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 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
820 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
822 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
823 section_size_type view_size
);
825 // Do a TLS General-Dynamic to Local-Exec transition.
827 tls_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
828 Output_segment
* tls_segment
,
829 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
830 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
832 section_size_type view_size
);
834 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
836 tls_desc_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
837 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
838 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
840 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
841 section_size_type view_size
);
843 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
845 tls_desc_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
846 Output_segment
* tls_segment
,
847 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
848 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
850 section_size_type view_size
);
852 // Do a TLS Local-Dynamic to Local-Exec transition.
854 tls_ld_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
855 Output_segment
* tls_segment
,
856 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
857 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
859 section_size_type view_size
);
861 // Do a TLS Initial-Exec to Local-Exec transition.
863 tls_ie_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
864 Output_segment
* tls_segment
,
865 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
866 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
868 section_size_type view_size
);
870 // This is set if we should skip the next reloc, which should be a
871 // PLT32 reloc against ___tls_get_addr.
872 bool skip_call_tls_get_addr_
;
875 // Check if relocation against this symbol is a candidate for
877 // mov foo@GOTPCREL(%rip), %reg
878 // to lea foo(%rip), %reg.
880 can_convert_mov_to_lea(const Symbol
* gsym
)
882 gold_assert(gsym
!= NULL
);
883 return (gsym
->type() != elfcpp::STT_GNU_IFUNC
884 && !gsym
->is_undefined ()
885 && !gsym
->is_from_dynobj()
886 && !gsym
->is_preemptible()
887 && (!parameters
->options().shared()
888 || (gsym
->visibility() != elfcpp::STV_DEFAULT
889 && gsym
->visibility() != elfcpp::STV_PROTECTED
)
890 || parameters
->options().Bsymbolic())
891 && strcmp(gsym
->name(), "_DYNAMIC") != 0);
894 // Adjust TLS relocation type based on the options and whether this
895 // is a local symbol.
896 static tls::Tls_optimization
897 optimize_tls_reloc(bool is_final
, int r_type
);
899 // Get the GOT section, creating it if necessary.
900 Output_data_got
<64, false>*
901 got_section(Symbol_table
*, Layout
*);
903 // Get the GOT PLT section.
904 Output_data_got_plt_x86_64
*
905 got_plt_section() const
907 gold_assert(this->got_plt_
!= NULL
);
908 return this->got_plt_
;
911 // Get the GOT section for TLSDESC entries.
912 Output_data_got
<64, false>*
913 got_tlsdesc_section() const
915 gold_assert(this->got_tlsdesc_
!= NULL
);
916 return this->got_tlsdesc_
;
919 // Create the PLT section.
921 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
923 // Create a PLT entry for a global symbol.
925 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
927 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
929 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
930 Sized_relobj_file
<size
, false>* relobj
,
931 unsigned int local_sym_index
);
933 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
935 define_tls_base_symbol(Symbol_table
*, Layout
*);
937 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
939 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
941 // Create a GOT entry for the TLS module index.
943 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
944 Sized_relobj_file
<size
, false>* object
);
946 // Get the PLT section.
947 Output_data_plt_x86_64
<size
>*
950 gold_assert(this->plt_
!= NULL
);
954 // Get the dynamic reloc section, creating it if necessary.
956 rela_dyn_section(Layout
*);
958 // Get the section to use for TLSDESC relocations.
960 rela_tlsdesc_section(Layout
*) const;
962 // Get the section to use for IRELATIVE relocations.
964 rela_irelative_section(Layout
*);
966 // Add a potential copy relocation.
968 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
969 Sized_relobj_file
<size
, false>* object
,
970 unsigned int shndx
, Output_section
* output_section
,
971 Symbol
* sym
, const elfcpp::Rela
<size
, false>& reloc
)
973 unsigned int r_type
= elfcpp::elf_r_type
<size
>(reloc
.get_r_info());
974 this->copy_relocs_
.copy_reloc(symtab
, layout
,
975 symtab
->get_sized_symbol
<size
>(sym
),
976 object
, shndx
, output_section
,
977 r_type
, reloc
.get_r_offset(),
978 reloc
.get_r_addend(),
979 this->rela_dyn_section(layout
));
982 // Information about this specific target which we pass to the
983 // general Target structure.
984 static const Target::Target_info x86_64_info
;
986 // The types of GOT entries needed for this platform.
987 // These values are exposed to the ABI in an incremental link.
988 // Do not renumber existing values without changing the version
989 // number of the .gnu_incremental_inputs section.
992 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
993 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
994 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
995 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
998 // This type is used as the argument to the target specific
999 // relocation routines. The only target specific reloc is
1000 // R_X86_64_TLSDESC against a local symbol.
1003 Tlsdesc_info(Sized_relobj_file
<size
, false>* a_object
, unsigned int a_r_sym
)
1004 : object(a_object
), r_sym(a_r_sym
)
1007 // The object in which the local symbol is defined.
1008 Sized_relobj_file
<size
, false>* object
;
1009 // The local symbol index in the object.
1014 Output_data_got
<64, false>* got_
;
1016 Output_data_plt_x86_64
<size
>* plt_
;
1017 // The GOT PLT section.
1018 Output_data_got_plt_x86_64
* got_plt_
;
1019 // The GOT section for IRELATIVE relocations.
1020 Output_data_space
* got_irelative_
;
1021 // The GOT section for TLSDESC relocations.
1022 Output_data_got
<64, false>* got_tlsdesc_
;
1023 // The _GLOBAL_OFFSET_TABLE_ symbol.
1024 Symbol
* global_offset_table_
;
1025 // The dynamic reloc section.
1026 Reloc_section
* rela_dyn_
;
1027 // The section to use for IRELATIVE relocs.
1028 Reloc_section
* rela_irelative_
;
1029 // Relocs saved to avoid a COPY reloc.
1030 Copy_relocs
<elfcpp::SHT_RELA
, size
, false> copy_relocs_
;
1031 // Offset of the GOT entry for the TLS module index.
1032 unsigned int got_mod_index_offset_
;
1033 // We handle R_X86_64_TLSDESC against a local symbol as a target
1034 // specific relocation. Here we store the object and local symbol
1035 // index for the relocation.
1036 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
1037 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1038 bool tls_base_symbol_defined_
;
1042 const Target::Target_info Target_x86_64
<64>::x86_64_info
=
1045 false, // is_big_endian
1046 elfcpp::EM_X86_64
, // machine_code
1047 false, // has_make_symbol
1048 false, // has_resolve
1049 true, // has_code_fill
1050 true, // is_default_stack_executable
1051 true, // can_icf_inline_merge_sections
1053 "/lib/ld64.so.1", // program interpreter
1054 0x400000, // default_text_segment_address
1055 0x1000, // abi_pagesize (overridable by -z max-page-size)
1056 0x1000, // common_pagesize (overridable by -z common-page-size)
1057 false, // isolate_execinstr
1059 elfcpp::SHN_UNDEF
, // small_common_shndx
1060 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1061 0, // small_common_section_flags
1062 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1063 NULL
, // attributes_section
1064 NULL
, // attributes_vendor
1065 "_start", // entry_symbol_name
1066 32, // hash_entry_size
1070 const Target::Target_info Target_x86_64
<32>::x86_64_info
=
1073 false, // is_big_endian
1074 elfcpp::EM_X86_64
, // machine_code
1075 false, // has_make_symbol
1076 false, // has_resolve
1077 true, // has_code_fill
1078 true, // is_default_stack_executable
1079 true, // can_icf_inline_merge_sections
1081 "/libx32/ldx32.so.1", // program interpreter
1082 0x400000, // default_text_segment_address
1083 0x1000, // abi_pagesize (overridable by -z max-page-size)
1084 0x1000, // common_pagesize (overridable by -z common-page-size)
1085 false, // isolate_execinstr
1087 elfcpp::SHN_UNDEF
, // small_common_shndx
1088 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1089 0, // small_common_section_flags
1090 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1091 NULL
, // attributes_section
1092 NULL
, // attributes_vendor
1093 "_start", // entry_symbol_name
1094 32, // hash_entry_size
1097 // This is called when a new output section is created. This is where
1098 // we handle the SHF_X86_64_LARGE.
