1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright (C) 2006-2019 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.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
51 // A class to handle the .got.plt section.
53 class Output_data_got_plt_x86_64
: public Output_section_data_build
56 Output_data_got_plt_x86_64(Layout
* layout
)
57 : Output_section_data_build(8),
61 Output_data_got_plt_x86_64(Layout
* layout
, off_t data_size
)
62 : Output_section_data_build(data_size
, 8),
67 // Write out the PLT data.
69 do_write(Output_file
*);
71 // Write to a map file.
73 do_print_to_mapfile(Mapfile
* mapfile
) const
74 { mapfile
->print_output_data(this, "** GOT PLT"); }
77 // A pointer to the Layout class, so that we can find the .dynamic
78 // section when we write out the GOT PLT section.
82 // A class to handle the PLT data.
83 // This is an abstract base class that handles most of the linker details
84 // but does not know the actual contents of PLT entries. The derived
85 // classes below fill in those details.
88 class Output_data_plt_x86_64
: public Output_section_data
91 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, size
, false> Reloc_section
;
93 Output_data_plt_x86_64(Layout
* layout
, uint64_t addralign
,
94 Output_data_got
<64, false>* got
,
95 Output_data_got_plt_x86_64
* got_plt
,
96 Output_data_space
* got_irelative
)
97 : Output_section_data(addralign
), tlsdesc_rel_(NULL
),
98 irelative_rel_(NULL
), got_(got
), got_plt_(got_plt
),
99 got_irelative_(got_irelative
), count_(0), irelative_count_(0),
100 tlsdesc_got_offset_(-1U), free_list_()
101 { this->init(layout
); }
103 Output_data_plt_x86_64(Layout
* layout
, uint64_t plt_entry_size
,
104 Output_data_got
<64, false>* got
,
105 Output_data_got_plt_x86_64
* got_plt
,
106 Output_data_space
* got_irelative
,
107 unsigned int plt_count
)
108 : Output_section_data((plt_count
+ 1) * plt_entry_size
,
109 plt_entry_size
, false),
110 tlsdesc_rel_(NULL
), irelative_rel_(NULL
), got_(got
),
111 got_plt_(got_plt
), got_irelative_(got_irelative
), count_(plt_count
),
112 irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
116 // Initialize the free list and reserve the first entry.
117 this->free_list_
.init((plt_count
+ 1) * plt_entry_size
, false);
118 this->free_list_
.remove(0, plt_entry_size
);
121 // Initialize the PLT section.
123 init(Layout
* layout
);
125 // Add an entry to the PLT.
127 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
129 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
131 add_local_ifunc_entry(Symbol_table
* symtab
, Layout
*,
132 Sized_relobj_file
<size
, false>* relobj
,
133 unsigned int local_sym_index
);
135 // Add the relocation for a PLT entry.
137 add_relocation(Symbol_table
*, Layout
*, Symbol
* gsym
,
138 unsigned int got_offset
);
140 // Add the reserved TLSDESC_PLT entry to the PLT.
142 reserve_tlsdesc_entry(unsigned int got_offset
)
143 { this->tlsdesc_got_offset_
= got_offset
; }
145 // Return true if a TLSDESC_PLT entry has been reserved.
147 has_tlsdesc_entry() const
148 { return this->tlsdesc_got_offset_
!= -1U; }
150 // Return the GOT offset for the reserved TLSDESC_PLT entry.
152 get_tlsdesc_got_offset() const
153 { return this->tlsdesc_got_offset_
; }
155 // Return the offset of the reserved TLSDESC_PLT entry.
157 get_tlsdesc_plt_offset() const
159 return ((this->count_
+ this->irelative_count_
+ 1)
160 * this->get_plt_entry_size());
163 // Return the .rela.plt section data.
166 { return this->rel_
; }
168 // Return where the TLSDESC relocations should go.
170 rela_tlsdesc(Layout
*);
172 // Return where the IRELATIVE relocations should go in the PLT
175 rela_irelative(Symbol_table
*, Layout
*);
177 // Return whether we created a section for IRELATIVE relocations.
179 has_irelative_section() const
180 { return this->irelative_rel_
!= NULL
; }
182 // Get count of regular PLT entries.
184 regular_count() const
185 { return this->count_
; }
187 // Return the total number of PLT entries.
190 { return this->count_
+ this->irelative_count_
; }
192 // Return the offset of the first non-reserved PLT entry.
194 first_plt_entry_offset()
195 { return this->get_plt_entry_size(); }
197 // Return the size of a PLT entry.
199 get_plt_entry_size() const
200 { return this->do_get_plt_entry_size(); }
202 // Reserve a slot in the PLT for an existing symbol in an incremental update.
204 reserve_slot(unsigned int plt_index
)
206 this->free_list_
.remove((plt_index
+ 1) * this->get_plt_entry_size(),
207 (plt_index
+ 2) * this->get_plt_entry_size());
210 // Return the PLT address to use for a global symbol.
212 address_for_global(const Symbol
* sym
)
213 { return do_address_for_global(sym
); }
215 // Return the PLT address to use for a local symbol.
217 address_for_local(const Relobj
* obj
, unsigned int symndx
)
218 { return do_address_for_local(obj
, symndx
); }
220 // Add .eh_frame information for the PLT.
222 add_eh_frame(Layout
* layout
)
223 { this->do_add_eh_frame(layout
); }
226 Output_data_got
<64, false>*
228 { return this->got_
; }
230 Output_data_got_plt_x86_64
*
232 { return this->got_plt_
; }
235 got_irelative() const
236 { return this->got_irelative_
; }
238 // Fill in the first PLT entry.
240 fill_first_plt_entry(unsigned char* pov
,
241 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
242 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
243 { this->do_fill_first_plt_entry(pov
, got_address
, plt_address
); }
245 // Fill in a normal PLT entry. Returns the offset into the entry that
246 // should be the initial GOT slot value.
248 fill_plt_entry(unsigned char* pov
,
249 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
250 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
251 unsigned int got_offset
,
252 unsigned int plt_offset
,
253 unsigned int plt_index
)
255 return this->do_fill_plt_entry(pov
, got_address
, plt_address
,
256 got_offset
, plt_offset
, plt_index
);
259 // Fill in the reserved TLSDESC PLT entry.
261 fill_tlsdesc_entry(unsigned char* pov
,
262 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
263 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
264 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
265 unsigned int tlsdesc_got_offset
,
266 unsigned int plt_offset
)
268 this->do_fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
269 tlsdesc_got_offset
, plt_offset
);
273 do_get_plt_entry_size() const = 0;
276 do_fill_first_plt_entry(unsigned char* pov
,
277 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
278 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
)
282 do_fill_plt_entry(unsigned char* pov
,
283 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
284 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
285 unsigned int got_offset
,
286 unsigned int plt_offset
,
287 unsigned int plt_index
) = 0;
290 do_fill_tlsdesc_entry(unsigned char* pov
,
291 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
292 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
293 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
294 unsigned int tlsdesc_got_offset
,
295 unsigned int plt_offset
) = 0;
297 // Return the PLT address to use for a global symbol.
299 do_address_for_global(const Symbol
* sym
);
301 // Return the PLT address to use for a local symbol.
303 do_address_for_local(const Relobj
* obj
, unsigned int symndx
);
306 do_add_eh_frame(Layout
* layout
) = 0;
309 do_adjust_output_section(Output_section
* os
);
311 // Write to a map file.
313 do_print_to_mapfile(Mapfile
* mapfile
) const
314 { mapfile
->print_output_data(this, _("** PLT")); }
316 // The CIE of the .eh_frame unwind information for the PLT.
317 static const int plt_eh_frame_cie_size
= 16;
318 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
321 // Set the final size.
323 set_final_data_size();
325 // Write out the PLT data.
327 do_write(Output_file
*);
329 // The reloc section.
331 // The TLSDESC relocs, if necessary. These must follow the regular
333 Reloc_section
* tlsdesc_rel_
;
334 // The IRELATIVE relocs, if necessary. These must follow the
335 // regular PLT relocations and the TLSDESC relocations.
336 Reloc_section
* irelative_rel_
;
338 Output_data_got
<64, false>* got_
;
339 // The .got.plt section.
340 Output_data_got_plt_x86_64
* got_plt_
;
341 // The part of the .got.plt section used for IRELATIVE relocs.
342 Output_data_space
* got_irelative_
;
343 // The number of PLT entries.
345 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
346 // follow the regular PLT entries.
347 unsigned int irelative_count_
;
348 // Offset of the reserved TLSDESC_GOT entry when needed.
349 unsigned int tlsdesc_got_offset_
;
350 // List of available regions within the section, for incremental
352 Free_list free_list_
;
356 class Output_data_plt_x86_64_standard
: public Output_data_plt_x86_64
<size
>
359 Output_data_plt_x86_64_standard(Layout
* layout
,
360 Output_data_got
<64, false>* got
,
361 Output_data_got_plt_x86_64
* got_plt
,
362 Output_data_space
* got_irelative
)
363 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
364 got
, got_plt
, got_irelative
)
367 Output_data_plt_x86_64_standard(Layout
* layout
,
368 Output_data_got
<64, false>* got
,
369 Output_data_got_plt_x86_64
* got_plt
,
370 Output_data_space
* got_irelative
,
371 unsigned int plt_count
)
372 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
373 got
, got_plt
, got_irelative
,
379 do_get_plt_entry_size() const
380 { return plt_entry_size
; }
383 do_add_eh_frame(Layout
* layout
)
385 layout
->add_eh_frame_for_plt(this,
386 this->plt_eh_frame_cie
,
387 this->plt_eh_frame_cie_size
,
389 plt_eh_frame_fde_size
);
393 do_fill_first_plt_entry(unsigned char* pov
,
394 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
395 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
398 do_fill_plt_entry(unsigned char* pov
,
399 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
400 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
401 unsigned int got_offset
,
402 unsigned int plt_offset
,
403 unsigned int plt_index
);
406 do_fill_tlsdesc_entry(unsigned char* pov
,
407 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
408 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
409 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
410 unsigned int tlsdesc_got_offset
,
411 unsigned int plt_offset
);
414 // The size of an entry in the PLT.
415 static const int plt_entry_size
= 16;
417 // The first entry in the PLT.
418 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
419 // procedure linkage table for both programs and shared objects."
420 static const unsigned char first_plt_entry
[plt_entry_size
];
422 // Other entries in the PLT for an executable.
423 static const unsigned char plt_entry
[plt_entry_size
];
425 // The reserved TLSDESC entry in the PLT for an executable.
426 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
428 // The .eh_frame unwind information for the PLT.
429 static const int plt_eh_frame_fde_size
= 32;
430 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
433 class Output_data_plt_x86_64_bnd
: public Output_data_plt_x86_64
<64>
436 Output_data_plt_x86_64_bnd(Layout
* layout
,
437 Output_data_got
<64, false>* got
,
438 Output_data_got_plt_x86_64
* got_plt
,
439 Output_data_space
* got_irelative
)
440 : Output_data_plt_x86_64
<64>(layout
, plt_entry_size
,
441 got
, got_plt
, got_irelative
),
445 Output_data_plt_x86_64_bnd(Layout
* layout
,
446 Output_data_got
<64, false>* got
,
447 Output_data_got_plt_x86_64
* got_plt
,
448 Output_data_space
* got_irelative
,
449 unsigned int plt_count
)
450 : Output_data_plt_x86_64
<64>(layout
, plt_entry_size
,
451 got
, got_plt
, got_irelative
,
458 do_get_plt_entry_size() const
459 { return plt_entry_size
; }
461 // Return the PLT address to use for a global symbol.
463 do_address_for_global(const Symbol
*);
465 // Return the PLT address to use for a local symbol.
467 do_address_for_local(const Relobj
*, unsigned int symndx
);
470 do_add_eh_frame(Layout
* layout
)
472 layout
->add_eh_frame_for_plt(this,
473 this->plt_eh_frame_cie
,
474 this->plt_eh_frame_cie_size
,
476 plt_eh_frame_fde_size
);
480 do_fill_first_plt_entry(unsigned char* pov
,
481 elfcpp::Elf_types
<64>::Elf_Addr got_addr
,
482 elfcpp::Elf_types
<64>::Elf_Addr plt_addr
);
485 do_fill_plt_entry(unsigned char* pov
,
486 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
487 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
488 unsigned int got_offset
,
489 unsigned int plt_offset
,
490 unsigned int plt_index
);
493 do_fill_tlsdesc_entry(unsigned char* pov
,
494 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
495 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
496 elfcpp::Elf_types
<64>::Elf_Addr got_base
,
497 unsigned int tlsdesc_got_offset
,
498 unsigned int plt_offset
);
501 fill_aplt_entry(unsigned char* pov
,
502 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
503 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
504 unsigned int got_offset
,
505 unsigned int plt_offset
,
506 unsigned int plt_index
);
509 // Set the final size.
511 set_final_data_size();
513 // Write out the BND PLT data.
515 do_write(Output_file
*);
517 // Offset of the Additional PLT (if using -z bndplt).
518 unsigned int aplt_offset_
;
520 // The size of an entry in the PLT.
521 static const int plt_entry_size
= 16;
523 // The size of an entry in the additional PLT.
524 static const int aplt_entry_size
= 8;
526 // The first entry in the PLT.
527 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
528 // procedure linkage table for both programs and shared objects."
529 static const unsigned char first_plt_entry
[plt_entry_size
];
531 // Other entries in the PLT for an executable.
532 static const unsigned char plt_entry
[plt_entry_size
];
534 // Entries in the additional PLT.
535 static const unsigned char aplt_entry
[aplt_entry_size
];
537 // The reserved TLSDESC entry in the PLT for an executable.
538 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
540 // The .eh_frame unwind information for the PLT.
541 static const int plt_eh_frame_fde_size
= 32;
542 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
545 // We use this PLT when Indirect Branch Tracking (IBT) is enabled.
548 class Output_data_plt_x86_64_ibt
: public Output_data_plt_x86_64
<size
>
551 Output_data_plt_x86_64_ibt(Layout
* layout
,
552 Output_data_got
<64, false>* got
,
553 Output_data_got_plt_x86_64
* got_plt
,
554 Output_data_space
* got_irelative
)
555 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
556 got
, got_plt
, got_irelative
),
560 Output_data_plt_x86_64_ibt(Layout
* layout
,
561 Output_data_got
<64, false>* got
,
562 Output_data_got_plt_x86_64
* got_plt
,
563 Output_data_space
* got_irelative
,
564 unsigned int plt_count
)
565 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
566 got
, got_plt
, got_irelative
,
573 do_get_plt_entry_size() const
574 { return plt_entry_size
; }
576 // Return the PLT address to use for a global symbol.
578 do_address_for_global(const Symbol
*);
580 // Return the PLT address to use for a local symbol.
582 do_address_for_local(const Relobj
*, unsigned int symndx
);
585 do_add_eh_frame(Layout
* layout
)
587 layout
->add_eh_frame_for_plt(this,
588 this->plt_eh_frame_cie
,
589 this->plt_eh_frame_cie_size
,
591 plt_eh_frame_fde_size
);
595 do_fill_first_plt_entry(unsigned char* pov
,
596 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
597 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
600 do_fill_plt_entry(unsigned char* pov
,
601 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
602 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
603 unsigned int got_offset
,
604 unsigned int plt_offset
,
605 unsigned int plt_index
);
608 do_fill_tlsdesc_entry(unsigned char* pov
,
609 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
610 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
611 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
612 unsigned int tlsdesc_got_offset
,
613 unsigned int plt_offset
);
616 fill_aplt_entry(unsigned char* pov
,
617 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
618 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
619 unsigned int got_offset
,
620 unsigned int plt_offset
,
621 unsigned int plt_index
);
624 // Set the final size.
626 set_final_data_size();
628 // Write out the BND PLT data.
630 do_write(Output_file
*);
632 // Offset of the Additional PLT (if using -z bndplt).
633 unsigned int aplt_offset_
;
635 // The size of an entry in the PLT.
636 static const int plt_entry_size
= 16;
638 // The size of an entry in the additional PLT.
639 static const int aplt_entry_size
= 16;
641 // The first entry in the PLT.
642 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
643 // procedure linkage table for both programs and shared objects."
644 static const unsigned char first_plt_entry
[plt_entry_size
];
646 // Other entries in the PLT for an executable.
647 static const unsigned char plt_entry
[plt_entry_size
];
649 // Entries in the additional PLT.
650 static const unsigned char aplt_entry
[aplt_entry_size
];
652 // The reserved TLSDESC entry in the PLT for an executable.
653 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
655 // The .eh_frame unwind information for the PLT.
656 static const int plt_eh_frame_fde_size
= 32;
657 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
664 Lazy_view(Sized_relobj_file
<size
, false>* object
, unsigned int data_shndx
)
665 : object_(object
), data_shndx_(data_shndx
), view_(NULL
), view_size_(0)
669 operator[](size_t offset
)
671 if (this->view_
== NULL
)
672 this->view_
= this->object_
->section_contents(this->data_shndx_
,
675 if (offset
>= this->view_size_
)
677 return this->view_
[offset
];
681 Sized_relobj_file
<size
, false>* object_
;
682 unsigned int data_shndx_
;
683 const unsigned char* view_
;
684 section_size_type view_size_
;
687 // The x86_64 target class.
689 // http://www.x86-64.org/documentation/abi.pdf
690 // TLS info comes from
691 // http://people.redhat.com/drepper/tls.pdf
692 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
695 class Target_x86_64
: public Sized_target
<size
, false>
698 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
699 // uses only Elf64_Rela relocation entries with explicit addends."
700 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, size
, false> Reloc_section
;
702 Target_x86_64(const Target::Target_info
* info
= &x86_64_info
)
703 : Sized_target
<size
, false>(info
),
704 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
705 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rela_dyn_(NULL
),
706 rela_irelative_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
),
707 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
708 tls_base_symbol_defined_(false), isa_1_used_(0), isa_1_needed_(0),
709 feature_1_(0), object_isa_1_used_(0), object_feature_1_(0),
710 seen_first_object_(false)
713 // Hook for a new output section.
715 do_new_output_section(Output_section
*) const;
717 // Scan the relocations to look for symbol adjustments.
719 gc_process_relocs(Symbol_table
* symtab
,
721 Sized_relobj_file
<size
, false>* object
,
722 unsigned int data_shndx
,
723 unsigned int sh_type
,
724 const unsigned char* prelocs
,
726 Output_section
* output_section
,
727 bool needs_special_offset_handling
,
728 size_t local_symbol_count
,
729 const unsigned char* plocal_symbols
);
731 // Scan the relocations to look for symbol adjustments.
733 scan_relocs(Symbol_table
* symtab
,
735 Sized_relobj_file
<size
, false>* object
,
736 unsigned int data_shndx
,
737 unsigned int sh_type
,
738 const unsigned char* prelocs
,
740 Output_section
* output_section
,
741 bool needs_special_offset_handling
,
742 size_t local_symbol_count
,
743 const unsigned char* plocal_symbols
);
745 // Finalize the sections.
747 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
749 // Return the value to use for a dynamic which requires special
752 do_dynsym_value(const Symbol
*) const;
754 // Relocate a section.
756 relocate_section(const Relocate_info
<size
, false>*,
757 unsigned int sh_type
,
758 const unsigned char* prelocs
,
760 Output_section
* output_section
,
761 bool needs_special_offset_handling
,
763 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
764 section_size_type view_size
,
765 const Reloc_symbol_changes
*);
767 // Scan the relocs during a relocatable link.
769 scan_relocatable_relocs(Symbol_table
* symtab
,
771 Sized_relobj_file
<size
, false>* object
,
772 unsigned int data_shndx
,
773 unsigned int sh_type
,
774 const unsigned char* prelocs
,
776 Output_section
* output_section
,
777 bool needs_special_offset_handling
,
778 size_t local_symbol_count
,
779 const unsigned char* plocal_symbols
,
780 Relocatable_relocs
*);
782 // Scan the relocs for --emit-relocs.
784 emit_relocs_scan(Symbol_table
* symtab
,
786 Sized_relobj_file
<size
, false>* object
,
787 unsigned int data_shndx
,
788 unsigned int sh_type
,
789 const unsigned char* prelocs
,
791 Output_section
* output_section
,
792 bool needs_special_offset_handling
,
793 size_t local_symbol_count
,
794 const unsigned char* plocal_syms
,
795 Relocatable_relocs
* rr
);
797 // Emit relocations for a section.
800 const Relocate_info
<size
, false>*,
801 unsigned int sh_type
,
802 const unsigned char* prelocs
,
804 Output_section
* output_section
,
805 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
807 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
808 section_size_type view_size
,
809 unsigned char* reloc_view
,
810 section_size_type reloc_view_size
);
812 // Return a string used to fill a code section with nops.
814 do_code_fill(section_size_type length
) const;
816 // Return whether SYM is defined by the ABI.
818 do_is_defined_by_abi(const Symbol
* sym
) const
819 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
821 // Return the symbol index to use for a target specific relocation.
822 // The only target specific relocation is R_X86_64_TLSDESC for a
823 // local symbol, which is an absolute reloc.
825 do_reloc_symbol_index(void*, unsigned int r_type
) const
827 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
831 // Return the addend to use for a target specific relocation.
833 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
835 // Return the PLT section.
837 do_plt_address_for_global(const Symbol
* gsym
) const
838 { return this->plt_section()->address_for_global(gsym
); }
841 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
842 { return this->plt_section()->address_for_local(relobj
, symndx
); }
844 // This function should be defined in targets that can use relocation
845 // types to determine (implemented in local_reloc_may_be_function_pointer
846 // and global_reloc_may_be_function_pointer)
847 // if a function's pointer is taken. ICF uses this in safe mode to only
848 // fold those functions whose pointer is defintely not taken. For x86_64
849 // pie binaries, safe ICF cannot be done by looking at only relocation
850 // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
851 // opcode is checked as well to distinguish a function call from taking
852 // a function's pointer.
854 do_can_check_for_function_pointers() const
857 // Return the base for a DW_EH_PE_datarel encoding.
