1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright (C) 2006-2016 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 // Return the number of PLT entries.
185 { return this->count_
+ this->irelative_count_
; }
187 // Return the offset of the first non-reserved PLT entry.
189 first_plt_entry_offset()
190 { return this->get_plt_entry_size(); }
192 // Return the size of a PLT entry.
194 get_plt_entry_size() const
195 { return this->do_get_plt_entry_size(); }
197 // Reserve a slot in the PLT for an existing symbol in an incremental update.
199 reserve_slot(unsigned int plt_index
)
201 this->free_list_
.remove((plt_index
+ 1) * this->get_plt_entry_size(),
202 (plt_index
+ 2) * this->get_plt_entry_size());
205 // Return the PLT address to use for a global symbol.
207 address_for_global(const Symbol
*);
209 // Return the PLT address to use for a local symbol.
211 address_for_local(const Relobj
*, unsigned int symndx
);
213 // Add .eh_frame information for the PLT.
215 add_eh_frame(Layout
* layout
)
216 { this->do_add_eh_frame(layout
); }
219 // Fill in the first PLT entry.
221 fill_first_plt_entry(unsigned char* pov
,
222 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
223 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
224 { this->do_fill_first_plt_entry(pov
, got_address
, plt_address
); }
226 // Fill in a normal PLT entry. Returns the offset into the entry that
227 // should be the initial GOT slot value.
229 fill_plt_entry(unsigned char* pov
,
230 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
231 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
232 unsigned int got_offset
,
233 unsigned int plt_offset
,
234 unsigned int plt_index
)
236 return this->do_fill_plt_entry(pov
, got_address
, plt_address
,
237 got_offset
, plt_offset
, plt_index
);
240 // Fill in the reserved TLSDESC PLT entry.
242 fill_tlsdesc_entry(unsigned char* pov
,
243 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
244 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
245 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
246 unsigned int tlsdesc_got_offset
,
247 unsigned int plt_offset
)
249 this->do_fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
250 tlsdesc_got_offset
, plt_offset
);
254 do_get_plt_entry_size() const = 0;
257 do_fill_first_plt_entry(unsigned char* pov
,
258 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
259 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
)
263 do_fill_plt_entry(unsigned char* pov
,
264 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
265 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
266 unsigned int got_offset
,
267 unsigned int plt_offset
,
268 unsigned int plt_index
) = 0;
271 do_fill_tlsdesc_entry(unsigned char* pov
,
272 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
273 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
274 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
275 unsigned int tlsdesc_got_offset
,
276 unsigned int plt_offset
) = 0;
279 do_add_eh_frame(Layout
* layout
) = 0;
282 do_adjust_output_section(Output_section
* os
);
284 // Write to a map file.
286 do_print_to_mapfile(Mapfile
* mapfile
) const
287 { mapfile
->print_output_data(this, _("** PLT")); }
289 // The CIE of the .eh_frame unwind information for the PLT.
290 static const int plt_eh_frame_cie_size
= 16;
291 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
294 // Set the final size.
296 set_final_data_size();
298 // Write out the PLT data.
300 do_write(Output_file
*);
302 // The reloc section.
304 // The TLSDESC relocs, if necessary. These must follow the regular
306 Reloc_section
* tlsdesc_rel_
;
307 // The IRELATIVE relocs, if necessary. These must follow the
308 // regular PLT relocations and the TLSDESC relocations.
309 Reloc_section
* irelative_rel_
;
311 Output_data_got
<64, false>* got_
;
312 // The .got.plt section.
313 Output_data_got_plt_x86_64
* got_plt_
;
314 // The part of the .got.plt section used for IRELATIVE relocs.
315 Output_data_space
* got_irelative_
;
316 // The number of PLT entries.
318 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
319 // follow the regular PLT entries.
320 unsigned int irelative_count_
;
321 // Offset of the reserved TLSDESC_GOT entry when needed.
322 unsigned int tlsdesc_got_offset_
;
323 // List of available regions within the section, for incremental
325 Free_list free_list_
;
329 class Output_data_plt_x86_64_standard
: public Output_data_plt_x86_64
<size
>
332 Output_data_plt_x86_64_standard(Layout
* layout
,
333 Output_data_got
<64, false>* got
,
334 Output_data_got_plt_x86_64
* got_plt
,
335 Output_data_space
* got_irelative
)
336 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
337 got
, got_plt
, got_irelative
)
340 Output_data_plt_x86_64_standard(Layout
* layout
,
341 Output_data_got
<64, false>* got
,
342 Output_data_got_plt_x86_64
* got_plt
,
343 Output_data_space
* got_irelative
,
344 unsigned int plt_count
)
345 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
346 got
, got_plt
, got_irelative
,
352 do_get_plt_entry_size() const
353 { return plt_entry_size
; }
356 do_add_eh_frame(Layout
* layout
)
358 layout
->add_eh_frame_for_plt(this,
359 this->plt_eh_frame_cie
,
360 this->plt_eh_frame_cie_size
,
362 plt_eh_frame_fde_size
);
366 do_fill_first_plt_entry(unsigned char* pov
,
367 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
368 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
371 do_fill_plt_entry(unsigned char* pov
,
372 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
373 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
374 unsigned int got_offset
,
375 unsigned int plt_offset
,
376 unsigned int plt_index
);
379 do_fill_tlsdesc_entry(unsigned char* pov
,
380 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
381 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
382 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
383 unsigned int tlsdesc_got_offset
,
384 unsigned int plt_offset
);
387 // The size of an entry in the PLT.
388 static const int plt_entry_size
= 16;
390 // The first entry in the PLT.
391 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
392 // procedure linkage table for both programs and shared objects."
393 static const unsigned char first_plt_entry
[plt_entry_size
];
395 // Other entries in the PLT for an executable.
396 static const unsigned char plt_entry
[plt_entry_size
];
398 // The reserved TLSDESC entry in the PLT for an executable.
399 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
401 // The .eh_frame unwind information for the PLT.
402 static const int plt_eh_frame_fde_size
= 32;
403 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
406 // The x86_64 target class.
408 // http://www.x86-64.org/documentation/abi.pdf
409 // TLS info comes from
410 // http://people.redhat.com/drepper/tls.pdf
411 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
414 class Target_x86_64
: public Sized_target
<size
, false>
417 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
418 // uses only Elf64_Rela relocation entries with explicit addends."
419 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, size
, false> Reloc_section
;
421 Target_x86_64(const Target::Target_info
* info
= &x86_64_info
)
422 : Sized_target
<size
, false>(info
),
423 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
424 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rela_dyn_(NULL
),
425 rela_irelative_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
),
426 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
427 tls_base_symbol_defined_(false)
430 // Hook for a new output section.
432 do_new_output_section(Output_section
*) const;
434 // Scan the relocations to look for symbol adjustments.
436 gc_process_relocs(Symbol_table
* symtab
,
438 Sized_relobj_file
<size
, false>* object
,
439 unsigned int data_shndx
,
440 unsigned int sh_type
,
441 const unsigned char* prelocs
,
443 Output_section
* output_section
,
444 bool needs_special_offset_handling
,
445 size_t local_symbol_count
,
446 const unsigned char* plocal_symbols
);
448 // Scan the relocations to look for symbol adjustments.
450 scan_relocs(Symbol_table
* symtab
,
452 Sized_relobj_file
<size
, false>* object
,
453 unsigned int data_shndx
,
454 unsigned int sh_type
,
455 const unsigned char* prelocs
,
457 Output_section
* output_section
,
458 bool needs_special_offset_handling
,
459 size_t local_symbol_count
,
460 const unsigned char* plocal_symbols
);
462 // Finalize the sections.
464 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
466 // Return the value to use for a dynamic which requires special
469 do_dynsym_value(const Symbol
*) const;
471 // Relocate a section.
473 relocate_section(const Relocate_info
<size
, false>*,
474 unsigned int sh_type
,
475 const unsigned char* prelocs
,
477 Output_section
* output_section
,
478 bool needs_special_offset_handling
,
480 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
481 section_size_type view_size
,
482 const Reloc_symbol_changes
*);
484 // Scan the relocs during a relocatable link.
486 scan_relocatable_relocs(Symbol_table
* symtab
,
488 Sized_relobj_file
<size
, false>* object
,
489 unsigned int data_shndx
,
490 unsigned int sh_type
,
491 const unsigned char* prelocs
,
493 Output_section
* output_section
,
494 bool needs_special_offset_handling
,
495 size_t local_symbol_count
,
496 const unsigned char* plocal_symbols
,
497 Relocatable_relocs
*);
499 // Scan the relocs for --emit-relocs.
501 emit_relocs_scan(Symbol_table
* symtab
,
503 Sized_relobj_file
<size
, false>* object
,
504 unsigned int data_shndx
,
505 unsigned int sh_type
,
506 const unsigned char* prelocs
,
508 Output_section
* output_section
,
509 bool needs_special_offset_handling
,
510 size_t local_symbol_count
,
511 const unsigned char* plocal_syms
,
512 Relocatable_relocs
* rr
);
514 // Emit relocations for a section.
517 const Relocate_info
<size
, false>*,
518 unsigned int sh_type
,
519 const unsigned char* prelocs
,
521 Output_section
* output_section
,
522 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
524 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
525 section_size_type view_size
,
526 unsigned char* reloc_view
,
527 section_size_type reloc_view_size
);
529 // Return a string used to fill a code section with nops.
531 do_code_fill(section_size_type length
) const;
533 // Return whether SYM is defined by the ABI.
535 do_is_defined_by_abi(const Symbol
* sym
) const
536 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
538 // Return the symbol index to use for a target specific relocation.
539 // The only target specific relocation is R_X86_64_TLSDESC for a
540 // local symbol, which is an absolute reloc.
542 do_reloc_symbol_index(void*, unsigned int r_type
) const
544 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
548 // Return the addend to use for a target specific relocation.
550 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
552 // Return the PLT section.
554 do_plt_address_for_global(const Symbol
* gsym
) const
555 { return this->plt_section()->address_for_global(gsym
); }
558 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
559 { return this->plt_section()->address_for_local(relobj
, symndx
); }
561 // This function should be defined in targets that can use relocation
562 // types to determine (implemented in local_reloc_may_be_function_pointer
563 // and global_reloc_may_be_function_pointer)
564 // if a function's pointer is taken. ICF uses this in safe mode to only
565 // fold those functions whose pointer is defintely not taken. For x86_64
566 // pie binaries, safe ICF cannot be done by looking at relocation types.
568 do_can_check_for_function_pointers() const
569 { return !parameters
->options().pie(); }
571 // Return the base for a DW_EH_PE_datarel encoding.
573 do_ehframe_datarel_base() const;
575 // Adjust -fsplit-stack code which calls non-split-stack code.
577 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
578 section_offset_type fnoffset
, section_size_type fnsize
,
579 const unsigned char* prelocs
, size_t reloc_count
,
580 unsigned char* view
, section_size_type view_size
,
581 std::string
* from
, std::string
* to
) const;
583 // Return the size of the GOT section.
587 gold_assert(this->got_
!= NULL
);
588 return this->got_
->data_size();
591 // Return the number of entries in the GOT.
593 got_entry_count() const
595 if (this->got_
== NULL
)
597 return this->got_size() / 8;
600 // Return the number of entries in the PLT.
602 plt_entry_count() const;
604 // Return the offset of the first non-reserved PLT entry.
606 first_plt_entry_offset() const;
608 // Return the size of each PLT entry.
610 plt_entry_size() const;
612 // Return the size of each GOT entry.
614 got_entry_size() const
617 // Create the GOT section for an incremental update.
618 Output_data_got_base
*
619 init_got_plt_for_update(Symbol_table
* symtab
,
621 unsigned int got_count
,
622 unsigned int plt_count
);
624 // Reserve a GOT entry for a local symbol, and regenerate any
625 // necessary dynamic relocations.
627 reserve_local_got_entry(unsigned int got_index
,
628 Sized_relobj
<size
, false>* obj
,
630 unsigned int got_type
);
632 // Reserve a GOT entry for a global symbol, and regenerate any
633 // necessary dynamic relocations.
635 reserve_global_got_entry(unsigned int got_index
, Symbol
* gsym
,
636 unsigned int got_type
);
638 // Register an existing PLT entry for a global symbol.
640 register_global_plt_entry(Symbol_table
*, Layout
*, unsigned int plt_index
,
643 // Force a COPY relocation for a given symbol.
645 emit_copy_reloc(Symbol_table
*, Symbol
*, Output_section
*, off_t
);
647 // Apply an incremental relocation.
649 apply_relocation(const Relocate_info
<size
, false>* relinfo
,
650 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
652 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
655 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
656 section_size_type view_size
);
658 // Add a new reloc argument, returning the index in the vector.
660 add_tlsdesc_info(Sized_relobj_file
<size
, false>* object
, unsigned int r_sym
)
662 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
663 return this->tlsdesc_reloc_info_
.size() - 1;
666 Output_data_plt_x86_64
<size
>*
667 make_data_plt(Layout
* layout
,
668 Output_data_got
<64, false>* got
,
669 Output_data_got_plt_x86_64
* got_plt
,
670 Output_data_space
* got_irelative
)
672 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
);
675 Output_data_plt_x86_64
<size
>*
676 make_data_plt(Layout
* layout
,
677 Output_data_got
<64, false>* got
,
678 Output_data_got_plt_x86_64
* got_plt
,
679 Output_data_space
* got_irelative
,
680 unsigned int plt_count
)
682 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
,
686 virtual Output_data_plt_x86_64
<size
>*
687 do_make_data_plt(Layout
* layout
,
688 Output_data_got
<64, false>* got
,
689 Output_data_got_plt_x86_64
* got_plt
,
690 Output_data_space
* got_irelative
)
692 return new Output_data_plt_x86_64_standard
<size
>(layout
, got
, got_plt
,
696 virtual Output_data_plt_x86_64
<size
>*
697 do_make_data_plt(Layout
* layout
,
698 Output_data_got
<64, false>* got
,
699 Output_data_got_plt_x86_64
* got_plt
,
700 Output_data_space
* got_irelative
,
701 unsigned int plt_count
)
703 return new Output_data_plt_x86_64_standard
<size
>(layout
, got
, got_plt
,
709 // The class which scans relocations.
714 : issued_non_pic_error_(false)
718 get_reference_flags(unsigned int r_type
);
721 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
722 Sized_relobj_file
<size
, false>* object
,
723 unsigned int data_shndx
,
724 Output_section
* output_section
,
725 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
726 const elfcpp::Sym
<size
, false>& lsym
,
730 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
731 Sized_relobj_file
<size
, false>* object
,
732 unsigned int data_shndx
,
733 Output_section
* output_section
,
734 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
738 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
739 Target_x86_64
* target
,
740 Sized_relobj_file
<size
, false>* object
,
741 unsigned int data_shndx
,
742 Output_section
* output_section
,
743 const elfcpp::Rela
<size
, false>& reloc
,
745 const elfcpp::Sym
<size
, false>& lsym
);
748 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
749 Target_x86_64
* target
,
750 Sized_relobj_file
<size
, false>* object
,
751 unsigned int data_shndx
,
752 Output_section
* output_section
,
753 const elfcpp::Rela
<size
, false>& reloc
,
759 unsupported_reloc_local(Sized_relobj_file
<size
, false>*,
760 unsigned int r_type
);
763 unsupported_reloc_global(Sized_relobj_file
<size
, false>*,
764 unsigned int r_type
, Symbol
*);
767 check_non_pic(Relobj
*, unsigned int r_type
, Symbol
*);
770 possible_function_pointer_reloc(unsigned int r_type
);
773 reloc_needs_plt_for_ifunc(Sized_relobj_file
<size
, false>*,
774 unsigned int r_type
);
776 // Whether we have issued an error about a non-PIC compilation.
777 bool issued_non_pic_error_
;
780 // The class which implements relocation.
785 : skip_call_tls_get_addr_(false)
790 if (this->skip_call_tls_get_addr_
)
792 // FIXME: This needs to specify the location somehow.
793 gold_error(_("missing expected TLS relocation"));
797 // Do a relocation. Return false if the caller should not issue
798 // any warnings about this relocation.
800 relocate(const Relocate_info
<size
, false>*, unsigned int,
801 Target_x86_64
*, Output_section
*, size_t, const unsigned char*,
802 const Sized_symbol
<size
>*, const Symbol_value
<size
>*,
803 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
807 // Do a TLS relocation.