1102 Target_x86_64
<size
>::do_new_output_section(Output_section
* os
) const
1104 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
1105 os
->set_is_large_section();
1108 // Get the GOT section, creating it if necessary.
1111 Output_data_got
<64, false>*
1112 Target_x86_64
<size
>::got_section(Symbol_table
* symtab
, Layout
* layout
)
1114 if (this->got_
== NULL
)
1116 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
1118 // When using -z now, we can treat .got.plt as a relro section.
1119 // Without -z now, it is modified after program startup by lazy
1121 bool is_got_plt_relro
= parameters
->options().now();
1122 Output_section_order got_order
= (is_got_plt_relro
1124 : ORDER_RELRO_LAST
);
1125 Output_section_order got_plt_order
= (is_got_plt_relro
1127 : ORDER_NON_RELRO_FIRST
);
1129 this->got_
= new Output_data_got
<64, false>();
1131 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1133 | elfcpp::SHF_WRITE
),
1134 this->got_
, got_order
, true);
1136 this->got_plt_
= new Output_data_got_plt_x86_64(layout
);
1137 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1139 | elfcpp::SHF_WRITE
),
1140 this->got_plt_
, got_plt_order
,
1143 // The first three entries are reserved.
1144 this->got_plt_
->set_current_data_size(3 * 8);
1146 if (!is_got_plt_relro
)
1148 // Those bytes can go into the relro segment.
1149 layout
->increase_relro(3 * 8);
1152 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1153 this->global_offset_table_
=
1154 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1155 Symbol_table::PREDEFINED
,
1157 0, 0, elfcpp::STT_OBJECT
,
1159 elfcpp::STV_HIDDEN
, 0,
1162 // If there are any IRELATIVE relocations, they get GOT entries
1163 // in .got.plt after the jump slot entries.
1164 this->got_irelative_
= new Output_data_space(8, "** GOT IRELATIVE PLT");
1165 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1167 | elfcpp::SHF_WRITE
),
1168 this->got_irelative_
,
1169 got_plt_order
, is_got_plt_relro
);
1171 // If there are any TLSDESC relocations, they get GOT entries in
1172 // .got.plt after the jump slot and IRELATIVE entries.
1173 this->got_tlsdesc_
= new Output_data_got
<64, false>();
1174 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1176 | elfcpp::SHF_WRITE
),
1178 got_plt_order
, is_got_plt_relro
);
1184 // Get the dynamic reloc section, creating it if necessary.
1187 typename Target_x86_64
<size
>::Reloc_section
*
1188 Target_x86_64
<size
>::rela_dyn_section(Layout
* layout
)
1190 if (this->rela_dyn_
== NULL
)
1192 gold_assert(layout
!= NULL
);
1193 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
1194 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1195 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
1196 ORDER_DYNAMIC_RELOCS
, false);
1198 return this->rela_dyn_
;
1201 // Get the section to use for IRELATIVE relocs, creating it if
1202 // necessary. These go in .rela.dyn, but only after all other dynamic
1203 // relocations. They need to follow the other dynamic relocations so
1204 // that they can refer to global variables initialized by those
1208 typename Target_x86_64
<size
>::Reloc_section
*
1209 Target_x86_64
<size
>::rela_irelative_section(Layout
* layout
)
1211 if (this->rela_irelative_
== NULL
)
1213 // Make sure we have already created the dynamic reloc section.
1214 this->rela_dyn_section(layout
);
1215 this->rela_irelative_
= new Reloc_section(false);
1216 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1217 elfcpp::SHF_ALLOC
, this->rela_irelative_
,
1218 ORDER_DYNAMIC_RELOCS
, false);
1219 gold_assert(this->rela_dyn_
->output_section()
1220 == this->rela_irelative_
->output_section());
1222 return this->rela_irelative_
;
1225 // Write the first three reserved words of the .got.plt section.
1226 // The remainder of the section is written while writing the PLT
1227 // in Output_data_plt_i386::do_write.
1230 Output_data_got_plt_x86_64::do_write(Output_file
* of
)
1232 // The first entry in the GOT is the address of the .dynamic section
1233 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1234 // We saved space for them when we created the section in
1235 // Target_x86_64::got_section.
1236 const off_t got_file_offset
= this->offset();
1237 gold_assert(this->data_size() >= 24);
1238 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 24);
1239 Output_section
* dynamic
= this->layout_
->dynamic_section();
1240 uint64_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1241 elfcpp::Swap
<64, false>::writeval(got_view
, dynamic_addr
);
1242 memset(got_view
+ 8, 0, 16);
1243 of
->write_output_view(got_file_offset
, 24, got_view
);
1246 // Initialize the PLT section.
1250 Output_data_plt_x86_64
<size
>::init(Layout
* layout
)
1252 this->rel_
= new Reloc_section(false);
1253 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1254 elfcpp::SHF_ALLOC
, this->rel_
,
1255 ORDER_DYNAMIC_PLT_RELOCS
, false);
1260 Output_data_plt_x86_64
<size
>::do_adjust_output_section(Output_section
* os
)
1262 os
->set_entsize(this->get_plt_entry_size());
1265 // Add an entry to the PLT.
1269 Output_data_plt_x86_64
<size
>::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1272 gold_assert(!gsym
->has_plt_offset());
1274 unsigned int plt_index
;
1276 section_offset_type got_offset
;
1278 unsigned int* pcount
;
1279 unsigned int offset
;
1280 unsigned int reserved
;
1281 Output_section_data_build
* got
;
1282 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1283 && gsym
->can_use_relative_reloc(false))
1285 pcount
= &this->irelative_count_
;
1288 got
= this->got_irelative_
;
1292 pcount
= &this->count_
;
1295 got
= this->got_plt_
;
1298 if (!this->is_data_size_valid())
1300 // Note that when setting the PLT offset for a non-IRELATIVE
1301 // entry we skip the initial reserved PLT entry.
1302 plt_index
= *pcount
+ offset
;
1303 plt_offset
= plt_index
* this->get_plt_entry_size();
1307 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1308 gold_assert(got_offset
== got
->current_data_size());
1310 // Every PLT entry needs a GOT entry which points back to the PLT
1311 // entry (this will be changed by the dynamic linker, normally
1312 // lazily when the function is called).
1313 got
->set_current_data_size(got_offset
+ 8);
1317 // FIXME: This is probably not correct for IRELATIVE relocs.
1319 // For incremental updates, find an available slot.
1320 plt_offset
= this->free_list_
.allocate(this->get_plt_entry_size(),
1321 this->get_plt_entry_size(), 0);
1322 if (plt_offset
== -1)
1323 gold_fallback(_("out of patch space (PLT);"
1324 " relink with --incremental-full"));
1326 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1327 // can be calculated from the PLT index, adjusting for the three
1328 // reserved entries at the beginning of the GOT.