859 do_ehframe_datarel_base() const;
861 // Adjust -fsplit-stack code which calls non-split-stack code.
863 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
864 section_offset_type fnoffset
, section_size_type fnsize
,
865 const unsigned char* prelocs
, size_t reloc_count
,
866 unsigned char* view
, section_size_type view_size
,
867 std::string
* from
, std::string
* to
) const;
869 // Return the size of the GOT section.
873 gold_assert(this->got_
!= NULL
);
874 return this->got_
->data_size();
877 // Return the number of entries in the GOT.
879 got_entry_count() const
881 if (this->got_
== NULL
)
883 return this->got_size() / 8;
886 // Return the number of entries in the PLT.
888 plt_entry_count() const;
890 // Return the offset of the first non-reserved PLT entry.
892 first_plt_entry_offset() const;
894 // Return the size of each PLT entry.
896 plt_entry_size() const;
898 // Return the size of each GOT entry.
900 got_entry_size() const
903 // Create the GOT section for an incremental update.
904 Output_data_got_base
*
905 init_got_plt_for_update(Symbol_table
* symtab
,
907 unsigned int got_count
,
908 unsigned int plt_count
);
910 // Reserve a GOT entry for a local symbol, and regenerate any
911 // necessary dynamic relocations.
913 reserve_local_got_entry(unsigned int got_index
,
914 Sized_relobj
<size
, false>* obj
,
916 unsigned int got_type
);
918 // Reserve a GOT entry for a global symbol, and regenerate any
919 // necessary dynamic relocations.
921 reserve_global_got_entry(unsigned int got_index
, Symbol
* gsym
,
922 unsigned int got_type
);
924 // Register an existing PLT entry for a global symbol.
926 register_global_plt_entry(Symbol_table
*, Layout
*, unsigned int plt_index
,
929 // Force a COPY relocation for a given symbol.
931 emit_copy_reloc(Symbol_table
*, Symbol
*, Output_section
*, off_t
);
933 // Apply an incremental relocation.
935 apply_relocation(const Relocate_info
<size
, false>* relinfo
,
936 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
938 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
941 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
942 section_size_type view_size
);
944 // Add a new reloc argument, returning the index in the vector.
946 add_tlsdesc_info(Sized_relobj_file
<size
, false>* object
, unsigned int r_sym
)
948 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
949 return this->tlsdesc_reloc_info_
.size() - 1;
952 Output_data_plt_x86_64
<size
>*
953 make_data_plt(Layout
* layout
,
954 Output_data_got
<64, false>* got
,
955 Output_data_got_plt_x86_64
* got_plt
,
956 Output_data_space
* got_irelative
)
958 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
);
961 Output_data_plt_x86_64
<size
>*
962 make_data_plt(Layout
* layout
,
963 Output_data_got
<64, false>* got
,
964 Output_data_got_plt_x86_64
* got_plt
,
965 Output_data_space
* got_irelative
,
966 unsigned int plt_count
)
968 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
,
972 virtual Output_data_plt_x86_64
<size
>*
973 do_make_data_plt(Layout
* layout
,
974 Output_data_got
<64, false>* got
,
975 Output_data_got_plt_x86_64
* got_plt
,
976 Output_data_space
* got_irelative
);
978 virtual Output_data_plt_x86_64
<size
>*
979 do_make_data_plt(Layout
* layout
,
980 Output_data_got
<64, false>* got
,
981 Output_data_got_plt_x86_64
* got_plt
,
982 Output_data_space
* got_irelative
,
983 unsigned int plt_count
);
986 // The class which scans relocations.
991 : issued_non_pic_error_(false)
995 get_reference_flags(unsigned int r_type
);
998 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
999 Sized_relobj_file
<size
, false>* object
,
1000 unsigned int data_shndx
,
1001 Output_section
* output_section
,
1002 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
1003 const elfcpp::Sym
<size
, false>& lsym
,
1007 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
1008 Sized_relobj_file
<size
, false>* object
,
1009 unsigned int data_shndx
,
1010 Output_section
* output_section
,
1011 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
1015 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
1016 Target_x86_64
* target
,
1017 Sized_relobj_file
<size
, false>* object
,
1018 unsigned int data_shndx
,
1019 Output_section
* output_section
,
1020 const elfcpp::Rela
<size
, false>& reloc
,
1021 unsigned int r_type
,
1022 const elfcpp::Sym
<size
, false>& lsym
);
1025 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
1026 Target_x86_64
* target
,
1027 Sized_relobj_file
<size
, false>* object
,
1028 unsigned int data_shndx
,
1029 Output_section
* output_section
,
1030 const elfcpp::Rela
<size
, false>& reloc
,
1031 unsigned int r_type
,
1036 unsupported_reloc_local(Sized_relobj_file
<size
, false>*,
1037 unsigned int r_type
);
1040 unsupported_reloc_global(Sized_relobj_file
<size
, false>*,
1041 unsigned int r_type
, Symbol
*);
1044 check_non_pic(Relobj
*, unsigned int r_type
, Symbol
*);
1047 possible_function_pointer_reloc(Sized_relobj_file
<size
, false>* src_obj
,
1048 unsigned int src_indx
,
1049 unsigned int r_offset
,
1050 unsigned int r_type
);
1053 reloc_needs_plt_for_ifunc(Sized_relobj_file
<size
, false>*,
1054 unsigned int r_type
);
1056 // Whether we have issued an error about a non-PIC compilation.
1057 bool issued_non_pic_error_
;
1060 // The class which implements relocation.
1065 : skip_call_tls_get_addr_(false)
1070 if (this->skip_call_tls_get_addr_
)
1072 // FIXME: This needs to specify the location somehow.
1073 gold_error(_("missing expected TLS relocation"));
1077 // Do a relocation. Return false if the caller should not issue
1078 // any warnings about this relocation.
1080 relocate(const Relocate_info
<size
, false>*, unsigned int,
1081 Target_x86_64
*, Output_section
*, size_t, const unsigned char*,
1082 const Sized_symbol
<size
>*, const Symbol_value
<size
>*,
1083 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1087 // Do a TLS relocation.
1089 relocate_tls(const Relocate_info
<size
, false>*, Target_x86_64
*,
1090 size_t relnum
, const elfcpp::Rela
<size
, false>&,
1091 unsigned int r_type
, const Sized_symbol
<size
>*,
1092 const Symbol_value
<size
>*,
1093 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1096 // Do a TLS General-Dynamic to Initial-Exec transition.
1098 tls_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
1099 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1100 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1101 unsigned char* view
,
1102 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1103 section_size_type view_size
);
1105 // Do a TLS General-Dynamic to Local-Exec transition.
1107 tls_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1108 Output_segment
* tls_segment
,
1109 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1110 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1111 unsigned char* view
,
1112 section_size_type view_size
);
1114 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
1116 tls_desc_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
1117 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1118 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1119 unsigned char* view
,
1120 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1121 section_size_type view_size
);
1123 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1125 tls_desc_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1126 Output_segment
* tls_segment
,
1127 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1128 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1129 unsigned char* view
,
1130 section_size_type view_size
);
1132 // Do a TLS Local-Dynamic to Local-Exec transition.
1134 tls_ld_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1135 Output_segment
* tls_segment
,
1136 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1137 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1138 unsigned char* view
,
1139 section_size_type view_size
);
1141 // Do a TLS Initial-Exec to Local-Exec transition.
1143 tls_ie_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1144 Output_segment
* tls_segment
,
1145 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1146 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1147 unsigned char* view
,
1148 section_size_type view_size
);
1150 // This is set if we should skip the next reloc, which should be a
1151 // PLT32 reloc against ___tls_get_addr.
1152 bool skip_call_tls_get_addr_
;
1155 // Check if relocation against this symbol is a candidate for
1157 // mov foo@GOTPCREL(%rip), %reg
1158 // to lea foo(%rip), %reg.
1159 template<class View_type
>
1161 can_convert_mov_to_lea(const Symbol
* gsym
, unsigned int r_type
,
1162 size_t r_offset
, View_type
* view
)
1164 gold_assert(gsym
!= NULL
);
1165 // We cannot do the conversion unless it's one of these relocations.
1166 if (r_type
!= elfcpp::R_X86_64_GOTPCREL
1167 && r_type
!= elfcpp::R_X86_64_GOTPCRELX
1168 && r_type
!= elfcpp::R_X86_64_REX_GOTPCRELX
)
1170 // We cannot convert references to IFUNC symbols, or to symbols that
1171 // are not local to the current module.
1172 // We can't do predefined symbols because they may become undefined
1173 // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1174 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1175 || gsym
->is_undefined()
1176 || gsym
->is_predefined()
1177 || gsym
->is_from_dynobj()
1178 || gsym
->is_preemptible())
1180 // If we are building a shared object and the symbol is protected, we may
1181 // need to go through the GOT.
1182 if (parameters
->options().shared()
1183 && gsym
->visibility() == elfcpp::STV_PROTECTED
)
1185 // We cannot convert references to the _DYNAMIC symbol.
1186 if (strcmp(gsym
->name(), "_DYNAMIC") == 0)
1188 // Check for a MOV opcode.
1189 return (*view
)[r_offset
- 2] == 0x8b;
1193 // callq *foo@GOTPCRELX(%rip) to
1195 // and jmpq *foo@GOTPCRELX(%rip) to
1198 template<class View_type
>
1200 can_convert_callq_to_direct(const Symbol
* gsym
, unsigned int r_type
,
1201 size_t r_offset
, View_type
* view
)
1203 gold_assert(gsym
!= NULL
);
1204 // We cannot do the conversion unless it's a GOTPCRELX relocation.
1205 if (r_type
!= elfcpp::R_X86_64_GOTPCRELX
)
1207 // We cannot convert references to IFUNC symbols, or to symbols that
1208 // are not local to the current module.
1209 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1210 || gsym
->is_undefined ()
1211 || gsym
->is_from_dynobj()
1212 || gsym
->is_preemptible())
1214 // Check for a CALLQ or JMPQ opcode.
1215 return ((*view
)[r_offset
- 2] == 0xff
1216 && ((*view
)[r_offset
- 1] == 0x15
1217 || (*view
)[r_offset
- 1] == 0x25));
1220 // Adjust TLS relocation type based on the options and whether this
1221 // is a local symbol.
1222 static tls::Tls_optimization
1223 optimize_tls_reloc(bool is_final
, int r_type
);
1225 // Get the GOT section, creating it if necessary.
1226 Output_data_got
<64, false>*
1227 got_section(Symbol_table
*, Layout
*);
1229 // Get the GOT PLT section.
1230 Output_data_got_plt_x86_64
*
1231 got_plt_section() const
1233 gold_assert(this->got_plt_
!= NULL
);
1234 return this->got_plt_
;
1237 // Get the GOT section for TLSDESC entries.
1238 Output_data_got
<64, false>*
1239 got_tlsdesc_section() const
1241 gold_assert(this->got_tlsdesc_
!= NULL
);
1242 return this->got_tlsdesc_
;
1245 // Create the PLT section.
1247 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
1249 // Create a PLT entry for a global symbol.
1251 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
1253 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1255 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
1256 Sized_relobj_file
<size
, false>* relobj
,
1257 unsigned int local_sym_index
);
1259 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1261 define_tls_base_symbol(Symbol_table
*, Layout
*);
1263 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1265 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
1267 // Create a GOT entry for the TLS module index.
1269 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1270 Sized_relobj_file
<size
, false>* object
);
1272 // Get the PLT section.
1273 Output_data_plt_x86_64
<size
>*
1276 gold_assert(this->plt_
!= NULL
);
1280 // Get the dynamic reloc section, creating it if necessary.
1282 rela_dyn_section(Layout
*);
1284 // Get the section to use for TLSDESC relocations.
1286 rela_tlsdesc_section(Layout
*) const;
1288 // Get the section to use for IRELATIVE relocations.
1290 rela_irelative_section(Layout
*);
1292 // Add a potential copy relocation.
1294 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
1295 Sized_relobj_file
<size
, false>* object
,
1296 unsigned int shndx
, Output_section
* output_section
,
1297 Symbol
* sym
, const elfcpp::Rela
<size
, false>& reloc
)
1299 unsigned int r_type
= elfcpp::elf_r_type
<size
>(reloc
.get_r_info());
1300 this->copy_relocs_
.copy_reloc(symtab
, layout
,
1301 symtab
->get_sized_symbol
<size
>(sym
),
1302 object
, shndx
, output_section
,
1303 r_type
, reloc
.get_r_offset(),
1304 reloc
.get_r_addend(),
1305 this->rela_dyn_section(layout
));
1308 // Record a target-specific program property in the .note.gnu.property
1311 record_gnu_property(unsigned int, unsigned int, size_t,
1312 const unsigned char*, const Object
*);
1314 // Merge the target-specific program properties from the current object.
1316 merge_gnu_properties(const Object
*);
1318 // Finalize the target-specific program properties and add them back to
1321 do_finalize_gnu_properties(Layout
*) const;
1323 // Information about this specific target which we pass to the
1324 // general Target structure.
1325 static const Target::Target_info x86_64_info
;
1327 // The types of GOT entries needed for this platform.
1328 // These values are exposed to the ABI in an incremental link.
1329 // Do not renumber existing values without changing the version
1330 // number of the .gnu_incremental_inputs section.
1333 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
1334 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
1335 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
1336 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
1339 // This type is used as the argument to the target specific
1340 // relocation routines. The only target specific reloc is
1341 // R_X86_64_TLSDESC against a local symbol.
1344 Tlsdesc_info(Sized_relobj_file
<size
, false>* a_object
, unsigned int a_r_sym
)
1345 : object(a_object
), r_sym(a_r_sym
)
1348 // The object in which the local symbol is defined.
1349 Sized_relobj_file
<size
, false>* object
;
1350 // The local symbol index in the object.
1355 Output_data_got
<64, false>* got_
;
1357 Output_data_plt_x86_64
<size
>* plt_
;
1358 // The GOT PLT section.
1359 Output_data_got_plt_x86_64
* got_plt_
;
1360 // The GOT section for IRELATIVE relocations.
1361 Output_data_space
* got_irelative_
;
1362 // The GOT section for TLSDESC relocations.
1363 Output_data_got
<64, false>* got_tlsdesc_
;
1364 // The _GLOBAL_OFFSET_TABLE_ symbol.
1365 Symbol
* global_offset_table_
;
1366 // The dynamic reloc section.
1367 Reloc_section
* rela_dyn_
;
1368 // The section to use for IRELATIVE relocs.
1369 Reloc_section
* rela_irelative_
;
1370 // Relocs saved to avoid a COPY reloc.
1371 Copy_relocs
<elfcpp::SHT_RELA
, size
, false> copy_relocs_
;
1372 // Offset of the GOT entry for the TLS module index.
1373 unsigned int got_mod_index_offset_
;
1374 // We handle R_X86_64_TLSDESC against a local symbol as a target
1375 // specific relocation. Here we store the object and local symbol
1376 // index for the relocation.
1377 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
1378 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1379 bool tls_base_symbol_defined_
;
1380 // Target-specific program properties, from .note.gnu.property section.
1381 // Each bit represents a specific feature.
1382 uint32_t isa_1_used_
;
1383 uint32_t isa_1_needed_
;
1384 uint32_t feature_1_
;
1385 // Target-specific properties from the current object.
1386 // These bits get ORed into ISA_1_USED_ after all properties for the object
1387 // have been processed. But if either is all zeroes (as when the property
1388 // is absent from an object), the result should be all zeroes.
1389 // (See PR ld/23486.)
1390 uint32_t object_isa_1_used_
;
1391 // These bits get ANDed into FEATURE_1_ after all properties for the object
1392 // have been processed.
1393 uint32_t object_feature_1_
;
1394 // Whether we have seen our first object, for use in initializing FEATURE_1_.
1395 bool seen_first_object_
;
1399 const Target::Target_info Target_x86_64
<64>::x86_64_info
=
1402 false, // is_big_endian
1403 elfcpp::EM_X86_64
, // machine_code
1404 false, // has_make_symbol
1405 false, // has_resolve
1406 true, // has_code_fill
1407 true, // is_default_stack_executable
1408 true, // can_icf_inline_merge_sections
1410 "/lib/ld64.so.1", // program interpreter
1411 0x400000, // default_text_segment_address
1412 0x1000, // abi_pagesize (overridable by -z max-page-size)
1413 0x1000, // common_pagesize (overridable by -z common-page-size)
1414 false, // isolate_execinstr
1416 elfcpp::SHN_UNDEF
, // small_common_shndx
1417 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1418 0, // small_common_section_flags
1419 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1420 NULL
, // attributes_section
1421 NULL
, // attributes_vendor
1422 "_start", // entry_symbol_name
1423 32, // hash_entry_size
1424 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
1428 const Target::Target_info Target_x86_64
<32>::x86_64_info
=
1431 false, // is_big_endian
1432 elfcpp::EM_X86_64
, // machine_code
1433 false, // has_make_symbol
1434 false, // has_resolve
1435 true, // has_code_fill
1436 true, // is_default_stack_executable
1437 true, // can_icf_inline_merge_sections
1439 "/libx32/ldx32.so.1", // program interpreter
1440 0x400000, // default_text_segment_address
1441 0x1000, // abi_pagesize (overridable by -z max-page-size)
1442 0x1000, // common_pagesize (overridable by -z common-page-size)
1443 false, // isolate_execinstr
1445 elfcpp::SHN_UNDEF
, // small_common_shndx
1446 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1447 0, // small_common_section_flags
1448 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1449 NULL
, // attributes_section
1450 NULL
, // attributes_vendor
1451 "_start", // entry_symbol_name
1452 32, // hash_entry_size
1453 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
1456 // This is called when a new output section is created. This is where
1457 // we handle the SHF_X86_64_LARGE.
1461 Target_x86_64
<size
>::do_new_output_section(Output_section
* os
) const
1463 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
1464 os
->set_is_large_section();
1467 // Get the GOT section, creating it if necessary.
1470 Output_data_got
<64, false>*
1471 Target_x86_64
<size
>::got_section(Symbol_table
* symtab
, Layout
* layout
)
1473 if (this->got_
== NULL
)
1475 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
1477 // When using -z now, we can treat .got.plt as a relro section.
1478 // Without -z now, it is modified after program startup by lazy
1480 bool is_got_plt_relro
= parameters
->options().now();
1481 Output_section_order got_order
= (is_got_plt_relro
1483 : ORDER_RELRO_LAST
);
1484 Output_section_order got_plt_order
= (is_got_plt_relro
1486 : ORDER_NON_RELRO_FIRST
);
1488 this->got_
= new Output_data_got
<64, false>();
1490 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1492 | elfcpp::SHF_WRITE
),
1493 this->got_
, got_order
, true);
1495 this->got_plt_
= new Output_data_got_plt_x86_64(layout
);
1496 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1498 | elfcpp::SHF_WRITE
),
1499 this->got_plt_
, got_plt_order
,
1502 // The first three entries are reserved.
1503 this->got_plt_
->set_current_data_size(3 * 8);
1505 if (!is_got_plt_relro
)
1507 // Those bytes can go into the relro segment.
1508 layout
->increase_relro(3 * 8);
1511 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1512 this->global_offset_table_
=
1513 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1514 Symbol_table::PREDEFINED
,
1516 0, 0, elfcpp::STT_OBJECT
,
1518 elfcpp::STV_HIDDEN
, 0,
1521 // If there are any IRELATIVE relocations, they get GOT entries
1522 // in .got.plt after the jump slot entries.
1523 this->got_irelative_
= new Output_data_space(8, "** GOT IRELATIVE PLT");
1524 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1526 | elfcpp::SHF_WRITE
),
1527 this->got_irelative_
,
1528 got_plt_order
, is_got_plt_relro
);
1530 // If there are any TLSDESC relocations, they get GOT entries in
1531 // .got.plt after the jump slot and IRELATIVE entries.
1532 this->got_tlsdesc_
= new Output_data_got
<64, false>();
1533 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1535 | elfcpp::SHF_WRITE
),
1537 got_plt_order
, is_got_plt_relro
);
1543 // Get the dynamic reloc section, creating it if necessary.
1546 typename Target_x86_64
<size
>::Reloc_section
*
1547 Target_x86_64
<size
>::rela_dyn_section(Layout
* layout
)
1549 if (this->rela_dyn_
== NULL
)
1551 gold_assert(layout
!= NULL
);
1552 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
1553 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1554 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
1555 ORDER_DYNAMIC_RELOCS
, false);
1557 return this->rela_dyn_
;
1560 // Get the section to use for IRELATIVE relocs, creating it if
1561 // necessary. These go in .rela.dyn, but only after all other dynamic
1562 // relocations. They need to follow the other dynamic relocations so
1563 // that they can refer to global variables initialized by those
1567 typename Target_x86_64
<size
>::Reloc_section
*
1568 Target_x86_64
<size
>::rela_irelative_section(Layout
* layout
)
1570 if (this->rela_irelative_
== NULL
)
1572 // Make sure we have already created the dynamic reloc section.
1573 this->rela_dyn_section(layout
);
1574 this->rela_irelative_
= new Reloc_section(false);
1575 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1576 elfcpp::SHF_ALLOC
, this->rela_irelative_
,
1577 ORDER_DYNAMIC_RELOCS
, false);
1578 gold_assert(this->rela_dyn_
->output_section()
1579 == this->rela_irelative_
->output_section());
1581 return this->rela_irelative_
;
1584 // Record a target-specific program property from the .note.gnu.property
1588 Target_x86_64
<size
>::record_gnu_property(
1589 unsigned int, unsigned int pr_type
,
1590 size_t pr_datasz
, const unsigned char* pr_data
,
1591 const Object
* object
)
1597 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED
:
1598 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED
:
1599 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND
:
1602 gold_warning(_("%s: corrupt .note.gnu.property section "
1603 "(pr_datasz for property %d is not 4)"),
1604 object
->name().c_str(), pr_type
);
1607 val
= elfcpp::Swap
<32, false>::readval(pr_data
);
1610 gold_warning(_("%s: unknown program property type 0x%x "
1611 "in .note.gnu.property section"),
1612 object
->name().c_str(), pr_type
);
1618 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED
:
1619 this->object_isa_1_used_
|= val
;
1621 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED
:
1622 this->isa_1_needed_
|= val
;
1624 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND
:
1625 // If we see multiple feature props in one object, OR them together.
