address_base)
3515 {
3516 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3517 Valtype* wv = reinterpret_cast<Valtype*>(view);
3518 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3519 Valtype addend = This::extract_arm_movw_movt_addend(val);
3520 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3521 val = This::insert_val_arm_movw_movt(val, x);
3522 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3523 // FIXME: IHI0044D says that we should check for overflow.
3524 return This::STATUS_OKAY;
3525 }
3526
3527 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3528 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3529 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3530 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3531 static inline typename This::Status
3532 thm_movw(unsigned char* view,
3533 const Sized_relobj_file<32, big_endian>* object,
3534 const Symbol_value<32>* psymval,
3535 Arm_address relative_address_base,
3536 Arm_address thumb_bit,
3537 bool check_overflow)
3538 {
3539 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3540 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3541 Valtype* wv = reinterpret_cast<Valtype*>(view);
3542 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3543 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3544 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3545 Reltype x =
3546 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3547 val = This::insert_val_thumb_movw_movt(val, x);
3548 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3549 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3550 return ((check_overflow && Bits<16>::has_overflow32(x))
3551 ? This::STATUS_OVERFLOW
3552 : This::STATUS_OKAY);
3553 }
3554
3555 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3556 // R_ARM_THM_MOVT_PREL: S + A - P
3557 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3558 static inline typename This::Status
3559 thm_movt(unsigned char* view,
3560 const Sized_relobj_file<32, big_endian>* object,
3561 const Symbol_value<32>* psymval,
3562 Arm_address relative_address_base)
3563 {
3564 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3565 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3566 Valtype* wv = reinterpret_cast<Valtype*>(view);
3567 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3568 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3569 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3570 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3571 val = This::insert_val_thumb_movw_movt(val, x);
3572 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3573 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3574 return This::STATUS_OKAY;
3575 }
3576
3577 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3578 static inline typename This::Status
3579 thm_alu11(unsigned char* view,
3580 const Sized_relobj_file<32, big_endian>* object,
3581 const Symbol_value<32>* psymval,
3582 Arm_address address,
3583 Arm_address thumb_bit)
3584 {
3585 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3586 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3587 Valtype* wv = reinterpret_cast<Valtype*>(view);
3588 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3589 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3590
3591 // f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3592 // -----------------------------------------------------------------------
3593 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3594 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3595 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3596 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3597 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3598 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3599
3600 // Determine a sign for the addend.
3601 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3602 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3603 // Thumb2 addend encoding:
3604 // imm12 := i | imm3 | imm8
3605 int32_t addend = (insn & 0xff)
3606 | ((insn & 0x00007000) >> 4)
3607 | ((insn & 0x04000000) >> 15);
3608 // Apply a sign to the added.
3609 addend *= sign;
3610
3611 int32_t x = (psymval->value(object, addend) | thumb_bit)
3612 - (address & 0xfffffffc);
3613 Reltype val = abs(x);
3614 // Mask out the value and a distinct part of the ADD/SUB opcode
3615 // (bits 7:5 of opword).
3616 insn = (insn & 0xfb0f8f00)
3617 | (val & 0xff)
3618 | ((val & 0x700) << 4)
3619 | ((val & 0x800) << 15);
3620 // Set the opcode according to whether the value to go in the
3621 // place is negative.
3622 if (x < 0)
3623 insn |= 0x00a00000;
3624
3625 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3626 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3627 return ((val > 0xfff) ?
3628 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3629 }
3630
3631 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3632 static inline typename This::Status
3633 thm_pc8(unsigned char* view,
3634 const Sized_relobj_file<32, big_endian>* object,
3635 const Symbol_value<32>* psymval,
3636 Arm_address address)
3637 {
3638 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3639 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3640 Valtype* wv = reinterpret_cast<Valtype*>(view);
3641 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3642 Reltype addend = ((insn & 0x00ff) << 2);
3643 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3644 Reltype val = abs(x);
3645 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3646
3647 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3648 return ((val > 0x03fc)
3649 ? This::STATUS_OVERFLOW
3650 : This::STATUS_OKAY);
3651 }
3652
3653 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3654 static inline typename This::Status
3655 thm_pc12(unsigned char* view,
3656 const Sized_relobj_file<32, big_endian>* object,
3657 const Symbol_value<32>* psymval,
3658 Arm_address address)
3659 {
3660 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3661 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3662 Valtype* wv = reinterpret_cast<Valtype*>(view);
3663 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3664 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3665 // Determine a sign for the addend (positive if the U bit is 1).
3666 const int sign = (insn & 0x00800000) ? 1 : -1;
3667 int32_t addend = (insn & 0xfff);
3668 // Apply a sign to the added.
3669 addend *= sign;
3670
3671 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3672 Reltype val = abs(x);
3673 // Mask out and apply the value and the U bit.
3674 insn = (insn & 0xff7ff000) | (val & 0xfff);
3675 // Set the U bit according to whether the value to go in the
3676 // place is positive.
3677 if (x >= 0)
3678 insn |= 0x00800000;
3679
3680 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3681 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3682 return ((val > 0xfff) ?
3683 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3684 }
3685
3686 // R_ARM_V4BX
3687 static inline typename This::Status
3688 v4bx(const Relocate_info<32, big_endian>* relinfo,
3689 unsigned char* view,
3690 const Arm_relobj<big_endian>* object,
3691 const Arm_address address,
3692 const bool is_interworking)
3693 {
3694
3695 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3696 Valtype* wv = reinterpret_cast<Valtype*>(view);
3697 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3698
3699 // Ensure that we have a BX instruction.
3700 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3701 const uint32_t reg = (val & 0xf);
3702 if (is_interworking && reg != 0xf)
3703 {
3704 Stub_table<big_endian>* stub_table =
3705 object->stub_table(relinfo->data_shndx);
3706 gold_assert(stub_table != NULL);
3707
3708 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3709 gold_assert(stub != NULL);
3710
3711 int32_t veneer_address =
3712 stub_table->address() + stub->offset() - 8 - address;
3713 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3714 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3715 // Replace with a branch to veneer (B <addr>)
3716 val = (val & 0xf0000000) | 0x0a000000
3717 | ((veneer_address >> 2) & 0x00ffffff);
3718 }
3719 else
3720 {
3721 // Preserve Rm (lowest four bits) and the condition code
3722 // (highest four bits). Other bits encode MOV PC,Rm.
3723 val = (val & 0xf000000f) | 0x01a0f000;
3724 }
3725 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3726 return This::STATUS_OKAY;
3727 }
3728
3729 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3730 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3731 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3732 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3733 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3734 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3735 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3736 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3737 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3738 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3739 static inline typename This::Status
3740 arm_grp_alu(unsigned char* view,
3741 const Sized_relobj_file<32, big_endian>* object,
3742 const Symbol_value<32>* psymval,
3743 const int group,
3744 Arm_address address,
3745 Arm_address thumb_bit,
3746 bool check_overflow)
3747 {
3748 gold_assert(group >= 0 && group < 3);
3749 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3750 Valtype* wv = reinterpret_cast<Valtype*>(view);
3751 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3752
3753 // ALU group relocations are allowed only for the ADD/SUB instructions.
3754 // (0x00800000 - ADD, 0x00400000 - SUB)
3755 const Valtype opcode = insn & 0x01e00000;
3756 if (opcode != 0x00800000 && opcode != 0x00400000)
3757 return This::STATUS_BAD_RELOC;
3758
3759 // Determine a sign for the addend.
3760 const int sign = (opcode == 0x00800000) ? 1 : -1;
3761 // shifter = rotate_imm * 2
3762 const uint32_t shifter = (insn & 0xf00) >> 7;
3763 // Initial addend value.
3764 int32_t addend = insn & 0xff;
3765 // Rotate addend right by shifter.
3766 addend = (addend >> shifter) | (addend << (32 - shifter));
3767 // Apply a sign to the added.
3768 addend *= sign;
3769
3770 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3771 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3772 // Check for overflow if required
3773 if (check_overflow
3774 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3775 return This::STATUS_OVERFLOW;
3776
3777 // Mask out the value and the ADD/SUB part of the opcode; take care
3778 // not to destroy the S bit.
3779 insn &= 0xff1ff000;
3780 // Set the opcode according to whether the value to go in the
3781 // place is negative.
3782 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3783 // Encode the offset (encoded Gn).
3784 insn |= gn;
3785
3786 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3787 return This::STATUS_OKAY;
3788 }
3789
3790 // R_ARM_LDR_PC_G0: S + A - P
3791 // R_ARM_LDR_PC_G1: S + A - P
3792 // R_ARM_LDR_PC_G2: S + A - P
3793 // R_ARM_LDR_SB_G0: S + A - B(S)
3794 // R_ARM_LDR_SB_G1: S + A - B(S)
3795 // R_ARM_LDR_SB_G2: S + A - B(S)
3796 static inline typename This::Status
3797 arm_grp_ldr(unsigned char* view,
3798 const Sized_relobj_file<32, big_endian>* object,
3799 const Symbol_value<32>* psymval,
3800 const int group,
3801 Arm_address address)
3802 {
3803 gold_assert(group >= 0 && group < 3);
3804 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3805 Valtype* wv = reinterpret_cast<Valtype*>(view);
3806 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3807
3808 const int sign = (insn & 0x00800000) ? 1 : -1;
3809 int32_t addend = (insn & 0xfff) * sign;
3810 int32_t x = (psymval->value(object, addend) - address);
3811 // Calculate the relevant G(n-1) value to obtain this stage residual.
3812 Valtype residual =
3813 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3814 if (residual >= 0x1000)
3815 return This::STATUS_OVERFLOW;
3816
3817 // Mask out the value and U bit.
3818 insn &= 0xff7ff000;
3819 // Set the U bit for non-negative values.
3820 if (x >= 0)
3821 insn |= 0x00800000;
3822 insn |= residual;
3823
3824 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3825 return This::STATUS_OKAY;
3826 }
3827
3828 // R_ARM_LDRS_PC_G0: S + A - P
3829 // R_ARM_LDRS_PC_G1: S + A - P
3830 // R_ARM_LDRS_PC_G2: S + A - P
3831 // R_ARM_LDRS_SB_G0: S + A - B(S)
3832 // R_ARM_LDRS_SB_G1: S + A - B(S)
3833 // R_ARM_LDRS_SB_G2: S + A - B(S)
3834 static inline typename This::Status
3835 arm_grp_ldrs(unsigned char* view,
3836 const Sized_relobj_file<32, big_endian>* object,
3837 const Symbol_value<32>* psymval,
3838 const int group,
3839 Arm_address address)
3840 {
3841 gold_assert(group >= 0 && group < 3);
3842 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3843 Valtype* wv = reinterpret_cast<Valtype*>(view);
3844 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3845
3846 const int sign = (insn & 0x00800000) ? 1 : -1;
3847 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3848 int32_t x = (psymval->value(object, addend) - address);
3849 // Calculate the relevant G(n-1) value to obtain this stage residual.
3850 Valtype residual =
3851 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3852 if (residual >= 0x100)
3853 return This::STATUS_OVERFLOW;
3854
3855 // Mask out the value and U bit.
3856 insn &= 0xff7ff0f0;
3857 // Set the U bit for non-negative values.
3858 if (x >= 0)
3859 insn |= 0x00800000;
3860 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3861
3862 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3863 return This::STATUS_OKAY;
3864 }
3865
3866 // R_ARM_LDC_PC_G0: S + A - P
3867 // R_ARM_LDC_PC_G1: S + A - P
3868 // R_ARM_LDC_PC_G2: S + A - P
3869 // R_ARM_LDC_SB_G0: S + A - B(S)
3870 // R_ARM_LDC_SB_G1: S + A - B(S)
3871 // R_ARM_LDC_SB_G2: S + A - B(S)
3872 static inline typename This::Status
3873 arm_grp_ldc(unsigned char* view,
3874 const Sized_relobj_file<32, big_endian>* object,
3875 const Symbol_value<32>* psymval,
3876 const int group,
3877 Arm_address address)
3878 {
3879 gold_assert(group >= 0 && group < 3);
3880 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3881 Valtype* wv = reinterpret_cast<Valtype*>(view);
3882 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3883
3884 const int sign = (insn & 0x00800000) ? 1 : -1;
3885 int32_t addend = ((insn & 0xff) << 2) * sign;
3886 int32_t x = (psymval->value(object, addend) - address);
3887 // Calculate the relevant G(n-1) value to obtain this stage residual.
3888 Valtype residual =
3889 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3890 if ((residual & 0x3) != 0 || residual >= 0x400)
3891 return This::STATUS_OVERFLOW;
3892
3893 // Mask out the value and U bit.
3894 insn &= 0xff7fff00;
3895 // Set the U bit for non-negative values.
3896 if (x >= 0)
3897 insn |= 0x00800000;
3898 insn |= (residual >> 2);
3899
3900 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3901 return This::STATUS_OKAY;
3902 }
3903 };
3904
3905 // Relocate ARM long branches. This handles relocation types
3906 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3907 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3908 // undefined and we do not use PLT in this relocation. In such a case,
3909 // the branch is converted into an NOP.
3910
3911 template<bool big_endian>
3912 typename Arm_relocate_functions<big_endian>::Status
3913 Arm_relocate_functions<big_endian>::arm_branch_common(
3914 unsigned int r_type,
3915 const Relocate_info<32, big_endian>* relinfo,
3916 unsigned char* view,
3917 const Sized_symbol<32>* gsym,
3918 const Arm_relobj<big_endian>* object,
3919 unsigned int r_sym,
3920 const Symbol_value<32>* psymval,
3921 Arm_address address,
3922 Arm_address thumb_bit,
3923 bool is_weakly_undefined_without_plt)
3924 {
3925 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3926 Valtype* wv = reinterpret_cast<Valtype*>(view);
3927 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3928
3929 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3930 && ((val & 0x0f000000UL) == 0x0a000000UL);
3931 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3932 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3933 && ((val & 0x0f000000UL) == 0x0b000000UL);
3934 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3935 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3936
3937 // Check that the instruction is valid.
3938 if (r_type == elfcpp::R_ARM_CALL)
3939 {
3940 if (!insn_is_uncond_bl && !insn_is_blx)
3941 return This::STATUS_BAD_RELOC;
3942 }
3943 else if (r_type == elfcpp::R_ARM_JUMP24)
3944 {
3945 if (!insn_is_b && !insn_is_cond_bl)
3946 return This::STATUS_BAD_RELOC;
3947 }
3948 else if (r_type == elfcpp::R_ARM_PLT32)
3949 {
3950 if (!insn_is_any_branch)
3951 return This::STATUS_BAD_RELOC;
3952 }
3953 else if (r_type == elfcpp::R_ARM_XPC25)
3954 {
3955 // FIXME: AAELF document IH0044C does not say much about it other
3956 // than it being obsolete.
3957 if (!insn_is_any_branch)
3958 return This::STATUS_BAD_RELOC;
3959 }
3960 else
3961 gold_unreachable();
3962
3963 // A branch to an undefined weak symbol is turned into a jump to
3964 // the next instruction unless a PLT entry will be created.
3965 // Do the same for local undefined symbols.
3966 // The jump to the next instruction is optimized as a NOP depending
3967 // on the architecture.
3968 const Target_arm<big_endian>* arm_target =
3969 Target_arm<big_endian>::default_target();
3970 if (is_weakly_undefined_without_plt)
3971 {
3972 gold_assert(!parameters->options().relocatable());
3973 Valtype cond = val & 0xf0000000U;
3974 if (arm_target->may_use_arm_nop())
3975 val = cond | 0x0320f000;
3976 else
3977 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3978 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3979 return This::STATUS_OKAY;
3980 }
3981
3982 Valtype addend = Bits<26>::sign_extend32(val << 2);
3983 Valtype branch_target = psymval->value(object, addend);
3984 int32_t branch_offset = branch_target - address;
3985
3986 // We need a stub if the branch offset is too large or if we need
3987 // to switch mode.
3988 bool may_use_blx = arm_target->may_use_v5t_interworking();
3989 Reloc_stub* stub = NULL;
3990
3991 if (!parameters->options().relocatable()
3992 && (Bits<26>::has_overflow32(branch_offset)
3993 || ((thumb_bit != 0)
3994 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3995 {
3996 Valtype unadjusted_branch_target = psymval->value(object, 0);
3997
3998 Stub_type stub_type =
3999 Reloc_stub::stub_type_for_reloc(r_type, address,
4000 unadjusted_branch_target,
4001 (thumb_bit != 0));
4002 if (stub_type != arm_stub_none)
4003 {
4004 Stub_table<big_endian>* stub_table =
4005 object->stub_table(relinfo->data_shndx);
4006 gold_assert(stub_table != NULL);
4007
4008 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4009 stub = stub_table->find_reloc_stub(stub_key);
4010 gold_assert(stub != NULL);
4011 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4012 branch_target = stub_table->address() + stub->offset() + addend;
4013 branch_offset = branch_target - address;
4014 gold_assert(!Bits<26>::has_overflow32(branch_offset));
4015 }
4016 }
4017
4018 // At this point, if we still need to switch mode, the instruction
4019 // must either be a BLX or a BL that can be converted to a BLX.
4020 if (thumb_bit != 0)
4021 {
4022 // Turn BL to BLX.
4023 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
4024 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
4025 }
4026
4027 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
4028 elfcpp::Swap<32, big_endian>::writeval(wv, val);
4029 return (Bits<26>::has_overflow32(branch_offset)
4030 ? This::STATUS_OVERFLOW
4031 : This::STATUS_OKAY);
4032 }
4033
4034 // Relocate THUMB long branches. This handles relocation types
4035 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
4036 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4037 // undefined and we do not use PLT in this relocation. In such a case,
4038 // the branch is converted into an NOP.
4039
4040 template<bool big_endian>
4041 typename Arm_relocate_functions<big_endian>::Status
4042 Arm_relocate_functions<big_endian>::thumb_branch_common(
4043 unsigned int r_type,
4044 const Relocate_info<32, big_endian>* relinfo,
4045 unsigned char* view,
4046 const Sized_symbol<32>* gsym,
4047 const Arm_relobj<big_endian>* object,
4048 unsigned int r_sym,
4049 const Symbol_value<32>* psymval,
4050 Arm_address address,
4051 Arm_address thumb_bit,
4052 bool is_weakly_undefined_without_plt)
4053 {
4054 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4055 Valtype* wv = reinterpret_cast<Valtype*>(view);
4056 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4057 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4058
4059 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4060 // into account.
4061 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4062 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4063
4064 // Check that the instruction is valid.
4065 if (r_type == elfcpp::R_ARM_THM_CALL)
4066 {
4067 if (!is_bl_insn && !is_blx_insn)
4068 return This::STATUS_BAD_RELOC;
4069 }
4070 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4071 {
4072 // This cannot be a BLX.
4073 if (!is_bl_insn)
4074 return This::STATUS_BAD_RELOC;
4075 }
4076 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4077 {
4078 // Check for Thumb to Thumb call.
4079 if (!is_blx_insn)
4080 return This::STATUS_BAD_RELOC;
4081 if (thumb_bit != 0)
4082 {
4083 gold_warning(_("%s: Thumb BLX instruction targets "
4084 "thumb function '%s'."),
4085 object->name().c_str(),
4086 (gsym ? gsym->name() : "(local)"));
4087 // Convert BLX to BL.
4088 lower_insn |= 0x1000U;
4089 }
4090 }
4091 else
4092 gold_unreachable();
4093
4094 // A branch to an undefined weak symbol is turned into a jump to
4095 // the next instruction unless a PLT entry will be created.
4096 // The jump to the next instruction is optimized as a NOP.W for
4097 // Thumb-2 enabled architectures.
4098 const Target_arm<big_endian>* arm_target =
4099 Target_arm<big_endian>::default_target();
4100 if (is_weakly_undefined_without_plt)
4101 {
4102 gold_assert(!parameters->options().relocatable());
4103 if (arm_target->may_use_thumb2_nop())
4104 {
4105 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4106 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4107 }
4108 else
4109 {
4110 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4111 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4112 }
4113 return This::STATUS_OKAY;
4114 }
4115
4116 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4117 Arm_address branch_target = psymval->value(object, addend);
4118
4119 // For BLX, bit 1 of target address comes from bit 1 of base address.
4120 bool may_use_blx = arm_target->may_use_v5t_interworking();
4121 if (thumb_bit == 0 && may_use_blx)
4122 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4123
4124 int32_t branch_offset = branch_target - address;
4125
4126 // We need a stub if the branch offset is too large or if we need
4127 // to switch mode.
4128 bool thumb2 = arm_target->using_thumb2();
4129 if (!parameters->options().relocatable()
4130 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4131 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4132 || ((thumb_bit == 0)
4133 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4134 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4135 {
4136 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4137
4138 Stub_type stub_type =
4139 Reloc_stub::stub_type_for_reloc(r_type, address,
4140 unadjusted_branch_target,
4141 (thumb_bit != 0));
4142
4143 if (stub_type != arm_stub_none)
4144 {
4145 Stub_table<big_endian>* stub_table =
4146 object->stub_table(relinfo->data_shndx);
4147 gold_assert(stub_table != NULL);
4148
4149 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4150 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4151 gold_assert(stub != NULL);
4152 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4153 branch_target = stub_table->address() + stub->offset() + addend;
4154 if (thumb_bit == 0 && may_use_blx)
4155 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4156 branch_offset = branch_target - address;
4157 }
4158 }
4159
4160 // At this point, if we still need to switch mode, the instruction
4161 // must either be a BLX or a BL that can be converted to a BLX.
4162 if (thumb_bit == 0)
4163 {
4164 gold_assert(may_use_blx
4165 && (r_type == elfcpp::R_ARM_THM_CALL
4166 || r_type == elfcpp::R_ARM_THM_XPC22));
4167 // Make sure this is a BLX.
4168 lower_insn &= ~0x1000U;
4169 }
4170 else
4171 {
4172 // Make sure this is a BL.
4173 lower_insn |= 0x1000U;
4174 }
4175
4176 // For a BLX instruction, make sure that the relocation is rounded up
4177 // to a word boundary. This follows the semantics of the instruction
4178 // which specifies that bit 1 of the target address will come from bit
4179 // 1 of the base address.
4180 if ((lower_insn & 0x5000U) == 0x4000U)
4181 gold_assert((branch_offset & 3) == 0);
4182
4183 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4184 // We use the Thumb-2 encoding, which is safe even if dealing with
4185 // a Thumb-1 instruction by virtue of our overflow check above. */
4186 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4187 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4188
4189 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4190 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4191
4192 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4193
4194 return ((thumb2
4195 ? Bits<25>::has_overflow32(branch_offset)
4196 : Bits<23>::has_overflow32(branch_offset))
4197 ? This::STATUS_OVERFLOW
4198 : This::STATUS_OKAY);
4199 }
4200
4201 // Relocate THUMB-2 long conditional branches.
4202 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4203 // undefined and we do not use PLT in this relocation. In such a case,
4204 // the branch is converted into an NOP.
4205
4206 template<bool big_endian>
4207 typename Arm_relocate_functions<big_endian>::Status
4208 Arm_relocate_functions<big_endian>::thm_jump19(
4209 unsigned char* view,
4210 const Arm_relobj<big_endian>* object,
4211 const Symbol_value<32>* psymval,
4212 Arm_address address,
4213 Arm_address thumb_bit)
4214 {
4215 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4216 Valtype* wv = reinterpret_cast<Valtype*>(view);
4217 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4218 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4219 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4220
4221 Arm_address branch_target = psymval->value(object, addend);
4222 int32_t branch_offset = branch_target - address;
4223
4224 // ??? Should handle interworking? GCC might someday try to
4225 // use this for tail calls.
4226 // FIXME: We do support thumb entry to PLT yet.
4227 if (thumb_bit == 0)
4228 {
4229 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4230 return This::STATUS_BAD_RELOC;
4231 }
4232
4233 // Put RELOCATION back into the insn.
4234 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4235 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4236
4237 // Put the relocated value back in the object file:
4238 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4239 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4240
4241 return (Bits<21>::has_overflow32(branch_offset)
4242 ? This::STATUS_OVERFLOW
4243 : This::STATUS_OKAY);
4244 }
4245
4246 // Get the GOT section, creating it if necessary.
4247
4248 template<bool big_endian>
4249 Arm_output_data_got<big_endian>*
4250 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4251 {
4252 if (this->got_ == NULL)
4253 {
4254 gold_assert(symtab != NULL && layout != NULL);
4255
4256 // When using -z now, we can treat .got as a relro section.
4257 // Without -z now, it is modified after program startup by lazy
4258 // PLT relocations.
4259 bool is_got_relro = parameters->options().now();
4260 Output_section_order got_order = (is_got_relro
4261 ? ORDER_RELRO_LAST
4262 : ORDER_DATA);
4263
4264 // Unlike some targets (.e.g x86), ARM does not use separate .got and
4265 // .got.plt sections in output. The output .got section contains both
4266 // PLT and non-PLT GOT entries.
4267 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4268
4269 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4270 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4271 this->got_, got_order, is_got_relro);
4272
4273 // The old GNU linker creates a .got.plt section. We just
4274 // create another set of data in the .got section. Note that we
4275 // always create a PLT if we create a GOT, although the PLT
4276 // might be empty.
4277 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4278 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4279 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4280 this->got_plt_, got_order, is_got_relro);
4281
4282 // The first three entries are reserved.
4283 this->got_plt_->set_current_data_size(3 * 4);
4284
4285 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4286 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4287 Symbol_table::PREDEFINED,
4288 this->got_plt_,
4289 0, 0, elfcpp::STT_OBJECT,
4290 elfcpp::STB_LOCAL,
4291 elfcpp::STV_HIDDEN, 0,
4292 false, false);
4293
4294 // If there are any IRELATIVE relocations, they get GOT entries
4295 // in .got.plt after the jump slot entries.
4296 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
4297 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4298 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4299 this->got_irelative_,
4300 got_order, is_got_relro);
4301
4302 }
4303 return this->got_;
4304 }
4305
4306 // Get the dynamic reloc section, creating it if necessary.
4307
4308 template<bool big_endian>
4309 typename Target_arm<big_endian>::Reloc_section*
4310 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4311 {
4312 if (this->rel_dyn_ == NULL)
4313 {
4314 gold_assert(layout != NULL);
4315 // Create both relocation sections in the same place, so as to ensure
4316 // their relative order in the output section.
4317 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4318 this->rel_irelative_ = new Reloc_section(false);
4319 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4320 elfcpp::SHF_ALLOC, this->rel_dyn_,
4321 ORDER_DYNAMIC_RELOCS, false);
4322 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4323 elfcpp::SHF_ALLOC, this->rel_irelative_,
4324 ORDER_DYNAMIC_RELOCS, false);
4325 }
4326 return this->rel_dyn_;
4327 }
4328
4329
4330 // Get the section to use for IRELATIVE relocs, creating it if necessary. These
4331 // go in .rela.dyn, but only after all other dynamic relocations. They need to
4332 // follow the other dynamic relocations so that they can refer to global
4333 // variables initialized by those relocs.
4334
4335 template<bool big_endian>
4336 typename Target_arm<big_endian>::Reloc_section*
4337 Target_arm<big_endian>::rel_irelative_section(Layout* layout)
4338 {
4339 if (this->rel_irelative_ == NULL)
4340 {
4341 // Delegate the creation to rel_dyn_section so as to ensure their order in
4342 // the output section.
4343 this->rel_dyn_section(layout);
4344 gold_assert(this->rel_irelative_ != NULL
4345 && (this->rel_dyn_->output_section()
4346 == this->rel_irelative_->output_section()));
4347 }
4348 return this->rel_irelative_;
4349 }
4350
4351
4352 // Insn_template methods.
4353
4354 // Return byte size of an instruction template.
4355
4356 size_t
4357 Insn_template::size() const
4358 {
4359 switch (this->type())
4360 {
4361 case THUMB16_TYPE:
4362 case THUMB16_SPECIAL_TYPE:
4363 return 2;
4364 case ARM_TYPE:
4365 case THUMB32_TYPE:
4366 case DATA_TYPE:
4367 return 4;
4368 default:
4369 gold_unreachable();
4370 }
4371 }
4372
4373 // Return alignment of an instruction template.
4374
4375 unsigned
4376 Insn_template::alignment() const
4377 {
4378 switch (this->type())
4379 {
4380 case THUMB16_TYPE:
4381 case THUMB16_SPECIAL_TYPE:
4382 case THUMB32_TYPE:
4383 return 2;
4384 case ARM_TYPE:
4385 case DATA_TYPE:
4386 return 4;
4387 default:
4388 gold_unreachable();
4389 }
4390 }
4391
4392 // Stub_template methods.
4393
4394 Stub_template::Stub_template(
4395 Stub_type type, const Insn_template* insns,
4396 size_t insn_count)
4397 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4398 entry_in_thumb_mode_(false), relocs_()
4399 {
4400 off_t offset = 0;
4401
4402 // Compute byte size and alignment of stub template.
4403 for (size_t i = 0; i < insn_count; i++)
4404 {
4405 unsigned insn_alignment = insns[i].alignment();
4406 size_t insn_size = insns[i].size();
4407 gold_assert((offset & (insn_alignment - 1)) == 0);
4408 this->alignment_ = std::max(this->alignment_, insn_alignment);
4409 switch (insns[i].type())
4410 {
4411 case Insn_template::THUMB16_TYPE:
4412 case Insn_template::THUMB16_SPECIAL_TYPE:
4413 if (i == 0)
4414 this->entry_in_thumb_mode_ = true;
4415 break;
4416
4417 case Insn_template::THUMB32_TYPE:
4418 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4419 this->relocs_.push_back(Reloc(i, offset));
4420 if (i == 0)
4421 this->entry_in_thumb_mode_ = true;
4422 break;
4423
4424 case Insn_template::ARM_TYPE:
4425 // Handle cases where the target is encoded within the
4426 // instruction.
4427 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4428 this->relocs_.push_back(Reloc(i, offset));
4429 break;
4430
4431 case Insn_template::DATA_TYPE:
4432 // Entry point cannot be data.
4433 gold_assert(i != 0);
4434 this->relocs_.push_back(Reloc(i, offset));
4435 break;
4436
4437 default:
4438 gold_unreachable();
4439 }
4440 offset += insn_size;
4441 }
4442 this->size_ = offset;
4443 }
4444
4445 // Stub methods.
4446
4447 // Template to implement do_write for a specific target endianness.
4448
4449 template<bool big_endian>
4450 void inline
4451 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4452 {
4453 const Stub_template* stub_template = this->stub_template();
4454 const Insn_template* insns = stub_template->insns();
4455
4456 // FIXME: We do not handle BE8 encoding yet.
4457 unsigned char* pov = view;
4458 for (size_t i = 0; i < stub_template->insn_count(); i++)
4459 {
4460 switch (insns[i].type())
4461 {
4462 case Insn_template::THUMB16_TYPE:
4463 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4464 break;
4465 case Insn_template::THUMB16_SPECIAL_TYPE:
4466 elfcpp::Swap<16, big_endian>::writeval(
4467 pov,
4468 this->thumb16_special(i));
4469 break;
4470 case Insn_template::THUMB32_TYPE:
4471 {
4472 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4473 uint32_t lo = insns[i].data() & 0xffff;
4474 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4475 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4476 }
4477 break;
4478 case Insn_template::ARM_TYPE:
4479 case Insn_template::DATA_TYPE:
4480 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4481 break;
4482 default:
4483 gold_unreachable();
4484 }
4485 pov += insns[i].size();
4486 }
4487 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4488 }
4489
4490 // Reloc_stub::Key methods.
4491
4492 // Dump a Key as a string for debugging.
4493
4494 std::string
4495 Reloc_stub::Key::name() const
4496 {
4497 if (this->r_sym_ == invalid_index)
4498 {
4499 // Global symbol key name
4500 // <stub-type>:<symbol name>:<addend>.
4501 const std::string sym_name = this->u_.symbol->name();
4502 // We need to print two hex number and two colons. So just add 100 bytes
4503 // to the symbol name size.
4504 size_t len = sym_name.size() + 100;
4505 char* buffer = new char[len];
4506 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4507 sym_name.c_str(), this->addend_);
4508 gold_assert(c > 0 && c < static_cast<int>(len));
4509 delete[] buffer;
4510 return std::string(buffer);
4511 }
4512 else
4513 {
4514 // local symbol key name
4515 // <stub-type>:<object>:<r_sym>:<addend>.
4516 const size_t len = 200;
4517 char buffer[len];
4518 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4519 this->u_.relobj, this->r_sym_, this->addend_);
4520 gold_assert(c > 0 && c < static_cast<int>(len));
4521 return std::string(buffer);
4522 }
4523 }
4524
4525 // Reloc_stub methods.
4526
4527 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4528 // LOCATION to DESTINATION.
4529 // This code is based on the arm_type_of_stub function in
4530 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4531 // class simple.
4532
4533 Stub_type
4534 Reloc_stub::stub_type_for_reloc(
4535 unsigned int r_type,
4536 Arm_address location,
4537 Arm_address destination,
4538 bool target_is_thumb)
4539 {
4540 Stub_type stub_type = arm_stub_none;
4541
4542 // This is a bit ugly but we want to avoid using a templated class for
4543 // big and little endianities.
4544 bool may_use_blx;
4545 bool should_force_pic_veneer = parameters->options().pic_veneer();
4546 bool thumb2;
4547 bool thumb_only;
4548 if (parameters->target().is_big_endian())
4549 {
4550 const Target_arm<true>* big_endian_target =
4551 Target_arm<true>::default_target();
4552 may_use_blx = big_endian_target->may_use_v5t_interworking();
4553 should_force_pic_veneer |= big_endian_target->should_force_pic_veneer();
4554 thumb2 = big_endian_target->using_thumb2();
4555 thumb_only = big_endian_target->using_thumb_only();
4556 }
4557 else
4558 {
4559 const Target_arm<false>* little_endian_target =
4560 Target_arm<false>::default_target();
4561 may_use_blx = little_endian_target->may_use_v5t_interworking();
4562 should_force_pic_veneer |=
4563 little_endian_target->should_force_pic_veneer();
4564 thumb2 = little_endian_target->using_thumb2();
4565 thumb_only = little_endian_target->using_thumb_only();
4566 }
4567
4568 int64_t branch_offset;
4569 bool output_is_position_independent =
4570 parameters->options().output_is_position_independent();
4571 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4572 {
4573 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4574 // base address (instruction address + 4).
4575 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4576 destination = Bits<32>::bit_select32(destination, location, 0x2);
4577 branch_offset = static_cast<int64_t>(destination) - location;
4578
4579 // Handle cases where:
4580 // - this call goes too far (different Thumb/Thumb2 max
4581 // distance)
4582 // - it's a Thumb->Arm call and blx is not available, or it's a
4583 // Thumb->Arm branch (not bl). A stub is needed in this case.
4584 if ((!thumb2
4585 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4586 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4587 || (thumb2
4588 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4589 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4590 || ((!target_is_thumb)
4591 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4592 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4593 {
4594 if (target_is_thumb)
4595 {
4596 // Thumb to thumb.
4597 if (!thumb_only)
4598 {
4599 stub_type = (output_is_position_independent
4600 || should_force_pic_veneer)
4601 // PIC stubs.
4602 ? ((may_use_blx
4603 && (r_type == elfcpp::R_ARM_THM_CALL))
4604 // V5T and above. Stub starts with ARM code, so
4605 // we must be able to switch mode before
4606 // reaching it, which is only possible for 'bl'
4607 // (ie R_ARM_THM_CALL relocation).
4608 ? arm_stub_long_branch_any_thumb_pic
4609 // On V4T, use Thumb code only.
4610 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4611
4612 // non-PIC stubs.
4613 : ((may_use_blx
4614 && (r_type == elfcpp::R_ARM_THM_CALL))
4615 ? arm_stub_long_branch_any_any // V5T and above.
4616 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4617 }
4618 else
4619 {
4620 stub_type = (output_is_position_independent
4621 || should_force_pic_veneer)
4622 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4623 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4624 }
4625 }
4626 else
4627 {
4628 // Thumb to arm.
4629
4630 // FIXME: We should check that the input section is from an
4631 // object that has interwork enabled.
4632
4633 stub_type = (output_is_position_independent
4634 || should_force_pic_veneer)
4635 // PIC stubs.
4636 ? ((may_use_blx
4637 && (r_type == elfcpp::R_ARM_THM_CALL))
4638 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4639 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4640
4641 // non-PIC stubs.
4642 : ((may_use_blx
4643 && (r_type == elfcpp::R_ARM_THM_CALL))
4644 ? arm_stub_long_branch_any_any // V5T and above.
4645 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4646
4647 // Handle v4t short branches.
4648 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4649 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4650 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4651 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4652 }
4653 }
4654 }
4655 else if (r_type == elfcpp::R_ARM_CALL
4656 || r_type == elfcpp::R_ARM_JUMP24
4657 || r_type == elfcpp::R_ARM_PLT32)
4658 {
4659 branch_offset = static_cast<int64_t>(destination) - location;
4660 if (target_is_thumb)
4661 {
4662 // Arm to thumb.
4663
4664 // FIXME: We should check that the input section is from an
4665 // object that has interwork enabled.
4666
4667 // We have an extra 2-bytes reach because of
4668 // the mode change (bit 24 (H) of BLX encoding).
4669 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4670 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4671 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4672 || (r_type == elfcpp::R_ARM_JUMP24)
4673 || (r_type == elfcpp::R_ARM_PLT32))
4674 {
4675 stub_type = (output_is_position_independent
4676 || should_force_pic_veneer)
4677 // PIC stubs.
4678 ? (may_use_blx
4679 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4680 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4681
4682 // non-PIC stubs.
4683 : (may_use_blx
4684 ? arm_stub_long_branch_any_any // V5T and above.
4685 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4686 }
4687 }
4688 else
4689 {
4690 // Arm to arm.
4691 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4692 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4693 {
4694 stub_type = (output_is_position_independent
4695 || should_force_pic_veneer)
4696 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4697 : arm_stub_long_branch_any_any; /// non-PIC.
4698 }
4699 }
4700 }
4701
4702 return stub_type;
4703 }
4704
4705 // Cortex_a8_stub methods.
4706
4707 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4708 // I is the position of the instruction template in the stub template.