809 relocate_tls(const Relocate_info
<size
, false>*, Target_x86_64
*,
810 size_t relnum
, const elfcpp::Rela
<size
, false>&,
811 unsigned int r_type
, const Sized_symbol
<size
>*,
812 const Symbol_value
<size
>*,
813 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
816 // Do a TLS General-Dynamic to Initial-Exec transition.
818 tls_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
819 Output_segment
* tls_segment
,
820 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
821 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
823 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
824 section_size_type view_size
);
826 // Do a TLS General-Dynamic to Local-Exec transition.
828 tls_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
829 Output_segment
* tls_segment
,
830 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
831 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
833 section_size_type view_size
);
835 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
837 tls_desc_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
838 Output_segment
* tls_segment
,
839 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
840 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
842 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
843 section_size_type view_size
);
845 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
847 tls_desc_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
848 Output_segment
* tls_segment
,
849 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
850 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
852 section_size_type view_size
);
854 // Do a TLS Local-Dynamic to Local-Exec transition.
856 tls_ld_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
857 Output_segment
* tls_segment
,
858 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
859 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
861 section_size_type view_size
);
863 // Do a TLS Initial-Exec to Local-Exec transition.
865 tls_ie_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
866 Output_segment
* tls_segment
,
867 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
868 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
870 section_size_type view_size
);
872 // This is set if we should skip the next reloc, which should be a
873 // PLT32 reloc against ___tls_get_addr.
874 bool skip_call_tls_get_addr_
;
877 // Check if relocation against this symbol is a candidate for
879 // mov foo@GOTPCREL(%rip), %reg
880 // to lea foo(%rip), %reg.
882 can_convert_mov_to_lea(const Symbol
* gsym
)
884 gold_assert(gsym
!= NULL
);
885 return (gsym
->type() != elfcpp::STT_GNU_IFUNC
886 && !gsym
->is_undefined ()
887 && !gsym
->is_from_dynobj()
888 && !gsym
->is_preemptible()
889 && (!parameters
->options().shared()
890 || (gsym
->visibility() != elfcpp::STV_DEFAULT
891 && gsym
->visibility() != elfcpp::STV_PROTECTED
)
892 || parameters
->options().Bsymbolic())
893 && strcmp(gsym
->name(), "_DYNAMIC") != 0);
896 // Adjust TLS relocation type based on the options and whether this
897 // is a local symbol.
898 static tls::Tls_optimization
899 optimize_tls_reloc(bool is_final
, int r_type
);
901 // Get the GOT section, creating it if necessary.
902 Output_data_got
<64, false>*
903 got_section(Symbol_table
*, Layout
*);
905 // Get the GOT PLT section.
906 Output_data_got_plt_x86_64
*
907 got_plt_section() const
909 gold_assert(this->got_plt_
!= NULL
);
910 return this->got_plt_
;
913 // Get the GOT section for TLSDESC entries.
914 Output_data_got
<64, false>*
915 got_tlsdesc_section() const
917 gold_assert(this->got_tlsdesc_
!= NULL
);
918 return this->got_tlsdesc_
;
921 // Create the PLT section.
923 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
925 // Create a PLT entry for a global symbol.
927 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
929 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
931 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
932 Sized_relobj_file
<size
, false>* relobj
,
933 unsigned int local_sym_index
);
935 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
937 define_tls_base_symbol(Symbol_table
*, Layout
*);
939 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
941 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
943 // Create a GOT entry for the TLS module index.
945 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
946 Sized_relobj_file
<size
, false>* object
);
948 // Get the PLT section.
949 Output_data_plt_x86_64
<size
>*
952 gold_assert(this->plt_
!= NULL
);
956 // Get the dynamic reloc section, creating it if necessary.
958 rela_dyn_section(Layout
*);
960 // Get the section to use for TLSDESC relocations.
962 rela_tlsdesc_section(Layout
*) const;
964 // Get the section to use for IRELATIVE relocations.
966 rela_irelative_section(Layout
*);
968 // Add a potential copy relocation.
970 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
971 Sized_relobj_file
<size
, false>* object
,
972 unsigned int shndx
, Output_section
* output_section
,
973 Symbol
* sym
, const elfcpp::Rela
<size
, false>& reloc
)
975 unsigned int r_type
= elfcpp::elf_r_type
<size
>(reloc
.get_r_info());
976 this->copy_relocs_
.copy_reloc(symtab
, layout
,
977 symtab
->get_sized_symbol
<size
>(sym
),
978 object
, shndx
, output_section
,
979 r_type
, reloc
.get_r_offset(),
980 reloc
.get_r_addend(),
981 this->rela_dyn_section(layout
));
984 // Information about this specific target which we pass to the
985 // general Target structure.
986 static const Target::Target_info x86_64_info
;
988 // The types of GOT entries needed for this platform.
989 // These values are exposed to the ABI in an incremental link.
990 // Do not renumber existing values without changing the version
991 // number of the .gnu_incremental_inputs section.
994 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
995 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
996 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
997 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
1000 // This type is used as the argument to the target specific
1001 // relocation routines. The only target specific reloc is
1002 // R_X86_64_TLSDESC against a local symbol.
1005 Tlsdesc_info(Sized_relobj_file
<size
, false>* a_object
, unsigned int a_r_sym
)
1006 : object(a_object
), r_sym(a_r_sym
)
1009 // The object in which the local symbol is defined.
1010 Sized_relobj_file
<size
, false>* object
;
1011 // The local symbol index in the object.
1016 Output_data_got
<64, false>* got_
;
1018 Output_data_plt_x86_64
<size
>* plt_
;
1019 // The GOT PLT section.
1020 Output_data_got_plt_x86_64
* got_plt_
;
1021 // The GOT section for IRELATIVE relocations.
1022 Output_data_space
* got_irelative_
;
1023 // The GOT section for TLSDESC relocations.
1024 Output_data_got
<64, false>* got_tlsdesc_
;
1025 // The _GLOBAL_OFFSET_TABLE_ symbol.
1026 Symbol
* global_offset_table_
;
1027 // The dynamic reloc section.
1028 Reloc_section
* rela_dyn_
;
1029 // The section to use for IRELATIVE relocs.
1030 Reloc_section
* rela_irelative_
;
1031 // Relocs saved to avoid a COPY reloc.
1032 Copy_relocs
<elfcpp::SHT_RELA
, size
, false> copy_relocs_
;
1033 // Offset of the GOT entry for the TLS module index.
1034 unsigned int got_mod_index_offset_
;
1035 // We handle R_X86_64_TLSDESC against a local symbol as a target
1036 // specific relocation. Here we store the object and local symbol
1037 // index for the relocation.
1038 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
1039 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1040 bool tls_base_symbol_defined_
;
1044 const Target::Target_info Target_x86_64
<64>::x86_64_info
=
1047 false, // is_big_endian
1048 elfcpp::EM_X86_64
, // machine_code
1049 false, // has_make_symbol
1050 false, // has_resolve
1051 true, // has_code_fill
1052 true, // is_default_stack_executable
1053 true, // can_icf_inline_merge_sections
1055 "/lib/ld64.so.1", // program interpreter
1056 0x400000, // default_text_segment_address
1057 0x1000, // abi_pagesize (overridable by -z max-page-size)
1058 0x1000, // common_pagesize (overridable by -z common-page-size)
1059 false, // isolate_execinstr
1061 elfcpp::SHN_UNDEF
, // small_common_shndx
1062 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1063 0, // small_common_section_flags
1064 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1065 NULL
, // attributes_section
1066 NULL
, // attributes_vendor
1067 "_start", // entry_symbol_name
1068 32, // hash_entry_size
1072 const Target::Target_info Target_x86_64
<32>::x86_64_info
=
1075 false, // is_big_endian
1076 elfcpp::EM_X86_64
, // machine_code
1077 false, // has_make_symbol
1078 false, // has_resolve
1079 true, // has_code_fill
1080 true, // is_default_stack_executable
1081 true, // can_icf_inline_merge_sections
1083 "/libx32/ldx32.so.1", // program interpreter
1084 0x400000, // default_text_segment_address
1085 0x1000, // abi_pagesize (overridable by -z max-page-size)
1086 0x1000, // common_pagesize (overridable by -z common-page-size)
1087 false, // isolate_execinstr
1089 elfcpp::SHN_UNDEF
, // small_common_shndx
1090 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1091 0, // small_common_section_flags
1092 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1093 NULL
, // attributes_section
1094 NULL
, // attributes_vendor
1095 "_start", // entry_symbol_name
1096 32, // hash_entry_size
1099 // This is called when a new output section is created. This is where
1100 // we handle the SHF_X86_64_LARGE.
1104 Target_x86_64
<size
>::do_new_output_section(Output_section
* os
) const
1106 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
1107 os
->set_is_large_section();
1110 // Get the GOT section, creating it if necessary.
1113 Output_data_got
<64, false>*
1114 Target_x86_64
<size
>::got_section(Symbol_table
* symtab
, Layout
* layout
)
1116 if (this->got_
== NULL
)
1118 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
1120 // When using -z now, we can treat .got.plt as a relro section.
1121 // Without -z now, it is modified after program startup by lazy
1123 bool is_got_plt_relro
= parameters
->options().now();
1124 Output_section_order got_order
= (is_got_plt_relro
1126 : ORDER_RELRO_LAST
);
1127 Output_section_order got_plt_order
= (is_got_plt_relro
1129 : ORDER_NON_RELRO_FIRST
);
1131 this->got_
= new Output_data_got
<64, false>();
1133 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1135 | elfcpp::SHF_WRITE
),
1136 this->got_
, got_order
, true);
1138 this->got_plt_
= new Output_data_got_plt_x86_64(layout
);
1139 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1141 | elfcpp::SHF_WRITE
),
1142 this->got_plt_
, got_plt_order
,
1145 // The first three entries are reserved.
1146 this->got_plt_
->set_current_data_size(3 * 8);
1148 if (!is_got_plt_relro
)
1150 // Those bytes can go into the relro segment.
1151 layout
->increase_relro(3 * 8);
1154 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1155 this->global_offset_table_
=
1156 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1157 Symbol_table::PREDEFINED
,
1159 0, 0, elfcpp::STT_OBJECT
,
1161 elfcpp::STV_HIDDEN
, 0,
1164 // If there are any IRELATIVE relocations, they get GOT entries
1165 // in .got.plt after the jump slot entries.
1166 this->got_irelative_
= new Output_data_space(8, "** GOT IRELATIVE PLT");
1167 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1169 | elfcpp::SHF_WRITE
),
1170 this->got_irelative_
,
1171 got_plt_order
, is_got_plt_relro
);
1173 // If there are any TLSDESC relocations, they get GOT entries in
1174 // .got.plt after the jump slot and IRELATIVE entries.
1175 this->got_tlsdesc_
= new Output_data_got
<64, false>();
1176 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1178 | elfcpp::SHF_WRITE
),
1180 got_plt_order
, is_got_plt_relro
);
1186 // Get the dynamic reloc section, creating it if necessary.
1189 typename Target_x86_64
<size
>::Reloc_section
*
1190 Target_x86_64
<size
>::rela_dyn_section(Layout
* layout
)
1192 if (this->rela_dyn_
== NULL
)
1194 gold_assert(layout
!= NULL
);
1195 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
1196 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1197 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
1198 ORDER_DYNAMIC_RELOCS
, false);
1200 return this->rela_dyn_
;
1203 // Get the section to use for IRELATIVE relocs, creating it if
1204 // necessary. These go in .rela.dyn, but only after all other dynamic
1205 // relocations. They need to follow the other dynamic relocations so
1206 // that they can refer to global variables initialized by those
1210 typename Target_x86_64
<size
>::Reloc_section
*
1211 Target_x86_64
<size
>::rela_irelative_section(Layout
* layout
)
1213 if (this->rela_irelative_
== NULL
)
1215 // Make sure we have already created the dynamic reloc section.
1216 this->rela_dyn_section(layout
);
1217 this->rela_irelative_
= new Reloc_section(false);
1218 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1219 elfcpp::SHF_ALLOC
, this->rela_irelative_
,
1220 ORDER_DYNAMIC_RELOCS
, false);
1221 gold_assert(this->rela_dyn_
->output_section()
1222 == this->rela_irelative_
->output_section());
1224 return this->rela_irelative_
;
1227 // Write the first three reserved words of the .got.plt section.
1228 // The remainder of the section is written while writing the PLT
1229 // in Output_data_plt_i386::do_write.
1232 Output_data_got_plt_x86_64::do_write(Output_file
* of
)
1234 // The first entry in the GOT is the address of the .dynamic section
1235 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1236 // We saved space for them when we created the section in
1237 // Target_x86_64::got_section.
1238 const off_t got_file_offset
= this->offset();
1239 gold_assert(this->data_size() >= 24);
1240 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 24);
1241 Output_section
* dynamic
= this->layout_
->dynamic_section();
1242 uint64_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1243 elfcpp::Swap
<64, false>::writeval(got_view
, dynamic_addr
);
1244 memset(got_view
+ 8, 0, 16);
1245 of
->write_output_view(got_file_offset
, 24, got_view
);
1248 // Initialize the PLT section.
1252 Output_data_plt_x86_64
<size
>::init(Layout
* layout
)
1254 this->rel_
= new Reloc_section(false);
1255 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1256 elfcpp::SHF_ALLOC
, this->rel_
,
1257 ORDER_DYNAMIC_PLT_RELOCS
, false);
1262 Output_data_plt_x86_64
<size
>::do_adjust_output_section(Output_section
* os
)
1264 os
->set_entsize(this->get_plt_entry_size());
1267 // Add an entry to the PLT.
1271 Output_data_plt_x86_64
<size
>::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1274 gold_assert(!gsym
->has_plt_offset());
1276 unsigned int plt_index
;
1278 section_offset_type got_offset
;
1280 unsigned int* pcount
;
1281 unsigned int offset
;
1282 unsigned int reserved
;
1283 Output_section_data_build
* got
;
1284 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1285 && gsym
->can_use_relative_reloc(false))
1287 pcount
= &this->irelative_count_
;
1290 got
= this->got_irelative_
;
1294 pcount
= &this->count_
;
1297 got
= this->got_plt_
;
1300 if (!this->is_data_size_valid())
1302 // Note that when setting the PLT offset for a non-IRELATIVE
1303 // entry we skip the initial reserved PLT entry.
1304 plt_index
= *pcount
+ offset
;
1305 plt_offset
= plt_index
* this->get_plt_entry_size();
1309 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1310 gold_assert(got_offset
== got
->current_data_size());
1312 // Every PLT entry needs a GOT entry which points back to the PLT
1313 // entry (this will be changed by the dynamic linker, normally
1314 // lazily when the function is called).
1315 got
->set_current_data_size(got_offset
+ 8);
1319 // FIXME: This is probably not correct for IRELATIVE relocs.
1321 // For incremental updates, find an available slot.
1322 plt_offset
= this->free_list_
.allocate(this->get_plt_entry_size(),
1323 this->get_plt_entry_size(), 0);
1324 if (plt_offset
== -1)
1325 gold_fallback(_("out of patch space (PLT);"
1326 " relink with --incremental-full"));
1328 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1329 // can be calculated from the PLT index, adjusting for the three
1330 // reserved entries at the beginning of the GOT.
1331 plt_index
= plt_offset
/ this->get_plt_entry_size() - 1;
1332 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1335 gsym
->set_plt_offset(plt_offset
);
1337 // Every PLT entry needs a reloc.
1338 this->add_relocation(symtab
, layout
, gsym
, got_offset
);
1340 // Note that we don't need to save the symbol. The contents of the
1341 // PLT are independent of which symbols are used. The symbols only
1342 // appear in the relocations.
1345 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1350 Output_data_plt_x86_64
<size
>::add_local_ifunc_entry(
1351 Symbol_table
* symtab
,
1353 Sized_relobj_file
<size
, false>* relobj
,
1354 unsigned int local_sym_index
)
1356 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1357 ++this->irelative_count_
;
1359 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1361 // Every PLT entry needs a GOT entry which points back to the PLT
1363 this->got_irelative_
->set_current_data_size(got_offset
+ 8);
1365 // Every PLT entry needs a reloc.
1366 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1367 rela
->add_symbolless_local_addend(relobj
, local_sym_index
,
1368 elfcpp::R_X86_64_IRELATIVE
,
1369 this->got_irelative_
, got_offset
, 0);
1374 // Add the relocation for a PLT entry.