1626 this->object_feature_1_
|= val
;
1631 // Merge the target-specific program properties from the current object.
1634 Target_x86_64
<size
>::merge_gnu_properties(const Object
*)
1636 if (this->seen_first_object_
)
1638 // If any object is missing the ISA_1_USED property, we must omit
1639 // it from the output file.
1640 if (this->object_isa_1_used_
== 0)
1641 this->isa_1_used_
= 0;
1642 else if (this->isa_1_used_
!= 0)
1643 this->isa_1_used_
|= this->object_isa_1_used_
;
1644 this->feature_1_
&= this->object_feature_1_
;
1648 this->isa_1_used_
= this->object_isa_1_used_
;
1649 this->feature_1_
= this->object_feature_1_
;
1650 this->seen_first_object_
= true;
1652 this->object_isa_1_used_
= 0;
1653 this->object_feature_1_
= 0;
1657 add_property(Layout
* layout
, unsigned int pr_type
, uint32_t val
)
1659 unsigned char buf
[4];
1660 elfcpp::Swap
<32, false>::writeval(buf
, val
);
1661 layout
->add_gnu_property(elfcpp::NT_GNU_PROPERTY_TYPE_0
, pr_type
, 4, buf
);
1664 // Finalize the target-specific program properties and add them back to
1668 Target_x86_64
<size
>::do_finalize_gnu_properties(Layout
* layout
) const
1670 if (this->isa_1_used_
!= 0)
1671 add_property(layout
, elfcpp::GNU_PROPERTY_X86_ISA_1_USED
,
1673 if (this->isa_1_needed_
!= 0)
1674 add_property(layout
, elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED
,
1675 this->isa_1_needed_
);
1676 if (this->feature_1_
!= 0)
1677 add_property(layout
, elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND
,
1681 // Write the first three reserved words of the .got.plt section.
1682 // The remainder of the section is written while writing the PLT
1683 // in Output_data_plt_i386::do_write.
1686 Output_data_got_plt_x86_64::do_write(Output_file
* of
)
1688 // The first entry in the GOT is the address of the .dynamic section
1689 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1690 // We saved space for them when we created the section in
1691 // Target_x86_64::got_section.
1692 const off_t got_file_offset
= this->offset();
1693 gold_assert(this->data_size() >= 24);
1694 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 24);
1695 Output_section
* dynamic
= this->layout_
->dynamic_section();
1696 uint64_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1697 elfcpp::Swap
<64, false>::writeval(got_view
, dynamic_addr
);
1698 memset(got_view
+ 8, 0, 16);
1699 of
->write_output_view(got_file_offset
, 24, got_view
);
1702 // Initialize the PLT section.
1706 Output_data_plt_x86_64
<size
>::init(Layout
* layout
)
1708 this->rel_
= new Reloc_section(false);
1709 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1710 elfcpp::SHF_ALLOC
, this->rel_
,
1711 ORDER_DYNAMIC_PLT_RELOCS
, false);
1716 Output_data_plt_x86_64
<size
>::do_adjust_output_section(Output_section
* os
)
1718 os
->set_entsize(this->get_plt_entry_size());
1721 // Add an entry to the PLT.
1725 Output_data_plt_x86_64
<size
>::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1728 gold_assert(!gsym
->has_plt_offset());
1730 unsigned int plt_index
;
1732 section_offset_type got_offset
;
1734 unsigned int* pcount
;
1735 unsigned int offset
;
1736 unsigned int reserved
;
1737 Output_section_data_build
* got
;
1738 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1739 && gsym
->can_use_relative_reloc(false))
1741 pcount
= &this->irelative_count_
;
1744 got
= this->got_irelative_
;
1748 pcount
= &this->count_
;
1751 got
= this->got_plt_
;
1754 if (!this->is_data_size_valid())
1756 // Note that when setting the PLT offset for a non-IRELATIVE
1757 // entry we skip the initial reserved PLT entry.
1758 plt_index
= *pcount
+ offset
;
1759 plt_offset
= plt_index
* this->get_plt_entry_size();
1763 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1764 gold_assert(got_offset
== got
->current_data_size());
1766 // Every PLT entry needs a GOT entry which points back to the PLT
1767 // entry (this will be changed by the dynamic linker, normally
1768 // lazily when the function is called).
1769 got
->set_current_data_size(got_offset
+ 8);
1773 // FIXME: This is probably not correct for IRELATIVE relocs.
1775 // For incremental updates, find an available slot.
1776 plt_offset
= this->free_list_
.allocate(this->get_plt_entry_size(),
1777 this->get_plt_entry_size(), 0);
1778 if (plt_offset
== -1)
1779 gold_fallback(_("out of patch space (PLT);"
1780 " relink with --incremental-full"));
1782 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1783 // can be calculated from the PLT index, adjusting for the three
1784 // reserved entries at the beginning of the GOT.
1785 plt_index
= plt_offset
/ this->get_plt_entry_size() - 1;
1786 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1789 gsym
->set_plt_offset(plt_offset
);
1791 // Every PLT entry needs a reloc.
1792 this->add_relocation(symtab
, layout
, gsym
, got_offset
);
1794 // Note that we don't need to save the symbol. The contents of the
1795 // PLT are independent of which symbols are used. The symbols only
1796 // appear in the relocations.
1799 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1804 Output_data_plt_x86_64
<size
>::add_local_ifunc_entry(
1805 Symbol_table
* symtab
,
1807 Sized_relobj_file
<size
, false>* relobj
,
1808 unsigned int local_sym_index
)
1810 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1811 ++this->irelative_count_
;
1813 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1815 // Every PLT entry needs a GOT entry which points back to the PLT
1817 this->got_irelative_
->set_current_data_size(got_offset
+ 8);
1819 // Every PLT entry needs a reloc.
1820 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1821 rela
->add_symbolless_local_addend(relobj
, local_sym_index
,
1822 elfcpp::R_X86_64_IRELATIVE
,
1823 this->got_irelative_
, got_offset
, 0);
1828 // Add the relocation for a PLT entry.
1832 Output_data_plt_x86_64
<size
>::add_relocation(Symbol_table
* symtab
,
1835 unsigned int got_offset
)
1837 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1838 && gsym
->can_use_relative_reloc(false))
1840 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1841 rela
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
1842 this->got_irelative_
, got_offset
, 0);
1846 gsym
->set_needs_dynsym_entry();
1847 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
1852 // Return where the TLSDESC relocations should go, creating it if
1853 // necessary. These follow the JUMP_SLOT relocations.
1856 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1857 Output_data_plt_x86_64
<size
>::rela_tlsdesc(Layout
* layout
)
1859 if (this->tlsdesc_rel_
== NULL
)
1861 this->tlsdesc_rel_
= new Reloc_section(false);
1862 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1863 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
1864 ORDER_DYNAMIC_PLT_RELOCS
, false);
1865 gold_assert(this->tlsdesc_rel_
->output_section()
1866 == this->rel_
->output_section());
1868 return this->tlsdesc_rel_
;
1871 // Return where the IRELATIVE relocations should go in the PLT. These
1872 // follow the JUMP_SLOT and the TLSDESC relocations.
1875 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1876 Output_data_plt_x86_64
<size
>::rela_irelative(Symbol_table
* symtab
,
1879 if (this->irelative_rel_
== NULL
)
1881 // Make sure we have a place for the TLSDESC relocations, in
1882 // case we see any later on.
1883 this->rela_tlsdesc(layout
);
1884 this->irelative_rel_
= new Reloc_section(false);
1885 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1886 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1887 ORDER_DYNAMIC_PLT_RELOCS
, false);
1888 gold_assert(this->irelative_rel_
->output_section()
1889 == this->rel_
->output_section());
1891 if (parameters
->doing_static_link())
1893 // A statically linked executable will only have a .rela.plt
1894 // section to hold R_X86_64_IRELATIVE relocs for
1895 // STT_GNU_IFUNC symbols. The library will use these
1896 // symbols to locate the IRELATIVE relocs at program startup
1898 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
1899 Symbol_table::PREDEFINED
,
1900 this->irelative_rel_
, 0, 0,
1901 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1902 elfcpp::STV_HIDDEN
, 0, false, true);
1903 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
1904 Symbol_table::PREDEFINED
,
1905 this->irelative_rel_
, 0, 0,
1906 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1907 elfcpp::STV_HIDDEN
, 0, true, true);
1910 return this->irelative_rel_
;
1913 // Return the PLT address to use for a global symbol.
1917 Output_data_plt_x86_64
<size
>::do_address_for_global(const Symbol
* gsym
)
1919 uint64_t offset
= 0;
1920 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1921 && gsym
->can_use_relative_reloc(false))
1922 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1923 return this->address() + offset
+ gsym
->plt_offset();
1926 // Return the PLT address to use for a local symbol. These are always
1927 // IRELATIVE relocs.
1931 Output_data_plt_x86_64
<size
>::do_address_for_local(const Relobj
* object
,
1934 return (this->address()
1935 + (this->count_
+ 1) * this->get_plt_entry_size()
1936 + object
->local_plt_offset(r_sym
));
1939 // Set the final size.
1942 Output_data_plt_x86_64
<size
>::set_final_data_size()
1944 // Number of regular and IFUNC PLT entries, plus the first entry.
1945 unsigned int count
= this->count_
+ this->irelative_count_
+ 1;
1946 // Count the TLSDESC entry, if present.
1947 if (this->has_tlsdesc_entry())
1949 this->set_data_size(count
* this->get_plt_entry_size());
1952 // The first entry in the PLT for an executable.
1956 Output_data_plt_x86_64_standard
<size
>::first_plt_entry
[plt_entry_size
] =
1958 // From AMD64 ABI Draft 0.98, page 76
1959 0xff, 0x35, // pushq contents of memory address
1960 0, 0, 0, 0, // replaced with address of .got + 8
1961 0xff, 0x25, // jmp indirect
1962 0, 0, 0, 0, // replaced with address of .got + 16
1963 0x90, 0x90, 0x90, 0x90 // noop (x4)
1968 Output_data_plt_x86_64_standard
<size
>::do_fill_first_plt_entry(
1970 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1971 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
1973 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1974 // We do a jmp relative to the PC at the end of this instruction.
1975 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1977 - (plt_address
+ 6)));
1978 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
1980 - (plt_address
+ 12)));
1983 // Subsequent entries in the PLT for an executable.
1987 Output_data_plt_x86_64_standard
<size
>::plt_entry
[plt_entry_size
] =
1989 // From AMD64 ABI Draft 0.98, page 76
1990 0xff, 0x25, // jmpq indirect
1991 0, 0, 0, 0, // replaced with address of symbol in .got
1992 0x68, // pushq immediate
1993 0, 0, 0, 0, // replaced with offset into relocation table
1994 0xe9, // jmpq relative
1995 0, 0, 0, 0 // replaced with offset to start of .plt
2000 Output_data_plt_x86_64_standard
<size
>::do_fill_plt_entry(
2002 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2003 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2004 unsigned int got_offset
,
2005 unsigned int plt_offset
,
2006 unsigned int plt_index
)
2008 // Check PC-relative offset overflow in PLT entry.
2009 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
2010 - (plt_address
+ plt_offset
+ 6));
2011 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
2012 gold_error(_("PC-relative offset overflow in PLT entry %d"),
2015 memcpy(pov
, plt_entry
, plt_entry_size
);
2016 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2017 plt_got_pcrel_offset
);
2019 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
2020 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
2021 - (plt_offset
+ plt_entry_size
));
2026 // The reserved TLSDESC entry in the PLT for an executable.
2030 Output_data_plt_x86_64_standard
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
2032 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2033 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2034 0xff, 0x35, // pushq x(%rip)
2035 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2036 0xff, 0x25, // jmpq *y(%rip)
2037 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2044 Output_data_plt_x86_64_standard
<size
>::do_fill_tlsdesc_entry(
2046 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2047 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2048 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
2049 unsigned int tlsdesc_got_offset
,
2050 unsigned int plt_offset
)
2052 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
2053 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2055 - (plt_address
+ plt_offset
2057 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
2059 + tlsdesc_got_offset
2060 - (plt_address
+ plt_offset
2064 // Return the APLT address to use for a global symbol (for -z bndplt).
2067 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol
* gsym
)
2069 uint64_t offset
= this->aplt_offset_
;
2070 // Convert the PLT offset into an APLT offset.
2071 unsigned int plt_offset
= gsym
->plt_offset();
2072 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2073 && gsym
->can_use_relative_reloc(false))
2074 offset
+= this->regular_count() * aplt_entry_size
;
2076 plt_offset
-= plt_entry_size
;
2077 plt_offset
= plt_offset
/ (plt_entry_size
/ aplt_entry_size
);
2078 return this->address() + offset
+ plt_offset
;
2081 // Return the PLT address to use for a local symbol. These are always
2082 // IRELATIVE relocs.
2085 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj
* object
,
2088 // Convert the PLT offset into an APLT offset.
2089 unsigned int plt_offset
= ((object
->local_plt_offset(r_sym
) - plt_entry_size
)
2090 / (plt_entry_size
/ aplt_entry_size
));
2091 return (this->address()
2092 + this->aplt_offset_
2093 + this->regular_count() * aplt_entry_size
2097 // Set the final size.
2099 Output_data_plt_x86_64_bnd::set_final_data_size()
2101 // Number of regular and IFUNC PLT entries.
2102 unsigned int count
= this->entry_count();
2103 // Count the first entry and the TLSDESC entry, if present.
2104 unsigned int extra
= this->has_tlsdesc_entry() ? 2 : 1;
2105 unsigned int plt_size
= (count
+ extra
) * plt_entry_size
;
2106 // Offset of the APLT.
2107 this->aplt_offset_
= plt_size
;
2108 // Size of the APLT.
2109 plt_size
+= count
* aplt_entry_size
;
2110 this->set_data_size(plt_size
);
2113 // The first entry in the BND PLT.
2116 Output_data_plt_x86_64_bnd::first_plt_entry
[plt_entry_size
] =
2118 // From AMD64 ABI Draft 0.98, page 76
2119 0xff, 0x35, // pushq contents of memory address
2120 0, 0, 0, 0, // replaced with address of .got + 8
2121 0xf2, 0xff, 0x25, // bnd jmp indirect
2122 0, 0, 0, 0, // replaced with address of .got + 16
2123 0x0f, 0x1f, 0x00 // nop
2127 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
2129 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
2130 elfcpp::Elf_types
<64>::Elf_Addr plt_address
)
2132 memcpy(pov
, first_plt_entry
, plt_entry_size
);
2133 // We do a jmp relative to the PC at the end of this instruction.
2134 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2136 - (plt_address
+ 6)));
2137 elfcpp::Swap
<32, false>::writeval(pov
+ 9,
2139 - (plt_address
+ 13)));
2142 // Subsequent entries in the BND PLT.
2145 Output_data_plt_x86_64_bnd::plt_entry
[plt_entry_size
] =
2147 // From AMD64 ABI Draft 0.99.8, page 139
2148 0x68, // pushq immediate
2149 0, 0, 0, 0, // replaced with offset into relocation table
2150 0xf2, 0xe9, // bnd jmpq relative
2151 0, 0, 0, 0, // replaced with offset to start of .plt
2152 0x0f, 0x1f, 0x44, 0, 0 // nop
2155 // Entries in the BND Additional PLT.
2158 Output_data_plt_x86_64_bnd::aplt_entry
[aplt_entry_size
] =
2160 // From AMD64 ABI Draft 0.99.8, page 139
2161 0xf2, 0xff, 0x25, // bnd jmpq indirect
2162 0, 0, 0, 0, // replaced with address of symbol in .got
2167 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
2169 elfcpp::Elf_types
<64>::Elf_Addr
,
2170 elfcpp::Elf_types
<64>::Elf_Addr
,
2172 unsigned int plt_offset
,
2173 unsigned int plt_index
)
2175 memcpy(pov
, plt_entry
, plt_entry_size
);
2176 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 1, plt_index
);
2177 elfcpp::Swap
<32, false>::writeval(pov
+ 7, -(plt_offset
+ 11));
2182 Output_data_plt_x86_64_bnd::fill_aplt_entry(
2184 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
2185 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
2186 unsigned int got_offset
,
2187 unsigned int plt_offset
,
2188 unsigned int plt_index
)
2190 // Check PC-relative offset overflow in PLT entry.
2191 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
2192 - (plt_address
+ plt_offset
+ 7));
2193 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
2194 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2197 memcpy(pov
, aplt_entry
, aplt_entry_size
);
2198 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3, plt_got_pcrel_offset
);
2201 // The reserved TLSDESC entry in the PLT for an executable.
2204 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry
[plt_entry_size
] =
2206 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2207 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2208 0xff, 0x35, // pushq x(%rip)
2209 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2210 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2211 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2212 0x0f, 0x1f, 0 // nop
2216 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
2218 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
2219 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
2220 elfcpp::Elf_types
<64>::Elf_Addr got_base
,
2221 unsigned int tlsdesc_got_offset
,
2222 unsigned int plt_offset
)
2224 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
2225 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2227 - (plt_address
+ plt_offset
2229 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
2231 + tlsdesc_got_offset
2232 - (plt_address
+ plt_offset
2236 // Return the APLT address to use for a global symbol (for IBT).
2240 Output_data_plt_x86_64_ibt
<size
>::do_address_for_global(const Symbol
* gsym
)
2242 uint64_t offset
= this->aplt_offset_
;
2243 // Convert the PLT offset into an APLT offset.
2244 unsigned int plt_offset
= gsym
->plt_offset();
2245 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2246 && gsym
->can_use_relative_reloc(false))
2247 offset
+= this->regular_count() * aplt_entry_size
;
2249 plt_offset
-= plt_entry_size
;
2250 plt_offset
= plt_offset
/ (plt_entry_size
/ aplt_entry_size
);
2251 return this->address() + offset
+ plt_offset
;
2254 // Return the PLT address to use for a local symbol. These are always
2255 // IRELATIVE relocs.
2259 Output_data_plt_x86_64_ibt
<size
>::do_address_for_local(const Relobj
* object
,
2262 // Convert the PLT offset into an APLT offset.
2263 unsigned int plt_offset
= ((object
->local_plt_offset(r_sym
) - plt_entry_size
)
2264 / (plt_entry_size
/ aplt_entry_size
));
2265 return (this->address()
2266 + this->aplt_offset_
2267 + this->regular_count() * aplt_entry_size
2271 // Set the final size.
2275 Output_data_plt_x86_64_ibt
<size
>::set_final_data_size()
2277 // Number of regular and IFUNC PLT entries.
2278 unsigned int count
= this->entry_count();
2279 // Count the first entry and the TLSDESC entry, if present.
2280 unsigned int extra
= this->has_tlsdesc_entry() ? 2 : 1;
2281 unsigned int plt_size
= (count
+ extra
) * plt_entry_size
;
2282 // Offset of the APLT.
2283 this->aplt_offset_
= plt_size
;
2284 // Size of the APLT.
2285 plt_size
+= count
* aplt_entry_size
;
2286 this->set_data_size(plt_size
);
2289 // The first entry in the IBT PLT.
2293 Output_data_plt_x86_64_ibt
<32>::first_plt_entry
[plt_entry_size
] =
2295 // MPX isn't supported for x32, so we don't need the BND prefix.
2296 // From AMD64 ABI Draft 0.98, page 76
2297 0xff, 0x35, // pushq contents of memory address
2298 0, 0, 0, 0, // replaced with address of .got + 8
2299 0xff, 0x25, // jmp indirect
2300 0, 0, 0, 0, // replaced with address of .got + 16
2301 0x90, 0x90, 0x90, 0x90 // noop (x4)
2306 Output_data_plt_x86_64_ibt
<64>::first_plt_entry
[plt_entry_size
] =
2308 // Use the BND prefix so that IBT is compatible with MPX.
2309 0xff, 0x35, // pushq contents of memory address
2310 0, 0, 0, 0, // replaced with address of .got + 8
2311 0xf2, 0xff, 0x25, // bnd jmp indirect
2312 0, 0, 0, 0, // replaced with address of .got + 16
2313 0x0f, 0x1f, 0x00 // nop
2318 Output_data_plt_x86_64_ibt
<size
>::do_fill_first_plt_entry(
2320 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2321 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
2323 // Offsets to the addresses needing relocation.
2324 const unsigned int roff1
= 2;
2325 const unsigned int roff2
= (size
== 32) ? 8 : 9;
2327 memcpy(pov
, first_plt_entry
, plt_entry_size
);
2328 // We do a jmp relative to the PC at the end of this instruction.
2329 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ roff1
,
2331 - (plt_address
+ roff1
+ 4)));
2332 elfcpp::Swap
<32, false>::writeval(pov
+ roff2
,
2334 - (plt_address
+ roff2
+ 4)));
2337 // Subsequent entries in the IBT PLT.
2341 Output_data_plt_x86_64_ibt
<32>::plt_entry
[plt_entry_size
] =
2343 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2344 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2345 0x68, // pushq immediate
2346 0, 0, 0, 0, // replaced with offset into relocation table
2347 0xe9, // jmpq relative
2348 0, 0, 0, 0, // replaced with offset to start of .plt
2354 Output_data_plt_x86_64_ibt
<64>::plt_entry
[plt_entry_size
] =
2356 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2357 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2358 0x68, // pushq immediate
2359 0, 0, 0, 0, // replaced with offset into relocation table
2360 0xf2, 0xe9, // bnd jmpq relative
2361 0, 0, 0, 0, // replaced with offset to start of .plt
2365 // Entries in the IBT Additional PLT.