4709
4710 uint16_t
4711 Cortex_a8_stub::do_thumb16_special(size_t i)
4712 {
4713 // The only use of this is to copy condition code from a conditional
4714 // branch being worked around to the corresponding conditional branch in
4715 // to the stub.
4716 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4717 && i == 0);
4718 uint16_t data = this->stub_template()->insns()[i].data();
4719 gold_assert((data & 0xff00U) == 0xd000U);
4720 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4721 return data;
4722 }
4723
4724 // Stub_factory methods.
4725
4726 Stub_factory::Stub_factory()
4727 {
4728 // The instruction template sequences are declared as static
4729 // objects and initialized first time the constructor runs.
4730
4731 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4732 // to reach the stub if necessary.
4733 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4734 {
4735 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4736 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4737 // dcd R_ARM_ABS32(X)
4738 };
4739
4740 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4741 // available.
4742 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4743 {
4744 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4745 Insn_template::arm_insn(0xe12fff1c), // bx ip
4746 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4747 // dcd R_ARM_ABS32(X)
4748 };
4749
4750 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4751 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4752 {
4753 Insn_template::thumb16_insn(0xb401), // push {r0}
4754 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4755 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4756 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4757 Insn_template::thumb16_insn(0x4760), // bx ip
4758 Insn_template::thumb16_insn(0xbf00), // nop
4759 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4760 // dcd R_ARM_ABS32(X)
4761 };
4762
4763 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4764 // allowed.
4765 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4766 {
4767 Insn_template::thumb16_insn(0x4778), // bx pc
4768 Insn_template::thumb16_insn(0x46c0), // nop
4769 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4770 Insn_template::arm_insn(0xe12fff1c), // bx ip
4771 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4772 // dcd R_ARM_ABS32(X)
4773 };
4774
4775 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4776 // available.
4777 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4778 {
4779 Insn_template::thumb16_insn(0x4778), // bx pc
4780 Insn_template::thumb16_insn(0x46c0), // nop
4781 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4782 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4783 // dcd R_ARM_ABS32(X)
4784 };
4785
4786 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4787 // one, when the destination is close enough.
4788 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4789 {
4790 Insn_template::thumb16_insn(0x4778), // bx pc
4791 Insn_template::thumb16_insn(0x46c0), // nop
4792 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4793 };
4794
4795 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4796 // blx to reach the stub if necessary.
4797 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4798 {
4799 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4800 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4801 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4802 // dcd R_ARM_REL32(X-4)
4803 };
4804
4805 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4806 // blx to reach the stub if necessary. We can not add into pc;
4807 // it is not guaranteed to mode switch (different in ARMv6 and
4808 // ARMv7).
4809 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4810 {
4811 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4812 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4813 Insn_template::arm_insn(0xe12fff1c), // bx ip
4814 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4815 // dcd R_ARM_REL32(X)
4816 };
4817
4818 // V4T ARM -> ARM long branch stub, PIC.
4819 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4820 {
4821 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4822 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4823 Insn_template::arm_insn(0xe12fff1c), // bx ip
4824 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4825 // dcd R_ARM_REL32(X)
4826 };
4827
4828 // V4T Thumb -> ARM long branch stub, PIC.
4829 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4830 {
4831 Insn_template::thumb16_insn(0x4778), // bx pc
4832 Insn_template::thumb16_insn(0x46c0), // nop
4833 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4834 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4835 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4836 // dcd R_ARM_REL32(X)
4837 };
4838
4839 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4840 // architectures.
4841 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4842 {
4843 Insn_template::thumb16_insn(0xb401), // push {r0}
4844 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4845 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4846 Insn_template::thumb16_insn(0x4484), // add ip, r0
4847 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4848 Insn_template::thumb16_insn(0x4760), // bx ip
4849 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4850 // dcd R_ARM_REL32(X)
4851 };
4852
4853 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4854 // allowed.
4855 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4856 {
4857 Insn_template::thumb16_insn(0x4778), // bx pc
4858 Insn_template::thumb16_insn(0x46c0), // nop
4859 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4860 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4861 Insn_template::arm_insn(0xe12fff1c), // bx ip
4862 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4863 // dcd R_ARM_REL32(X)
4864 };
4865
4866 // Cortex-A8 erratum-workaround stubs.
4867
4868 // Stub used for conditional branches (which may be beyond +/-1MB away,
4869 // so we can't use a conditional branch to reach this stub).
4870
4871 // original code:
4872 //
4873 // b<cond> X
4874 // after:
4875 //
4876 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4877 {
4878 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4879 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4880 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4881 // b.w X
4882 };
4883
4884 // Stub used for b.w and bl.w instructions.
4885
4886 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4887 {
4888 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4889 };
4890
4891 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4892 {
4893 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4894 };
4895
4896 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4897 // instruction (which switches to ARM mode) to point to this stub. Jump to
4898 // the real destination using an ARM-mode branch.
4899 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4900 {
4901 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4902 };
4903
4904 // Stub used to provide an interworking for R_ARM_V4BX relocation
4905 // (bx r[n] instruction).
4906 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4907 {
4908 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4909 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4910 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4911 };
4912
4913 // Fill in the stub template look-up table. Stub templates are constructed
4914 // per instance of Stub_factory for fast look-up without locking
4915 // in a thread-enabled environment.
4916
4917 this->stub_templates_[arm_stub_none] =
4918 new Stub_template(arm_stub_none, NULL, 0);
4919
4920 #define DEF_STUB(x) \
4921 do \
4922 { \
4923 size_t array_size \
4924 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4925 Stub_type type = arm_stub_##x; \
4926 this->stub_templates_[type] = \
4927 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4928 } \
4929 while (0);
4930
4931 DEF_STUBS
4932 #undef DEF_STUB
4933 }
4934
4935 // Stub_table methods.
4936
4937 // Remove all Cortex-A8 stub.
4938
4939 template<bool big_endian>
4940 void
4941 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4942 {
4943 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4944 p != this->cortex_a8_stubs_.end();
4945 ++p)
4946 delete p->second;
4947 this->cortex_a8_stubs_.clear();
4948 }
4949
4950 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4951
4952 template<bool big_endian>
4953 void
4954 Stub_table<big_endian>::relocate_stub(
4955 Stub* stub,
4956 const Relocate_info<32, big_endian>* relinfo,
4957 Target_arm<big_endian>* arm_target,
4958 Output_section* output_section,
4959 unsigned char* view,
4960 Arm_address address,
4961 section_size_type view_size)
4962 {
4963 const Stub_template* stub_template = stub->stub_template();
4964 if (stub_template->reloc_count() != 0)
4965 {
4966 // Adjust view to cover the stub only.
4967 section_size_type offset = stub->offset();
4968 section_size_type stub_size = stub_template->size();
4969 gold_assert(offset + stub_size <= view_size);
4970
4971 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4972 address + offset, stub_size);
4973 }
4974 }
4975
4976 // Relocate all stubs in this stub table.
4977
4978 template<bool big_endian>
4979 void
4980 Stub_table<big_endian>::relocate_stubs(
4981 const Relocate_info<32, big_endian>* relinfo,
4982 Target_arm<big_endian>* arm_target,
4983 Output_section* output_section,
4984 unsigned char* view,
4985 Arm_address address,
4986 section_size_type view_size)
4987 {
4988 // If we are passed a view bigger than the stub table's. we need to
4989 // adjust the view.
4990 gold_assert(address == this->address()
4991 && (view_size
4992 == static_cast<section_size_type>(this->data_size())));
4993
4994 // Relocate all relocation stubs.
4995 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4996 p != this->reloc_stubs_.end();
4997 ++p)
4998 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4999 address, view_size);
5000
5001 // Relocate all Cortex-A8 stubs.
5002 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
5003 p != this->cortex_a8_stubs_.end();
5004 ++p)
5005 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5006 address, view_size);
5007
5008 // Relocate all ARM V4BX stubs.
5009 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
5010 p != this->arm_v4bx_stubs_.end();
5011 ++p)
5012 {
5013 if (*p != NULL)
5014 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
5015 address, view_size);
5016 }
5017 }
5018
5019 // Write out the stubs to file.
5020
5021 template<bool big_endian>
5022 void
5023 Stub_table<big_endian>::do_write(Output_file* of)
5024 {
5025 off_t offset = this->offset();
5026 const section_size_type oview_size =
5027 convert_to_section_size_type(this->data_size());
5028 unsigned char* const oview = of->get_output_view(offset, oview_size);
5029
5030 // Write relocation stubs.
5031 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
5032 p != this->reloc_stubs_.end();
5033 ++p)
5034 {
5035 Reloc_stub* stub = p->second;
5036 Arm_address address = this->address() + stub->offset();
5037 gold_assert(address
5038 == align_address(address,
5039 stub->stub_template()->alignment()));
5040 stub->write(oview + stub->offset(), stub->stub_template()->size(),
5041 big_endian);
5042 }
5043
5044 // Write Cortex-A8 stubs.
5045 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5046 p != this->cortex_a8_stubs_.end();
5047 ++p)
5048 {
5049 Cortex_a8_stub* stub = p->second;
5050 Arm_address address = this->address() + stub->offset();
5051 gold_assert(address
5052 == align_address(address,
5053 stub->stub_template()->alignment()));
5054 stub->write(oview + stub->offset(), stub->stub_template()->size(),
5055 big_endian);
5056 }
5057
5058 // Write ARM V4BX relocation stubs.
5059 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5060 p != this->arm_v4bx_stubs_.end();
5061 ++p)
5062 {
5063 if (*p == NULL)
5064 continue;
5065
5066 Arm_address address = this->address() + (*p)->offset();
5067 gold_assert(address
5068 == align_address(address,
5069 (*p)->stub_template()->alignment()));
5070 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
5071 big_endian);
5072 }
5073
5074 of->write_output_view(this->offset(), oview_size, oview);
5075 }
5076
5077 // Update the data size and address alignment of the stub table at the end
5078 // of a relaxation pass. Return true if either the data size or the
5079 // alignment changed in this relaxation pass.
5080
5081 template<bool big_endian>
5082 bool
5083 Stub_table<big_endian>::update_data_size_and_addralign()
5084 {
5085 // Go over all stubs in table to compute data size and address alignment.
5086 off_t size = this->reloc_stubs_size_;
5087 unsigned addralign = this->reloc_stubs_addralign_;
5088
5089 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5090 p != this->cortex_a8_stubs_.end();
5091 ++p)
5092 {
5093 const Stub_template* stub_template = p->second->stub_template();
5094 addralign = std::max(addralign, stub_template->alignment());
5095 size = (align_address(size, stub_template->alignment())
5096 + stub_template->size());
5097 }
5098
5099 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5100 p != this->arm_v4bx_stubs_.end();
5101 ++p)
5102 {
5103 if (*p == NULL)
5104 continue;
5105
5106 const Stub_template* stub_template = (*p)->stub_template();
5107 addralign = std::max(addralign, stub_template->alignment());
5108 size = (align_address(size, stub_template->alignment())
5109 + stub_template->size());
5110 }
5111
5112 // Check if either data size or alignment changed in this pass.
5113 // Update prev_data_size_ and prev_addralign_. These will be used
5114 // as the current data size and address alignment for the next pass.
5115 bool changed = size != this->prev_data_size_;
5116 this->prev_data_size_ = size;
5117
5118 if (addralign != this->prev_addralign_)
5119 changed = true;
5120 this->prev_addralign_ = addralign;
5121
5122 return changed;
5123 }
5124
5125 // Finalize the stubs. This sets the offsets of the stubs within the stub
5126 // table. It also marks all input sections needing Cortex-A8 workaround.
5127
5128 template<bool big_endian>
5129 void
5130 Stub_table<big_endian>::finalize_stubs()
5131 {
5132 off_t off = this->reloc_stubs_size_;
5133 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5134 p != this->cortex_a8_stubs_.end();
5135 ++p)
5136 {
5137 Cortex_a8_stub* stub = p->second;
5138 const Stub_template* stub_template = stub->stub_template();
5139 uint64_t stub_addralign = stub_template->alignment();
5140 off = align_address(off, stub_addralign);
5141 stub->set_offset(off);
5142 off += stub_template->size();
5143
5144 // Mark input section so that we can determine later if a code section
5145 // needs the Cortex-A8 workaround quickly.
5146 Arm_relobj<big_endian>* arm_relobj =
5147 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5148 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5149 }
5150
5151 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5152 p != this->arm_v4bx_stubs_.end();
5153 ++p)
5154 {
5155 if (*p == NULL)
5156 continue;
5157
5158 const Stub_template* stub_template = (*p)->stub_template();
5159 uint64_t stub_addralign = stub_template->alignment();
5160 off = align_address(off, stub_addralign);
5161 (*p)->set_offset(off);
5162 off += stub_template->size();
5163 }
5164
5165 gold_assert(off <= this->prev_data_size_);
5166 }
5167
5168 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5169 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5170 // of the address range seen by the linker.
5171
5172 template<bool big_endian>
5173 void
5174 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5175 Target_arm<big_endian>* arm_target,
5176 unsigned char* view,
5177 Arm_address view_address,
5178 section_size_type view_size)
5179 {
5180 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5181 for (Cortex_a8_stub_list::const_iterator p =
5182 this->cortex_a8_stubs_.lower_bound(view_address);
5183 ((p != this->cortex_a8_stubs_.end())
5184 && (p->first < (view_address + view_size)));
5185 ++p)
5186 {
5187 // We do not store the THUMB bit in the LSB of either the branch address
5188 // or the stub offset. There is no need to strip the LSB.
5189 Arm_address branch_address = p->first;
5190 const Cortex_a8_stub* stub = p->second;
5191 Arm_address stub_address = this->address() + stub->offset();
5192
5193 // Offset of the branch instruction relative to this view.
5194 section_size_type offset =
5195 convert_to_section_size_type(branch_address - view_address);
5196 gold_assert((offset + 4) <= view_size);
5197
5198 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5199 view + offset, branch_address);
5200 }
5201 }
5202
5203 // Arm_input_section methods.
5204
5205 // Initialize an Arm_input_section.
5206
5207 template<bool big_endian>
5208 void
5209 Arm_input_section<big_endian>::init()
5210 {
5211 Relobj* relobj = this->relobj();
5212 unsigned int shndx = this->shndx();
5213
5214 // We have to cache original size, alignment and contents to avoid locking
5215 // the original file.
5216 this->original_addralign_ =
5217 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5218
5219 // This is not efficient but we expect only a small number of relaxed
5220 // input sections for stubs.
5221 section_size_type section_size;
5222 const unsigned char* section_contents =
5223 relobj->section_contents(shndx, &section_size, false);
5224 this->original_size_ =
5225 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5226
5227 gold_assert(this->original_contents_ == NULL);
5228 this->original_contents_ = new unsigned char[section_size];
5229 memcpy(this->original_contents_, section_contents, section_size);
5230
5231 // We want to make this look like the original input section after
5232 // output sections are finalized.
5233 Output_section* os = relobj->output_section(shndx);
5234 off_t offset = relobj->output_section_offset(shndx);
5235 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5236 this->set_address(os->address() + offset);
5237 this->set_file_offset(os->offset() + offset);
5238
5239 this->set_current_data_size(this->original_size_);
5240 this->finalize_data_size();
5241 }
5242
5243 template<bool big_endian>
5244 void
5245 Arm_input_section<big_endian>::do_write(Output_file* of)
5246 {
5247 // We have to write out the original section content.
5248 gold_assert(this->original_contents_ != NULL);
5249 of->write(this->offset(), this->original_contents_,
5250 this->original_size_);
5251
5252 // If this owns a stub table and it is not empty, write it.
5253 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5254 this->stub_table_->write(of);
5255 }
5256
5257 // Finalize data size.
5258
5259 template<bool big_endian>
5260 void
5261 Arm_input_section<big_endian>::set_final_data_size()
5262 {
5263 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5264
5265 if (this->is_stub_table_owner())
5266 {
5267 this->stub_table_->finalize_data_size();
5268 off = align_address(off, this->stub_table_->addralign());
5269 off += this->stub_table_->data_size();
5270 }
5271 this->set_data_size(off);
5272 }
5273
5274 // Reset address and file offset.
5275
5276 template<bool big_endian>
5277 void
5278 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5279 {
5280 // Size of the original input section contents.
5281 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5282
5283 // If this is a stub table owner, account for the stub table size.
5284 if (this->is_stub_table_owner())
5285 {
5286 Stub_table<big_endian>* stub_table = this->stub_table_;
5287
5288 // Reset the stub table's address and file offset. The
5289 // current data size for child will be updated after that.
5290 stub_table_->reset_address_and_file_offset();
5291 off = align_address(off, stub_table_->addralign());
5292 off += stub_table->current_data_size();
5293 }
5294
5295 this->set_current_data_size(off);
5296 }
5297
5298 // Arm_exidx_cantunwind methods.
5299
5300 // Write this to Output file OF for a fixed endianness.
5301
5302 template<bool big_endian>
5303 void
5304 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5305 {
5306 off_t offset = this->offset();
5307 const section_size_type oview_size = 8;
5308 unsigned char* const oview = of->get_output_view(offset, oview_size);
5309
5310 Output_section* os = this->relobj_->output_section(this->shndx_);
5311 gold_assert(os != NULL);
5312
5313 Arm_relobj<big_endian>* arm_relobj =
5314 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5315 Arm_address output_offset =
5316 arm_relobj->get_output_section_offset(this->shndx_);
5317 Arm_address section_start;
5318 section_size_type section_size;
5319
5320 // Find out the end of the text section referred by this.
5321 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5322 {
5323 section_start = os->address() + output_offset;
5324 const Arm_exidx_input_section* exidx_input_section =
5325 arm_relobj->exidx_input_section_by_link(this->shndx_);
5326 gold_assert(exidx_input_section != NULL);
5327 section_size =
5328 convert_to_section_size_type(exidx_input_section->text_size());
5329 }
5330 else
5331 {
5332 // Currently this only happens for a relaxed section.
5333 const Output_relaxed_input_section* poris =
5334 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5335 gold_assert(poris != NULL);
5336 section_start = poris->address();
5337 section_size = convert_to_section_size_type(poris->data_size());
5338 }
5339
5340 // We always append this to the end of an EXIDX section.
5341 Arm_address output_address = section_start + section_size;
5342
5343 // Write out the entry. The first word either points to the beginning
5344 // or after the end of a text section. The second word is the special
5345 // EXIDX_CANTUNWIND value.
5346 uint32_t prel31_offset = output_address - this->address();
5347 if (Bits<31>::has_overflow32(offset))
5348 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5349 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5350 prel31_offset & 0x7fffffffU);
5351 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5352 elfcpp::EXIDX_CANTUNWIND);
5353
5354 of->write_output_view(this->offset(), oview_size, oview);
5355 }
5356
5357 // Arm_exidx_merged_section methods.
5358
5359 // Constructor for Arm_exidx_merged_section.
5360 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5361 // SECTION_OFFSET_MAP points to a section offset map describing how
5362 // parts of the input section are mapped to output. DELETED_BYTES is
5363 // the number of bytes deleted from the EXIDX input section.
5364
5365 Arm_exidx_merged_section::Arm_exidx_merged_section(
5366 const Arm_exidx_input_section& exidx_input_section,
5367 const Arm_exidx_section_offset_map& section_offset_map,
5368 uint32_t deleted_bytes)
5369 : Output_relaxed_input_section(exidx_input_section.relobj(),
5370 exidx_input_section.shndx(),
5371 exidx_input_section.addralign()),
5372 exidx_input_section_(exidx_input_section),
5373 section_offset_map_(section_offset_map)
5374 {
5375 // If we retain or discard the whole EXIDX input section, we would
5376 // not be here.
5377 gold_assert(deleted_bytes != 0
5378 && deleted_bytes != this->exidx_input_section_.size());
5379
5380 // Fix size here so that we do not need to implement set_final_data_size.
5381 uint32_t size = exidx_input_section.size() - deleted_bytes;
5382 this->set_data_size(size);
5383 this->fix_data_size();
5384
5385 // Allocate buffer for section contents and build contents.
5386 this->section_contents_ = new unsigned char[size];
5387 }
5388
5389 // Build the contents of a merged EXIDX output section.
5390
5391 void
5392 Arm_exidx_merged_section::build_contents(
5393 const unsigned char* original_contents,
5394 section_size_type original_size)
5395 {
5396 // Go over spans of input offsets and write only those that are not
5397 // discarded.
5398 section_offset_type in_start = 0;
5399 section_offset_type out_start = 0;
5400 section_offset_type in_max =
5401 convert_types<section_offset_type>(original_size);
5402 section_offset_type out_max =
5403 convert_types<section_offset_type>(this->data_size());
5404 for (Arm_exidx_section_offset_map::const_iterator p =
5405 this->section_offset_map_.begin();
5406 p != this->section_offset_map_.end();
5407 ++p)
5408 {
5409 section_offset_type in_end = p->first;
5410 gold_assert(in_end >= in_start);
5411 section_offset_type out_end = p->second;
5412 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5413 if (out_end != -1)
5414 {
5415 size_t out_chunk_size =
5416 convert_types<size_t>(out_end - out_start + 1);
5417
5418 gold_assert(out_chunk_size == in_chunk_size
5419 && in_end < in_max && out_end < out_max);
5420
5421 memcpy(this->section_contents_ + out_start,
5422 original_contents + in_start,
5423 out_chunk_size);
5424 out_start += out_chunk_size;
5425 }
5426 in_start += in_chunk_size;
5427 }
5428 }
5429
5430 // Given an input OBJECT, an input section index SHNDX within that
5431 // object, and an OFFSET relative to the start of that input
5432 // section, return whether or not the corresponding offset within
5433 // the output section is known. If this function returns true, it
5434 // sets *POUTPUT to the output offset. The value -1 indicates that
5435 // this input offset is being discarded.
5436
5437 bool
5438 Arm_exidx_merged_section::do_output_offset(
5439 const Relobj* relobj,
5440 unsigned int shndx,
5441 section_offset_type offset,
5442 section_offset_type* poutput) const
5443 {
5444 // We only handle offsets for the original EXIDX input section.
5445 if (relobj != this->exidx_input_section_.relobj()
5446 || shndx != this->exidx_input_section_.shndx())
5447 return false;
5448
5449 section_offset_type section_size =
5450 convert_types<section_offset_type>(this->exidx_input_section_.size());
5451 if (offset < 0 || offset >= section_size)
5452 // Input offset is out of valid range.
5453 *poutput = -1;
5454 else
5455 {
5456 // We need to look up the section offset map to determine the output
5457 // offset. Find the reference point in map that is first offset
5458 // bigger than or equal to this offset.
5459 Arm_exidx_section_offset_map::const_iterator p =
5460 this->section_offset_map_.lower_bound(offset);
5461
5462 // The section offset maps are build such that this should not happen if
5463 // input offset is in the valid range.
5464 gold_assert(p != this->section_offset_map_.end());
5465
5466 // We need to check if this is dropped.
5467 section_offset_type ref = p->first;
5468 section_offset_type mapped_ref = p->second;
5469
5470 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5471 // Offset is present in output.
5472 *poutput = mapped_ref + (offset - ref);
5473 else
5474 // Offset is discarded owing to EXIDX entry merging.
5475 *poutput = -1;
5476 }
5477
5478 return true;
5479 }
5480
5481 // Write this to output file OF.
5482
5483 void
5484 Arm_exidx_merged_section::do_write(Output_file* of)
5485 {
5486 off_t offset = this->offset();
5487 const section_size_type oview_size = this->data_size();
5488 unsigned char* const oview = of->get_output_view(offset, oview_size);
5489
5490 Output_section* os = this->relobj()->output_section(this->shndx());
5491 gold_assert(os != NULL);
5492
5493 memcpy(oview, this->section_contents_, oview_size);
5494 of->write_output_view(this->offset(), oview_size, oview);
5495 }
5496
5497 // Arm_exidx_fixup methods.
5498
5499 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5500 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5501 // points to the end of the last seen EXIDX section.
5502
5503 void
5504 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5505 {
5506 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5507 && this->last_input_section_ != NULL)
5508 {
5509 Relobj* relobj = this->last_input_section_->relobj();
5510 unsigned int text_shndx = this->last_input_section_->link();
5511 Arm_exidx_cantunwind* cantunwind =
5512 new Arm_exidx_cantunwind(relobj, text_shndx);
5513 this->exidx_output_section_->add_output_section_data(cantunwind);
5514 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5515 }
5516 }
5517
5518 // Process an EXIDX section entry in input. Return whether this entry
5519 // can be deleted in the output. SECOND_WORD in the second word of the
5520 // EXIDX entry.
5521
5522 bool
5523 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5524 {
5525 bool delete_entry;
5526 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5527 {
5528 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5529 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5530 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5531 }
5532 else if ((second_word & 0x80000000) != 0)
5533 {
5534 // Inlined unwinding data. Merge if equal to previous.
5535 delete_entry = (merge_exidx_entries_
5536 && this->last_unwind_type_ == UT_INLINED_ENTRY
5537 && this->last_inlined_entry_ == second_word);
5538 this->last_unwind_type_ = UT_INLINED_ENTRY;
5539 this->last_inlined_entry_ = second_word;
5540 }
5541 else
5542 {
5543 // Normal table entry. In theory we could merge these too,
5544 // but duplicate entries are likely to be much less common.
5545 delete_entry = false;
5546 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5547 }
5548 return delete_entry;
5549 }
5550
5551 // Update the current section offset map during EXIDX section fix-up.
5552 // If there is no map, create one. INPUT_OFFSET is the offset of a
5553 // reference point, DELETED_BYTES is the number of deleted by in the
5554 // section so far. If DELETE_ENTRY is true, the reference point and
5555 // all offsets after the previous reference point are discarded.
5556
5557 void
5558 Arm_exidx_fixup::update_offset_map(
5559 section_offset_type input_offset,
5560 section_size_type deleted_bytes,
5561 bool delete_entry)
5562 {
5563 if (this->section_offset_map_ == NULL)
5564 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5565 section_offset_type output_offset;
5566 if (delete_entry)
5567 output_offset = Arm_exidx_input_section::invalid_offset;
5568 else
5569 output_offset = input_offset - deleted_bytes;
5570 (*this->section_offset_map_)[input_offset] = output_offset;
5571 }
5572
5573 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5574 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5575 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5576 // If some entries are merged, also store a pointer to a newly created
5577 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5578 // owns the map and is responsible for releasing it after use.
5579
5580 template<bool big_endian>
5581 uint32_t
5582 Arm_exidx_fixup::process_exidx_section(
5583 const Arm_exidx_input_section* exidx_input_section,
5584 const unsigned char* section_contents,
5585 section_size_type section_size,
5586 Arm_exidx_section_offset_map** psection_offset_map)
5587 {
5588 Relobj* relobj = exidx_input_section->relobj();
5589 unsigned shndx = exidx_input_section->shndx();
5590
5591 if ((section_size % 8) != 0)
5592 {
5593 // Something is wrong with this section. Better not touch it.
5594 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5595 relobj->name().c_str(), shndx);
5596 this->last_input_section_ = exidx_input_section;
5597 this->last_unwind_type_ = UT_NONE;
5598 return 0;
5599 }
5600
5601 uint32_t deleted_bytes = 0;
5602 bool prev_delete_entry = false;
5603 gold_assert(this->section_offset_map_ == NULL);
5604
5605 for (section_size_type i = 0; i < section_size; i += 8)
5606 {
5607 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5608 const Valtype* wv =
5609 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5610 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5611
5612 bool delete_entry = this->process_exidx_entry(second_word);
5613
5614 // Entry deletion causes changes in output offsets. We use a std::map
5615 // to record these. And entry (x, y) means input offset x
5616 // is mapped to output offset y. If y is invalid_offset, then x is
5617 // dropped in the output. Because of the way std::map::lower_bound
5618 // works, we record the last offset in a region w.r.t to keeping or
5619 // dropping. If there is no entry (x0, y0) for an input offset x0,
5620 // the output offset y0 of it is determined by the output offset y1 of
5621 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5622 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5623 // y0 is also -1.
5624 if (delete_entry != prev_delete_entry && i != 0)
5625 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5626
5627 // Update total deleted bytes for this entry.
5628 if (delete_entry)
5629 deleted_bytes += 8;
5630
5631 prev_delete_entry = delete_entry;
5632 }
5633
5634 // If section offset map is not NULL, make an entry for the end of
5635 // section.
5636 if (this->section_offset_map_ != NULL)
5637 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5638
5639 *psection_offset_map = this->section_offset_map_;
5640 this->section_offset_map_ = NULL;
5641 this->last_input_section_ = exidx_input_section;
5642
5643 // Set the first output text section so that we can link the EXIDX output
5644 // section to it. Ignore any EXIDX input section that is completely merged.
5645 if (this->first_output_text_section_ == NULL
5646 && deleted_bytes != section_size)
5647 {
5648 unsigned int link = exidx_input_section->link();
5649 Output_section* os = relobj->output_section(link);
5650 gold_assert(os != NULL);
5651 this->first_output_text_section_ = os;
5652 }
5653
5654 return deleted_bytes;
5655 }
5656
5657 // Arm_output_section methods.
5658
5659 // Create a stub group for input sections from BEGIN to END. OWNER
5660 // points to the input section to be the owner a new stub table.
5661
5662 template<bool big_endian>
5663 void
5664 Arm_output_section<big_endian>::create_stub_group(
5665 Input_section_list::const_iterator begin,
5666 Input_section_list::const_iterator end,
5667 Input_section_list::const_iterator owner,
5668 Target_arm<big_endian>* target,
5669 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5670 const Task* task)
5671 {
5672 // We use a different kind of relaxed section in an EXIDX section.
5673 // The static casting from Output_relaxed_input_section to
5674 // Arm_input_section is invalid in an EXIDX section. We are okay
5675 // because we should not be calling this for an EXIDX section.
5676 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5677
5678 // Currently we convert ordinary input sections into relaxed sections only
5679 // at this point but we may want to support creating relaxed input section
5680 // very early. So we check here to see if owner is already a relaxed
5681 // section.
5682
5683 Arm_input_section<big_endian>* arm_input_section;
5684 if (owner->is_relaxed_input_section())
5685 {
5686 arm_input_section =
5687 Arm_input_section<big_endian>::as_arm_input_section(
5688 owner->relaxed_input_section());
5689 }
5690 else
5691 {
5692 gold_assert(owner->is_input_section());
5693 // Create a new relaxed input section. We need to lock the original
5694 // file.
5695 Task_lock_obj<Object> tl(task, owner->relobj());
5696 arm_input_section =
5697 target->new_arm_input_section(owner->relobj(), owner->shndx());
5698 new_relaxed_sections->push_back(arm_input_section);
5699 }
5700
5701 // Create a stub table.
5702 Stub_table<big_endian>* stub_table =
5703 target->new_stub_table(arm_input_section);
5704
5705 arm_input_section->set_stub_table(stub_table);
5706
5707 Input_section_list::const_iterator p = begin;
5708 Input_section_list::const_iterator prev_p;
5709
5710 // Look for input sections or relaxed input sections in [begin ... end].
5711 do
5712 {
5713 if (p->is_input_section() || p->is_relaxed_input_section())
5714 {
5715 // The stub table information for input sections live
5716 // in their objects.
5717 Arm_relobj<big_endian>* arm_relobj =
5718 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5719 arm_relobj->set_stub_table(p->shndx(), stub_table);
5720 }
5721 prev_p = p++;
5722 }
5723 while (prev_p != end);
5724 }
5725
5726 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5727 // of stub groups. We grow a stub group by adding input section until the
5728 // size is just below GROUP_SIZE. The last input section will be converted
5729 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5730 // input section after the stub table, effectively double the group size.
5731 //
5732 // This is similar to the group_sections() function in elf32-arm.c but is
5733 // implemented differently.
5734
5735 template<bool big_endian>
5736 void
5737 Arm_output_section<big_endian>::group_sections(
5738 section_size_type group_size,
5739 bool stubs_always_after_branch,
5740 Target_arm<big_endian>* target,
5741 const Task* task)
5742 {
5743 // States for grouping.
5744 typedef enum
5745 {
5746 // No group is being built.
5747 NO_GROUP,
5748 // A group is being built but the stub table is not found yet.
5749 // We keep group a stub group until the size is just under GROUP_SIZE.
5750 // The last input section in the group will be used as the stub table.
5751 FINDING_STUB_SECTION,
5752 // A group is being built and we have already found a stub table.
5753 // We enter this state to grow a stub group by adding input section
5754 // after the stub table. This effectively doubles the group size.
5755 HAS_STUB_SECTION
5756 } State;
5757
5758 // Any newly created relaxed sections are stored here.
5759 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5760
5761 State state = NO_GROUP;
5762 section_size_type off = 0;
5763 section_size_type group_begin_offset = 0;
5764 section_size_type group_end_offset = 0;
5765 section_size_type stub_table_end_offset = 0;
5766 Input_section_list::const_iterator group_begin =
5767 this->input_sections().end();
5768 Input_section_list::const_iterator stub_table =
5769 this->input_sections().end();
5770 Input_section_list::const_iterator group_end = this->input_sections().end();
5771 for (Input_section_list::const_iterator p = this->input_sections().begin();
5772 p != this->input_sections().end();
5773 ++p)
5774 {
5775 section_size_type section_begin_offset =
5776 align_address(off, p->addralign());
5777 section_size_type section_end_offset =
5778 section_begin_offset + p->data_size();
5779
5780 // Check to see if we should group the previously seen sections.
5781 switch (state)
5782 {
5783 case NO_GROUP:
5784 break;
5785
5786 case FINDING_STUB_SECTION:
5787 // Adding this section makes the group larger than GROUP_SIZE.
5788 if (section_end_offset - group_begin_offset >= group_size)
5789 {
5790 if (stubs_always_after_branch)
5791 {
5792 gold_assert(group_end != this->input_sections().end());
5793 this->create_stub_group(group_begin, group_end, group_end,
5794 target, &new_relaxed_sections,
5795 task);
5796 state = NO_GROUP;
5797 }
5798 else
5799 {
5800 // But wait, there's more! Input sections up to
5801 // stub_group_size bytes after the stub table can be
5802 // handled by it too.
5803 state = HAS_STUB_SECTION;
5804 stub_table = group_end;
5805 stub_table_end_offset = group_end_offset;
5806 }
5807 }
5808 break;
5809
5810 case HAS_STUB_SECTION:
5811 // Adding this section makes the post stub-section group larger
5812 // than GROUP_SIZE.
5813 if (section_end_offset - stub_table_end_offset >= group_size)
5814 {
5815 gold_assert(group_end != this->input_sections().end());
5816 this->create_stub_group(group_begin, group_end, stub_table,
5817 target, &new_relaxed_sections, task);
5818 state = NO_GROUP;
5819 }
5820 break;
5821
5822 default:
5823 gold_unreachable();
5824 }
5825
5826 // If we see an input section and currently there is no group, start
5827 // a new one. Skip any empty sections. We look at the data size
5828 // instead of calling p->relobj()->section_size() to avoid locking.
5829 if ((p->is_input_section() || p->is_relaxed_input_section())
5830 && (p->data_size() != 0))
5831 {
5832 if (state == NO_GROUP)
5833 {
5834 state = FINDING_STUB_SECTION;
5835 group_begin = p;
5836 group_begin_offset = section_begin_offset;
5837 }
5838
5839 // Keep track of the last input section seen.
5840 group_end = p;
5841 group_end_offset = section_end_offset;
5842 }
5843
5844 off = section_end_offset;
5845 }
5846
5847 // Create a stub group for any ungrouped sections.
5848 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5849 {
5850 gold_assert(group_end != this->input_sections().end());
5851 this->create_stub_group(group_begin, group_end,
5852 (state == FINDING_STUB_SECTION
5853 ? group_end
5854 : stub_table),
5855 target, &new_relaxed_sections, task);
5856 }
5857
5858 // Convert input section into relaxed input section in a batch.
5859 if (!new_relaxed_sections.empty())
5860 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5861
5862 // Update the section offsets
5863 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5864 {
5865 Arm_relobj<big_endian>* arm_relobj =
5866 Arm_relobj<big_endian>::as_arm_relobj(
5867 new_relaxed_sections[i]->relobj());
5868 unsigned int shndx = new_relaxed_sections[i]->shndx();
5869 // Tell Arm_relobj that this input section is converted.
5870 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5871 }
5872 }
5873
5874 // Append non empty text sections in this to LIST in ascending
5875 // order of their position in this.
5876
5877 template<bool big_endian>
5878 void
5879 Arm_output_section<big_endian>::append_text_sections_to_list(
5880 Text_section_list* list)
5881 {
5882 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5883
5884 for (Input_section_list::const_iterator p = this->input_sections().begin();
5885 p != this->input_sections().end();
5886 ++p)
5887 {
5888 // We only care about plain or relaxed input sections. We also
5889 // ignore any merged sections.
5890 if (p->is_input_section() || p->is_relaxed_input_section())
5891 list->push_back(Text_section_list::value_type(p->relobj(),
5892 p->shndx()));
5893 }
5894 }
5895
5896 template<bool big_endian>
5897 void
5898 Arm_output_section<big_endian>::fix_exidx_coverage(
5899 Layout* layout,
5900 const Text_section_list& sorted_text_sections,
5901 Symbol_table* symtab,
5902 bool merge_exidx_entries,
5903 const Task* task)
5904 {
5905 // We should only do this for the EXIDX output section.
5906 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5907
5908 // We don't want the relaxation loop to undo these changes, so we discard
5909 // the current saved states and take another one after the fix-up.
5910 this->discard_states();
5911
5912 // Remove all input sections.
5913 uint64_t address = this->address();
5914 typedef std::list<Output_section::Input_section> Input_section_list;
5915 Input_section_list input_sections;
5916 this->reset_address_and_file_offset();
5917 this->get_input_sections(address, std::string(""), &input_sections);
5918
5919 if (!this->input_sections().empty())
5920 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5921
5922 // Go through all the known input sections and record them.
5923 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5924 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5925 Section_id_hash> Text_to_exidx_map;
5926 Text_to_exidx_map text_to_exidx_map;
5927 for (Input_section_list::const_iterator p = input_sections.begin();
5928 p != input_sections.end();
5929 ++p)
5930 {
5931 // This should never happen. At this point, we should only see
5932 // plain EXIDX input sections.
5933 gold_assert(!p->is_relaxed_input_section());
5934 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5935 }
5936
5937 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5938
5939 // Go over the sorted text sections.