1329 plt_index
= plt_offset
/ this->get_plt_entry_size() - 1;
1330 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1333 gsym
->set_plt_offset(plt_offset
);
1335 // Every PLT entry needs a reloc.
1336 this->add_relocation(symtab
, layout
, gsym
, got_offset
);
1338 // Note that we don't need to save the symbol. The contents of the
1339 // PLT are independent of which symbols are used. The symbols only
1340 // appear in the relocations.
1343 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1348 Output_data_plt_x86_64
<size
>::add_local_ifunc_entry(
1349 Symbol_table
* symtab
,
1351 Sized_relobj_file
<size
, false>* relobj
,
1352 unsigned int local_sym_index
)
1354 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1355 ++this->irelative_count_
;
1357 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1359 // Every PLT entry needs a GOT entry which points back to the PLT
1361 this->got_irelative_
->set_current_data_size(got_offset
+ 8);
1363 // Every PLT entry needs a reloc.
1364 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1365 rela
->add_symbolless_local_addend(relobj
, local_sym_index
,
1366 elfcpp::R_X86_64_IRELATIVE
,
1367 this->got_irelative_
, got_offset
, 0);
1372 // Add the relocation for a PLT entry.
1376 Output_data_plt_x86_64
<size
>::add_relocation(Symbol_table
* symtab
,
1379 unsigned int got_offset
)
1381 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1382 && gsym
->can_use_relative_reloc(false))
1384 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1385 rela
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
1386 this->got_irelative_
, got_offset
, 0);
1390 gsym
->set_needs_dynsym_entry();
1391 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
1396 // Return where the TLSDESC relocations should go, creating it if
1397 // necessary. These follow the JUMP_SLOT relocations.
1400 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1401 Output_data_plt_x86_64
<size
>::rela_tlsdesc(Layout
* layout
)
1403 if (this->tlsdesc_rel_
== NULL
)
1405 this->tlsdesc_rel_
= new Reloc_section(false);
1406 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1407 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
1408 ORDER_DYNAMIC_PLT_RELOCS
, false);
1409 gold_assert(this->tlsdesc_rel_
->output_section()
1410 == this->rel_
->output_section());
1412 return this->tlsdesc_rel_
;
1415 // Return where the IRELATIVE relocations should go in the PLT. These
1416 // follow the JUMP_SLOT and the TLSDESC relocations.
1419 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1420 Output_data_plt_x86_64
<size
>::rela_irelative(Symbol_table
* symtab
,
1423 if (this->irelative_rel_
== NULL
)
1425 // Make sure we have a place for the TLSDESC relocations, in
1426 // case we see any later on.
1427 this->rela_tlsdesc(layout
);
1428 this->irelative_rel_
= new Reloc_section(false);
1429 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1430 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1431 ORDER_DYNAMIC_PLT_RELOCS
, false);
1432 gold_assert(this->irelative_rel_
->output_section()
1433 == this->rel_
->output_section());
1435 if (parameters
->doing_static_link())
1437 // A statically linked executable will only have a .rela.plt
1438 // section to hold R_X86_64_IRELATIVE relocs for
1439 // STT_GNU_IFUNC symbols. The library will use these
1440 // symbols to locate the IRELATIVE relocs at program startup
1442 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
1443 Symbol_table::PREDEFINED
,
1444 this->irelative_rel_
, 0, 0,
1445 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1446 elfcpp::STV_HIDDEN
, 0, false, true);
1447 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
1448 Symbol_table::PREDEFINED
,
1449 this->irelative_rel_
, 0, 0,
1450 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1451 elfcpp::STV_HIDDEN
, 0, true, true);
1454 return this->irelative_rel_
;
1457 // Return the PLT address to use for a global symbol.
1461 Output_data_plt_x86_64
<size
>::address_for_global(const Symbol
* gsym
)
1463 uint64_t offset
= 0;
1464 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1465 && gsym
->can_use_relative_reloc(false))
1466 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1467 return this->address() + offset
+ gsym
->plt_offset();
1470 // Return the PLT address to use for a local symbol. These are always
1471 // IRELATIVE relocs.
1475 Output_data_plt_x86_64
<size
>::address_for_local(const Relobj
* object
,
1478 return (this->address()
1479 + (this->count_
+ 1) * this->get_plt_entry_size()
1480 + object
->local_plt_offset(r_sym
));
1483 // Set the final size.
1486 Output_data_plt_x86_64
<size
>::set_final_data_size()
1488 unsigned int count
= this->count_
+ this->irelative_count_
;
1489 if (this->has_tlsdesc_entry())
1491 this->set_data_size((count
+ 1) * this->get_plt_entry_size());
1494 // The first entry in the PLT for an executable.
1498 Output_data_plt_x86_64_standard
<size
>::first_plt_entry
[plt_entry_size
] =
1500 // From AMD64 ABI Draft 0.98, page 76
1501 0xff, 0x35, // pushq contents of memory address
1502 0, 0, 0, 0, // replaced with address of .got + 8
1503 0xff, 0x25, // jmp indirect
1504 0, 0, 0, 0, // replaced with address of .got + 16
1505 0x90, 0x90, 0x90, 0x90 // noop (x4)
1510 Output_data_plt_x86_64_standard
<size
>::do_fill_first_plt_entry(
1512 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1513 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
1515 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1516 // We do a jmp relative to the PC at the end of this instruction.
1517 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1519 - (plt_address
+ 6)));
1520 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
1522 - (plt_address
+ 12)));
1525 // Subsequent entries in the PLT for an executable.
1529 Output_data_plt_x86_64_standard
<size
>::plt_entry
[plt_entry_size
] =
1531 // From AMD64 ABI Draft 0.98, page 76
1532 0xff, 0x25, // jmpq indirect
1533 0, 0, 0, 0, // replaced with address of symbol in .got
1534 0x68, // pushq immediate
1535 0, 0, 0, 0, // replaced with offset into relocation table
1536 0xe9, // jmpq relative
1537 0, 0, 0, 0 // replaced with offset to start of .plt
1542 Output_data_plt_x86_64_standard
<size
>::do_fill_plt_entry(
1544 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1545 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
1546 unsigned int got_offset
,
1547 unsigned int plt_offset
,
1548 unsigned int plt_index
)
1550 // Check PC-relative offset overflow in PLT entry.
1551 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
1552 - (plt_address
+ plt_offset
+ 6));
1553 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
1554 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1557 memcpy(pov
, plt_entry
, plt_entry_size
);
1558 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1559 plt_got_pcrel_offset
);
1561 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
1562 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
1563 - (plt_offset
+ plt_entry_size
));
1568 // The reserved TLSDESC entry in the PLT for an executable.
1572 Output_data_plt_x86_64_standard
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
1574 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1575 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1576 0xff, 0x35, // pushq x(%rip)
1577 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1578 0xff, 0x25, // jmpq *y(%rip)
1579 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1586 Output_data_plt_x86_64_standard
<size
>::do_fill_tlsdesc_entry(
1588 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1589 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
1590 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
1591 unsigned int tlsdesc_got_offset
,
1592 unsigned int plt_offset
)
1594 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1595 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1597 - (plt_address
+ plt_offset
1599 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
1601 + tlsdesc_got_offset
1602 - (plt_address
+ plt_offset
1606 // The .eh_frame unwind information for the PLT.
1610 Output_data_plt_x86_64
<size
>::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1613 'z', // Augmentation: augmentation size included.
1614 'R', // Augmentation: FDE encoding included.