2369 Output_data_plt_x86_64_ibt
<32>::aplt_entry
[aplt_entry_size
] =
2371 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2372 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2373 0xff, 0x25, // jmpq indirect
2374 0, 0, 0, 0, // replaced with address of symbol in .got
2375 0x0f, 0x1f, 0x04, 0x00, // nop
2381 Output_data_plt_x86_64_ibt
<64>::aplt_entry
[aplt_entry_size
] =
2383 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2384 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2385 0xf2, 0xff, 0x25, // bnd jmpq indirect
2386 0, 0, 0, 0, // replaced with address of symbol in .got
2387 0x0f, 0x1f, 0x04, 0x00, // nop
2393 Output_data_plt_x86_64_ibt
<size
>::do_fill_plt_entry(
2395 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
2396 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
2398 unsigned int plt_offset
,
2399 unsigned int plt_index
)
2401 // Offsets to the addresses needing relocation.
2402 const unsigned int roff1
= 5;
2403 const unsigned int roff2
= (size
== 32) ? 10 : 11;
2405 memcpy(pov
, plt_entry
, plt_entry_size
);
2406 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ roff1
, plt_index
);
2407 elfcpp::Swap
<32, false>::writeval(pov
+ roff2
, -(plt_offset
+ roff2
+ 4));
2413 Output_data_plt_x86_64_ibt
<size
>::fill_aplt_entry(
2415 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2416 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2417 unsigned int got_offset
,
2418 unsigned int plt_offset
,
2419 unsigned int plt_index
)
2421 // Offset to the address needing relocation.
2422 const unsigned int roff
= (size
== 32) ? 6 : 7;
2424 // Check PC-relative offset overflow in PLT entry.
2425 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
2426 - (plt_address
+ plt_offset
+ roff
+ 4));
2427 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
2428 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2431 memcpy(pov
, aplt_entry
, aplt_entry_size
);
2432 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ roff
, plt_got_pcrel_offset
);
2435 // The reserved TLSDESC entry in the IBT PLT for an executable.
2439 Output_data_plt_x86_64_ibt
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
2441 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2442 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2443 0xff, 0x35, // pushq x(%rip)
2444 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2445 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2446 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2447 0x0f, 0x1f, 0 // nop
2452 Output_data_plt_x86_64_ibt
<size
>::do_fill_tlsdesc_entry(
2454 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2455 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2456 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
2457 unsigned int tlsdesc_got_offset
,
2458 unsigned int plt_offset
)
2460 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
2461 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2463 - (plt_address
+ plt_offset
2465 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
2467 + tlsdesc_got_offset
2468 - (plt_address
+ plt_offset
2472 // The .eh_frame unwind information for the PLT.
2476 Output_data_plt_x86_64
<size
>::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
2479 'z', // Augmentation: augmentation size included.
2480 'R', // Augmentation: FDE encoding included.
2481 '\0', // End of augmentation string.
2482 1, // Code alignment factor.
2483 0x78, // Data alignment factor.
2484 16, // Return address column.
2485 1, // Augmentation size.
2486 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
2487 | elfcpp::DW_EH_PE_sdata4
),
2488 elfcpp::DW_CFA_def_cfa
, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
2489 elfcpp::DW_CFA_offset
+ 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2490 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
2496 Output_data_plt_x86_64_standard
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2498 0, 0, 0, 0, // Replaced with offset to .plt.
2499 0, 0, 0, 0, // Replaced with size of .plt.
2500 0, // Augmentation size.
2501 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2502 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2503 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2504 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2505 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2506 11, // Block length.
2507 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2508 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2509 elfcpp::DW_OP_lit15
, // Push 0xf.
2510 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2511 elfcpp::DW_OP_lit11
, // Push 0xb.
2512 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 0xb)
2513 elfcpp::DW_OP_lit3
, // Push 3.
2514 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 0xb) << 3)
2515 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2516 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2522 // The .eh_frame unwind information for the BND PLT.
2524 Output_data_plt_x86_64_bnd::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2526 0, 0, 0, 0, // Replaced with offset to .plt.
2527 0, 0, 0, 0, // Replaced with size of .plt.
2528 0, // Augmentation size.
2529 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2530 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2531 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2532 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2533 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2534 11, // Block length.
2535 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2536 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2537 elfcpp::DW_OP_lit15
, // Push 0xf.
2538 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2539 elfcpp::DW_OP_lit5
, // Push 5.
2540 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 5)
2541 elfcpp::DW_OP_lit3
, // Push 3.
2542 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 5) << 3)
2543 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
2544 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2550 // The .eh_frame unwind information for the BND PLT.
2553 Output_data_plt_x86_64_ibt
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2555 0, 0, 0, 0, // Replaced with offset to .plt.
2556 0, 0, 0, 0, // Replaced with size of .plt.
2557 0, // Augmentation size.
2558 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2559 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2560 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2561 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2562 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2563 11, // Block length.
2564 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2565 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2566 elfcpp::DW_OP_lit15
, // Push 0xf.
2567 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2568 elfcpp::DW_OP_lit9
, // Push 9.
2569 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 9)
2570 elfcpp::DW_OP_lit3
, // Push 3.
2571 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 9) << 3)
2572 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=9)<<3)+%rsp+8
2573 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2579 // Write out the PLT. This uses the hand-coded instructions above,
2580 // and adjusts them as needed. This is specified by the AMD64 ABI.
2584 Output_data_plt_x86_64
<size
>::do_write(Output_file
* of
)
2586 const off_t offset
= this->offset();
2587 const section_size_type oview_size
=
2588 convert_to_section_size_type(this->data_size());
2589 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2591 const off_t got_file_offset
= this->got_plt_
->offset();
2592 gold_assert(parameters
->incremental_update()
2593 || (got_file_offset
+ this->got_plt_
->data_size()
2594 == this->got_irelative_
->offset()));
2595 const section_size_type got_size
=
2596 convert_to_section_size_type(this->got_plt_
->data_size()
2597 + this->got_irelative_
->data_size());
2598 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2601 unsigned char* pov
= oview
;
2603 // The base address of the .plt section.
2604 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
= this->address();
2605 // The base address of the .got section.
2606 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
= this->got_
->address();
2607 // The base address of the PLT portion of the .got section,
2608 // which is where the GOT pointer will point, and where the
2609 // three reserved GOT entries are located.
2610 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
2611 = this->got_plt_
->address();
2613 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2614 pov
+= this->get_plt_entry_size();
2616 // The first three entries in the GOT are reserved, and are written
2617 // by Output_data_got_plt_x86_64::do_write.
2618 unsigned char* got_pov
= got_view
+ 24;
2620 unsigned int plt_offset
= this->get_plt_entry_size();
2621 unsigned int got_offset
= 24;
2622 const unsigned int count
= this->count_
+ this->irelative_count_
;
2623 for (unsigned int plt_index
= 0;
2626 pov
+= this->get_plt_entry_size(),
2628 plt_offset
+= this->get_plt_entry_size(),
2631 // Set and adjust the PLT entry itself.
2632 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2633 got_address
, plt_address
,
2634 got_offset
, plt_offset
,
2637 // Set the entry in the GOT.
2638 elfcpp::Swap
<64, false>::writeval(got_pov
,
2639 plt_address
+ plt_offset
+ lazy_offset
);
2642 if (this->has_tlsdesc_entry())
2644 // Set and adjust the reserved TLSDESC PLT entry.
2645 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2646 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2647 tlsdesc_got_offset
, plt_offset
);
2648 pov
+= this->get_plt_entry_size();
2651 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2652 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2654 of
->write_output_view(offset
, oview_size
, oview
);
2655 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2658 // Write out the BND PLT.
2661 Output_data_plt_x86_64_bnd::do_write(Output_file
* of
)
2663 const off_t offset
= this->offset();
2664 const section_size_type oview_size
=
2665 convert_to_section_size_type(this->data_size());
2666 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2668 Output_data_got
<64, false>* got
= this->got();
2669 Output_data_got_plt_x86_64
* got_plt
= this->got_plt();
2670 Output_data_space
* got_irelative
= this->got_irelative();
2672 const off_t got_file_offset
= got_plt
->offset();
2673 gold_assert(parameters
->incremental_update()
2674 || (got_file_offset
+ got_plt
->data_size()
2675 == got_irelative
->offset()));
2676 const section_size_type got_size
=
2677 convert_to_section_size_type(got_plt
->data_size()
2678 + got_irelative
->data_size());
2679 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2682 unsigned char* pov
= oview
;
2684 // The base address of the .plt section.
2685 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
2686 // The base address of the .got section.
2687 elfcpp::Elf_types
<64>::Elf_Addr got_base
= got
->address();
2688 // The base address of the PLT portion of the .got section,
2689 // which is where the GOT pointer will point, and where the
2690 // three reserved GOT entries are located.
2691 elfcpp::Elf_types
<64>::Elf_Addr got_address
= got_plt
->address();
2693 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2694 pov
+= plt_entry_size
;
2696 // The first three entries in the GOT are reserved, and are written
2697 // by Output_data_got_plt_x86_64::do_write.
2698 unsigned char* got_pov
= got_view
+ 24;
2700 unsigned int plt_offset
= plt_entry_size
;
2701 unsigned int got_offset
= 24;
2702 const unsigned int count
= this->entry_count();
2703 for (unsigned int plt_index
= 0;
2706 pov
+= plt_entry_size
,
2708 plt_offset
+= plt_entry_size
,
2711 // Set and adjust the PLT entry itself.
2712 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2713 got_address
, plt_address
,
2714 got_offset
, plt_offset
,
2717 // Set the entry in the GOT.
2718 elfcpp::Swap
<64, false>::writeval(got_pov
,
2719 plt_address
+ plt_offset
+ lazy_offset
);
2722 if (this->has_tlsdesc_entry())
2724 // Set and adjust the reserved TLSDESC PLT entry.
2725 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2726 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2727 tlsdesc_got_offset
, plt_offset
);
2728 pov
+= this->get_plt_entry_size();
2731 // Write the additional PLT.
2733 for (unsigned int plt_index
= 0;
2736 pov
+= aplt_entry_size
,
2737 plt_offset
+= aplt_entry_size
,
2740 // Set and adjust the APLT entry.
2741 this->fill_aplt_entry(pov
, got_address
, plt_address
, got_offset
,
2742 plt_offset
, plt_index
);
2745 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2746 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2748 of
->write_output_view(offset
, oview_size
, oview
);
2749 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2752 // Write out the IBT PLT.
2756 Output_data_plt_x86_64_ibt
<size
>::do_write(Output_file
* of
)
2758 const off_t offset
= this->offset();
2759 const section_size_type oview_size
=
2760 convert_to_section_size_type(this->data_size());
2761 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2763 Output_data_got
<64, false>* got
= this->got();
2764 Output_data_got_plt_x86_64
* got_plt
= this->got_plt();
2765 Output_data_space
* got_irelative
= this->got_irelative();
2767 const off_t got_file_offset
= got_plt
->offset();
2768 gold_assert(parameters
->incremental_update()
2769 || (got_file_offset
+ got_plt
->data_size()
2770 == got_irelative
->offset()));
2771 const section_size_type got_size
=
2772 convert_to_section_size_type(got_plt
->data_size()
2773 + got_irelative
->data_size());
2774 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2777 unsigned char* pov
= oview
;
2779 // The base address of the .plt section.
2780 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
2781 // The base address of the .got section.
2782 elfcpp::Elf_types
<64>::Elf_Addr got_base
= got
->address();
2783 // The base address of the PLT portion of the .got section,
2784 // which is where the GOT pointer will point, and where the
2785 // three reserved GOT entries are located.
2786 elfcpp::Elf_types
<64>::Elf_Addr got_address
= got_plt
->address();
2788 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2789 pov
+= plt_entry_size
;
2791 // The first three entries in the GOT are reserved, and are written
2792 // by Output_data_got_plt_x86_64::do_write.
2793 unsigned char* got_pov
= got_view
+ 24;
2795 unsigned int plt_offset
= plt_entry_size
;
2796 unsigned int got_offset
= 24;
2797 const unsigned int count
= this->entry_count();
2798 for (unsigned int plt_index
= 0;
2801 pov
+= plt_entry_size
,
2803 plt_offset
+= plt_entry_size
,
2806 // Set and adjust the PLT entry itself.
2807 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2808 got_address
, plt_address
,
2809 got_offset
, plt_offset
,
2812 // Set the entry in the GOT.
2813 elfcpp::Swap
<64, false>::writeval(got_pov
,
2814 plt_address
+ plt_offset
+ lazy_offset
);
2817 if (this->has_tlsdesc_entry())
2819 // Set and adjust the reserved TLSDESC PLT entry.
2820 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2821 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2822 tlsdesc_got_offset
, plt_offset
);
2823 pov
+= this->get_plt_entry_size();
2826 // Write the additional PLT.
2828 for (unsigned int plt_index
= 0;
2831 pov
+= aplt_entry_size
,
2832 plt_offset
+= aplt_entry_size
,
2835 // Set and adjust the APLT entry.
2836 this->fill_aplt_entry(pov
, got_address
, plt_address
, got_offset
,
2837 plt_offset
, plt_index
);
2840 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2841 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2843 of
->write_output_view(offset
, oview_size
, oview
);
2844 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2847 // Create the PLT section.
2851 Target_x86_64
<size
>::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
2853 if (this->plt_
== NULL
)
2855 // Create the GOT sections first.
2856 this->got_section(symtab
, layout
);
2858 this->plt_
= this->make_data_plt(layout
, this->got_
, this->got_plt_
,
2859 this->got_irelative_
);
2861 // Add unwind information if requested.
2862 if (parameters
->options().ld_generated_unwind_info())
2863 this->plt_
->add_eh_frame(layout
);
2865 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
2867 | elfcpp::SHF_EXECINSTR
),
2868 this->plt_
, ORDER_PLT
, false);
2870 // Make the sh_info field of .rela.plt point to .plt.
2871 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
2872 rela_plt_os
->set_info_section(this->plt_
->output_section());
2877 Output_data_plt_x86_64
<32>*
2878 Target_x86_64
<32>::do_make_data_plt(Layout
* layout
,
2879 Output_data_got
<64, false>* got
,
2880 Output_data_got_plt_x86_64
* got_plt
,
2881 Output_data_space
* got_irelative
)
2883 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2884 return new Output_data_plt_x86_64_ibt
<32>(layout
, got
, got_plt
,
2886 return new Output_data_plt_x86_64_standard
<32>(layout
, got
, got_plt
,
2891 Output_data_plt_x86_64
<64>*
2892 Target_x86_64
<64>::do_make_data_plt(Layout
* layout
,
2893 Output_data_got
<64, false>* got
,
2894 Output_data_got_plt_x86_64
* got_plt
,
2895 Output_data_space
* got_irelative
)
2897 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2898 return new Output_data_plt_x86_64_ibt
<64>(layout
, got
, got_plt
,
2900 else if (parameters
->options().bndplt())
2901 return new Output_data_plt_x86_64_bnd(layout
, got
, got_plt
,
2904 return new Output_data_plt_x86_64_standard
<64>(layout
, got
, got_plt
,
2909 Output_data_plt_x86_64
<32>*
2910 Target_x86_64
<32>::do_make_data_plt(Layout
* layout
,
2911 Output_data_got
<64, false>* got
,
2912 Output_data_got_plt_x86_64
* got_plt
,
2913 Output_data_space
* got_irelative
,
2914 unsigned int plt_count
)
2916 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2917 return new Output_data_plt_x86_64_ibt
<32>(layout
, got
, got_plt
,
2918 got_irelative
, plt_count
);
2919 return new Output_data_plt_x86_64_standard
<32>(layout
, got
, got_plt
,
2920 got_irelative
, plt_count
);
2924 Output_data_plt_x86_64
<64>*
2925 Target_x86_64
<64>::do_make_data_plt(Layout
* layout
,
2926 Output_data_got
<64, false>* got
,
2927 Output_data_got_plt_x86_64
* got_plt
,
2928 Output_data_space
* got_irelative
,
2929 unsigned int plt_count
)
2931 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2932 return new Output_data_plt_x86_64_ibt
<64>(layout
, got
, got_plt
,
2933 got_irelative
, plt_count
);
2934 else if (parameters
->options().bndplt())
2935 return new Output_data_plt_x86_64_bnd(layout
, got
, got_plt
,
2936 got_irelative
, plt_count
);
2938 return new Output_data_plt_x86_64_standard
<64>(layout
, got
, got_plt
,
2943 // Return the section for TLSDESC relocations.
2946 typename Target_x86_64
<size
>::Reloc_section
*
2947 Target_x86_64
<size
>::rela_tlsdesc_section(Layout
* layout
) const
2949 return this->plt_section()->rela_tlsdesc(layout
);
2952 // Create a PLT entry for a global symbol.
2956 Target_x86_64
<size
>::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
2959 if (gsym
->has_plt_offset())
2962 if (this->plt_
== NULL
)
2963 this->make_plt_section(symtab
, layout
);
2965 this->plt_
->add_entry(symtab
, layout
, gsym
);
2968 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
2972 Target_x86_64
<size
>::make_local_ifunc_plt_entry(
2973 Symbol_table
* symtab
, Layout
* layout
,
2974 Sized_relobj_file
<size
, false>* relobj
,
2975 unsigned int local_sym_index
)
2977 if (relobj
->local_has_plt_offset(local_sym_index
))
2979 if (this->plt_
== NULL
)
2980 this->make_plt_section(symtab
, layout
);
2981 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
2984 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
2987 // Return the number of entries in the PLT.
2991 Target_x86_64
<size
>::plt_entry_count() const
2993 if (this->plt_
== NULL
)
2995 return this->plt_
->entry_count();
2998 // Return the offset of the first non-reserved PLT entry.
3002 Target_x86_64
<size
>::first_plt_entry_offset() const
3004 if (this->plt_
== NULL
)
3006 return this->plt_
->first_plt_entry_offset();
3009 // Return the size of each PLT entry.
3013 Target_x86_64
<size
>::plt_entry_size() const
3015 if (this->plt_
== NULL
)
3017 return this->plt_
->get_plt_entry_size();
3020 // Create the GOT and PLT sections for an incremental update.
3023 Output_data_got_base
*
3024 Target_x86_64
<size
>::init_got_plt_for_update(Symbol_table
* symtab
,
3026 unsigned int got_count
,
3027 unsigned int plt_count
)
3029 gold_assert(this->got_
== NULL
);
3031 this->got_
= new Output_data_got
<64, false>(got_count
* 8);
3032 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
3034 | elfcpp::SHF_WRITE
),
3035 this->got_
, ORDER_RELRO_LAST
,
3038 // Add the three reserved entries.
3039 this->got_plt_
= new Output_data_got_plt_x86_64(layout
, (plt_count
+ 3) * 8);
3040 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
3042 | elfcpp::SHF_WRITE
),
3043 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
3046 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3047 this->global_offset_table_
=
3048 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
3049 Symbol_table::PREDEFINED
,
3051 0, 0, elfcpp::STT_OBJECT
,
3053 elfcpp::STV_HIDDEN
, 0,
3056 // If there are any TLSDESC relocations, they get GOT entries in
3057 // .got.plt after the jump slot entries.
3058 // FIXME: Get the count for TLSDESC entries.
3059 this->got_tlsdesc_
= new Output_data_got
<64, false>(0);
3060 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
3061 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
3063 ORDER_NON_RELRO_FIRST
, false);
3065 // If there are any IRELATIVE relocations, they get GOT entries in
3066 // .got.plt after the jump slot and TLSDESC entries.
3067 this->got_irelative_
= new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
3068 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
3069 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
3070 this->got_irelative_
,
3071 ORDER_NON_RELRO_FIRST
, false);
3073 // Create the PLT section.
3074 this->plt_
= this->make_data_plt(layout
, this->got_
,
3076 this->got_irelative_
,
3079 // Add unwind information if requested.
3080 if (parameters
->options().ld_generated_unwind_info())
3081 this->plt_
->add_eh_frame(layout
);
3083 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
3084 elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
,
3085 this->plt_
, ORDER_PLT
, false);
3087 // Make the sh_info field of .rela.plt point to .plt.
3088 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
3089 rela_plt_os
->set_info_section(this->plt_
->output_section());
3091 // Create the rela_dyn section.
3092 this->rela_dyn_section(layout
);
3097 // Reserve a GOT entry for a local symbol, and regenerate any
3098 // necessary dynamic relocations.
3102 Target_x86_64
<size
>::reserve_local_got_entry(
3103 unsigned int got_index
,
3104 Sized_relobj
<size
, false>* obj
,
3106 unsigned int got_type
)
3108 unsigned int got_offset
= got_index
* 8;
3109 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
3111 this->got_
->reserve_local(got_index
, obj
, r_sym
, got_type
);
3114 case GOT_TYPE_STANDARD
:
3115 if (parameters
->options().output_is_position_independent())
3116 rela_dyn
->add_local_relative(obj
, r_sym
, elfcpp::R_X86_64_RELATIVE
,
3117 this->got_
, got_offset
, 0, false);
3119 case GOT_TYPE_TLS_OFFSET
:
3120 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_TPOFF64
,
3121 this->got_
, got_offset
, 0);
3123 case GOT_TYPE_TLS_PAIR
:
3124 this->got_
->reserve_slot(got_index
+ 1);
3125 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_DTPMOD64
,
3126 this->got_
, got_offset
, 0);
3128 case GOT_TYPE_TLS_DESC
:
3129 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
3130 // this->got_->reserve_slot(got_index + 1);
3131 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3132 // this->got_, got_offset, 0);
3139 // Reserve a GOT entry for a global symbol, and regenerate any
3140 // necessary dynamic relocations.