5940 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5941 Section_id_set processed_input_sections;
5942 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5943 p != sorted_text_sections.end();
5944 ++p)
5945 {
5946 Relobj* relobj = p->first;
5947 unsigned int shndx = p->second;
5948
5949 Arm_relobj<big_endian>* arm_relobj =
5950 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5951 const Arm_exidx_input_section* exidx_input_section =
5952 arm_relobj->exidx_input_section_by_link(shndx);
5953
5954 // If this text section has no EXIDX section or if the EXIDX section
5955 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5956 // of the last seen EXIDX section.
5957 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5958 {
5959 exidx_fixup.add_exidx_cantunwind_as_needed();
5960 continue;
5961 }
5962
5963 Relobj* exidx_relobj = exidx_input_section->relobj();
5964 unsigned int exidx_shndx = exidx_input_section->shndx();
5965 Section_id sid(exidx_relobj, exidx_shndx);
5966 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5967 if (iter == text_to_exidx_map.end())
5968 {
5969 // This is odd. We have not seen this EXIDX input section before.
5970 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5971 // issue a warning instead. We assume the user knows what he
5972 // or she is doing. Otherwise, this is an error.
5973 if (layout->script_options()->saw_sections_clause())
5974 gold_warning(_("unwinding may not work because EXIDX input section"
5975 " %u of %s is not in EXIDX output section"),
5976 exidx_shndx, exidx_relobj->name().c_str());
5977 else
5978 gold_error(_("unwinding may not work because EXIDX input section"
5979 " %u of %s is not in EXIDX output section"),
5980 exidx_shndx, exidx_relobj->name().c_str());
5981
5982 exidx_fixup.add_exidx_cantunwind_as_needed();
5983 continue;
5984 }
5985
5986 // We need to access the contents of the EXIDX section, lock the
5987 // object here.
5988 Task_lock_obj<Object> tl(task, exidx_relobj);
5989 section_size_type exidx_size;
5990 const unsigned char* exidx_contents =
5991 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5992
5993 // Fix up coverage and append input section to output data list.
5994 Arm_exidx_section_offset_map* section_offset_map = NULL;
5995 uint32_t deleted_bytes =
5996 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5997 exidx_contents,
5998 exidx_size,
5999 &section_offset_map);
6000
6001 if (deleted_bytes == exidx_input_section->size())
6002 {
6003 // The whole EXIDX section got merged. Remove it from output.
6004 gold_assert(section_offset_map == NULL);
6005 exidx_relobj->set_output_section(exidx_shndx, NULL);
6006
6007 // All local symbols defined in this input section will be dropped.
6008 // We need to adjust output local symbol count.
6009 arm_relobj->set_output_local_symbol_count_needs_update();
6010 }
6011 else if (deleted_bytes > 0)
6012 {
6013 // Some entries are merged. We need to convert this EXIDX input
6014 // section into a relaxed section.
6015 gold_assert(section_offset_map != NULL);
6016
6017 Arm_exidx_merged_section* merged_section =
6018 new Arm_exidx_merged_section(*exidx_input_section,
6019 *section_offset_map, deleted_bytes);
6020 merged_section->build_contents(exidx_contents, exidx_size);
6021
6022 const std::string secname = exidx_relobj->section_name(exidx_shndx);
6023 this->add_relaxed_input_section(layout, merged_section, secname);
6024 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
6025
6026 // All local symbols defined in discarded portions of this input
6027 // section will be dropped. We need to adjust output local symbol
6028 // count.
6029 arm_relobj->set_output_local_symbol_count_needs_update();
6030 }
6031 else
6032 {
6033 // Just add back the EXIDX input section.
6034 gold_assert(section_offset_map == NULL);
6035 const Output_section::Input_section* pis = iter->second;
6036 gold_assert(pis->is_input_section());
6037 this->add_script_input_section(*pis);
6038 }
6039
6040 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
6041 }
6042
6043 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
6044 exidx_fixup.add_exidx_cantunwind_as_needed();
6045
6046 // Remove any known EXIDX input sections that are not processed.
6047 for (Input_section_list::const_iterator p = input_sections.begin();
6048 p != input_sections.end();
6049 ++p)
6050 {
6051 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
6052 == processed_input_sections.end())
6053 {
6054 // We discard a known EXIDX section because its linked
6055 // text section has been folded by ICF. We also discard an
6056 // EXIDX section with error, the output does not matter in this
6057 // case. We do this to avoid triggering asserts.
6058 Arm_relobj<big_endian>* arm_relobj =
6059 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6060 const Arm_exidx_input_section* exidx_input_section =
6061 arm_relobj->exidx_input_section_by_shndx(p->shndx());
6062 gold_assert(exidx_input_section != NULL);
6063 if (!exidx_input_section->has_errors())
6064 {
6065 unsigned int text_shndx = exidx_input_section->link();
6066 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
6067 }
6068
6069 // Remove this from link. We also need to recount the
6070 // local symbols.
6071 p->relobj()->set_output_section(p->shndx(), NULL);
6072 arm_relobj->set_output_local_symbol_count_needs_update();
6073 }
6074 }
6075
6076 // Link exidx output section to the first seen output section and
6077 // set correct entry size.
6078 this->set_link_section(exidx_fixup.first_output_text_section());
6079 this->set_entsize(8);
6080
6081 // Make changes permanent.
6082 this->save_states();
6083 this->set_section_offsets_need_adjustment();
6084 }
6085
6086 // Link EXIDX output sections to text output sections.
6087
6088 template<bool big_endian>
6089 void
6090 Arm_output_section<big_endian>::set_exidx_section_link()
6091 {
6092 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6093 if (!this->input_sections().empty())
6094 {
6095 Input_section_list::const_iterator p = this->input_sections().begin();
6096 Arm_relobj<big_endian>* arm_relobj =
6097 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6098 unsigned exidx_shndx = p->shndx();
6099 const Arm_exidx_input_section* exidx_input_section =
6100 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6101 gold_assert(exidx_input_section != NULL);
6102 unsigned int text_shndx = exidx_input_section->link();
6103 Output_section* os = arm_relobj->output_section(text_shndx);
6104 this->set_link_section(os);
6105 }
6106 }
6107
6108 // Arm_relobj methods.
6109
6110 // Determine if an input section is scannable for stub processing. SHDR is
6111 // the header of the section and SHNDX is the section index. OS is the output
6112 // section for the input section and SYMTAB is the global symbol table used to
6113 // look up ICF information.
6114
6115 template<bool big_endian>
6116 bool
6117 Arm_relobj<big_endian>::section_is_scannable(
6118 const elfcpp::Shdr<32, big_endian>& shdr,
6119 unsigned int shndx,
6120 const Output_section* os,
6121 const Symbol_table* symtab)
6122 {
6123 // Skip any empty sections, unallocated sections or sections whose
6124 // type are not SHT_PROGBITS.
6125 if (shdr.get_sh_size() == 0
6126 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6127 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6128 return false;
6129
6130 // Skip any discarded or ICF'ed sections.
6131 if (os == NULL || symtab->is_section_folded(this, shndx))
6132 return false;
6133
6134 // If this requires special offset handling, check to see if it is
6135 // a relaxed section. If this is not, then it is a merged section that
6136 // we cannot handle.
6137 if (this->is_output_section_offset_invalid(shndx))
6138 {
6139 const Output_relaxed_input_section* poris =
6140 os->find_relaxed_input_section(this, shndx);
6141 if (poris == NULL)
6142 return false;
6143 }
6144
6145 return true;
6146 }
6147
6148 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6149 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6150
6151 template<bool big_endian>
6152 bool
6153 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6154 const elfcpp::Shdr<32, big_endian>& shdr,
6155 const Relobj::Output_sections& out_sections,
6156 const Symbol_table* symtab,
6157 const unsigned char* pshdrs)
6158 {
6159 unsigned int sh_type = shdr.get_sh_type();
6160 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6161 return false;
6162
6163 // Ignore empty section.
6164 off_t sh_size = shdr.get_sh_size();
6165 if (sh_size == 0)
6166 return false;
6167
6168 // Ignore reloc section with unexpected symbol table. The
6169 // error will be reported in the final link.
6170 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6171 return false;
6172
6173 unsigned int reloc_size;
6174 if (sh_type == elfcpp::SHT_REL)
6175 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6176 else
6177 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6178
6179 // Ignore reloc section with unexpected entsize or uneven size.
6180 // The error will be reported in the final link.
6181 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6182 return false;
6183
6184 // Ignore reloc section with bad info. This error will be
6185 // reported in the final link.
6186 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6187 if (index >= this->shnum())
6188 return false;
6189
6190 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6191 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6192 return this->section_is_scannable(text_shdr, index,
6193 out_sections[index], symtab);
6194 }
6195
6196 // Return the output address of either a plain input section or a relaxed
6197 // input section. SHNDX is the section index. We define and use this
6198 // instead of calling Output_section::output_address because that is slow
6199 // for large output.
6200
6201 template<bool big_endian>
6202 Arm_address
6203 Arm_relobj<big_endian>::simple_input_section_output_address(
6204 unsigned int shndx,
6205 Output_section* os)
6206 {
6207 if (this->is_output_section_offset_invalid(shndx))
6208 {
6209 const Output_relaxed_input_section* poris =
6210 os->find_relaxed_input_section(this, shndx);
6211 // We do not handle merged sections here.
6212 gold_assert(poris != NULL);
6213 return poris->address();
6214 }
6215 else
6216 return os->address() + this->get_output_section_offset(shndx);
6217 }
6218
6219 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6220 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6221
6222 template<bool big_endian>
6223 bool
6224 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6225 const elfcpp::Shdr<32, big_endian>& shdr,
6226 unsigned int shndx,
6227 Output_section* os,
6228 const Symbol_table* symtab)
6229 {
6230 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6231 return false;
6232
6233 // If the section does not cross any 4K-boundaries, it does not need to
6234 // be scanned.
6235 Arm_address address = this->simple_input_section_output_address(shndx, os);
6236 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6237 return false;
6238
6239 return true;
6240 }
6241
6242 // Scan a section for Cortex-A8 workaround.
6243
6244 template<bool big_endian>
6245 void
6246 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6247 const elfcpp::Shdr<32, big_endian>& shdr,
6248 unsigned int shndx,
6249 Output_section* os,
6250 Target_arm<big_endian>* arm_target)
6251 {
6252 // Look for the first mapping symbol in this section. It should be
6253 // at (shndx, 0).
6254 Mapping_symbol_position section_start(shndx, 0);
6255 typename Mapping_symbols_info::const_iterator p =
6256 this->mapping_symbols_info_.lower_bound(section_start);
6257
6258 // There are no mapping symbols for this section. Treat it as a data-only
6259 // section.
6260 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6261 return;
6262
6263 Arm_address output_address =
6264 this->simple_input_section_output_address(shndx, os);
6265
6266 // Get the section contents.
6267 section_size_type input_view_size = 0;
6268 const unsigned char* input_view =
6269 this->section_contents(shndx, &input_view_size, false);
6270
6271 // We need to go through the mapping symbols to determine what to
6272 // scan. There are two reasons. First, we should look at THUMB code and
6273 // THUMB code only. Second, we only want to look at the 4K-page boundary
6274 // to speed up the scanning.
6275
6276 while (p != this->mapping_symbols_info_.end()
6277 && p->first.first == shndx)
6278 {
6279 typename Mapping_symbols_info::const_iterator next =
6280 this->mapping_symbols_info_.upper_bound(p->first);
6281
6282 // Only scan part of a section with THUMB code.
6283 if (p->second == 't')
6284 {
6285 // Determine the end of this range.
6286 section_size_type span_start =
6287 convert_to_section_size_type(p->first.second);
6288 section_size_type span_end;
6289 if (next != this->mapping_symbols_info_.end()
6290 && next->first.first == shndx)
6291 span_end = convert_to_section_size_type(next->first.second);
6292 else
6293 span_end = convert_to_section_size_type(shdr.get_sh_size());
6294
6295 if (((span_start + output_address) & ~0xfffUL)
6296 != ((span_end + output_address - 1) & ~0xfffUL))
6297 {
6298 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6299 span_start, span_end,
6300 input_view,
6301 output_address);
6302 }
6303 }
6304
6305 p = next;
6306 }
6307 }
6308
6309 // Scan relocations for stub generation.
6310
6311 template<bool big_endian>
6312 void
6313 Arm_relobj<big_endian>::scan_sections_for_stubs(
6314 Target_arm<big_endian>* arm_target,
6315 const Symbol_table* symtab,
6316 const Layout* layout)
6317 {
6318 unsigned int shnum = this->shnum();
6319 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6320
6321 // Read the section headers.
6322 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6323 shnum * shdr_size,
6324 true, true);
6325
6326 // To speed up processing, we set up hash tables for fast lookup of
6327 // input offsets to output addresses.
6328 this->initialize_input_to_output_maps();
6329
6330 const Relobj::Output_sections& out_sections(this->output_sections());
6331
6332 Relocate_info<32, big_endian> relinfo;
6333 relinfo.symtab = symtab;
6334 relinfo.layout = layout;
6335 relinfo.object = this;
6336
6337 // Do relocation stubs scanning.
6338 const unsigned char* p = pshdrs + shdr_size;
6339 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6340 {
6341 const elfcpp::Shdr<32, big_endian> shdr(p);
6342 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6343 pshdrs))
6344 {
6345 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6346 Arm_address output_offset = this->get_output_section_offset(index);
6347 Arm_address output_address;
6348 if (output_offset != invalid_address)
6349 output_address = out_sections[index]->address() + output_offset;
6350 else
6351 {
6352 // Currently this only happens for a relaxed section.
6353 const Output_relaxed_input_section* poris =
6354 out_sections[index]->find_relaxed_input_section(this, index);
6355 gold_assert(poris != NULL);
6356 output_address = poris->address();
6357 }
6358
6359 // Get the relocations.
6360 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6361 shdr.get_sh_size(),
6362 true, false);
6363
6364 // Get the section contents. This does work for the case in which
6365 // we modify the contents of an input section. We need to pass the
6366 // output view under such circumstances.
6367 section_size_type input_view_size = 0;
6368 const unsigned char* input_view =
6369 this->section_contents(index, &input_view_size, false);
6370
6371 relinfo.reloc_shndx = i;
6372 relinfo.data_shndx = index;
6373 unsigned int sh_type = shdr.get_sh_type();
6374 unsigned int reloc_size;
6375 if (sh_type == elfcpp::SHT_REL)
6376 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6377 else
6378 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6379
6380 Output_section* os = out_sections[index];
6381 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6382 shdr.get_sh_size() / reloc_size,
6383 os,
6384 output_offset == invalid_address,
6385 input_view, output_address,
6386 input_view_size);
6387 }
6388 }
6389
6390 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6391 // after its relocation section, if there is one, is processed for
6392 // relocation stubs. Merging this loop with the one above would have been
6393 // complicated since we would have had to make sure that relocation stub
6394 // scanning is done first.
6395 if (arm_target->fix_cortex_a8())
6396 {
6397 const unsigned char* p = pshdrs + shdr_size;
6398 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6399 {
6400 const elfcpp::Shdr<32, big_endian> shdr(p);
6401 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6402 out_sections[i],
6403 symtab))
6404 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6405 arm_target);
6406 }
6407 }
6408
6409 // After we've done the relocations, we release the hash tables,
6410 // since we no longer need them.
6411 this->free_input_to_output_maps();
6412 }
6413
6414 // Count the local symbols. The ARM backend needs to know if a symbol
6415 // is a THUMB function or not. For global symbols, it is easy because
6416 // the Symbol object keeps the ELF symbol type. For local symbol it is
6417 // harder because we cannot access this information. So we override the
6418 // do_count_local_symbol in parent and scan local symbols to mark
6419 // THUMB functions. This is not the most efficient way but I do not want to
6420 // slow down other ports by calling a per symbol target hook inside
6421 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6422
6423 template<bool big_endian>
6424 void
6425 Arm_relobj<big_endian>::do_count_local_symbols(
6426 Stringpool_template<char>* pool,
6427 Stringpool_template<char>* dynpool)
6428 {
6429 // We need to fix-up the values of any local symbols whose type are
6430 // STT_ARM_TFUNC.
6431
6432 // Ask parent to count the local symbols.
6433 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6434 const unsigned int loccount = this->local_symbol_count();
6435 if (loccount == 0)
6436 return;
6437
6438 // Initialize the thumb function bit-vector.
6439 std::vector<bool> empty_vector(loccount, false);
6440 this->local_symbol_is_thumb_function_.swap(empty_vector);
6441
6442 // Read the symbol table section header.
6443 const unsigned int symtab_shndx = this->symtab_shndx();
6444 elfcpp::Shdr<32, big_endian>
6445 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6446 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6447
6448 // Read the local symbols.
6449 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6450 gold_assert(loccount == symtabshdr.get_sh_info());
6451 off_t locsize = loccount * sym_size;
6452 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6453 locsize, true, true);
6454
6455 // For mapping symbol processing, we need to read the symbol names.
6456 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6457 if (strtab_shndx >= this->shnum())
6458 {
6459 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6460 return;
6461 }
6462
6463 elfcpp::Shdr<32, big_endian>
6464 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6465 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6466 {
6467 this->error(_("symbol table name section has wrong type: %u"),
6468 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6469 return;
6470 }
6471 const char* pnames =
6472 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6473 strtabshdr.get_sh_size(),
6474 false, false));
6475
6476 // Loop over the local symbols and mark any local symbols pointing
6477 // to THUMB functions.
6478
6479 // Skip the first dummy symbol.
6480 psyms += sym_size;
6481 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6482 this->local_values();
6483 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6484 {
6485 elfcpp::Sym<32, big_endian> sym(psyms);
6486 elfcpp::STT st_type = sym.get_st_type();
6487 Symbol_value<32>& lv((*plocal_values)[i]);
6488 Arm_address input_value = lv.input_value();
6489
6490 // Check to see if this is a mapping symbol.
6491 const char* sym_name = pnames + sym.get_st_name();
6492 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6493 {
6494 bool is_ordinary;
6495 unsigned int input_shndx =
6496 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6497 gold_assert(is_ordinary);
6498
6499 // Strip of LSB in case this is a THUMB symbol.
6500 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6501 this->mapping_symbols_info_[msp] = sym_name[1];
6502 }
6503
6504 if (st_type == elfcpp::STT_ARM_TFUNC
6505 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6506 {
6507 // This is a THUMB function. Mark this and canonicalize the
6508 // symbol value by setting LSB.
6509 this->local_symbol_is_thumb_function_[i] = true;
6510 if ((input_value & 1) == 0)
6511 lv.set_input_value(input_value | 1);
6512 }
6513 }
6514 }
6515
6516 // Relocate sections.
6517 template<bool big_endian>
6518 void
6519 Arm_relobj<big_endian>::do_relocate_sections(
6520 const Symbol_table* symtab,
6521 const Layout* layout,
6522 const unsigned char* pshdrs,
6523 Output_file* of,
6524 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6525 {
6526 // Call parent to relocate sections.
6527 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6528 pshdrs, of, pviews);
6529
6530 // We do not generate stubs if doing a relocatable link.
6531 if (parameters->options().relocatable())
6532 return;
6533
6534 // Relocate stub tables.
6535 unsigned int shnum = this->shnum();
6536
6537 Target_arm<big_endian>* arm_target =
6538 Target_arm<big_endian>::default_target();
6539
6540 Relocate_info<32, big_endian> relinfo;
6541 relinfo.symtab = symtab;
6542 relinfo.layout = layout;
6543 relinfo.object = this;
6544
6545 for (unsigned int i = 1; i < shnum; ++i)
6546 {
6547 Arm_input_section<big_endian>* arm_input_section =
6548 arm_target->find_arm_input_section(this, i);
6549
6550 if (arm_input_section != NULL
6551 && arm_input_section->is_stub_table_owner()
6552 && !arm_input_section->stub_table()->empty())
6553 {
6554 // We cannot discard a section if it owns a stub table.
6555 Output_section* os = this->output_section(i);
6556 gold_assert(os != NULL);
6557
6558 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6559 relinfo.reloc_shdr = NULL;
6560 relinfo.data_shndx = i;
6561 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6562
6563 gold_assert((*pviews)[i].view != NULL);
6564
6565 // We are passed the output section view. Adjust it to cover the
6566 // stub table only.
6567 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6568 gold_assert((stub_table->address() >= (*pviews)[i].address)
6569 && ((stub_table->address() + stub_table->data_size())
6570 <= (*pviews)[i].address + (*pviews)[i].view_size));
6571
6572 off_t offset = stub_table->address() - (*pviews)[i].address;
6573 unsigned char* view = (*pviews)[i].view + offset;
6574 Arm_address address = stub_table->address();
6575 section_size_type view_size = stub_table->data_size();
6576
6577 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6578 view_size);
6579 }
6580
6581 // Apply Cortex A8 workaround if applicable.
6582 if (this->section_has_cortex_a8_workaround(i))
6583 {
6584 unsigned char* view = (*pviews)[i].view;
6585 Arm_address view_address = (*pviews)[i].address;
6586 section_size_type view_size = (*pviews)[i].view_size;
6587 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6588
6589 // Adjust view to cover section.
6590 Output_section* os = this->output_section(i);
6591 gold_assert(os != NULL);
6592 Arm_address section_address =
6593 this->simple_input_section_output_address(i, os);
6594 uint64_t section_size = this->section_size(i);
6595
6596 gold_assert(section_address >= view_address
6597 && ((section_address + section_size)
6598 <= (view_address + view_size)));
6599
6600 unsigned char* section_view = view + (section_address - view_address);
6601
6602 // Apply the Cortex-A8 workaround to the output address range
6603 // corresponding to this input section.
6604 stub_table->apply_cortex_a8_workaround_to_address_range(
6605 arm_target,
6606 section_view,
6607 section_address,
6608 section_size);
6609 }
6610 }
6611 }
6612
6613 // Find the linked text section of an EXIDX section by looking at the first
6614 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6615 // must be linked to its associated code section via the sh_link field of
6616 // its section header. However, some tools are broken and the link is not
6617 // always set. LD just drops such an EXIDX section silently, causing the
6618 // associated code not unwindabled. Here we try a little bit harder to
6619 // discover the linked code section.
6620 //
6621 // PSHDR points to the section header of a relocation section of an EXIDX
6622 // section. If we can find a linked text section, return true and
6623 // store the text section index in the location PSHNDX. Otherwise
6624 // return false.
6625
6626 template<bool big_endian>
6627 bool
6628 Arm_relobj<big_endian>::find_linked_text_section(
6629 const unsigned char* pshdr,
6630 const unsigned char* psyms,
6631 unsigned int* pshndx)
6632 {
6633 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6634
6635 // If there is no relocation, we cannot find the linked text section.
6636 size_t reloc_size;
6637 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6638 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6639 else
6640 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6641 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6642
6643 // Get the relocations.
6644 const unsigned char* prelocs =
6645 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6646
6647 // Find the REL31 relocation for the first word of the first EXIDX entry.
6648 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6649 {
6650 Arm_address r_offset;
6651 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6652 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6653 {
6654 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6655 r_info = reloc.get_r_info();
6656 r_offset = reloc.get_r_offset();
6657 }
6658 else
6659 {
6660 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6661 r_info = reloc.get_r_info();
6662 r_offset = reloc.get_r_offset();
6663 }
6664
6665 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6666 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6667 continue;
6668
6669 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6670 if (r_sym == 0
6671 || r_sym >= this->local_symbol_count()
6672 || r_offset != 0)
6673 continue;
6674
6675 // This is the relocation for the first word of the first EXIDX entry.
6676 // We expect to see a local section symbol.
6677 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6678 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6679 if (sym.get_st_type() == elfcpp::STT_SECTION)
6680 {
6681 bool is_ordinary;
6682 *pshndx =
6683 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6684 gold_assert(is_ordinary);
6685 return true;
6686 }
6687 else
6688 return false;
6689 }
6690
6691 return false;
6692 }
6693
6694 // Make an EXIDX input section object for an EXIDX section whose index is
6695 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6696 // is the section index of the linked text section.
6697
6698 template<bool big_endian>
6699 void
6700 Arm_relobj<big_endian>::make_exidx_input_section(
6701 unsigned int shndx,
6702 const elfcpp::Shdr<32, big_endian>& shdr,
6703 unsigned int text_shndx,
6704 const elfcpp::Shdr<32, big_endian>& text_shdr)
6705 {
6706 // Create an Arm_exidx_input_section object for this EXIDX section.
6707 Arm_exidx_input_section* exidx_input_section =
6708 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6709 shdr.get_sh_addralign(),
6710 text_shdr.get_sh_size());
6711
6712 gold_assert(this->exidx_section_map_[shndx] == NULL);
6713 this->exidx_section_map_[shndx] = exidx_input_section;
6714
6715 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6716 {
6717 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6718 this->section_name(shndx).c_str(), shndx, text_shndx,
6719 this->name().c_str());
6720 exidx_input_section->set_has_errors();
6721 }
6722 else if (this->exidx_section_map_[text_shndx] != NULL)
6723 {
6724 unsigned other_exidx_shndx =
6725 this->exidx_section_map_[text_shndx]->shndx();
6726 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6727 "%s(%u) in %s"),
6728 this->section_name(shndx).c_str(), shndx,
6729 this->section_name(other_exidx_shndx).c_str(),
6730 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6731 text_shndx, this->name().c_str());
6732 exidx_input_section->set_has_errors();
6733 }
6734 else
6735 this->exidx_section_map_[text_shndx] = exidx_input_section;
6736
6737 // Check section flags of text section.
6738 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6739 {
6740 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6741 " in %s"),
6742 this->section_name(shndx).c_str(), shndx,
6743 this->section_name(text_shndx).c_str(), text_shndx,
6744 this->name().c_str());
6745 exidx_input_section->set_has_errors();
6746 }
6747 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6748 // I would like to make this an error but currently ld just ignores
6749 // this.
6750 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6751 "%s(%u) in %s"),
6752 this->section_name(shndx).c_str(), shndx,
6753 this->section_name(text_shndx).c_str(), text_shndx,
6754 this->name().c_str());
6755 }
6756
6757 // Read the symbol information.
6758
6759 template<bool big_endian>
6760 void
6761 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6762 {
6763 // Call parent class to read symbol information.
6764 this->base_read_symbols(sd);
6765
6766 // If this input file is a binary file, it has no processor
6767 // specific flags and attributes section.
6768 Input_file::Format format = this->input_file()->format();
6769 if (format != Input_file::FORMAT_ELF)
6770 {
6771 gold_assert(format == Input_file::FORMAT_BINARY);
6772 this->merge_flags_and_attributes_ = false;
6773 return;
6774 }
6775
6776 // Read processor-specific flags in ELF file header.
6777 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6778 elfcpp::Elf_sizes<32>::ehdr_size,
6779 true, false);
6780 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6781 this->processor_specific_flags_ = ehdr.get_e_flags();
6782
6783 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6784 // sections.
6785 std::vector<unsigned int> deferred_exidx_sections;
6786 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6787 const unsigned char* pshdrs = sd->section_headers->data();
6788 const unsigned char* ps = pshdrs + shdr_size;
6789 bool must_merge_flags_and_attributes = false;
6790 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6791 {
6792 elfcpp::Shdr<32, big_endian> shdr(ps);
6793
6794 // Sometimes an object has no contents except the section name string
6795 // table and an empty symbol table with the undefined symbol. We
6796 // don't want to merge processor-specific flags from such an object.
6797 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6798 {
6799 // Symbol table is not empty.
6800 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6801 elfcpp::Elf_sizes<32>::sym_size;
6802 if (shdr.get_sh_size() > sym_size)
6803 must_merge_flags_and_attributes = true;
6804 }
6805 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6806 // If this is neither an empty symbol table nor a string table,
6807 // be conservative.
6808 must_merge_flags_and_attributes = true;
6809
6810 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6811 {
6812 gold_assert(this->attributes_section_data_ == NULL);
6813 section_offset_type section_offset = shdr.get_sh_offset();
6814 section_size_type section_size =
6815 convert_to_section_size_type(shdr.get_sh_size());
6816 const unsigned char* view =
6817 this->get_view(section_offset, section_size, true, false);
6818 this->attributes_section_data_ =
6819 new Attributes_section_data(view, section_size);
6820 }
6821 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6822 {
6823 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6824 if (text_shndx == elfcpp::SHN_UNDEF)
6825 deferred_exidx_sections.push_back(i);
6826 else
6827 {
6828 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6829 + text_shndx * shdr_size);
6830 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6831 }
6832 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6833 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6834 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6835 this->section_name(i).c_str(), this->name().c_str());
6836 }
6837 }
6838
6839 // This is rare.
6840 if (!must_merge_flags_and_attributes)
6841 {
6842 gold_assert(deferred_exidx_sections.empty());
6843 this->merge_flags_and_attributes_ = false;
6844 return;
6845 }
6846
6847 // Some tools are broken and they do not set the link of EXIDX sections.
6848 // We look at the first relocation to figure out the linked sections.
6849 if (!deferred_exidx_sections.empty())
6850 {
6851 // We need to go over the section headers again to find the mapping
6852 // from sections being relocated to their relocation sections. This is
6853 // a bit inefficient as we could do that in the loop above. However,
6854 // we do not expect any deferred EXIDX sections normally. So we do not
6855 // want to slow down the most common path.
6856 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6857 Reloc_map reloc_map;
6858 ps = pshdrs + shdr_size;
6859 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6860 {
6861 elfcpp::Shdr<32, big_endian> shdr(ps);
6862 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6863 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6864 {
6865 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6866 if (info_shndx >= this->shnum())
6867 gold_error(_("relocation section %u has invalid info %u"),
6868 i, info_shndx);
6869 Reloc_map::value_type value(info_shndx, i);
6870 std::pair<Reloc_map::iterator, bool> result =
6871 reloc_map.insert(value);
6872 if (!result.second)
6873 gold_error(_("section %u has multiple relocation sections "
6874 "%u and %u"),
6875 info_shndx, i, reloc_map[info_shndx]);
6876 }
6877 }
6878
6879 // Read the symbol table section header.
6880 const unsigned int symtab_shndx = this->symtab_shndx();
6881 elfcpp::Shdr<32, big_endian>
6882 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6883 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6884
6885 // Read the local symbols.
6886 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6887 const unsigned int loccount = this->local_symbol_count();
6888 gold_assert(loccount == symtabshdr.get_sh_info());
6889 off_t locsize = loccount * sym_size;
6890 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6891 locsize, true, true);
6892
6893 // Process the deferred EXIDX sections.
6894 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6895 {
6896 unsigned int shndx = deferred_exidx_sections[i];
6897 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6898 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6899 Reloc_map::const_iterator it = reloc_map.find(shndx);
6900 if (it != reloc_map.end())
6901 find_linked_text_section(pshdrs + it->second * shdr_size,
6902 psyms, &text_shndx);
6903 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6904 + text_shndx * shdr_size);
6905 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6906 }
6907 }
6908 }
6909
6910 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6911 // sections for unwinding. These sections are referenced implicitly by
6912 // text sections linked in the section headers. If we ignore these implicit
6913 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6914 // will be garbage-collected incorrectly. Hence we override the same function
6915 // in the base class to handle these implicit references.
6916
6917 template<bool big_endian>
6918 void
6919 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6920 Layout* layout,
6921 Read_relocs_data* rd)
6922 {
6923 // First, call base class method to process relocations in this object.
6924 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6925
6926 // If --gc-sections is not specified, there is nothing more to do.
6927 // This happens when --icf is used but --gc-sections is not.
6928 if (!parameters->options().gc_sections())
6929 return;
6930
6931 unsigned int shnum = this->shnum();
6932 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6933 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6934 shnum * shdr_size,
6935 true, true);
6936
6937 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6938 // to these from the linked text sections.
6939 const unsigned char* ps = pshdrs + shdr_size;
6940 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6941 {
6942 elfcpp::Shdr<32, big_endian> shdr(ps);
6943 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6944 {
6945 // Found an .ARM.exidx section, add it to the set of reachable
6946 // sections from its linked text section.
6947 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6948 symtab->gc()->add_reference(this, text_shndx, this, i);
6949 }
6950 }
6951 }
6952
6953 // Update output local symbol count. Owing to EXIDX entry merging, some local
6954 // symbols will be removed in output. Adjust output local symbol count
6955 // accordingly. We can only changed the static output local symbol count. It
6956 // is too late to change the dynamic symbols.
6957
6958 template<bool big_endian>
6959 void
6960 Arm_relobj<big_endian>::update_output_local_symbol_count()
6961 {
6962 // Caller should check that this needs updating. We want caller checking
6963 // because output_local_symbol_count_needs_update() is most likely inlined.
6964 gold_assert(this->output_local_symbol_count_needs_update_);
6965
6966 gold_assert(this->symtab_shndx() != -1U);
6967 if (this->symtab_shndx() == 0)
6968 {
6969 // This object has no symbols. Weird but legal.
6970 return;
6971 }
6972
6973 // Read the symbol table section header.
6974 const unsigned int symtab_shndx = this->symtab_shndx();
6975 elfcpp::Shdr<32, big_endian>
6976 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6977 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6978
6979 // Read the local symbols.
6980 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6981 const unsigned int loccount = this->local_symbol_count();
6982 gold_assert(loccount == symtabshdr.get_sh_info());
6983 off_t locsize = loccount * sym_size;
6984 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6985 locsize, true, true);
6986
6987 // Loop over the local symbols.
6988
6989 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6990 Output_sections;
6991 const Output_sections& out_sections(this->output_sections());
6992 unsigned int shnum = this->shnum();
6993 unsigned int count = 0;
6994 // Skip the first, dummy, symbol.
6995 psyms += sym_size;
6996 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6997 {
6998 elfcpp::Sym<32, big_endian> sym(psyms);
6999
7000 Symbol_value<32>& lv((*this->local_values())[i]);
7001
7002 // This local symbol was already discarded by do_count_local_symbols.
7003 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
7004 continue;
7005
7006 bool is_ordinary;
7007 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
7008 &is_ordinary);
7009
7010 if (shndx < shnum)
7011 {
7012 Output_section* os = out_sections[shndx];
7013
7014 // This local symbol no longer has an output section. Discard it.
7015 if (os == NULL)
7016 {
7017 lv.set_no_output_symtab_entry();
7018 continue;
7019 }
7020
7021 // Currently we only discard parts of EXIDX input sections.
7022 // We explicitly check for a merged EXIDX input section to avoid
7023 // calling Output_section_data::output_offset unless necessary.
7024 if ((this->get_output_section_offset(shndx) == invalid_address)
7025 && (this->exidx_input_section_by_shndx(shndx) != NULL))
7026 {
7027 section_offset_type output_offset =
7028 os->output_offset(this, shndx, lv.input_value());
7029 if (output_offset == -1)
7030 {
7031 // This symbol is defined in a part of an EXIDX input section
7032 // that is discarded due to entry merging.
7033 lv.set_no_output_symtab_entry();
7034 continue;
7035 }
7036 }
7037 }
7038
7039 ++count;
7040 }
7041
7042 this->set_output_local_symbol_count(count);
7043 this->output_local_symbol_count_needs_update_ = false;
7044 }
7045
7046 // Arm_dynobj methods.
7047
7048 // Read the symbol information.
7049
7050 template<bool big_endian>
7051 void
7052 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
7053 {
7054 // Call parent class to read symbol information.
7055 this->base_read_symbols(sd);
7056
7057 // Read processor-specific flags in ELF file header.
7058 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
7059 elfcpp::Elf_sizes<32>::ehdr_size,
7060 true, false);
7061 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
7062 this->processor_specific_flags_ = ehdr.get_e_flags();
7063
7064 // Read the attributes section if there is one.
7065 // We read from the end because gas seems to put it near the end of
7066 // the section headers.
7067 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
7068 const unsigned char* ps =
7069 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
7070 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
7071 {
7072 elfcpp::Shdr<32, big_endian> shdr(ps);
7073 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
7074 {
7075 section_offset_type section_offset = shdr.get_sh_offset();
7076 section_size_type section_size =
7077 convert_to_section_size_type(shdr.get_sh_size());
7078 const unsigned char* view =
7079 this->get_view(section_offset, section_size, true, false);
7080 this->attributes_section_data_ =
7081 new Attributes_section_data(view, section_size);
7082 break;
7083 }
7084 }
7085 }
7086
7087 // Stub_addend_reader methods.
7088
7089 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7090
7091 template<bool big_endian>
7092 elfcpp::Elf_types<32>::Elf_Swxword
7093 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7094 unsigned int r_type,
7095 const unsigned char* view,
7096 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7097 {
7098 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7099
7100 switch (r_type)
7101 {
7102 case elfcpp::R_ARM_CALL:
7103 case elfcpp::R_ARM_JUMP24:
7104 case elfcpp::R_ARM_PLT32:
7105 {
7106 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7107 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7108 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7109 return Bits<26>::sign_extend32(val << 2);
7110 }
7111
7112 case elfcpp::R_ARM_THM_CALL:
7113 case elfcpp::R_ARM_THM_JUMP24:
7114 case elfcpp::R_ARM_THM_XPC22:
7115 {
7116 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7117 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7118 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7119 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7120 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7121 }
7122
7123 case elfcpp::R_ARM_THM_JUMP19:
7124 {
7125 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7126 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7127 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7128 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7129 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7130 }
7131
7132 default:
7133 gold_unreachable();
7134 }
7135 }
7136
7137 // Arm_output_data_got methods.
7138
7139 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7140 // The first one is initialized to be 1, which is the module index for
7141 // the main executable and the second one 0. A reloc of the type
7142 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7143 // be applied by gold. GSYM is a global symbol.
7144 //
7145 template<bool big_endian>
7146 void
7147 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7148 unsigned int got_type,
7149 Symbol* gsym)
7150 {
7151 if (gsym->has_got_offset(got_type))
7152 return;
7153
7154 // We are doing a static link. Just mark it as belong to module 1,
7155 // the executable.
7156 unsigned int got_offset = this->add_constant(1);
7157 gsym->set_got_offset(got_type, got_offset);
7158 got_offset = this->add_constant(0);
7159 this->static_relocs_.push_back(Static_reloc(got_offset,
7160 elfcpp::R_ARM_TLS_DTPOFF32,
7161 gsym));
7162 }
7163
7164 // Same as the above but for a local symbol.