1615 '\0', // End of augmentation string.
1616 1, // Code alignment factor.
1617 0x78, // Data alignment factor.
1618 16, // Return address column.
1619 1, // Augmentation size.
1620 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1621 | elfcpp::DW_EH_PE_sdata4
),
1622 elfcpp::DW_CFA_def_cfa
, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1623 elfcpp::DW_CFA_offset
+ 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1624 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1630 Output_data_plt_x86_64_standard
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1632 0, 0, 0, 0, // Replaced with offset to .plt.
1633 0, 0, 0, 0, // Replaced with size of .plt.
1634 0, // Augmentation size.
1635 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
1636 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1637 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
1638 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1639 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1640 11, // Block length.
1641 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
1642 elfcpp::DW_OP_breg16
, 0, // Push %rip.
1643 elfcpp::DW_OP_lit15
, // Push 0xf.
1644 elfcpp::DW_OP_and
, // & (%rip & 0xf).
1645 elfcpp::DW_OP_lit11
, // Push 0xb.
1646 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 0xb)
1647 elfcpp::DW_OP_lit3
, // Push 3.
1648 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 0xb) << 3)
1649 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1650 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1656 // Write out the PLT. This uses the hand-coded instructions above,
1657 // and adjusts them as needed. This is specified by the AMD64 ABI.
1661 Output_data_plt_x86_64
<size
>::do_write(Output_file
* of
)
1663 const off_t offset
= this->offset();
1664 const section_size_type oview_size
=
1665 convert_to_section_size_type(this->data_size());
1666 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1668 const off_t got_file_offset
= this->got_plt_
->offset();
1669 gold_assert(parameters
->incremental_update()
1670 || (got_file_offset
+ this->got_plt_
->data_size()
1671 == this->got_irelative_
->offset()));
1672 const section_size_type got_size
=
1673 convert_to_section_size_type(this->got_plt_
->data_size()
1674 + this->got_irelative_
->data_size());
1675 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1678 unsigned char* pov
= oview
;
1680 // The base address of the .plt section.
1681 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
= this->address();
1682 // The base address of the .got section.
1683 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
= this->got_
->address();
1684 // The base address of the PLT portion of the .got section,
1685 // which is where the GOT pointer will point, and where the
1686 // three reserved GOT entries are located.
1687 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
1688 = this->got_plt_
->address();
1690 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
1691 pov
+= this->get_plt_entry_size();
1693 // The first three entries in the GOT are reserved, and are written
1694 // by Output_data_got_plt_x86_64::do_write.
1695 unsigned char* got_pov
= got_view
+ 24;
1697 unsigned int plt_offset
= this->get_plt_entry_size();
1698 unsigned int got_offset
= 24;
1699 const unsigned int count
= this->count_
+ this->irelative_count_
;
1700 for (unsigned int plt_index
= 0;
1703 pov
+= this->get_plt_entry_size(),
1705 plt_offset
+= this->get_plt_entry_size(),
1708 // Set and adjust the PLT entry itself.
1709 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1710 got_address
, plt_address
,
1711 got_offset
, plt_offset
,
1714 // Set the entry in the GOT.
1715 elfcpp::Swap
<64, false>::writeval(got_pov
,
1716 plt_address
+ plt_offset
+ lazy_offset
);
1719 if (this->has_tlsdesc_entry())
1721 // Set and adjust the reserved TLSDESC PLT entry.
1722 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
1723 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
1724 tlsdesc_got_offset
, plt_offset
);
1725 pov
+= this->get_plt_entry_size();
1728 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1729 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1731 of
->write_output_view(offset
, oview_size
, oview
);
1732 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1735 // Create the PLT section.
1739 Target_x86_64
<size
>::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1741 if (this->plt_
== NULL
)
1743 // Create the GOT sections first.
1744 this->got_section(symtab
, layout
);
1746 this->plt_
= this->make_data_plt(layout
, this->got_
, this->got_plt_
,
1747 this->got_irelative_
);
1749 // Add unwind information if requested.
1750 if (parameters
->options().ld_generated_unwind_info())
1751 this->plt_
->add_eh_frame(layout
);
1753 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1755 | elfcpp::SHF_EXECINSTR
),
1756 this->plt_
, ORDER_PLT
, false);
1758 // Make the sh_info field of .rela.plt point to .plt.
1759 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1760 rela_plt_os
->set_info_section(this->plt_
->output_section());
1764 // Return the section for TLSDESC relocations.
1767 typename Target_x86_64
<size
>::Reloc_section
*
1768 Target_x86_64
<size
>::rela_tlsdesc_section(Layout
* layout
) const
1770 return this->plt_section()->rela_tlsdesc(layout
);
1773 // Create a PLT entry for a global symbol.
1777 Target_x86_64
<size
>::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1780 if (gsym
->has_plt_offset())
1783 if (this->plt_
== NULL
)
1784 this->make_plt_section(symtab
, layout
);
1786 this->plt_
->add_entry(symtab
, layout
, gsym
);
1789 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1793 Target_x86_64
<size
>::make_local_ifunc_plt_entry(
1794 Symbol_table
* symtab
, Layout
* layout
,
1795 Sized_relobj_file
<size
, false>* relobj
,
1796 unsigned int local_sym_index
)
1798 if (relobj
->local_has_plt_offset(local_sym_index
))
1800 if (this->plt_
== NULL
)
1801 this->make_plt_section(symtab
, layout
);
1802 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1805 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1808 // Return the number of entries in the PLT.
1812 Target_x86_64
<size
>::plt_entry_count() const
1814 if (this->plt_
== NULL
)
1816 return this->plt_
->entry_count();
1819 // Return the offset of the first non-reserved PLT entry.
1823 Target_x86_64
<size
>::first_plt_entry_offset() const
1825 if (this->plt_
== NULL
)
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 if (this->plt_
== NULL
)
1838 return this->plt_
->get_plt_entry_size();
1841 // Create the GOT and PLT sections for an incremental update.
1844 Output_data_got_base
*
1845 Target_x86_64
<size
>::init_got_plt_for_update(Symbol_table
* symtab
,
1847 unsigned int got_count
,
1848 unsigned int plt_count
)
1850 gold_assert(this->got_
== NULL
);
1852 this->got_
= new Output_data_got
<64, false>(got_count
* 8);
1853 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1855 | elfcpp::SHF_WRITE
),
1856 this->got_
, ORDER_RELRO_LAST
,
1859 // Add the three reserved entries.
1860 this->got_plt_
= new Output_data_got_plt_x86_64(layout
, (plt_count
+ 3) * 8);
1861 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1863 | elfcpp::SHF_WRITE
),
1864 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
1867 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1868 this->global_offset_table_
=
1869 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1870 Symbol_table::PREDEFINED
,
1872 0, 0, elfcpp::STT_OBJECT
,
1874 elfcpp::STV_HIDDEN
, 0,
1877 // If there are any TLSDESC relocations, they get GOT entries in
1878 // .got.plt after the jump slot entries.
1879 // FIXME: Get the count for TLSDESC entries.
1880 this->got_tlsdesc_
= new Output_data_got
<64, false>(0);
1881 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1882 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
1884 ORDER_NON_RELRO_FIRST
, false);
1886 // If there are any IRELATIVE relocations, they get GOT entries in
1887 // .got.plt after the jump slot and TLSDESC entries.
1888 this->got_irelative_
= new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1889 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1890 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
1891 this->got_irelative_
,
1892 ORDER_NON_RELRO_FIRST
, false);
1894 // Create the PLT section.
