1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
28 #include "parameters.h"
36 #include "target-reloc.h"
37 #include "target-select.h"
44 class Output_data_plt_i386
;
46 // The i386 target class.
48 class Target_i386
: public Sized_target
<32, false>
51 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
54 : Sized_target
<32, false>(&i386_info
),
55 got_(NULL
), plt_(NULL
), got_plt_(NULL
), rel_dyn_(NULL
),
56 copy_relocs_(NULL
), dynbss_(NULL
)
59 // Scan the relocations to look for symbol adjustments.
61 scan_relocs(const General_options
& options
,
64 Sized_relobj
<32, false>* object
,
65 unsigned int data_shndx
,
67 const unsigned char* prelocs
,
69 size_t local_symbol_count
,
70 const unsigned char* plocal_symbols
,
71 Symbol
** global_symbols
);
73 // Finalize the sections.
75 do_finalize_sections(Layout
*);
77 // Return the value to use for a dynamic which requires special
80 do_dynsym_value(const Symbol
*) const;
82 // Relocate a section.
84 relocate_section(const Relocate_info
<32, false>*,
86 const unsigned char* prelocs
,
89 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
92 // Return a string used to fill a code section with nops.
94 do_code_fill(off_t length
);
97 // The class which scans relocations.
101 local(const General_options
& options
, Symbol_table
* symtab
,
102 Layout
* layout
, Target_i386
* target
,
103 Sized_relobj
<32, false>* object
,
104 unsigned int data_shndx
,
105 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
106 const elfcpp::Sym
<32, false>& lsym
);
109 global(const General_options
& options
, Symbol_table
* symtab
,
110 Layout
* layout
, Target_i386
* target
,
111 Sized_relobj
<32, false>* object
,
112 unsigned int data_shndx
,
113 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
117 // The class which implements relocation.
122 : skip_call_tls_get_addr_(false),
123 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
128 if (this->skip_call_tls_get_addr_
)
130 // FIXME: This needs to specify the location somehow.
131 fprintf(stderr
, _("%s: missing expected TLS relocation\n"),
137 // Do a relocation. Return false if the caller should not issue
138 // any warnings about this relocation.
140 relocate(const Relocate_info
<32, false>*, Target_i386
*, size_t relnum
,
141 const elfcpp::Rel
<32, false>&,
142 unsigned int r_type
, const Sized_symbol
<32>*,
143 const Symbol_value
<32>*,
144 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
148 // Do a TLS relocation.
150 relocate_tls(const Relocate_info
<32, false>*, size_t relnum
,
151 const elfcpp::Rel
<32, false>&,
152 unsigned int r_type
, const Sized_symbol
<32>*,
153 const Symbol_value
<32>*,
154 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
, off_t
);
156 // Do a TLS Initial-Exec to Local-Exec transition.
158 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
159 Output_segment
* tls_segment
,
160 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
161 elfcpp::Elf_types
<32>::Elf_Addr value
,
165 // Do a TLS Global-Dynamic to Local-Exec transition.
167 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
168 Output_segment
* tls_segment
,
169 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
170 elfcpp::Elf_types
<32>::Elf_Addr value
,
174 // Do a TLS Local-Dynamic to Local-Exec transition.
176 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
177 Output_segment
* tls_segment
,
178 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
179 elfcpp::Elf_types
<32>::Elf_Addr value
,
183 // Check the range for a TLS relocation.
185 check_range(const Relocate_info
<32, false>*, size_t relnum
,
186 const elfcpp::Rel
<32, false>&, off_t
, off_t
);
188 // Check the validity of a TLS relocation. This is like assert.
190 check_tls(const Relocate_info
<32, false>*, size_t relnum
,
191 const elfcpp::Rel
<32, false>&, bool);
193 // We need to keep track of which type of local dynamic relocation
194 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
195 enum Local_dynamic_type
202 // This is set if we should skip the next reloc, which should be a
203 // PLT32 reloc against ___tls_get_addr.
204 bool skip_call_tls_get_addr_
;
205 // The type of local dynamic relocation we have seen in the section
206 // being relocated, if any.
207 Local_dynamic_type local_dynamic_type_
;
210 // Adjust TLS relocation type based on the options and whether this
211 // is a local symbol.
213 optimize_tls_reloc(bool is_final
, int r_type
);
215 // Get the GOT section, creating it if necessary.
216 Output_data_got
<32, false>*
217 got_section(Symbol_table
*, Layout
*);
219 // Create a PLT entry for a global symbol.
221 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
223 // Get the PLT section.
224 const Output_data_plt_i386
*
227 gold_assert(this->plt_
!= NULL
);
231 // Get the dynamic reloc section, creating it if necessary.
233 rel_dyn_section(Layout
*);
235 // Copy a relocation against a global symbol.
237 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
238 Sized_relobj
<32, false>*, unsigned int,
239 Symbol
*, const elfcpp::Rel
<32, false>&);
241 // Information about this specific target which we pass to the
242 // general Target structure.
243 static const Target::Target_info i386_info
;
246 Output_data_got
<32, false>* got_
;
248 Output_data_plt_i386
* plt_
;
249 // The GOT PLT section.
250 Output_data_space
* got_plt_
;
251 // The dynamic reloc section.
252 Reloc_section
* rel_dyn_
;
253 // Relocs saved to avoid a COPY reloc.
254 Copy_relocs
<32, false>* copy_relocs_
;
255 // Space for variables copied with a COPY reloc.