3144 Target_x86_64
<size
>::reserve_global_got_entry(unsigned int got_index
,
3146 unsigned int got_type
)
3148 unsigned int got_offset
= got_index
* 8;
3149 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
3151 this->got_
->reserve_global(got_index
, gsym
, got_type
);
3154 case GOT_TYPE_STANDARD
:
3155 if (!gsym
->final_value_is_known())
3157 if (gsym
->is_from_dynobj()
3158 || gsym
->is_undefined()
3159 || gsym
->is_preemptible()
3160 || gsym
->type() == elfcpp::STT_GNU_IFUNC
)
3161 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
,
3162 this->got_
, got_offset
, 0);
3164 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
3165 this->got_
, got_offset
, 0, false);
3168 case GOT_TYPE_TLS_OFFSET
:
3169 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TPOFF64
,
3170 this->got_
, got_offset
, 0, false);
3172 case GOT_TYPE_TLS_PAIR
:
3173 this->got_
->reserve_slot(got_index
+ 1);
3174 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPMOD64
,
3175 this->got_
, got_offset
, 0, false);
3176 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPOFF64
,
3177 this->got_
, got_offset
+ 8, 0, false);
3179 case GOT_TYPE_TLS_DESC
:
3180 this->got_
->reserve_slot(got_index
+ 1);
3181 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TLSDESC
,
3182 this->got_
, got_offset
, 0, false);
3189 // Register an existing PLT entry for a global symbol.
3193 Target_x86_64
<size
>::register_global_plt_entry(Symbol_table
* symtab
,
3195 unsigned int plt_index
,
3198 gold_assert(this->plt_
!= NULL
);
3199 gold_assert(!gsym
->has_plt_offset());
3201 this->plt_
->reserve_slot(plt_index
);
3203 gsym
->set_plt_offset((plt_index
+ 1) * this->plt_entry_size());
3205 unsigned int got_offset
= (plt_index
+ 3) * 8;
3206 this->plt_
->add_relocation(symtab
, layout
, gsym
, got_offset
);
3209 // Force a COPY relocation for a given symbol.
3213 Target_x86_64
<size
>::emit_copy_reloc(
3214 Symbol_table
* symtab
, Symbol
* sym
, Output_section
* os
, off_t offset
)
3216 this->copy_relocs_
.emit_copy_reloc(symtab
,
3217 symtab
->get_sized_symbol
<size
>(sym
),
3220 this->rela_dyn_section(NULL
));
3223 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
3227 Target_x86_64
<size
>::define_tls_base_symbol(Symbol_table
* symtab
,
3230 if (this->tls_base_symbol_defined_
)
3233 Output_segment
* tls_segment
= layout
->tls_segment();
3234 if (tls_segment
!= NULL
)
3236 bool is_exec
= parameters
->options().output_is_executable();
3237 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
3238 Symbol_table::PREDEFINED
,
3242 elfcpp::STV_HIDDEN
, 0,
3244 ? Symbol::SEGMENT_END
3245 : Symbol::SEGMENT_START
),
3248 this->tls_base_symbol_defined_
= true;
3251 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
3255 Target_x86_64
<size
>::reserve_tlsdesc_entries(Symbol_table
* symtab
,
3258 if (this->plt_
== NULL
)
3259 this->make_plt_section(symtab
, layout
);
3261 if (!this->plt_
->has_tlsdesc_entry())
3263 // Allocate the TLSDESC_GOT entry.
3264 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
3265 unsigned int got_offset
= got
->add_constant(0);
3267 // Allocate the TLSDESC_PLT entry.
3268 this->plt_
->reserve_tlsdesc_entry(got_offset
);
3272 // Create a GOT entry for the TLS module index.
3276 Target_x86_64
<size
>::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
3277 Sized_relobj_file
<size
, false>* object
)
3279 if (this->got_mod_index_offset_
== -1U)
3281 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
3282 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
3283 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
3284 unsigned int got_offset
= got
->add_constant(0);
3285 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
3287 got
->add_constant(0);
3288 this->got_mod_index_offset_
= got_offset
;
3290 return this->got_mod_index_offset_
;
3293 // Optimize the TLS relocation type based on what we know about the
3294 // symbol. IS_FINAL is true if the final address of this symbol is
3295 // known at link time.
3298 tls::Tls_optimization
3299 Target_x86_64
<size
>::optimize_tls_reloc(bool is_final
, int r_type
)
3301 // If we are generating a shared library, then we can't do anything
3303 if (parameters
->options().shared())
3304 return tls::TLSOPT_NONE
;
3308 case elfcpp::R_X86_64_TLSGD
:
3309 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3310 case elfcpp::R_X86_64_TLSDESC_CALL
:
3311 // These are General-Dynamic which permits fully general TLS
3312 // access. Since we know that we are generating an executable,
3313 // we can convert this to Initial-Exec. If we also know that
3314 // this is a local symbol, we can further switch to Local-Exec.
3316 return tls::TLSOPT_TO_LE
;
3317 return tls::TLSOPT_TO_IE
;
3319 case elfcpp::R_X86_64_TLSLD
:
3320 // This is Local-Dynamic, which refers to a local symbol in the
3321 // dynamic TLS block. Since we know that we generating an
3322 // executable, we can switch to Local-Exec.
3323 return tls::TLSOPT_TO_LE
;
3325 case elfcpp::R_X86_64_DTPOFF32
:
3326 case elfcpp::R_X86_64_DTPOFF64
:
3327 // Another Local-Dynamic reloc.
3328 return tls::TLSOPT_TO_LE
;
3330 case elfcpp::R_X86_64_GOTTPOFF
:
3331 // These are Initial-Exec relocs which get the thread offset
3332 // from the GOT. If we know that we are linking against the
3333 // local symbol, we can switch to Local-Exec, which links the
3334 // thread offset into the instruction.
3336 return tls::TLSOPT_TO_LE
;
3337 return tls::TLSOPT_NONE
;
3339 case elfcpp::R_X86_64_TPOFF32
:
3340 // When we already have Local-Exec, there is nothing further we
3342 return tls::TLSOPT_NONE
;
3349 // Get the Reference_flags for a particular relocation.
3353 Target_x86_64
<size
>::Scan::get_reference_flags(unsigned int r_type
)
3357 case elfcpp::R_X86_64_NONE
:
3358 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3359 case elfcpp::R_X86_64_GNU_VTENTRY
:
3360 case elfcpp::R_X86_64_GOTPC32
:
3361 case elfcpp::R_X86_64_GOTPC64
:
3362 // No symbol reference.
3365 case elfcpp::R_X86_64_64
:
3366 case elfcpp::R_X86_64_32
:
3367 case elfcpp::R_X86_64_32S
:
3368 case elfcpp::R_X86_64_16
:
3369 case elfcpp::R_X86_64_8
:
3370 return Symbol::ABSOLUTE_REF
;
3372 case elfcpp::R_X86_64_PC64
:
3373 case elfcpp::R_X86_64_PC32
:
3374 case elfcpp::R_X86_64_PC32_BND
:
3375 case elfcpp::R_X86_64_PC16
:
3376 case elfcpp::R_X86_64_PC8
:
3377 case elfcpp::R_X86_64_GOTOFF64
:
3378 return Symbol::RELATIVE_REF
;
3380 case elfcpp::R_X86_64_PLT32
:
3381 case elfcpp::R_X86_64_PLT32_BND
:
3382 case elfcpp::R_X86_64_PLTOFF64
:
3383 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
3385 case elfcpp::R_X86_64_GOT64
:
3386 case elfcpp::R_X86_64_GOT32
:
3387 case elfcpp::R_X86_64_GOTPCREL64
:
3388 case elfcpp::R_X86_64_GOTPCREL
:
3389 case elfcpp::R_X86_64_GOTPCRELX
:
3390 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3391 case elfcpp::R_X86_64_GOTPLT64
:
3393 return Symbol::ABSOLUTE_REF
;
3395 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3396 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3397 case elfcpp::R_X86_64_TLSDESC_CALL
:
3398 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3399 case elfcpp::R_X86_64_DTPOFF32
:
3400 case elfcpp::R_X86_64_DTPOFF64
:
3401 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3402 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3403 return Symbol::TLS_REF
;
3405 case elfcpp::R_X86_64_COPY
:
3406 case elfcpp::R_X86_64_GLOB_DAT
:
3407 case elfcpp::R_X86_64_JUMP_SLOT
:
3408 case elfcpp::R_X86_64_RELATIVE
:
3409 case elfcpp::R_X86_64_IRELATIVE
:
3410 case elfcpp::R_X86_64_TPOFF64
:
3411 case elfcpp::R_X86_64_DTPMOD64
:
3412 case elfcpp::R_X86_64_TLSDESC
:
3413 case elfcpp::R_X86_64_SIZE32
:
3414 case elfcpp::R_X86_64_SIZE64
:
3416 // Not expected. We will give an error later.
3421 // Report an unsupported relocation against a local symbol.
3425 Target_x86_64
<size
>::Scan::unsupported_reloc_local(
3426 Sized_relobj_file
<size
, false>* object
,
3427 unsigned int r_type
)
3429 gold_error(_("%s: unsupported reloc %u against local symbol"),
3430 object
->name().c_str(), r_type
);
3433 // We are about to emit a dynamic relocation of type R_TYPE. If the
3434 // dynamic linker does not support it, issue an error. The GNU linker
3435 // only issues a non-PIC error for an allocated read-only section.
3436 // Here we know the section is allocated, but we don't know that it is
3437 // read-only. But we check for all the relocation types which the
3438 // glibc dynamic linker supports, so it seems appropriate to issue an
3439 // error even if the section is not read-only. If GSYM is not NULL,
3440 // it is the symbol the relocation is against; if it is NULL, the
3441 // relocation is against a local symbol.
3445 Target_x86_64
<size
>::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
,
3450 // These are the relocation types supported by glibc for x86_64
3451 // which should always work.
3452 case elfcpp::R_X86_64_RELATIVE
:
3453 case elfcpp::R_X86_64_IRELATIVE
:
3454 case elfcpp::R_X86_64_GLOB_DAT
:
3455 case elfcpp::R_X86_64_JUMP_SLOT
:
3456 case elfcpp::R_X86_64_DTPMOD64
:
3457 case elfcpp::R_X86_64_DTPOFF64
:
3458 case elfcpp::R_X86_64_TPOFF64
:
3459 case elfcpp::R_X86_64_64
:
3460 case elfcpp::R_X86_64_COPY
:
3463 // glibc supports these reloc types, but they can overflow.
3464 case elfcpp::R_X86_64_PC32
:
3465 case elfcpp::R_X86_64_PC32_BND
:
3466 // A PC relative reference is OK against a local symbol or if
3467 // the symbol is defined locally.
3469 || (!gsym
->is_from_dynobj()
3470 && !gsym
->is_undefined()
3471 && !gsym
->is_preemptible()))
3474 case elfcpp::R_X86_64_32
:
3475 // R_X86_64_32 is OK for x32.
3476 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
3478 if (this->issued_non_pic_error_
)
3480 gold_assert(parameters
->options().output_is_position_independent());
3482 object
->error(_("requires dynamic R_X86_64_32 reloc which may "
3483 "overflow at runtime; recompile with -fPIC"));
3489 case elfcpp::R_X86_64_32
:
3490 r_name
= "R_X86_64_32";
3492 case elfcpp::R_X86_64_PC32
:
3493 r_name
= "R_X86_64_PC32";
3495 case elfcpp::R_X86_64_PC32_BND
:
3496 r_name
= "R_X86_64_PC32_BND";
3502 object
->error(_("requires dynamic %s reloc against '%s' "
3503 "which may overflow at runtime; recompile "
3505 r_name
, gsym
->name());
3507 this->issued_non_pic_error_
= true;
3511 // This prevents us from issuing more than one error per reloc
3512 // section. But we can still wind up issuing more than one
3513 // error per object file.
3514 if (this->issued_non_pic_error_
)
3516 gold_assert(parameters
->options().output_is_position_independent());
3517 object
->error(_("requires unsupported dynamic reloc %u; "
3518 "recompile with -fPIC"),
3520 this->issued_non_pic_error_
= true;
3523 case elfcpp::R_X86_64_NONE
:
3528 // Return whether we need to make a PLT entry for a relocation of the
3529 // given type against a STT_GNU_IFUNC symbol.
3533 Target_x86_64
<size
>::Scan::reloc_needs_plt_for_ifunc(
3534 Sized_relobj_file
<size
, false>* object
,
3535 unsigned int r_type
)
3537 int flags
= Scan::get_reference_flags(r_type
);
3538 if (flags
& Symbol::TLS_REF
)
3539 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
3540 object
->name().c_str(), r_type
);
3544 // Scan a relocation for a local symbol.
3548 Target_x86_64
<size
>::Scan::local(Symbol_table
* symtab
,
3550 Target_x86_64
<size
>* target
,
3551 Sized_relobj_file
<size
, false>* object
,
3552 unsigned int data_shndx
,
3553 Output_section
* output_section
,
3554 const elfcpp::Rela
<size
, false>& reloc
,
3555 unsigned int r_type
,
3556 const elfcpp::Sym
<size
, false>& lsym
,
3562 // A local STT_GNU_IFUNC symbol may require a PLT entry.
3563 bool is_ifunc
= lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
;
3564 if (is_ifunc
&& this->reloc_needs_plt_for_ifunc(object
, r_type
))
3566 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3567 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
3572 case elfcpp::R_X86_64_NONE
:
3573 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3574 case elfcpp::R_X86_64_GNU_VTENTRY
:
3577 case elfcpp::R_X86_64_64
:
3578 // If building a shared library (or a position-independent
3579 // executable), we need to create a dynamic relocation for this
3580 // location. The relocation applied at link time will apply the
3581 // link-time value, so we flag the location with an
3582 // R_X86_64_RELATIVE relocation so the dynamic loader can
3583 // relocate it easily.
3584 if (parameters
->options().output_is_position_independent())
3586 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3587 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3588 rela_dyn
->add_local_relative(object
, r_sym
,
3590 ? elfcpp::R_X86_64_RELATIVE64
3591 : elfcpp::R_X86_64_RELATIVE
),
3592 output_section
, data_shndx
,
3593 reloc
.get_r_offset(),
3594 reloc
.get_r_addend(), is_ifunc
);
3598 case elfcpp::R_X86_64_32
:
3599 case elfcpp::R_X86_64_32S
:
3600 case elfcpp::R_X86_64_16
:
3601 case elfcpp::R_X86_64_8
:
3602 // If building a shared library (or a position-independent
3603 // executable), we need to create a dynamic relocation for this
3604 // location. We can't use an R_X86_64_RELATIVE relocation
3605 // because that is always a 64-bit relocation.
3606 if (parameters
->options().output_is_position_independent())
3608 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
3609 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
3611 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3612 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3613 rela_dyn
->add_local_relative(object
, r_sym
,
3614 elfcpp::R_X86_64_RELATIVE
,
3615 output_section
, data_shndx
,
3616 reloc
.get_r_offset(),
3617 reloc
.get_r_addend(), is_ifunc
);
3621 this->check_non_pic(object
, r_type
, NULL
);
3623 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3624 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3625 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
3626 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
3627 data_shndx
, reloc
.get_r_offset(),
3628 reloc
.get_r_addend());
3631 gold_assert(lsym
.get_st_value() == 0);
3632 unsigned int shndx
= lsym
.get_st_shndx();
3634 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
3637 object
->error(_("section symbol %u has bad shndx %u"),
3640 rela_dyn
->add_local_section(object
, shndx
,
3641 r_type
, output_section
,
3642 data_shndx
, reloc
.get_r_offset(),
3643 reloc
.get_r_addend());
3648 case elfcpp::R_X86_64_PC64
:
3649 case elfcpp::R_X86_64_PC32
:
3650 case elfcpp::R_X86_64_PC32_BND
:
3651 case elfcpp::R_X86_64_PC16
:
3652 case elfcpp::R_X86_64_PC8
:
3655 case elfcpp::R_X86_64_PLT32
:
3656 case elfcpp::R_X86_64_PLT32_BND
:
3657 // Since we know this is a local symbol, we can handle this as a
3661 case elfcpp::R_X86_64_GOTPC32
:
3662 case elfcpp::R_X86_64_GOTOFF64
:
3663 case elfcpp::R_X86_64_GOTPC64
:
3664 case elfcpp::R_X86_64_PLTOFF64
:
3665 // We need a GOT section.
3666 target
->got_section(symtab
, layout
);
3667 // For PLTOFF64, we'd normally want a PLT section, but since we
3668 // know this is a local symbol, no PLT is needed.
3671 case elfcpp::R_X86_64_GOT64
:
3672 case elfcpp::R_X86_64_GOT32
:
3673 case elfcpp::R_X86_64_GOTPCREL64
:
3674 case elfcpp::R_X86_64_GOTPCREL
:
3675 case elfcpp::R_X86_64_GOTPCRELX
:
3676 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3677 case elfcpp::R_X86_64_GOTPLT64
:
3679 // The symbol requires a GOT section.
3680 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
3682 // If the relocation symbol isn't IFUNC,
3683 // and is local, then we will convert
3684 // mov foo@GOTPCREL(%rip), %reg
3685 // to lea foo(%rip), %reg.
3686 // in Relocate::relocate.
3687 if (!parameters
->incremental()
3688 && (r_type
== elfcpp::R_X86_64_GOTPCREL
3689 || r_type
== elfcpp::R_X86_64_GOTPCRELX
3690 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
3691 && reloc
.get_r_offset() >= 2
3694 section_size_type stype
;
3695 const unsigned char* view
= object
->section_contents(data_shndx
,
3697 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
3701 // The symbol requires a GOT entry.
3702 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3704 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
3705 // lets function pointers compare correctly with shared
3706 // libraries. Otherwise we would need an IRELATIVE reloc.
3709 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
3711 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
3714 // If we are generating a shared object, we need to add a
3715 // dynamic relocation for this symbol's GOT entry.
3716 if (parameters
->options().output_is_position_independent())
3718 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3719 // R_X86_64_RELATIVE assumes a 64-bit relocation.
3720 if (r_type
!= elfcpp::R_X86_64_GOT32
)
3722 unsigned int got_offset
=
3723 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
3724 rela_dyn
->add_local_relative(object
, r_sym
,
3725 elfcpp::R_X86_64_RELATIVE
,
3726 got
, got_offset
, 0, is_ifunc
);
3730 this->check_non_pic(object
, r_type
, NULL
);
3732 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
3733 rela_dyn
->add_local(
3734 object
, r_sym
, r_type
, got
,
3735 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
3739 // For GOTPLT64, we'd normally want a PLT section, but since
3740 // we know this is a local symbol, no PLT is needed.
3744 case elfcpp::R_X86_64_COPY
:
3745 case elfcpp::R_X86_64_GLOB_DAT
:
3746 case elfcpp::R_X86_64_JUMP_SLOT
:
3747 case elfcpp::R_X86_64_RELATIVE
:
3748 case elfcpp::R_X86_64_IRELATIVE
:
3749 // These are outstanding tls relocs, which are unexpected when linking
3750 case elfcpp::R_X86_64_TPOFF64
:
3751 case elfcpp::R_X86_64_DTPMOD64
:
3752 case elfcpp::R_X86_64_TLSDESC
:
3753 gold_error(_("%s: unexpected reloc %u in object file"),
3754 object
->name().c_str(), r_type
);
3757 // These are initial tls relocs, which are expected when linking
3758 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3759 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3760 case elfcpp::R_X86_64_TLSDESC_CALL
:
3761 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3762 case elfcpp::R_X86_64_DTPOFF32
:
3763 case elfcpp::R_X86_64_DTPOFF64
:
3764 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3765 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3767 bool output_is_shared
= parameters
->options().shared();
3768 const tls::Tls_optimization optimized_type
3769 = Target_x86_64
<size
>::optimize_tls_reloc(!output_is_shared
,
3773 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
3774 if (optimized_type
== tls::TLSOPT_NONE
)
3776 // Create a pair of GOT entries for the module index and
3777 // dtv-relative offset.
3778 Output_data_got
<64, false>* got
3779 = target
->got_section(symtab
, layout
);
3780 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3781 unsigned int shndx
= lsym
.get_st_shndx();
3783 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
3785 object
->error(_("local symbol %u has bad shndx %u"),
3788 got
->add_local_pair_with_rel(object
, r_sym
,
3791 target
->rela_dyn_section(layout
),
3792 elfcpp::R_X86_64_DTPMOD64
);
3794 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3795 unsupported_reloc_local(object
, r_type
);
3798 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3799 target
->define_tls_base_symbol(symtab
, layout
);
3800 if (optimized_type
== tls::TLSOPT_NONE
)
3802 // Create reserved PLT and GOT entries for the resolver.
3803 target
->reserve_tlsdesc_entries(symtab
, layout
);
3805 // Generate a double GOT entry with an
3806 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
3807 // is resolved lazily, so the GOT entry needs to be in
3808 // an area in .got.plt, not .got. Call got_section to
3809 // make sure the section has been created.
3810 target
->got_section(symtab
, layout
);
3811 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
3812 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3813 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
3815 unsigned int got_offset
= got
->add_constant(0);
3816 got
->add_constant(0);
3817 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
3819 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
3820 // We store the arguments we need in a vector, and
3821 // use the index into the vector as the parameter
3822 // to pass to the target specific routines.
3823 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
3824 void* arg
= reinterpret_cast<void*>(intarg
);
3825 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
3826 got
, got_offset
, 0);
3829 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3830 unsupported_reloc_local(object
, r_type
);
3833 case elfcpp::R_X86_64_TLSDESC_CALL
:
3836 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3837 if (optimized_type
== tls::TLSOPT_NONE
)
3839 // Create a GOT entry for the module index.
3840 target
->got_mod_index_entry(symtab
, layout
, object
);
3842 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3843 unsupported_reloc_local(object
, r_type
);
3846 case elfcpp::R_X86_64_DTPOFF32
:
3847 case elfcpp::R_X86_64_DTPOFF64
:
3850 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3851 layout
->set_has_static_tls();
3852 if (optimized_type
== tls::TLSOPT_NONE
)
3854 // Create a GOT entry for the tp-relative offset.
3855 Output_data_got
<64, false>* got
3856 = target
->got_section(symtab
, layout
);
3857 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3858 got
->add_local_with_rel(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
3859 target
->rela_dyn_section(layout
),
3860 elfcpp::R_X86_64_TPOFF64
);
3862 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3863 unsupported_reloc_local(object
, r_type
);
3866 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3867 layout
->set_has_static_tls();
3868 if (output_is_shared
)
3869 unsupported_reloc_local(object
, r_type
);
3878 case elfcpp::R_X86_64_SIZE32
:
3879 case elfcpp::R_X86_64_SIZE64
:
3881 gold_error(_("%s: unsupported reloc %u against local symbol"),
3882 object
->name().c_str(), r_type
);
3888 // Report an unsupported relocation against a global symbol.