7165
7166 template<bool big_endian>
7167 void
7168 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7169 unsigned int got_type,
7170 Sized_relobj_file<32, big_endian>* object,
7171 unsigned int index)
7172 {
7173 if (object->local_has_got_offset(index, got_type))
7174 return;
7175
7176 // We are doing a static link. Just mark it as belong to module 1,
7177 // the executable.
7178 unsigned int got_offset = this->add_constant(1);
7179 object->set_local_got_offset(index, got_type, got_offset);
7180 got_offset = this->add_constant(0);
7181 this->static_relocs_.push_back(Static_reloc(got_offset,
7182 elfcpp::R_ARM_TLS_DTPOFF32,
7183 object, index));
7184 }
7185
7186 template<bool big_endian>
7187 void
7188 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7189 {
7190 // Call parent to write out GOT.
7191 Output_data_got<32, big_endian>::do_write(of);
7192
7193 // We are done if there is no fix up.
7194 if (this->static_relocs_.empty())
7195 return;
7196
7197 gold_assert(parameters->doing_static_link());
7198
7199 const off_t offset = this->offset();
7200 const section_size_type oview_size =
7201 convert_to_section_size_type(this->data_size());
7202 unsigned char* const oview = of->get_output_view(offset, oview_size);
7203
7204 Output_segment* tls_segment = this->layout_->tls_segment();
7205 gold_assert(tls_segment != NULL);
7206
7207 // The thread pointer $tp points to the TCB, which is followed by the
7208 // TLS. So we need to adjust $tp relative addressing by this amount.
7209 Arm_address aligned_tcb_size =
7210 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7211
7212 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7213 {
7214 Static_reloc& reloc(this->static_relocs_[i]);
7215
7216 Arm_address value;
7217 if (!reloc.symbol_is_global())
7218 {
7219 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7220 const Symbol_value<32>* psymval =
7221 reloc.relobj()->local_symbol(reloc.index());
7222
7223 // We are doing static linking. Issue an error and skip this
7224 // relocation if the symbol is undefined or in a discarded_section.
7225 bool is_ordinary;
7226 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7227 if ((shndx == elfcpp::SHN_UNDEF)
7228 || (is_ordinary
7229 && shndx != elfcpp::SHN_UNDEF
7230 && !object->is_section_included(shndx)
7231 && !this->symbol_table_->is_section_folded(object, shndx)))
7232 {
7233 gold_error(_("undefined or discarded local symbol %u from "
7234 " object %s in GOT"),
7235 reloc.index(), reloc.relobj()->name().c_str());
7236 continue;
7237 }
7238
7239 value = psymval->value(object, 0);
7240 }
7241 else
7242 {
7243 const Symbol* gsym = reloc.symbol();
7244 gold_assert(gsym != NULL);
7245 if (gsym->is_forwarder())
7246 gsym = this->symbol_table_->resolve_forwards(gsym);
7247
7248 // We are doing static linking. Issue an error and skip this
7249 // relocation if the symbol is undefined or in a discarded_section
7250 // unless it is a weakly_undefined symbol.
7251 if ((gsym->is_defined_in_discarded_section()
7252 || gsym->is_undefined())
7253 && !gsym->is_weak_undefined())
7254 {
7255 gold_error(_("undefined or discarded symbol %s in GOT"),
7256 gsym->name());
7257 continue;
7258 }
7259
7260 if (!gsym->is_weak_undefined())
7261 {
7262 const Sized_symbol<32>* sym =
7263 static_cast<const Sized_symbol<32>*>(gsym);
7264 value = sym->value();
7265 }
7266 else
7267 value = 0;
7268 }
7269
7270 unsigned got_offset = reloc.got_offset();
7271 gold_assert(got_offset < oview_size);
7272
7273 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7274 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7275 Valtype x;
7276 switch (reloc.r_type())
7277 {
7278 case elfcpp::R_ARM_TLS_DTPOFF32:
7279 x = value;
7280 break;
7281 case elfcpp::R_ARM_TLS_TPOFF32:
7282 x = value + aligned_tcb_size;
7283 break;
7284 default:
7285 gold_unreachable();
7286 }
7287 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7288 }
7289
7290 of->write_output_view(offset, oview_size, oview);
7291 }
7292
7293 // A class to handle the PLT data.
7294 // This is an abstract base class that handles most of the linker details
7295 // but does not know the actual contents of PLT entries. The derived
7296 // classes below fill in those details.
7297
7298 template<bool big_endian>
7299 class Output_data_plt_arm : public Output_section_data
7300 {
7301 public:
7302 // Unlike aarch64, which records symbol value in "addend" field of relocations
7303 // and could be done at the same time an IRelative reloc is created for the
7304 // symbol, arm puts the symbol value into "GOT" table, which, however, is
7305 // issued later in Output_data_plt_arm::do_write(). So we have a struct here
7306 // to keep necessary symbol information for later use in do_write. We usually
7307 // have only a very limited number of ifuncs, so the extra data required here
7308 // is also limited.
7309
7310 struct IRelative_data
7311 {
7312 IRelative_data(Sized_symbol<32>* sized_symbol)
7313 : symbol_is_global_(true)
7314 {
7315 u_.global = sized_symbol;
7316 }
7317
7318 IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
7319 unsigned int index)
7320 : symbol_is_global_(false)
7321 {
7322 u_.local.relobj = relobj;
7323 u_.local.index = index;
7324 }
7325
7326 union
7327 {
7328 Sized_symbol<32>* global;
7329
7330 struct
7331 {
7332 Sized_relobj_file<32, big_endian>* relobj;
7333 unsigned int index;
7334 } local;
7335 } u_;
7336
7337 bool symbol_is_global_;
7338 };
7339
7340 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7341 Reloc_section;
7342
7343 Output_data_plt_arm(Layout* layout, uint64_t addralign,
7344 Arm_output_data_got<big_endian>* got,
7345 Output_data_space* got_plt,
7346 Output_data_space* got_irelative);
7347
7348 // Add an entry to the PLT.
7349 void
7350 add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
7351
7352 // Add the relocation for a plt entry.
7353 void
7354 add_relocation(Symbol_table* symtab, Layout* layout,
7355 Symbol* gsym, unsigned int got_offset);
7356
7357 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
7358 unsigned int
7359 add_local_ifunc_entry(Symbol_table* symtab, Layout*,
7360 Sized_relobj_file<32, big_endian>* relobj,
7361 unsigned int local_sym_index);
7362
7363 // Return the .rel.plt section data.
7364 const Reloc_section*
7365 rel_plt() const
7366 { return this->rel_; }
7367
7368 // Return the PLT relocation container for IRELATIVE.
7369 Reloc_section*
7370 rel_irelative(Symbol_table*, Layout*);
7371
7372 // Return the number of PLT entries.
7373 unsigned int
7374 entry_count() const
7375 { return this->count_ + this->irelative_count_; }
7376
7377 // Return the offset of the first non-reserved PLT entry.
7378 unsigned int
7379 first_plt_entry_offset() const
7380 { return this->do_first_plt_entry_offset(); }
7381
7382 // Return the size of a PLT entry.
7383 unsigned int
7384 get_plt_entry_size() const
7385 { return this->do_get_plt_entry_size(); }
7386
7387 // Return the PLT address for globals.
7388 uint32_t
7389 address_for_global(const Symbol*) const;
7390
7391 // Return the PLT address for locals.
7392 uint32_t
7393 address_for_local(const Relobj*, unsigned int symndx) const;
7394
7395 protected:
7396 // Fill in the first PLT entry.
7397 void
7398 fill_first_plt_entry(unsigned char* pov,
7399 Arm_address got_address,
7400 Arm_address plt_address)
7401 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7402
7403 void
7404 fill_plt_entry(unsigned char* pov,
7405 Arm_address got_address,
7406 Arm_address plt_address,
7407 unsigned int got_offset,
7408 unsigned int plt_offset)
7409 { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7410
7411 virtual unsigned int
7412 do_first_plt_entry_offset() const = 0;
7413
7414 virtual unsigned int
7415 do_get_plt_entry_size() const = 0;
7416
7417 virtual void
7418 do_fill_first_plt_entry(unsigned char* pov,
7419 Arm_address got_address,
7420 Arm_address plt_address) = 0;
7421
7422 virtual void
7423 do_fill_plt_entry(unsigned char* pov,
7424 Arm_address got_address,
7425 Arm_address plt_address,
7426 unsigned int got_offset,
7427 unsigned int plt_offset) = 0;
7428
7429 void
7430 do_adjust_output_section(Output_section* os);
7431
7432 // Write to a map file.
7433 void
7434 do_print_to_mapfile(Mapfile* mapfile) const
7435 { mapfile->print_output_data(this, _("** PLT")); }
7436
7437 private:
7438 // Set the final size.
7439 void
7440 set_final_data_size()
7441 {
7442 this->set_data_size(this->first_plt_entry_offset()
7443 + ((this->count_ + this->irelative_count_)
7444 * this->get_plt_entry_size()));
7445 }
7446
7447 // Write out the PLT data.
7448 void
7449 do_write(Output_file*);
7450
7451 // Record irelative symbol data.
7452 void insert_irelative_data(const IRelative_data& idata)
7453 { irelative_data_vec_.push_back(idata); }
7454
7455 // The reloc section.
7456 Reloc_section* rel_;
7457 // The IRELATIVE relocs, if necessary. These must follow the
7458 // regular PLT relocations.
7459 Reloc_section* irelative_rel_;
7460 // The .got section.
7461 Arm_output_data_got<big_endian>* got_;
7462 // The .got.plt section.
7463 Output_data_space* got_plt_;
7464 // The part of the .got.plt section used for IRELATIVE relocs.
7465 Output_data_space* got_irelative_;
7466 // The number of PLT entries.
7467 unsigned int count_;
7468 // Number of PLT entries with R_ARM_IRELATIVE relocs. These
7469 // follow the regular PLT entries.
7470 unsigned int irelative_count_;
7471 // Vector for irelative data.
7472 typedef std::vector<IRelative_data> IRelative_data_vec;
7473 IRelative_data_vec irelative_data_vec_;
7474 };
7475
7476 // Create the PLT section. The ordinary .got section is an argument,
7477 // since we need to refer to the start. We also create our own .got
7478 // section just for PLT entries.
7479
7480 template<bool big_endian>
7481 Output_data_plt_arm<big_endian>::Output_data_plt_arm(
7482 Layout* layout, uint64_t addralign,
7483 Arm_output_data_got<big_endian>* got,
7484 Output_data_space* got_plt,
7485 Output_data_space* got_irelative)
7486 : Output_section_data(addralign), irelative_rel_(NULL),
7487 got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
7488 count_(0), irelative_count_(0)
7489 {
7490 this->rel_ = new Reloc_section(false);
7491 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7492 elfcpp::SHF_ALLOC, this->rel_,
7493 ORDER_DYNAMIC_PLT_RELOCS, false);
7494 }
7495
7496 template<bool big_endian>
7497 void
7498 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7499 {
7500 os->set_entsize(0);
7501 }
7502
7503 // Add an entry to the PLT.
7504
7505 template<bool big_endian>
7506 void
7507 Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
7508 Layout* layout,
7509 Symbol* gsym)
7510 {
7511 gold_assert(!gsym->has_plt_offset());
7512
7513 unsigned int* entry_count;
7514 Output_section_data_build* got;
7515
7516 // We have 2 different types of plt entry here, normal and ifunc.
7517
7518 // For normal plt, the offset begins with first_plt_entry_offset(20), and the
7519 // 1st entry offset would be 20, the second 32, third 44 ... etc.
7520
7521 // For ifunc plt, the offset begins with 0. So the first offset would 0,
7522 // second 12, third 24 ... etc.
7523
7524 // IFunc plt entries *always* come after *normal* plt entries.
7525
7526 // Notice, when computing the plt address of a certain symbol, "plt_address +
7527 // plt_offset" is no longer correct. Use target->plt_address_for_global() or
7528 // target->plt_address_for_local() instead.
7529
7530 int begin_offset = 0;
7531 if (gsym->type() == elfcpp::STT_GNU_IFUNC
7532 && gsym->can_use_relative_reloc(false))
7533 {
7534 entry_count = &this->irelative_count_;
7535 got = this->got_irelative_;
7536 // For irelative plt entries, offset is relative to the end of normal plt
7537 // entries, so it starts from 0.
7538 begin_offset = 0;
7539 // Record symbol information.
7540 this->insert_irelative_data(
7541 IRelative_data(symtab->get_sized_symbol<32>(gsym)));
7542 }
7543 else
7544 {
7545 entry_count = &this->count_;
7546 got = this->got_plt_;
7547 // Note that for normal plt entries, when setting the PLT offset we skip
7548 // the initial reserved PLT entry.
7549 begin_offset = this->first_plt_entry_offset();
7550 }
7551
7552 gsym->set_plt_offset(begin_offset
7553 + (*entry_count) * this->get_plt_entry_size());
7554
7555 ++(*entry_count);
7556
7557 section_offset_type got_offset = got->current_data_size();
7558
7559 // Every PLT entry needs a GOT entry which points back to the PLT
7560 // entry (this will be changed by the dynamic linker, normally
7561 // lazily when the function is called).
7562 got->set_current_data_size(got_offset + 4);
7563
7564 // Every PLT entry needs a reloc.
7565 this->add_relocation(symtab, layout, gsym, got_offset);
7566
7567 // Note that we don't need to save the symbol. The contents of the
7568 // PLT are independent of which symbols are used. The symbols only
7569 // appear in the relocations.
7570 }
7571
7572 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
7573 // the PLT offset.
7574
7575 template<bool big_endian>
7576 unsigned int
7577 Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
7578 Symbol_table* symtab,
7579 Layout* layout,
7580 Sized_relobj_file<32, big_endian>* relobj,
7581 unsigned int local_sym_index)
7582 {
7583 this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
7584
7585 // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
7586 // no longer correct. Use target->plt_address_for_local() instead.
7587 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
7588 ++this->irelative_count_;
7589
7590 section_offset_type got_offset = this->got_irelative_->current_data_size();
7591
7592 // Every PLT entry needs a GOT entry which points back to the PLT
7593 // entry.
7594 this->got_irelative_->set_current_data_size(got_offset + 4);
7595
7596
7597 // Every PLT entry needs a reloc.
7598 Reloc_section* rel = this->rel_irelative(symtab, layout);
7599 rel->add_symbolless_local_addend(relobj, local_sym_index,
7600 elfcpp::R_ARM_IRELATIVE,
7601 this->got_irelative_, got_offset);
7602 return plt_offset;
7603 }
7604
7605
7606 // Add the relocation for a PLT entry.
7607
7608 template<bool big_endian>
7609 void
7610 Output_data_plt_arm<big_endian>::add_relocation(
7611 Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
7612 {
7613 if (gsym->type() == elfcpp::STT_GNU_IFUNC
7614 && gsym->can_use_relative_reloc(false))
7615 {
7616 Reloc_section* rel = this->rel_irelative(symtab, layout);
7617 rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
7618 this->got_irelative_, got_offset);
7619 }
7620 else
7621 {
7622 gsym->set_needs_dynsym_entry();
7623 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7624 got_offset);
7625 }
7626 }
7627
7628
7629 // Create the irelative relocation data.
7630
7631 template<bool big_endian>
7632 typename Output_data_plt_arm<big_endian>::Reloc_section*
7633 Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
7634 Layout* layout)
7635 {
7636 if (this->irelative_rel_ == NULL)
7637 {
7638 // Since irelative relocations goes into 'rel.dyn', we delegate the
7639 // creation of irelative_rel_ to where rel_dyn section gets created.
7640 Target_arm<big_endian>* arm_target =
7641 Target_arm<big_endian>::default_target();
7642 this->irelative_rel_ = arm_target->rel_irelative_section(layout);
7643
7644 // Make sure we have a place for the TLSDESC relocations, in
7645 // case we see any later on.
7646 // this->rel_tlsdesc(layout);
7647 if (parameters->doing_static_link())
7648 {
7649 // A statically linked executable will only have a .rel.plt section to
7650 // hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols. The library
7651 // will use these symbols to locate the IRELATIVE relocs at program
7652 // startup time.
7653 symtab->define_in_output_data("__rel_iplt_start", NULL,
7654 Symbol_table::PREDEFINED,
7655 this->irelative_rel_, 0, 0,
7656 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7657 elfcpp::STV_HIDDEN, 0, false, true);
7658 symtab->define_in_output_data("__rel_iplt_end", NULL,
7659 Symbol_table::PREDEFINED,
7660 this->irelative_rel_, 0, 0,
7661 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7662 elfcpp::STV_HIDDEN, 0, true, true);
7663 }
7664 }
7665 return this->irelative_rel_;
7666 }
7667
7668
7669 // Return the PLT address for a global symbol.
7670
7671 template<bool big_endian>
7672 uint32_t
7673 Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
7674 {
7675 uint64_t begin_offset = 0;
7676 if (gsym->type() == elfcpp::STT_GNU_IFUNC
7677 && gsym->can_use_relative_reloc(false))
7678 {
7679 begin_offset = (this->first_plt_entry_offset() +
7680 this->count_ * this->get_plt_entry_size());
7681 }
7682 return this->address() + begin_offset + gsym->plt_offset();
7683 }
7684
7685
7686 // Return the PLT address for a local symbol. These are always
7687 // IRELATIVE relocs.
7688
7689 template<bool big_endian>
7690 uint32_t
7691 Output_data_plt_arm<big_endian>::address_for_local(
7692 const Relobj* object,
7693 unsigned int r_sym) const
7694 {
7695 return (this->address()
7696 + this->first_plt_entry_offset()
7697 + this->count_ * this->get_plt_entry_size()
7698 + object->local_plt_offset(r_sym));
7699 }
7700
7701
7702 template<bool big_endian>
7703 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7704 {
7705 public:
7706 Output_data_plt_arm_standard(Layout* layout,
7707 Arm_output_data_got<big_endian>* got,
7708 Output_data_space* got_plt,
7709 Output_data_space* got_irelative)
7710 : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
7711 { }
7712
7713 protected:
7714 // Return the offset of the first non-reserved PLT entry.
7715 virtual unsigned int
7716 do_first_plt_entry_offset() const
7717 { return sizeof(first_plt_entry); }
7718
7719 // Return the size of a PLT entry.
7720 virtual unsigned int
7721 do_get_plt_entry_size() const
7722 { return sizeof(plt_entry); }
7723
7724 virtual void
7725 do_fill_first_plt_entry(unsigned char* pov,
7726 Arm_address got_address,
7727 Arm_address plt_address);
7728
7729 virtual void
7730 do_fill_plt_entry(unsigned char* pov,
7731 Arm_address got_address,
7732 Arm_address plt_address,
7733 unsigned int got_offset,
7734 unsigned int plt_offset);
7735
7736 private:
7737 // Template for the first PLT entry.
7738 static const uint32_t first_plt_entry[5];
7739
7740 // Template for subsequent PLT entries.
7741 static const uint32_t plt_entry[3];
7742 };
7743
7744 // ARM PLTs.
7745 // FIXME: This is not very flexible. Right now this has only been tested
7746 // on armv5te. If we are to support additional architecture features like
7747 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7748
7749 // The first entry in the PLT.
7750 template<bool big_endian>
7751 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7752 {
7753 0xe52de004, // str lr, [sp, #-4]!
7754 0xe59fe004, // ldr lr, [pc, #4]
7755 0xe08fe00e, // add lr, pc, lr
7756 0xe5bef008, // ldr pc, [lr, #8]!
7757 0x00000000, // &GOT[0] - .
7758 };
7759
7760 template<bool big_endian>
7761 void
7762 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7763 unsigned char* pov,
7764 Arm_address got_address,
7765 Arm_address plt_address)
7766 {
7767 // Write first PLT entry. All but the last word are constants.
7768 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7769 / sizeof(plt_entry[0]));
7770 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7771 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7772 // Last word in first PLT entry is &GOT[0] - .
7773 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7774 got_address - (plt_address + 16));
7775 }
7776
7777 // Subsequent entries in the PLT.
7778
7779 template<bool big_endian>
7780 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7781 {
7782 0xe28fc600, // add ip, pc, #0xNN00000
7783 0xe28cca00, // add ip, ip, #0xNN000
7784 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7785 };
7786
7787 template<bool big_endian>
7788 void
7789 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7790 unsigned char* pov,
7791 Arm_address got_address,
7792 Arm_address plt_address,
7793 unsigned int got_offset,
7794 unsigned int plt_offset)
7795 {
7796 int32_t offset = ((got_address + got_offset)
7797 - (plt_address + plt_offset + 8));
7798
7799 gold_assert(offset >= 0 && offset < 0x0fffffff);
7800 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7801 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7802 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7803 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7804 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7805 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7806 }
7807
7808 // Write out the PLT. This uses the hand-coded instructions above,
7809 // and adjusts them as needed. This is all specified by the arm ELF
7810 // Processor Supplement.
7811
7812 template<bool big_endian>
7813 void
7814 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7815 {
7816 const off_t offset = this->offset();
7817 const section_size_type oview_size =
7818 convert_to_section_size_type(this->data_size());
7819 unsigned char* const oview = of->get_output_view(offset, oview_size);
7820
7821 const off_t got_file_offset = this->got_plt_->offset();
7822 gold_assert(got_file_offset + this->got_plt_->data_size()
7823 == this->got_irelative_->offset());
7824 const section_size_type got_size =
7825 convert_to_section_size_type(this->got_plt_->data_size()
7826 + this->got_irelative_->data_size());
7827 unsigned char* const got_view = of->get_output_view(got_file_offset,
7828 got_size);
7829 unsigned char* pov = oview;
7830
7831 Arm_address plt_address = this->address();
7832 Arm_address got_address = this->got_plt_->address();
7833
7834 // Write first PLT entry.
7835 this->fill_first_plt_entry(pov, got_address, plt_address);
7836 pov += this->first_plt_entry_offset();
7837
7838 unsigned char* got_pov = got_view;
7839
7840 memset(got_pov, 0, 12);
7841 got_pov += 12;
7842
7843 unsigned int plt_offset = this->first_plt_entry_offset();
7844 unsigned int got_offset = 12;
7845 const unsigned int count = this->count_ + this->irelative_count_;
7846 gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
7847 for (unsigned int i = 0;
7848 i < count;
7849 ++i,
7850 pov += this->get_plt_entry_size(),
7851 got_pov += 4,
7852 plt_offset += this->get_plt_entry_size(),
7853 got_offset += 4)
7854 {
7855 // Set and adjust the PLT entry itself.
7856 this->fill_plt_entry(pov, got_address, plt_address,
7857 got_offset, plt_offset);
7858
7859 Arm_address value;
7860 if (i < this->count_)
7861 {
7862 // For non-irelative got entries, the value is the beginning of plt.
7863 value = plt_address;
7864 }
7865 else
7866 {
7867 // For irelative got entries, the value is the (global/local) symbol
7868 // address.
7869 const IRelative_data& idata =
7870 this->irelative_data_vec_[i - this->count_];
7871 if (idata.symbol_is_global_)
7872 {
7873 // Set the entry in the GOT for irelative symbols. The content is
7874 // the address of the ifunc, not the address of plt start.
7875 const Sized_symbol<32>* sized_symbol = idata.u_.global;
7876 gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
7877 value = sized_symbol->value();
7878 }
7879 else
7880 {
7881 value = idata.u_.local.relobj->local_symbol_value(
7882 idata.u_.local.index, 0);
7883 }
7884 }
7885 elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
7886 }
7887
7888 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7889 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7890
7891 of->write_output_view(offset, oview_size, oview);
7892 of->write_output_view(got_file_offset, got_size, got_view);
7893 }
7894
7895
7896 // Create a PLT entry for a global symbol.
7897
7898 template<bool big_endian>
7899 void
7900 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7901 Symbol* gsym)
7902 {
7903 if (gsym->has_plt_offset())
7904 return;
7905
7906 if (this->plt_ == NULL)
7907 this->make_plt_section(symtab, layout);
7908
7909 this->plt_->add_entry(symtab, layout, gsym);
7910 }
7911
7912
7913 // Create the PLT section.
7914 template<bool big_endian>
7915 void
7916 Target_arm<big_endian>::make_plt_section(
7917 Symbol_table* symtab, Layout* layout)
7918 {
7919 if (this->plt_ == NULL)
7920 {
7921 // Create the GOT section first.
7922 this->got_section(symtab, layout);
7923
7924 // GOT for irelatives is create along with got.plt.
7925 gold_assert(this->got_ != NULL
7926 && this->got_plt_ != NULL
7927 && this->got_irelative_ != NULL);
7928 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
7929 this->got_irelative_);
7930
7931 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7932 (elfcpp::SHF_ALLOC
7933 | elfcpp::SHF_EXECINSTR),
7934 this->plt_, ORDER_PLT, false);
7935 symtab->define_in_output_data("$a", NULL,
7936 Symbol_table::PREDEFINED,
7937 this->plt_,
7938 0, 0, elfcpp::STT_NOTYPE,
7939 elfcpp::STB_LOCAL,
7940 elfcpp::STV_DEFAULT, 0,
7941 false, false);
7942 }
7943 }
7944
7945
7946 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
7947
7948 template<bool big_endian>
7949 void
7950 Target_arm<big_endian>::make_local_ifunc_plt_entry(
7951 Symbol_table* symtab, Layout* layout,
7952 Sized_relobj_file<32, big_endian>* relobj,
7953 unsigned int local_sym_index)
7954 {
7955 if (relobj->local_has_plt_offset(local_sym_index))
7956 return;
7957 if (this->plt_ == NULL)
7958 this->make_plt_section(symtab, layout);
7959 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
7960 relobj,
7961 local_sym_index);
7962 relobj->set_local_plt_offset(local_sym_index, plt_offset);
7963 }
7964
7965
7966 // Return the number of entries in the PLT.
7967
7968 template<bool big_endian>
7969 unsigned int
7970 Target_arm<big_endian>::plt_entry_count() const
7971 {
7972 if (this->plt_ == NULL)
7973 return 0;
7974 return this->plt_->entry_count();
7975 }
7976
7977 // Return the offset of the first non-reserved PLT entry.
7978
7979 template<bool big_endian>
7980 unsigned int
7981 Target_arm<big_endian>::first_plt_entry_offset() const
7982 {
7983 return this->plt_->first_plt_entry_offset();
7984 }
7985
7986 // Return the size of each PLT entry.
7987
7988 template<bool big_endian>
7989 unsigned int
7990 Target_arm<big_endian>::plt_entry_size() const
7991 {
7992 return this->plt_->get_plt_entry_size();
7993 }
7994
7995 // Get the section to use for TLS_DESC relocations.
7996
7997 template<bool big_endian>
7998 typename Target_arm<big_endian>::Reloc_section*
7999 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
8000 {
8001 return this->plt_section()->rel_tls_desc(layout);
8002 }
8003
8004 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
8005
8006 template<bool big_endian>
8007 void
8008 Target_arm<big_endian>::define_tls_base_symbol(
8009 Symbol_table* symtab,
8010 Layout* layout)
8011 {
8012 if (this->tls_base_symbol_defined_)
8013 return;
8014
8015 Output_segment* tls_segment = layout->tls_segment();
8016 if (tls_segment != NULL)
8017 {
8018 bool is_exec = parameters->options().output_is_executable();
8019 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
8020 Symbol_table::PREDEFINED,
8021 tls_segment, 0, 0,
8022 elfcpp::STT_TLS,
8023 elfcpp::STB_LOCAL,
8024 elfcpp::STV_HIDDEN, 0,
8025 (is_exec
8026 ? Symbol::SEGMENT_END
8027 : Symbol::SEGMENT_START),
8028 true);
8029 }
8030 this->tls_base_symbol_defined_ = true;
8031 }
8032
8033 // Create a GOT entry for the TLS module index.
8034
8035 template<bool big_endian>
8036 unsigned int
8037 Target_arm<big_endian>::got_mod_index_entry(
8038 Symbol_table* symtab,
8039 Layout* layout,
8040 Sized_relobj_file<32, big_endian>* object)
8041 {
8042 if (this->got_mod_index_offset_ == -1U)
8043 {
8044 gold_assert(symtab != NULL && layout != NULL && object != NULL);
8045 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
8046 unsigned int got_offset;
8047 if (!parameters->doing_static_link())
8048 {
8049 got_offset = got->add_constant(0);
8050 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
8051 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
8052 got_offset);
8053 }
8054 else
8055 {
8056 // We are doing a static link. Just mark it as belong to module 1,
8057 // the executable.
8058 got_offset = got->add_constant(1);
8059 }
8060
8061 got->add_constant(0);
8062 this->got_mod_index_offset_ = got_offset;
8063 }
8064 return this->got_mod_index_offset_;
8065 }
8066
8067 // Optimize the TLS relocation type based on what we know about the
8068 // symbol. IS_FINAL is true if the final address of this symbol is
8069 // known at link time.
8070
8071 template<bool big_endian>
8072 tls::Tls_optimization
8073 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
8074 {
8075 // FIXME: Currently we do not do any TLS optimization.
8076 return tls::TLSOPT_NONE;
8077 }
8078
8079 // Get the Reference_flags for a particular relocation.
8080
8081 template<bool big_endian>
8082 int
8083 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
8084 {
8085 switch (r_type)
8086 {
8087 case elfcpp::R_ARM_NONE:
8088 case elfcpp::R_ARM_V4BX:
8089 case elfcpp::R_ARM_GNU_VTENTRY:
8090 case elfcpp::R_ARM_GNU_VTINHERIT:
8091 // No symbol reference.
8092 return 0;
8093
8094 case elfcpp::R_ARM_ABS32:
8095 case elfcpp::R_ARM_ABS16:
8096 case elfcpp::R_ARM_ABS12:
8097 case elfcpp::R_ARM_THM_ABS5:
8098 case elfcpp::R_ARM_ABS8:
8099 case elfcpp::R_ARM_BASE_ABS:
8100 case elfcpp::R_ARM_MOVW_ABS_NC:
8101 case elfcpp::R_ARM_MOVT_ABS:
8102 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8103 case elfcpp::R_ARM_THM_MOVT_ABS:
8104 case elfcpp::R_ARM_ABS32_NOI:
8105 return Symbol::ABSOLUTE_REF;
8106
8107 case elfcpp::R_ARM_REL32:
8108 case elfcpp::R_ARM_LDR_PC_G0:
8109 case elfcpp::R_ARM_SBREL32:
8110 case elfcpp::R_ARM_THM_PC8:
8111 case elfcpp::R_ARM_BASE_PREL:
8112 case elfcpp::R_ARM_MOVW_PREL_NC:
8113 case elfcpp::R_ARM_MOVT_PREL:
8114 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8115 case elfcpp::R_ARM_THM_MOVT_PREL:
8116 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8117 case elfcpp::R_ARM_THM_PC12:
8118 case elfcpp::R_ARM_REL32_NOI:
8119 case elfcpp::R_ARM_ALU_PC_G0_NC:
8120 case elfcpp::R_ARM_ALU_PC_G0:
8121 case elfcpp::R_ARM_ALU_PC_G1_NC:
8122 case elfcpp::R_ARM_ALU_PC_G1:
8123 case elfcpp::R_ARM_ALU_PC_G2:
8124 case elfcpp::R_ARM_LDR_PC_G1:
8125 case elfcpp::R_ARM_LDR_PC_G2:
8126 case elfcpp::R_ARM_LDRS_PC_G0:
8127 case elfcpp::R_ARM_LDRS_PC_G1:
8128 case elfcpp::R_ARM_LDRS_PC_G2:
8129 case elfcpp::R_ARM_LDC_PC_G0:
8130 case elfcpp::R_ARM_LDC_PC_G1:
8131 case elfcpp::R_ARM_LDC_PC_G2:
8132 case elfcpp::R_ARM_ALU_SB_G0_NC:
8133 case elfcpp::R_ARM_ALU_SB_G0:
8134 case elfcpp::R_ARM_ALU_SB_G1_NC:
8135 case elfcpp::R_ARM_ALU_SB_G1:
8136 case elfcpp::R_ARM_ALU_SB_G2:
8137 case elfcpp::R_ARM_LDR_SB_G0:
8138 case elfcpp::R_ARM_LDR_SB_G1:
8139 case elfcpp::R_ARM_LDR_SB_G2:
8140 case elfcpp::R_ARM_LDRS_SB_G0:
8141 case elfcpp::R_ARM_LDRS_SB_G1:
8142 case elfcpp::R_ARM_LDRS_SB_G2:
8143 case elfcpp::R_ARM_LDC_SB_G0:
8144 case elfcpp::R_ARM_LDC_SB_G1:
8145 case elfcpp::R_ARM_LDC_SB_G2:
8146 case elfcpp::R_ARM_MOVW_BREL_NC:
8147 case elfcpp::R_ARM_MOVT_BREL:
8148 case elfcpp::R_ARM_MOVW_BREL:
8149 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8150 case elfcpp::R_ARM_THM_MOVT_BREL:
8151 case elfcpp::R_ARM_THM_MOVW_BREL:
8152 case elfcpp::R_ARM_GOTOFF32:
8153 case elfcpp::R_ARM_GOTOFF12:
8154 case elfcpp::R_ARM_SBREL31:
8155 return Symbol::RELATIVE_REF;
8156
8157 case elfcpp::R_ARM_PLT32:
8158 case elfcpp::R_ARM_CALL:
8159 case elfcpp::R_ARM_JUMP24:
8160 case elfcpp::R_ARM_THM_CALL:
8161 case elfcpp::R_ARM_THM_JUMP24:
8162 case elfcpp::R_ARM_THM_JUMP19:
8163 case elfcpp::R_ARM_THM_JUMP6:
8164 case elfcpp::R_ARM_THM_JUMP11:
8165 case elfcpp::R_ARM_THM_JUMP8:
8166 // R_ARM_PREL31 is not used to relocate call/jump instructions but
8167 // in unwind tables. It may point to functions via PLTs.
8168 // So we treat it like call/jump relocations above.
8169 case elfcpp::R_ARM_PREL31:
8170 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
8171
8172 case elfcpp::R_ARM_GOT_BREL:
8173 case elfcpp::R_ARM_GOT_ABS:
8174 case elfcpp::R_ARM_GOT_PREL:
8175 // Absolute in GOT.
8176 return Symbol::ABSOLUTE_REF;
8177
8178 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8179 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8180 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8181 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8182 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8183 return Symbol::TLS_REF;
8184
8185 case elfcpp::R_ARM_TARGET1:
8186 case elfcpp::R_ARM_TARGET2:
8187 case elfcpp::R_ARM_COPY:
8188 case elfcpp::R_ARM_GLOB_DAT:
8189 case elfcpp::R_ARM_JUMP_SLOT:
8190 case elfcpp::R_ARM_RELATIVE:
8191 case elfcpp::R_ARM_PC24:
8192 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8193 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8194 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8195 default:
8196 // Not expected. We will give an error later.
8197 return 0;
8198 }
8199 }
8200
8201 // Report an unsupported relocation against a local symbol.
8202
8203 template<bool big_endian>
8204 void
8205 Target_arm<big_endian>::Scan::unsupported_reloc_local(
8206 Sized_relobj_file<32, big_endian>* object,
8207 unsigned int r_type)
8208 {
8209 gold_error(_("%s: unsupported reloc %u against local symbol"),
8210 object->name().c_str(), r_type);
8211 }
8212
8213 // We are about to emit a dynamic relocation of type R_TYPE. If the
8214 // dynamic linker does not support it, issue an error. The GNU linker
8215 // only issues a non-PIC error for an allocated read-only section.
8216 // Here we know the section is allocated, but we don't know that it is
8217 // read-only. But we check for all the relocation types which the
8218 // glibc dynamic linker supports, so it seems appropriate to issue an
8219 // error even if the section is not read-only.
8220
8221 template<bool big_endian>
8222 void
8223 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
8224 unsigned int r_type)
8225 {
8226 switch (r_type)
8227 {
8228 // These are the relocation types supported by glibc for ARM.
8229 case elfcpp::R_ARM_RELATIVE:
8230 case elfcpp::R_ARM_COPY:
8231 case elfcpp::R_ARM_GLOB_DAT:
8232 case elfcpp::R_ARM_JUMP_SLOT:
8233 case elfcpp::R_ARM_ABS32:
8234 case elfcpp::R_ARM_ABS32_NOI:
8235 case elfcpp::R_ARM_IRELATIVE:
8236 case elfcpp::R_ARM_PC24:
8237 // FIXME: The following 3 types are not supported by Android's dynamic
8238 // linker.
8239 case elfcpp::R_ARM_TLS_DTPMOD32:
8240 case elfcpp::R_ARM_TLS_DTPOFF32:
8241 case elfcpp::R_ARM_TLS_TPOFF32:
8242 return;
8243
8244 default:
8245 {
8246 // This prevents us from issuing more than one error per reloc
8247 // section. But we can still wind up issuing more than one
8248 // error per object file.
8249 if (this->issued_non_pic_error_)
8250 return;
8251 const Arm_reloc_property* reloc_property =
8252 arm_reloc_property_table->get_reloc_property(r_type);
8253 gold_assert(reloc_property != NULL);
8254 object->error(_("requires unsupported dynamic reloc %s; "
8255 "recompile with -fPIC"),
8256 reloc_property->name().c_str());
8257 this->issued_non_pic_error_ = true;
8258 return;
8259 }
8260
8261 case elfcpp::R_ARM_NONE:
8262 gold_unreachable();
8263 }
8264 }
8265
8266
8267 // Return whether we need to make a PLT entry for a relocation of the
8268 // given type against a STT_GNU_IFUNC symbol.
8269
8270 template<bool big_endian>
8271 bool
8272 Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
8273 Sized_relobj_file<32, big_endian>* object,
8274 unsigned int r_type)
8275 {
8276 int flags = Scan::get_reference_flags(r_type);
8277 if (flags & Symbol::TLS_REF)
8278 {
8279 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
8280 object->name().c_str(), r_type);
8281 return false;
8282 }
8283 return flags != 0;
8284 }
8285
8286
8287 // Scan a relocation for a local symbol.
8288 // FIXME: This only handles a subset of relocation types used by Android
8289 // on ARM v5te devices.