256 Output_data_space
* dynbss_
;
259 const Target::Target_info
Target_i386::i386_info
=
262 false, // is_big_endian
263 elfcpp::EM_386
, // machine_code
264 false, // has_make_symbol
265 false, // has_resolve
266 true, // has_code_fill
267 "/usr/lib/libc.so.1", // dynamic_linker
268 0x08048000, // text_segment_address
269 0x1000, // abi_pagesize
270 0x1000 // common_pagesize
273 // Get the GOT section, creating it if necessary.
275 Output_data_got
<32, false>*
276 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
278 if (this->got_
== NULL
)
280 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
282 this->got_
= new Output_data_got
<32, false>();
284 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
285 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
288 // The old GNU linker creates a .got.plt section. We just
289 // create another set of data in the .got section. Note that we
290 // always create a PLT if we create a GOT, although the PLT
292 this->got_plt_
= new Output_data_space(4);
293 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
294 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
297 // The first three entries are reserved.
298 this->got_plt_
->set_space_size(3 * 4);
300 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
301 symtab
->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL
,
303 0, 0, elfcpp::STT_OBJECT
,
305 elfcpp::STV_HIDDEN
, 0,
312 // Get the dynamic reloc section, creating it if necessary.
314 Target_i386::Reloc_section
*
315 Target_i386::rel_dyn_section(Layout
* layout
)
317 if (this->rel_dyn_
== NULL
)
319 gold_assert(layout
!= NULL
);
320 this->rel_dyn_
= new Reloc_section();
321 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
322 elfcpp::SHF_ALLOC
, this->rel_dyn_
);
324 return this->rel_dyn_
;
327 // A class to handle the PLT data.
329 class Output_data_plt_i386
: public Output_section_data
332 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
334 Output_data_plt_i386(Layout
*, Output_data_space
*);
336 // Add an entry to the PLT.
338 add_entry(Symbol
* gsym
);
340 // Return the .rel.plt section data.
343 { return this->rel_
; }
347 do_adjust_output_section(Output_section
* os
);
350 // The size of an entry in the PLT.
351 static const int plt_entry_size
= 16;
353 // The first entry in the PLT for an executable.
354 static unsigned char exec_first_plt_entry
[plt_entry_size
];
356 // The first entry in the PLT for a shared object.
357 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
359 // Other entries in the PLT for an executable.
360 static unsigned char exec_plt_entry
[plt_entry_size
];
362 // Other entries in the PLT for a shared object.
363 static unsigned char dyn_plt_entry
[plt_entry_size
];
365 // Set the final size.
367 do_set_address(uint64_t, off_t
)
368 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
370 // Write out the PLT data.
372 do_write(Output_file
*);
374 // The reloc section.
376 // The .got.plt section.
377 Output_data_space
* got_plt_
;
378 // The number of PLT entries.
382 // Create the PLT section. The ordinary .got section is an argument,
383 // since we need to refer to the start. We also create our own .got
384 // section just for PLT entries.
386 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
387 Output_data_space
* got_plt
)
388 : Output_section_data(4), got_plt_(got_plt
), count_(0)
390 this->rel_
= new Reloc_section();
391 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
392 elfcpp::SHF_ALLOC
, this->rel_
);
396 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
398 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
399 // linker, and so do we.
403 // Add an entry to the PLT.
406 Output_data_plt_i386::add_entry(Symbol
* gsym
)
408 gold_assert(!gsym
->has_plt_offset());
410 // Note that when setting the PLT offset we skip the initial
411 // reserved PLT entry.
412 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
416 off_t got_offset
= this->got_plt_
->data_size();
418 // Every PLT entry needs a GOT entry which points back to the PLT
419 // entry (this will be changed by the dynamic linker, normally
420 // lazily when the function is called).
421 this->got_plt_
->set_space_size(got_offset
+ 4);
423 // Every PLT entry needs a reloc.
424 gsym
->set_needs_dynsym_entry();
425 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
428 // Note that we don't need to save the symbol. The contents of the
429 // PLT are independent of which symbols are used. The symbols only
430 // appear in the relocations.
433 // The first entry in the PLT for an executable.
435 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
437 0xff, 0x35, // pushl contents of memory address
438 0, 0, 0, 0, // replaced with address of .got + 4
439 0xff, 0x25, // jmp indirect
440 0, 0, 0, 0, // replaced with address of .got + 8
444 // The first entry in the PLT for a shared object.
446 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
448 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
449 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
453 // Subsequent entries in the PLT for an executable.
455 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
457 0xff, 0x25, // jmp indirect
458 0, 0, 0, 0, // replaced with address of symbol in .got
459 0x68, // pushl immediate
460 0, 0, 0, 0, // replaced with offset into relocation table
461 0xe9, // jmp relative
462 0, 0, 0, 0 // replaced with offset to start of .plt
465 // Subsequent entries in the PLT for a shared object.
467 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
469 0xff, 0xa3, // jmp *offset(%ebx)
470 0, 0, 0, 0, // replaced with offset of symbol in .got
471 0x68, // pushl immediate
472 0, 0, 0, 0, // replaced with offset into relocation table
473 0xe9, // jmp relative
474 0, 0, 0, 0 // replaced with offset to start of .plt
477 // Write out the PLT. This uses the hand-coded instructions above,
478 // and adjusts them as needed. This is all specified by the i386 ELF
479 // Processor Supplement.