3892 Target_x86_64
<size
>::Scan::unsupported_reloc_global(
3893 Sized_relobj_file
<size
, false>* object
,
3894 unsigned int r_type
,
3897 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3898 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
3901 // Returns true if this relocation type could be that of a function pointer.
3904 Target_x86_64
<size
>::Scan::possible_function_pointer_reloc(
3905 Sized_relobj_file
<size
, false>* src_obj
,
3906 unsigned int src_indx
,
3907 unsigned int r_offset
,
3908 unsigned int r_type
)
3912 case elfcpp::R_X86_64_64
:
3913 case elfcpp::R_X86_64_32
:
3914 case elfcpp::R_X86_64_32S
:
3915 case elfcpp::R_X86_64_16
:
3916 case elfcpp::R_X86_64_8
:
3917 case elfcpp::R_X86_64_GOT64
:
3918 case elfcpp::R_X86_64_GOT32
:
3919 case elfcpp::R_X86_64_GOTPCREL64
:
3920 case elfcpp::R_X86_64_GOTPCREL
:
3921 case elfcpp::R_X86_64_GOTPCRELX
:
3922 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3923 case elfcpp::R_X86_64_GOTPLT64
:
3927 case elfcpp::R_X86_64_PC32
:
3929 // This relocation may be used both for function calls and
3930 // for taking address of a function. We distinguish between
3931 // them by checking the opcodes.
3932 uint64_t sh_flags
= src_obj
->section_flags(src_indx
);
3933 bool is_executable
= (sh_flags
& elfcpp::SHF_EXECINSTR
) != 0;
3936 section_size_type stype
;
3937 const unsigned char* view
= src_obj
->section_contents(src_indx
,
3943 && view
[r_offset
- 1] == 0xe8)
3948 && view
[r_offset
- 1] == 0xe9)
3951 // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3953 && view
[r_offset
- 2] == 0x0f
3954 && view
[r_offset
- 1] >= 0x80
3955 && view
[r_offset
- 1] <= 0x8f)
3959 // Be conservative and treat all others as function pointers.
3966 // For safe ICF, scan a relocation for a local symbol to check if it
3967 // corresponds to a function pointer being taken. In that case mark
3968 // the function whose pointer was taken as not foldable.
3972 Target_x86_64
<size
>::Scan::local_reloc_may_be_function_pointer(
3975 Target_x86_64
<size
>* ,
3976 Sized_relobj_file
<size
, false>* src_obj
,
3977 unsigned int src_indx
,
3979 const elfcpp::Rela
<size
, false>& reloc
,
3980 unsigned int r_type
,
3981 const elfcpp::Sym
<size
, false>&)
3983 // When building a shared library, do not fold any local symbols as it is
3984 // not possible to distinguish pointer taken versus a call by looking at
3985 // the relocation types.
3986 if (parameters
->options().shared())
3989 return possible_function_pointer_reloc(src_obj
, src_indx
,
3990 reloc
.get_r_offset(), r_type
);
3993 // For safe ICF, scan a relocation for a global symbol to check if it
3994 // corresponds to a function pointer being taken. In that case mark
3995 // the function whose pointer was taken as not foldable.
3999 Target_x86_64
<size
>::Scan::global_reloc_may_be_function_pointer(
4002 Target_x86_64
<size
>* ,
4003 Sized_relobj_file
<size
, false>* src_obj
,
4004 unsigned int src_indx
,
4006 const elfcpp::Rela
<size
, false>& reloc
,
4007 unsigned int r_type
,
4010 // When building a shared library, do not fold symbols whose visibility
4011 // is hidden, internal or protected.
4012 if (parameters
->options().shared()
4013 && (gsym
->visibility() == elfcpp::STV_INTERNAL
4014 || gsym
->visibility() == elfcpp::STV_PROTECTED
4015 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
4018 return possible_function_pointer_reloc(src_obj
, src_indx
,
4019 reloc
.get_r_offset(), r_type
);
4022 // Scan a relocation for a global symbol.
4026 Target_x86_64
<size
>::Scan::global(Symbol_table
* symtab
,
4028 Target_x86_64
<size
>* target
,
4029 Sized_relobj_file
<size
, false>* object
,
4030 unsigned int data_shndx
,
4031 Output_section
* output_section
,
4032 const elfcpp::Rela
<size
, false>& reloc
,
4033 unsigned int r_type
,
4036 // A STT_GNU_IFUNC symbol may require a PLT entry.
4037 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
4038 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
4039 target
->make_plt_entry(symtab
, layout
, gsym
);
4043 case elfcpp::R_X86_64_NONE
:
4044 case elfcpp::R_X86_64_GNU_VTINHERIT
:
4045 case elfcpp::R_X86_64_GNU_VTENTRY
:
4048 case elfcpp::R_X86_64_64
:
4049 case elfcpp::R_X86_64_32
:
4050 case elfcpp::R_X86_64_32S
:
4051 case elfcpp::R_X86_64_16
:
4052 case elfcpp::R_X86_64_8
:
4054 // Make a PLT entry if necessary.
4055 if (gsym
->needs_plt_entry())
4057 target
->make_plt_entry(symtab
, layout
, gsym
);
4058 // Since this is not a PC-relative relocation, we may be
4059 // taking the address of a function. In that case we need to
4060 // set the entry in the dynamic symbol table to the address of
4062 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
4063 gsym
->set_needs_dynsym_value();
4065 // Make a dynamic relocation if necessary.
4066 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
4068 if (!parameters
->options().output_is_position_independent()
4069 && gsym
->may_need_copy_reloc())
4071 target
->copy_reloc(symtab
, layout
, object
,
4072 data_shndx
, output_section
, gsym
, reloc
);
4074 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
4075 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
4076 && gsym
->type() == elfcpp::STT_GNU_IFUNC
4077 && gsym
->can_use_relative_reloc(false)
4078 && !gsym
->is_from_dynobj()
4079 && !gsym
->is_undefined()
4080 && !gsym
->is_preemptible())
4082 // Use an IRELATIVE reloc for a locally defined
4083 // STT_GNU_IFUNC symbol. This makes a function
4084 // address in a PIE executable match the address in a
4085 // shared library that it links against.
4086 Reloc_section
* rela_dyn
=
4087 target
->rela_irelative_section(layout
);
4088 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
4089 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
4090 output_section
, object
,
4092 reloc
.get_r_offset(),
4093 reloc
.get_r_addend());
4095 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
4096 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
4097 && gsym
->can_use_relative_reloc(false))
4099 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4100 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
4101 output_section
, object
,
4103 reloc
.get_r_offset(),
4104 reloc
.get_r_addend(), false);
4108 this->check_non_pic(object
, r_type
, gsym
);
4109 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4110 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
4111 data_shndx
, reloc
.get_r_offset(),
4112 reloc
.get_r_addend());
4118 case elfcpp::R_X86_64_PC64
:
4119 case elfcpp::R_X86_64_PC32
:
4120 case elfcpp::R_X86_64_PC32_BND
:
4121 case elfcpp::R_X86_64_PC16
:
4122 case elfcpp::R_X86_64_PC8
:
4124 // Make a PLT entry if necessary.
4125 if (gsym
->needs_plt_entry())
4126 target
->make_plt_entry(symtab
, layout
, gsym
);
4127 // Make a dynamic relocation if necessary.
4128 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
4130 if (parameters
->options().output_is_executable()
4131 && gsym
->may_need_copy_reloc())
4133 target
->copy_reloc(symtab
, layout
, object
,
4134 data_shndx
, output_section
, gsym
, reloc
);
4138 this->check_non_pic(object
, r_type
, gsym
);
4139 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4140 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
4141 data_shndx
, reloc
.get_r_offset(),
4142 reloc
.get_r_addend());
4148 case elfcpp::R_X86_64_GOT64
:
4149 case elfcpp::R_X86_64_GOT32
:
4150 case elfcpp::R_X86_64_GOTPCREL64
:
4151 case elfcpp::R_X86_64_GOTPCREL
:
4152 case elfcpp::R_X86_64_GOTPCRELX
:
4153 case elfcpp::R_X86_64_REX_GOTPCRELX
:
4154 case elfcpp::R_X86_64_GOTPLT64
:
4156 // The symbol requires a GOT entry.
4157 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
4159 // If we convert this from
4160 // mov foo@GOTPCREL(%rip), %reg
4161 // to lea foo(%rip), %reg.
4164 // (callq|jmpq) *foo@GOTPCRELX(%rip) to
4166 // in Relocate::relocate, then there is nothing to do here.
4167 // We cannot make these optimizations in incremental linking mode,
4168 // because we look at the opcode to decide whether or not to make
4169 // change, and during an incremental update, the change may have
4170 // already been applied.
4172 Lazy_view
<size
> view(object
, data_shndx
);
4173 size_t r_offset
= reloc
.get_r_offset();
4174 if (!parameters
->incremental()
4176 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
, r_type
,
4180 if (!parameters
->incremental()
4182 && Target_x86_64
<size
>::can_convert_callq_to_direct(gsym
, r_type
,
4187 if (gsym
->final_value_is_known())
4189 // For a STT_GNU_IFUNC symbol we want the PLT address.
4190 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
4191 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
4193 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
4197 // If this symbol is not fully resolved, we need to add a
4198 // dynamic relocation for it.
4199 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4201 // Use a GLOB_DAT rather than a RELATIVE reloc if:
4203 // 1) The symbol may be defined in some other module.
4205 // 2) We are building a shared library and this is a
4206 // protected symbol; using GLOB_DAT means that the dynamic
4207 // linker can use the address of the PLT in the main
4208 // executable when appropriate so that function address
4209 // comparisons work.
4211 // 3) This is a STT_GNU_IFUNC symbol in position dependent
4212 // code, again so that function address comparisons work.
4213 if (gsym
->is_from_dynobj()
4214 || gsym
->is_undefined()
4215 || gsym
->is_preemptible()
4216 || (gsym
->visibility() == elfcpp::STV_PROTECTED
4217 && parameters
->options().shared())
4218 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
4219 && parameters
->options().output_is_position_independent()))
4220 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
4221 elfcpp::R_X86_64_GLOB_DAT
);
4224 // For a STT_GNU_IFUNC symbol we want to write the PLT
4225 // offset into the GOT, so that function pointer
4226 // comparisons work correctly.
4228 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
4229 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
4232 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
4233 // Tell the dynamic linker to use the PLT address
4234 // when resolving relocations.
4235 if (gsym
->is_from_dynobj()
4236 && !parameters
->options().shared())
4237 gsym
->set_needs_dynsym_value();
4241 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
4242 rela_dyn
->add_global_relative(gsym
,
4243 elfcpp::R_X86_64_RELATIVE
,
4244 got
, got_off
, 0, false);
4251 case elfcpp::R_X86_64_PLT32
:
4252 case elfcpp::R_X86_64_PLT32_BND
:
4253 // If the symbol is fully resolved, this is just a PC32 reloc.
4254 // Otherwise we need a PLT entry.
4255 if (gsym
->final_value_is_known())
4257 // If building a shared library, we can also skip the PLT entry
4258 // if the symbol is defined in the output file and is protected
4260 if (gsym
->is_defined()
4261 && !gsym
->is_from_dynobj()
4262 && !gsym
->is_preemptible())
4264 target
->make_plt_entry(symtab
, layout
, gsym
);
4267 case elfcpp::R_X86_64_GOTPC32
:
4268 case elfcpp::R_X86_64_GOTOFF64
:
4269 case elfcpp::R_X86_64_GOTPC64
:
4270 case elfcpp::R_X86_64_PLTOFF64
:
4271 // We need a GOT section.
4272 target
->got_section(symtab
, layout
);
4273 // For PLTOFF64, we also need a PLT entry (but only if the
4274 // symbol is not fully resolved).
4275 if (r_type
== elfcpp::R_X86_64_PLTOFF64
4276 && !gsym
->final_value_is_known())
4277 target
->make_plt_entry(symtab
, layout
, gsym
);
4280 case elfcpp::R_X86_64_COPY
:
4281 case elfcpp::R_X86_64_GLOB_DAT
:
4282 case elfcpp::R_X86_64_JUMP_SLOT
:
4283 case elfcpp::R_X86_64_RELATIVE
:
4284 case elfcpp::R_X86_64_IRELATIVE
:
4285 // These are outstanding tls relocs, which are unexpected when linking
4286 case elfcpp::R_X86_64_TPOFF64
:
4287 case elfcpp::R_X86_64_DTPMOD64
:
4288 case elfcpp::R_X86_64_TLSDESC
:
4289 gold_error(_("%s: unexpected reloc %u in object file"),
4290 object
->name().c_str(), r_type
);
4293 // These are initial tls relocs, which are expected for global()
4294 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
4295 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
4296 case elfcpp::R_X86_64_TLSDESC_CALL
:
4297 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4298 case elfcpp::R_X86_64_DTPOFF32
:
4299 case elfcpp::R_X86_64_DTPOFF64
:
4300 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4301 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4303 // For the Initial-Exec model, we can treat undef symbols as final
4304 // when building an executable.
4305 const bool is_final
= (gsym
->final_value_is_known() ||
4306 (r_type
== elfcpp::R_X86_64_GOTTPOFF
&&
4307 gsym
->is_undefined() &&
4308 parameters
->options().output_is_executable()));
4309 const tls::Tls_optimization optimized_type
4310 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
4313 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
4314 if (optimized_type
== tls::TLSOPT_NONE
)
4316 // Create a pair of GOT entries for the module index and
4317 // dtv-relative offset.
4318 Output_data_got
<64, false>* got
4319 = target
->got_section(symtab
, layout
);
4320 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
4321 target
->rela_dyn_section(layout
),
4322 elfcpp::R_X86_64_DTPMOD64
,
4323 elfcpp::R_X86_64_DTPOFF64
);
4325 else if (optimized_type
== tls::TLSOPT_TO_IE
)
4327 // Create a GOT entry for the tp-relative offset.
4328 Output_data_got
<64, false>* got
4329 = target
->got_section(symtab
, layout
);
4330 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
4331 target
->rela_dyn_section(layout
),
4332 elfcpp::R_X86_64_TPOFF64
);
4334 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4335 unsupported_reloc_global(object
, r_type
, gsym
);
4338 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
4339 target
->define_tls_base_symbol(symtab
, layout
);
4340 if (optimized_type
== tls::TLSOPT_NONE
)
4342 // Create reserved PLT and GOT entries for the resolver.
4343 target
->reserve_tlsdesc_entries(symtab
, layout
);
4345 // Create a double GOT entry with an R_X86_64_TLSDESC
4346 // reloc. The R_X86_64_TLSDESC reloc is resolved
4347 // lazily, so the GOT entry needs to be in an area in
4348 // .got.plt, not .got. Call got_section to make sure
4349 // the section has been created.
4350 target
->got_section(symtab
, layout
);
4351 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
4352 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
4353 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
4354 elfcpp::R_X86_64_TLSDESC
, 0);
4356 else if (optimized_type
== tls::TLSOPT_TO_IE
)
4358 // Create a GOT entry for the tp-relative offset.
4359 Output_data_got
<64, false>* got
4360 = target
->got_section(symtab
, layout
);
4361 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
4362 target
->rela_dyn_section(layout
),
4363 elfcpp::R_X86_64_TPOFF64
);
4365 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4366 unsupported_reloc_global(object
, r_type
, gsym
);
4369 case elfcpp::R_X86_64_TLSDESC_CALL
:
4372 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4373 if (optimized_type
== tls::TLSOPT_NONE
)
4375 // Create a GOT entry for the module index.
4376 target
->got_mod_index_entry(symtab
, layout
, object
);
4378 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4379 unsupported_reloc_global(object
, r_type
, gsym
);
4382 case elfcpp::R_X86_64_DTPOFF32
:
4383 case elfcpp::R_X86_64_DTPOFF64
:
4386 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4387 layout
->set_has_static_tls();
4388 if (optimized_type
== tls::TLSOPT_NONE
)
4390 // Create a GOT entry for the tp-relative offset.
4391 Output_data_got
<64, false>* got
4392 = target
->got_section(symtab
, layout
);
4393 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
4394 target
->rela_dyn_section(layout
),
4395 elfcpp::R_X86_64_TPOFF64
);
4397 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4398 unsupported_reloc_global(object
, r_type
, gsym
);
4401 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4402 layout
->set_has_static_tls();
4403 if (parameters
->options().shared())
4404 unsupported_reloc_global(object
, r_type
, gsym
);
4413 case elfcpp::R_X86_64_SIZE32
:
4414 case elfcpp::R_X86_64_SIZE64
:
4416 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
4417 object
->name().c_str(), r_type
,
4418 gsym
->demangled_name().c_str());
4425 Target_x86_64
<size
>::gc_process_relocs(Symbol_table
* symtab
,
4427 Sized_relobj_file
<size
, false>* object
,
4428 unsigned int data_shndx
,
4429 unsigned int sh_type
,
4430 const unsigned char* prelocs
,
4432 Output_section
* output_section
,
4433 bool needs_special_offset_handling
,
4434 size_t local_symbol_count
,
4435 const unsigned char* plocal_symbols
)
4437 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4440 if (sh_type
== elfcpp::SHT_REL
)
4445 gold::gc_process_relocs
<size
, false, Target_x86_64
<size
>, Scan
,
4455 needs_special_offset_handling
,
4460 // Scan relocations for a section.
4464 Target_x86_64
<size
>::scan_relocs(Symbol_table
* symtab
,
4466 Sized_relobj_file
<size
, false>* object
,
4467 unsigned int data_shndx
,
4468 unsigned int sh_type
,
4469 const unsigned char* prelocs
,
4471 Output_section
* output_section
,
4472 bool needs_special_offset_handling
,
4473 size_t local_symbol_count
,
4474 const unsigned char* plocal_symbols
)
4476 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4479 if (sh_type
== elfcpp::SHT_REL
)
4481 gold_error(_("%s: unsupported REL reloc section"),
4482 object
->name().c_str());
4486 gold::scan_relocs
<size
, false, Target_x86_64
<size
>, Scan
, Classify_reloc
>(
4495 needs_special_offset_handling
,
4500 // Finalize the sections.
4504 Target_x86_64
<size
>::do_finalize_sections(
4506 const Input_objects
*,
4507 Symbol_table
* symtab
)
4509 const Reloc_section
* rel_plt
= (this->plt_
== NULL
4511 : this->plt_
->rela_plt());
4512 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
4513 this->rela_dyn_
, true, false);
4515 // Fill in some more dynamic tags.
4516 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
4519 if (this->plt_
!= NULL
4520 && this->plt_
->output_section() != NULL
4521 && this->plt_
->has_tlsdesc_entry())
4523 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
4524 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
4525 this->got_
->finalize_data_size();
4526 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
4527 this->plt_
, plt_offset
);
4528 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
4529 this->got_
, got_offset
);
4533 // Emit any relocs we saved in an attempt to avoid generating COPY
4535 if (this->copy_relocs_
.any_saved_relocs())
4536 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
4538 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
4539 // the .got.plt section.
4540 Symbol
* sym
= this->global_offset_table_
;
4543 uint64_t data_size
= this->got_plt_
->current_data_size();
4544 symtab
->get_sized_symbol
<size
>(sym
)->set_symsize(data_size
);
4547 if (parameters
->doing_static_link()
4548 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
4550 // If linking statically, make sure that the __rela_iplt symbols
4551 // were defined if necessary, even if we didn't create a PLT.
4552 static const Define_symbol_in_segment syms
[] =
4555 "__rela_iplt_start", // name
4556 elfcpp::PT_LOAD
, // segment_type
4557 elfcpp::PF_W
, // segment_flags_set
4558 elfcpp::PF(0), // segment_flags_clear
4561 elfcpp::STT_NOTYPE
, // type
4562 elfcpp::STB_GLOBAL
, // binding
4563 elfcpp::STV_HIDDEN
, // visibility
4565 Symbol::SEGMENT_START
, // offset_from_base
4569 "__rela_iplt_end", // name
4570 elfcpp::PT_LOAD
, // segment_type
4571 elfcpp::PF_W
, // segment_flags_set
4572 elfcpp::PF(0), // segment_flags_clear
4575 elfcpp::STT_NOTYPE
, // type
4576 elfcpp::STB_GLOBAL
, // binding
4577 elfcpp::STV_HIDDEN
, // visibility
4579 Symbol::SEGMENT_START
, // offset_from_base
4584 symtab
->define_symbols(layout
, 2, syms
,
4585 layout
->script_options()->saw_sections_clause());
4589 // For x32, we need to handle PC-relative relocations using full 64-bit
4590 // arithmetic, so that we can detect relocation overflows properly.
4591 // This class overrides the pcrela32_check methods from the defaults in
4592 // Relocate_functions in reloc.h.
4595 class X86_64_relocate_functions
: public Relocate_functions
<size
, false>
4598 typedef Relocate_functions
<size
, false> Base
;
4600 // Do a simple PC relative relocation with the addend in the
4602 static inline typename
Base::Reloc_status
4603 pcrela32_check(unsigned char* view
,
4604 typename
elfcpp::Elf_types
<64>::Elf_Addr value
,
4605 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
4606 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
4608 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
4609 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
4610 value
= value
+ addend
- address
;
4611 elfcpp::Swap
<32, false>::writeval(wv
, value
);
4612 return (Bits
<32>::has_overflow(value
)
4613 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
4616 // Do a simple PC relative relocation with a Symbol_value with the
4617 // addend in the relocation.
4618 static inline typename
Base::Reloc_status
4619 pcrela32_check(unsigned char* view
,
4620 const Sized_relobj_file
<size
, false>* object
,
4621 const Symbol_value
<size
>* psymval
,
4622 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
4623 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
4625 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
4626 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
4627 typename
elfcpp::Elf_types
<64>::Elf_Addr value
;
4629 value
= psymval
->value(object
, addend
);
4632 // For negative addends, get the symbol value without
4633 // the addend, then add the addend using 64-bit arithmetic.