8290
8291 template<bool big_endian>
8292 inline void
8293 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
8294 Layout* layout,
8295 Target_arm* target,
8296 Sized_relobj_file<32, big_endian>* object,
8297 unsigned int data_shndx,
8298 Output_section* output_section,
8299 const elfcpp::Rel<32, big_endian>& reloc,
8300 unsigned int r_type,
8301 const elfcpp::Sym<32, big_endian>& lsym,
8302 bool is_discarded)
8303 {
8304 if (is_discarded)
8305 return;
8306
8307 r_type = get_real_reloc_type(r_type);
8308
8309 // A local STT_GNU_IFUNC symbol may require a PLT entry.
8310 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
8311 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
8312 {
8313 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8314 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
8315 }
8316
8317 switch (r_type)
8318 {
8319 case elfcpp::R_ARM_NONE:
8320 case elfcpp::R_ARM_V4BX:
8321 case elfcpp::R_ARM_GNU_VTENTRY:
8322 case elfcpp::R_ARM_GNU_VTINHERIT:
8323 break;
8324
8325 case elfcpp::R_ARM_ABS32:
8326 case elfcpp::R_ARM_ABS32_NOI:
8327 // If building a shared library (or a position-independent
8328 // executable), we need to create a dynamic relocation for
8329 // this location. The relocation applied at link time will
8330 // apply the link-time value, so we flag the location with
8331 // an R_ARM_RELATIVE relocation so the dynamic loader can
8332 // relocate it easily.
8333 if (parameters->options().output_is_position_independent())
8334 {
8335 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8336 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8337 // If we are to add more other reloc types than R_ARM_ABS32,
8338 // we need to add check_non_pic(object, r_type) here.
8339 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
8340 output_section, data_shndx,
8341 reloc.get_r_offset(), is_ifunc);
8342 }
8343 break;
8344
8345 case elfcpp::R_ARM_ABS16:
8346 case elfcpp::R_ARM_ABS12:
8347 case elfcpp::R_ARM_THM_ABS5:
8348 case elfcpp::R_ARM_ABS8:
8349 case elfcpp::R_ARM_BASE_ABS:
8350 case elfcpp::R_ARM_MOVW_ABS_NC:
8351 case elfcpp::R_ARM_MOVT_ABS:
8352 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8353 case elfcpp::R_ARM_THM_MOVT_ABS:
8354 // If building a shared library (or a position-independent
8355 // executable), we need to create a dynamic relocation for
8356 // this location. Because the addend needs to remain in the
8357 // data section, we need to be careful not to apply this
8358 // relocation statically.
8359 if (parameters->options().output_is_position_independent())
8360 {
8361 check_non_pic(object, r_type);
8362 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8363 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8364 if (lsym.get_st_type() != elfcpp::STT_SECTION)
8365 rel_dyn->add_local(object, r_sym, r_type, output_section,
8366 data_shndx, reloc.get_r_offset());
8367 else
8368 {
8369 gold_assert(lsym.get_st_value() == 0);
8370 unsigned int shndx = lsym.get_st_shndx();
8371 bool is_ordinary;
8372 shndx = object->adjust_sym_shndx(r_sym, shndx,
8373 &is_ordinary);
8374 if (!is_ordinary)
8375 object->error(_("section symbol %u has bad shndx %u"),
8376 r_sym, shndx);
8377 else
8378 rel_dyn->add_local_section(object, shndx,
8379 r_type, output_section,
8380 data_shndx, reloc.get_r_offset());
8381 }
8382 }
8383 break;
8384
8385 case elfcpp::R_ARM_REL32:
8386 case elfcpp::R_ARM_LDR_PC_G0:
8387 case elfcpp::R_ARM_SBREL32:
8388 case elfcpp::R_ARM_THM_CALL:
8389 case elfcpp::R_ARM_THM_PC8:
8390 case elfcpp::R_ARM_BASE_PREL:
8391 case elfcpp::R_ARM_PLT32:
8392 case elfcpp::R_ARM_CALL:
8393 case elfcpp::R_ARM_JUMP24:
8394 case elfcpp::R_ARM_THM_JUMP24:
8395 case elfcpp::R_ARM_SBREL31:
8396 case elfcpp::R_ARM_PREL31:
8397 case elfcpp::R_ARM_MOVW_PREL_NC:
8398 case elfcpp::R_ARM_MOVT_PREL:
8399 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8400 case elfcpp::R_ARM_THM_MOVT_PREL:
8401 case elfcpp::R_ARM_THM_JUMP19:
8402 case elfcpp::R_ARM_THM_JUMP6:
8403 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8404 case elfcpp::R_ARM_THM_PC12:
8405 case elfcpp::R_ARM_REL32_NOI:
8406 case elfcpp::R_ARM_ALU_PC_G0_NC:
8407 case elfcpp::R_ARM_ALU_PC_G0:
8408 case elfcpp::R_ARM_ALU_PC_G1_NC:
8409 case elfcpp::R_ARM_ALU_PC_G1:
8410 case elfcpp::R_ARM_ALU_PC_G2:
8411 case elfcpp::R_ARM_LDR_PC_G1:
8412 case elfcpp::R_ARM_LDR_PC_G2:
8413 case elfcpp::R_ARM_LDRS_PC_G0:
8414 case elfcpp::R_ARM_LDRS_PC_G1:
8415 case elfcpp::R_ARM_LDRS_PC_G2:
8416 case elfcpp::R_ARM_LDC_PC_G0:
8417 case elfcpp::R_ARM_LDC_PC_G1:
8418 case elfcpp::R_ARM_LDC_PC_G2:
8419 case elfcpp::R_ARM_ALU_SB_G0_NC:
8420 case elfcpp::R_ARM_ALU_SB_G0:
8421 case elfcpp::R_ARM_ALU_SB_G1_NC:
8422 case elfcpp::R_ARM_ALU_SB_G1:
8423 case elfcpp::R_ARM_ALU_SB_G2:
8424 case elfcpp::R_ARM_LDR_SB_G0:
8425 case elfcpp::R_ARM_LDR_SB_G1:
8426 case elfcpp::R_ARM_LDR_SB_G2:
8427 case elfcpp::R_ARM_LDRS_SB_G0:
8428 case elfcpp::R_ARM_LDRS_SB_G1:
8429 case elfcpp::R_ARM_LDRS_SB_G2:
8430 case elfcpp::R_ARM_LDC_SB_G0:
8431 case elfcpp::R_ARM_LDC_SB_G1:
8432 case elfcpp::R_ARM_LDC_SB_G2:
8433 case elfcpp::R_ARM_MOVW_BREL_NC:
8434 case elfcpp::R_ARM_MOVT_BREL:
8435 case elfcpp::R_ARM_MOVW_BREL:
8436 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8437 case elfcpp::R_ARM_THM_MOVT_BREL:
8438 case elfcpp::R_ARM_THM_MOVW_BREL:
8439 case elfcpp::R_ARM_THM_JUMP11:
8440 case elfcpp::R_ARM_THM_JUMP8:
8441 // We don't need to do anything for a relative addressing relocation
8442 // against a local symbol if it does not reference the GOT.
8443 break;
8444
8445 case elfcpp::R_ARM_GOTOFF32:
8446 case elfcpp::R_ARM_GOTOFF12:
8447 // We need a GOT section:
8448 target->got_section(symtab, layout);
8449 break;
8450
8451 case elfcpp::R_ARM_GOT_BREL:
8452 case elfcpp::R_ARM_GOT_PREL:
8453 {
8454 // The symbol requires a GOT entry.
8455 Arm_output_data_got<big_endian>* got =
8456 target->got_section(symtab, layout);
8457 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8458 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8459 {
8460 // If we are generating a shared object, we need to add a
8461 // dynamic RELATIVE relocation for this symbol's GOT entry.
8462 if (parameters->options().output_is_position_independent())
8463 {
8464 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8465 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8466 rel_dyn->add_local_relative(
8467 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8468 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8469 }
8470 }
8471 }
8472 break;
8473
8474 case elfcpp::R_ARM_TARGET1:
8475 case elfcpp::R_ARM_TARGET2:
8476 // This should have been mapped to another type already.
8477 // Fall through.
8478 case elfcpp::R_ARM_COPY:
8479 case elfcpp::R_ARM_GLOB_DAT:
8480 case elfcpp::R_ARM_JUMP_SLOT:
8481 case elfcpp::R_ARM_RELATIVE:
8482 // These are relocations which should only be seen by the
8483 // dynamic linker, and should never be seen here.
8484 gold_error(_("%s: unexpected reloc %u in object file"),
8485 object->name().c_str(), r_type);
8486 break;
8487
8488
8489 // These are initial TLS relocs, which are expected when
8490 // linking.
8491 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8492 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8493 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8494 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8495 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8496 {
8497 bool output_is_shared = parameters->options().shared();
8498 const tls::Tls_optimization optimized_type
8499 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8500 r_type);
8501 switch (r_type)
8502 {
8503 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8504 if (optimized_type == tls::TLSOPT_NONE)
8505 {
8506 // Create a pair of GOT entries for the module index and
8507 // dtv-relative offset.
8508 Arm_output_data_got<big_endian>* got
8509 = target->got_section(symtab, layout);
8510 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8511 unsigned int shndx = lsym.get_st_shndx();
8512 bool is_ordinary;
8513 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8514 if (!is_ordinary)
8515 {
8516 object->error(_("local symbol %u has bad shndx %u"),
8517 r_sym, shndx);
8518 break;
8519 }
8520
8521 if (!parameters->doing_static_link())
8522 got->add_local_pair_with_rel(object, r_sym, shndx,
8523 GOT_TYPE_TLS_PAIR,
8524 target->rel_dyn_section(layout),
8525 elfcpp::R_ARM_TLS_DTPMOD32);
8526 else
8527 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8528 object, r_sym);
8529 }
8530 else
8531 // FIXME: TLS optimization not supported yet.
8532 gold_unreachable();
8533 break;
8534
8535 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8536 if (optimized_type == tls::TLSOPT_NONE)
8537 {
8538 // Create a GOT entry for the module index.
8539 target->got_mod_index_entry(symtab, layout, object);
8540 }
8541 else
8542 // FIXME: TLS optimization not supported yet.
8543 gold_unreachable();
8544 break;
8545
8546 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8547 break;
8548
8549 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8550 layout->set_has_static_tls();
8551 if (optimized_type == tls::TLSOPT_NONE)
8552 {
8553 // Create a GOT entry for the tp-relative offset.
8554 Arm_output_data_got<big_endian>* got
8555 = target->got_section(symtab, layout);
8556 unsigned int r_sym =
8557 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8558 if (!parameters->doing_static_link())
8559 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8560 target->rel_dyn_section(layout),
8561 elfcpp::R_ARM_TLS_TPOFF32);
8562 else if (!object->local_has_got_offset(r_sym,
8563 GOT_TYPE_TLS_OFFSET))
8564 {
8565 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8566 unsigned int got_offset =
8567 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8568 got->add_static_reloc(got_offset,
8569 elfcpp::R_ARM_TLS_TPOFF32, object,
8570 r_sym);
8571 }
8572 }
8573 else
8574 // FIXME: TLS optimization not supported yet.
8575 gold_unreachable();
8576 break;
8577
8578 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8579 layout->set_has_static_tls();
8580 if (output_is_shared)
8581 {
8582 // We need to create a dynamic relocation.
8583 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8584 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8585 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8586 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8587 output_section, data_shndx,
8588 reloc.get_r_offset());
8589 }
8590 break;
8591
8592 default:
8593 gold_unreachable();
8594 }
8595 }
8596 break;
8597
8598 case elfcpp::R_ARM_PC24:
8599 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8600 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8601 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8602 default:
8603 unsupported_reloc_local(object, r_type);
8604 break;
8605 }
8606 }
8607
8608 // Report an unsupported relocation against a global symbol.
8609
8610 template<bool big_endian>
8611 void
8612 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8613 Sized_relobj_file<32, big_endian>* object,
8614 unsigned int r_type,
8615 Symbol* gsym)
8616 {
8617 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8618 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8619 }
8620
8621 template<bool big_endian>
8622 inline bool
8623 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8624 unsigned int r_type)
8625 {
8626 switch (r_type)
8627 {
8628 case elfcpp::R_ARM_PC24:
8629 case elfcpp::R_ARM_THM_CALL:
8630 case elfcpp::R_ARM_PLT32:
8631 case elfcpp::R_ARM_CALL:
8632 case elfcpp::R_ARM_JUMP24:
8633 case elfcpp::R_ARM_THM_JUMP24:
8634 case elfcpp::R_ARM_SBREL31:
8635 case elfcpp::R_ARM_PREL31:
8636 case elfcpp::R_ARM_THM_JUMP19:
8637 case elfcpp::R_ARM_THM_JUMP6:
8638 case elfcpp::R_ARM_THM_JUMP11:
8639 case elfcpp::R_ARM_THM_JUMP8:
8640 // All the relocations above are branches except SBREL31 and PREL31.
8641 return false;
8642
8643 default:
8644 // Be conservative and assume this is a function pointer.
8645 return true;
8646 }
8647 }
8648
8649 template<bool big_endian>
8650 inline bool
8651 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8652 Symbol_table*,
8653 Layout*,
8654 Target_arm<big_endian>* target,
8655 Sized_relobj_file<32, big_endian>*,
8656 unsigned int,
8657 Output_section*,
8658 const elfcpp::Rel<32, big_endian>&,
8659 unsigned int r_type,
8660 const elfcpp::Sym<32, big_endian>&)
8661 {
8662 r_type = target->get_real_reloc_type(r_type);
8663 return possible_function_pointer_reloc(r_type);
8664 }
8665
8666 template<bool big_endian>
8667 inline bool
8668 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8669 Symbol_table*,
8670 Layout*,
8671 Target_arm<big_endian>* target,
8672 Sized_relobj_file<32, big_endian>*,
8673 unsigned int,
8674 Output_section*,
8675 const elfcpp::Rel<32, big_endian>&,
8676 unsigned int r_type,
8677 Symbol* gsym)
8678 {
8679 // GOT is not a function.
8680 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8681 return false;
8682
8683 r_type = target->get_real_reloc_type(r_type);
8684 return possible_function_pointer_reloc(r_type);
8685 }
8686
8687 // Scan a relocation for a global symbol.
8688
8689 template<bool big_endian>
8690 inline void
8691 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8692 Layout* layout,
8693 Target_arm* target,
8694 Sized_relobj_file<32, big_endian>* object,
8695 unsigned int data_shndx,
8696 Output_section* output_section,
8697 const elfcpp::Rel<32, big_endian>& reloc,
8698 unsigned int r_type,
8699 Symbol* gsym)
8700 {
8701 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8702 // section. We check here to avoid creating a dynamic reloc against
8703 // _GLOBAL_OFFSET_TABLE_.
8704 if (!target->has_got_section()
8705 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8706 target->got_section(symtab, layout);
8707
8708 // A STT_GNU_IFUNC symbol may require a PLT entry.
8709 if (gsym->type() == elfcpp::STT_GNU_IFUNC
8710 && this->reloc_needs_plt_for_ifunc(object, r_type))
8711 target->make_plt_entry(symtab, layout, gsym);
8712
8713 r_type = get_real_reloc_type(r_type);
8714 switch (r_type)
8715 {
8716 case elfcpp::R_ARM_NONE:
8717 case elfcpp::R_ARM_V4BX:
8718 case elfcpp::R_ARM_GNU_VTENTRY:
8719 case elfcpp::R_ARM_GNU_VTINHERIT:
8720 break;
8721
8722 case elfcpp::R_ARM_ABS32:
8723 case elfcpp::R_ARM_ABS16:
8724 case elfcpp::R_ARM_ABS12:
8725 case elfcpp::R_ARM_THM_ABS5:
8726 case elfcpp::R_ARM_ABS8:
8727 case elfcpp::R_ARM_BASE_ABS:
8728 case elfcpp::R_ARM_MOVW_ABS_NC:
8729 case elfcpp::R_ARM_MOVT_ABS:
8730 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8731 case elfcpp::R_ARM_THM_MOVT_ABS:
8732 case elfcpp::R_ARM_ABS32_NOI:
8733 // Absolute addressing relocations.
8734 {
8735 // Make a PLT entry if necessary.
8736 if (this->symbol_needs_plt_entry(gsym))
8737 {
8738 target->make_plt_entry(symtab, layout, gsym);
8739 // Since this is not a PC-relative relocation, we may be
8740 // taking the address of a function. In that case we need to
8741 // set the entry in the dynamic symbol table to the address of
8742 // the PLT entry.
8743 if (gsym->is_from_dynobj() && !parameters->options().shared())
8744 gsym->set_needs_dynsym_value();
8745 }
8746 // Make a dynamic relocation if necessary.
8747 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8748 {
8749 if (!parameters->options().output_is_position_independent()
8750 && gsym->may_need_copy_reloc())
8751 {
8752 target->copy_reloc(symtab, layout, object,
8753 data_shndx, output_section, gsym, reloc);
8754 }
8755 else if ((r_type == elfcpp::R_ARM_ABS32
8756 || r_type == elfcpp::R_ARM_ABS32_NOI)
8757 && gsym->type() == elfcpp::STT_GNU_IFUNC
8758 && gsym->can_use_relative_reloc(false)
8759 && !gsym->is_from_dynobj()
8760 && !gsym->is_undefined()
8761 && !gsym->is_preemptible())
8762 {
8763 // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
8764 // symbol. This makes a function address in a PIE executable
8765 // match the address in a shared library that it links against.
8766 Reloc_section* rel_irelative =
8767 target->rel_irelative_section(layout);
8768 unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
8769 rel_irelative->add_symbolless_global_addend(
8770 gsym, r_type, output_section, object,
8771 data_shndx, reloc.get_r_offset());
8772 }
8773 else if ((r_type == elfcpp::R_ARM_ABS32
8774 || r_type == elfcpp::R_ARM_ABS32_NOI)
8775 && gsym->can_use_relative_reloc(false))
8776 {
8777 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8778 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8779 output_section, object,
8780 data_shndx, reloc.get_r_offset());
8781 }
8782 else
8783 {
8784 check_non_pic(object, r_type);
8785 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8786 rel_dyn->add_global(gsym, r_type, output_section, object,
8787 data_shndx, reloc.get_r_offset());
8788 }
8789 }
8790 }
8791 break;
8792
8793 case elfcpp::R_ARM_GOTOFF32:
8794 case elfcpp::R_ARM_GOTOFF12:
8795 // We need a GOT section.
8796 target->got_section(symtab, layout);
8797 break;
8798
8799 case elfcpp::R_ARM_REL32:
8800 case elfcpp::R_ARM_LDR_PC_G0:
8801 case elfcpp::R_ARM_SBREL32:
8802 case elfcpp::R_ARM_THM_PC8:
8803 case elfcpp::R_ARM_BASE_PREL:
8804 case elfcpp::R_ARM_MOVW_PREL_NC:
8805 case elfcpp::R_ARM_MOVT_PREL:
8806 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8807 case elfcpp::R_ARM_THM_MOVT_PREL:
8808 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8809 case elfcpp::R_ARM_THM_PC12:
8810 case elfcpp::R_ARM_REL32_NOI:
8811 case elfcpp::R_ARM_ALU_PC_G0_NC:
8812 case elfcpp::R_ARM_ALU_PC_G0:
8813 case elfcpp::R_ARM_ALU_PC_G1_NC:
8814 case elfcpp::R_ARM_ALU_PC_G1:
8815 case elfcpp::R_ARM_ALU_PC_G2:
8816 case elfcpp::R_ARM_LDR_PC_G1:
8817 case elfcpp::R_ARM_LDR_PC_G2:
8818 case elfcpp::R_ARM_LDRS_PC_G0:
8819 case elfcpp::R_ARM_LDRS_PC_G1:
8820 case elfcpp::R_ARM_LDRS_PC_G2:
8821 case elfcpp::R_ARM_LDC_PC_G0:
8822 case elfcpp::R_ARM_LDC_PC_G1:
8823 case elfcpp::R_ARM_LDC_PC_G2:
8824 case elfcpp::R_ARM_ALU_SB_G0_NC:
8825 case elfcpp::R_ARM_ALU_SB_G0:
8826 case elfcpp::R_ARM_ALU_SB_G1_NC:
8827 case elfcpp::R_ARM_ALU_SB_G1:
8828 case elfcpp::R_ARM_ALU_SB_G2:
8829 case elfcpp::R_ARM_LDR_SB_G0:
8830 case elfcpp::R_ARM_LDR_SB_G1:
8831 case elfcpp::R_ARM_LDR_SB_G2:
8832 case elfcpp::R_ARM_LDRS_SB_G0:
8833 case elfcpp::R_ARM_LDRS_SB_G1:
8834 case elfcpp::R_ARM_LDRS_SB_G2:
8835 case elfcpp::R_ARM_LDC_SB_G0:
8836 case elfcpp::R_ARM_LDC_SB_G1:
8837 case elfcpp::R_ARM_LDC_SB_G2:
8838 case elfcpp::R_ARM_MOVW_BREL_NC:
8839 case elfcpp::R_ARM_MOVT_BREL:
8840 case elfcpp::R_ARM_MOVW_BREL:
8841 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8842 case elfcpp::R_ARM_THM_MOVT_BREL:
8843 case elfcpp::R_ARM_THM_MOVW_BREL:
8844 // Relative addressing relocations.
8845 {
8846 // Make a dynamic relocation if necessary.
8847 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8848 {
8849 if (parameters->options().output_is_executable()
8850 && target->may_need_copy_reloc(gsym))
8851 {
8852 target->copy_reloc(symtab, layout, object,
8853 data_shndx, output_section, gsym, reloc);
8854 }
8855 else
8856 {
8857 check_non_pic(object, r_type);
8858 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8859 rel_dyn->add_global(gsym, r_type, output_section, object,
8860 data_shndx, reloc.get_r_offset());
8861 }
8862 }
8863 }
8864 break;
8865
8866 case elfcpp::R_ARM_THM_CALL:
8867 case elfcpp::R_ARM_PLT32:
8868 case elfcpp::R_ARM_CALL:
8869 case elfcpp::R_ARM_JUMP24:
8870 case elfcpp::R_ARM_THM_JUMP24:
8871 case elfcpp::R_ARM_SBREL31:
8872 case elfcpp::R_ARM_PREL31:
8873 case elfcpp::R_ARM_THM_JUMP19:
8874 case elfcpp::R_ARM_THM_JUMP6:
8875 case elfcpp::R_ARM_THM_JUMP11:
8876 case elfcpp::R_ARM_THM_JUMP8:
8877 // All the relocation above are branches except for the PREL31 ones.
8878 // A PREL31 relocation can point to a personality function in a shared
8879 // library. In that case we want to use a PLT because we want to
8880 // call the personality routine and the dynamic linkers we care about
8881 // do not support dynamic PREL31 relocations. An REL31 relocation may
8882 // point to a function whose unwinding behaviour is being described but
8883 // we will not mistakenly generate a PLT for that because we should use
8884 // a local section symbol.
8885
8886 // If the symbol is fully resolved, this is just a relative
8887 // local reloc. Otherwise we need a PLT entry.
8888 if (gsym->final_value_is_known())
8889 break;
8890 // If building a shared library, we can also skip the PLT entry
8891 // if the symbol is defined in the output file and is protected
8892 // or hidden.
8893 if (gsym->is_defined()
8894 && !gsym->is_from_dynobj()
8895 && !gsym->is_preemptible())
8896 break;
8897 target->make_plt_entry(symtab, layout, gsym);
8898 break;
8899
8900 case elfcpp::R_ARM_GOT_BREL:
8901 case elfcpp::R_ARM_GOT_ABS:
8902 case elfcpp::R_ARM_GOT_PREL:
8903 {
8904 // The symbol requires a GOT entry.
8905 Arm_output_data_got<big_endian>* got =
8906 target->got_section(symtab, layout);
8907 if (gsym->final_value_is_known())
8908 {
8909 // For a STT_GNU_IFUNC symbol we want the PLT address.
8910 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
8911 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8912 else
8913 got->add_global(gsym, GOT_TYPE_STANDARD);
8914 }
8915 else
8916 {
8917 // If this symbol is not fully resolved, we need to add a
8918 // GOT entry with a dynamic relocation.
8919 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8920 if (gsym->is_from_dynobj()
8921 || gsym->is_undefined()
8922 || gsym->is_preemptible()
8923 || (gsym->visibility() == elfcpp::STV_PROTECTED
8924 && parameters->options().shared())
8925 || (gsym->type() == elfcpp::STT_GNU_IFUNC
8926 && parameters->options().output_is_position_independent()))
8927 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8928 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8929 else
8930 {
8931 // For a STT_GNU_IFUNC symbol we want to write the PLT
8932 // offset into the GOT, so that function pointer
8933 // comparisons work correctly.
8934 bool is_new;
8935 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
8936 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
8937 else
8938 {
8939 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8940 // Tell the dynamic linker to use the PLT address
8941 // when resolving relocations.
8942 if (gsym->is_from_dynobj()
8943 && !parameters->options().shared())
8944 gsym->set_needs_dynsym_value();
8945 }
8946 if (is_new)
8947 rel_dyn->add_global_relative(
8948 gsym, elfcpp::R_ARM_RELATIVE, got,
8949 gsym->got_offset(GOT_TYPE_STANDARD));
8950 }
8951 }
8952 }
8953 break;
8954
8955 case elfcpp::R_ARM_TARGET1:
8956 case elfcpp::R_ARM_TARGET2:
8957 // These should have been mapped to other types already.
8958 // Fall through.
8959 case elfcpp::R_ARM_COPY:
8960 case elfcpp::R_ARM_GLOB_DAT:
8961 case elfcpp::R_ARM_JUMP_SLOT:
8962 case elfcpp::R_ARM_RELATIVE:
8963 // These are relocations which should only be seen by the
8964 // dynamic linker, and should never be seen here.
8965 gold_error(_("%s: unexpected reloc %u in object file"),
8966 object->name().c_str(), r_type);
8967 break;
8968
8969 // These are initial tls relocs, which are expected when
8970 // linking.
8971 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8972 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8973 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8974 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8975 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8976 {
8977 const bool is_final = gsym->final_value_is_known();
8978 const tls::Tls_optimization optimized_type
8979 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8980 switch (r_type)
8981 {
8982 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8983 if (optimized_type == tls::TLSOPT_NONE)
8984 {
8985 // Create a pair of GOT entries for the module index and
8986 // dtv-relative offset.
8987 Arm_output_data_got<big_endian>* got
8988 = target->got_section(symtab, layout);
8989 if (!parameters->doing_static_link())
8990 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8991 target->rel_dyn_section(layout),
8992 elfcpp::R_ARM_TLS_DTPMOD32,
8993 elfcpp::R_ARM_TLS_DTPOFF32);
8994 else
8995 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8996 }
8997 else
8998 // FIXME: TLS optimization not supported yet.
8999 gold_unreachable();
9000 break;
9001
9002 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9003 if (optimized_type == tls::TLSOPT_NONE)
9004 {
9005 // Create a GOT entry for the module index.
9006 target->got_mod_index_entry(symtab, layout, object);
9007 }
9008 else
9009 // FIXME: TLS optimization not supported yet.
9010 gold_unreachable();
9011 break;
9012
9013 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9014 break;
9015
9016 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9017 layout->set_has_static_tls();
9018 if (optimized_type == tls::TLSOPT_NONE)
9019 {
9020 // Create a GOT entry for the tp-relative offset.
9021 Arm_output_data_got<big_endian>* got
9022 = target->got_section(symtab, layout);
9023 if (!parameters->doing_static_link())
9024 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
9025 target->rel_dyn_section(layout),
9026 elfcpp::R_ARM_TLS_TPOFF32);
9027 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
9028 {
9029 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
9030 unsigned int got_offset =
9031 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
9032 got->add_static_reloc(got_offset,
9033 elfcpp::R_ARM_TLS_TPOFF32, gsym);
9034 }
9035 }
9036 else
9037 // FIXME: TLS optimization not supported yet.
9038 gold_unreachable();
9039 break;
9040
9041 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9042 layout->set_has_static_tls();
9043 if (parameters->options().shared())
9044 {
9045 // We need to create a dynamic relocation.
9046 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9047 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
9048 output_section, object,
9049 data_shndx, reloc.get_r_offset());
9050 }
9051 break;
9052
9053 default:
9054 gold_unreachable();
9055 }
9056 }
9057 break;
9058
9059 case elfcpp::R_ARM_PC24:
9060 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9061 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9062 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9063 default:
9064 unsupported_reloc_global(object, r_type, gsym);
9065 break;
9066 }
9067 }
9068
9069 // Process relocations for gc.
9070
9071 template<bool big_endian>
9072 void
9073 Target_arm<big_endian>::gc_process_relocs(
9074 Symbol_table* symtab,
9075 Layout* layout,
9076 Sized_relobj_file<32, big_endian>* object,
9077 unsigned int data_shndx,
9078 unsigned int,
9079 const unsigned char* prelocs,
9080 size_t reloc_count,
9081 Output_section* output_section,
9082 bool needs_special_offset_handling,
9083 size_t local_symbol_count,
9084 const unsigned char* plocal_symbols)
9085 {
9086 typedef Target_arm<big_endian> Arm;
9087 typedef typename Target_arm<big_endian>::Scan Scan;
9088
9089 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
9090 typename Target_arm::Relocatable_size_for_reloc>(
9091 symtab,
9092 layout,
9093 this,
9094 object,
9095 data_shndx,
9096 prelocs,
9097 reloc_count,
9098 output_section,
9099 needs_special_offset_handling,
9100 local_symbol_count,
9101 plocal_symbols);
9102 }
9103
9104 // Scan relocations for a section.
9105
9106 template<bool big_endian>
9107 void
9108 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
9109 Layout* layout,
9110 Sized_relobj_file<32, big_endian>* object,
9111 unsigned int data_shndx,
9112 unsigned int sh_type,
9113 const unsigned char* prelocs,
9114 size_t reloc_count,
9115 Output_section* output_section,
9116 bool needs_special_offset_handling,
9117 size_t local_symbol_count,
9118 const unsigned char* plocal_symbols)
9119 {
9120 typedef typename Target_arm<big_endian>::Scan Scan;
9121 if (sh_type == elfcpp::SHT_RELA)
9122 {
9123 gold_error(_("%s: unsupported RELA reloc section"),
9124 object->name().c_str());
9125 return;
9126 }
9127
9128 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
9129 symtab,
9130 layout,
9131 this,
9132 object,
9133 data_shndx,
9134 prelocs,
9135 reloc_count,
9136 output_section,
9137 needs_special_offset_handling,
9138 local_symbol_count,
9139 plocal_symbols);
9140 }
9141
9142 // Finalize the sections.
9143
9144 template<bool big_endian>
9145 void
9146 Target_arm<big_endian>::do_finalize_sections(
9147 Layout* layout,
9148 const Input_objects* input_objects,
9149 Symbol_table*)
9150 {
9151 bool merged_any_attributes = false;
9152 // Merge processor-specific flags.
9153 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
9154 p != input_objects->relobj_end();
9155 ++p)
9156 {
9157 Arm_relobj<big_endian>* arm_relobj =
9158 Arm_relobj<big_endian>::as_arm_relobj(*p);
9159 if (arm_relobj->merge_flags_and_attributes())
9160 {
9161 this->merge_processor_specific_flags(
9162 arm_relobj->name(),
9163 arm_relobj->processor_specific_flags());
9164 this->merge_object_attributes(arm_relobj->name().c_str(),
9165 arm_relobj->attributes_section_data());
9166 merged_any_attributes = true;
9167 }
9168 }
9169
9170 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
9171 p != input_objects->dynobj_end();
9172 ++p)
9173 {
9174 Arm_dynobj<big_endian>* arm_dynobj =
9175 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
9176 this->merge_processor_specific_flags(
9177 arm_dynobj->name(),
9178 arm_dynobj->processor_specific_flags());
9179 this->merge_object_attributes(arm_dynobj->name().c_str(),
9180 arm_dynobj->attributes_section_data());
9181 merged_any_attributes = true;
9182 }
9183
9184 // Create an empty uninitialized attribute section if we still don't have it
9185 // at this moment. This happens if there is no attributes sections in all
9186 // inputs.
9187 if (this->attributes_section_data_ == NULL)
9188 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
9189
9190 const Object_attribute* cpu_arch_attr =
9191 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
9192 // Check if we need to use Cortex-A8 workaround.
9193 if (parameters->options().user_set_fix_cortex_a8())
9194 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
9195 else
9196 {
9197 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
9198 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
9199 // profile.
9200 const Object_attribute* cpu_arch_profile_attr =
9201 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
9202 this->fix_cortex_a8_ =
9203 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
9204 && (cpu_arch_profile_attr->int_value() == 'A'
9205 || cpu_arch_profile_attr->int_value() == 0));
9206 }
9207
9208 // Check if we can use V4BX interworking.
9209 // The V4BX interworking stub contains BX instruction,
9210 // which is not specified for some profiles.
9211 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
9212 && !this->may_use_v4t_interworking())
9213 gold_error(_("unable to provide V4BX reloc interworking fix up; "
9214 "the target profile does not support BX instruction"));
9215
9216 // Fill in some more dynamic tags.
9217 const Reloc_section* rel_plt = (this->plt_ == NULL
9218 ? NULL
9219 : this->plt_->rel_plt());
9220 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
9221 this->rel_dyn_, true, false);
9222
9223 // Emit any relocs we saved in an attempt to avoid generating COPY
9224 // relocs.
9225 if (this->copy_relocs_.any_saved_relocs())
9226 this->copy_relocs_.emit(this->rel_dyn_section(layout));
9227
9228 // Handle the .ARM.exidx section.
9229 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
9230
9231 if (!parameters->options().relocatable())
9232 {
9233 if (exidx_section != NULL
9234 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
9235 {
9236 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
9237 // the .ARM.exidx section.
9238 if (!layout->script_options()->saw_phdrs_clause())
9239 {
9240 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
9241 0)
9242 == NULL);
9243 Output_segment* exidx_segment =
9244 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
9245 exidx_segment->add_output_section_to_nonload(exidx_section,
9246 elfcpp::PF_R);
9247 }
9248 }
9249 }
9250
9251 // Create an .ARM.attributes section if we have merged any attributes
9252 // from inputs.
9253 if (merged_any_attributes)
9254 {
9255 Output_attributes_section_data* attributes_section =
9256 new Output_attributes_section_data(*this->attributes_section_data_);
9257 layout->add_output_section_data(".ARM.attributes",
9258 elfcpp::SHT_ARM_ATTRIBUTES, 0,
9259 attributes_section, ORDER_INVALID,
9260 false);
9261 }
9262
9263 // Fix up links in section EXIDX headers.
9264 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
9265 p != layout->section_list().end();
9266 ++p)
9267 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
9268 {
9269 Arm_output_section<big_endian>* os =
9270 Arm_output_section<big_endian>::as_arm_output_section(*p);
9271 os->set_exidx_section_link();
9272 }
9273 }
9274
9275 // Return whether a direct absolute static relocation needs to be applied.
9276 // In cases where Scan::local() or Scan::global() has created
9277 // a dynamic relocation other than R_ARM_RELATIVE, the addend
9278 // of the relocation is carried in the data, and we must not
9279 // apply the static relocation.
9280
9281 template<bool big_endian>
9282 inline bool
9283 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
9284 const Sized_symbol<32>* gsym,
9285 unsigned int r_type,
9286 bool is_32bit,
9287 Output_section* output_section)
9288 {
9289 // If the output section is not allocated, then we didn't call
9290 // scan_relocs, we didn't create a dynamic reloc, and we must apply
9291 // the reloc here.
9292 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
9293 return true;
9294
9295 int ref_flags = Scan::get_reference_flags(r_type);
9296
9297 // For local symbols, we will have created a non-RELATIVE dynamic
9298 // relocation only if (a) the output is position independent,
9299 // (b) the relocation is absolute (not pc- or segment-relative), and
9300 // (c) the relocation is not 32 bits wide.
9301 if (gsym == NULL)
9302 return !(parameters->options().output_is_position_independent()
9303 && (ref_flags & Symbol::ABSOLUTE_REF)
9304 && !is_32bit);
9305
9306 // For global symbols, we use the same helper routines used in the
9307 // scan pass. If we did not create a dynamic relocation, or if we
9308 // created a RELATIVE dynamic relocation, we should apply the static
9309 // relocation.
9310 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
9311 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
9312 && gsym->can_use_relative_reloc(ref_flags
9313 & Symbol::FUNCTION_CALL);
9314 return !has_dyn || is_rel;
9315 }
9316
9317 // Perform a relocation.
9318
9319 template<bool big_endian>
9320 inline bool
9321 Target_arm<big_endian>::Relocate::relocate(
9322 const Relocate_info<32, big_endian>* relinfo,
9323 Target_arm* target,
9324 Output_section* output_section,
9325 size_t relnum,
9326 const elfcpp::Rel<32, big_endian>& rel,
9327 unsigned int r_type,
9328 const Sized_symbol<32>* gsym,
9329 const Symbol_value<32>* psymval,
9330 unsigned char* view,
9331 Arm_address address,
9332 section_size_type view_size)
9333 {
9334 if (view == NULL)
9335 return true;
9336
9337 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
9338
9339 r_type = get_real_reloc_type(r_type);
9340 const Arm_reloc_property* reloc_property =
9341 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9342 if (reloc_property == NULL)
9343 {
9344 std::string reloc_name =
9345 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9346 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9347 _("cannot relocate %s in object file"),
9348 reloc_name.c_str());
9349 return true;
9350 }
9351
9352 const Arm_relobj<big_endian>* object =
9353 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9354
9355 // If the final branch target of a relocation is THUMB instruction, this
9356 // is 1. Otherwise it is 0.
9357 Arm_address thumb_bit = 0;
9358 Symbol_value<32> symval;
9359 bool is_weakly_undefined_without_plt = false;
9360 bool have_got_offset = false;
9361 unsigned int got_offset = 0;
9362
9363 // If the relocation uses the GOT entry of a symbol instead of the symbol
9364 // itself, we don't care about whether the symbol is defined or what kind
9365 // of symbol it is.
9366 if (reloc_property->uses_got_entry())
9367 {
9368 // Get the GOT offset.
9369 // The GOT pointer points to the end of the GOT section.
9370 // We need to subtract the size of the GOT section to get
9371 // the actual offset to use in the relocation.