1895 this->plt_
= this->make_data_plt(layout
, this->got_
,
1897 this->got_irelative_
,
1900 // Add unwind information if requested.
1901 if (parameters
->options().ld_generated_unwind_info())
1902 this->plt_
->add_eh_frame(layout
);
1904 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1905 elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
,
1906 this->plt_
, ORDER_PLT
, false);
1908 // Make the sh_info field of .rela.plt point to .plt.
1909 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1910 rela_plt_os
->set_info_section(this->plt_
->output_section());
1912 // Create the rela_dyn section.
1913 this->rela_dyn_section(layout
);
1918 // Reserve a GOT entry for a local symbol, and regenerate any
1919 // necessary dynamic relocations.
1923 Target_x86_64
<size
>::reserve_local_got_entry(
1924 unsigned int got_index
,
1925 Sized_relobj
<size
, false>* obj
,
1927 unsigned int got_type
)
1929 unsigned int got_offset
= got_index
* 8;
1930 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
1932 this->got_
->reserve_local(got_index
, obj
, r_sym
, got_type
);
1935 case GOT_TYPE_STANDARD
:
1936 if (parameters
->options().output_is_position_independent())
1937 rela_dyn
->add_local_relative(obj
, r_sym
, elfcpp::R_X86_64_RELATIVE
,
1938 this->got_
, got_offset
, 0, false);
1940 case GOT_TYPE_TLS_OFFSET
:
1941 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_TPOFF64
,
1942 this->got_
, got_offset
, 0);
1944 case GOT_TYPE_TLS_PAIR
:
1945 this->got_
->reserve_slot(got_index
+ 1);
1946 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_DTPMOD64
,
1947 this->got_
, got_offset
, 0);
1949 case GOT_TYPE_TLS_DESC
:
1950 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1951 // this->got_->reserve_slot(got_index + 1);
1952 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1953 // this->got_, got_offset, 0);
1960 // Reserve a GOT entry for a global symbol, and regenerate any
1961 // necessary dynamic relocations.
1965 Target_x86_64
<size
>::reserve_global_got_entry(unsigned int got_index
,
1967 unsigned int got_type
)
1969 unsigned int got_offset
= got_index
* 8;
1970 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
1972 this->got_
->reserve_global(got_index
, gsym
, got_type
);
1975 case GOT_TYPE_STANDARD
:
1976 if (!gsym
->final_value_is_known())
1978 if (gsym
->is_from_dynobj()
1979 || gsym
->is_undefined()
1980 || gsym
->is_preemptible()
1981 || gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1982 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
,
1983 this->got_
, got_offset
, 0);
1985 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1986 this->got_
, got_offset
, 0, false);
1989 case GOT_TYPE_TLS_OFFSET
:
1990 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TPOFF64
,
1991 this->got_
, got_offset
, 0, false);
1993 case GOT_TYPE_TLS_PAIR
:
1994 this->got_
->reserve_slot(got_index
+ 1);
1995 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPMOD64
,
1996 this->got_
, got_offset
, 0, false);
1997 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPOFF64
,
1998 this->got_
, got_offset
+ 8, 0, false);
2000 case GOT_TYPE_TLS_DESC
:
2001 this->got_
->reserve_slot(got_index
+ 1);
2002 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TLSDESC
,
2003 this->got_
, got_offset
, 0, false);
2010 // Register an existing PLT entry for a global symbol.
2014 Target_x86_64
<size
>::register_global_plt_entry(Symbol_table
* symtab
,
2016 unsigned int plt_index
,
2019 gold_assert(this->plt_
!= NULL
);
2020 gold_assert(!gsym
->has_plt_offset());
2022 this->plt_
->reserve_slot(plt_index
);
2024 gsym
->set_plt_offset((plt_index
+ 1) * this->plt_entry_size());
2026 unsigned int got_offset
= (plt_index
+ 3) * 8;
2027 this->plt_
->add_relocation(symtab
, layout
, gsym
, got_offset
);
2030 // Force a COPY relocation for a given symbol.
2034 Target_x86_64
<size
>::emit_copy_reloc(
2035 Symbol_table
* symtab
, Symbol
* sym
, Output_section
* os
, off_t offset
)
2037 this->copy_relocs_
.emit_copy_reloc(symtab
,
2038 symtab
->get_sized_symbol
<size
>(sym
),
2041 this->rela_dyn_section(NULL
));
2044 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2048 Target_x86_64
<size
>::define_tls_base_symbol(Symbol_table
* symtab
,
2051 if (this->tls_base_symbol_defined_
)
2054 Output_segment
* tls_segment
= layout
->tls_segment();
2055 if (tls_segment
!= NULL
)
2057 bool is_exec
= parameters
->options().output_is_executable();
2058 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
2059 Symbol_table::PREDEFINED
,
2063 elfcpp::STV_HIDDEN
, 0,
2065 ? Symbol::SEGMENT_END
2066 : Symbol::SEGMENT_START
),
2069 this->tls_base_symbol_defined_
= true;
2072 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2076 Target_x86_64
<size
>::reserve_tlsdesc_entries(Symbol_table
* symtab
,
2079 if (this->plt_
== NULL
)
2080 this->make_plt_section(symtab
, layout
);
2082 if (!this->plt_
->has_tlsdesc_entry())
2084 // Allocate the TLSDESC_GOT entry.
2085 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
2086 unsigned int got_offset
= got
->add_constant(0);
2088 // Allocate the TLSDESC_PLT entry.
2089 this->plt_
->reserve_tlsdesc_entry(got_offset
);
2093 // Create a GOT entry for the TLS module index.
2097 Target_x86_64
<size
>::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
2098 Sized_relobj_file
<size
, false>* object
)
2100 if (this->got_mod_index_offset_
== -1U)
2102 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
2103 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
2104 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
2105 unsigned int got_offset
= got
->add_constant(0);
2106 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
2108 got
->add_constant(0);
2109 this->got_mod_index_offset_
= got_offset
;
2111 return this->got_mod_index_offset_
;
2114 // Optimize the TLS relocation type based on what we know about the
2115 // symbol. IS_FINAL is true if the final address of this symbol is
2116 // known at link time.
2119 tls::Tls_optimization
2120 Target_x86_64
<size
>::optimize_tls_reloc(bool is_final
, int r_type
)
2122 // If we are generating a shared library, then we can't do anything
2124 if (parameters
->options().shared())
2125 return tls::TLSOPT_NONE
;
2129 case elfcpp::R_X86_64_TLSGD
:
2130 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2131 case elfcpp::R_X86_64_TLSDESC_CALL
:
2132 // These are General-Dynamic which permits fully general TLS
2133 // access. Since we know that we are generating an executable,
2134 // we can convert this to Initial-Exec. If we also know that
2135 // this is a local symbol, we can further switch to Local-Exec.
2137 return tls::TLSOPT_TO_LE
;
2138 return tls::TLSOPT_TO_IE
;
2140 case elfcpp::R_X86_64_TLSLD
:
2141 // This is Local-Dynamic, which refers to a local symbol in the
2142 // dynamic TLS block. Since we know that we generating an
2143 // executable, we can switch to Local-Exec.
2144 return tls::TLSOPT_TO_LE
;
2146 case elfcpp::R_X86_64_DTPOFF32
:
2147 case elfcpp::R_X86_64_DTPOFF64
:
2148 // Another Local-Dynamic reloc.