1378 Output_data_plt_x86_64
<size
>::add_relocation(Symbol_table
* symtab
,
1381 unsigned int got_offset
)
1383 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1384 && gsym
->can_use_relative_reloc(false))
1386 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1387 rela
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
1388 this->got_irelative_
, got_offset
, 0);
1392 gsym
->set_needs_dynsym_entry();
1393 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
1398 // Return where the TLSDESC relocations should go, creating it if
1399 // necessary. These follow the JUMP_SLOT relocations.
1402 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1403 Output_data_plt_x86_64
<size
>::rela_tlsdesc(Layout
* layout
)
1405 if (this->tlsdesc_rel_
== NULL
)
1407 this->tlsdesc_rel_
= new Reloc_section(false);
1408 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1409 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
1410 ORDER_DYNAMIC_PLT_RELOCS
, false);
1411 gold_assert(this->tlsdesc_rel_
->output_section()
1412 == this->rel_
->output_section());
1414 return this->tlsdesc_rel_
;
1417 // Return where the IRELATIVE relocations should go in the PLT. These
1418 // follow the JUMP_SLOT and the TLSDESC relocations.
1421 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1422 Output_data_plt_x86_64
<size
>::rela_irelative(Symbol_table
* symtab
,
1425 if (this->irelative_rel_
== NULL
)
1427 // Make sure we have a place for the TLSDESC relocations, in
1428 // case we see any later on.
1429 this->rela_tlsdesc(layout
);
1430 this->irelative_rel_
= new Reloc_section(false);
1431 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1432 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1433 ORDER_DYNAMIC_PLT_RELOCS
, false);
1434 gold_assert(this->irelative_rel_
->output_section()
1435 == this->rel_
->output_section());
1437 if (parameters
->doing_static_link())
1439 // A statically linked executable will only have a .rela.plt
1440 // section to hold R_X86_64_IRELATIVE relocs for
1441 // STT_GNU_IFUNC symbols. The library will use these
1442 // symbols to locate the IRELATIVE relocs at program startup
1444 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
1445 Symbol_table::PREDEFINED
,
1446 this->irelative_rel_
, 0, 0,
1447 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1448 elfcpp::STV_HIDDEN
, 0, false, true);
1449 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
1450 Symbol_table::PREDEFINED
,
1451 this->irelative_rel_
, 0, 0,
1452 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1453 elfcpp::STV_HIDDEN
, 0, true, true);
1456 return this->irelative_rel_
;
1459 // Return the PLT address to use for a global symbol.
1463 Output_data_plt_x86_64
<size
>::address_for_global(const Symbol
* gsym
)
1465 uint64_t offset
= 0;
1466 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1467 && gsym
->can_use_relative_reloc(false))
1468 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1469 return this->address() + offset
+ gsym
->plt_offset();
1472 // Return the PLT address to use for a local symbol. These are always
1473 // IRELATIVE relocs.
1477 Output_data_plt_x86_64
<size
>::address_for_local(const Relobj
* object
,
1480 return (this->address()
1481 + (this->count_
+ 1) * this->get_plt_entry_size()
1482 + object
->local_plt_offset(r_sym
));
1485 // Set the final size.
1488 Output_data_plt_x86_64
<size
>::set_final_data_size()
1490 unsigned int count
= this->count_
+ this->irelative_count_
;
1491 if (this->has_tlsdesc_entry())
1493 this->set_data_size((count
+ 1) * this->get_plt_entry_size());
1496 // The first entry in the PLT for an executable.
1500 Output_data_plt_x86_64_standard
<size
>::first_plt_entry
[plt_entry_size
] =
1502 // From AMD64 ABI Draft 0.98, page 76
1503 0xff, 0x35, // pushq contents of memory address
1504 0, 0, 0, 0, // replaced with address of .got + 8
1505 0xff, 0x25, // jmp indirect
1506 0, 0, 0, 0, // replaced with address of .got + 16
1507 0x90, 0x90, 0x90, 0x90 // noop (x4)
1512 Output_data_plt_x86_64_standard
<size
>::do_fill_first_plt_entry(
1514 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1515 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
1517 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1518 // We do a jmp relative to the PC at the end of this instruction.
1519 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1521 - (plt_address
+ 6)));
1522 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
1524 - (plt_address
+ 12)));
1527 // Subsequent entries in the PLT for an executable.
1531 Output_data_plt_x86_64_standard
<size
>::plt_entry
[plt_entry_size
] =
1533 // From AMD64 ABI Draft 0.98, page 76
1534 0xff, 0x25, // jmpq indirect
1535 0, 0, 0, 0, // replaced with address of symbol in .got
1536 0x68, // pushq immediate
1537 0, 0, 0, 0, // replaced with offset into relocation table
1538 0xe9, // jmpq relative
1539 0, 0, 0, 0 // replaced with offset to start of .plt
1544 Output_data_plt_x86_64_standard
<size
>::do_fill_plt_entry(
1546 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1547 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
1548 unsigned int got_offset
,
1549 unsigned int plt_offset
,
1550 unsigned int plt_index
)
1552 // Check PC-relative offset overflow in PLT entry.
1553 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
1554 - (plt_address
+ plt_offset
+ 6));
1555 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
1556 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1559 memcpy(pov
, plt_entry
, plt_entry_size
);
1560 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1561 plt_got_pcrel_offset
);
1563 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
1564 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
1565 - (plt_offset
+ plt_entry_size
));
1570 // The reserved TLSDESC entry in the PLT for an executable.
1574 Output_data_plt_x86_64_standard
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
1576 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1577 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1578 0xff, 0x35, // pushq x(%rip)
1579 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1580 0xff, 0x25, // jmpq *y(%rip)
1581 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1588 Output_data_plt_x86_64_standard
<size
>::do_fill_tlsdesc_entry(
1590 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1591 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
1592 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
1593 unsigned int tlsdesc_got_offset
,
1594 unsigned int plt_offset
)
1596 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1597 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1599 - (plt_address
+ plt_offset
1601 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
1603 + tlsdesc_got_offset
1604 - (plt_address
+ plt_offset
1608 // The .eh_frame unwind information for the PLT.
1612 Output_data_plt_x86_64
<size
>::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1615 'z', // Augmentation: augmentation size included.
1616 'R', // Augmentation: FDE encoding included.
1617 '\0', // End of augmentation string.
1618 1, // Code alignment factor.
1619 0x78, // Data alignment factor.
1620 16, // Return address column.
1621 1, // Augmentation size.
1622 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1623 | elfcpp::DW_EH_PE_sdata4
),
1624 elfcpp::DW_CFA_def_cfa
, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1625 elfcpp::DW_CFA_offset
+ 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1626 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1632 Output_data_plt_x86_64_standard
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1634 0, 0, 0, 0, // Replaced with offset to .plt.
1635 0, 0, 0, 0, // Replaced with size of .plt.
1636 0, // Augmentation size.
1637 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
1638 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1639 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
1640 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1641 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1642 11, // Block length.
1643 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
1644 elfcpp::DW_OP_breg16
, 0, // Push %rip.
1645 elfcpp::DW_OP_lit15
, // Push 0xf.
1646 elfcpp::DW_OP_and
, // & (%rip & 0xf).
1647 elfcpp::DW_OP_lit11
, // Push 0xb.
1648 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 0xb)
1649 elfcpp::DW_OP_lit3
, // Push 3.
1650 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 0xb) << 3)
1651 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1652 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1658 // Write out the PLT. This uses the hand-coded instructions above,
1659 // and adjusts them as needed. This is specified by the AMD64 ABI.
1663 Output_data_plt_x86_64
<size
>::do_write(Output_file
* of
)
1665 const off_t offset
= this->offset();
1666 const section_size_type oview_size
=
1667 convert_to_section_size_type(this->data_size());
1668 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1670 const off_t got_file_offset
= this->got_plt_
->offset();
1671 gold_assert(parameters
->incremental_update()
1672 || (got_file_offset
+ this->got_plt_
->data_size()
1673 == this->got_irelative_
->offset()));
1674 const section_size_type got_size
=
1675 convert_to_section_size_type(this->got_plt_
->data_size()
1676 + this->got_irelative_
->data_size());
1677 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1680 unsigned char* pov
= oview
;
1682 // The base address of the .plt section.
1683 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
= this->address();
1684 // The base address of the .got section.
1685 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
= this->got_
->address();
1686 // The base address of the PLT portion of the .got section,
1687 // which is where the GOT pointer will point, and where the
1688 // three reserved GOT entries are located.
1689 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
1690 = this->got_plt_
->address();
1692 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
1693 pov
+= this->get_plt_entry_size();
1695 // The first three entries in the GOT are reserved, and are written
1696 // by Output_data_got_plt_x86_64::do_write.
1697 unsigned char* got_pov
= got_view
+ 24;
1699 unsigned int plt_offset
= this->get_plt_entry_size();
1700 unsigned int got_offset
= 24;
1701 const unsigned int count
= this->count_
+ this->irelative_count_
;
1702 for (unsigned int plt_index
= 0;
1705 pov
+= this->get_plt_entry_size(),
1707 plt_offset
+= this->get_plt_entry_size(),
1710 // Set and adjust the PLT entry itself.
1711 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1712 got_address
, plt_address
,
1713 got_offset
, plt_offset
,
1716 // Set the entry in the GOT.
1717 elfcpp::Swap
<64, false>::writeval(got_pov
,
1718 plt_address
+ plt_offset
+ lazy_offset
);
1721 if (this->has_tlsdesc_entry())
1723 // Set and adjust the reserved TLSDESC PLT entry.
1724 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
1725 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
1726 tlsdesc_got_offset
, plt_offset
);
1727 pov
+= this->get_plt_entry_size();
1730 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1731 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1733 of
->write_output_view(offset
, oview_size
, oview
);
1734 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1737 // Create the PLT section.
1741 Target_x86_64
<size
>::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1743 if (this->plt_
== NULL
)
1745 // Create the GOT sections first.
1746 this->got_section(symtab
, layout
);
1748 this->plt_
= this->make_data_plt(layout
, this->got_
, this->got_plt_
,
1749 this->got_irelative_
);
1751 // Add unwind information if requested.
1752 if (parameters
->options().ld_generated_unwind_info())
1753 this->plt_
->add_eh_frame(layout
);
1755 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1757 | elfcpp::SHF_EXECINSTR
),
1758 this->plt_
, ORDER_PLT
, false);
1760 // Make the sh_info field of .rela.plt point to .plt.
1761 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1762 rela_plt_os
->set_info_section(this->plt_
->output_section());
1766 // Return the section for TLSDESC relocations.
1769 typename Target_x86_64
<size
>::Reloc_section
*
1770 Target_x86_64
<size
>::rela_tlsdesc_section(Layout
* layout
) const
1772 return this->plt_section()->rela_tlsdesc(layout
);
1775 // Create a PLT entry for a global symbol.
1779 Target_x86_64
<size
>::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1782 if (gsym
->has_plt_offset())
1785 if (this->plt_
== NULL
)
1786 this->make_plt_section(symtab
, layout
);
1788 this->plt_
->add_entry(symtab
, layout
, gsym
);
1791 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1795 Target_x86_64
<size
>::make_local_ifunc_plt_entry(
1796 Symbol_table
* symtab
, Layout
* layout
,
1797 Sized_relobj_file
<size
, false>* relobj
,
1798 unsigned int local_sym_index
)
1800 if (relobj
->local_has_plt_offset(local_sym_index
))
1802 if (this->plt_
== NULL
)
1803 this->make_plt_section(symtab
, layout
);
1804 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1807 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1810 // Return the number of entries in the PLT.
1814 Target_x86_64
<size
>::plt_entry_count() const
1816 if (this->plt_
== NULL
)
1818 return this->plt_
->entry_count();
1821 // Return the offset of the first non-reserved PLT entry.
1825 Target_x86_64
<size
>::first_plt_entry_offset() const
1827 return this->plt_
->first_plt_entry_offset();
1830 // Return the size of each PLT entry.
1834 Target_x86_64
<size
>::plt_entry_size() const
1836 return this->plt_
->get_plt_entry_size();
1839 // Create the GOT and PLT sections for an incremental update.
1842 Output_data_got_base
*
1843 Target_x86_64
<size
>::init_got_plt_for_update(Symbol_table
* symtab
,
1845 unsigned int got_count
,
1846 unsigned int plt_count
)
1848 gold_assert(this->got_
== NULL
);
1850 this->got_
= new Output_data_got
<64, false>(got_count
* 8);
1851 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1853 | elfcpp::SHF_WRITE
),
1854 this->got_
, ORDER_RELRO_LAST
,
1857 // Add the three reserved entries.
1858 this->got_plt_
= new Output_data_got_plt_x86_64(layout
, (plt_count
+ 3) * 8);
1859 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1861 | elfcpp::SHF_WRITE
),
1862 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
1865 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1866 this->global_offset_table_
=
1867 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1868 Symbol_table::PREDEFINED
,
1870 0, 0, elfcpp::STT_OBJECT
,
1872 elfcpp::STV_HIDDEN
, 0,
1875 // If there are any TLSDESC relocations, they get GOT entries in
1876 // .got.plt after the jump slot entries.
1877 // FIXME: Get the count for TLSDESC entries.
1878 this->got_tlsdesc_
= new Output_data_got
<64, false>(0);
1879 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1880 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
1882 ORDER_NON_RELRO_FIRST
, false);
1884 // If there are any IRELATIVE relocations, they get GOT entries in
1885 // .got.plt after the jump slot and TLSDESC entries.
1886 this->got_irelative_
= new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1887 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1888 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
1889 this->got_irelative_
,
1890 ORDER_NON_RELRO_FIRST
, false);
1892 // Create the PLT section.
1893 this->plt_
= this->make_data_plt(layout
, this->got_
,
1895 this->got_irelative_
,
1898 // Add unwind information if requested.
1899 if (parameters
->options().ld_generated_unwind_info())
1900 this->plt_
->add_eh_frame(layout
);
1902 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1903 elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
,
1904 this->plt_
, ORDER_PLT
, false);
1906 // Make the sh_info field of .rela.plt point to .plt.
1907 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1908 rela_plt_os
->set_info_section(this->plt_
->output_section());
1910 // Create the rela_dyn section.
1911 this->rela_dyn_section(layout
);
1916 // Reserve a GOT entry for a local symbol, and regenerate any
1917 // necessary dynamic relocations.
1921 Target_x86_64
<size
>::reserve_local_got_entry(
1922 unsigned int got_index
,
1923 Sized_relobj
<size
, false>* obj
,
1925 unsigned int got_type
)
1927 unsigned int got_offset
= got_index
* 8;
1928 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
1930 this->got_
->reserve_local(got_index
, obj
, r_sym
, got_type
);
1933 case GOT_TYPE_STANDARD
:
1934 if (parameters
->options().output_is_position_independent())
1935 rela_dyn
->add_local_relative(obj
, r_sym
, elfcpp::R_X86_64_RELATIVE
,
1936 this->got_
, got_offset
, 0, false);
1938 case GOT_TYPE_TLS_OFFSET
:
1939 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_TPOFF64
,
1940 this->got_
, got_offset
, 0);
1942 case GOT_TYPE_TLS_PAIR
:
1943 this->got_
->reserve_slot(got_index
+ 1);
1944 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_DTPMOD64
,
1945 this->got_
, got_offset
, 0);
1947 case GOT_TYPE_TLS_DESC
:
1948 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1949 // this->got_->reserve_slot(got_index + 1);
1950 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1951 // this->got_, got_offset, 0);
1958 // Reserve a GOT entry for a global symbol, and regenerate any
1959 // necessary dynamic relocations.
1963 Target_x86_64
<size
>::reserve_global_got_entry(unsigned int got_index
,
1965 unsigned int got_type
)
1967 unsigned int got_offset
= got_index
* 8;
1968 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
1970 this->got_
->reserve_global(got_index
, gsym
, got_type
);
1973 case GOT_TYPE_STANDARD
:
1974 if (!gsym
->final_value_is_known())
1976 if (gsym
->is_from_dynobj()
1977 || gsym
->is_undefined()
1978 || gsym
->is_preemptible()
1979 || gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1980 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
,
1981 this->got_
, got_offset
, 0);
1983 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1984 this->got_
, got_offset
, 0, false);
1987 case GOT_TYPE_TLS_OFFSET
:
1988 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TPOFF64
,
1989 this->got_
, got_offset
, 0, false);
1991 case GOT_TYPE_TLS_PAIR
:
1992 this->got_
->reserve_slot(got_index
+ 1);
1993 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPMOD64
,
1994 this->got_
, got_offset
, 0, false);
1995 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPOFF64
,
1996 this->got_
, got_offset
+ 8, 0, false);
1998 case GOT_TYPE_TLS_DESC
:
1999 this->got_
->reserve_slot(got_index
+ 1);
2000 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TLSDESC
,
2001 this->got_
, got_offset
, 0, false);
2008 // Register an existing PLT entry for a global symbol.