9372 // TODO: We should move GOT offset computing code in TLS relocations
9373 // to here.
9374 switch (r_type)
9375 {
9376 case elfcpp::R_ARM_GOT_BREL:
9377 case elfcpp::R_ARM_GOT_PREL:
9378 if (gsym != NULL)
9379 {
9380 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
9381 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
9382 - target->got_size());
9383 }
9384 else
9385 {
9386 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9387 gold_assert(object->local_has_got_offset(r_sym,
9388 GOT_TYPE_STANDARD));
9389 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
9390 - target->got_size());
9391 }
9392 have_got_offset = true;
9393 break;
9394
9395 default:
9396 break;
9397 }
9398 }
9399 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
9400 {
9401 if (gsym != NULL)
9402 {
9403 // This is a global symbol. Determine if we use PLT and if the
9404 // final target is THUMB.
9405 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
9406 {
9407 // This uses a PLT, change the symbol value.
9408 symval.set_output_value(target->plt_address_for_global(gsym));
9409 psymval = &symval;
9410 }
9411 else if (gsym->is_weak_undefined())
9412 {
9413 // This is a weakly undefined symbol and we do not use PLT
9414 // for this relocation. A branch targeting this symbol will
9415 // be converted into an NOP.
9416 is_weakly_undefined_without_plt = true;
9417 }
9418 else if (gsym->is_undefined() && reloc_property->uses_symbol())
9419 {
9420 // This relocation uses the symbol value but the symbol is
9421 // undefined. Exit early and have the caller reporting an
9422 // error.
9423 return true;
9424 }
9425 else
9426 {
9427 // Set thumb bit if symbol:
9428 // -Has type STT_ARM_TFUNC or
9429 // -Has type STT_FUNC, is defined and with LSB in value set.
9430 thumb_bit =
9431 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
9432 || (gsym->type() == elfcpp::STT_FUNC
9433 && !gsym->is_undefined()
9434 && ((psymval->value(object, 0) & 1) != 0)))
9435 ? 1
9436 : 0);
9437 }
9438 }
9439 else
9440 {
9441 // This is a local symbol. Determine if the final target is THUMB.
9442 // We saved this information when all the local symbols were read.
9443 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
9444 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9445 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9446
9447 if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
9448 {
9449 symval.set_output_value(
9450 target->plt_address_for_local(object, r_sym));
9451 psymval = &symval;
9452 }
9453 }
9454 }
9455 else
9456 {
9457 // This is a fake relocation synthesized for a stub. It does not have
9458 // a real symbol. We just look at the LSB of the symbol value to
9459 // determine if the target is THUMB or not.
9460 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
9461 }
9462
9463 // Strip LSB if this points to a THUMB target.
9464 if (thumb_bit != 0
9465 && reloc_property->uses_thumb_bit()
9466 && ((psymval->value(object, 0) & 1) != 0))
9467 {
9468 Arm_address stripped_value =
9469 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9470 symval.set_output_value(stripped_value);
9471 psymval = &symval;
9472 }
9473
9474 // To look up relocation stubs, we need to pass the symbol table index of
9475 // a local symbol.
9476 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9477
9478 // Get the addressing origin of the output segment defining the
9479 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
9480 Arm_address sym_origin = 0;
9481 if (reloc_property->uses_symbol_base())
9482 {
9483 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
9484 // R_ARM_BASE_ABS with the NULL symbol will give the
9485 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
9486 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
9487 sym_origin = target->got_plt_section()->address();
9488 else if (gsym == NULL)
9489 sym_origin = 0;
9490 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
9491 sym_origin = gsym->output_segment()->vaddr();
9492 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9493 sym_origin = gsym->output_data()->address();
9494
9495 // TODO: Assumes the segment base to be zero for the global symbols
9496 // till the proper support for the segment-base-relative addressing
9497 // will be implemented. This is consistent with GNU ld.
9498 }
9499
9500 // For relative addressing relocation, find out the relative address base.
9501 Arm_address relative_address_base = 0;
9502 switch(reloc_property->relative_address_base())
9503 {
9504 case Arm_reloc_property::RAB_NONE:
9505 // Relocations with relative address bases RAB_TLS and RAB_tp are
9506 // handled by relocate_tls. So we do not need to do anything here.
9507 case Arm_reloc_property::RAB_TLS:
9508 case Arm_reloc_property::RAB_tp:
9509 break;
9510 case Arm_reloc_property::RAB_B_S:
9511 relative_address_base = sym_origin;
9512 break;
9513 case Arm_reloc_property::RAB_GOT_ORG:
9514 relative_address_base = target->got_plt_section()->address();
9515 break;
9516 case Arm_reloc_property::RAB_P:
9517 relative_address_base = address;
9518 break;
9519 case Arm_reloc_property::RAB_Pa:
9520 relative_address_base = address & 0xfffffffcU;
9521 break;
9522 default:
9523 gold_unreachable();
9524 }
9525
9526 typename Arm_relocate_functions::Status reloc_status =
9527 Arm_relocate_functions::STATUS_OKAY;
9528 bool check_overflow = reloc_property->checks_overflow();
9529 switch (r_type)
9530 {
9531 case elfcpp::R_ARM_NONE:
9532 break;
9533
9534 case elfcpp::R_ARM_ABS8:
9535 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9536 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9537 break;
9538
9539 case elfcpp::R_ARM_ABS12:
9540 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9541 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9542 break;
9543
9544 case elfcpp::R_ARM_ABS16:
9545 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9546 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9547 break;
9548
9549 case elfcpp::R_ARM_ABS32:
9550 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9551 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9552 thumb_bit);
9553 break;
9554
9555 case elfcpp::R_ARM_ABS32_NOI:
9556 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9557 // No thumb bit for this relocation: (S + A)
9558 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9559 0);
9560 break;
9561
9562 case elfcpp::R_ARM_MOVW_ABS_NC:
9563 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9564 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9565 0, thumb_bit,
9566 check_overflow);
9567 break;
9568
9569 case elfcpp::R_ARM_MOVT_ABS:
9570 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9571 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9572 break;
9573
9574 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9575 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9576 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9577 0, thumb_bit, false);
9578 break;
9579
9580 case elfcpp::R_ARM_THM_MOVT_ABS:
9581 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9582 reloc_status = Arm_relocate_functions::thm_movt(view, object,
9583 psymval, 0);
9584 break;
9585
9586 case elfcpp::R_ARM_MOVW_PREL_NC:
9587 case elfcpp::R_ARM_MOVW_BREL_NC:
9588 case elfcpp::R_ARM_MOVW_BREL:
9589 reloc_status =
9590 Arm_relocate_functions::movw(view, object, psymval,
9591 relative_address_base, thumb_bit,
9592 check_overflow);
9593 break;
9594
9595 case elfcpp::R_ARM_MOVT_PREL:
9596 case elfcpp::R_ARM_MOVT_BREL:
9597 reloc_status =
9598 Arm_relocate_functions::movt(view, object, psymval,
9599 relative_address_base);
9600 break;
9601
9602 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9603 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9604 case elfcpp::R_ARM_THM_MOVW_BREL:
9605 reloc_status =
9606 Arm_relocate_functions::thm_movw(view, object, psymval,
9607 relative_address_base,
9608 thumb_bit, check_overflow);
9609 break;
9610
9611 case elfcpp::R_ARM_THM_MOVT_PREL:
9612 case elfcpp::R_ARM_THM_MOVT_BREL:
9613 reloc_status =
9614 Arm_relocate_functions::thm_movt(view, object, psymval,
9615 relative_address_base);
9616 break;
9617
9618 case elfcpp::R_ARM_REL32:
9619 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9620 address, thumb_bit);
9621 break;
9622
9623 case elfcpp::R_ARM_THM_ABS5:
9624 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9625 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9626 break;
9627
9628 // Thumb long branches.
9629 case elfcpp::R_ARM_THM_CALL:
9630 case elfcpp::R_ARM_THM_XPC22:
9631 case elfcpp::R_ARM_THM_JUMP24:
9632 reloc_status =
9633 Arm_relocate_functions::thumb_branch_common(
9634 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9635 thumb_bit, is_weakly_undefined_without_plt);
9636 break;
9637
9638 case elfcpp::R_ARM_GOTOFF32:
9639 {
9640 Arm_address got_origin;
9641 got_origin = target->got_plt_section()->address();
9642 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9643 got_origin, thumb_bit);
9644 }
9645 break;
9646
9647 case elfcpp::R_ARM_BASE_PREL:
9648 gold_assert(gsym != NULL);
9649 reloc_status =
9650 Arm_relocate_functions::base_prel(view, sym_origin, address);
9651 break;
9652
9653 case elfcpp::R_ARM_BASE_ABS:
9654 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9655 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9656 break;
9657
9658 case elfcpp::R_ARM_GOT_BREL:
9659 gold_assert(have_got_offset);
9660 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9661 break;
9662
9663 case elfcpp::R_ARM_GOT_PREL:
9664 gold_assert(have_got_offset);
9665 // Get the address origin for GOT PLT, which is allocated right
9666 // after the GOT section, to calculate an absolute address of
9667 // the symbol GOT entry (got_origin + got_offset).
9668 Arm_address got_origin;
9669 got_origin = target->got_plt_section()->address();
9670 reloc_status = Arm_relocate_functions::got_prel(view,
9671 got_origin + got_offset,
9672 address);
9673 break;
9674
9675 case elfcpp::R_ARM_PLT32:
9676 case elfcpp::R_ARM_CALL:
9677 case elfcpp::R_ARM_JUMP24:
9678 case elfcpp::R_ARM_XPC25:
9679 gold_assert(gsym == NULL
9680 || gsym->has_plt_offset()
9681 || gsym->final_value_is_known()
9682 || (gsym->is_defined()
9683 && !gsym->is_from_dynobj()
9684 && !gsym->is_preemptible()));
9685 reloc_status =
9686 Arm_relocate_functions::arm_branch_common(
9687 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9688 thumb_bit, is_weakly_undefined_without_plt);
9689 break;
9690
9691 case elfcpp::R_ARM_THM_JUMP19:
9692 reloc_status =
9693 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9694 thumb_bit);
9695 break;
9696
9697 case elfcpp::R_ARM_THM_JUMP6:
9698 reloc_status =
9699 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9700 break;
9701
9702 case elfcpp::R_ARM_THM_JUMP8:
9703 reloc_status =
9704 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9705 break;
9706
9707 case elfcpp::R_ARM_THM_JUMP11:
9708 reloc_status =
9709 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9710 break;
9711
9712 case elfcpp::R_ARM_PREL31:
9713 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9714 address, thumb_bit);
9715 break;
9716
9717 case elfcpp::R_ARM_V4BX:
9718 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9719 {
9720 const bool is_v4bx_interworking =
9721 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9722 reloc_status =
9723 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9724 is_v4bx_interworking);
9725 }
9726 break;
9727
9728 case elfcpp::R_ARM_THM_PC8:
9729 reloc_status =
9730 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9731 break;
9732
9733 case elfcpp::R_ARM_THM_PC12:
9734 reloc_status =
9735 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9736 break;
9737
9738 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9739 reloc_status =
9740 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9741 thumb_bit);
9742 break;
9743
9744 case elfcpp::R_ARM_ALU_PC_G0_NC:
9745 case elfcpp::R_ARM_ALU_PC_G0:
9746 case elfcpp::R_ARM_ALU_PC_G1_NC:
9747 case elfcpp::R_ARM_ALU_PC_G1:
9748 case elfcpp::R_ARM_ALU_PC_G2:
9749 case elfcpp::R_ARM_ALU_SB_G0_NC:
9750 case elfcpp::R_ARM_ALU_SB_G0:
9751 case elfcpp::R_ARM_ALU_SB_G1_NC:
9752 case elfcpp::R_ARM_ALU_SB_G1:
9753 case elfcpp::R_ARM_ALU_SB_G2:
9754 reloc_status =
9755 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9756 reloc_property->group_index(),
9757 relative_address_base,
9758 thumb_bit, check_overflow);
9759 break;
9760
9761 case elfcpp::R_ARM_LDR_PC_G0:
9762 case elfcpp::R_ARM_LDR_PC_G1:
9763 case elfcpp::R_ARM_LDR_PC_G2:
9764 case elfcpp::R_ARM_LDR_SB_G0:
9765 case elfcpp::R_ARM_LDR_SB_G1:
9766 case elfcpp::R_ARM_LDR_SB_G2:
9767 reloc_status =
9768 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9769 reloc_property->group_index(),
9770 relative_address_base);
9771 break;
9772
9773 case elfcpp::R_ARM_LDRS_PC_G0:
9774 case elfcpp::R_ARM_LDRS_PC_G1:
9775 case elfcpp::R_ARM_LDRS_PC_G2:
9776 case elfcpp::R_ARM_LDRS_SB_G0:
9777 case elfcpp::R_ARM_LDRS_SB_G1:
9778 case elfcpp::R_ARM_LDRS_SB_G2:
9779 reloc_status =
9780 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9781 reloc_property->group_index(),
9782 relative_address_base);
9783 break;
9784
9785 case elfcpp::R_ARM_LDC_PC_G0:
9786 case elfcpp::R_ARM_LDC_PC_G1:
9787 case elfcpp::R_ARM_LDC_PC_G2:
9788 case elfcpp::R_ARM_LDC_SB_G0:
9789 case elfcpp::R_ARM_LDC_SB_G1:
9790 case elfcpp::R_ARM_LDC_SB_G2:
9791 reloc_status =
9792 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9793 reloc_property->group_index(),
9794 relative_address_base);
9795 break;
9796
9797 // These are initial tls relocs, which are expected when
9798 // linking.
9799 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9800 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9801 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9802 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9803 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9804 reloc_status =
9805 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9806 view, address, view_size);
9807 break;
9808
9809 // The known and unknown unsupported and/or deprecated relocations.
9810 case elfcpp::R_ARM_PC24:
9811 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9812 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9813 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9814 default:
9815 // Just silently leave the method. We should get an appropriate error
9816 // message in the scan methods.
9817 break;
9818 }
9819
9820 // Report any errors.
9821 switch (reloc_status)
9822 {
9823 case Arm_relocate_functions::STATUS_OKAY:
9824 break;
9825 case Arm_relocate_functions::STATUS_OVERFLOW:
9826 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9827 _("relocation overflow in %s"),
9828 reloc_property->name().c_str());
9829 break;
9830 case Arm_relocate_functions::STATUS_BAD_RELOC:
9831 gold_error_at_location(
9832 relinfo,
9833 relnum,
9834 rel.get_r_offset(),
9835 _("unexpected opcode while processing relocation %s"),
9836 reloc_property->name().c_str());
9837 break;
9838 default:
9839 gold_unreachable();
9840 }
9841
9842 return true;
9843 }
9844
9845 // Perform a TLS relocation.
9846
9847 template<bool big_endian>
9848 inline typename Arm_relocate_functions<big_endian>::Status
9849 Target_arm<big_endian>::Relocate::relocate_tls(
9850 const Relocate_info<32, big_endian>* relinfo,
9851 Target_arm<big_endian>* target,
9852 size_t relnum,
9853 const elfcpp::Rel<32, big_endian>& rel,
9854 unsigned int r_type,
9855 const Sized_symbol<32>* gsym,
9856 const Symbol_value<32>* psymval,
9857 unsigned char* view,
9858 elfcpp::Elf_types<32>::Elf_Addr address,
9859 section_size_type /*view_size*/ )
9860 {
9861 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9862 typedef Relocate_functions<32, big_endian> RelocFuncs;
9863 Output_segment* tls_segment = relinfo->layout->tls_segment();
9864
9865 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9866
9867 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9868
9869 const bool is_final = (gsym == NULL
9870 ? !parameters->options().shared()
9871 : gsym->final_value_is_known());
9872 const tls::Tls_optimization optimized_type
9873 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9874 switch (r_type)
9875 {
9876 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9877 {
9878 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9879 unsigned int got_offset;
9880 if (gsym != NULL)
9881 {
9882 gold_assert(gsym->has_got_offset(got_type));
9883 got_offset = gsym->got_offset(got_type) - target->got_size();
9884 }
9885 else
9886 {
9887 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9888 gold_assert(object->local_has_got_offset(r_sym, got_type));
9889 got_offset = (object->local_got_offset(r_sym, got_type)
9890 - target->got_size());
9891 }
9892 if (optimized_type == tls::TLSOPT_NONE)
9893 {
9894 Arm_address got_entry =
9895 target->got_plt_section()->address() + got_offset;
9896
9897 // Relocate the field with the PC relative offset of the pair of
9898 // GOT entries.
9899 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9900 return ArmRelocFuncs::STATUS_OKAY;
9901 }
9902 }
9903 break;
9904
9905 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9906 if (optimized_type == tls::TLSOPT_NONE)
9907 {
9908 // Relocate the field with the offset of the GOT entry for
9909 // the module index.
9910 unsigned int got_offset;
9911 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9912 - target->got_size());
9913 Arm_address got_entry =
9914 target->got_plt_section()->address() + got_offset;
9915
9916 // Relocate the field with the PC relative offset of the pair of
9917 // GOT entries.
9918 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9919 return ArmRelocFuncs::STATUS_OKAY;
9920 }
9921 break;
9922
9923 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9924 RelocFuncs::rel32_unaligned(view, value);
9925 return ArmRelocFuncs::STATUS_OKAY;
9926
9927 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9928 if (optimized_type == tls::TLSOPT_NONE)
9929 {
9930 // Relocate the field with the offset of the GOT entry for
9931 // the tp-relative offset of the symbol.
9932 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9933 unsigned int got_offset;
9934 if (gsym != NULL)
9935 {
9936 gold_assert(gsym->has_got_offset(got_type));
9937 got_offset = gsym->got_offset(got_type);
9938 }
9939 else
9940 {
9941 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9942 gold_assert(object->local_has_got_offset(r_sym, got_type));
9943 got_offset = object->local_got_offset(r_sym, got_type);
9944 }
9945
9946 // All GOT offsets are relative to the end of the GOT.
9947 got_offset -= target->got_size();
9948
9949 Arm_address got_entry =
9950 target->got_plt_section()->address() + got_offset;
9951
9952 // Relocate the field with the PC relative offset of the GOT entry.
9953 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9954 return ArmRelocFuncs::STATUS_OKAY;
9955 }
9956 break;
9957
9958 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9959 // If we're creating a shared library, a dynamic relocation will
9960 // have been created for this location, so do not apply it now.
9961 if (!parameters->options().shared())
9962 {
9963 gold_assert(tls_segment != NULL);
9964
9965 // $tp points to the TCB, which is followed by the TLS, so we
9966 // need to add TCB size to the offset.
9967 Arm_address aligned_tcb_size =
9968 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9969 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9970
9971 }
9972 return ArmRelocFuncs::STATUS_OKAY;
9973
9974 default:
9975 gold_unreachable();
9976 }
9977
9978 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9979 _("unsupported reloc %u"),
9980 r_type);
9981 return ArmRelocFuncs::STATUS_BAD_RELOC;
9982 }
9983
9984 // Relocate section data.
9985
9986 template<bool big_endian>
9987 void
9988 Target_arm<big_endian>::relocate_section(
9989 const Relocate_info<32, big_endian>* relinfo,
9990 unsigned int sh_type,
9991 const unsigned char* prelocs,
9992 size_t reloc_count,
9993 Output_section* output_section,
9994 bool needs_special_offset_handling,
9995 unsigned char* view,
9996 Arm_address address,
9997 section_size_type view_size,
9998 const Reloc_symbol_changes* reloc_symbol_changes)
9999 {
10000 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
10001 gold_assert(sh_type == elfcpp::SHT_REL);
10002
10003 // See if we are relocating a relaxed input section. If so, the view
10004 // covers the whole output section and we need to adjust accordingly.
10005 if (needs_special_offset_handling)
10006 {
10007 const Output_relaxed_input_section* poris =
10008 output_section->find_relaxed_input_section(relinfo->object,
10009 relinfo->data_shndx);
10010 if (poris != NULL)
10011 {
10012 Arm_address section_address = poris->address();
10013 section_size_type section_size = poris->data_size();
10014
10015 gold_assert((section_address >= address)
10016 && ((section_address + section_size)
10017 <= (address + view_size)));
10018
10019 off_t offset = section_address - address;
10020 view += offset;
10021 address += offset;
10022 view_size = section_size;
10023 }
10024 }
10025
10026 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
10027 Arm_relocate, gold::Default_comdat_behavior>(
10028 relinfo,
10029 this,
10030 prelocs,
10031 reloc_count,
10032 output_section,
10033 needs_special_offset_handling,
10034 view,
10035 address,
10036 view_size,
10037 reloc_symbol_changes);
10038 }
10039
10040 // Return the size of a relocation while scanning during a relocatable
10041 // link.
10042
10043 template<bool big_endian>
10044 unsigned int
10045 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
10046 unsigned int r_type,
10047 Relobj* object)
10048 {
10049 r_type = get_real_reloc_type(r_type);
10050 const Arm_reloc_property* arp =
10051 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10052 if (arp != NULL)
10053 return arp->size();
10054 else
10055 {
10056 std::string reloc_name =
10057 arm_reloc_property_table->reloc_name_in_error_message(r_type);
10058 gold_error(_("%s: unexpected %s in object file"),
10059 object->name().c_str(), reloc_name.c_str());
10060 return 0;
10061 }
10062 }
10063
10064 // Scan the relocs during a relocatable link.
10065
10066 template<bool big_endian>
10067 void
10068 Target_arm<big_endian>::scan_relocatable_relocs(
10069 Symbol_table* symtab,
10070 Layout* layout,
10071 Sized_relobj_file<32, big_endian>* object,
10072 unsigned int data_shndx,
10073 unsigned int sh_type,
10074 const unsigned char* prelocs,
10075 size_t reloc_count,
10076 Output_section* output_section,
10077 bool needs_special_offset_handling,
10078 size_t local_symbol_count,
10079 const unsigned char* plocal_symbols,
10080 Relocatable_relocs* rr)
10081 {
10082 gold_assert(sh_type == elfcpp::SHT_REL);
10083
10084 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
10085 Relocatable_size_for_reloc> Scan_relocatable_relocs;
10086
10087 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
10088 Scan_relocatable_relocs>(
10089 symtab,
10090 layout,
10091 object,
10092 data_shndx,
10093 prelocs,
10094 reloc_count,
10095 output_section,
10096 needs_special_offset_handling,
10097 local_symbol_count,
10098 plocal_symbols,
10099 rr);
10100 }
10101
10102 // Emit relocations for a section.
10103
10104 template<bool big_endian>
10105 void
10106 Target_arm<big_endian>::relocate_relocs(
10107 const Relocate_info<32, big_endian>* relinfo,
10108 unsigned int sh_type,
10109 const unsigned char* prelocs,
10110 size_t reloc_count,
10111 Output_section* output_section,
10112 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10113 const Relocatable_relocs* rr,
10114 unsigned char* view,
10115 Arm_address view_address,
10116 section_size_type view_size,
10117 unsigned char* reloc_view,
10118 section_size_type reloc_view_size)
10119 {
10120 gold_assert(sh_type == elfcpp::SHT_REL);
10121
10122 gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
10123 relinfo,
10124 prelocs,
10125 reloc_count,
10126 output_section,
10127 offset_in_output_section,
10128 rr,
10129 view,
10130 view_address,
10131 view_size,
10132 reloc_view,
10133 reloc_view_size);
10134 }
10135
10136 // Perform target-specific processing in a relocatable link. This is
10137 // only used if we use the relocation strategy RELOC_SPECIAL.
10138
10139 template<bool big_endian>
10140 void
10141 Target_arm<big_endian>::relocate_special_relocatable(
10142 const Relocate_info<32, big_endian>* relinfo,
10143 unsigned int sh_type,
10144 const unsigned char* preloc_in,
10145 size_t relnum,
10146 Output_section* output_section,
10147 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10148 unsigned char* view,
10149 elfcpp::Elf_types<32>::Elf_Addr view_address,
10150 section_size_type,
10151 unsigned char* preloc_out)
10152 {
10153 // We can only handle REL type relocation sections.
10154 gold_assert(sh_type == elfcpp::SHT_REL);
10155
10156 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
10157 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
10158 Reltype_write;
10159 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
10160
10161 const Arm_relobj<big_endian>* object =
10162 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10163 const unsigned int local_count = object->local_symbol_count();
10164
10165 Reltype reloc(preloc_in);
10166 Reltype_write reloc_write(preloc_out);
10167
10168 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10169 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10170 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10171
10172 const Arm_reloc_property* arp =
10173 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10174 gold_assert(arp != NULL);
10175
10176 // Get the new symbol index.
10177 // We only use RELOC_SPECIAL strategy in local relocations.
10178 gold_assert(r_sym < local_count);
10179
10180 // We are adjusting a section symbol. We need to find
10181 // the symbol table index of the section symbol for
10182 // the output section corresponding to input section
10183 // in which this symbol is defined.
10184 bool is_ordinary;
10185 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
10186 gold_assert(is_ordinary);
10187 Output_section* os = object->output_section(shndx);
10188 gold_assert(os != NULL);
10189 gold_assert(os->needs_symtab_index());
10190 unsigned int new_symndx = os->symtab_index();
10191
10192 // Get the new offset--the location in the output section where
10193 // this relocation should be applied.
10194
10195 Arm_address offset = reloc.get_r_offset();
10196 Arm_address new_offset;
10197 if (offset_in_output_section != invalid_address)
10198 new_offset = offset + offset_in_output_section;
10199 else
10200 {
10201 section_offset_type sot_offset =
10202 convert_types<section_offset_type, Arm_address>(offset);
10203 section_offset_type new_sot_offset =
10204 output_section->output_offset(object, relinfo->data_shndx,
10205 sot_offset);
10206 gold_assert(new_sot_offset != -1);
10207 new_offset = new_sot_offset;
10208 }
10209
10210 // In an object file, r_offset is an offset within the section.
10211 // In an executable or dynamic object, generated by
10212 // --emit-relocs, r_offset is an absolute address.
10213 if (!parameters->options().relocatable())
10214 {
10215 new_offset += view_address;
10216 if (offset_in_output_section != invalid_address)
10217 new_offset -= offset_in_output_section;
10218 }
10219
10220 reloc_write.put_r_offset(new_offset);
10221 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
10222
10223 // Handle the reloc addend.
10224 // The relocation uses a section symbol in the input file.
10225 // We are adjusting it to use a section symbol in the output
10226 // file. The input section symbol refers to some address in
10227 // the input section. We need the relocation in the output
10228 // file to refer to that same address. This adjustment to
10229 // the addend is the same calculation we use for a simple
10230 // absolute relocation for the input section symbol.
10231
10232 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
10233
10234 // Handle THUMB bit.
10235 Symbol_value<32> symval;
10236 Arm_address thumb_bit =
10237 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
10238 if (thumb_bit != 0
10239 && arp->uses_thumb_bit()
10240 && ((psymval->value(object, 0) & 1) != 0))
10241 {
10242 Arm_address stripped_value =
10243 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
10244 symval.set_output_value(stripped_value);
10245 psymval = &symval;
10246 }
10247
10248 unsigned char* paddend = view + offset;
10249 typename Arm_relocate_functions<big_endian>::Status reloc_status =
10250 Arm_relocate_functions<big_endian>::STATUS_OKAY;
10251 switch (r_type)
10252 {
10253 case elfcpp::R_ARM_ABS8:
10254 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
10255 psymval);
10256 break;
10257
10258 case elfcpp::R_ARM_ABS12:
10259 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
10260 psymval);
10261 break;
10262
10263 case elfcpp::R_ARM_ABS16:
10264 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
10265 psymval);
10266 break;
10267
10268 case elfcpp::R_ARM_THM_ABS5:
10269 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
10270 object,
10271 psymval);
10272 break;
10273
10274 case elfcpp::R_ARM_MOVW_ABS_NC:
10275 case elfcpp::R_ARM_MOVW_PREL_NC:
10276 case elfcpp::R_ARM_MOVW_BREL_NC:
10277 case elfcpp::R_ARM_MOVW_BREL:
10278 reloc_status = Arm_relocate_functions<big_endian>::movw(
10279 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10280 break;
10281
10282 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
10283 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
10284 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
10285 case elfcpp::R_ARM_THM_MOVW_BREL:
10286 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
10287 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10288 break;
10289
10290 case elfcpp::R_ARM_THM_CALL:
10291 case elfcpp::R_ARM_THM_XPC22:
10292 case elfcpp::R_ARM_THM_JUMP24:
10293 reloc_status =
10294 Arm_relocate_functions<big_endian>::thumb_branch_common(
10295 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10296 false);
10297 break;
10298
10299 case elfcpp::R_ARM_PLT32:
10300 case elfcpp::R_ARM_CALL:
10301 case elfcpp::R_ARM_JUMP24:
10302 case elfcpp::R_ARM_XPC25:
10303 reloc_status =
10304 Arm_relocate_functions<big_endian>::arm_branch_common(
10305 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10306 false);
10307 break;
10308
10309 case elfcpp::R_ARM_THM_JUMP19:
10310 reloc_status =
10311 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
10312 psymval, 0, thumb_bit);
10313 break;
10314
10315 case elfcpp::R_ARM_THM_JUMP6:
10316 reloc_status =
10317 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
10318 0);
10319 break;
10320
10321 case elfcpp::R_ARM_THM_JUMP8:
10322 reloc_status =
10323 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
10324 0);
10325 break;
10326
10327 case elfcpp::R_ARM_THM_JUMP11:
10328 reloc_status =
10329 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
10330 0);
10331 break;
10332
10333 case elfcpp::R_ARM_PREL31:
10334 reloc_status =
10335 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
10336 thumb_bit);
10337 break;
10338
10339 case elfcpp::R_ARM_THM_PC8:
10340 reloc_status =
10341 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
10342 0);
10343 break;
10344
10345 case elfcpp::R_ARM_THM_PC12:
10346 reloc_status =
10347 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
10348 0);
10349 break;
10350
10351 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
10352 reloc_status =
10353 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
10354 0, thumb_bit);
10355 break;
10356
10357 // These relocation truncate relocation results so we cannot handle them
10358 // in a relocatable link.
10359 case elfcpp::R_ARM_MOVT_ABS:
10360 case elfcpp::R_ARM_THM_MOVT_ABS:
10361 case elfcpp::R_ARM_MOVT_PREL:
10362 case elfcpp::R_ARM_MOVT_BREL:
10363 case elfcpp::R_ARM_THM_MOVT_PREL:
10364 case elfcpp::R_ARM_THM_MOVT_BREL:
10365 case elfcpp::R_ARM_ALU_PC_G0_NC:
10366 case elfcpp::R_ARM_ALU_PC_G0:
10367 case elfcpp::R_ARM_ALU_PC_G1_NC:
10368 case elfcpp::R_ARM_ALU_PC_G1:
10369 case elfcpp::R_ARM_ALU_PC_G2:
10370 case elfcpp::R_ARM_ALU_SB_G0_NC:
10371 case elfcpp::R_ARM_ALU_SB_G0:
10372 case elfcpp::R_ARM_ALU_SB_G1_NC:
10373 case elfcpp::R_ARM_ALU_SB_G1:
10374 case elfcpp::R_ARM_ALU_SB_G2:
10375 case elfcpp::R_ARM_LDR_PC_G0:
10376 case elfcpp::R_ARM_LDR_PC_G1:
10377 case elfcpp::R_ARM_LDR_PC_G2:
10378 case elfcpp::R_ARM_LDR_SB_G0:
10379 case elfcpp::R_ARM_LDR_SB_G1:
10380 case elfcpp::R_ARM_LDR_SB_G2:
10381 case elfcpp::R_ARM_LDRS_PC_G0:
10382 case elfcpp::R_ARM_LDRS_PC_G1:
10383 case elfcpp::R_ARM_LDRS_PC_G2:
10384 case elfcpp::R_ARM_LDRS_SB_G0:
10385 case elfcpp::R_ARM_LDRS_SB_G1:
10386 case elfcpp::R_ARM_LDRS_SB_G2:
10387 case elfcpp::R_ARM_LDC_PC_G0:
10388 case elfcpp::R_ARM_LDC_PC_G1:
10389 case elfcpp::R_ARM_LDC_PC_G2:
10390 case elfcpp::R_ARM_LDC_SB_G0:
10391 case elfcpp::R_ARM_LDC_SB_G1:
10392 case elfcpp::R_ARM_LDC_SB_G2:
10393 gold_error(_("cannot handle %s in a relocatable link"),
10394 arp->name().c_str());
10395 break;
10396
10397 default:
10398 gold_unreachable();
10399 }
10400
10401 // Report any errors.
10402 switch (reloc_status)
10403 {
10404 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
10405 break;
10406 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
10407 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10408 _("relocation overflow in %s"),
10409 arp->name().c_str());
10410 break;
10411 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
10412 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10413 _("unexpected opcode while processing relocation %s"),
10414 arp->name().c_str());
10415 break;
10416 default:
10417 gold_unreachable();
10418 }
10419 }
10420
10421 // Return the value to use for a dynamic symbol which requires special
10422 // treatment. This is how we support equality comparisons of function
10423 // pointers across shared library boundaries, as described in the
10424 // processor specific ABI supplement.
10425
10426 template<bool big_endian>
10427 uint64_t
10428 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
10429 {
10430 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
10431 return this->plt_address_for_global(gsym);
10432 }
10433
10434 // Map platform-specific relocs to real relocs
10435 //
10436 template<bool big_endian>
10437 unsigned int
10438 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
10439 {
10440 switch (r_type)
10441 {
10442 case elfcpp::R_ARM_TARGET1:
10443 // This is either R_ARM_ABS32 or R_ARM_REL32;
10444 return elfcpp::R_ARM_ABS32;
10445
10446 case elfcpp::R_ARM_TARGET2:
10447 // This can be any reloc type but usually is R_ARM_GOT_PREL
10448 return elfcpp::R_ARM_GOT_PREL;
10449
10450 default:
10451 return r_type;
10452 }
10453 }
10454
10455 // Whether if two EABI versions V1 and V2 are compatible.
10456
10457 template<bool big_endian>
10458 bool
10459 Target_arm<big_endian>::are_eabi_versions_compatible(
10460 elfcpp::Elf_Word v1,
10461 elfcpp::Elf_Word v2)
10462 {
10463 // v4 and v5 are the same spec before and after it was released,
10464 // so allow mixing them.
10465 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
10466 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
10467 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
10468 return true;
10469
10470 return v1 == v2;
10471 }
10472
10473 // Combine FLAGS from an input object called NAME and the processor-specific
10474 // flags in the ELF header of the output. Much of this is adapted from the
10475 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
10476 // in bfd/elf32-arm.c.
10477
10478 template<bool big_endian>
10479 void
10480 Target_arm<big_endian>::merge_processor_specific_flags(
10481 const std::string& name,
10482 elfcpp::Elf_Word flags)
10483 {
10484 if (this->are_processor_specific_flags_set())
10485 {
10486 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
10487
10488 // Nothing to merge if flags equal to those in output.
10489 if (flags == out_flags)
10490 return;
10491
10492 // Complain about various flag mismatches.
10493 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10494 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10495 if (!this->are_eabi_versions_compatible(version1, version2)
10496 && parameters->options().warn_mismatch())
10497 gold_error(_("Source object %s has EABI version %d but output has "
10498 "EABI version %d."),
10499 name.c_str(),
10500 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10501 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10502 }
10503 else
10504 {
10505 // If the input is the default architecture and had the default
10506 // flags then do not bother setting the flags for the output
10507 // architecture, instead allow future merges to do this. If no
10508 // future merges ever set these flags then they will retain their
10509 // uninitialised values, which surprise surprise, correspond
10510 // to the default values.
10511 if (flags == 0)
10512 return;
10513
10514 // This is the first time, just copy the flags.
10515 // We only copy the EABI version for now.
10516 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10517 }
10518 }
10519
10520 // Adjust ELF file header.
10521 template<bool big_endian>
10522 void
10523 Target_arm<big_endian>::do_adjust_elf_header(
10524 unsigned char* view,
10525 int len)
10526 {
10527 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10528
10529 elfcpp::Ehdr<32, big_endian> ehdr(view);
10530 elfcpp::Elf_Word flags = this->processor_specific_flags();
10531 unsigned char e_ident[elfcpp::EI_NIDENT];
10532 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10533
10534 if (elfcpp::arm_eabi_version(flags)
10535 == elfcpp::EF_ARM_EABI_UNKNOWN)
10536 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10537 else
10538 e_ident[elfcpp::EI_OSABI] = 0;
10539 e_ident[elfcpp::EI_ABIVERSION] = 0;
10540
10541 // FIXME: Do EF_ARM_BE8 adjustment.
10542
10543 // If we're working in EABI_VER5, set the hard/soft float ABI flags
10544 // as appropriate.
10545 if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10546 {
10547 elfcpp::Elf_Half type = ehdr.get_e_type();
10548 if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10549 {
10550 Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10551 if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp)
10552 flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10553 else
10554 flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10555 this->set_processor_specific_flags(flags);
10556 }
10557 }
10558 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10559 oehdr.put_e_ident(e_ident);
10560 oehdr.put_e_flags(this->processor_specific_flags());
10561 }
10562
10563 // do_make_elf_object to override the same function in the base class.
10564 // We need to use a target-specific sub-class of
10565 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10566 // Hence we need to have our own ELF object creation.
10567
10568 template<bool big_endian>
10569 Object*
10570 Target_arm<big_endian>::do_make_elf_object(
10571 const std::string& name,
10572 Input_file* input_file,
10573 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10574 {
10575 int et = ehdr.get_e_type();
10576 // ET_EXEC files are valid input for --just-symbols/-R,
10577 // and we treat them as relocatable objects.
10578 if (et == elfcpp::ET_REL
10579 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10580 {
10581 Arm_relobj<big_endian>* obj =
10582 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10583 obj->setup();
10584 return obj;
10585 }
10586 else if (et == elfcpp::ET_DYN)
10587 {
10588 Sized_dynobj<32, big_endian>* obj =
10589 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10590 obj->setup();
10591 return obj;
10592 }
10593 else
10594 {
10595 gold_error(_("%s: unsupported ELF file type %d"),
10596 name.c_str(), et);
10597 return NULL;
10598 }
10599 }
10600
10601 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10602 // Returns -1 if no architecture could be read.