482 Output_data_plt_i386::do_write(Output_file
* of
)
484 const off_t offset
= this->offset();
485 const off_t oview_size
= this->data_size();
486 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
488 const off_t got_file_offset
= this->got_plt_
->offset();
489 const off_t got_size
= this->got_plt_
->data_size();
490 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
493 unsigned char* pov
= oview
;
495 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
496 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
498 if (parameters
->output_is_shared())
499 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
502 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
503 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
504 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
506 pov
+= plt_entry_size
;
508 unsigned char* got_pov
= got_view
;
510 memset(got_pov
, 0, 12);
513 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
515 unsigned int plt_offset
= plt_entry_size
;
516 unsigned int plt_rel_offset
= 0;
517 unsigned int got_offset
= 12;
518 const unsigned int count
= this->count_
;
519 for (unsigned int i
= 0;
522 pov
+= plt_entry_size
,
524 plt_offset
+= plt_entry_size
,
525 plt_rel_offset
+= rel_size
,
528 // Set and adjust the PLT entry itself.
530 if (parameters
->output_is_shared())
532 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
533 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
537 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
538 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
543 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
544 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
545 - (plt_offset
+ plt_entry_size
));
547 // Set the entry in the GOT.
548 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
551 gold_assert(pov
- oview
== oview_size
);
552 gold_assert(got_pov
- got_view
== got_size
);
554 of
->write_output_view(offset
, oview_size
, oview
);
555 of
->write_output_view(got_file_offset
, got_size
, got_view
);
558 // Create a PLT entry for a global symbol.
561 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
563 if (gsym
->has_plt_offset())
566 if (this->plt_
== NULL
)
568 // Create the GOT sections first.
569 this->got_section(symtab
, layout
);
571 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
572 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
574 | elfcpp::SHF_EXECINSTR
),
578 this->plt_
->add_entry(gsym
);
581 // Handle a relocation against a non-function symbol defined in a
582 // dynamic object. The traditional way to handle this is to generate
583 // a COPY relocation to copy the variable at runtime from the shared
584 // object into the executable's data segment. However, this is
585 // undesirable in general, as if the size of the object changes in the
586 // dynamic object, the executable will no longer work correctly. If
587 // this relocation is in a writable section, then we can create a
588 // dynamic reloc and the dynamic linker will resolve it to the correct
589 // address at runtime. However, we do not want do that if the
590 // relocation is in a read-only section, as it would prevent the
591 // readonly segment from being shared. And if we have to eventually
592 // generate a COPY reloc, then any dynamic relocations will be
593 // useless. So this means that if this is a writable section, we need
594 // to save the relocation until we see whether we have to create a
595 // COPY relocation for this symbol for any other relocation.
598 Target_i386::copy_reloc(const General_options
* options
,
599 Symbol_table
* symtab
,
601 Sized_relobj
<32, false>* object
,
602 unsigned int data_shndx
, Symbol
* gsym
,
603 const elfcpp::Rel
<32, false>& rel
)
605 Sized_symbol
<32>* ssym
;
606 ssym
= symtab
->get_sized_symbol
SELECT_SIZE_NAME(32) (gsym
609 if (!Copy_relocs
<32, false>::need_copy_reloc(options
, object
,
612 // So far we do not need a COPY reloc. Save this relocation.
613 // If it turns out that we never need a COPY reloc for this
614 // symbol, then we will emit the relocation.
615 if (this->copy_relocs_
== NULL
)
616 this->copy_relocs_
= new Copy_relocs
<32, false>();
617 this->copy_relocs_
->save(ssym
, object
, data_shndx
, rel
);
621 // Allocate space for this symbol in the .bss section.
623 elfcpp::Elf_types
<32>::Elf_WXword symsize
= ssym
->symsize();
625 // There is no defined way to determine the required alignment
626 // of the symbol. We pick the alignment based on the size. We
627 // set an arbitrary maximum of 256.
629 for (align
= 1; align
< 512; align
<<= 1)
630 if ((symsize
& align
) != 0)
633 if (this->dynbss_
== NULL
)
635 this->dynbss_
= new Output_data_space(align
);
636 layout
->add_output_section_data(".bss",
639 | elfcpp::SHF_WRITE
),
643 Output_data_space
* dynbss
= this->dynbss_
;
645 if (align
> dynbss
->addralign())
646 dynbss
->set_space_alignment(align
);
648 off_t dynbss_size
= dynbss
->data_size();
649 dynbss_size
= align_address(dynbss_size
, align
);
650 off_t offset
= dynbss_size
;
651 dynbss
->set_space_size(dynbss_size
+ symsize
);
653 // Define the symbol in the .dynbss section.
654 symtab
->define_in_output_data(this, ssym
->name(), ssym
->version(),
655 dynbss
, offset
, symsize
, ssym
->type(),
656 ssym
->binding(), ssym
->visibility(),
657 ssym
->nonvis(), false, false);
659 // Add the COPY reloc.
660 ssym
->set_needs_dynsym_entry();
661 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
662 rel_dyn
->add_global(ssym
, elfcpp::R_386_COPY
, dynbss
, offset
);
666 // Optimize the TLS relocation type based on what we know about the
667 // symbol. IS_FINAL is true if the final address of this symbol is
668 // known at link time.
671 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
673 // If we are generating a shared library, then we can't do anything
675 if (parameters
->output_is_shared())
680 case elfcpp::R_386_TLS_GD
:
681 case elfcpp::R_386_TLS_GOTDESC
:
682 case elfcpp::R_386_TLS_DESC_CALL
:
683 // These are Global-Dynamic which permits fully general TLS
684 // access. Since we know that we are generating an executable,
685 // we can convert this to Initial-Exec. If we also know that
686 // this is a local symbol, we can further switch to Local-Exec.
688 return elfcpp::R_386_TLS_LE_32
;
689 return elfcpp::R_386_TLS_IE_32
;
691 case elfcpp::R_386_TLS_LDM
:
692 // This is Local-Dynamic, which refers to a local symbol in the
693 // dynamic TLS block. Since we know that we generating an
694 // executable, we can switch to Local-Exec.