2012 Target_x86_64
<size
>::register_global_plt_entry(Symbol_table
* symtab
,
2014 unsigned int plt_index
,
2017 gold_assert(this->plt_
!= NULL
);
2018 gold_assert(!gsym
->has_plt_offset());
2020 this->plt_
->reserve_slot(plt_index
);
2022 gsym
->set_plt_offset((plt_index
+ 1) * this->plt_entry_size());
2024 unsigned int got_offset
= (plt_index
+ 3) * 8;
2025 this->plt_
->add_relocation(symtab
, layout
, gsym
, got_offset
);
2028 // Force a COPY relocation for a given symbol.
2032 Target_x86_64
<size
>::emit_copy_reloc(
2033 Symbol_table
* symtab
, Symbol
* sym
, Output_section
* os
, off_t offset
)
2035 this->copy_relocs_
.emit_copy_reloc(symtab
,
2036 symtab
->get_sized_symbol
<size
>(sym
),
2039 this->rela_dyn_section(NULL
));
2042 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2046 Target_x86_64
<size
>::define_tls_base_symbol(Symbol_table
* symtab
,
2049 if (this->tls_base_symbol_defined_
)
2052 Output_segment
* tls_segment
= layout
->tls_segment();
2053 if (tls_segment
!= NULL
)
2055 bool is_exec
= parameters
->options().output_is_executable();
2056 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
2057 Symbol_table::PREDEFINED
,
2061 elfcpp::STV_HIDDEN
, 0,
2063 ? Symbol::SEGMENT_END
2064 : Symbol::SEGMENT_START
),
2067 this->tls_base_symbol_defined_
= true;
2070 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2074 Target_x86_64
<size
>::reserve_tlsdesc_entries(Symbol_table
* symtab
,
2077 if (this->plt_
== NULL
)
2078 this->make_plt_section(symtab
, layout
);
2080 if (!this->plt_
->has_tlsdesc_entry())
2082 // Allocate the TLSDESC_GOT entry.
2083 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
2084 unsigned int got_offset
= got
->add_constant(0);
2086 // Allocate the TLSDESC_PLT entry.
2087 this->plt_
->reserve_tlsdesc_entry(got_offset
);
2091 // Create a GOT entry for the TLS module index.
2095 Target_x86_64
<size
>::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
2096 Sized_relobj_file
<size
, false>* object
)
2098 if (this->got_mod_index_offset_
== -1U)
2100 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
2101 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
2102 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
2103 unsigned int got_offset
= got
->add_constant(0);
2104 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
2106 got
->add_constant(0);
2107 this->got_mod_index_offset_
= got_offset
;
2109 return this->got_mod_index_offset_
;
2112 // Optimize the TLS relocation type based on what we know about the
2113 // symbol. IS_FINAL is true if the final address of this symbol is
2114 // known at link time.
2117 tls::Tls_optimization
2118 Target_x86_64
<size
>::optimize_tls_reloc(bool is_final
, int r_type
)
2120 // If we are generating a shared library, then we can't do anything
2122 if (parameters
->options().shared())
2123 return tls::TLSOPT_NONE
;
2127 case elfcpp::R_X86_64_TLSGD
:
2128 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2129 case elfcpp::R_X86_64_TLSDESC_CALL
:
2130 // These are General-Dynamic which permits fully general TLS
2131 // access. Since we know that we are generating an executable,
2132 // we can convert this to Initial-Exec. If we also know that
2133 // this is a local symbol, we can further switch to Local-Exec.
2135 return tls::TLSOPT_TO_LE
;
2136 return tls::TLSOPT_TO_IE
;
2138 case elfcpp::R_X86_64_TLSLD
:
2139 // This is Local-Dynamic, which refers to a local symbol in the
2140 // dynamic TLS block. Since we know that we generating an
2141 // executable, we can switch to Local-Exec.
2142 return tls::TLSOPT_TO_LE
;
2144 case elfcpp::R_X86_64_DTPOFF32
:
2145 case elfcpp::R_X86_64_DTPOFF64
:
2146 // Another Local-Dynamic reloc.
2147 return tls::TLSOPT_TO_LE
;
2149 case elfcpp::R_X86_64_GOTTPOFF
:
2150 // These are Initial-Exec relocs which get the thread offset
2151 // from the GOT. If we know that we are linking against the
2152 // local symbol, we can switch to Local-Exec, which links the
2153 // thread offset into the instruction.
2155 return tls::TLSOPT_TO_LE
;
2156 return tls::TLSOPT_NONE
;
2158 case elfcpp::R_X86_64_TPOFF32
:
2159 // When we already have Local-Exec, there is nothing further we
2161 return tls::TLSOPT_NONE
;
2168 // Get the Reference_flags for a particular relocation.
2172 Target_x86_64
<size
>::Scan::get_reference_flags(unsigned int r_type
)
2176 case elfcpp::R_X86_64_NONE
:
2177 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2178 case elfcpp::R_X86_64_GNU_VTENTRY
:
2179 case elfcpp::R_X86_64_GOTPC32
:
2180 case elfcpp::R_X86_64_GOTPC64
:
2181 // No symbol reference.
2184 case elfcpp::R_X86_64_64
:
2185 case elfcpp::R_X86_64_32
:
2186 case elfcpp::R_X86_64_32S
:
2187 case elfcpp::R_X86_64_16
:
2188 case elfcpp::R_X86_64_8
:
2189 return Symbol::ABSOLUTE_REF
;
2191 case elfcpp::R_X86_64_PC64
:
2192 case elfcpp::R_X86_64_PC32
:
2193 case elfcpp::R_X86_64_PC32_BND
:
2194 case elfcpp::R_X86_64_PC16
:
2195 case elfcpp::R_X86_64_PC8
:
2196 case elfcpp::R_X86_64_GOTOFF64
:
2197 return Symbol::RELATIVE_REF
;
2199 case elfcpp::R_X86_64_PLT32
:
2200 case elfcpp::R_X86_64_PLT32_BND
:
2201 case elfcpp::R_X86_64_PLTOFF64
:
2202 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
2204 case elfcpp::R_X86_64_GOT64
:
2205 case elfcpp::R_X86_64_GOT32
:
2206 case elfcpp::R_X86_64_GOTPCREL64
:
2207 case elfcpp::R_X86_64_GOTPCREL
:
2208 case elfcpp::R_X86_64_GOTPCRELX
:
2209 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2210 case elfcpp::R_X86_64_GOTPLT64
:
2212 return Symbol::ABSOLUTE_REF
;
2214 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2215 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2216 case elfcpp::R_X86_64_TLSDESC_CALL
:
2217 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2218 case elfcpp::R_X86_64_DTPOFF32
:
2219 case elfcpp::R_X86_64_DTPOFF64
:
2220 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2221 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2222 return Symbol::TLS_REF
;
2224 case elfcpp::R_X86_64_COPY
:
2225 case elfcpp::R_X86_64_GLOB_DAT
:
2226 case elfcpp::R_X86_64_JUMP_SLOT
:
2227 case elfcpp::R_X86_64_RELATIVE
:
2228 case elfcpp::R_X86_64_IRELATIVE
:
2229 case elfcpp::R_X86_64_TPOFF64
:
2230 case elfcpp::R_X86_64_DTPMOD64
:
2231 case elfcpp::R_X86_64_TLSDESC
:
2232 case elfcpp::R_X86_64_SIZE32
:
2233 case elfcpp::R_X86_64_SIZE64
:
2235 // Not expected. We will give an error later.
2240 // Report an unsupported relocation against a local symbol.
2244 Target_x86_64
<size
>::Scan::unsupported_reloc_local(
2245 Sized_relobj_file
<size
, false>* object
,
2246 unsigned int r_type
)
2248 gold_error(_("%s: unsupported reloc %u against local symbol"),
2249 object
->name().c_str(), r_type
);
2252 // We are about to emit a dynamic relocation of type R_TYPE. If the
2253 // dynamic linker does not support it, issue an error. The GNU linker
2254 // only issues a non-PIC error for an allocated read-only section.
2255 // Here we know the section is allocated, but we don't know that it is
2256 // read-only. But we check for all the relocation types which the
2257 // glibc dynamic linker supports, so it seems appropriate to issue an
2258 // error even if the section is not read-only. If GSYM is not NULL,
2259 // it is the symbol the relocation is against; if it is NULL, the
2260 // relocation is against a local symbol.
2264 Target_x86_64
<size
>::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
,
2269 // These are the relocation types supported by glibc for x86_64
2270 // which should always work.
2271 case elfcpp::R_X86_64_RELATIVE
:
2272 case elfcpp::R_X86_64_IRELATIVE
:
2273 case elfcpp::R_X86_64_GLOB_DAT
:
2274 case elfcpp::R_X86_64_JUMP_SLOT
:
2275 case elfcpp::R_X86_64_DTPMOD64
:
2276 case elfcpp::R_X86_64_DTPOFF64
:
2277 case elfcpp::R_X86_64_TPOFF64
:
2278 case elfcpp::R_X86_64_64
:
2279 case elfcpp::R_X86_64_COPY
:
2282 // glibc supports these reloc types, but they can overflow.
2283 case elfcpp::R_X86_64_PC32
:
2284 case elfcpp::R_X86_64_PC32_BND
:
2285 // A PC relative reference is OK against a local symbol or if
2286 // the symbol is defined locally.
2288 || (!gsym
->is_from_dynobj()
2289 && !gsym
->is_undefined()
2290 && !gsym
->is_preemptible()))
2293 case elfcpp::R_X86_64_32
:
2294 // R_X86_64_32 is OK for x32.
2295 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
2297 if (this->issued_non_pic_error_
)
2299 gold_assert(parameters
->options().output_is_position_independent());
2301 object
->error(_("requires dynamic R_X86_64_32 reloc which may "
2302 "overflow at runtime; recompile with -fPIC"));
2308 case elfcpp::R_X86_64_32
:
2309 r_name
= "R_X86_64_32";
2311 case elfcpp::R_X86_64_PC32
:
2312 r_name
= "R_X86_64_PC32";
2314 case elfcpp::R_X86_64_PC32_BND
:
2315 r_name
= "R_X86_64_PC32_BND";
2321 object
->error(_("requires dynamic %s reloc against '%s' "
2322 "which may overflow at runtime; recompile "
2324 r_name
, gsym
->name());
2326 this->issued_non_pic_error_
= true;
2330 // This prevents us from issuing more than one error per reloc
2331 // section. But we can still wind up issuing more than one
2332 // error per object file.
2333 if (this->issued_non_pic_error_
)
2335 gold_assert(parameters
->options().output_is_position_independent());
2336 object
->error(_("requires unsupported dynamic reloc %u; "
2337 "recompile with -fPIC"),
2339 this->issued_non_pic_error_
= true;
2342 case elfcpp::R_X86_64_NONE
:
2347 // Return whether we need to make a PLT entry for a relocation of the
2348 // given type against a STT_GNU_IFUNC symbol.
2352 Target_x86_64
<size
>::Scan::reloc_needs_plt_for_ifunc(
2353 Sized_relobj_file
<size
, false>* object
,
2354 unsigned int r_type
)
2356 int flags
= Scan::get_reference_flags(r_type
);
2357 if (flags
& Symbol::TLS_REF
)
2358 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2359 object
->name().c_str(), r_type
);
2363 // Scan a relocation for a local symbol.
2367 Target_x86_64
<size
>::Scan::local(Symbol_table
* symtab
,
2369 Target_x86_64
<size
>* target
,
2370 Sized_relobj_file
<size
, false>* object
,
2371 unsigned int data_shndx
,
2372 Output_section
* output_section
,
2373 const elfcpp::Rela
<size
, false>& reloc
,
2374 unsigned int r_type
,
2375 const elfcpp::Sym
<size
, false>& lsym
,
2381 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2382 bool is_ifunc
= lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
;
2383 if (is_ifunc
&& this->reloc_needs_plt_for_ifunc(object
, r_type
))
2385 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2386 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
2391 case elfcpp::R_X86_64_NONE
:
2392 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2393 case elfcpp::R_X86_64_GNU_VTENTRY
:
2396 case elfcpp::R_X86_64_64
:
2397 // If building a shared library (or a position-independent
2398 // executable), we need to create a dynamic relocation for this
2399 // location. The relocation applied at link time will apply the
2400 // link-time value, so we flag the location with an
2401 // R_X86_64_RELATIVE relocation so the dynamic loader can
2402 // relocate it easily.
2403 if (parameters
->options().output_is_position_independent())
2405 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2406 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2407 rela_dyn
->add_local_relative(object
, r_sym
,
2409 ? elfcpp::R_X86_64_RELATIVE64
2410 : elfcpp::R_X86_64_RELATIVE
),
2411 output_section
, data_shndx
,
2412 reloc
.get_r_offset(),
2413 reloc
.get_r_addend(), is_ifunc
);
2417 case elfcpp::R_X86_64_32
:
2418 case elfcpp::R_X86_64_32S
:
2419 case elfcpp::R_X86_64_16
:
2420 case elfcpp::R_X86_64_8
:
2421 // If building a shared library (or a position-independent
2422 // executable), we need to create a dynamic relocation for this
2423 // location. We can't use an R_X86_64_RELATIVE relocation
2424 // because that is always a 64-bit relocation.
2425 if (parameters
->options().output_is_position_independent())
2427 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2428 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
2430 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2431 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2432 rela_dyn
->add_local_relative(object
, r_sym
,
2433 elfcpp::R_X86_64_RELATIVE
,
2434 output_section
, data_shndx
,
2435 reloc
.get_r_offset(),
2436 reloc
.get_r_addend(), is_ifunc
);
2440 this->check_non_pic(object
, r_type
, NULL
);
2442 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2443 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2444 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
2445 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
2446 data_shndx
, reloc
.get_r_offset(),
2447 reloc
.get_r_addend());
2450 gold_assert(lsym
.get_st_value() == 0);
2451 unsigned int shndx
= lsym
.get_st_shndx();
2453 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
2456 object
->error(_("section symbol %u has bad shndx %u"),
2459 rela_dyn
->add_local_section(object
, shndx
,
2460 r_type
, output_section
,
2461 data_shndx
, reloc
.get_r_offset(),
2462 reloc
.get_r_addend());
2467 case elfcpp::R_X86_64_PC64
:
2468 case elfcpp::R_X86_64_PC32
:
2469 case elfcpp::R_X86_64_PC32_BND
:
2470 case elfcpp::R_X86_64_PC16
:
2471 case elfcpp::R_X86_64_PC8
:
2474 case elfcpp::R_X86_64_PLT32
:
2475 case elfcpp::R_X86_64_PLT32_BND
:
2476 // Since we know this is a local symbol, we can handle this as a
2480 case elfcpp::R_X86_64_GOTPC32
:
2481 case elfcpp::R_X86_64_GOTOFF64
:
2482 case elfcpp::R_X86_64_GOTPC64
:
2483 case elfcpp::R_X86_64_PLTOFF64
:
2484 // We need a GOT section.
2485 target
->got_section(symtab
, layout
);
2486 // For PLTOFF64, we'd normally want a PLT section, but since we
2487 // know this is a local symbol, no PLT is needed.
2490 case elfcpp::R_X86_64_GOT64
:
2491 case elfcpp::R_X86_64_GOT32
:
2492 case elfcpp::R_X86_64_GOTPCREL64
:
2493 case elfcpp::R_X86_64_GOTPCREL
:
2494 case elfcpp::R_X86_64_GOTPCRELX
:
2495 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2496 case elfcpp::R_X86_64_GOTPLT64
:
2498 // The symbol requires a GOT section.
2499 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
2501 // If the relocation symbol isn't IFUNC,
2502 // and is local, then we will convert
2503 // mov foo@GOTPCREL(%rip), %reg
2504 // to lea foo(%rip), %reg.
2505 // in Relocate::relocate.