4634 value
= psymval
->value(object
, 0);
4638 elfcpp::Swap
<32, false>::writeval(wv
, value
);
4639 return (Bits
<32>::has_overflow(value
)
4640 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
4644 // Perform a relocation.
4648 Target_x86_64
<size
>::Relocate::relocate(
4649 const Relocate_info
<size
, false>* relinfo
,
4651 Target_x86_64
<size
>* target
,
4654 const unsigned char* preloc
,
4655 const Sized_symbol
<size
>* gsym
,
4656 const Symbol_value
<size
>* psymval
,
4657 unsigned char* view
,
4658 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4659 section_size_type view_size
)
4661 typedef X86_64_relocate_functions
<size
> Reloc_funcs
;
4662 const elfcpp::Rela
<size
, false> rela(preloc
);
4663 unsigned int r_type
= elfcpp::elf_r_type
<size
>(rela
.get_r_info());
4665 if (this->skip_call_tls_get_addr_
)
4667 if ((r_type
!= elfcpp::R_X86_64_PLT32
4668 && r_type
!= elfcpp::R_X86_64_GOTPCREL
4669 && r_type
!= elfcpp::R_X86_64_GOTPCRELX
4670 && r_type
!= elfcpp::R_X86_64_PLT32_BND
4671 && r_type
!= elfcpp::R_X86_64_PC32_BND
4672 && r_type
!= elfcpp::R_X86_64_PC32
)
4674 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
4676 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4677 _("missing expected TLS relocation"));
4678 this->skip_call_tls_get_addr_
= false;
4682 this->skip_call_tls_get_addr_
= false;
4690 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
4692 // Pick the value to use for symbols defined in the PLT.
4693 Symbol_value
<size
> symval
;
4695 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
4697 symval
.set_output_value(target
->plt_address_for_global(gsym
));
4700 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
4702 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4703 if (object
->local_has_plt_offset(r_sym
))
4705 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
4710 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4712 // Get the GOT offset if needed.
4713 // The GOT pointer points to the end of the GOT section.
4714 // We need to subtract the size of the GOT section to get
4715 // the actual offset to use in the relocation.
4716 bool have_got_offset
= false;
4717 // Since the actual offset is always negative, we use signed int to
4718 // support 64-bit GOT relocations.
4722 case elfcpp::R_X86_64_GOT32
:
4723 case elfcpp::R_X86_64_GOT64
:
4724 case elfcpp::R_X86_64_GOTPLT64
:
4725 case elfcpp::R_X86_64_GOTPCREL64
:
4728 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
4729 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
4733 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4734 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
4735 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
4736 - target
->got_size());
4738 have_got_offset
= true;
4745 typename
Reloc_funcs::Reloc_status rstatus
= Reloc_funcs::RELOC_OK
;
4749 case elfcpp::R_X86_64_NONE
:
4750 case elfcpp::R_X86_64_GNU_VTINHERIT
:
4751 case elfcpp::R_X86_64_GNU_VTENTRY
:
4754 case elfcpp::R_X86_64_64
:
4755 Reloc_funcs::rela64(view
, object
, psymval
, addend
);
4758 case elfcpp::R_X86_64_PC64
:
4759 Reloc_funcs::pcrela64(view
, object
, psymval
, addend
,
4763 case elfcpp::R_X86_64_32
:
4764 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
4765 Reloc_funcs::CHECK_UNSIGNED
);
4768 case elfcpp::R_X86_64_32S
:
4769 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
4770 Reloc_funcs::CHECK_SIGNED
);
4773 case elfcpp::R_X86_64_PC32
:
4774 case elfcpp::R_X86_64_PC32_BND
:
4775 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
4779 case elfcpp::R_X86_64_16
:
4780 Reloc_funcs::rela16(view
, object
, psymval
, addend
);
4783 case elfcpp::R_X86_64_PC16
:
4784 Reloc_funcs::pcrela16(view
, object
, psymval
, addend
, address
);
4787 case elfcpp::R_X86_64_8
:
4788 Reloc_funcs::rela8(view
, object
, psymval
, addend
);
4791 case elfcpp::R_X86_64_PC8
:
4792 Reloc_funcs::pcrela8(view
, object
, psymval
, addend
, address
);
4795 case elfcpp::R_X86_64_PLT32
:
4796 case elfcpp::R_X86_64_PLT32_BND
:
4797 gold_assert(gsym
== NULL
4798 || gsym
->has_plt_offset()
4799 || gsym
->final_value_is_known()
4800 || (gsym
->is_defined()
4801 && !gsym
->is_from_dynobj()
4802 && !gsym
->is_preemptible()));
4803 // Note: while this code looks the same as for R_X86_64_PC32, it
4804 // behaves differently because psymval was set to point to
4805 // the PLT entry, rather than the symbol, in Scan::global().
4806 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
4810 case elfcpp::R_X86_64_PLTOFF64
:
4813 gold_assert(gsym
->has_plt_offset()
4814 || gsym
->final_value_is_known());
4815 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
;
4816 // This is the address of GLOBAL_OFFSET_TABLE.
4817 got_address
= target
->got_plt_section()->address();
4818 Reloc_funcs::rela64(view
, object
, psymval
, addend
- got_address
);
4822 case elfcpp::R_X86_64_GOT32
:
4823 gold_assert(have_got_offset
);
4824 Reloc_funcs::rela32(view
, got_offset
, addend
);
4827 case elfcpp::R_X86_64_GOTPC32
:
4830 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4831 value
= target
->got_plt_section()->address();
4832 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
4836 case elfcpp::R_X86_64_GOT64
:
4837 case elfcpp::R_X86_64_GOTPLT64
:
4838 // R_X86_64_GOTPLT64 is obsolete and treated the same as
4840 gold_assert(have_got_offset
);
4841 Reloc_funcs::rela64(view
, got_offset
, addend
);
4844 case elfcpp::R_X86_64_GOTPC64
:
4847 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4848 value
= target
->got_plt_section()->address();
4849 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
4853 case elfcpp::R_X86_64_GOTOFF64
:
4855 typename
elfcpp::Elf_types
<size
>::Elf_Addr reladdr
;
4856 reladdr
= target
->got_plt_section()->address();
4857 Reloc_funcs::pcrela64(view
, object
, psymval
, addend
, reladdr
);
4861 case elfcpp::R_X86_64_GOTPCREL
:
4862 case elfcpp::R_X86_64_GOTPCRELX
:
4863 case elfcpp::R_X86_64_REX_GOTPCRELX
:
4866 // mov foo@GOTPCREL(%rip), %reg
4867 // to lea foo(%rip), %reg.
4869 if (!parameters
->incremental()
4871 && rela
.get_r_offset() >= 2
4873 && !psymval
->is_ifunc_symbol())
4875 && rela
.get_r_offset() >= 2
4876 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
, r_type
,
4880 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
4883 // callq *foo@GOTPCRELX(%rip) to
4885 // and jmpq *foo@GOTPCRELX(%rip) to
4888 else if (!parameters
->incremental()
4890 && rela
.get_r_offset() >= 2
4891 && Target_x86_64
<size
>::can_convert_callq_to_direct(gsym
,
4895 if (view
[-1] == 0x15)
4897 // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4898 // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
4901 // Convert GOTPCRELX to 32-bit pc relative reloc.
4902 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
4906 // Convert jmpq *foo@GOTPCRELX(%rip) to
4909 // The opcode of direct jmpq is 0xe9.
4911 // The opcode of nop is 0x90.
4913 // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
4914 // relative and since the instruction following the jmpq is now
4915 // the nop, offset the address by 1 byte. The start of the
4916 // relocation also moves ahead by 1 byte.
4917 Reloc_funcs::pcrela32(&view
[-1], object
, psymval
, addend
,
4925 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
4926 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
4927 - target
->got_size());
4931 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4932 gold_assert(object
->local_has_got_offset(r_sym
,
4933 GOT_TYPE_STANDARD
));
4934 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
4935 - target
->got_size());
4937 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4938 value
= target
->got_plt_section()->address() + got_offset
;
4939 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
4944 case elfcpp::R_X86_64_GOTPCREL64
:
4946 gold_assert(have_got_offset
);
4947 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4948 value
= target
->got_plt_section()->address() + got_offset
;
4949 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
4953 case elfcpp::R_X86_64_COPY
:
4954 case elfcpp::R_X86_64_GLOB_DAT
:
4955 case elfcpp::R_X86_64_JUMP_SLOT
:
4956 case elfcpp::R_X86_64_RELATIVE
:
4957 case elfcpp::R_X86_64_IRELATIVE
:
4958 // These are outstanding tls relocs, which are unexpected when linking
4959 case elfcpp::R_X86_64_TPOFF64
:
4960 case elfcpp::R_X86_64_DTPMOD64
:
4961 case elfcpp::R_X86_64_TLSDESC
:
4962 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4963 _("unexpected reloc %u in object file"),
4967 // These are initial tls relocs, which are expected when linking
4968 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
4969 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
4970 case elfcpp::R_X86_64_TLSDESC_CALL
:
4971 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4972 case elfcpp::R_X86_64_DTPOFF32
:
4973 case elfcpp::R_X86_64_DTPOFF64
:
4974 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4975 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4976 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
4977 view
, address
, view_size
);
4980 case elfcpp::R_X86_64_SIZE32
:
4981 case elfcpp::R_X86_64_SIZE64
:
4983 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4984 _("unsupported reloc %u"),
4989 if (rstatus
== Reloc_funcs::RELOC_OVERFLOW
)
4993 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4994 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4995 _("relocation overflow: "
4996 "reference to local symbol %u in %s"),
4997 r_sym
, object
->name().c_str());
4999 else if (gsym
->is_defined() && gsym
->source() == Symbol::FROM_OBJECT
)
5001 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5002 _("relocation overflow: "
5003 "reference to '%s' defined in %s"),
5005 gsym
->object()->name().c_str());
5009 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5010 _("relocation overflow: reference to '%s'"),
5018 // Perform a TLS relocation.
5022 Target_x86_64
<size
>::Relocate::relocate_tls(
5023 const Relocate_info
<size
, false>* relinfo
,
5024 Target_x86_64
<size
>* target
,
5026 const elfcpp::Rela
<size
, false>& rela
,
5027 unsigned int r_type
,
5028 const Sized_symbol
<size
>* gsym
,
5029 const Symbol_value
<size
>* psymval
,
5030 unsigned char* view
,
5031 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5032 section_size_type view_size
)
5034 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
5036 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
5037 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
5038 elfcpp::Shdr
<size
, false> data_shdr(relinfo
->data_shdr
);
5039 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
5041 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
5043 const bool is_final
= (gsym
== NULL
5044 ? !parameters
->options().shared()
5045 : gsym
->final_value_is_known());
5046 tls::Tls_optimization optimized_type
5047 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
5050 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
5051 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
5053 // If this code sequence is used in a non-executable section,
5054 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
5055 // on the assumption that it's being used by itself in a debug
5056 // section. Therefore, in the unlikely event that the code
5057 // sequence appears in a non-executable section, we simply
5058 // leave it unoptimized.
5059 optimized_type
= tls::TLSOPT_NONE
;
5061 if (optimized_type
== tls::TLSOPT_TO_LE
)
5063 if (tls_segment
== NULL
)
5065 gold_assert(parameters
->errors()->error_count() > 0
5066 || issue_undefined_symbol_error(gsym
));
5069 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
5070 rela
, r_type
, value
, view
,
5076 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
5077 ? GOT_TYPE_TLS_OFFSET
5078 : GOT_TYPE_TLS_PAIR
);
5079 unsigned int got_offset
;
5082 gold_assert(gsym
->has_got_offset(got_type
));
5083 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
5087 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5088 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
5089 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
5090 - target
->got_size());
5092 if (optimized_type
== tls::TLSOPT_TO_IE
)
5094 value
= target
->got_plt_section()->address() + got_offset
;
5095 this->tls_gd_to_ie(relinfo
, relnum
, rela
, r_type
,
5096 value
, view
, address
, view_size
);
5099 else if (optimized_type
== tls::TLSOPT_NONE
)
5101 // Relocate the field with the offset of the pair of GOT
5103 value
= target
->got_plt_section()->address() + got_offset
;
5104 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5109 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5110 _("unsupported reloc %u"), r_type
);
5113 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
5114 case elfcpp::R_X86_64_TLSDESC_CALL
:
5115 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
5117 // See above comment for R_X86_64_TLSGD.
5118 optimized_type
= tls::TLSOPT_NONE
;
5120 if (optimized_type
== tls::TLSOPT_TO_LE
)
5122 if (tls_segment
== NULL
)
5124 gold_assert(parameters
->errors()->error_count() > 0
5125 || issue_undefined_symbol_error(gsym
));
5128 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
5129 rela
, r_type
, value
, view
,
5135 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
5136 ? GOT_TYPE_TLS_OFFSET
5137 : GOT_TYPE_TLS_DESC
);
5138 unsigned int got_offset
= 0;
5139 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
5140 && optimized_type
== tls::TLSOPT_NONE
)
5142 // We created GOT entries in the .got.tlsdesc portion of
5143 // the .got.plt section, but the offset stored in the
5144 // symbol is the offset within .got.tlsdesc.
5145 got_offset
= (target
->got_size()
5146 + target
->got_plt_section()->data_size());
5150 gold_assert(gsym
->has_got_offset(got_type
));
5151 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
5155 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5156 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
5157 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
5158 - target
->got_size());
5160 if (optimized_type
== tls::TLSOPT_TO_IE
)
5162 value
= target
->got_plt_section()->address() + got_offset
;
5163 this->tls_desc_gd_to_ie(relinfo
, relnum
,
5164 rela
, r_type
, value
, view
, address
,
5168 else if (optimized_type
== tls::TLSOPT_NONE
)
5170 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
5172 // Relocate the field with the offset of the pair of GOT
5174 value
= target
->got_plt_section()->address() + got_offset
;
5175 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5181 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5182 _("unsupported reloc %u"), r_type
);
5185 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
5186 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
5188 // See above comment for R_X86_64_TLSGD.
5189 optimized_type
= tls::TLSOPT_NONE
;
5191 if (optimized_type
== tls::TLSOPT_TO_LE
)
5193 if (tls_segment
== NULL
)
5195 gold_assert(parameters
->errors()->error_count() > 0
5196 || issue_undefined_symbol_error(gsym
));
5199 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
5200 value
, view
, view_size
);
5203 else if (optimized_type
== tls::TLSOPT_NONE
)
5205 // Relocate the field with the offset of the GOT entry for
5206 // the module index.
5207 unsigned int got_offset
;
5208 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
5209 - target
->got_size());
5210 value
= target
->got_plt_section()->address() + got_offset
;
5211 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5215 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5216 _("unsupported reloc %u"), r_type
);
5219 case elfcpp::R_X86_64_DTPOFF32
:
5220 // This relocation type is used in debugging information.
5221 // In that case we need to not optimize the value. If the
5222 // section is not executable, then we assume we should not
5223 // optimize this reloc. See comments above for R_X86_64_TLSGD,
5224 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
5226 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
5228 if (tls_segment
== NULL
)
5230 gold_assert(parameters
->errors()->error_count() > 0
5231 || issue_undefined_symbol_error(gsym
));
5234 value
-= tls_segment
->memsz();
5236 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
5239 case elfcpp::R_X86_64_DTPOFF64
:
5240 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
5241 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
5243 if (tls_segment
== NULL
)
5245 gold_assert(parameters
->errors()->error_count() > 0
5246 || issue_undefined_symbol_error(gsym
));
5249 value
-= tls_segment
->memsz();
5251 Relocate_functions
<size
, false>::rela64(view
, value
, addend
);
5254 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
5256 && gsym
->is_undefined()
5257 && parameters
->options().output_is_executable())
5259 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
5261 r_type
, value
, view
,
5265 else if (optimized_type
== tls::TLSOPT_TO_LE
)
5267 if (tls_segment
== NULL
)
5269 gold_assert(parameters
->errors()->error_count() > 0
5270 || issue_undefined_symbol_error(gsym
));
5273 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
5275 r_type
, value
, view
,
5279 else if (optimized_type
== tls::TLSOPT_NONE
)
5281 // Relocate the field with the offset of the GOT entry for
5282 // the tp-relative offset of the symbol.
5283 unsigned int got_offset
;
5286 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
5287 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
5288 - target
->got_size());
5292 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5293 gold_assert(object
->local_has_got_offset(r_sym
,
5294 GOT_TYPE_TLS_OFFSET
));
5295 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
5296 - target
->got_size());
5298 value
= target
->got_plt_section()->address() + got_offset
;
5299 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5303 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5304 _("unsupported reloc type %u"),
5308 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
5309 if (tls_segment
== NULL
)
5311 gold_assert(parameters
->errors()->error_count() > 0
5312 || issue_undefined_symbol_error(gsym
));
5315 value
-= tls_segment
->memsz();
5316 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
5321 // Do a relocation in which we convert a TLS General-Dynamic to an
5326 Target_x86_64
<size
>::Relocate::tls_gd_to_ie(
5327 const Relocate_info
<size
, false>* relinfo
,
5329 const elfcpp::Rela
<size
, false>& rela
,
5331 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5332 unsigned char* view
,
5333 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5334 section_size_type view_size
)
5337 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5338 // .word 0x6666; rex64; call __tls_get_addr@PLT
5339 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5340 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5341 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5342 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5344 // leaq foo@tlsgd(%rip),%rdi;
5345 // .word 0x6666; rex64; call __tls_get_addr@PLT
5346 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5347 // leaq foo@tlsgd(%rip),%rdi;
5348 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5349 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5351 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
5352 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5353 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0
5354 || memcmp(view
+ 4, "\x66\x48\xff", 3) == 0));
5358 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5360 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5361 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
5362 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5367 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5369 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5370 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
5371 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5375 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
5376 Relocate_functions
<size
, false>::pcrela32(view
+ 8, value
, addend
- 8,
5379 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5381 this->skip_call_tls_get_addr_
= true;
5384 // Do a relocation in which we convert a TLS General-Dynamic to a
5389 Target_x86_64
<size
>::Relocate::tls_gd_to_le(
5390 const Relocate_info
<size
, false>* relinfo
,
5392 Output_segment
* tls_segment
,
5393 const elfcpp::Rela
<size
, false>& rela
,
5395 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5396 unsigned char* view
,
5397 section_size_type view_size
)
5400 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5401 // .word 0x6666; rex64; call __tls_get_addr@PLT
5402 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5403 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5404 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5405 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5407 // leaq foo@tlsgd(%rip),%rdi;
5408 // .word 0x6666; rex64; call __tls_get_addr@PLT
5409 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5410 // leaq foo@tlsgd(%rip),%rdi;
5411 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5412 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5414 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
5415 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5416 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0
5417 || memcmp(view
+ 4, "\x66\x48\xff", 3) == 0));
5421 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5423 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5424 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
5425 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5430 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5432 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5433 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
5435 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5439 value
-= tls_segment
->memsz();
5440 Relocate_functions
<size
, false>::rela32(view
+ 8, value
, 0);
5442 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5444 this->skip_call_tls_get_addr_
= true;
5447 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
5451 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_ie(
5452 const Relocate_info
<size
, false>* relinfo
,
5454 const elfcpp::Rela
<size
, false>& rela
,
5455 unsigned int r_type
,
5456 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5457 unsigned char* view
,
5458 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5459 section_size_type view_size
)
5461 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
5463 // leaq foo@tlsdesc(%rip), %rax
5464 // ==> movq foo@gottpoff(%rip), %rax
5465 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5466 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
5467 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5468 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
5470 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
5471 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
5475 // call *foo@tlscall(%rax)
5477 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
5478 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
5479 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5480 view
[0] == 0xff && view
[1] == 0x10);
5486 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
5490 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_le(
5491 const Relocate_info
<size
, false>* relinfo
,
5493 Output_segment
* tls_segment
,
5494 const elfcpp::Rela
<size
, false>& rela
,
5495 unsigned int r_type
,
5496 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5497 unsigned char* view
,
5498 section_size_type view_size
)
5500 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
5502 // leaq foo@tlsdesc(%rip), %rax
5503 // ==> movq foo@tpoff, %rax
5504 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5505 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
5506 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5507 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
5510 value
-= tls_segment
->memsz();
5511 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
5515 // call *foo@tlscall(%rax)
5517 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
5518 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
5519 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5520 view
[0] == 0xff && view
[1] == 0x10);
5528 Target_x86_64
<size
>::Relocate::tls_ld_to_le(
5529 const Relocate_info
<size
, false>* relinfo
,
5532 const elfcpp::Rela
<size
, false>& rela
,
5534 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
5535 unsigned char* view
,
5536 section_size_type view_size
)
5538 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
5540 // ... leq foo@dtpoff(%rax),%reg
5541 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5543 // ... leq foo@dtpoff(%rax),%reg
5544 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5545 // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
5547 // ... leq foo@dtpoff(%rax),%reg
5548 // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5550 // ... leq foo@dtpoff(%rax),%reg
5551 // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5553 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5554 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
5556 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5557 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
5559 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5560 view
[4] == 0xe8 || view
[4] == 0xff);
5562 if (view
[4] == 0xe8)
5565 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
5567 memcpy(view
- 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
5572 memcpy(view
- 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
5575 memcpy(view
- 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
5579 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5581 this->skip_call_tls_get_addr_
= true;
5584 // Do a relocation in which we convert a TLS Initial-Exec to a
5589 Target_x86_64
<size
>::Relocate::tls_ie_to_le(
5590 const Relocate_info
<size
, false>* relinfo
,
5592 Output_segment
* tls_segment
,
5593 const elfcpp::Rela
<size
, false>& rela
,
5595 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5596 unsigned char* view
,
5597 section_size_type view_size
)
5599 // We need to examine the opcodes to figure out which instruction we
5602 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
5603 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
5605 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5606 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
5608 unsigned char op1
= view
[-3];
5609 unsigned char op2
= view
[-2];
5610 unsigned char op3
= view
[-1];
5611 unsigned char reg
= op3
>> 3;
5618 else if (size
== 32 && op1
== 0x44)
5621 view
[-1] = 0xc0 | reg
;
5625 // Special handling for %rsp.