695 return elfcpp::R_386_TLS_LE_32
;
697 case elfcpp::R_386_TLS_LDO_32
:
698 // Another type of Local-Dynamic relocation. We return a
699 // different value as we need to negate the thread segment
700 // offset. FIXME: Returning reloc types makes no sense.
701 return elfcpp::R_386_TLS_LE
;
703 case elfcpp::R_386_TLS_IE
:
704 case elfcpp::R_386_TLS_GOTIE
:
705 case elfcpp::R_386_TLS_IE_32
:
706 // These are Initial-Exec relocs which get the thread offset
707 // from the GOT. If we know that we are linking against the
708 // local symbol, we can switch to Local-Exec, which links the
709 // thread offset into the instruction.
711 return elfcpp::R_386_TLS_LE_32
;
714 case elfcpp::R_386_TLS_LE
:
715 case elfcpp::R_386_TLS_LE_32
:
716 // When we already have Local-Exec, there is nothing further we
725 // Scan a relocation for a local symbol.
728 Target_i386::Scan::local(const General_options
&,
729 Symbol_table
* symtab
,
732 Sized_relobj
<32, false>* object
,
734 const elfcpp::Rel
<32, false>&,
736 const elfcpp::Sym
<32, false>&)
740 case elfcpp::R_386_NONE
:
741 case elfcpp::R_386_GNU_VTINHERIT
:
742 case elfcpp::R_386_GNU_VTENTRY
:
745 case elfcpp::R_386_32
:
746 case elfcpp::R_386_16
:
747 case elfcpp::R_386_8
:
748 // FIXME: If we are generating a shared object we need to copy
749 // this relocation into the object.
750 gold_assert(!parameters
->output_is_shared());
753 case elfcpp::R_386_PC32
:
754 case elfcpp::R_386_PC16
:
755 case elfcpp::R_386_PC8
:
758 case elfcpp::R_386_GOTOFF
:
759 case elfcpp::R_386_GOTPC
:
760 // We need a GOT section.
761 target
->got_section(symtab
, layout
);
764 case elfcpp::R_386_COPY
:
765 case elfcpp::R_386_GLOB_DAT
:
766 case elfcpp::R_386_JUMP_SLOT
:
767 case elfcpp::R_386_RELATIVE
:
768 // These are outstanding tls relocs, which are unexpected when
770 case elfcpp::R_386_TLS_TPOFF
:
771 case elfcpp::R_386_TLS_DTPMOD32
:
772 case elfcpp::R_386_TLS_DTPOFF32
:
773 case elfcpp::R_386_TLS_TPOFF32
:
774 case elfcpp::R_386_TLS_DESC
:
775 fprintf(stderr
, _("%s: %s: unexpected reloc %u in object file\n"),
776 program_name
, object
->name().c_str(), r_type
);
780 // These are initial tls relocs, which are expected when
782 case elfcpp::R_386_TLS_IE
:
783 case elfcpp::R_386_TLS_GOTIE
:
784 case elfcpp::R_386_TLS_LE
:
785 case elfcpp::R_386_TLS_GD
:
786 case elfcpp::R_386_TLS_LDM
:
787 case elfcpp::R_386_TLS_LDO_32
:
788 case elfcpp::R_386_TLS_IE_32
:
789 case elfcpp::R_386_TLS_LE_32
:
790 case elfcpp::R_386_TLS_GOTDESC
:
791 case elfcpp::R_386_TLS_DESC_CALL
:
793 bool output_is_shared
= parameters
->output_is_shared();
794 r_type
= Target_i386::optimize_tls_reloc(!output_is_shared
,
798 case elfcpp::R_386_TLS_LE
:
799 case elfcpp::R_386_TLS_LE_32
:
800 // FIXME: If generating a shared object, we need to copy
801 // this relocation into the object.
802 gold_assert(!output_is_shared
);
805 case elfcpp::R_386_TLS_LDM
:
806 case elfcpp::R_386_TLS_LDO_32
:
809 case elfcpp::R_386_TLS_IE
:
810 case elfcpp::R_386_TLS_GOTIE
:
811 case elfcpp::R_386_TLS_GD
:
812 case elfcpp::R_386_TLS_IE_32
:
813 case elfcpp::R_386_TLS_GOTDESC
:
814 case elfcpp::R_386_TLS_DESC_CALL
:
816 _("%s: %s: unsupported reloc %u against local symbol\n"),
817 program_name
, object
->name().c_str(), r_type
);
823 case elfcpp::R_386_GOT32
:
824 case elfcpp::R_386_PLT32
:
825 case elfcpp::R_386_32PLT
:
826 case elfcpp::R_386_TLS_GD_32
:
827 case elfcpp::R_386_TLS_GD_PUSH
:
828 case elfcpp::R_386_TLS_GD_CALL
:
829 case elfcpp::R_386_TLS_GD_POP
:
830 case elfcpp::R_386_TLS_LDM_32
:
831 case elfcpp::R_386_TLS_LDM_PUSH
:
832 case elfcpp::R_386_TLS_LDM_CALL
:
833 case elfcpp::R_386_TLS_LDM_POP
:
834 case elfcpp::R_386_USED_BY_INTEL_200
:
836 fprintf(stderr
, _("%s: %s: unsupported reloc %u against local symbol\n"),
837 program_name
, object
->name().c_str(), r_type
);
842 // Scan a relocation for a global symbol.