2506 if ((r_type
== elfcpp::R_X86_64_GOTPCREL
2507 || r_type
== elfcpp::R_X86_64_GOTPCRELX
2508 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
2509 && reloc
.get_r_offset() >= 2
2512 section_size_type stype
;
2513 const unsigned char* view
= object
->section_contents(data_shndx
,
2515 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2520 // The symbol requires a GOT entry.
2521 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2523 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
2524 // lets function pointers compare correctly with shared
2525 // libraries. Otherwise we would need an IRELATIVE reloc.
2528 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
2530 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
2533 // If we are generating a shared object, we need to add a
2534 // dynamic relocation for this symbol's GOT entry.
2535 if (parameters
->options().output_is_position_independent())
2537 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2538 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2539 if (r_type
!= elfcpp::R_X86_64_GOT32
)
2541 unsigned int got_offset
=
2542 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
2543 rela_dyn
->add_local_relative(object
, r_sym
,
2544 elfcpp::R_X86_64_RELATIVE
,
2545 got
, got_offset
, 0, is_ifunc
);
2549 this->check_non_pic(object
, r_type
, NULL
);
2551 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2552 rela_dyn
->add_local(
2553 object
, r_sym
, r_type
, got
,
2554 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
2558 // For GOTPLT64, we'd normally want a PLT section, but since
2559 // we know this is a local symbol, no PLT is needed.
2563 case elfcpp::R_X86_64_COPY
:
2564 case elfcpp::R_X86_64_GLOB_DAT
:
2565 case elfcpp::R_X86_64_JUMP_SLOT
:
2566 case elfcpp::R_X86_64_RELATIVE
:
2567 case elfcpp::R_X86_64_IRELATIVE
:
2568 // These are outstanding tls relocs, which are unexpected when linking
2569 case elfcpp::R_X86_64_TPOFF64
:
2570 case elfcpp::R_X86_64_DTPMOD64
:
2571 case elfcpp::R_X86_64_TLSDESC
:
2572 gold_error(_("%s: unexpected reloc %u in object file"),
2573 object
->name().c_str(), r_type
);
2576 // These are initial tls relocs, which are expected when linking
2577 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2578 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2579 case elfcpp::R_X86_64_TLSDESC_CALL
:
2580 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2581 case elfcpp::R_X86_64_DTPOFF32
:
2582 case elfcpp::R_X86_64_DTPOFF64
:
2583 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2584 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2586 bool output_is_shared
= parameters
->options().shared();
2587 const tls::Tls_optimization optimized_type
2588 = Target_x86_64
<size
>::optimize_tls_reloc(!output_is_shared
,
2592 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
2593 if (optimized_type
== tls::TLSOPT_NONE
)
2595 // Create a pair of GOT entries for the module index and
2596 // dtv-relative offset.
2597 Output_data_got
<64, false>* got
2598 = target
->got_section(symtab
, layout
);
2599 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2600 unsigned int shndx
= lsym
.get_st_shndx();
2602 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
2604 object
->error(_("local symbol %u has bad shndx %u"),
2607 got
->add_local_pair_with_rel(object
, r_sym
,
2610 target
->rela_dyn_section(layout
),
2611 elfcpp::R_X86_64_DTPMOD64
);
2613 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2614 unsupported_reloc_local(object
, r_type
);
2617 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2618 target
->define_tls_base_symbol(symtab
, layout
);
2619 if (optimized_type
== tls::TLSOPT_NONE
)
2621 // Create reserved PLT and GOT entries for the resolver.
2622 target
->reserve_tlsdesc_entries(symtab
, layout
);
2624 // Generate a double GOT entry with an
2625 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
2626 // is resolved lazily, so the GOT entry needs to be in
2627 // an area in .got.plt, not .got. Call got_section to
2628 // make sure the section has been created.
2629 target
->got_section(symtab
, layout
);
2630 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
2631 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2632 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
2634 unsigned int got_offset
= got
->add_constant(0);
2635 got
->add_constant(0);
2636 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2638 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
2639 // We store the arguments we need in a vector, and
2640 // use the index into the vector as the parameter
2641 // to pass to the target specific routines.
2642 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
2643 void* arg
= reinterpret_cast<void*>(intarg
);
2644 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
2645 got
, got_offset
, 0);
2648 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2649 unsupported_reloc_local(object
, r_type
);
2652 case elfcpp::R_X86_64_TLSDESC_CALL
:
2655 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2656 if (optimized_type
== tls::TLSOPT_NONE
)
2658 // Create a GOT entry for the module index.
2659 target
->got_mod_index_entry(symtab
, layout
, object
);
2661 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2662 unsupported_reloc_local(object
, r_type
);
2665 case elfcpp::R_X86_64_DTPOFF32
:
2666 case elfcpp::R_X86_64_DTPOFF64
:
2669 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2670 layout
->set_has_static_tls();
2671 if (optimized_type
== tls::TLSOPT_NONE
)
2673 // Create a GOT entry for the tp-relative offset.
2674 Output_data_got
<64, false>* got
2675 = target
->got_section(symtab
, layout
);
2676 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2677 got
->add_local_with_rel(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
2678 target
->rela_dyn_section(layout
),
2679 elfcpp::R_X86_64_TPOFF64
);
2681 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2682 unsupported_reloc_local(object
, r_type
);
2685 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2686 layout
->set_has_static_tls();
2687 if (output_is_shared
)
2688 unsupported_reloc_local(object
, r_type
);
2697 case elfcpp::R_X86_64_SIZE32
:
2698 case elfcpp::R_X86_64_SIZE64
:
2700 gold_error(_("%s: unsupported reloc %u against local symbol"),
2701 object
->name().c_str(), r_type
);
2707 // Report an unsupported relocation against a global symbol.
2711 Target_x86_64
<size
>::Scan::unsupported_reloc_global(
2712 Sized_relobj_file
<size
, false>* object
,
2713 unsigned int r_type
,
2716 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2717 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2720 // Returns true if this relocation type could be that of a function pointer.
2723 Target_x86_64
<size
>::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2727 case elfcpp::R_X86_64_64
:
2728 case elfcpp::R_X86_64_32
:
2729 case elfcpp::R_X86_64_32S
:
2730 case elfcpp::R_X86_64_16
:
2731 case elfcpp::R_X86_64_8
:
2732 case elfcpp::R_X86_64_GOT64
:
2733 case elfcpp::R_X86_64_GOT32
:
2734 case elfcpp::R_X86_64_GOTPCREL64
:
2735 case elfcpp::R_X86_64_GOTPCREL
:
2736 case elfcpp::R_X86_64_GOTPCRELX
:
2737 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2738 case elfcpp::R_X86_64_GOTPLT64
:
2746 // For safe ICF, scan a relocation for a local symbol to check if it
2747 // corresponds to a function pointer being taken. In that case mark
2748 // the function whose pointer was taken as not foldable.
2752 Target_x86_64
<size
>::Scan::local_reloc_may_be_function_pointer(
2755 Target_x86_64
<size
>* ,
2756 Sized_relobj_file
<size
, false>* ,
2759 const elfcpp::Rela
<size
, false>& ,
2760 unsigned int r_type
,
2761 const elfcpp::Sym
<size
, false>&)
2763 // When building a shared library, do not fold any local symbols as it is
2764 // not possible to distinguish pointer taken versus a call by looking at
2765 // the relocation types.
2766 return (parameters
->options().shared()
2767 || possible_function_pointer_reloc(r_type
));
2770 // For safe ICF, scan a relocation for a global symbol to check if it
2771 // corresponds to a function pointer being taken. In that case mark
2772 // the function whose pointer was taken as not foldable.
2776 Target_x86_64
<size
>::Scan::global_reloc_may_be_function_pointer(
2779 Target_x86_64
<size
>* ,
2780 Sized_relobj_file
<size
, false>* ,
2783 const elfcpp::Rela
<size
, false>& ,
2784 unsigned int r_type
,
2787 // When building a shared library, do not fold symbols whose visibility
2788 // is hidden, internal or protected.
2789 return ((parameters
->options().shared()
2790 && (gsym
->visibility() == elfcpp::STV_INTERNAL
2791 || gsym
->visibility() == elfcpp::STV_PROTECTED
2792 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
2793 || possible_function_pointer_reloc(r_type
));
2796 // Scan a relocation for a global symbol.
2800 Target_x86_64
<size
>::Scan::global(Symbol_table
* symtab
,
2802 Target_x86_64
<size
>* target
,
2803 Sized_relobj_file
<size
, false>* object
,
2804 unsigned int data_shndx
,
2805 Output_section
* output_section
,
2806 const elfcpp::Rela
<size
, false>& reloc
,
2807 unsigned int r_type
,
2810 // A STT_GNU_IFUNC symbol may require a PLT entry.
2811 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2812 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2813 target
->make_plt_entry(symtab
, layout
, gsym
);
2817 case elfcpp::R_X86_64_NONE
:
2818 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2819 case elfcpp::R_X86_64_GNU_VTENTRY
:
2822 case elfcpp::R_X86_64_64
:
2823 case elfcpp::R_X86_64_32
:
2824 case elfcpp::R_X86_64_32S
:
2825 case elfcpp::R_X86_64_16
:
2826 case elfcpp::R_X86_64_8
:
2828 // Make a PLT entry if necessary.
2829 if (gsym
->needs_plt_entry())
2831 target
->make_plt_entry(symtab
, layout
, gsym
);
2832 // Since this is not a PC-relative relocation, we may be
2833 // taking the address of a function. In that case we need to
2834 // set the entry in the dynamic symbol table to the address of
2836 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2837 gsym
->set_needs_dynsym_value();
2839 // Make a dynamic relocation if necessary.
2840 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2842 if (!parameters
->options().output_is_position_independent()
2843 && gsym
->may_need_copy_reloc())
2845 target
->copy_reloc(symtab
, layout
, object
,
2846 data_shndx
, output_section
, gsym
, reloc
);
2848 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
2849 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
2850 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2851 && gsym
->can_use_relative_reloc(false)
2852 && !gsym
->is_from_dynobj()
2853 && !gsym
->is_undefined()
2854 && !gsym
->is_preemptible())
2856 // Use an IRELATIVE reloc for a locally defined
2857 // STT_GNU_IFUNC symbol. This makes a function
2858 // address in a PIE executable match the address in a
2859 // shared library that it links against.
2860 Reloc_section
* rela_dyn
=
2861 target
->rela_irelative_section(layout
);
2862 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
2863 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
2864 output_section
, object
,
2866 reloc
.get_r_offset(),
2867 reloc
.get_r_addend());
2869 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
2870 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
2871 && gsym
->can_use_relative_reloc(false))
2873 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2874 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
2875 output_section
, object
,
2877 reloc
.get_r_offset(),
2878 reloc
.get_r_addend(), false);
2882 this->check_non_pic(object
, r_type
, gsym
);
2883 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2884 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2885 data_shndx
, reloc
.get_r_offset(),
2886 reloc
.get_r_addend());
2892 case elfcpp::R_X86_64_PC64
:
2893 case elfcpp::R_X86_64_PC32
:
2894 case elfcpp::R_X86_64_PC32_BND
:
2895 case elfcpp::R_X86_64_PC16
:
2896 case elfcpp::R_X86_64_PC8
:
2898 // Make a PLT entry if necessary.
2899 if (gsym
->needs_plt_entry())
2900 target
->make_plt_entry(symtab
, layout
, gsym
);
2901 // Make a dynamic relocation if necessary.
2902 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2904 if (parameters
->options().output_is_executable()
2905 && gsym
->may_need_copy_reloc())
2907 target
->copy_reloc(symtab
, layout
, object
,
2908 data_shndx
, output_section
, gsym
, reloc
);
2912 this->check_non_pic(object
, r_type
, gsym
);
2913 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2914 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2915 data_shndx
, reloc
.get_r_offset(),
2916 reloc
.get_r_addend());
2922 case elfcpp::R_X86_64_GOT64
:
2923 case elfcpp::R_X86_64_GOT32
:
2924 case elfcpp::R_X86_64_GOTPCREL64
:
2925 case elfcpp::R_X86_64_GOTPCREL
:
2926 case elfcpp::R_X86_64_GOTPCRELX
:
2927 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2928 case elfcpp::R_X86_64_GOTPLT64
:
2930 // The symbol requires a GOT entry.
2931 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
2933 // If we convert this from
2934 // mov foo@GOTPCREL(%rip), %reg
2935 // to lea foo(%rip), %reg.
2936 // in Relocate::relocate, then there is nothing to do here.
2937 if ((r_type
== elfcpp::R_X86_64_GOTPCREL
2938 || r_type
== elfcpp::R_X86_64_GOTPCRELX
2939 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
2940 && reloc
.get_r_offset() >= 2
2941 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
))
2943 section_size_type stype
;
2944 const unsigned char* view
= object
->section_contents(data_shndx
,
2946 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2950 if (gsym
->final_value_is_known())
2952 // For a STT_GNU_IFUNC symbol we want the PLT address.
2953 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2954 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2956 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2960 // If this symbol is not fully resolved, we need to add a
2961 // dynamic relocation for it.
2962 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2964 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2966 // 1) The symbol may be defined in some other module.
2968 // 2) We are building a shared library and this is a
2969 // protected symbol; using GLOB_DAT means that the dynamic
2970 // linker can use the address of the PLT in the main
2971 // executable when appropriate so that function address
2972 // comparisons work.
2974 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2975 // code, again so that function address comparisons work.
2976 if (gsym
->is_from_dynobj()
2977 || gsym
->is_undefined()
2978 || gsym
->is_preemptible()
2979 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2980 && parameters
->options().shared())
2981 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2982 && parameters
->options().output_is_position_independent()))
2983 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
2984 elfcpp::R_X86_64_GLOB_DAT
);
2987 // For a STT_GNU_IFUNC symbol we want to write the PLT
2988 // offset into the GOT, so that function pointer
2989 // comparisons work correctly.
2991 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2992 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2995 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2996 // Tell the dynamic linker to use the PLT address
2997 // when resolving relocations.
2998 if (gsym
->is_from_dynobj()
2999 && !parameters
->options().shared())
3000 gsym
->set_needs_dynsym_value();
3004 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
3005 rela_dyn
->add_global_relative(gsym
,
3006 elfcpp::R_X86_64_RELATIVE
,
3007 got
, got_off
, 0, false);
3014 case elfcpp::R_X86_64_PLT32
:
3015 case elfcpp::R_X86_64_PLT32_BND
:
3016 // If the symbol is fully resolved, this is just a PC32 reloc.
3017 // Otherwise we need a PLT entry.
3018 if (gsym
->final_value_is_known())
3020 // If building a shared library, we can also skip the PLT entry
3021 // if the symbol is defined in the output file and is protected
3023 if (gsym
->is_defined()
3024 && !gsym
->is_from_dynobj()
3025 && !gsym
->is_preemptible())
3027 target
->make_plt_entry(symtab
, layout
, gsym
);
3030 case elfcpp::R_X86_64_GOTPC32
:
3031 case elfcpp::R_X86_64_GOTOFF64
:
3032 case elfcpp::R_X86_64_GOTPC64
:
3033 case elfcpp::R_X86_64_PLTOFF64
:
3034 // We need a GOT section.
3035 target
->got_section(symtab
, layout
);
3036 // For PLTOFF64, we also need a PLT entry (but only if the
3037 // symbol is not fully resolved).
3038 if (r_type
== elfcpp::R_X86_64_PLTOFF64
3039 && !gsym
->final_value_is_known())
3040 target
->make_plt_entry(symtab
, layout
, gsym
);
3043 case elfcpp::R_X86_64_COPY
:
3044 case elfcpp::R_X86_64_GLOB_DAT
:
3045 case elfcpp::R_X86_64_JUMP_SLOT
:
3046 case elfcpp::R_X86_64_RELATIVE
:
3047 case elfcpp::R_X86_64_IRELATIVE
:
3048 // These are outstanding tls relocs, which are unexpected when linking
3049 case elfcpp::R_X86_64_TPOFF64
:
3050 case elfcpp::R_X86_64_DTPMOD64
:
3051 case elfcpp::R_X86_64_TLSDESC
:
3052 gold_error(_("%s: unexpected reloc %u in object file"),
3053 object
->name().c_str(), r_type
);
3056 // These are initial tls relocs, which are expected for global()
3057 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3058 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3059 case elfcpp::R_X86_64_TLSDESC_CALL
:
3060 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3061 case elfcpp::R_X86_64_DTPOFF32
:
3062 case elfcpp::R_X86_64_DTPOFF64
:
3063 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3064 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3066 // For the Initial-Exec model, we can treat undef symbols as final
3067 // when building an executable.