5628 else if (size
== 32 && op1
== 0x44)
5631 view
[-1] = 0xc0 | reg
;
5638 else if (size
== 32 && op1
== 0x44)
5641 view
[-1] = 0x80 | reg
| (reg
<< 3);
5644 if (tls_segment
!= NULL
)
5645 value
-= tls_segment
->memsz();
5646 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
5649 // Relocate section data.
5653 Target_x86_64
<size
>::relocate_section(
5654 const Relocate_info
<size
, false>* relinfo
,
5655 unsigned int sh_type
,
5656 const unsigned char* prelocs
,
5658 Output_section
* output_section
,
5659 bool needs_special_offset_handling
,
5660 unsigned char* view
,
5661 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5662 section_size_type view_size
,
5663 const Reloc_symbol_changes
* reloc_symbol_changes
)
5665 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5668 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5670 gold::relocate_section
<size
, false, Target_x86_64
<size
>, Relocate
,
5671 gold::Default_comdat_behavior
, Classify_reloc
>(
5677 needs_special_offset_handling
,
5681 reloc_symbol_changes
);
5684 // Apply an incremental relocation. Incremental relocations always refer
5685 // to global symbols.
5689 Target_x86_64
<size
>::apply_relocation(
5690 const Relocate_info
<size
, false>* relinfo
,
5691 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
5692 unsigned int r_type
,
5693 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
5695 unsigned char* view
,
5696 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5697 section_size_type view_size
)
5699 gold::apply_relocation
<size
, false, Target_x86_64
<size
>,
5700 typename Target_x86_64
<size
>::Relocate
>(
5712 // Scan the relocs during a relocatable link.
5716 Target_x86_64
<size
>::scan_relocatable_relocs(
5717 Symbol_table
* symtab
,
5719 Sized_relobj_file
<size
, false>* object
,
5720 unsigned int data_shndx
,
5721 unsigned int sh_type
,
5722 const unsigned char* prelocs
,
5724 Output_section
* output_section
,
5725 bool needs_special_offset_handling
,
5726 size_t local_symbol_count
,
5727 const unsigned char* plocal_symbols
,
5728 Relocatable_relocs
* rr
)
5730 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5732 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
5733 Scan_relocatable_relocs
;
5735 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5737 gold::scan_relocatable_relocs
<size
, false, Scan_relocatable_relocs
>(
5745 needs_special_offset_handling
,
5751 // Scan the relocs for --emit-relocs.
5755 Target_x86_64
<size
>::emit_relocs_scan(
5756 Symbol_table
* symtab
,
5758 Sized_relobj_file
<size
, false>* object
,
5759 unsigned int data_shndx
,
5760 unsigned int sh_type
,
5761 const unsigned char* prelocs
,
5763 Output_section
* output_section
,
5764 bool needs_special_offset_handling
,
5765 size_t local_symbol_count
,
5766 const unsigned char* plocal_syms
,
5767 Relocatable_relocs
* rr
)
5769 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5771 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
5772 Emit_relocs_strategy
;
5774 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5776 gold::scan_relocatable_relocs
<size
, false, Emit_relocs_strategy
>(
5784 needs_special_offset_handling
,
5790 // Relocate a section during a relocatable link.
5794 Target_x86_64
<size
>::relocate_relocs(
5795 const Relocate_info
<size
, false>* relinfo
,
5796 unsigned int sh_type
,
5797 const unsigned char* prelocs
,
5799 Output_section
* output_section
,
5800 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
5801 unsigned char* view
,
5802 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
5803 section_size_type view_size
,
5804 unsigned char* reloc_view
,
5805 section_size_type reloc_view_size
)
5807 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5810 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5812 gold::relocate_relocs
<size
, false, Classify_reloc
>(
5817 offset_in_output_section
,
5825 // Return the value to use for a dynamic which requires special
5826 // treatment. This is how we support equality comparisons of function
5827 // pointers across shared library boundaries, as described in the
5828 // processor specific ABI supplement.
5832 Target_x86_64
<size
>::do_dynsym_value(const Symbol
* gsym
) const
5834 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
5835 return this->plt_address_for_global(gsym
);
5838 // Return a string used to fill a code section with nops to take up
5839 // the specified length.
5843 Target_x86_64
<size
>::do_code_fill(section_size_type length
) const
5847 // Build a jmpq instruction to skip over the bytes.
5848 unsigned char jmp
[5];
5850 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
5851 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
5852 + std::string(length
- 5, static_cast<char>(0x90)));
5855 // Nop sequences of various lengths.
5856 const char nop1
[1] = { '\x90' }; // nop
5857 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
5858 const char nop3
[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5859 const char nop4
[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
5861 const char nop5
[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
5863 const char nop6
[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
5864 '\x44', '\x00', '\x00' };
5865 const char nop7
[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
5866 '\x00', '\x00', '\x00',
5868 const char nop8
[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
5869 '\x00', '\x00', '\x00',
5871 const char nop9
[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
5872 '\x84', '\x00', '\x00',
5873 '\x00', '\x00', '\x00' };
5874 const char nop10
[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5875 '\x1f', '\x84', '\x00',
5876 '\x00', '\x00', '\x00',
5878 const char nop11
[11] = { '\x66', '\x66', '\x2e', // data16
5879 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5880 '\x00', '\x00', '\x00',
5882 const char nop12
[12] = { '\x66', '\x66', '\x66', // data16; data16
5883 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5884 '\x84', '\x00', '\x00',
5885 '\x00', '\x00', '\x00' };
5886 const char nop13
[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5887 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5888 '\x1f', '\x84', '\x00',
5889 '\x00', '\x00', '\x00',
5891 const char nop14
[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5892 '\x66', '\x66', '\x2e', // data16
5893 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5894 '\x00', '\x00', '\x00',
5896 const char nop15
[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5897 '\x66', '\x66', '\x66', // data16; data16
5898 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5899 '\x84', '\x00', '\x00',
5900 '\x00', '\x00', '\x00' };
5902 const char* nops
[16] = {
5904 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
5905 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
5908 return std::string(nops
[length
], length
);
5911 // Return the addend to use for a target specific relocation. The
5912 // only target specific relocation is R_X86_64_TLSDESC for a local
5913 // symbol. We want to set the addend is the offset of the local
5914 // symbol in the TLS segment.
5918 Target_x86_64
<size
>::do_reloc_addend(void* arg
, unsigned int r_type
,
5921 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
5922 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
5923 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
5924 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
5925 const Symbol_value
<size
>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
5926 gold_assert(psymval
->is_tls_symbol());
5927 // The value of a TLS symbol is the offset in the TLS segment.
5928 return psymval
->value(ti
.object
, 0);
5931 // Return the value to use for the base of a DW_EH_PE_datarel offset
5932 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
5933 // assembler can not write out the difference between two labels in
5934 // different sections, so instead of using a pc-relative value they
5935 // use an offset from the GOT.
5939 Target_x86_64
<size
>::do_ehframe_datarel_base() const
5941 gold_assert(this->global_offset_table_
!= NULL
);
5942 Symbol
* sym
= this->global_offset_table_
;
5943 Sized_symbol
<size
>* ssym
= static_cast<Sized_symbol
<size
>*>(sym
);
5944 return ssym
->value();
5947 // FNOFFSET in section SHNDX in OBJECT is the start of a function
5948 // compiled with -fsplit-stack. The function calls non-split-stack
5949 // code. We have to change the function so that it always ensures
5950 // that it has enough stack space to run some random function.
5952 static const unsigned char cmp_insn_32
[] = { 0x64, 0x3b, 0x24, 0x25 };
5953 static const unsigned char lea_r10_insn_32
[] = { 0x44, 0x8d, 0x94, 0x24 };
5954 static const unsigned char lea_r11_insn_32
[] = { 0x44, 0x8d, 0x9c, 0x24 };
5956 static const unsigned char cmp_insn_64
[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
5957 static const unsigned char lea_r10_insn_64
[] = { 0x4c, 0x8d, 0x94, 0x24 };
5958 static const unsigned char lea_r11_insn_64
[] = { 0x4c, 0x8d, 0x9c, 0x24 };
5962 Target_x86_64
<size
>::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
5963 section_offset_type fnoffset
,
5964 section_size_type fnsize
,
5965 const unsigned char*,
5967 unsigned char* view
,
5968 section_size_type view_size
,
5970 std::string
* to
) const
5972 const char* const cmp_insn
= reinterpret_cast<const char*>
5973 (size
== 32 ? cmp_insn_32
: cmp_insn_64
);
5974 const char* const lea_r10_insn
= reinterpret_cast<const char*>
5975 (size
== 32 ? lea_r10_insn_32
: lea_r10_insn_64
);
5976 const char* const lea_r11_insn
= reinterpret_cast<const char*>
5977 (size
== 32 ? lea_r11_insn_32
: lea_r11_insn_64
);
5979 const size_t cmp_insn_len
=
5980 (size
== 32 ? sizeof(cmp_insn_32
) : sizeof(cmp_insn_64
));
5981 const size_t lea_r10_insn_len
=
5982 (size
== 32 ? sizeof(lea_r10_insn_32
) : sizeof(lea_r10_insn_64
));
5983 const size_t lea_r11_insn_len
=
5984 (size
== 32 ? sizeof(lea_r11_insn_32
) : sizeof(lea_r11_insn_64
));
5985 const size_t nop_len
= (size
== 32 ? 7 : 8);
5987 // The function starts with a comparison of the stack pointer and a
5988 // field in the TCB. This is followed by a jump.
5991 if (this->match_view(view
, view_size
, fnoffset
, cmp_insn
, cmp_insn_len
)
5992 && fnsize
> nop_len
+ 1)
5994 // We will call __morestack if the carry flag is set after this
5995 // comparison. We turn the comparison into an stc instruction
5997 view
[fnoffset
] = '\xf9';
5998 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, nop_len
);
6000 // lea NN(%rsp),%r10
6001 // lea NN(%rsp),%r11
6002 else if ((this->match_view(view
, view_size
, fnoffset
,
6003 lea_r10_insn
, lea_r10_insn_len
)
6004 || this->match_view(view
, view_size
, fnoffset
,
6005 lea_r11_insn
, lea_r11_insn_len
))
6008 // This is loading an offset from the stack pointer for a
6009 // comparison. The offset is negative, so we decrease the
6010 // offset by the amount of space we need for the stack. This
6011 // means we will avoid calling __morestack if there happens to
6012 // be plenty of space on the stack already.
6013 unsigned char* pval
= view
+ fnoffset
+ 4;
6014 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
6015 val
-= parameters
->options().split_stack_adjust_size();
6016 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
6020 if (!object
->has_no_split_stack())
6021 object
->error(_("failed to match split-stack sequence at "
6022 "section %u offset %0zx"),
6023 shndx
, static_cast<size_t>(fnoffset
));
6027 // We have to change the function so that it calls
6028 // __morestack_non_split instead of __morestack. The former will
6029 // allocate additional stack space.
6030 *from
= "__morestack";
6031 *to
= "__morestack_non_split";
6034 // The selector for x86_64 object files. Note this is never instantiated
6035 // directly. It's only used in Target_selector_x86_64_nacl, below.
6038 class Target_selector_x86_64
: public Target_selector_freebsd
6041 Target_selector_x86_64()
6042 : Target_selector_freebsd(elfcpp::EM_X86_64
, size
, false,
6044 ? "elf64-x86-64" : "elf32-x86-64"),
6046 ? "elf64-x86-64-freebsd"
6047 : "elf32-x86-64-freebsd"),
6048 (size
== 64 ? "elf_x86_64" : "elf32_x86_64"))
6052 do_instantiate_target()
6053 { return new Target_x86_64
<size
>(); }
6057 // NaCl variant. It uses different PLT contents.
6060 class Output_data_plt_x86_64_nacl
: public Output_data_plt_x86_64
<size
>
6063 Output_data_plt_x86_64_nacl(Layout
* layout
,
6064 Output_data_got
<64, false>* got
,
6065 Output_data_got_plt_x86_64
* got_plt
,
6066 Output_data_space
* got_irelative
)
6067 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
6068 got
, got_plt
, got_irelative
)
6071 Output_data_plt_x86_64_nacl(Layout
* layout
,
6072 Output_data_got
<64, false>* got
,
6073 Output_data_got_plt_x86_64
* got_plt
,
6074 Output_data_space
* got_irelative
,
6075 unsigned int plt_count
)
6076 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
6077 got
, got_plt
, got_irelative
,
6082 virtual unsigned int
6083 do_get_plt_entry_size() const
6084 { return plt_entry_size
; }
6087 do_add_eh_frame(Layout
* layout
)
6089 layout
->add_eh_frame_for_plt(this,
6090 this->plt_eh_frame_cie
,
6091 this->plt_eh_frame_cie_size
,
6093 plt_eh_frame_fde_size
);
6097 do_fill_first_plt_entry(unsigned char* pov
,
6098 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
6099 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
6101 virtual unsigned int
6102 do_fill_plt_entry(unsigned char* pov
,
6103 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6104 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6105 unsigned int got_offset
,
6106 unsigned int plt_offset
,
6107 unsigned int plt_index
);
6110 do_fill_tlsdesc_entry(unsigned char* pov
,
6111 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6112 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6113 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
6114 unsigned int tlsdesc_got_offset
,
6115 unsigned int plt_offset
);
6118 // The size of an entry in the PLT.
6119 static const int plt_entry_size
= 64;
6121 // The first entry in the PLT.
6122 static const unsigned char first_plt_entry
[plt_entry_size
];
6124 // Other entries in the PLT for an executable.
6125 static const unsigned char plt_entry
[plt_entry_size
];
6127 // The reserved TLSDESC entry in the PLT for an executable.
6128 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
6130 // The .eh_frame unwind information for the PLT.
6131 static const int plt_eh_frame_fde_size
= 32;
6132 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
6136 class Target_x86_64_nacl
: public Target_x86_64
<size
>
6139 Target_x86_64_nacl()
6140 : Target_x86_64
<size
>(&x86_64_nacl_info
)
6143 virtual Output_data_plt_x86_64
<size
>*
6144 do_make_data_plt(Layout
* layout
,
6145 Output_data_got
<64, false>* got
,
6146 Output_data_got_plt_x86_64
* got_plt
,
6147 Output_data_space
* got_irelative
)
6149 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
6153 virtual Output_data_plt_x86_64
<size
>*
6154 do_make_data_plt(Layout
* layout
,
6155 Output_data_got
<64, false>* got
,
6156 Output_data_got_plt_x86_64
* got_plt
,
6157 Output_data_space
* got_irelative
,
6158 unsigned int plt_count
)
6160 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
6166 do_code_fill(section_size_type length
) const;
6169 static const Target::Target_info x86_64_nacl_info
;
6173 const Target::Target_info Target_x86_64_nacl
<64>::x86_64_nacl_info
=
6176 false, // is_big_endian
6177 elfcpp::EM_X86_64
, // machine_code
6178 false, // has_make_symbol
6179 false, // has_resolve
6180 true, // has_code_fill
6181 true, // is_default_stack_executable
6182 true, // can_icf_inline_merge_sections
6184 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
6185 0x20000, // default_text_segment_address
6186 0x10000, // abi_pagesize (overridable by -z max-page-size)
6187 0x10000, // common_pagesize (overridable by -z common-page-size)
6188 true, // isolate_execinstr
6189 0x10000000, // rosegment_gap
6190 elfcpp::SHN_UNDEF
, // small_common_shndx
6191 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
6192 0, // small_common_section_flags
6193 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
6194 NULL
, // attributes_section
6195 NULL
, // attributes_vendor
6196 "_start", // entry_symbol_name
6197 32, // hash_entry_size
6198 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
6202 const Target::Target_info Target_x86_64_nacl
<32>::x86_64_nacl_info
=
6205 false, // is_big_endian
6206 elfcpp::EM_X86_64
, // machine_code
6207 false, // has_make_symbol
6208 false, // has_resolve
6209 true, // has_code_fill
6210 true, // is_default_stack_executable
6211 true, // can_icf_inline_merge_sections
6213 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
6214 0x20000, // default_text_segment_address
6215 0x10000, // abi_pagesize (overridable by -z max-page-size)
6216 0x10000, // common_pagesize (overridable by -z common-page-size)
6217 true, // isolate_execinstr
6218 0x10000000, // rosegment_gap
6219 elfcpp::SHN_UNDEF
, // small_common_shndx
6220 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
6221 0, // small_common_section_flags
6222 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
6223 NULL
, // attributes_section
6224 NULL
, // attributes_vendor
6225 "_start", // entry_symbol_name
6226 32, // hash_entry_size
6227 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
6230 #define NACLMASK 0xe0 // 32-byte alignment mask.
6232 // The first entry in the PLT.
6236 Output_data_plt_x86_64_nacl
<size
>::first_plt_entry
[plt_entry_size
] =
6238 0xff, 0x35, // pushq contents of memory address
6239 0, 0, 0, 0, // replaced with address of .got + 8
6240 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
6241 0, 0, 0, 0, // replaced with address of .got + 16
6242 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
6243 0x4d, 0x01, 0xfb, // add %r15, %r11
6244 0x41, 0xff, 0xe3, // jmpq *%r11
6246 // 9-byte nop sequence to pad out to the next 32-byte boundary.
6247 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
6249 // 32 bytes of nop to pad out to the standard size
6250 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6251 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6252 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6253 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6254 0x66, // excess data32 prefix
6260 Output_data_plt_x86_64_nacl
<size
>::do_fill_first_plt_entry(
6262 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6263 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
6265 memcpy(pov
, first_plt_entry
, plt_entry_size
);
6266 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
6268 - (plt_address
+ 2 + 4)));
6269 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
6271 - (plt_address
+ 9 + 4)));
6274 // Subsequent entries in the PLT.
6278 Output_data_plt_x86_64_nacl
<size
>::plt_entry
[plt_entry_size
] =
6280 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
6281 0, 0, 0, 0, // replaced with address of symbol in .got
6282 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
6283 0x4d, 0x01, 0xfb, // add %r15, %r11
6284 0x41, 0xff, 0xe3, // jmpq *%r11
6286 // 15-byte nop sequence to pad out to the next 32-byte boundary.
6287 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6288 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6290 // Lazy GOT entries point here (32-byte aligned).
6291 0x68, // pushq immediate
6292 0, 0, 0, 0, // replaced with index into relocation table
6293 0xe9, // jmp relative
6294 0, 0, 0, 0, // replaced with offset to start of .plt0
6296 // 22 bytes of nop to pad out to the standard size.
6297 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6298 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6299 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
6304 Output_data_plt_x86_64_nacl
<size
>::do_fill_plt_entry(
6306 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6307 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6308 unsigned int got_offset
,
6309 unsigned int plt_offset
,
6310 unsigned int plt_index
)
6312 memcpy(pov
, plt_entry
, plt_entry_size
);
6313 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3,
6314 (got_address
+ got_offset
6315 - (plt_address
+ plt_offset
6318 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_index
);
6319 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 38,
6320 - (plt_offset
+ 38 + 4));
6325 // The reserved TLSDESC entry in the PLT.
6329 Output_data_plt_x86_64_nacl
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
6331 0xff, 0x35, // pushq x(%rip)
6332 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
6333 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
6334 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
6335 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
6336 0x4d, 0x01, 0xfb, // add %r15, %r11
6337 0x41, 0xff, 0xe3, // jmpq *%r11
6339 // 41 bytes of nop to pad out to the standard size.
6340 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6341 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6342 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6343 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6344 0x66, 0x66, // excess data32 prefixes
6345 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6350 Output_data_plt_x86_64_nacl
<size
>::do_fill_tlsdesc_entry(
6352 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6353 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6354 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
6355 unsigned int tlsdesc_got_offset
,
6356 unsigned int plt_offset
)
6358 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
6359 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
6361 - (plt_address
+ plt_offset
6363 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
6365 + tlsdesc_got_offset
6366 - (plt_address
+ plt_offset
6370 // The .eh_frame unwind information for the PLT.
6374 Output_data_plt_x86_64_nacl
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
6376 0, 0, 0, 0, // Replaced with offset to .plt.
6377 0, 0, 0, 0, // Replaced with size of .plt.
6378 0, // Augmentation size.
6379 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
6380 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
6381 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
6382 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
6383 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
6384 13, // Block length.
6385 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
6386 elfcpp::DW_OP_breg16
, 0, // Push %rip.
6387 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
6388 elfcpp::DW_OP_and
, // & (%rip & 0x3f).
6389 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
6390 elfcpp::DW_OP_ge
, // >= ((%rip & 0x3f) >= 0x25)
6391 elfcpp::DW_OP_lit3
, // Push 3.
6392 elfcpp::DW_OP_shl
, // << (((%rip & 0x3f) >= 0x25) << 3)
6393 elfcpp::DW_OP_plus
, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
6394 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
6398 // Return a string used to fill a code section with nops.
6399 // For NaCl, long NOPs are only valid if they do not cross
6400 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
6403 Target_x86_64_nacl
<size
>::do_code_fill(section_size_type length
) const
6405 return std::string(length
, static_cast<char>(0x90));
6408 // The selector for x86_64-nacl object files.
6411 class Target_selector_x86_64_nacl
6412 : public Target_selector_nacl
<Target_selector_x86_64
<size
>,
6413 Target_x86_64_nacl
<size
> >
6416 Target_selector_x86_64_nacl()
6417 : Target_selector_nacl
<Target_selector_x86_64
<size
>,
6418 Target_x86_64_nacl
<size
> >("x86-64",
6420 ? "elf64-x86-64-nacl"
6421 : "elf32-x86-64-nacl",
6424 : "elf32_x86_64_nacl")
6428 Target_selector_x86_64_nacl
<64> target_selector_x86_64
;
6429 Target_selector_x86_64_nacl
<32> target_selector_x32
;
6431 } // End anonymous namespace.