10603 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10604
10605 template<bool big_endian>
10606 int
10607 Target_arm<big_endian>::get_secondary_compatible_arch(
10608 const Attributes_section_data* pasd)
10609 {
10610 const Object_attribute* known_attributes =
10611 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10612
10613 // Note: the tag and its argument below are uleb128 values, though
10614 // currently-defined values fit in one byte for each.
10615 const std::string& sv =
10616 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10617 if (sv.size() == 2
10618 && sv.data()[0] == elfcpp::Tag_CPU_arch
10619 && (sv.data()[1] & 128) != 128)
10620 return sv.data()[1];
10621
10622 // This tag is "safely ignorable", so don't complain if it looks funny.
10623 return -1;
10624 }
10625
10626 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10627 // The tag is removed if ARCH is -1.
10628 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10629
10630 template<bool big_endian>
10631 void
10632 Target_arm<big_endian>::set_secondary_compatible_arch(
10633 Attributes_section_data* pasd,
10634 int arch)
10635 {
10636 Object_attribute* known_attributes =
10637 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10638
10639 if (arch == -1)
10640 {
10641 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10642 return;
10643 }
10644
10645 // Note: the tag and its argument below are uleb128 values, though
10646 // currently-defined values fit in one byte for each.
10647 char sv[3];
10648 sv[0] = elfcpp::Tag_CPU_arch;
10649 gold_assert(arch != 0);
10650 sv[1] = arch;
10651 sv[2] = '\0';
10652
10653 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10654 }
10655
10656 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10657 // into account.
10658 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10659
10660 template<bool big_endian>
10661 int
10662 Target_arm<big_endian>::tag_cpu_arch_combine(
10663 const char* name,
10664 int oldtag,
10665 int* secondary_compat_out,
10666 int newtag,
10667 int secondary_compat)
10668 {
10669 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10670 static const int v6t2[] =
10671 {
10672 T(V6T2), // PRE_V4.
10673 T(V6T2), // V4.
10674 T(V6T2), // V4T.
10675 T(V6T2), // V5T.
10676 T(V6T2), // V5TE.
10677 T(V6T2), // V5TEJ.
10678 T(V6T2), // V6.
10679 T(V7), // V6KZ.
10680 T(V6T2) // V6T2.
10681 };
10682 static const int v6k[] =
10683 {
10684 T(V6K), // PRE_V4.
10685 T(V6K), // V4.
10686 T(V6K), // V4T.
10687 T(V6K), // V5T.
10688 T(V6K), // V5TE.
10689 T(V6K), // V5TEJ.
10690 T(V6K), // V6.
10691 T(V6KZ), // V6KZ.
10692 T(V7), // V6T2.
10693 T(V6K) // V6K.
10694 };
10695 static const int v7[] =
10696 {
10697 T(V7), // PRE_V4.
10698 T(V7), // V4.
10699 T(V7), // V4T.
10700 T(V7), // V5T.
10701 T(V7), // V5TE.
10702 T(V7), // V5TEJ.
10703 T(V7), // V6.
10704 T(V7), // V6KZ.
10705 T(V7), // V6T2.
10706 T(V7), // V6K.
10707 T(V7) // V7.
10708 };
10709 static const int v6_m[] =
10710 {
10711 -1, // PRE_V4.
10712 -1, // V4.
10713 T(V6K), // V4T.
10714 T(V6K), // V5T.
10715 T(V6K), // V5TE.
10716 T(V6K), // V5TEJ.
10717 T(V6K), // V6.
10718 T(V6KZ), // V6KZ.
10719 T(V7), // V6T2.
10720 T(V6K), // V6K.
10721 T(V7), // V7.
10722 T(V6_M) // V6_M.
10723 };
10724 static const int v6s_m[] =
10725 {
10726 -1, // PRE_V4.
10727 -1, // V4.
10728 T(V6K), // V4T.
10729 T(V6K), // V5T.
10730 T(V6K), // V5TE.
10731 T(V6K), // V5TEJ.
10732 T(V6K), // V6.
10733 T(V6KZ), // V6KZ.
10734 T(V7), // V6T2.
10735 T(V6K), // V6K.
10736 T(V7), // V7.
10737 T(V6S_M), // V6_M.
10738 T(V6S_M) // V6S_M.
10739 };
10740 static const int v7e_m[] =
10741 {
10742 -1, // PRE_V4.
10743 -1, // V4.
10744 T(V7E_M), // V4T.
10745 T(V7E_M), // V5T.
10746 T(V7E_M), // V5TE.
10747 T(V7E_M), // V5TEJ.
10748 T(V7E_M), // V6.
10749 T(V7E_M), // V6KZ.
10750 T(V7E_M), // V6T2.
10751 T(V7E_M), // V6K.
10752 T(V7E_M), // V7.
10753 T(V7E_M), // V6_M.
10754 T(V7E_M), // V6S_M.
10755 T(V7E_M) // V7E_M.
10756 };
10757 static const int v8[] =
10758 {
10759 T(V8), // PRE_V4.
10760 T(V8), // V4.
10761 T(V8), // V4T.
10762 T(V8), // V5T.
10763 T(V8), // V5TE.
10764 T(V8), // V5TEJ.
10765 T(V8), // V6.
10766 T(V8), // V6KZ.
10767 T(V8), // V6T2.
10768 T(V8), // V6K.
10769 T(V8), // V7.
10770 T(V8), // V6_M.
10771 T(V8), // V6S_M.
10772 T(V8), // V7E_M.
10773 T(V8) // V8.
10774 };
10775 static const int v4t_plus_v6_m[] =
10776 {
10777 -1, // PRE_V4.
10778 -1, // V4.
10779 T(V4T), // V4T.
10780 T(V5T), // V5T.
10781 T(V5TE), // V5TE.
10782 T(V5TEJ), // V5TEJ.
10783 T(V6), // V6.
10784 T(V6KZ), // V6KZ.
10785 T(V6T2), // V6T2.
10786 T(V6K), // V6K.
10787 T(V7), // V7.
10788 T(V6_M), // V6_M.
10789 T(V6S_M), // V6S_M.
10790 T(V7E_M), // V7E_M.
10791 T(V8), // V8.
10792 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10793 };
10794 static const int* comb[] =
10795 {
10796 v6t2,
10797 v6k,
10798 v7,
10799 v6_m,
10800 v6s_m,
10801 v7e_m,
10802 v8,
10803 // Pseudo-architecture.
10804 v4t_plus_v6_m
10805 };
10806
10807 // Check we've not got a higher architecture than we know about.
10808
10809 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10810 {
10811 gold_error(_("%s: unknown CPU architecture"), name);
10812 return -1;
10813 }
10814
10815 // Override old tag if we have a Tag_also_compatible_with on the output.
10816
10817 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10818 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10819 oldtag = T(V4T_PLUS_V6_M);
10820
10821 // And override the new tag if we have a Tag_also_compatible_with on the
10822 // input.
10823
10824 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10825 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10826 newtag = T(V4T_PLUS_V6_M);
10827
10828 // Architectures before V6KZ add features monotonically.
10829 int tagh = std::max(oldtag, newtag);
10830 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10831 return tagh;
10832
10833 int tagl = std::min(oldtag, newtag);
10834 int result = comb[tagh - T(V6T2)][tagl];
10835
10836 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10837 // as the canonical version.
10838 if (result == T(V4T_PLUS_V6_M))
10839 {
10840 result = T(V4T);
10841 *secondary_compat_out = T(V6_M);
10842 }
10843 else
10844 *secondary_compat_out = -1;
10845
10846 if (result == -1)
10847 {
10848 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10849 name, oldtag, newtag);
10850 return -1;
10851 }
10852
10853 return result;
10854 #undef T
10855 }
10856
10857 // Helper to print AEABI enum tag value.
10858
10859 template<bool big_endian>
10860 std::string
10861 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10862 {
10863 static const char* aeabi_enum_names[] =
10864 { "", "variable-size", "32-bit", "" };
10865 const size_t aeabi_enum_names_size =
10866 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10867
10868 if (value < aeabi_enum_names_size)
10869 return std::string(aeabi_enum_names[value]);
10870 else
10871 {
10872 char buffer[100];
10873 sprintf(buffer, "<unknown value %u>", value);
10874 return std::string(buffer);
10875 }
10876 }
10877
10878 // Return the string value to store in TAG_CPU_name.
10879
10880 template<bool big_endian>
10881 std::string
10882 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10883 {
10884 static const char* name_table[] = {
10885 // These aren't real CPU names, but we can't guess
10886 // that from the architecture version alone.
10887 "Pre v4",
10888 "ARM v4",
10889 "ARM v4T",
10890 "ARM v5T",
10891 "ARM v5TE",
10892 "ARM v5TEJ",
10893 "ARM v6",
10894 "ARM v6KZ",
10895 "ARM v6T2",
10896 "ARM v6K",
10897 "ARM v7",
10898 "ARM v6-M",
10899 "ARM v6S-M",
10900 "ARM v7E-M",
10901 "ARM v8"
10902 };
10903 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10904
10905 if (value < name_table_size)
10906 return std::string(name_table[value]);
10907 else
10908 {
10909 char buffer[100];
10910 sprintf(buffer, "<unknown CPU value %u>", value);
10911 return std::string(buffer);
10912 }
10913 }
10914
10915 // Query attributes object to see if integer divide instructions may be
10916 // present in an object.
10917
10918 template<bool big_endian>
10919 bool
10920 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10921 const Object_attribute* div_attr)
10922 {
10923 switch (div_attr->int_value())
10924 {
10925 case 0:
10926 // Integer divide allowed if instruction contained in
10927 // archetecture.
10928 if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10929 return true;
10930 else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10931 return true;
10932 else
10933 return false;
10934
10935 case 1:
10936 // Integer divide explicitly prohibited.
10937 return false;
10938
10939 default:
10940 // Unrecognised case - treat as allowing divide everywhere.
10941 case 2:
10942 // Integer divide allowed in ARM state.
10943 return true;
10944 }
10945 }
10946
10947 // Query attributes object to see if integer divide instructions are
10948 // forbidden to be in the object. This is not the inverse of
10949 // attributes_accept_div.
10950
10951 template<bool big_endian>
10952 bool
10953 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10954 {
10955 return div_attr->int_value() == 1;
10956 }
10957
10958 // Merge object attributes from input file called NAME with those of the
10959 // output. The input object attributes are in the object pointed by PASD.
10960
10961 template<bool big_endian>
10962 void
10963 Target_arm<big_endian>::merge_object_attributes(
10964 const char* name,
10965 const Attributes_section_data* pasd)
10966 {
10967 // Return if there is no attributes section data.
10968 if (pasd == NULL)
10969 return;
10970
10971 // If output has no object attributes, just copy.
10972 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10973 if (this->attributes_section_data_ == NULL)
10974 {
10975 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10976 Object_attribute* out_attr =
10977 this->attributes_section_data_->known_attributes(vendor);
10978
10979 // We do not output objects with Tag_MPextension_use_legacy - we move
10980 // the attribute's value to Tag_MPextension_use. */
10981 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10982 {
10983 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10984 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10985 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10986 {
10987 gold_error(_("%s has both the current and legacy "
10988 "Tag_MPextension_use attributes"),
10989 name);
10990 }
10991
10992 out_attr[elfcpp::Tag_MPextension_use] =
10993 out_attr[elfcpp::Tag_MPextension_use_legacy];
10994 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10995 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10996 }
10997
10998 return;
10999 }
11000
11001 const Object_attribute* in_attr = pasd->known_attributes(vendor);
11002 Object_attribute* out_attr =
11003 this->attributes_section_data_->known_attributes(vendor);
11004
11005 // This needs to happen before Tag_ABI_FP_number_model is merged. */
11006 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11007 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
11008 {
11009 // Ignore mismatches if the object doesn't use floating point. */
11010 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11011 == elfcpp::AEABI_FP_number_model_none
11012 || (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11013 != elfcpp::AEABI_FP_number_model_none
11014 && out_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11015 == elfcpp::AEABI_VFP_args_compatible))
11016 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
11017 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
11018 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11019 != elfcpp::AEABI_FP_number_model_none
11020 && in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11021 != elfcpp::AEABI_VFP_args_compatible
11022 && parameters->options().warn_mismatch())
11023 gold_error(_("%s uses VFP register arguments, output does not"),
11024 name);
11025 }
11026
11027 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
11028 {
11029 // Merge this attribute with existing attributes.
11030 switch (i)
11031 {
11032 case elfcpp::Tag_CPU_raw_name:
11033 case elfcpp::Tag_CPU_name:
11034 // These are merged after Tag_CPU_arch.
11035 break;
11036
11037 case elfcpp::Tag_ABI_optimization_goals:
11038 case elfcpp::Tag_ABI_FP_optimization_goals:
11039 // Use the first value seen.
11040 break;
11041
11042 case elfcpp::Tag_CPU_arch:
11043 {
11044 unsigned int saved_out_attr = out_attr->int_value();
11045 // Merge Tag_CPU_arch and Tag_also_compatible_with.
11046 int secondary_compat =
11047 this->get_secondary_compatible_arch(pasd);
11048 int secondary_compat_out =
11049 this->get_secondary_compatible_arch(
11050 this->attributes_section_data_);
11051 out_attr[i].set_int_value(
11052 tag_cpu_arch_combine(name, out_attr[i].int_value(),
11053 &secondary_compat_out,
11054 in_attr[i].int_value(),
11055 secondary_compat));
11056 this->set_secondary_compatible_arch(this->attributes_section_data_,
11057 secondary_compat_out);
11058
11059 // Merge Tag_CPU_name and Tag_CPU_raw_name.
11060 if (out_attr[i].int_value() == saved_out_attr)
11061 ; // Leave the names alone.
11062 else if (out_attr[i].int_value() == in_attr[i].int_value())
11063 {
11064 // The output architecture has been changed to match the
11065 // input architecture. Use the input names.
11066 out_attr[elfcpp::Tag_CPU_name].set_string_value(
11067 in_attr[elfcpp::Tag_CPU_name].string_value());
11068 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
11069 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
11070 }
11071 else
11072 {
11073 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
11074 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
11075 }
11076
11077 // If we still don't have a value for Tag_CPU_name,
11078 // make one up now. Tag_CPU_raw_name remains blank.
11079 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
11080 {
11081 const std::string cpu_name =
11082 this->tag_cpu_name_value(out_attr[i].int_value());
11083 // FIXME: If we see an unknown CPU, this will be set
11084 // to "<unknown CPU n>", where n is the attribute value.
11085 // This is different from BFD, which leaves the name alone.
11086 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
11087 }
11088 }
11089 break;
11090
11091 case elfcpp::Tag_ARM_ISA_use:
11092 case elfcpp::Tag_THUMB_ISA_use:
11093 case elfcpp::Tag_WMMX_arch:
11094 case elfcpp::Tag_Advanced_SIMD_arch:
11095 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
11096 case elfcpp::Tag_ABI_FP_rounding:
11097 case elfcpp::Tag_ABI_FP_exceptions:
11098 case elfcpp::Tag_ABI_FP_user_exceptions:
11099 case elfcpp::Tag_ABI_FP_number_model:
11100 case elfcpp::Tag_VFP_HP_extension:
11101 case elfcpp::Tag_CPU_unaligned_access:
11102 case elfcpp::Tag_T2EE_use:
11103 case elfcpp::Tag_Virtualization_use:
11104 case elfcpp::Tag_MPextension_use:
11105 // Use the largest value specified.
11106 if (in_attr[i].int_value() > out_attr[i].int_value())
11107 out_attr[i].set_int_value(in_attr[i].int_value());
11108 break;
11109
11110 case elfcpp::Tag_ABI_align8_preserved:
11111 case elfcpp::Tag_ABI_PCS_RO_data:
11112 // Use the smallest value specified.
11113 if (in_attr[i].int_value() < out_attr[i].int_value())
11114 out_attr[i].set_int_value(in_attr[i].int_value());
11115 break;
11116
11117 case elfcpp::Tag_ABI_align8_needed:
11118 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
11119 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
11120 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
11121 == 0)))
11122 {
11123 // This error message should be enabled once all non-conforming
11124 // binaries in the toolchain have had the attributes set
11125 // properly.
11126 // gold_error(_("output 8-byte data alignment conflicts with %s"),
11127 // name);
11128 }
11129 // Fall through.
11130 case elfcpp::Tag_ABI_FP_denormal:
11131 case elfcpp::Tag_ABI_PCS_GOT_use:
11132 {
11133 // These tags have 0 = don't care, 1 = strong requirement,
11134 // 2 = weak requirement.
11135 static const int order_021[3] = {0, 2, 1};
11136
11137 // Use the "greatest" from the sequence 0, 2, 1, or the largest
11138 // value if greater than 2 (for future-proofing).
11139 if ((in_attr[i].int_value() > 2
11140 && in_attr[i].int_value() > out_attr[i].int_value())
11141 || (in_attr[i].int_value() <= 2
11142 && out_attr[i].int_value() <= 2
11143 && (order_021[in_attr[i].int_value()]
11144 > order_021[out_attr[i].int_value()])))
11145 out_attr[i].set_int_value(in_attr[i].int_value());
11146 }
11147 break;
11148
11149 case elfcpp::Tag_CPU_arch_profile:
11150 if (out_attr[i].int_value() != in_attr[i].int_value())
11151 {
11152 // 0 will merge with anything.
11153 // 'A' and 'S' merge to 'A'.
11154 // 'R' and 'S' merge to 'R'.
11155 // 'M' and 'A|R|S' is an error.
11156 if (out_attr[i].int_value() == 0
11157 || (out_attr[i].int_value() == 'S'
11158 && (in_attr[i].int_value() == 'A'
11159 || in_attr[i].int_value() == 'R')))
11160 out_attr[i].set_int_value(in_attr[i].int_value());
11161 else if (in_attr[i].int_value() == 0
11162 || (in_attr[i].int_value() == 'S'
11163 && (out_attr[i].int_value() == 'A'
11164 || out_attr[i].int_value() == 'R')))
11165 ; // Do nothing.
11166 else if (parameters->options().warn_mismatch())
11167 {
11168 gold_error
11169 (_("conflicting architecture profiles %c/%c"),
11170 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
11171 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
11172 }
11173 }
11174 break;
11175 case elfcpp::Tag_VFP_arch:
11176 {
11177 static const struct
11178 {
11179 int ver;
11180 int regs;
11181 } vfp_versions[7] =
11182 {
11183 {0, 0},
11184 {1, 16},
11185 {2, 16},
11186 {3, 32},
11187 {3, 16},
11188 {4, 32},
11189 {4, 16}
11190 };
11191
11192 // Values greater than 6 aren't defined, so just pick the
11193 // biggest.
11194 if (in_attr[i].int_value() > 6
11195 && in_attr[i].int_value() > out_attr[i].int_value())
11196 {
11197 *out_attr = *in_attr;
11198 break;
11199 }
11200 // The output uses the superset of input features
11201 // (ISA version) and registers.
11202 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
11203 vfp_versions[out_attr[i].int_value()].ver);
11204 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
11205 vfp_versions[out_attr[i].int_value()].regs);
11206 // This assumes all possible supersets are also a valid
11207 // options.
11208 int newval;
11209 for (newval = 6; newval > 0; newval--)
11210 {
11211 if (regs == vfp_versions[newval].regs
11212 && ver == vfp_versions[newval].ver)
11213 break;
11214 }
11215 out_attr[i].set_int_value(newval);
11216 }
11217 break;
11218 case elfcpp::Tag_PCS_config:
11219 if (out_attr[i].int_value() == 0)
11220 out_attr[i].set_int_value(in_attr[i].int_value());
11221 else if (in_attr[i].int_value() != 0
11222 && out_attr[i].int_value() != 0
11223 && parameters->options().warn_mismatch())
11224 {
11225 // It's sometimes ok to mix different configs, so this is only
11226 // a warning.
11227 gold_warning(_("%s: conflicting platform configuration"), name);
11228 }
11229 break;
11230 case elfcpp::Tag_ABI_PCS_R9_use:
11231 if (in_attr[i].int_value() != out_attr[i].int_value()
11232 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
11233 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
11234 && parameters->options().warn_mismatch())
11235 {
11236 gold_error(_("%s: conflicting use of R9"), name);
11237 }
11238 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
11239 out_attr[i].set_int_value(in_attr[i].int_value());
11240 break;
11241 case elfcpp::Tag_ABI_PCS_RW_data:
11242 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
11243 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11244 != elfcpp::AEABI_R9_SB)
11245 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11246 != elfcpp::AEABI_R9_unused)
11247 && parameters->options().warn_mismatch())
11248 {
11249 gold_error(_("%s: SB relative addressing conflicts with use "
11250 "of R9"),
11251 name);
11252 }
11253 // Use the smallest value specified.
11254 if (in_attr[i].int_value() < out_attr[i].int_value())
11255 out_attr[i].set_int_value(in_attr[i].int_value());
11256 break;
11257 case elfcpp::Tag_ABI_PCS_wchar_t:
11258 if (out_attr[i].int_value()
11259 && in_attr[i].int_value()
11260 && out_attr[i].int_value() != in_attr[i].int_value()
11261 && parameters->options().warn_mismatch()
11262 && parameters->options().wchar_size_warning())
11263 {
11264 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
11265 "use %u-byte wchar_t; use of wchar_t values "
11266 "across objects may fail"),
11267 name, in_attr[i].int_value(),
11268 out_attr[i].int_value());
11269 }
11270 else if (in_attr[i].int_value() && !out_attr[i].int_value())
11271 out_attr[i].set_int_value(in_attr[i].int_value());
11272 break;
11273 case elfcpp::Tag_ABI_enum_size:
11274 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
11275 {
11276 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
11277 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
11278 {
11279 // The existing object is compatible with anything.
11280 // Use whatever requirements the new object has.
11281 out_attr[i].set_int_value(in_attr[i].int_value());
11282 }
11283 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
11284 && out_attr[i].int_value() != in_attr[i].int_value()
11285 && parameters->options().warn_mismatch()
11286 && parameters->options().enum_size_warning())
11287 {
11288 unsigned int in_value = in_attr[i].int_value();
11289 unsigned int out_value = out_attr[i].int_value();
11290 gold_warning(_("%s uses %s enums yet the output is to use "
11291 "%s enums; use of enum values across objects "
11292 "may fail"),
11293 name,
11294 this->aeabi_enum_name(in_value).c_str(),
11295 this->aeabi_enum_name(out_value).c_str());
11296 }
11297 }
11298 break;
11299 case elfcpp::Tag_ABI_VFP_args:
11300 // Already done.
11301 break;
11302 case elfcpp::Tag_ABI_WMMX_args:
11303 if (in_attr[i].int_value() != out_attr[i].int_value()
11304 && parameters->options().warn_mismatch())
11305 {
11306 gold_error(_("%s uses iWMMXt register arguments, output does "
11307 "not"),
11308 name);
11309 }
11310 break;
11311 case Object_attribute::Tag_compatibility:
11312 // Merged in target-independent code.
11313 break;
11314 case elfcpp::Tag_ABI_HardFP_use:
11315 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
11316 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
11317 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
11318 out_attr[i].set_int_value(3);
11319 else if (in_attr[i].int_value() > out_attr[i].int_value())
11320 out_attr[i].set_int_value(in_attr[i].int_value());
11321 break;
11322 case elfcpp::Tag_ABI_FP_16bit_format:
11323 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
11324 {
11325 if (in_attr[i].int_value() != out_attr[i].int_value()
11326 && parameters->options().warn_mismatch())
11327 gold_error(_("fp16 format mismatch between %s and output"),
11328 name);
11329 }
11330 if (in_attr[i].int_value() != 0)
11331 out_attr[i].set_int_value(in_attr[i].int_value());
11332 break;
11333
11334 case elfcpp::Tag_DIV_use:
11335 {
11336 // A value of zero on input means that the divide
11337 // instruction may be used if available in the base
11338 // architecture as specified via Tag_CPU_arch and
11339 // Tag_CPU_arch_profile. A value of 1 means that the user
11340 // did not want divide instructions. A value of 2
11341 // explicitly means that divide instructions were allowed
11342 // in ARM and Thumb state.
11343 int arch = this->
11344 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
11345 int_value();
11346 int profile = this->
11347 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
11348 int_value();
11349 if (in_attr[i].int_value() == out_attr[i].int_value())
11350 {
11351 // Do nothing.
11352 }
11353 else if (attributes_forbid_div(&in_attr[i])
11354 && !attributes_accept_div(arch, profile, &out_attr[i]))
11355 out_attr[i].set_int_value(1);
11356 else if (attributes_forbid_div(&out_attr[i])
11357 && attributes_accept_div(arch, profile, &in_attr[i]))
11358 out_attr[i].set_int_value(in_attr[i].int_value());
11359 else if (in_attr[i].int_value() == 2)
11360 out_attr[i].set_int_value(in_attr[i].int_value());
11361 }
11362 break;
11363
11364 case elfcpp::Tag_MPextension_use_legacy:
11365 // We don't output objects with Tag_MPextension_use_legacy - we
11366 // move the value to Tag_MPextension_use.
11367 if (in_attr[i].int_value() != 0
11368 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
11369 {
11370 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
11371 != in_attr[i].int_value())
11372 {
11373 gold_error(_("%s has has both the current and legacy "
11374 "Tag_MPextension_use attributes"),
11375 name);
11376 }
11377 }
11378
11379 if (in_attr[i].int_value()
11380 > out_attr[elfcpp::Tag_MPextension_use].int_value())
11381 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
11382
11383 break;
11384
11385 case elfcpp::Tag_nodefaults:
11386 // This tag is set if it exists, but the value is unused (and is
11387 // typically zero). We don't actually need to do anything here -
11388 // the merge happens automatically when the type flags are merged
11389 // below.
11390 break;
11391 case elfcpp::Tag_also_compatible_with:
11392 // Already done in Tag_CPU_arch.
11393 break;
11394 case elfcpp::Tag_conformance:
11395 // Keep the attribute if it matches. Throw it away otherwise.
11396 // No attribute means no claim to conform.
11397 if (in_attr[i].string_value() != out_attr[i].string_value())
11398 out_attr[i].set_string_value("");
11399 break;
11400
11401 default:
11402 {
11403 const char* err_object = NULL;
11404
11405 // The "known_obj_attributes" table does contain some undefined
11406 // attributes. Ensure that there are unused.
11407 if (out_attr[i].int_value() != 0
11408 || out_attr[i].string_value() != "")
11409 err_object = "output";
11410 else if (in_attr[i].int_value() != 0
11411 || in_attr[i].string_value() != "")
11412 err_object = name;
11413
11414 if (err_object != NULL
11415 && parameters->options().warn_mismatch())
11416 {
11417 // Attribute numbers >=64 (mod 128) can be safely ignored.
11418 if ((i & 127) < 64)
11419 gold_error(_("%s: unknown mandatory EABI object attribute "
11420 "%d"),
11421 err_object, i);
11422 else
11423 gold_warning(_("%s: unknown EABI object attribute %d"),
11424 err_object, i);
11425 }
11426
11427 // Only pass on attributes that match in both inputs.
11428 if (!in_attr[i].matches(out_attr[i]))
11429 {
11430 out_attr[i].set_int_value(0);
11431 out_attr[i].set_string_value("");
11432 }
11433 }
11434 }
11435
11436 // If out_attr was copied from in_attr then it won't have a type yet.
11437 if (in_attr[i].type() && !out_attr[i].type())
11438 out_attr[i].set_type(in_attr[i].type());
11439 }
11440
11441 // Merge Tag_compatibility attributes and any common GNU ones.
11442 this->attributes_section_data_->merge(name, pasd);
11443
11444 // Check for any attributes not known on ARM.
11445 typedef Vendor_object_attributes::Other_attributes Other_attributes;
11446 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
11447 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
11448 Other_attributes* out_other_attributes =
11449 this->attributes_section_data_->other_attributes(vendor);
11450 Other_attributes::iterator out_iter = out_other_attributes->begin();
11451
11452 while (in_iter != in_other_attributes->end()
11453 || out_iter != out_other_attributes->end())
11454 {
11455 const char* err_object = NULL;
11456 int err_tag = 0;
11457
11458 // The tags for each list are in numerical order.
11459 // If the tags are equal, then merge.
11460 if (out_iter != out_other_attributes->end()
11461 && (in_iter == in_other_attributes->end()
11462 || in_iter->first > out_iter->first))
11463 {
11464 // This attribute only exists in output. We can't merge, and we
11465 // don't know what the tag means, so delete it.
11466 err_object = "output";
11467 err_tag = out_iter->first;
11468 int saved_tag = out_iter->first;
11469 delete out_iter->second;
11470 out_other_attributes->erase(out_iter);
11471 out_iter = out_other_attributes->upper_bound(saved_tag);
11472 }
11473 else if (in_iter != in_other_attributes->end()
11474 && (out_iter != out_other_attributes->end()
11475 || in_iter->first < out_iter->first))
11476 {
11477 // This attribute only exists in input. We can't merge, and we
11478 // don't know what the tag means, so ignore it.
11479 err_object = name;
11480 err_tag = in_iter->first;
11481 ++in_iter;
11482 }
11483 else // The tags are equal.
11484 {
11485 // As present, all attributes in the list are unknown, and
11486 // therefore can't be merged meaningfully.
11487 err_object = "output";
11488 err_tag = out_iter->first;
11489
11490 // Only pass on attributes that match in both inputs.
11491 if (!in_iter->second->matches(*(out_iter->second)))
11492 {
11493 // No match. Delete the attribute.
11494 int saved_tag = out_iter->first;
11495 delete out_iter->second;
11496 out_other_attributes->erase(out_iter);
11497 out_iter = out_other_attributes->upper_bound(saved_tag);
11498 }
11499 else
11500 {
11501 // Matched. Keep the attribute and move to the next.
11502 ++out_iter;
11503 ++in_iter;
11504 }
11505 }
11506
11507 if (err_object && parameters->options().warn_mismatch())
11508 {
11509 // Attribute numbers >=64 (mod 128) can be safely ignored. */
11510 if ((err_tag & 127) < 64)
11511 {
11512 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
11513 err_object, err_tag);
11514 }
11515 else
11516 {
11517 gold_warning(_("%s: unknown EABI object attribute %d"),
11518 err_object, err_tag);
11519 }
11520 }
11521 }
11522 }
11523
11524 // Stub-generation methods for Target_arm.
11525
11526 // Make a new Arm_input_section object.
11527
11528 template<bool big_endian>
11529 Arm_input_section<big_endian>*
11530 Target_arm<big_endian>::new_arm_input_section(
11531 Relobj* relobj,
11532 unsigned int shndx)
11533 {
11534 Section_id sid(relobj, shndx);
11535
11536 Arm_input_section<big_endian>* arm_input_section =
11537 new Arm_input_section<big_endian>(relobj, shndx);
11538 arm_input_section->init();
11539
11540 // Register new Arm_input_section in map for look-up.
11541 std::pair<typename Arm_input_section_map::iterator, bool> ins =
11542 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11543
11544 // Make sure that it we have not created another Arm_input_section
11545 // for this input section already.
11546 gold_assert(ins.second);
11547
11548 return arm_input_section;
11549 }
11550
11551 // Find the Arm_input_section object corresponding to the SHNDX-th input
11552 // section of RELOBJ.
11553
11554 template<bool big_endian>
11555 Arm_input_section<big_endian>*
11556 Target_arm<big_endian>::find_arm_input_section(
11557 Relobj* relobj,
11558 unsigned int shndx) const
11559 {
11560 Section_id sid(relobj, shndx);
11561 typename Arm_input_section_map::const_iterator p =
11562 this->arm_input_section_map_.find(sid);
11563 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11564 }
11565
11566 // Make a new stub table.
11567
11568 template<bool big_endian>
11569 Stub_table<big_endian>*
11570 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11571 {
11572 Stub_table<big_endian>* stub_table =
11573 new Stub_table<big_endian>(owner);
11574 this->stub_tables_.push_back(stub_table);
11575
11576 stub_table->set_address(owner->address() + owner->data_size());
11577 stub_table->set_file_offset(owner->offset() + owner->data_size());
11578 stub_table->finalize_data_size();
11579
11580 return stub_table;
11581 }
11582
11583 // Scan a relocation for stub generation.
11584
11585 template<bool big_endian>
11586 void
11587 Target_arm<big_endian>::scan_reloc_for_stub(
11588 const Relocate_info<32, big_endian>* relinfo,
11589 unsigned int r_type,
11590 const Sized_symbol<32>* gsym,
11591 unsigned int r_sym,
11592 const Symbol_value<32>* psymval,
11593 elfcpp::Elf_types<32>::Elf_Swxword addend,
11594 Arm_address address)
11595 {
11596 const Arm_relobj<big_endian>* arm_relobj =
11597 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11598
11599 bool target_is_thumb;
11600 Symbol_value<32> symval;
11601 if (gsym != NULL)
11602 {
11603 // This is a global symbol. Determine if we use PLT and if the
11604 // final target is THUMB.
11605 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11606 {
11607 // This uses a PLT, change the symbol value.
11608 symval.set_output_value(this->plt_address_for_global(gsym));
11609 psymval = &symval;
11610 target_is_thumb = false;
11611 }
11612 else if (gsym->is_undefined())
11613 // There is no need to generate a stub symbol is undefined.
11614 return;
11615 else
11616 {
11617 target_is_thumb =
11618 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11619 || (gsym->type() == elfcpp::STT_FUNC
11620 && !gsym->is_undefined()
11621 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11622 }
11623 }
11624 else
11625 {
11626 // This is a local symbol. Determine if the final target is THUMB.
11627 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11628 }
11629
11630 // Strip LSB if this points to a THUMB target.
11631 const Arm_reloc_property* reloc_property =
11632 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11633 gold_assert(reloc_property != NULL);
11634 if (target_is_thumb
11635 && reloc_property->uses_thumb_bit()
11636 && ((psymval->value(arm_relobj, 0) & 1) != 0))
11637 {
11638 Arm_address stripped_value =
11639 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11640 symval.set_output_value(stripped_value);
11641 psymval = &symval;
11642 }
11643
11644 // Get the symbol value.
11645 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11646
11647 // Owing to pipelining, the PC relative branches below actually skip
11648 // two instructions when the branch offset is 0.
11649 Arm_address destination;
11650 switch (r_type)
11651 {
11652 case elfcpp::R_ARM_CALL:
11653 case elfcpp::R_ARM_JUMP24:
11654 case elfcpp::R_ARM_PLT32:
11655 // ARM branches.
11656 destination = value + addend + 8;
11657 break;
11658 case elfcpp::R_ARM_THM_CALL:
11659 case elfcpp::R_ARM_THM_XPC22:
11660 case elfcpp::R_ARM_THM_JUMP24:
11661 case elfcpp::R_ARM_THM_JUMP19:
11662 // THUMB branches.
11663 destination = value + addend + 4;
11664 break;
11665 default:
11666 gold_unreachable();
11667 }
11668
11669 Reloc_stub* stub = NULL;
11670 Stub_type stub_type =
11671 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11672 target_is_thumb);
11673 if (stub_type != arm_stub_none)
11674 {
11675 // Try looking up an existing stub from a stub table.
11676 Stub_table<big_endian>* stub_table =
11677 arm_relobj->stub_table(relinfo->data_shndx);
11678 gold_assert(stub_table != NULL);
11679
11680 // Locate stub by destination.
11681 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11682
11683 // Create a stub if there is not one already
11684 stub = stub_table->find_reloc_stub(stub_key);
11685 if (stub == NULL)
11686 {
11687 // create a new stub and add it to stub table.
11688 stub = this->stub_factory().make_reloc_stub(stub_type);
11689 stub_table->add_reloc_stub(stub, stub_key);
11690 }
11691
11692 // Record the destination address.
11693 stub->set_destination_address(destination
11694 | (target_is_thumb ? 1 : 0));
11695 }
11696
11697 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11698 if (this->fix_cortex_a8_
11699 && (r_type == elfcpp::R_ARM_THM_JUMP24
11700 || r_type == elfcpp::R_ARM_THM_JUMP19
11701 || r_type == elfcpp::R_ARM_THM_CALL
11702 || r_type == elfcpp::R_ARM_THM_XPC22)
11703 && (address & 0xfffU) == 0xffeU)
11704 {
11705 // Found a candidate. Note we haven't checked the destination is
11706 // within 4K here: if we do so (and don't create a record) we can't
11707 // tell that a branch should have been relocated when scanning later.
11708 this->cortex_a8_relocs_info_[address] =
11709 new Cortex_a8_reloc(stub, r_type,
11710 destination | (target_is_thumb ? 1 : 0));
11711 }
11712 }
11713
11714 // This function scans a relocation sections for stub generation.
11715 // The template parameter Relocate must be a class type which provides
11716 // a single function, relocate(), which implements the machine
11717 // specific part of a relocation.
11718
11719 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11720 // SHT_REL or SHT_RELA.
11721
11722 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11723 // of relocs. OUTPUT_SECTION is the output section.
11724 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11725 // mapped to output offsets.
11726
11727 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11728 // VIEW_SIZE is the size. These refer to the input section, unless
11729 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11730 // the output section.
11731
11732 template<bool big_endian>
11733 template<int sh_type>
11734 void inline
11735 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11736 const Relocate_info<32, big_endian>* relinfo,
11737 const unsigned char* prelocs,
11738 size_t reloc_count,
11739 Output_section* output_section,
11740 bool needs_special_offset_handling,
11741 const unsigned char* view,
11742 elfcpp::Elf_types<32>::Elf_Addr view_address,
11743 section_size_type)
11744 {
11745 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11746 const int reloc_size =
11747 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11748
11749 Arm_relobj<big_endian>* arm_object =
11750 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11751 unsigned int local_count = arm_object->local_symbol_count();
11752
11753 gold::Default_comdat_behavior default_comdat_behavior;
11754 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11755
11756 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11757 {
11758 Reltype reloc(prelocs);
11759
11760 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11761 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11762 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11763
11764 r_type = this->get_real_reloc_type(r_type);
11765
11766 // Only a few relocation types need stubs.