845 Target_i386::Scan::global(const General_options
& options
,
846 Symbol_table
* symtab
,
849 Sized_relobj
<32, false>* object
,
850 unsigned int data_shndx
,
851 const elfcpp::Rel
<32, false>& reloc
,
857 case elfcpp::R_386_NONE
:
858 case elfcpp::R_386_GNU_VTINHERIT
:
859 case elfcpp::R_386_GNU_VTENTRY
:
862 case elfcpp::R_386_32
:
863 case elfcpp::R_386_PC32
:
864 case elfcpp::R_386_16
:
865 case elfcpp::R_386_PC16
:
866 case elfcpp::R_386_8
:
867 case elfcpp::R_386_PC8
:
868 // FIXME: If we are generating a shared object we may need to
869 // copy this relocation into the object. If this symbol is
870 // defined in a shared object, we may need to copy this
871 // relocation in order to avoid a COPY relocation.
872 gold_assert(!parameters
->output_is_shared());
874 if (gsym
->is_from_dynobj())
876 // This symbol is defined in a dynamic object. If it is a
877 // function, we make a PLT entry. Otherwise we need to
878 // either generate a COPY reloc or copy this reloc.
879 if (gsym
->type() == elfcpp::STT_FUNC
)
881 target
->make_plt_entry(symtab
, layout
, gsym
);
883 // If this is not a PC relative reference, then we may
884 // be taking the address of the function. In that case
885 // we need to set the entry in the dynamic symbol table
886 // to the address of the PLT entry.
887 if (r_type
!= elfcpp::R_386_PC32
888 && r_type
!= elfcpp::R_386_PC16
889 && r_type
!= elfcpp::R_386_PC8
)
890 gsym
->set_needs_dynsym_value();
893 target
->copy_reloc(&options
, symtab
, layout
, object
, data_shndx
,
899 case elfcpp::R_386_GOT32
:
901 // The symbol requires a GOT entry.
902 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
903 if (got
->add_global(gsym
))
905 // If this symbol is not fully resolved, we need to add a
906 // dynamic relocation for it.
907 if (!gsym
->final_value_is_known())
909 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
910 rel_dyn
->add_global(gsym
, elfcpp::R_386_GLOB_DAT
, got
,
917 case elfcpp::R_386_PLT32
:
918 // If the symbol is fully resolved, this is just a PC32 reloc.
919 // Otherwise we need a PLT entry.
920 if (gsym
->final_value_is_known())
922 target
->make_plt_entry(symtab
, layout
, gsym
);
925 case elfcpp::R_386_GOTOFF
:
926 case elfcpp::R_386_GOTPC
:
927 // We need a GOT section.
928 target
->got_section(symtab
, layout
);
931 case elfcpp::R_386_COPY
:
932 case elfcpp::R_386_GLOB_DAT
:
933 case elfcpp::R_386_JUMP_SLOT
:
934 case elfcpp::R_386_RELATIVE
:
935 // These are outstanding tls relocs, which are unexpected when
937 case elfcpp::R_386_TLS_TPOFF
:
938 case elfcpp::R_386_TLS_DTPMOD32
:
939 case elfcpp::R_386_TLS_DTPOFF32
:
940 case elfcpp::R_386_TLS_TPOFF32
:
941 case elfcpp::R_386_TLS_DESC
:
942 fprintf(stderr
, _("%s: %s: unexpected reloc %u in object file\n"),
943 program_name
, object
->name().c_str(), r_type
);
947 // These are initial tls relocs, which are expected when
949 case elfcpp::R_386_TLS_IE
:
950 case elfcpp::R_386_TLS_GOTIE
:
951 case elfcpp::R_386_TLS_LE
:
952 case elfcpp::R_386_TLS_GD
:
953 case elfcpp::R_386_TLS_LDM
:
954 case elfcpp::R_386_TLS_LDO_32
:
955 case elfcpp::R_386_TLS_IE_32
:
956 case elfcpp::R_386_TLS_LE_32
:
957 case elfcpp::R_386_TLS_GOTDESC
:
958 case elfcpp::R_386_TLS_DESC_CALL
:
960 const bool is_final
= gsym
->final_value_is_known();
961 r_type
= Target_i386::optimize_tls_reloc(is_final
, r_type
);
964 case elfcpp::R_386_TLS_LE
:
965 case elfcpp::R_386_TLS_LE_32
:
966 // FIXME: If generating a shared object, we need to copy
967 // this relocation into the object.
968 gold_assert(!parameters
->output_is_shared());
971 case elfcpp::R_386_TLS_LDM
:
972 case elfcpp::R_386_TLS_LDO_32
:
975 case elfcpp::R_386_TLS_IE
:
976 case elfcpp::R_386_TLS_GOTIE
:
977 case elfcpp::R_386_TLS_GD
:
978 case elfcpp::R_386_TLS_IE_32
:
979 case elfcpp::R_386_TLS_GOTDESC
:
980 case elfcpp::R_386_TLS_DESC_CALL
:
982 _("%s: %s: unsupported reloc %u "
983 "against global symbol %s\n"),
984 program_name
, object
->name().c_str(), r_type
,
991 case elfcpp::R_386_32PLT
:
992 case elfcpp::R_386_TLS_GD_32
:
993 case elfcpp::R_386_TLS_GD_PUSH
:
994 case elfcpp::R_386_TLS_GD_CALL
:
995 case elfcpp::R_386_TLS_GD_POP
:
996 case elfcpp::R_386_TLS_LDM_32
:
997 case elfcpp::R_386_TLS_LDM_PUSH
:
998 case elfcpp::R_386_TLS_LDM_CALL
:
999 case elfcpp::R_386_TLS_LDM_POP
:
1000 case elfcpp::R_386_USED_BY_INTEL_200
:
1003 _("%s: %s: unsupported reloc %u against global symbol %s\n"),
1004 program_name
, object
->name().c_str(), r_type
, gsym
->name());
1009 // Scan relocations for a section.