3068 const bool is_final
= (gsym
->final_value_is_known() ||
3069 (r_type
== elfcpp::R_X86_64_GOTTPOFF
&&
3070 gsym
->is_undefined() &&
3071 parameters
->options().output_is_executable()));
3072 const tls::Tls_optimization optimized_type
3073 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
3076 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
3077 if (optimized_type
== tls::TLSOPT_NONE
)
3079 // Create a pair of GOT entries for the module index and
3080 // dtv-relative offset.
3081 Output_data_got
<64, false>* got
3082 = target
->got_section(symtab
, layout
);
3083 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
3084 target
->rela_dyn_section(layout
),
3085 elfcpp::R_X86_64_DTPMOD64
,
3086 elfcpp::R_X86_64_DTPOFF64
);
3088 else if (optimized_type
== tls::TLSOPT_TO_IE
)
3090 // Create a GOT entry for the tp-relative offset.
3091 Output_data_got
<64, false>* got
3092 = target
->got_section(symtab
, layout
);
3093 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3094 target
->rela_dyn_section(layout
),
3095 elfcpp::R_X86_64_TPOFF64
);
3097 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3098 unsupported_reloc_global(object
, r_type
, gsym
);
3101 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3102 target
->define_tls_base_symbol(symtab
, layout
);
3103 if (optimized_type
== tls::TLSOPT_NONE
)
3105 // Create reserved PLT and GOT entries for the resolver.
3106 target
->reserve_tlsdesc_entries(symtab
, layout
);
3108 // Create a double GOT entry with an R_X86_64_TLSDESC
3109 // reloc. The R_X86_64_TLSDESC reloc is resolved
3110 // lazily, so the GOT entry needs to be in an area in
3111 // .got.plt, not .got. Call got_section to make sure
3112 // the section has been created.
3113 target
->got_section(symtab
, layout
);
3114 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
3115 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
3116 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
3117 elfcpp::R_X86_64_TLSDESC
, 0);
3119 else if (optimized_type
== tls::TLSOPT_TO_IE
)
3121 // Create a GOT entry for the tp-relative offset.
3122 Output_data_got
<64, false>* got
3123 = target
->got_section(symtab
, layout
);
3124 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3125 target
->rela_dyn_section(layout
),
3126 elfcpp::R_X86_64_TPOFF64
);
3128 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3129 unsupported_reloc_global(object
, r_type
, gsym
);
3132 case elfcpp::R_X86_64_TLSDESC_CALL
:
3135 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3136 if (optimized_type
== tls::TLSOPT_NONE
)
3138 // Create a GOT entry for the module index.
3139 target
->got_mod_index_entry(symtab
, layout
, object
);
3141 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3142 unsupported_reloc_global(object
, r_type
, gsym
);
3145 case elfcpp::R_X86_64_DTPOFF32
:
3146 case elfcpp::R_X86_64_DTPOFF64
:
3149 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3150 layout
->set_has_static_tls();
3151 if (optimized_type
== tls::TLSOPT_NONE
)
3153 // Create a GOT entry for the tp-relative offset.
3154 Output_data_got
<64, false>* got
3155 = target
->got_section(symtab
, layout
);
3156 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3157 target
->rela_dyn_section(layout
),
3158 elfcpp::R_X86_64_TPOFF64
);
3160 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3161 unsupported_reloc_global(object
, r_type
, gsym
);
3164 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3165 layout
->set_has_static_tls();
3166 if (parameters
->options().shared())
3167 unsupported_reloc_global(object
, r_type
, gsym
);
3176 case elfcpp::R_X86_64_SIZE32
:
3177 case elfcpp::R_X86_64_SIZE64
:
3179 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3180 object
->name().c_str(), r_type
,
3181 gsym
->demangled_name().c_str());
3188 Target_x86_64
<size
>::gc_process_relocs(Symbol_table
* symtab
,
3190 Sized_relobj_file
<size
, false>* object
,
3191 unsigned int data_shndx
,
3192 unsigned int sh_type
,
3193 const unsigned char* prelocs
,
3195 Output_section
* output_section
,
3196 bool needs_special_offset_handling
,
3197 size_t local_symbol_count
,
3198 const unsigned char* plocal_symbols
)
3200 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
3203 if (sh_type
== elfcpp::SHT_REL
)
3208 gold::gc_process_relocs
<size
, false, Target_x86_64
<size
>, Scan
,
3218 needs_special_offset_handling
,
3223 // Scan relocations for a section.
3227 Target_x86_64
<size
>::scan_relocs(Symbol_table
* symtab
,
3229 Sized_relobj_file
<size
, false>* object
,
3230 unsigned int data_shndx
,
3231 unsigned int sh_type
,
3232 const unsigned char* prelocs
,
3234 Output_section
* output_section
,
3235 bool needs_special_offset_handling
,
3236 size_t local_symbol_count
,
3237 const unsigned char* plocal_symbols
)
3239 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
3242 if (sh_type
== elfcpp::SHT_REL
)
3244 gold_error(_("%s: unsupported REL reloc section"),
3245 object
->name().c_str());
3249 gold::scan_relocs
<size
, false, Target_x86_64
<size
>, Scan
, Classify_reloc
>(
3258 needs_special_offset_handling
,
3263 // Finalize the sections.
3267 Target_x86_64
<size
>::do_finalize_sections(
3269 const Input_objects
*,
3270 Symbol_table
* symtab
)
3272 const Reloc_section
* rel_plt
= (this->plt_
== NULL
3274 : this->plt_
->rela_plt());
3275 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
3276 this->rela_dyn_
, true, false);
3278 // Fill in some more dynamic tags.
3279 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
3282 if (this->plt_
!= NULL
3283 && this->plt_
->output_section() != NULL
3284 && this->plt_
->has_tlsdesc_entry())
3286 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
3287 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
3288 this->got_
->finalize_data_size();
3289 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
3290 this->plt_
, plt_offset
);
3291 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
3292 this->got_
, got_offset
);
3296 // Emit any relocs we saved in an attempt to avoid generating COPY
3298 if (this->copy_relocs_
.any_saved_relocs())
3299 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
3301 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3302 // the .got.plt section.
3303 Symbol
* sym
= this->global_offset_table_
;
3306 uint64_t data_size
= this->got_plt_
->current_data_size();
3307 symtab
->get_sized_symbol
<size
>(sym
)->set_symsize(data_size
);
3310 if (parameters
->doing_static_link()
3311 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
3313 // If linking statically, make sure that the __rela_iplt symbols
3314 // were defined if necessary, even if we didn't create a PLT.
3315 static const Define_symbol_in_segment syms
[] =
3318 "__rela_iplt_start", // name
3319 elfcpp::PT_LOAD
, // segment_type
3320 elfcpp::PF_W
, // segment_flags_set
3321 elfcpp::PF(0), // segment_flags_clear
3324 elfcpp::STT_NOTYPE
, // type
3325 elfcpp::STB_GLOBAL
, // binding
3326 elfcpp::STV_HIDDEN
, // visibility
3328 Symbol::SEGMENT_START
, // offset_from_base
3332 "__rela_iplt_end", // name
3333 elfcpp::PT_LOAD
, // segment_type
3334 elfcpp::PF_W
, // segment_flags_set
3335 elfcpp::PF(0), // segment_flags_clear
3338 elfcpp::STT_NOTYPE
, // type
3339 elfcpp::STB_GLOBAL
, // binding
3340 elfcpp::STV_HIDDEN
, // visibility
3342 Symbol::SEGMENT_START
, // offset_from_base
3347 symtab
->define_symbols(layout
, 2, syms
,
3348 layout
->script_options()->saw_sections_clause());
3352 // Perform a relocation.
3356 Target_x86_64
<size
>::Relocate::relocate(
3357 const Relocate_info
<size
, false>* relinfo
,
3359 Target_x86_64
<size
>* target
,
3362 const unsigned char* preloc
,
3363 const Sized_symbol
<size
>* gsym
,
3364 const Symbol_value
<size
>* psymval
,
3365 unsigned char* view
,
3366 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
3367 section_size_type view_size
)
3369 const elfcpp::Rela
<size
, false> rela(preloc
);
3370 unsigned int r_type
= elfcpp::elf_r_type
<size
>(rela
.get_r_info());
3372 if (this->skip_call_tls_get_addr_
)
3374 if ((r_type
!= elfcpp::R_X86_64_PLT32
3375 && r_type
!= elfcpp::R_X86_64_PLT32_BND
3376 && r_type
!= elfcpp::R_X86_64_PC32_BND
3377 && r_type
!= elfcpp::R_X86_64_PC32
)
3379 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
3381 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3382 _("missing expected TLS relocation"));
3386 this->skip_call_tls_get_addr_
= false;
3394 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
3396 // Pick the value to use for symbols defined in the PLT.
3397 Symbol_value
<size
> symval
;
3399 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
3401 symval
.set_output_value(target
->plt_address_for_global(gsym
));
3404 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
3406 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3407 if (object
->local_has_plt_offset(r_sym
))
3409 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
3414 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3416 // Get the GOT offset if needed.
3417 // The GOT pointer points to the end of the GOT section.
3418 // We need to subtract the size of the GOT section to get
3419 // the actual offset to use in the relocation.
3420 bool have_got_offset
= false;
3421 // Since the actual offset is always negative, we use signed int to
3422 // support 64-bit GOT relocations.
3426 case elfcpp::R_X86_64_GOT32
:
3427 case elfcpp::R_X86_64_GOT64
:
3428 case elfcpp::R_X86_64_GOTPLT64
:
3429 case elfcpp::R_X86_64_GOTPCREL64
:
3432 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
3433 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
3437 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3438 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
3439 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
3440 - target
->got_size());
3442 have_got_offset
= true;
3451 case elfcpp::R_X86_64_NONE
:
3452 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3453 case elfcpp::R_X86_64_GNU_VTENTRY
:
3456 case elfcpp::R_X86_64_64
:
3457 Relocate_functions
<size
, false>::rela64(view
, object
, psymval
, addend
);
3460 case elfcpp::R_X86_64_PC64
:
3461 Relocate_functions
<size
, false>::pcrela64(view
, object
, psymval
, addend
,
3465 case elfcpp::R_X86_64_32
:
3466 // FIXME: we need to verify that value + addend fits into 32 bits:
3467 // uint64_t x = value + addend;
3468 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
3469 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
3470 Relocate_functions
<size
, false>::rela32(view
, object
, psymval
, addend
);
3473 case elfcpp::R_X86_64_32S
:
3474 // FIXME: we need to verify that value + addend fits into 32 bits:
3475 // int64_t x = value + addend; // note this quantity is signed!
3476 // x == static_cast<int64_t>(static_cast<int32_t>(x))
3477 Relocate_functions
<size
, false>::rela32(view
, object
, psymval
, addend
);
3480 case elfcpp::R_X86_64_PC32
:
3481 case elfcpp::R_X86_64_PC32_BND
:
3482 Relocate_functions
<size
, false>::pcrela32(view
, object
, psymval
, addend
,
3486 case elfcpp::R_X86_64_16
:
3487 Relocate_functions
<size
, false>::rela16(view
, object
, psymval
, addend
);
3490 case elfcpp::R_X86_64_PC16
:
3491 Relocate_functions
<size
, false>::pcrela16(view
, object
, psymval
, addend
,
3495 case elfcpp::R_X86_64_8
:
3496 Relocate_functions
<size
, false>::rela8(view
, object
, psymval
, addend
);
3499 case elfcpp::R_X86_64_PC8
:
3500 Relocate_functions
<size
, false>::pcrela8(view
, object
, psymval
, addend
,
3504 case elfcpp::R_X86_64_PLT32
:
3505 case elfcpp::R_X86_64_PLT32_BND
:
3506 gold_assert(gsym
== NULL
3507 || gsym
->has_plt_offset()
3508 || gsym
->final_value_is_known()
3509 || (gsym
->is_defined()
3510 && !gsym
->is_from_dynobj()
3511 && !gsym
->is_preemptible()));
3512 // Note: while this code looks the same as for R_X86_64_PC32, it
3513 // behaves differently because psymval was set to point to
3514 // the PLT entry, rather than the symbol, in Scan::global().
3515 Relocate_functions
<size
, false>::pcrela32(view
, object
, psymval
, addend
,
3519 case elfcpp::R_X86_64_PLTOFF64
:
3522 gold_assert(gsym
->has_plt_offset()
3523 || gsym
->final_value_is_known());
3524 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
;
3525 // This is the address of GLOBAL_OFFSET_TABLE.
3526 got_address
= target
->got_plt_section()->address();
3527 Relocate_functions
<size
, false>::rela64(view
, object
, psymval
,
3528 addend
- got_address
);
3532 case elfcpp::R_X86_64_GOT32
:
3533 gold_assert(have_got_offset
);
3534 Relocate_functions
<size
, false>::rela32(view
, got_offset
, addend
);
3537 case elfcpp::R_X86_64_GOTPC32
:
3540 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3541 value
= target
->got_plt_section()->address();
3542 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
3546 case elfcpp::R_X86_64_GOT64
:
3547 case elfcpp::R_X86_64_GOTPLT64
:
3548 // R_X86_64_GOTPLT64 is obsolete and treated the the same as
3550 gold_assert(have_got_offset
);
3551 Relocate_functions
<size
, false>::rela64(view
, got_offset
, addend
);
3554 case elfcpp::R_X86_64_GOTPC64
:
3557 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3558 value
= target
->got_plt_section()->address();
3559 Relocate_functions
<size
, false>::pcrela64(view
, value
, addend
, address
);
3563 case elfcpp::R_X86_64_GOTOFF64
:
3565 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3566 value
= (psymval
->value(object
, 0)
3567 - target
->got_plt_section()->address());
3568 Relocate_functions
<size
, false>::rela64(view
, value
, addend
);
3572 case elfcpp::R_X86_64_GOTPCREL
:
3573 case elfcpp::R_X86_64_GOTPCRELX
:
3574 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3577 // mov foo@GOTPCREL(%rip), %reg
3578 // to lea foo(%rip), %reg.
3580 if (rela
.get_r_offset() >= 2
3582 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
3584 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
))))
3587 Relocate_functions
<size
, false>::pcrela32(view
, object
, psymval
, addend
,
3594 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
3595 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
3599 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3600 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
3601 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
3602 - target
->got_size());
3604 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3605 value
= target
->got_plt_section()->address() + got_offset
;
3606 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
3611 case elfcpp::R_X86_64_GOTPCREL64
:
3613 gold_assert(have_got_offset
);
3614 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3615 value
= target
->got_plt_section()->address() + got_offset
;
3616 Relocate_functions
<size
, false>::pcrela64(view
, value
, addend
, address
);
3620 case elfcpp::R_X86_64_COPY
:
3621 case elfcpp::R_X86_64_GLOB_DAT
:
3622 case elfcpp::R_X86_64_JUMP_SLOT
:
3623 case elfcpp::R_X86_64_RELATIVE
:
3624 case elfcpp::R_X86_64_IRELATIVE
:
3625 // These are outstanding tls relocs, which are unexpected when linking
3626 case elfcpp::R_X86_64_TPOFF64
:
3627 case elfcpp::R_X86_64_DTPMOD64
:
3628 case elfcpp::R_X86_64_TLSDESC
:
3629 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3630 _("unexpected reloc %u in object file"),
3634 // These are initial tls relocs, which are expected when linking
3635 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3636 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3637 case elfcpp::R_X86_64_TLSDESC_CALL
:
3638 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3639 case elfcpp::R_X86_64_DTPOFF32
:
3640 case elfcpp::R_X86_64_DTPOFF64
:
3641 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3642 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3643 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
3644 view
, address
, view_size
);
3647 case elfcpp::R_X86_64_SIZE32
:
3648 case elfcpp::R_X86_64_SIZE64
:
3650 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3651 _("unsupported reloc %u"),
3659 // Perform a TLS relocation.