2149 return tls::TLSOPT_TO_LE
;
2151 case elfcpp::R_X86_64_GOTTPOFF
:
2152 // These are Initial-Exec relocs which get the thread offset
2153 // from the GOT. If we know that we are linking against the
2154 // local symbol, we can switch to Local-Exec, which links the
2155 // thread offset into the instruction.
2157 return tls::TLSOPT_TO_LE
;
2158 return tls::TLSOPT_NONE
;
2160 case elfcpp::R_X86_64_TPOFF32
:
2161 // When we already have Local-Exec, there is nothing further we
2163 return tls::TLSOPT_NONE
;
2170 // Get the Reference_flags for a particular relocation.
2174 Target_x86_64
<size
>::Scan::get_reference_flags(unsigned int r_type
)
2178 case elfcpp::R_X86_64_NONE
:
2179 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2180 case elfcpp::R_X86_64_GNU_VTENTRY
:
2181 case elfcpp::R_X86_64_GOTPC32
:
2182 case elfcpp::R_X86_64_GOTPC64
:
2183 // No symbol reference.
2186 case elfcpp::R_X86_64_64
:
2187 case elfcpp::R_X86_64_32
:
2188 case elfcpp::R_X86_64_32S
:
2189 case elfcpp::R_X86_64_16
:
2190 case elfcpp::R_X86_64_8
:
2191 return Symbol::ABSOLUTE_REF
;
2193 case elfcpp::R_X86_64_PC64
:
2194 case elfcpp::R_X86_64_PC32
:
2195 case elfcpp::R_X86_64_PC32_BND
:
2196 case elfcpp::R_X86_64_PC16
:
2197 case elfcpp::R_X86_64_PC8
:
2198 case elfcpp::R_X86_64_GOTOFF64
:
2199 return Symbol::RELATIVE_REF
;
2201 case elfcpp::R_X86_64_PLT32
:
2202 case elfcpp::R_X86_64_PLT32_BND
:
2203 case elfcpp::R_X86_64_PLTOFF64
:
2204 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
2206 case elfcpp::R_X86_64_GOT64
:
2207 case elfcpp::R_X86_64_GOT32
:
2208 case elfcpp::R_X86_64_GOTPCREL64
:
2209 case elfcpp::R_X86_64_GOTPCREL
:
2210 case elfcpp::R_X86_64_GOTPCRELX
:
2211 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2212 case elfcpp::R_X86_64_GOTPLT64
:
2214 return Symbol::ABSOLUTE_REF
;
2216 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2217 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2218 case elfcpp::R_X86_64_TLSDESC_CALL
:
2219 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2220 case elfcpp::R_X86_64_DTPOFF32
:
2221 case elfcpp::R_X86_64_DTPOFF64
:
2222 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2223 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2224 return Symbol::TLS_REF
;
2226 case elfcpp::R_X86_64_COPY
:
2227 case elfcpp::R_X86_64_GLOB_DAT
:
2228 case elfcpp::R_X86_64_JUMP_SLOT
:
2229 case elfcpp::R_X86_64_RELATIVE
:
2230 case elfcpp::R_X86_64_IRELATIVE
:
2231 case elfcpp::R_X86_64_TPOFF64
:
2232 case elfcpp::R_X86_64_DTPMOD64
:
2233 case elfcpp::R_X86_64_TLSDESC
:
2234 case elfcpp::R_X86_64_SIZE32
:
2235 case elfcpp::R_X86_64_SIZE64
:
2237 // Not expected. We will give an error later.
2242 // Report an unsupported relocation against a local symbol.
2246 Target_x86_64
<size
>::Scan::unsupported_reloc_local(
2247 Sized_relobj_file
<size
, false>* object
,
2248 unsigned int r_type
)
2250 gold_error(_("%s: unsupported reloc %u against local symbol"),
2251 object
->name().c_str(), r_type
);
2254 // We are about to emit a dynamic relocation of type R_TYPE. If the
2255 // dynamic linker does not support it, issue an error. The GNU linker
2256 // only issues a non-PIC error for an allocated read-only section.
2257 // Here we know the section is allocated, but we don't know that it is
2258 // read-only. But we check for all the relocation types which the
2259 // glibc dynamic linker supports, so it seems appropriate to issue an
2260 // error even if the section is not read-only. If GSYM is not NULL,
2261 // it is the symbol the relocation is against; if it is NULL, the
2262 // relocation is against a local symbol.
2266 Target_x86_64
<size
>::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
,
2271 // These are the relocation types supported by glibc for x86_64
2272 // which should always work.
2273 case elfcpp::R_X86_64_RELATIVE
:
2274 case elfcpp::R_X86_64_IRELATIVE
:
2275 case elfcpp::R_X86_64_GLOB_DAT
:
2276 case elfcpp::R_X86_64_JUMP_SLOT
:
2277 case elfcpp::R_X86_64_DTPMOD64
:
2278 case elfcpp::R_X86_64_DTPOFF64
:
2279 case elfcpp::R_X86_64_TPOFF64
:
2280 case elfcpp::R_X86_64_64
:
2281 case elfcpp::R_X86_64_COPY
:
2284 // glibc supports these reloc types, but they can overflow.
2285 case elfcpp::R_X86_64_PC32
:
2286 case elfcpp::R_X86_64_PC32_BND
:
2287 // A PC relative reference is OK against a local symbol or if
2288 // the symbol is defined locally.
2290 || (!gsym
->is_from_dynobj()
2291 && !gsym
->is_undefined()
2292 && !gsym
->is_preemptible()))
2295 case elfcpp::R_X86_64_32
:
2296 // R_X86_64_32 is OK for x32.
2297 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
2299 if (this->issued_non_pic_error_
)
2301 gold_assert(parameters
->options().output_is_position_independent());
2303 object
->error(_("requires dynamic R_X86_64_32 reloc which may "
2304 "overflow at runtime; recompile with -fPIC"));
2310 case elfcpp::R_X86_64_32
:
2311 r_name
= "R_X86_64_32";
2313 case elfcpp::R_X86_64_PC32
:
2314 r_name
= "R_X86_64_PC32";
2316 case elfcpp::R_X86_64_PC32_BND
:
2317 r_name
= "R_X86_64_PC32_BND";
2323 object
->error(_("requires dynamic %s reloc against '%s' "
2324 "which may overflow at runtime; recompile "
2326 r_name
, gsym
->name());
2328 this->issued_non_pic_error_
= true;
2332 // This prevents us from issuing more than one error per reloc
2333 // section. But we can still wind up issuing more than one
2334 // error per object file.
2335 if (this->issued_non_pic_error_
)
2337 gold_assert(parameters
->options().output_is_position_independent());
2338 object
->error(_("requires unsupported dynamic reloc %u; "
2339 "recompile with -fPIC"),
2341 this->issued_non_pic_error_
= true;
2344 case elfcpp::R_X86_64_NONE
:
2349 // Return whether we need to make a PLT entry for a relocation of the
2350 // given type against a STT_GNU_IFUNC symbol.
2354 Target_x86_64
<size
>::Scan::reloc_needs_plt_for_ifunc(
2355 Sized_relobj_file
<size
, false>* object
,
2356 unsigned int r_type
)
2358 int flags
= Scan::get_reference_flags(r_type
);
2359 if (flags
& Symbol::TLS_REF
)
2360 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2361 object
->name().c_str(), r_type
);
2365 // Scan a relocation for a local symbol.