1012 Target_i386::scan_relocs(const General_options
& options
,
1013 Symbol_table
* symtab
,
1015 Sized_relobj
<32, false>* object
,
1016 unsigned int data_shndx
,
1017 unsigned int sh_type
,
1018 const unsigned char* prelocs
,
1020 size_t local_symbol_count
,
1021 const unsigned char* plocal_symbols
,
1022 Symbol
** global_symbols
)
1024 if (sh_type
== elfcpp::SHT_RELA
)
1026 fprintf(stderr
, _("%s: %s: unsupported RELA reloc section\n"),
1027 program_name
, object
->name().c_str());
1031 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1046 // Finalize the sections.
1049 Target_i386::do_finalize_sections(Layout
* layout
)
1051 // Fill in some more dynamic tags.
1052 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1055 if (this->got_plt_
!= NULL
)
1056 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1058 if (this->plt_
!= NULL
)
1060 const Output_data
* od
= this->plt_
->rel_plt();
1061 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1062 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1063 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
1066 if (this->rel_dyn_
!= NULL
)
1068 const Output_data
* od
= this->rel_dyn_
;
1069 odyn
->add_section_address(elfcpp::DT_REL
, od
);
1070 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
1071 odyn
->add_constant(elfcpp::DT_RELENT
,
1072 elfcpp::Elf_sizes
<32>::rel_size
);
1075 if (!parameters
->output_is_shared())
1077 // The value of the DT_DEBUG tag is filled in by the dynamic
1078 // linker at run time, and used by the debugger.
1079 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1083 // Emit any relocs we saved in an attempt to avoid generating COPY
1085 if (this->copy_relocs_
== NULL
)
1087 if (this->copy_relocs_
->any_to_emit())
1089 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1090 this->copy_relocs_
->emit(rel_dyn
);
1092 delete this->copy_relocs_
;
1093 this->copy_relocs_
= NULL
;
1096 // Perform a relocation.
1099 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1100 Target_i386
* target
,
1102 const elfcpp::Rel
<32, false>& rel
,
1103 unsigned int r_type
,
1104 const Sized_symbol
<32>* gsym
,
1105 const Symbol_value
<32>* psymval
,
1106 unsigned char* view
,
1107 elfcpp::Elf_types
<32>::Elf_Addr address
,
1110 if (this->skip_call_tls_get_addr_
)
1112 if (r_type
!= elfcpp::R_386_PLT32
1114 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1116 fprintf(stderr
, _("%s: %s: missing expected TLS relocation\n"),
1118 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1122 this->skip_call_tls_get_addr_
= false;
1127 // Pick the value to use for symbols defined in shared objects.
1128 Symbol_value
<32> symval
;
1129 if (gsym
!= NULL
&& gsym
->is_from_dynobj() && gsym
->has_plt_offset())
1131 symval
.set_output_value(target
->plt_section()->address()
1132 + gsym
->plt_offset());
1136 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1140 case elfcpp::R_386_NONE
:
1141 case elfcpp::R_386_GNU_VTINHERIT
:
1142 case elfcpp::R_386_GNU_VTENTRY
:
1145 case elfcpp::R_386_32
:
1146 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1149 case elfcpp::R_386_PC32
:
1150 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1153 case elfcpp::R_386_16
:
1154 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1157 case elfcpp::R_386_PC16
:
1158 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1161 case elfcpp::R_386_8
:
1162 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1165 case elfcpp::R_386_PC8
:
1166 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1169 case elfcpp::R_386_PLT32
:
1170 gold_assert(gsym
->has_plt_offset()
1171 || gsym
->final_value_is_known());
1172 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1175 case elfcpp::R_386_GOT32
:
1176 // Local GOT offsets not yet supported.
1178 gold_assert(gsym
->has_got_offset());
1179 Relocate_functions
<32, false>::rel32(view
, gsym
->got_offset());
1182 case elfcpp::R_386_GOTOFF
:
1184 elfcpp::Elf_types
<32>::Elf_Addr value
;
1185 value
= (psymval
->value(object
, 0)
1186 - target
->got_section(NULL
, NULL
)->address());
1187 Relocate_functions
<32, false>::rel32(view
, value
);
1191 case elfcpp::R_386_GOTPC
:
1193 elfcpp::Elf_types
<32>::Elf_Addr value
;
1194 value
= target
->got_section(NULL
, NULL
)->address();
1195 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1199 case elfcpp::R_386_COPY
:
1200 case elfcpp::R_386_GLOB_DAT
:
1201 case elfcpp::R_386_JUMP_SLOT
:
1202 case elfcpp::R_386_RELATIVE
:
1203 // These are outstanding tls relocs, which are unexpected when
1205 case elfcpp::R_386_TLS_TPOFF
:
1206 case elfcpp::R_386_TLS_DTPMOD32
:
1207 case elfcpp::R_386_TLS_DTPOFF32
:
1208 case elfcpp::R_386_TLS_TPOFF32
:
1209 case elfcpp::R_386_TLS_DESC
:
1210 fprintf(stderr
, _("%s: %s: unexpected reloc %u in object file\n"),
1212 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1217 // These are initial tls relocs, which are expected when
1219 case elfcpp::R_386_TLS_IE
:
1220 case elfcpp::R_386_TLS_GOTIE
:
1221 case elfcpp::R_386_TLS_LE
:
1222 case elfcpp::R_386_TLS_GD
:
1223 case elfcpp::R_386_TLS_LDM
:
1224 case elfcpp::R_386_TLS_LDO_32
:
1225 case elfcpp::R_386_TLS_IE_32
:
1226 case elfcpp::R_386_TLS_LE_32
:
1227 case elfcpp::R_386_TLS_GOTDESC
:
1228 case elfcpp::R_386_TLS_DESC_CALL
:
1229 this->relocate_tls(relinfo
, relnum
, rel
, r_type
, gsym
, psymval
, view
,
1230 address
, view_size
);
1233 case elfcpp::R_386_32PLT
:
1234 case elfcpp::R_386_TLS_GD_32
:
1235 case elfcpp::R_386_TLS_GD_PUSH
:
1236 case elfcpp::R_386_TLS_GD_CALL
:
1237 case elfcpp::R_386_TLS_GD_POP
:
1238 case elfcpp::R_386_TLS_LDM_32
:
1239 case elfcpp::R_386_TLS_LDM_PUSH
:
1240 case elfcpp::R_386_TLS_LDM_CALL
:
1241 case elfcpp::R_386_TLS_LDM_POP
:
1242 case elfcpp::R_386_USED_BY_INTEL_200
:
1244 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1246 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1248 // gold_exit(false);
1255 // Perform a TLS relocation.