3663 Target_x86_64
<size
>::Relocate::relocate_tls(
3664 const Relocate_info
<size
, false>* relinfo
,
3665 Target_x86_64
<size
>* target
,
3667 const elfcpp::Rela
<size
, false>& rela
,
3668 unsigned int r_type
,
3669 const Sized_symbol
<size
>* gsym
,
3670 const Symbol_value
<size
>* psymval
,
3671 unsigned char* view
,
3672 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
3673 section_size_type view_size
)
3675 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3677 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
3678 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3679 elfcpp::Shdr
<size
, false> data_shdr(relinfo
->data_shdr
);
3680 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
3682 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
3684 const bool is_final
= (gsym
== NULL
3685 ? !parameters
->options().shared()
3686 : gsym
->final_value_is_known());
3687 tls::Tls_optimization optimized_type
3688 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
3691 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3692 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3694 // If this code sequence is used in a non-executable section,
3695 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3696 // on the assumption that it's being used by itself in a debug
3697 // section. Therefore, in the unlikely event that the code
3698 // sequence appears in a non-executable section, we simply
3699 // leave it unoptimized.
3700 optimized_type
= tls::TLSOPT_NONE
;
3702 if (optimized_type
== tls::TLSOPT_TO_LE
)
3704 if (tls_segment
== NULL
)
3706 gold_assert(parameters
->errors()->error_count() > 0
3707 || issue_undefined_symbol_error(gsym
));
3710 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3711 rela
, r_type
, value
, view
,
3717 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3718 ? GOT_TYPE_TLS_OFFSET
3719 : GOT_TYPE_TLS_PAIR
);
3720 unsigned int got_offset
;
3723 gold_assert(gsym
->has_got_offset(got_type
));
3724 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3728 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3729 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3730 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3731 - target
->got_size());
3733 if (optimized_type
== tls::TLSOPT_TO_IE
)
3735 value
= target
->got_plt_section()->address() + got_offset
;
3736 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
3737 value
, view
, address
, view_size
);
3740 else if (optimized_type
== tls::TLSOPT_NONE
)
3742 // Relocate the field with the offset of the pair of GOT
3744 value
= target
->got_plt_section()->address() + got_offset
;
3745 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
3750 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3751 _("unsupported reloc %u"), r_type
);
3754 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3755 case elfcpp::R_X86_64_TLSDESC_CALL
:
3756 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3758 // See above comment for R_X86_64_TLSGD.
3759 optimized_type
= tls::TLSOPT_NONE
;
3761 if (optimized_type
== tls::TLSOPT_TO_LE
)
3763 if (tls_segment
== NULL
)
3765 gold_assert(parameters
->errors()->error_count() > 0
3766 || issue_undefined_symbol_error(gsym
));
3769 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3770 rela
, r_type
, value
, view
,
3776 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3777 ? GOT_TYPE_TLS_OFFSET
3778 : GOT_TYPE_TLS_DESC
);
3779 unsigned int got_offset
= 0;
3780 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
3781 && optimized_type
== tls::TLSOPT_NONE
)
3783 // We created GOT entries in the .got.tlsdesc portion of
3784 // the .got.plt section, but the offset stored in the
3785 // symbol is the offset within .got.tlsdesc.
3786 got_offset
= (target
->got_size()
3787 + target
->got_plt_section()->data_size());
3791 gold_assert(gsym
->has_got_offset(got_type
));
3792 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3796 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3797 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3798 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3799 - target
->got_size());
3801 if (optimized_type
== tls::TLSOPT_TO_IE
)
3803 if (tls_segment
== NULL
)
3805 gold_assert(parameters
->errors()->error_count() > 0
3806 || issue_undefined_symbol_error(gsym
));
3809 value
= target
->got_plt_section()->address() + got_offset
;
3810 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
,
3811 rela
, r_type
, value
, view
, address
,
3815 else if (optimized_type
== tls::TLSOPT_NONE
)
3817 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
3819 // Relocate the field with the offset of the pair of GOT
3821 value
= target
->got_plt_section()->address() + got_offset
;
3822 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
3828 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3829 _("unsupported reloc %u"), r_type
);
3832 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3833 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3835 // See above comment for R_X86_64_TLSGD.
3836 optimized_type
= tls::TLSOPT_NONE
;
3838 if (optimized_type
== tls::TLSOPT_TO_LE
)
3840 if (tls_segment
== NULL
)
3842 gold_assert(parameters
->errors()->error_count() > 0
3843 || issue_undefined_symbol_error(gsym
));
3846 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
3847 value
, view
, view_size
);
3850 else if (optimized_type
== tls::TLSOPT_NONE
)
3852 // Relocate the field with the offset of the GOT entry for
3853 // the module index.
3854 unsigned int got_offset
;
3855 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3856 - target
->got_size());
3857 value
= target
->got_plt_section()->address() + got_offset
;
3858 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
3862 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3863 _("unsupported reloc %u"), r_type
);
3866 case elfcpp::R_X86_64_DTPOFF32
:
3867 // This relocation type is used in debugging information.
3868 // In that case we need to not optimize the value. If the
3869 // section is not executable, then we assume we should not
3870 // optimize this reloc. See comments above for R_X86_64_TLSGD,
3871 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3873 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
3875 if (tls_segment
== NULL
)
3877 gold_assert(parameters
->errors()->error_count() > 0
3878 || issue_undefined_symbol_error(gsym
));
3881 value
-= tls_segment
->memsz();
3883 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
3886 case elfcpp::R_X86_64_DTPOFF64
:
3887 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3888 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
3890 if (tls_segment
== NULL
)
3892 gold_assert(parameters
->errors()->error_count() > 0
3893 || issue_undefined_symbol_error(gsym
));
3896 value
-= tls_segment
->memsz();
3898 Relocate_functions
<size
, false>::rela64(view
, value
, addend
);
3901 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3903 && gsym
->is_undefined()
3904 && parameters
->options().output_is_executable())
3906 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
3908 r_type
, value
, view
,
3912 else if (optimized_type
== tls::TLSOPT_TO_LE
)
3914 if (tls_segment
== NULL
)
3916 gold_assert(parameters
->errors()->error_count() > 0
3917 || issue_undefined_symbol_error(gsym
));
3920 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
3922 r_type
, value
, view
,
3926 else if (optimized_type
== tls::TLSOPT_NONE
)
3928 // Relocate the field with the offset of the GOT entry for
3929 // the tp-relative offset of the symbol.
3930 unsigned int got_offset
;
3933 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
3934 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
3935 - target
->got_size());
3939 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3940 gold_assert(object
->local_has_got_offset(r_sym
,
3941 GOT_TYPE_TLS_OFFSET
));
3942 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
3943 - target
->got_size());
3945 value
= target
->got_plt_section()->address() + got_offset
;
3946 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
3950 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3951 _("unsupported reloc type %u"),
3955 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3956 if (tls_segment
== NULL
)
3958 gold_assert(parameters
->errors()->error_count() > 0
3959 || issue_undefined_symbol_error(gsym
));
3962 value
-= tls_segment
->memsz();
3963 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
3968 // Do a relocation in which we convert a TLS General-Dynamic to an
3973 Target_x86_64
<size
>::Relocate::tls_gd_to_ie(
3974 const Relocate_info
<size
, false>* relinfo
,
3977 const elfcpp::Rela
<size
, false>& rela
,
3979 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
3980 unsigned char* view
,
3981 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
3982 section_size_type view_size
)
3985 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3986 // .word 0x6666; rex64; call __tls_get_addr
3987 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3989 // leaq foo@tlsgd(%rip),%rdi;
3990 // .word 0x6666; rex64; call __tls_get_addr
3991 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
3993 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
3994 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3995 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
3999 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4001 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4002 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
4003 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4008 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4010 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4011 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
4012 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4016 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4017 Relocate_functions
<size
, false>::pcrela32(view
+ 8, value
, addend
- 8,
4020 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4022 this->skip_call_tls_get_addr_
= true;
4025 // Do a relocation in which we convert a TLS General-Dynamic to a
4030 Target_x86_64
<size
>::Relocate::tls_gd_to_le(
4031 const Relocate_info
<size
, false>* relinfo
,
4033 Output_segment
* tls_segment
,
4034 const elfcpp::Rela
<size
, false>& rela
,
4036 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4037 unsigned char* view
,
4038 section_size_type view_size
)
4041 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4042 // .word 0x6666; rex64; call __tls_get_addr
4043 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4045 // leaq foo@tlsgd(%rip),%rdi;
4046 // .word 0x6666; rex64; call __tls_get_addr
4047 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4049 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
4050 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4051 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
4055 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4057 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4058 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
4059 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4064 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4066 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4067 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
4069 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4073 value
-= tls_segment
->memsz();
4074 Relocate_functions
<size
, false>::rela32(view
+ 8, value
, 0);
4076 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4078 this->skip_call_tls_get_addr_
= true;
4081 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4085 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_ie(
4086 const Relocate_info
<size
, false>* relinfo
,
4089 const elfcpp::Rela
<size
, false>& rela
,
4090 unsigned int r_type
,
4091 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4092 unsigned char* view
,
4093 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4094 section_size_type view_size
)
4096 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4098 // leaq foo@tlsdesc(%rip), %rax
4099 // ==> movq foo@gottpoff(%rip), %rax
4100 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4101 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4102 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4103 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
4105 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4106 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
4110 // call *foo@tlscall(%rax)
4112 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
4113 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
4114 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4115 view
[0] == 0xff && view
[1] == 0x10);
4121 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4125 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_le(
4126 const Relocate_info
<size
, false>* relinfo
,
4128 Output_segment
* tls_segment
,
4129 const elfcpp::Rela
<size
, false>& rela
,
4130 unsigned int r_type
,
4131 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4132 unsigned char* view
,
4133 section_size_type view_size
)
4135 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4137 // leaq foo@tlsdesc(%rip), %rax
4138 // ==> movq foo@tpoff, %rax
4139 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4140 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4141 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4142 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
4145 value
-= tls_segment
->memsz();
4146 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
4150 // call *foo@tlscall(%rax)
4152 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
4153 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
4154 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4155 view
[0] == 0xff && view
[1] == 0x10);
4163 Target_x86_64
<size
>::Relocate::tls_ld_to_le(
4164 const Relocate_info
<size
, false>* relinfo
,
4167 const elfcpp::Rela
<size
, false>& rela
,
4169 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
4170 unsigned char* view
,
4171 section_size_type view_size
)
4173 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4175 // ... leq foo@dtpoff(%rax),%reg
4176 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4178 // ... leq foo@dtpoff(%rax),%reg
4179 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4181 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4182 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
4184 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4185 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
4187 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
4190 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4192 memcpy(view
- 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4194 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4196 this->skip_call_tls_get_addr_
= true;
4199 // Do a relocation in which we convert a TLS Initial-Exec to a
4204 Target_x86_64
<size
>::Relocate::tls_ie_to_le(
4205 const Relocate_info
<size
, false>* relinfo
,
4207 Output_segment
* tls_segment
,
4208 const elfcpp::Rela
<size
, false>& rela
,
4210 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4211 unsigned char* view
,
4212 section_size_type view_size
)
4214 // We need to examine the opcodes to figure out which instruction we
4217 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4218 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4220 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4221 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4223 unsigned char op1
= view
[-3];
4224 unsigned char op2
= view
[-2];
4225 unsigned char op3
= view
[-1];
4226 unsigned char reg
= op3
>> 3;
4233 else if (size
== 32 && op1
== 0x44)
4236 view
[-1] = 0xc0 | reg
;
4240 // Special handling for %rsp.
4243 else if (size
== 32 && op1
== 0x44)
4246 view
[-1] = 0xc0 | reg
;
4253 else if (size
== 32 && op1
== 0x44)
4256 view
[-1] = 0x80 | reg
| (reg
<< 3);
4259 if (tls_segment
!= NULL
)
4260 value
-= tls_segment
->memsz();
4261 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
4264 // Relocate section data.
4268 Target_x86_64
<size
>::relocate_section(
4269 const Relocate_info
<size
, false>* relinfo
,
4270 unsigned int sh_type
,
4271 const unsigned char* prelocs
,
4273 Output_section
* output_section
,
4274 bool needs_special_offset_handling
,
4275 unsigned char* view
,
4276 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4277 section_size_type view_size
,
4278 const Reloc_symbol_changes
* reloc_symbol_changes
)
4280 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4283 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4285 gold::relocate_section
<size
, false, Target_x86_64
<size
>, Relocate
,
4286 gold::Default_comdat_behavior
, Classify_reloc
>(
4292 needs_special_offset_handling
,
4296 reloc_symbol_changes
);
4299 // Apply an incremental relocation. Incremental relocations always refer
4300 // to global symbols.
4304 Target_x86_64
<size
>::apply_relocation(
4305 const Relocate_info
<size
, false>* relinfo
,
4306 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
4307 unsigned int r_type
,
4308 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
4310 unsigned char* view
,
4311 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4312 section_size_type view_size
)
4314 gold::apply_relocation
<size
, false, Target_x86_64
<size
>,
4315 typename Target_x86_64
<size
>::Relocate
>(
4327 // Scan the relocs during a relocatable link.
4331 Target_x86_64
<size
>::scan_relocatable_relocs(
4332 Symbol_table
* symtab
,
4334 Sized_relobj_file
<size
, false>* object
,
4335 unsigned int data_shndx
,
4336 unsigned int sh_type
,
4337 const unsigned char* prelocs
,
4339 Output_section
* output_section
,
4340 bool needs_special_offset_handling
,
4341 size_t local_symbol_count
,
4342 const unsigned char* plocal_symbols
,
4343 Relocatable_relocs
* rr
)
4345 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4347 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
4348 Scan_relocatable_relocs
;
4350 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4352 gold::scan_relocatable_relocs
<size
, false, Scan_relocatable_relocs
>(
4360 needs_special_offset_handling
,
4366 // Scan the relocs for --emit-relocs.
4370 Target_x86_64
<size
>::emit_relocs_scan(
4371 Symbol_table
* symtab
,
4373 Sized_relobj_file
<size
, false>* object
,
4374 unsigned int data_shndx
,
4375 unsigned int sh_type
,
4376 const unsigned char* prelocs
,
4378 Output_section
* output_section
,
4379 bool needs_special_offset_handling
,
4380 size_t local_symbol_count
,
4381 const unsigned char* plocal_syms
,
4382 Relocatable_relocs
* rr
)
4384 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4386 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
4387 Emit_relocs_strategy
;
4389 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4391 gold::scan_relocatable_relocs
<size
, false, Emit_relocs_strategy
>(
4399 needs_special_offset_handling
,
4405 // Relocate a section during a relocatable link.
4409 Target_x86_64
<size
>::relocate_relocs(
4410 const Relocate_info
<size
, false>* relinfo
,
4411 unsigned int sh_type
,
4412 const unsigned char* prelocs
,
4414 Output_section
* output_section
,
4415 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
4416 unsigned char* view
,
4417 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
4418 section_size_type view_size
,
4419 unsigned char* reloc_view
,
4420 section_size_type reloc_view_size
)
4422 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4425 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4427 gold::relocate_relocs
<size
, false, Classify_reloc
>(
4432 offset_in_output_section
,
4440 // Return the value to use for a dynamic which requires special
4441 // treatment. This is how we support equality comparisons of function
4442 // pointers across shared library boundaries, as described in the
4443 // processor specific ABI supplement.
4447 Target_x86_64
<size
>::do_dynsym_value(const Symbol
* gsym
) const
4449 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
4450 return this->plt_address_for_global(gsym
);
4453 // Return a string used to fill a code section with nops to take up
4454 // the specified length.
4458 Target_x86_64
<size
>::do_code_fill(section_size_type length
) const
4462 // Build a jmpq instruction to skip over the bytes.
4463 unsigned char jmp
[5];
4465 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
4466 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
4467 + std::string(length
- 5, static_cast<char>(0x90)));
4470 // Nop sequences of various lengths.