2369 Target_x86_64
<size
>::Scan::local(Symbol_table
* symtab
,
2371 Target_x86_64
<size
>* target
,
2372 Sized_relobj_file
<size
, false>* object
,
2373 unsigned int data_shndx
,
2374 Output_section
* output_section
,
2375 const elfcpp::Rela
<size
, false>& reloc
,
2376 unsigned int r_type
,
2377 const elfcpp::Sym
<size
, false>& lsym
,
2383 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2384 bool is_ifunc
= lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
;
2385 if (is_ifunc
&& this->reloc_needs_plt_for_ifunc(object
, r_type
))
2387 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2388 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
2393 case elfcpp::R_X86_64_NONE
:
2394 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2395 case elfcpp::R_X86_64_GNU_VTENTRY
:
2398 case elfcpp::R_X86_64_64
:
2399 // If building a shared library (or a position-independent
2400 // executable), we need to create a dynamic relocation for this
2401 // location. The relocation applied at link time will apply the
2402 // link-time value, so we flag the location with an
2403 // R_X86_64_RELATIVE relocation so the dynamic loader can
2404 // relocate it easily.
2405 if (parameters
->options().output_is_position_independent())
2407 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2408 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2409 rela_dyn
->add_local_relative(object
, r_sym
,
2411 ? elfcpp::R_X86_64_RELATIVE64
2412 : elfcpp::R_X86_64_RELATIVE
),
2413 output_section
, data_shndx
,
2414 reloc
.get_r_offset(),
2415 reloc
.get_r_addend(), is_ifunc
);
2419 case elfcpp::R_X86_64_32
:
2420 case elfcpp::R_X86_64_32S
:
2421 case elfcpp::R_X86_64_16
:
2422 case elfcpp::R_X86_64_8
:
2423 // If building a shared library (or a position-independent
2424 // executable), we need to create a dynamic relocation for this
2425 // location. We can't use an R_X86_64_RELATIVE relocation
2426 // because that is always a 64-bit relocation.
2427 if (parameters
->options().output_is_position_independent())
2429 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2430 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
2432 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2433 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2434 rela_dyn
->add_local_relative(object
, r_sym
,
2435 elfcpp::R_X86_64_RELATIVE
,
2436 output_section
, data_shndx
,
2437 reloc
.get_r_offset(),
2438 reloc
.get_r_addend(), is_ifunc
);
2442 this->check_non_pic(object
, r_type
, NULL
);
2444 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2445 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2446 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
2447 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
2448 data_shndx
, reloc
.get_r_offset(),
2449 reloc
.get_r_addend());
2452 gold_assert(lsym
.get_st_value() == 0);
2453 unsigned int shndx
= lsym
.get_st_shndx();
2455 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
2458 object
->error(_("section symbol %u has bad shndx %u"),
2461 rela_dyn
->add_local_section(object
, shndx
,
2462 r_type
, output_section
,
2463 data_shndx
, reloc
.get_r_offset(),
2464 reloc
.get_r_addend());
2469 case elfcpp::R_X86_64_PC64
:
2470 case elfcpp::R_X86_64_PC32
:
2471 case elfcpp::R_X86_64_PC32_BND
:
2472 case elfcpp::R_X86_64_PC16
:
2473 case elfcpp::R_X86_64_PC8
:
2476 case elfcpp::R_X86_64_PLT32
:
2477 case elfcpp::R_X86_64_PLT32_BND
:
2478 // Since we know this is a local symbol, we can handle this as a
2482 case elfcpp::R_X86_64_GOTPC32
:
2483 case elfcpp::R_X86_64_GOTOFF64
:
2484 case elfcpp::R_X86_64_GOTPC64
:
2485 case elfcpp::R_X86_64_PLTOFF64
:
2486 // We need a GOT section.
2487 target
->got_section(symtab
, layout
);
2488 // For PLTOFF64, we'd normally want a PLT section, but since we
2489 // know this is a local symbol, no PLT is needed.
2492 case elfcpp::R_X86_64_GOT64
:
2493 case elfcpp::R_X86_64_GOT32
:
2494 case elfcpp::R_X86_64_GOTPCREL64
:
2495 case elfcpp::R_X86_64_GOTPCREL
:
2496 case elfcpp::R_X86_64_GOTPCRELX
:
2497 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2498 case elfcpp::R_X86_64_GOTPLT64
:
2500 // The symbol requires a GOT section.
2501 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
2503 // If the relocation symbol isn't IFUNC,
2504 // and is local, then we will convert
2505 // mov foo@GOTPCREL(%rip), %reg
2506 // to lea foo(%rip), %reg.
2507 // in Relocate::relocate.
2508 if ((r_type
== elfcpp::R_X86_64_GOTPCREL
2509 || r_type
== elfcpp::R_X86_64_GOTPCRELX
2510 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
2511 && reloc
.get_r_offset() >= 2
2514 section_size_type stype
;
2515 const unsigned char* view
= object
->section_contents(data_shndx
,
2517 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2522 // The symbol requires a GOT entry.
2523 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2525 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
2526 // lets function pointers compare correctly with shared
2527 // libraries. Otherwise we would need an IRELATIVE reloc.
2530 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
2532 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
2535 // If we are generating a shared object, we need to add a
2536 // dynamic relocation for this symbol's GOT entry.
2537 if (parameters
->options().output_is_position_independent())
2539 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2540 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2541 if (r_type
!= elfcpp::R_X86_64_GOT32
)
2543 unsigned int got_offset
=
2544 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
2545 rela_dyn
->add_local_relative(object
, r_sym
,
2546 elfcpp::R_X86_64_RELATIVE
,
2547 got
, got_offset
, 0, is_ifunc
);
2551 this->check_non_pic(object
, r_type
, NULL
);
2553 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2554 rela_dyn
->add_local(
2555 object
, r_sym
, r_type
, got
,
2556 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
2560 // For GOTPLT64, we'd normally want a PLT section, but since
2561 // we know this is a local symbol, no PLT is needed.
2565 case elfcpp::R_X86_64_COPY
:
2566 case elfcpp::R_X86_64_GLOB_DAT
:
2567 case elfcpp::R_X86_64_JUMP_SLOT
:
2568 case elfcpp::R_X86_64_RELATIVE
:
2569 case elfcpp::R_X86_64_IRELATIVE
:
2570 // These are outstanding tls relocs, which are unexpected when linking
2571 case elfcpp::R_X86_64_TPOFF64
:
2572 case elfcpp::R_X86_64_DTPMOD64
:
2573 case elfcpp::R_X86_64_TLSDESC
:
2574 gold_error(_("%s: unexpected reloc %u in object file"),
2575 object
->name().c_str(), r_type
);
2578 // These are initial tls relocs, which are expected when linking
2579 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2580 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2581 case elfcpp::R_X86_64_TLSDESC_CALL
:
2582 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2583 case elfcpp::R_X86_64_DTPOFF32
:
2584 case elfcpp::R_X86_64_DTPOFF64
:
2585 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2586 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2588 bool output_is_shared
= parameters
->options().shared();
2589 const tls::Tls_optimization optimized_type
2590 = Target_x86_64
<size
>::optimize_tls_reloc(!output_is_shared
,
2594 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
2595 if (optimized_type
== tls::TLSOPT_NONE
)
2597 // Create a pair of GOT entries for the module index and
2598 // dtv-relative offset.