1258 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1260 const elfcpp::Rel
<32, false>& rel
,
1261 unsigned int r_type
,
1262 const Sized_symbol
<32>* gsym
,
1263 const Symbol_value
<32>* psymval
,
1264 unsigned char* view
,
1265 elfcpp::Elf_types
<32>::Elf_Addr
,
1268 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1269 if (tls_segment
== NULL
)
1271 fprintf(stderr
, _("%s: %s: TLS reloc but no TLS segment\n"),
1273 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1277 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1279 const bool is_final
= (gsym
== NULL
1280 ? !parameters
->output_is_shared()
1281 : gsym
->final_value_is_known());
1282 const unsigned int opt_r_type
=
1283 Target_i386::optimize_tls_reloc(is_final
, r_type
);
1286 case elfcpp::R_386_TLS_LE_32
:
1287 value
= tls_segment
->vaddr() + tls_segment
->memsz() - value
;
1288 Relocate_functions
<32, false>::rel32(view
, value
);
1291 case elfcpp::R_386_TLS_LE
:
1292 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1293 Relocate_functions
<32, false>::rel32(view
, value
);
1296 case elfcpp::R_386_TLS_IE
:
1297 case elfcpp::R_386_TLS_GOTIE
:
1298 case elfcpp::R_386_TLS_IE_32
:
1299 if (opt_r_type
== elfcpp::R_386_TLS_LE_32
)
1301 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1302 rel
, r_type
, value
, view
,
1306 fprintf(stderr
, _("%s: %s: unsupported reloc type %u\n"),
1308 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1310 // gold_exit(false);
1313 case elfcpp::R_386_TLS_GD
:
1314 if (opt_r_type
== elfcpp::R_386_TLS_LE_32
)
1316 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1317 rel
, r_type
, value
, view
,
1321 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1323 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1325 // gold_exit(false);
1328 case elfcpp::R_386_TLS_LDM
:
1329 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
1332 _("%s: %s: both SUN and GNU model TLS relocations\n"),
1334 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1337 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1338 if (opt_r_type
== elfcpp::R_386_TLS_LE_32
)
1340 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1341 value
, view
, view_size
);
1344 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1346 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1348 // gold_exit(false);
1351 case elfcpp::R_386_TLS_LDO_32
:
1352 // This reloc can appear in debugging sections, in which case we
1353 // won't see the TLS_LDM reloc. The local_dynamic_type field
1355 if (opt_r_type
== elfcpp::R_386_TLS_LDO_32
1356 || this->local_dynamic_type_
== LOCAL_DYNAMIC_NONE
)
1357 value
= value
- tls_segment
->vaddr();
1358 else if (this->local_dynamic_type_
== LOCAL_DYNAMIC_GNU
)
1359 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1361 value
= tls_segment
->vaddr() + tls_segment
->memsz() - value
;
1362 Relocate_functions
<32, false>::rel32(view
, value
);
1365 case elfcpp::R_386_TLS_GOTDESC
:
1366 case elfcpp::R_386_TLS_DESC_CALL
:
1367 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1369 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1371 // gold_exit(false);
1376 // Do a relocation in which we convert a TLS Initial-Exec to a
1380 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
1382 Output_segment
* tls_segment
,
1383 const elfcpp::Rel
<32, false>& rel
,
1384 unsigned int r_type
,
1385 elfcpp::Elf_types
<32>::Elf_Addr value
,
1386 unsigned char* view
,
1389 // We have to actually change the instructions, which means that we
1390 // need to examine the opcodes to figure out which instruction we
1392 if (r_type
== elfcpp::R_386_TLS_IE
)
1394 // movl %gs:XX,%eax ==> movl $YY,%eax
1395 // movl %gs:XX,%reg ==> movl $YY,%reg
1396 // addl %gs:XX,%reg ==> addl $YY,%reg
1397 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -1);
1398 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 4);
1400 unsigned char op1
= view
[-1];
1403 // movl XX,%eax ==> movl $YY,%eax
1408 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
,
1411 unsigned char op2
= view
[-2];
1414 // movl XX,%reg ==> movl $YY,%reg
1415 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1416 (op1
& 0xc7) == 0x05);
1418 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
1420 else if (op2
== 0x03)
1422 // addl XX,%reg ==> addl $YY,%reg
1423 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1424 (op1
& 0xc7) == 0x05);
1426 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
1429 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
, 0);
1434 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
1435 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
1436 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
1437 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -2);
1438 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 4);
1440 unsigned char op1
= view
[-1];
1441 unsigned char op2
= view
[-2];
1442 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1443 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
1446 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
1448 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
1450 else if (op2
== 0x2b)
1452 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
1454 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
1456 else if (op2
== 0x03)
1458 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
1460 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
1463 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
, 0);
1466 value
= tls_segment
->vaddr() + tls_segment
->memsz() - value
;
1467 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
1470 Relocate_functions
<32, false>::rel32(view
, value
);
1473 // Do a relocation in which we convert a TLS Global-Dynamic to a
1477 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
1479 Output_segment
* tls_segment
,
1480 const elfcpp::Rel
<32, false>& rel
,
1482 elfcpp::Elf_types
<32>::Elf_Addr value
,
1483 unsigned char* view
,
1486 // leal foo(,%reg,1),%eax; call ___tls_get_addr
1487 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1488 // leal foo(%reg),%eax; call ___tls_get_addr
1489 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1491 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -2);
1492 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 9);
1494 unsigned char op1
= view
[-1];
1495 unsigned char op2
= view
[-2];
1497 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1498 op2
== 0x8d || op2
== 0x04);
1499 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1506 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -3);
1507 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1509 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1510 ((op1
& 0xc7) == 0x05
1511 && op1
!= (4 << 3)));
1512 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1516 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1517 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
1518 if (static_cast<off_t
>(rel
.get_r_offset() + 9) < view_size
1521 // There is a trailing nop. Use the size byte subl.