4471 const char nop1
[1] = { '\x90' }; // nop
4472 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
4473 const char nop3
[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4474 const char nop4
[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
4476 const char nop5
[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
4478 const char nop6
[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
4479 '\x44', '\x00', '\x00' };
4480 const char nop7
[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
4481 '\x00', '\x00', '\x00',
4483 const char nop8
[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
4484 '\x00', '\x00', '\x00',
4486 const char nop9
[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
4487 '\x84', '\x00', '\x00',
4488 '\x00', '\x00', '\x00' };
4489 const char nop10
[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4490 '\x1f', '\x84', '\x00',
4491 '\x00', '\x00', '\x00',
4493 const char nop11
[11] = { '\x66', '\x66', '\x2e', // data16
4494 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4495 '\x00', '\x00', '\x00',
4497 const char nop12
[12] = { '\x66', '\x66', '\x66', // data16; data16
4498 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4499 '\x84', '\x00', '\x00',
4500 '\x00', '\x00', '\x00' };
4501 const char nop13
[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4502 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4503 '\x1f', '\x84', '\x00',
4504 '\x00', '\x00', '\x00',
4506 const char nop14
[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4507 '\x66', '\x66', '\x2e', // data16
4508 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4509 '\x00', '\x00', '\x00',
4511 const char nop15
[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4512 '\x66', '\x66', '\x66', // data16; data16
4513 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4514 '\x84', '\x00', '\x00',
4515 '\x00', '\x00', '\x00' };
4517 const char* nops
[16] = {
4519 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
4520 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
4523 return std::string(nops
[length
], length
);
4526 // Return the addend to use for a target specific relocation. The
4527 // only target specific relocation is R_X86_64_TLSDESC for a local
4528 // symbol. We want to set the addend is the offset of the local
4529 // symbol in the TLS segment.
4533 Target_x86_64
<size
>::do_reloc_addend(void* arg
, unsigned int r_type
,
4536 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
4537 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
4538 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
4539 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
4540 const Symbol_value
<size
>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
4541 gold_assert(psymval
->is_tls_symbol());
4542 // The value of a TLS symbol is the offset in the TLS segment.
4543 return psymval
->value(ti
.object
, 0);
4546 // Return the value to use for the base of a DW_EH_PE_datarel offset
4547 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
4548 // assembler can not write out the difference between two labels in
4549 // different sections, so instead of using a pc-relative value they
4550 // use an offset from the GOT.
4554 Target_x86_64
<size
>::do_ehframe_datarel_base() const
4556 gold_assert(this->global_offset_table_
!= NULL
);
4557 Symbol
* sym
= this->global_offset_table_
;
4558 Sized_symbol
<size
>* ssym
= static_cast<Sized_symbol
<size
>*>(sym
);
4559 return ssym
->value();
4562 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4563 // compiled with -fsplit-stack. The function calls non-split-stack
4564 // code. We have to change the function so that it always ensures
4565 // that it has enough stack space to run some random function.
4567 static const unsigned char cmp_insn_32
[] = { 0x64, 0x3b, 0x24, 0x25 };
4568 static const unsigned char lea_r10_insn_32
[] = { 0x44, 0x8d, 0x94, 0x24 };
4569 static const unsigned char lea_r11_insn_32
[] = { 0x44, 0x8d, 0x9c, 0x24 };
4571 static const unsigned char cmp_insn_64
[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
4572 static const unsigned char lea_r10_insn_64
[] = { 0x4c, 0x8d, 0x94, 0x24 };
4573 static const unsigned char lea_r11_insn_64
[] = { 0x4c, 0x8d, 0x9c, 0x24 };
4577 Target_x86_64
<size
>::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
4578 section_offset_type fnoffset
,
4579 section_size_type fnsize
,
4580 const unsigned char*,
4582 unsigned char* view
,
4583 section_size_type view_size
,
4585 std::string
* to
) const
4587 const char* const cmp_insn
= reinterpret_cast<const char*>
4588 (size
== 32 ? cmp_insn_32
: cmp_insn_64
);
4589 const char* const lea_r10_insn
= reinterpret_cast<const char*>
4590 (size
== 32 ? lea_r10_insn_32
: lea_r10_insn_64
);
4591 const char* const lea_r11_insn
= reinterpret_cast<const char*>
4592 (size
== 32 ? lea_r11_insn_32
: lea_r11_insn_64
);
4594 const size_t cmp_insn_len
=
4595 (size
== 32 ? sizeof(cmp_insn_32
) : sizeof(cmp_insn_64
));
4596 const size_t lea_r10_insn_len
=
4597 (size
== 32 ? sizeof(lea_r10_insn_32
) : sizeof(lea_r10_insn_64
));
4598 const size_t lea_r11_insn_len
=
4599 (size
== 32 ? sizeof(lea_r11_insn_32
) : sizeof(lea_r11_insn_64
));
4600 const size_t nop_len
= (size
== 32 ? 7 : 8);
4602 // The function starts with a comparison of the stack pointer and a
4603 // field in the TCB. This is followed by a jump.
4606 if (this->match_view(view
, view_size
, fnoffset
, cmp_insn
, cmp_insn_len
)
4607 && fnsize
> nop_len
+ 1)
4609 // We will call __morestack if the carry flag is set after this
4610 // comparison. We turn the comparison into an stc instruction
4612 view
[fnoffset
] = '\xf9';
4613 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, nop_len
);
4615 // lea NN(%rsp),%r10
4616 // lea NN(%rsp),%r11
4617 else if ((this->match_view(view
, view_size
, fnoffset
,
4618 lea_r10_insn
, lea_r10_insn_len
)
4619 || this->match_view(view
, view_size
, fnoffset
,
4620 lea_r11_insn
, lea_r11_insn_len
))
4623 // This is loading an offset from the stack pointer for a
4624 // comparison. The offset is negative, so we decrease the
4625 // offset by the amount of space we need for the stack. This
4626 // means we will avoid calling __morestack if there happens to
4627 // be plenty of space on the stack already.
4628 unsigned char* pval
= view
+ fnoffset
+ 4;
4629 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
4630 val
-= parameters
->options().split_stack_adjust_size();
4631 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
4635 if (!object
->has_no_split_stack())
4636 object
->error(_("failed to match split-stack sequence at "
4637 "section %u offset %0zx"),
4638 shndx
, static_cast<size_t>(fnoffset
));
4642 // We have to change the function so that it calls
4643 // __morestack_non_split instead of __morestack. The former will
4644 // allocate additional stack space.
4645 *from
= "__morestack";
4646 *to
= "__morestack_non_split";
4649 // The selector for x86_64 object files. Note this is never instantiated
4650 // directly. It's only used in Target_selector_x86_64_nacl, below.
4653 class Target_selector_x86_64
: public Target_selector_freebsd
4656 Target_selector_x86_64()
4657 : Target_selector_freebsd(elfcpp::EM_X86_64
, size
, false,
4659 ? "elf64-x86-64" : "elf32-x86-64"),
4661 ? "elf64-x86-64-freebsd"
4662 : "elf32-x86-64-freebsd"),
4663 (size
== 64 ? "elf_x86_64" : "elf32_x86_64"))
4667 do_instantiate_target()
4668 { return new Target_x86_64
<size
>(); }
4672 // NaCl variant. It uses different PLT contents.
4675 class Output_data_plt_x86_64_nacl
: public Output_data_plt_x86_64
<size
>
4678 Output_data_plt_x86_64_nacl(Layout
* layout
,
4679 Output_data_got
<64, false>* got
,
4680 Output_data_got_plt_x86_64
* got_plt
,
4681 Output_data_space
* got_irelative
)
4682 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
4683 got
, got_plt
, got_irelative
)
4686 Output_data_plt_x86_64_nacl(Layout
* layout
,
4687 Output_data_got
<64, false>* got
,
4688 Output_data_got_plt_x86_64
* got_plt
,
4689 Output_data_space
* got_irelative
,
4690 unsigned int plt_count
)
4691 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
4692 got
, got_plt
, got_irelative
,
4697 virtual unsigned int
4698 do_get_plt_entry_size() const
4699 { return plt_entry_size
; }
4702 do_add_eh_frame(Layout
* layout
)
4704 layout
->add_eh_frame_for_plt(this,
4705 this->plt_eh_frame_cie
,
4706 this->plt_eh_frame_cie_size
,
4708 plt_eh_frame_fde_size
);
4712 do_fill_first_plt_entry(unsigned char* pov
,
4713 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
4714 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
4716 virtual unsigned int
4717 do_fill_plt_entry(unsigned char* pov
,
4718 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4719 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4720 unsigned int got_offset
,
4721 unsigned int plt_offset
,
4722 unsigned int plt_index
);
4725 do_fill_tlsdesc_entry(unsigned char* pov
,
4726 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4727 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4728 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
4729 unsigned int tlsdesc_got_offset
,
4730 unsigned int plt_offset
);
4733 // The size of an entry in the PLT.
4734 static const int plt_entry_size
= 64;
4736 // The first entry in the PLT.
4737 static const unsigned char first_plt_entry
[plt_entry_size
];
4739 // Other entries in the PLT for an executable.
4740 static const unsigned char plt_entry
[plt_entry_size
];
4742 // The reserved TLSDESC entry in the PLT for an executable.
4743 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
4745 // The .eh_frame unwind information for the PLT.
4746 static const int plt_eh_frame_fde_size
= 32;
4747 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
4751 class Target_x86_64_nacl
: public Target_x86_64
<size
>
4754 Target_x86_64_nacl()
4755 : Target_x86_64
<size
>(&x86_64_nacl_info
)
4758 virtual Output_data_plt_x86_64
<size
>*
4759 do_make_data_plt(Layout
* layout
,
4760 Output_data_got
<64, false>* got
,
4761 Output_data_got_plt_x86_64
* got_plt
,
4762 Output_data_space
* got_irelative
)
4764 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
4768 virtual Output_data_plt_x86_64
<size
>*
4769 do_make_data_plt(Layout
* layout
,
4770 Output_data_got
<64, false>* got
,
4771 Output_data_got_plt_x86_64
* got_plt
,
4772 Output_data_space
* got_irelative
,
4773 unsigned int plt_count
)
4775 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
4781 do_code_fill(section_size_type length
) const;
4784 static const Target::Target_info x86_64_nacl_info
;
4788 const Target::Target_info Target_x86_64_nacl
<64>::x86_64_nacl_info
=
4791 false, // is_big_endian
4792 elfcpp::EM_X86_64
, // machine_code
4793 false, // has_make_symbol
4794 false, // has_resolve
4795 true, // has_code_fill
4796 true, // is_default_stack_executable
4797 true, // can_icf_inline_merge_sections
4799 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4800 0x20000, // default_text_segment_address
4801 0x10000, // abi_pagesize (overridable by -z max-page-size)
4802 0x10000, // common_pagesize (overridable by -z common-page-size)
4803 true, // isolate_execinstr
4804 0x10000000, // rosegment_gap
4805 elfcpp::SHN_UNDEF
, // small_common_shndx
4806 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
4807 0, // small_common_section_flags
4808 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
4809 NULL
, // attributes_section
4810 NULL
, // attributes_vendor
4811 "_start", // entry_symbol_name
4812 32, // hash_entry_size
4816 const Target::Target_info Target_x86_64_nacl
<32>::x86_64_nacl_info
=
4819 false, // is_big_endian
4820 elfcpp::EM_X86_64
, // machine_code
4821 false, // has_make_symbol
4822 false, // has_resolve
4823 true, // has_code_fill
4824 true, // is_default_stack_executable
4825 true, // can_icf_inline_merge_sections
4827 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4828 0x20000, // default_text_segment_address
4829 0x10000, // abi_pagesize (overridable by -z max-page-size)
4830 0x10000, // common_pagesize (overridable by -z common-page-size)
4831 true, // isolate_execinstr
4832 0x10000000, // rosegment_gap
4833 elfcpp::SHN_UNDEF
, // small_common_shndx
4834 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
4835 0, // small_common_section_flags
4836 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
4837 NULL
, // attributes_section
4838 NULL
, // attributes_vendor
4839 "_start", // entry_symbol_name
4840 32, // hash_entry_size
4843 #define NACLMASK 0xe0 // 32-byte alignment mask.
4845 // The first entry in the PLT.
4849 Output_data_plt_x86_64_nacl
<size
>::first_plt_entry
[plt_entry_size
] =
4851 0xff, 0x35, // pushq contents of memory address
4852 0, 0, 0, 0, // replaced with address of .got + 8
4853 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
4854 0, 0, 0, 0, // replaced with address of .got + 16
4855 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
4856 0x4d, 0x01, 0xfb, // add %r15, %r11
4857 0x41, 0xff, 0xe3, // jmpq *%r11
4859 // 9-byte nop sequence to pad out to the next 32-byte boundary.
4860 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4862 // 32 bytes of nop to pad out to the standard size
4863 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4864 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4865 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4866 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4867 0x66, // excess data32 prefix
4873 Output_data_plt_x86_64_nacl
<size
>::do_fill_first_plt_entry(
4875 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4876 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
4878 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4879 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4881 - (plt_address
+ 2 + 4)));
4882 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
4884 - (plt_address
+ 9 + 4)));
4887 // Subsequent entries in the PLT.
4891 Output_data_plt_x86_64_nacl
<size
>::plt_entry
[plt_entry_size
] =
4893 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
4894 0, 0, 0, 0, // replaced with address of symbol in .got
4895 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
4896 0x4d, 0x01, 0xfb, // add %r15, %r11
4897 0x41, 0xff, 0xe3, // jmpq *%r11
4899 // 15-byte nop sequence to pad out to the next 32-byte boundary.
4900 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4901 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4903 // Lazy GOT entries point here (32-byte aligned).
4904 0x68, // pushq immediate
4905 0, 0, 0, 0, // replaced with index into relocation table
4906 0xe9, // jmp relative
4907 0, 0, 0, 0, // replaced with offset to start of .plt0
4909 // 22 bytes of nop to pad out to the standard size.
4910 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4911 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4912 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
4917 Output_data_plt_x86_64_nacl
<size
>::do_fill_plt_entry(
4919 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4920 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4921 unsigned int got_offset
,
4922 unsigned int plt_offset
,
4923 unsigned int plt_index
)
4925 memcpy(pov
, plt_entry
, plt_entry_size
);
4926 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3,
4927 (got_address
+ got_offset
4928 - (plt_address
+ plt_offset
4931 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_index
);
4932 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 38,
4933 - (plt_offset
+ 38 + 4));
4938 // The reserved TLSDESC entry in the PLT.
4942 Output_data_plt_x86_64_nacl
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
4944 0xff, 0x35, // pushq x(%rip)
4945 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
4946 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
4947 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
4948 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
4949 0x4d, 0x01, 0xfb, // add %r15, %r11
4950 0x41, 0xff, 0xe3, // jmpq *%r11
4952 // 41 bytes of nop to pad out to the standard size.
4953 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4954 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4955 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4956 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4957 0x66, 0x66, // excess data32 prefixes
4958 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4963 Output_data_plt_x86_64_nacl
<size
>::do_fill_tlsdesc_entry(
4965 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4966 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4967 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
4968 unsigned int tlsdesc_got_offset
,
4969 unsigned int plt_offset
)
4971 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
4972 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4974 - (plt_address
+ plt_offset
4976 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
4978 + tlsdesc_got_offset
4979 - (plt_address
+ plt_offset
4983 // The .eh_frame unwind information for the PLT.
4987 Output_data_plt_x86_64_nacl
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4989 0, 0, 0, 0, // Replaced with offset to .plt.
4990 0, 0, 0, 0, // Replaced with size of .plt.
4991 0, // Augmentation size.
4992 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
4993 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4994 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
4995 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4996 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4997 13, // Block length.
4998 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
4999 elfcpp::DW_OP_breg16
, 0, // Push %rip.
5000 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
5001 elfcpp::DW_OP_and
, // & (%rip & 0x3f).
5002 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
5003 elfcpp::DW_OP_ge
, // >= ((%rip & 0x3f) >= 0x25)
5004 elfcpp::DW_OP_lit3
, // Push 3.
5005 elfcpp::DW_OP_shl
, // << (((%rip & 0x3f) >= 0x25) << 3)
5006 elfcpp::DW_OP_plus
, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5007 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
5011 // Return a string used to fill a code section with nops.
5012 // For NaCl, long NOPs are only valid if they do not cross
5013 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5016 Target_x86_64_nacl
<size
>::do_code_fill(section_size_type length
) const
5018 return std::string(length
, static_cast<char>(0x90));
5021 // The selector for x86_64-nacl object files.
5024 class Target_selector_x86_64_nacl
5025 : public Target_selector_nacl
<Target_selector_x86_64
<size
>,
5026 Target_x86_64_nacl
<size
> >
5029 Target_selector_x86_64_nacl()
5030 : Target_selector_nacl
<Target_selector_x86_64
<size
>,
5031 Target_x86_64_nacl
<size
> >("x86-64",
5033 ? "elf64-x86-64-nacl"
5034 : "elf32-x86-64-nacl",
5037 : "elf32_x86_64_nacl")
5041 Target_selector_x86_64_nacl
<64> target_selector_x86_64
;
5042 Target_selector_x86_64_nacl
<32> target_selector_x32
;
5044 } // End anonymous namespace.