11767 if ((r_type != elfcpp::R_ARM_CALL)
11768 && (r_type != elfcpp::R_ARM_JUMP24)
11769 && (r_type != elfcpp::R_ARM_PLT32)
11770 && (r_type != elfcpp::R_ARM_THM_CALL)
11771 && (r_type != elfcpp::R_ARM_THM_XPC22)
11772 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11773 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11774 && (r_type != elfcpp::R_ARM_V4BX))
11775 continue;
11776
11777 section_offset_type offset =
11778 convert_to_section_size_type(reloc.get_r_offset());
11779
11780 if (needs_special_offset_handling)
11781 {
11782 offset = output_section->output_offset(relinfo->object,
11783 relinfo->data_shndx,
11784 offset);
11785 if (offset == -1)
11786 continue;
11787 }
11788
11789 // Create a v4bx stub if --fix-v4bx-interworking is used.
11790 if (r_type == elfcpp::R_ARM_V4BX)
11791 {
11792 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11793 {
11794 // Get the BX instruction.
11795 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11796 const Valtype* wv =
11797 reinterpret_cast<const Valtype*>(view + offset);
11798 elfcpp::Elf_types<32>::Elf_Swxword insn =
11799 elfcpp::Swap<32, big_endian>::readval(wv);
11800 const uint32_t reg = (insn & 0xf);
11801
11802 if (reg < 0xf)
11803 {
11804 // Try looking up an existing stub from a stub table.
11805 Stub_table<big_endian>* stub_table =
11806 arm_object->stub_table(relinfo->data_shndx);
11807 gold_assert(stub_table != NULL);
11808
11809 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11810 {
11811 // create a new stub and add it to stub table.
11812 Arm_v4bx_stub* stub =
11813 this->stub_factory().make_arm_v4bx_stub(reg);
11814 gold_assert(stub != NULL);
11815 stub_table->add_arm_v4bx_stub(stub);
11816 }
11817 }
11818 }
11819 continue;
11820 }
11821
11822 // Get the addend.
11823 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11824 elfcpp::Elf_types<32>::Elf_Swxword addend =
11825 stub_addend_reader(r_type, view + offset, reloc);
11826
11827 const Sized_symbol<32>* sym;
11828
11829 Symbol_value<32> symval;
11830 const Symbol_value<32> *psymval;
11831 bool is_defined_in_discarded_section;
11832 unsigned int shndx;
11833 if (r_sym < local_count)
11834 {
11835 sym = NULL;
11836 psymval = arm_object->local_symbol(r_sym);
11837
11838 // If the local symbol belongs to a section we are discarding,
11839 // and that section is a debug section, try to find the
11840 // corresponding kept section and map this symbol to its
11841 // counterpart in the kept section. The symbol must not
11842 // correspond to a section we are folding.
11843 bool is_ordinary;
11844 shndx = psymval->input_shndx(&is_ordinary);
11845 is_defined_in_discarded_section =
11846 (is_ordinary
11847 && shndx != elfcpp::SHN_UNDEF
11848 && !arm_object->is_section_included(shndx)
11849 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11850
11851 // We need to compute the would-be final value of this local
11852 // symbol.
11853 if (!is_defined_in_discarded_section)
11854 {
11855 typedef Sized_relobj_file<32, big_endian> ObjType;
11856 typename ObjType::Compute_final_local_value_status status =
11857 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11858 relinfo->symtab);
11859 if (status == ObjType::CFLV_OK)
11860 {
11861 // Currently we cannot handle a branch to a target in
11862 // a merged section. If this is the case, issue an error
11863 // and also free the merge symbol value.
11864 if (!symval.has_output_value())
11865 {
11866 const std::string& section_name =
11867 arm_object->section_name(shndx);
11868 arm_object->error(_("cannot handle branch to local %u "
11869 "in a merged section %s"),
11870 r_sym, section_name.c_str());
11871 }
11872 psymval = &symval;
11873 }
11874 else
11875 {
11876 // We cannot determine the final value.
11877 continue;
11878 }
11879 }
11880 }
11881 else
11882 {
11883 const Symbol* gsym;
11884 gsym = arm_object->global_symbol(r_sym);
11885 gold_assert(gsym != NULL);
11886 if (gsym->is_forwarder())
11887 gsym = relinfo->symtab->resolve_forwards(gsym);
11888
11889 sym = static_cast<const Sized_symbol<32>*>(gsym);
11890 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11891 symval.set_output_symtab_index(sym->symtab_index());
11892 else
11893 symval.set_no_output_symtab_entry();
11894
11895 // We need to compute the would-be final value of this global
11896 // symbol.
11897 const Symbol_table* symtab = relinfo->symtab;
11898 const Sized_symbol<32>* sized_symbol =
11899 symtab->get_sized_symbol<32>(gsym);
11900 Symbol_table::Compute_final_value_status status;
11901 Arm_address value =
11902 symtab->compute_final_value<32>(sized_symbol, &status);
11903
11904 // Skip this if the symbol has not output section.
11905 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11906 continue;
11907 symval.set_output_value(value);
11908
11909 if (gsym->type() == elfcpp::STT_TLS)
11910 symval.set_is_tls_symbol();
11911 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11912 symval.set_is_ifunc_symbol();
11913 psymval = &symval;
11914
11915 is_defined_in_discarded_section =
11916 (gsym->is_defined_in_discarded_section()
11917 && gsym->is_undefined());
11918 shndx = 0;
11919 }
11920
11921 Symbol_value<32> symval2;
11922 if (is_defined_in_discarded_section)
11923 {
11924 if (comdat_behavior == CB_UNDETERMINED)
11925 {
11926 std::string name = arm_object->section_name(relinfo->data_shndx);
11927 comdat_behavior = default_comdat_behavior.get(name.c_str());
11928 }
11929 if (comdat_behavior == CB_PRETEND)
11930 {
11931 // FIXME: This case does not work for global symbols.
11932 // We have no place to store the original section index.
11933 // Fortunately this does not matter for comdat sections,
11934 // only for sections explicitly discarded by a linker
11935 // script.
11936 bool found;
11937 typename elfcpp::Elf_types<32>::Elf_Addr value =
11938 arm_object->map_to_kept_section(shndx, &found);
11939 if (found)
11940 symval2.set_output_value(value + psymval->input_value());
11941 else
11942 symval2.set_output_value(0);
11943 }
11944 else
11945 {
11946 if (comdat_behavior == CB_WARNING)
11947 gold_warning_at_location(relinfo, i, offset,
11948 _("relocation refers to discarded "
11949 "section"));
11950 symval2.set_output_value(0);
11951 }
11952 symval2.set_no_output_symtab_entry();
11953 psymval = &symval2;
11954 }
11955
11956 // If symbol is a section symbol, we don't know the actual type of
11957 // destination. Give up.
11958 if (psymval->is_section_symbol())
11959 continue;
11960
11961 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11962 addend, view_address + offset);
11963 }
11964 }
11965
11966 // Scan an input section for stub generation.
11967
11968 template<bool big_endian>
11969 void
11970 Target_arm<big_endian>::scan_section_for_stubs(
11971 const Relocate_info<32, big_endian>* relinfo,
11972 unsigned int sh_type,
11973 const unsigned char* prelocs,
11974 size_t reloc_count,
11975 Output_section* output_section,
11976 bool needs_special_offset_handling,
11977 const unsigned char* view,
11978 Arm_address view_address,
11979 section_size_type view_size)
11980 {
11981 if (sh_type == elfcpp::SHT_REL)
11982 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11983 relinfo,
11984 prelocs,
11985 reloc_count,
11986 output_section,
11987 needs_special_offset_handling,
11988 view,
11989 view_address,
11990 view_size);
11991 else if (sh_type == elfcpp::SHT_RELA)
11992 // We do not support RELA type relocations yet. This is provided for
11993 // completeness.
11994 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11995 relinfo,
11996 prelocs,
11997 reloc_count,
11998 output_section,
11999 needs_special_offset_handling,
12000 view,
12001 view_address,
12002 view_size);
12003 else
12004 gold_unreachable();
12005 }
12006
12007 // Group input sections for stub generation.
12008 //
12009 // We group input sections in an output section so that the total size,
12010 // including any padding space due to alignment is smaller than GROUP_SIZE
12011 // unless the only input section in group is bigger than GROUP_SIZE already.
12012 // Then an ARM stub table is created to follow the last input section
12013 // in group. For each group an ARM stub table is created an is placed
12014 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
12015 // extend the group after the stub table.
12016
12017 template<bool big_endian>
12018 void
12019 Target_arm<big_endian>::group_sections(
12020 Layout* layout,
12021 section_size_type group_size,
12022 bool stubs_always_after_branch,
12023 const Task* task)
12024 {
12025 // Group input sections and insert stub table
12026 Layout::Section_list section_list;
12027 layout->get_executable_sections(&section_list);
12028 for (Layout::Section_list::const_iterator p = section_list.begin();
12029 p != section_list.end();
12030 ++p)
12031 {
12032 Arm_output_section<big_endian>* output_section =
12033 Arm_output_section<big_endian>::as_arm_output_section(*p);
12034 output_section->group_sections(group_size, stubs_always_after_branch,
12035 this, task);
12036 }
12037 }
12038
12039 // Relaxation hook. This is where we do stub generation.
12040
12041 template<bool big_endian>
12042 bool
12043 Target_arm<big_endian>::do_relax(
12044 int pass,
12045 const Input_objects* input_objects,
12046 Symbol_table* symtab,
12047 Layout* layout,
12048 const Task* task)
12049 {
12050 // No need to generate stubs if this is a relocatable link.
12051 gold_assert(!parameters->options().relocatable());
12052
12053 // If this is the first pass, we need to group input sections into
12054 // stub groups.
12055 bool done_exidx_fixup = false;
12056 typedef typename Stub_table_list::iterator Stub_table_iterator;
12057 if (pass == 1)
12058 {
12059 // Determine the stub group size. The group size is the absolute
12060 // value of the parameter --stub-group-size. If --stub-group-size
12061 // is passed a negative value, we restrict stubs to be always after
12062 // the stubbed branches.
12063 int32_t stub_group_size_param =
12064 parameters->options().stub_group_size();
12065 bool stubs_always_after_branch = stub_group_size_param < 0;
12066 section_size_type stub_group_size = abs(stub_group_size_param);
12067
12068 if (stub_group_size == 1)
12069 {
12070 // Default value.
12071 // Thumb branch range is +-4MB has to be used as the default
12072 // maximum size (a given section can contain both ARM and Thumb
12073 // code, so the worst case has to be taken into account). If we are
12074 // fixing cortex-a8 errata, the branch range has to be even smaller,
12075 // since wide conditional branch has a range of +-1MB only.
12076 //
12077 // This value is 48K less than that, which allows for 4096
12078 // 12-byte stubs. If we exceed that, then we will fail to link.
12079 // The user will have to relink with an explicit group size
12080 // option.
12081 stub_group_size = 4145152;
12082 }
12083
12084 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
12085 // page as the first half of a 32-bit branch straddling two 4K pages.
12086 // This is a crude way of enforcing that. In addition, long conditional
12087 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
12088 // erratum, limit the group size to (1M - 12k) to avoid unreachable
12089 // cortex-A8 stubs from long conditional branches.
12090 if (this->fix_cortex_a8_)
12091 {
12092 stubs_always_after_branch = true;
12093 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
12094 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
12095 }
12096
12097 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
12098
12099 // Also fix .ARM.exidx section coverage.
12100 Arm_output_section<big_endian>* exidx_output_section = NULL;
12101 for (Layout::Section_list::const_iterator p =
12102 layout->section_list().begin();
12103 p != layout->section_list().end();
12104 ++p)
12105 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
12106 {
12107 if (exidx_output_section == NULL)
12108 exidx_output_section =
12109 Arm_output_section<big_endian>::as_arm_output_section(*p);
12110 else
12111 // We cannot handle this now.
12112 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
12113 "non-relocatable link"),
12114 exidx_output_section->name(),
12115 (*p)->name());
12116 }
12117
12118 if (exidx_output_section != NULL)
12119 {
12120 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
12121 symtab, task);
12122 done_exidx_fixup = true;
12123 }
12124 }
12125 else
12126 {
12127 // If this is not the first pass, addresses and file offsets have
12128 // been reset at this point, set them here.
12129 for (Stub_table_iterator sp = this->stub_tables_.begin();
12130 sp != this->stub_tables_.end();
12131 ++sp)
12132 {
12133 Arm_input_section<big_endian>* owner = (*sp)->owner();
12134 off_t off = align_address(owner->original_size(),
12135 (*sp)->addralign());
12136 (*sp)->set_address_and_file_offset(owner->address() + off,
12137 owner->offset() + off);
12138 }
12139 }
12140
12141 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
12142 // beginning of each relaxation pass, just blow away all the stubs.
12143 // Alternatively, we could selectively remove only the stubs and reloc
12144 // information for code sections that have moved since the last pass.
12145 // That would require more book-keeping.
12146 if (this->fix_cortex_a8_)
12147 {
12148 // Clear all Cortex-A8 reloc information.
12149 for (typename Cortex_a8_relocs_info::const_iterator p =
12150 this->cortex_a8_relocs_info_.begin();
12151 p != this->cortex_a8_relocs_info_.end();
12152 ++p)
12153 delete p->second;
12154 this->cortex_a8_relocs_info_.clear();
12155
12156 // Remove all Cortex-A8 stubs.
12157 for (Stub_table_iterator sp = this->stub_tables_.begin();
12158 sp != this->stub_tables_.end();
12159 ++sp)
12160 (*sp)->remove_all_cortex_a8_stubs();
12161 }
12162
12163 // Scan relocs for relocation stubs
12164 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12165 op != input_objects->relobj_end();
12166 ++op)
12167 {
12168 Arm_relobj<big_endian>* arm_relobj =
12169 Arm_relobj<big_endian>::as_arm_relobj(*op);
12170 // Lock the object so we can read from it. This is only called
12171 // single-threaded from Layout::finalize, so it is OK to lock.
12172 Task_lock_obj<Object> tl(task, arm_relobj);
12173 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
12174 }
12175
12176 // Check all stub tables to see if any of them have their data sizes
12177 // or addresses alignments changed. These are the only things that
12178 // matter.
12179 bool any_stub_table_changed = false;
12180 Unordered_set<const Output_section*> sections_needing_adjustment;
12181 for (Stub_table_iterator sp = this->stub_tables_.begin();
12182 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12183 ++sp)
12184 {
12185 if ((*sp)->update_data_size_and_addralign())
12186 {
12187 // Update data size of stub table owner.
12188 Arm_input_section<big_endian>* owner = (*sp)->owner();
12189 uint64_t address = owner->address();
12190 off_t offset = owner->offset();
12191 owner->reset_address_and_file_offset();
12192 owner->set_address_and_file_offset(address, offset);
12193
12194 sections_needing_adjustment.insert(owner->output_section());
12195 any_stub_table_changed = true;
12196 }
12197 }
12198
12199 // Output_section_data::output_section() returns a const pointer but we
12200 // need to update output sections, so we record all output sections needing
12201 // update above and scan the sections here to find out what sections need
12202 // to be updated.
12203 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
12204 p != layout->section_list().end();
12205 ++p)
12206 {
12207 if (sections_needing_adjustment.find(*p)
12208 != sections_needing_adjustment.end())
12209 (*p)->set_section_offsets_need_adjustment();
12210 }
12211
12212 // Stop relaxation if no EXIDX fix-up and no stub table change.
12213 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
12214
12215 // Finalize the stubs in the last relaxation pass.
12216 if (!continue_relaxation)
12217 {
12218 for (Stub_table_iterator sp = this->stub_tables_.begin();
12219 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12220 ++sp)
12221 (*sp)->finalize_stubs();
12222
12223 // Update output local symbol counts of objects if necessary.
12224 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12225 op != input_objects->relobj_end();
12226 ++op)
12227 {
12228 Arm_relobj<big_endian>* arm_relobj =
12229 Arm_relobj<big_endian>::as_arm_relobj(*op);
12230
12231 // Update output local symbol counts. We need to discard local
12232 // symbols defined in parts of input sections that are discarded by
12233 // relaxation.
12234 if (arm_relobj->output_local_symbol_count_needs_update())
12235 {
12236 // We need to lock the object's file to update it.
12237 Task_lock_obj<Object> tl(task, arm_relobj);
12238 arm_relobj->update_output_local_symbol_count();
12239 }
12240 }
12241 }
12242
12243 return continue_relaxation;
12244 }
12245
12246 // Relocate a stub.
12247
12248 template<bool big_endian>
12249 void
12250 Target_arm<big_endian>::relocate_stub(
12251 Stub* stub,
12252 const Relocate_info<32, big_endian>* relinfo,
12253 Output_section* output_section,
12254 unsigned char* view,
12255 Arm_address address,
12256 section_size_type view_size)
12257 {
12258 Relocate relocate;
12259 const Stub_template* stub_template = stub->stub_template();
12260 for (size_t i = 0; i < stub_template->reloc_count(); i++)
12261 {
12262 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
12263 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
12264
12265 unsigned int r_type = insn->r_type();
12266 section_size_type reloc_offset = stub_template->reloc_offset(i);
12267 section_size_type reloc_size = insn->size();
12268 gold_assert(reloc_offset + reloc_size <= view_size);
12269
12270 // This is the address of the stub destination.
12271 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
12272 Symbol_value<32> symval;
12273 symval.set_output_value(target);
12274
12275 // Synthesize a fake reloc just in case. We don't have a symbol so
12276 // we use 0.
12277 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
12278 memset(reloc_buffer, 0, sizeof(reloc_buffer));
12279 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
12280 reloc_write.put_r_offset(reloc_offset);
12281 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
12282 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
12283
12284 relocate.relocate(relinfo, this, output_section,
12285 this->fake_relnum_for_stubs, rel, r_type,
12286 NULL, &symval, view + reloc_offset,
12287 address + reloc_offset, reloc_size);
12288 }
12289 }
12290
12291 // Determine whether an object attribute tag takes an integer, a
12292 // string or both.
12293
12294 template<bool big_endian>
12295 int
12296 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
12297 {
12298 if (tag == Object_attribute::Tag_compatibility)
12299 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12300 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
12301 else if (tag == elfcpp::Tag_nodefaults)
12302 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12303 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
12304 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
12305 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
12306 else if (tag < 32)
12307 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
12308 else
12309 return ((tag & 1) != 0
12310 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
12311 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
12312 }
12313
12314 // Reorder attributes.
12315 //
12316 // The ABI defines that Tag_conformance should be emitted first, and that
12317 // Tag_nodefaults should be second (if either is defined). This sets those
12318 // two positions, and bumps up the position of all the remaining tags to
12319 // compensate.
12320
12321 template<bool big_endian>
12322 int
12323 Target_arm<big_endian>::do_attributes_order(int num) const
12324 {
12325 // Reorder the known object attributes in output. We want to move
12326 // Tag_conformance to position 4 and Tag_conformance to position 5
12327 // and shift everything between 4 .. Tag_conformance - 1 to make room.
12328 if (num == 4)
12329 return elfcpp::Tag_conformance;
12330 if (num == 5)
12331 return elfcpp::Tag_nodefaults;
12332 if ((num - 2) < elfcpp::Tag_nodefaults)
12333 return num - 2;
12334 if ((num - 1) < elfcpp::Tag_conformance)
12335 return num - 1;
12336 return num;
12337 }
12338
12339 // Scan a span of THUMB code for Cortex-A8 erratum.
12340
12341 template<bool big_endian>
12342 void
12343 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
12344 Arm_relobj<big_endian>* arm_relobj,
12345 unsigned int shndx,
12346 section_size_type span_start,
12347 section_size_type span_end,
12348 const unsigned char* view,
12349 Arm_address address)
12350 {
12351 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
12352 //
12353 // The opcode is BLX.W, BL.W, B.W, Bcc.W
12354 // The branch target is in the same 4KB region as the
12355 // first half of the branch.
12356 // The instruction before the branch is a 32-bit
12357 // length non-branch instruction.
12358 section_size_type i = span_start;
12359 bool last_was_32bit = false;
12360 bool last_was_branch = false;
12361 while (i < span_end)
12362 {
12363 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12364 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
12365 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
12366 bool is_blx = false, is_b = false;
12367 bool is_bl = false, is_bcc = false;
12368
12369 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
12370 if (insn_32bit)
12371 {
12372 // Load the rest of the insn (in manual-friendly order).
12373 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
12374
12375 // Encoding T4: B<c>.W.
12376 is_b = (insn & 0xf800d000U) == 0xf0009000U;
12377 // Encoding T1: BL<c>.W.
12378 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
12379 // Encoding T2: BLX<c>.W.
12380 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
12381 // Encoding T3: B<c>.W (not permitted in IT block).
12382 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
12383 && (insn & 0x07f00000U) != 0x03800000U);
12384 }
12385
12386 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
12387
12388 // If this instruction is a 32-bit THUMB branch that crosses a 4K
12389 // page boundary and it follows 32-bit non-branch instruction,
12390 // we need to work around.
12391 if (is_32bit_branch
12392 && ((address + i) & 0xfffU) == 0xffeU
12393 && last_was_32bit
12394 && !last_was_branch)
12395 {
12396 // Check to see if there is a relocation stub for this branch.
12397 bool force_target_arm = false;
12398 bool force_target_thumb = false;
12399 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
12400 Cortex_a8_relocs_info::const_iterator p =
12401 this->cortex_a8_relocs_info_.find(address + i);
12402
12403 if (p != this->cortex_a8_relocs_info_.end())
12404 {
12405 cortex_a8_reloc = p->second;
12406 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
12407
12408 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12409 && !target_is_thumb)
12410 force_target_arm = true;
12411 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12412 && target_is_thumb)
12413 force_target_thumb = true;
12414 }
12415
12416 off_t offset;
12417 Stub_type stub_type = arm_stub_none;
12418
12419 // Check if we have an offending branch instruction.
12420 uint16_t upper_insn = (insn >> 16) & 0xffffU;
12421 uint16_t lower_insn = insn & 0xffffU;
12422 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12423
12424 if (cortex_a8_reloc != NULL
12425 && cortex_a8_reloc->reloc_stub() != NULL)
12426 // We've already made a stub for this instruction, e.g.
12427 // it's a long branch or a Thumb->ARM stub. Assume that
12428 // stub will suffice to work around the A8 erratum (see
12429 // setting of always_after_branch above).
12430 ;
12431 else if (is_bcc)
12432 {
12433 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
12434 lower_insn);
12435 stub_type = arm_stub_a8_veneer_b_cond;
12436 }
12437 else if (is_b || is_bl || is_blx)
12438 {
12439 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
12440 lower_insn);
12441 if (is_blx)
12442 offset &= ~3;
12443
12444 stub_type = (is_blx
12445 ? arm_stub_a8_veneer_blx
12446 : (is_bl
12447 ? arm_stub_a8_veneer_bl
12448 : arm_stub_a8_veneer_b));
12449 }
12450
12451 if (stub_type != arm_stub_none)
12452 {
12453 Arm_address pc_for_insn = address + i + 4;
12454
12455 // The original instruction is a BL, but the target is
12456 // an ARM instruction. If we were not making a stub,
12457 // the BL would have been converted to a BLX. Use the
12458 // BLX stub instead in that case.
12459 if (this->may_use_v5t_interworking() && force_target_arm
12460 && stub_type == arm_stub_a8_veneer_bl)
12461 {
12462 stub_type = arm_stub_a8_veneer_blx;
12463 is_blx = true;
12464 is_bl = false;
12465 }
12466 // Conversely, if the original instruction was
12467 // BLX but the target is Thumb mode, use the BL stub.
12468 else if (force_target_thumb
12469 && stub_type == arm_stub_a8_veneer_blx)
12470 {
12471 stub_type = arm_stub_a8_veneer_bl;
12472 is_blx = false;
12473 is_bl = true;
12474 }
12475
12476 if (is_blx)
12477 pc_for_insn &= ~3;
12478
12479 // If we found a relocation, use the proper destination,
12480 // not the offset in the (unrelocated) instruction.
12481 // Note this is always done if we switched the stub type above.
12482 if (cortex_a8_reloc != NULL)
12483 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
12484
12485 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
12486
12487 // Add a new stub if destination address in in the same page.
12488 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
12489 {
12490 Cortex_a8_stub* stub =
12491 this->stub_factory_.make_cortex_a8_stub(stub_type,
12492 arm_relobj, shndx,
12493 address + i,
12494 target, insn);
12495 Stub_table<big_endian>* stub_table =
12496 arm_relobj->stub_table(shndx);
12497 gold_assert(stub_table != NULL);
12498 stub_table->add_cortex_a8_stub(address + i, stub);
12499 }
12500 }
12501 }
12502
12503 i += insn_32bit ? 4 : 2;
12504 last_was_32bit = insn_32bit;
12505 last_was_branch = is_32bit_branch;
12506 }
12507 }
12508
12509 // Apply the Cortex-A8 workaround.
12510
12511 template<bool big_endian>
12512 void
12513 Target_arm<big_endian>::apply_cortex_a8_workaround(
12514 const Cortex_a8_stub* stub,
12515 Arm_address stub_address,
12516 unsigned char* insn_view,
12517 Arm_address insn_address)
12518 {
12519 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12520 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12521 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12522 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12523 off_t branch_offset = stub_address - (insn_address + 4);
12524
12525 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12526 switch (stub->stub_template()->type())
12527 {
12528 case arm_stub_a8_veneer_b_cond:
12529 // For a conditional branch, we re-write it to be an unconditional
12530 // branch to the stub. We use the THUMB-2 encoding here.
12531 upper_insn = 0xf000U;
12532 lower_insn = 0xb800U;
12533 // Fall through
12534 case arm_stub_a8_veneer_b:
12535 case arm_stub_a8_veneer_bl:
12536 case arm_stub_a8_veneer_blx:
12537 if ((lower_insn & 0x5000U) == 0x4000U)
12538 // For a BLX instruction, make sure that the relocation is
12539 // rounded up to a word boundary. This follows the semantics of
12540 // the instruction which specifies that bit 1 of the target
12541 // address will come from bit 1 of the base address.
12542 branch_offset = (branch_offset + 2) & ~3;
12543
12544 // Put BRANCH_OFFSET back into the insn.
12545 gold_assert(!Bits<25>::has_overflow32(branch_offset));
12546 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12547 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12548 break;
12549
12550 default:
12551 gold_unreachable();
12552 }
12553
12554 // Put the relocated value back in the object file:
12555 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12556 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12557 }
12558
12559 // Target selector for ARM. Note this is never instantiated directly.
12560 // It's only used in Target_selector_arm_nacl, below.
12561
12562 template<bool big_endian>
12563 class Target_selector_arm : public Target_selector
12564 {
12565 public:
12566 Target_selector_arm()
12567 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12568 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12569 (big_endian ? "armelfb" : "armelf"))
12570 { }
12571
12572 Target*
12573 do_instantiate_target()
12574 { return new Target_arm<big_endian>(); }
12575 };
12576
12577 // Fix .ARM.exidx section coverage.
12578
12579 template<bool big_endian>
12580 void
12581 Target_arm<big_endian>::fix_exidx_coverage(
12582 Layout* layout,
12583 const Input_objects* input_objects,
12584 Arm_output_section<big_endian>* exidx_section,
12585 Symbol_table* symtab,
12586 const Task* task)
12587 {
12588 // We need to look at all the input sections in output in ascending
12589 // order of of output address. We do that by building a sorted list
12590 // of output sections by addresses. Then we looks at the output sections
12591 // in order. The input sections in an output section are already sorted
12592 // by addresses within the output section.
12593
12594 typedef std::set<Output_section*, output_section_address_less_than>
12595 Sorted_output_section_list;
12596 Sorted_output_section_list sorted_output_sections;
12597
12598 // Find out all the output sections of input sections pointed by
12599 // EXIDX input sections.
12600 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12601 p != input_objects->relobj_end();
12602 ++p)
12603 {
12604 Arm_relobj<big_endian>* arm_relobj =
12605 Arm_relobj<big_endian>::as_arm_relobj(*p);
12606 std::vector<unsigned int> shndx_list;
12607 arm_relobj->get_exidx_shndx_list(&shndx_list);
12608 for (size_t i = 0; i < shndx_list.size(); ++i)
12609 {
12610 const Arm_exidx_input_section* exidx_input_section =
12611 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12612 gold_assert(exidx_input_section != NULL);
12613 if (!exidx_input_section->has_errors())
12614 {
12615 unsigned int text_shndx = exidx_input_section->link();
12616 Output_section* os = arm_relobj->output_section(text_shndx);
12617 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12618 sorted_output_sections.insert(os);
12619 }
12620 }
12621 }
12622
12623 // Go over the output sections in ascending order of output addresses.
12624 typedef typename Arm_output_section<big_endian>::Text_section_list
12625 Text_section_list;
12626 Text_section_list sorted_text_sections;
12627 for (typename Sorted_output_section_list::iterator p =
12628 sorted_output_sections.begin();
12629 p != sorted_output_sections.end();
12630 ++p)
12631 {
12632 Arm_output_section<big_endian>* arm_output_section =
12633 Arm_output_section<big_endian>::as_arm_output_section(*p);
12634 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12635 }
12636
12637 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12638 merge_exidx_entries(), task);
12639 }
12640
12641 template<bool big_endian>
12642 void
12643 Target_arm<big_endian>::do_define_standard_symbols(
12644 Symbol_table* symtab,
12645 Layout* layout)
12646 {
12647 // Handle the .ARM.exidx section.
12648 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12649
12650 if (exidx_section != NULL)
12651 {
12652 // Create __exidx_start and __exidx_end symbols.
12653 symtab->define_in_output_data("__exidx_start",
12654 NULL, // version
12655 Symbol_table::PREDEFINED,
12656 exidx_section,
12657 0, // value
12658 0, // symsize
12659 elfcpp::STT_NOTYPE,
12660 elfcpp::STB_GLOBAL,
12661 elfcpp::STV_HIDDEN,
12662 0, // nonvis
12663 false, // offset_is_from_end
12664 true); // only_if_ref
12665
12666 symtab->define_in_output_data("__exidx_end",
12667 NULL, // version
12668 Symbol_table::PREDEFINED,
12669 exidx_section,
12670 0, // value
12671 0, // symsize
12672 elfcpp::STT_NOTYPE,
12673 elfcpp::STB_GLOBAL,
12674 elfcpp::STV_HIDDEN,
12675 0, // nonvis
12676 true, // offset_is_from_end
12677 true); // only_if_ref
12678 }
12679 else
12680 {
12681 // Define __exidx_start and __exidx_end even when .ARM.exidx
12682 // section is missing to match ld's behaviour.
12683 symtab->define_as_constant("__exidx_start", NULL,
12684 Symbol_table::PREDEFINED,
12685 0, 0, elfcpp::STT_OBJECT,
12686 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12687 true, false);
12688 symtab->define_as_constant("__exidx_end", NULL,
12689 Symbol_table::PREDEFINED,
12690 0, 0, elfcpp::STT_OBJECT,
12691 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12692 true, false);
12693 }
12694 }
12695
12696 // NaCl variant. It uses different PLT contents.
12697
12698 template<bool big_endian>
12699 class Output_data_plt_arm_nacl;
12700
12701 template<bool big_endian>
12702 class Target_arm_nacl : public Target_arm<big_endian>
12703 {
12704 public:
12705 Target_arm_nacl()
12706 : Target_arm<big_endian>(&arm_nacl_info)
12707 { }
12708
12709 protected:
12710 virtual Output_data_plt_arm<big_endian>*
12711 do_make_data_plt(
12712 Layout* layout,
12713 Arm_output_data_got<big_endian>* got,
12714 Output_data_space* got_plt,
12715 Output_data_space* got_irelative)
12716 { return new Output_data_plt_arm_nacl<big_endian>(
12717 layout, got, got_plt, got_irelative); }
12718
12719 private:
12720 static const Target::Target_info arm_nacl_info;
12721 };
12722
12723 template<bool big_endian>
12724 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12725 {
12726 32, // size
12727 big_endian, // is_big_endian
12728 elfcpp::EM_ARM, // machine_code
12729 false, // has_make_symbol
12730 false, // has_resolve
12731 false, // has_code_fill
12732 true, // is_default_stack_executable
12733 false, // can_icf_inline_merge_sections
12734 '\0', // wrap_char
12735 "/lib/ld-nacl-arm.so.1", // dynamic_linker
12736 0x20000, // default_text_segment_address
12737 0x10000, // abi_pagesize (overridable by -z max-page-size)
12738 0x10000, // common_pagesize (overridable by -z common-page-size)
12739 true, // isolate_execinstr
12740 0x10000000, // rosegment_gap
12741 elfcpp::SHN_UNDEF, // small_common_shndx
12742 elfcpp::SHN_UNDEF, // large_common_shndx
12743 0, // small_common_section_flags
12744 0, // large_common_section_flags
12745 ".ARM.attributes", // attributes_section
12746 "aeabi", // attributes_vendor
12747 "_start" // entry_symbol_name
12748 };
12749
12750 template<bool big_endian>
12751 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12752 {
12753 public:
12754 Output_data_plt_arm_nacl(
12755 Layout* layout,
12756 Arm_output_data_got<big_endian>* got,
12757 Output_data_space* got_plt,
12758 Output_data_space* got_irelative)
12759 : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
12760 { }
12761
12762 protected:
12763 // Return the offset of the first non-reserved PLT entry.
12764 virtual unsigned int
12765 do_first_plt_entry_offset() const
12766 { return sizeof(first_plt_entry); }
12767
12768 // Return the size of a PLT entry.
12769 virtual unsigned int
12770 do_get_plt_entry_size() const
12771 { return sizeof(plt_entry); }
12772
12773 virtual void
12774 do_fill_first_plt_entry(unsigned char* pov,
12775 Arm_address got_address,
12776 Arm_address plt_address);
12777
12778 virtual void
12779 do_fill_plt_entry(unsigned char* pov,
12780 Arm_address got_address,
12781 Arm_address plt_address,
12782 unsigned int got_offset,
12783 unsigned int plt_offset);
12784
12785 private:
12786 inline uint32_t arm_movw_immediate(uint32_t value)
12787 {
12788 return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12789 }
12790
12791 inline uint32_t arm_movt_immediate(uint32_t value)
12792 {
12793 return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12794 }
12795
12796 // Template for the first PLT entry.
12797 static const uint32_t first_plt_entry[16];
12798
12799 // Template for subsequent PLT entries.
12800 static const uint32_t plt_entry[4];
12801 };
12802
12803 // The first entry in the PLT.
12804 template<bool big_endian>
12805 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12806 {
12807 // First bundle:
12808 0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8
12809 0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8
12810 0xe08cc00f, // add ip, ip, pc
12811 0xe52dc008, // str ip, [sp, #-8]!
12812 // Second bundle:
12813 0xe3ccc103, // bic ip, ip, #0xc0000000
12814 0xe59cc000, // ldr ip, [ip]
12815 0xe3ccc13f, // bic ip, ip, #0xc000000f
12816 0xe12fff1c, // bx ip
12817 // Third bundle:
12818 0xe320f000, // nop
12819 0xe320f000, // nop
12820 0xe320f000, // nop
12821 // .Lplt_tail:
12822 0xe50dc004, // str ip, [sp, #-4]
12823 // Fourth bundle:
12824 0xe3ccc103, // bic ip, ip, #0xc0000000
12825 0xe59cc000, // ldr ip, [ip]
12826 0xe3ccc13f, // bic ip, ip, #0xc000000f
12827 0xe12fff1c, // bx ip
12828 };
12829
12830 template<bool big_endian>
12831 void
12832 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12833 unsigned char* pov,
12834 Arm_address got_address,
12835 Arm_address plt_address)
12836 {
12837 // Write first PLT entry. All but first two words are constants.
12838 const size_t num_first_plt_words = (sizeof(first_plt_entry)
12839 / sizeof(first_plt_entry[0]));
12840
12841 int32_t got_displacement = got_address + 8 - (plt_address + 16);
12842
12843 elfcpp::Swap<32, big_endian>::writeval
12844 (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12845 elfcpp::Swap<32, big_endian>::writeval
12846 (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12847
12848 for (size_t i = 2; i < num_first_plt_words; ++i)
12849 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12850 }
12851
12852 // Subsequent entries in the PLT.
12853
12854 template<bool big_endian>
12855 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12856 {
12857 0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8
12858 0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8
12859 0xe08cc00f, // add ip, ip, pc
12860 0xea000000, // b .Lplt_tail
12861 };
12862
12863 template<bool big_endian>
12864 void
12865 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12866 unsigned char* pov,
12867 Arm_address got_address,
12868 Arm_address plt_address,
12869 unsigned int got_offset,
12870 unsigned int plt_offset)
12871 {
12872 // Calculate the displacement between the PLT slot and the
12873 // common tail that's part of the special initial PLT slot.
12874 int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12875 - (plt_address + plt_offset
12876 + sizeof(plt_entry) + sizeof(uint32_t)));
12877 gold_assert((tail_displacement & 3) == 0);
12878 tail_displacement >>= 2;
12879
12880 gold_assert ((tail_displacement & 0xff000000) == 0
12881 || (-tail_displacement & 0xff000000) == 0);
12882
12883 // Calculate the displacement between the PLT slot and the entry
12884 // in the GOT. The offset accounts for the value produced by
12885 // adding to pc in the penultimate instruction of the PLT stub.
12886 const int32_t got_displacement = (got_address + got_offset
12887 - (plt_address + sizeof(plt_entry)));
12888
12889 elfcpp::Swap<32, big_endian>::writeval
12890 (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12891 elfcpp::Swap<32, big_endian>::writeval
12892 (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12893 elfcpp::Swap<32, big_endian>::writeval
12894 (pov + 8, plt_entry[2]);
12895 elfcpp::Swap<32, big_endian>::writeval
12896 (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12897 }
12898
12899 // Target selectors.
12900
12901 template<bool big_endian>
12902 class Target_selector_arm_nacl
12903 : public Target_selector_nacl<Target_selector_arm<big_endian>,
12904 Target_arm_nacl<big_endian> >
12905 {
12906 public:
12907 Target_selector_arm_nacl()
12908 : Target_selector_nacl<Target_selector_arm<big_endian>,
12909 Target_arm_nacl<big_endian> >(
12910 "arm",
12911 big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12912 big_endian ? "armelfb_nacl" : "armelf_nacl")
12913 { }
12914 };
12915
12916 Target_selector_arm_nacl<false> target_selector_arm;
12917 Target_selector_arm_nacl<true> target_selector_armbe;
12918
12919 } // End anonymous namespace.
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