1522 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1527 // Use the five byte subl.
1528 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1532 value
= tls_segment
->vaddr() + tls_segment
->memsz() - value
;
1533 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
1535 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1537 this->skip_call_tls_get_addr_
= true;
1540 // Do a relocation in which we convert a TLS Local-Dynamic to a
1544 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
1547 const elfcpp::Rel
<32, false>& rel
,
1549 elfcpp::Elf_types
<32>::Elf_Addr
,
1550 unsigned char* view
,
1553 // leal foo(%reg), %eax; call ___tls_get_addr
1554 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
1556 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -2);
1557 Target_i386::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 9);
1559 // FIXME: Does this test really always pass?
1560 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1561 view
[-2] == 0x8d && view
[-1] == 0x83);
1563 Target_i386::Relocate::check_tls(relinfo
, relnum
, rel
,
1566 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
1568 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1570 this->skip_call_tls_get_addr_
= true;
1573 // Check the range for a TLS relocation.
1576 Target_i386::Relocate::check_range(const Relocate_info
<32, false>* relinfo
,
1578 const elfcpp::Rel
<32, false>& rel
,
1579 off_t view_size
, off_t off
)
1581 off_t offset
= rel
.get_r_offset() + off
;
1582 if (offset
< 0 || offset
> view_size
)
1584 fprintf(stderr
, _("%s: %s: TLS relocation out of range\n"),
1586 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1591 // Check the validity of a TLS relocation. This is like assert.
1594 Target_i386::Relocate::check_tls(const Relocate_info
<32, false>* relinfo
,
1596 const elfcpp::Rel
<32, false>& rel
,
1602 _("%s: %s: TLS relocation against invalid instruction\n"),
1604 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1609 // Relocate section data.
1612 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
1613 unsigned int sh_type
,
1614 const unsigned char* prelocs
,
1616 unsigned char* view
,
1617 elfcpp::Elf_types
<32>::Elf_Addr address
,
1620 gold_assert(sh_type
== elfcpp::SHT_REL
);
1622 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
1623 Target_i386::Relocate
>(
1633 // Return the value to use for a dynamic which requires special
1634 // treatment. This is how we support equality comparisons of function
1635 // pointers across shared library boundaries, as described in the
1636 // processor specific ABI supplement.
1639 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
1641 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
1642 return this->plt_section()->address() + gsym
->plt_offset();
1645 // Return a string used to fill a code section with nops to take up
1646 // the specified length.
1649 Target_i386::do_code_fill(off_t length
)
1653 // Build a jmp instruction to skip over the bytes.
1654 unsigned char jmp
[5];
1656 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
1657 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
1658 + std::string(length
- 5, '\0'));
1661 // Nop sequences of various lengths.
1662 const char nop1
[1] = { 0x90 }; // nop
1663 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
1664 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1665 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1666 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1667 0x00 }; // leal 0(%esi,1),%esi
1668 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1670 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1672 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1673 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1674 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1675 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1677 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1678 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1680 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1681 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1683 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1684 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1685 0x00, 0x00, 0x00, 0x00 };
1686 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1687 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1688 0x27, 0x00, 0x00, 0x00,
1690 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1691 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1692 0xbc, 0x27, 0x00, 0x00,
1694 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1695 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1696 0x90, 0x90, 0x90, 0x90,
1699 const char* nops
[16] = {
1701 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
1702 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
1705 return std::string(nops
[length
], length
);
1708 // The selector for i386 object files.
1710 class Target_selector_i386
: public Target_selector
1713 Target_selector_i386()
1714 : Target_selector(elfcpp::EM_386
, 32, false)
1718 recognize(int machine
, int osabi
, int abiversion
);
1721 Target_i386
* target_
;
1724 // Recognize an i386 object file when we already know that the machine
1725 // number is EM_386.
1728 Target_selector_i386::recognize(int, int, int)
1730 if (this->target_
== NULL
)
1731 this->target_
= new Target_i386();
1732 return this->target_
;
1735 Target_selector_i386 target_selector_i386
;
1737 } // End anonymous namespace.