2599 Output_data_got
<64, false>* got
2600 = target
->got_section(symtab
, layout
);
2601 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2602 unsigned int shndx
= lsym
.get_st_shndx();
2604 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
2606 object
->error(_("local symbol %u has bad shndx %u"),
2609 got
->add_local_pair_with_rel(object
, r_sym
,
2612 target
->rela_dyn_section(layout
),
2613 elfcpp::R_X86_64_DTPMOD64
);
2615 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2616 unsupported_reloc_local(object
, r_type
);
2619 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2620 target
->define_tls_base_symbol(symtab
, layout
);
2621 if (optimized_type
== tls::TLSOPT_NONE
)
2623 // Create reserved PLT and GOT entries for the resolver.
2624 target
->reserve_tlsdesc_entries(symtab
, layout
);
2626 // Generate a double GOT entry with an
2627 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
2628 // is resolved lazily, so the GOT entry needs to be in
2629 // an area in .got.plt, not .got. Call got_section to
2630 // make sure the section has been created.
2631 target
->got_section(symtab
, layout
);
2632 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
2633 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2634 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
2636 unsigned int got_offset
= got
->add_constant(0);
2637 got
->add_constant(0);
2638 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2640 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
2641 // We store the arguments we need in a vector, and
2642 // use the index into the vector as the parameter
2643 // to pass to the target specific routines.
2644 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
2645 void* arg
= reinterpret_cast<void*>(intarg
);
2646 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
2647 got
, got_offset
, 0);
2650 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2651 unsupported_reloc_local(object
, r_type
);
2654 case elfcpp::R_X86_64_TLSDESC_CALL
:
2657 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2658 if (optimized_type
== tls::TLSOPT_NONE
)
2660 // Create a GOT entry for the module index.
2661 target
->got_mod_index_entry(symtab
, layout
, object
);
2663 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2664 unsupported_reloc_local(object
, r_type
);
2667 case elfcpp::R_X86_64_DTPOFF32
:
2668 case elfcpp::R_X86_64_DTPOFF64
:
2671 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2672 layout
->set_has_static_tls();
2673 if (optimized_type
== tls::TLSOPT_NONE
)
2675 // Create a GOT entry for the tp-relative offset.
2676 Output_data_got
<64, false>* got
2677 = target
->got_section(symtab
, layout
);
2678 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2679 got
->add_local_with_rel(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
2680 target
->rela_dyn_section(layout
),
2681 elfcpp::R_X86_64_TPOFF64
);
2683 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2684 unsupported_reloc_local(object
, r_type
);
2687 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2688 layout
->set_has_static_tls();
2689 if (output_is_shared
)
2690 unsupported_reloc_local(object
, r_type
);
2699 case elfcpp::R_X86_64_SIZE32
:
2700 case elfcpp::R_X86_64_SIZE64
:
2702 gold_error(_("%s: unsupported reloc %u against local symbol"),
2703 object
->name().c_str(), r_type
);
2709 // Report an unsupported relocation against a global symbol.
2713 Target_x86_64
<size
>::Scan::unsupported_reloc_global(
2714 Sized_relobj_file
<size
, false>* object
,
2715 unsigned int r_type
,
2718 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2719 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2722 // Returns true if this relocation type could be that of a function pointer.
2725 Target_x86_64
<size
>::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2729 case elfcpp::R_X86_64_64
:
2730 case elfcpp::R_X86_64_32
:
2731 case elfcpp::R_X86_64_32S
:
2732 case elfcpp::R_X86_64_16
:
2733 case elfcpp::R_X86_64_8
:
2734 case elfcpp::R_X86_64_GOT64
:
2735 case elfcpp::R_X86_64_GOT32
:
2736 case elfcpp::R_X86_64_GOTPCREL64
:
2737 case elfcpp::R_X86_64_GOTPCREL
:
2738 case elfcpp::R_X86_64_GOTPCRELX
:
2739 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2740 case elfcpp::R_X86_64_GOTPLT64
:
2748 // For safe ICF, scan a relocation for a local symbol to check if it
2749 // corresponds to a function pointer being taken. In that case mark
2750 // the function whose pointer was taken as not foldable.
2754 Target_x86_64
<size
>::Scan::local_reloc_may_be_function_pointer(
2757 Target_x86_64
<size
>* ,
2758 Sized_relobj_file
<size
, false>* ,
2761 const elfcpp::Rela
<size
, false>& ,
2762 unsigned int r_type
,
2763 const elfcpp::Sym
<size
, false>&)
2765 // When building a shared library, do not fold any local symbols as it is
2766 // not possible to distinguish pointer taken versus a call by looking at
2767 // the relocation types.
2768 return (parameters
->options().shared()
2769 || possible_function_pointer_reloc(r_type
));
2772 // For safe ICF, scan a relocation for a global symbol to check if it
2773 // corresponds to a function pointer being taken. In that case mark
2774 // the function whose pointer was taken as not foldable.
2778 Target_x86_64
<size
>::Scan::global_reloc_may_be_function_pointer(
2781 Target_x86_64
<size
>* ,
2782 Sized_relobj_file
<size
, false>* ,
2785 const elfcpp::Rela
<size
, false>& ,
2786 unsigned int r_type
,
2789 // When building a shared library, do not fold symbols whose visibility
2790 // is hidden, internal or protected.
2791 return ((parameters
->options().shared()
2792 && (gsym
->visibility() == elfcpp::STV_INTERNAL
2793 || gsym
->visibility() == elfcpp::STV_PROTECTED
2794 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
2795 || possible_function_pointer_reloc(r_type
));
2798 // Scan a relocation for a global symbol.
2802 Target_x86_64
<size
>::Scan::global(Symbol_table
* symtab
,
2804 Target_x86_64
<size
>* target
,
2805 Sized_relobj_file
<size
, false>* object
,
2806 unsigned int data_shndx
,
2807 Output_section
* output_section
,
2808 const elfcpp::Rela
<size
, false>& reloc
,
2809 unsigned int r_type
,
2812 // A STT_GNU_IFUNC symbol may require a PLT entry.
2813 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2814 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2815 target
->make_plt_entry(symtab
, layout
, gsym
);
2819 case elfcpp::R_X86_64_NONE
:
2820 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2821 case elfcpp::R_X86_64_GNU_VTENTRY
:
2824 case elfcpp::R_X86_64_64
:
2825 case elfcpp::R_X86_64_32
:
2826 case elfcpp::R_X86_64_32S
:
2827 case elfcpp::R_X86_64_16
:
2828 case elfcpp::R_X86_64_8
:
2830 // Make a PLT entry if necessary.
2831 if (gsym
->needs_plt_entry())
2833 target
->make_plt_entry(symtab
, layout
, gsym
);
2834 // Since this is not a PC-relative relocation, we may be
2835 // taking the address of a function. In that case we need to
2836 // set the entry in the dynamic symbol table to the address of
2838 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2839 gsym
->set_needs_dynsym_value();
2841 // Make a dynamic relocation if necessary.
2842 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2844 if (!parameters
->options().output_is_position_independent()
2845 && gsym
->may_need_copy_reloc())
2847 target
->copy_reloc(symtab
, layout
, object
,
2848 data_shndx
, output_section
, gsym
, reloc
);
2850 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
2851 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
2852 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2853 && gsym
->can_use_relative_reloc(false)
2854 && !gsym
->is_from_dynobj()
2855 && !gsym
->is_undefined()
2856 && !gsym
->is_preemptible())
2858 // Use an IRELATIVE reloc for a locally defined
2859 // STT_GNU_IFUNC symbol. This makes a function
2860 // address in a PIE executable match the address in a
2861 // shared library that it links against.
2862 Reloc_section
* rela_dyn
=
2863 target
->rela_irelative_section(layout
);
2864 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
2865 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
2866 output_section
, object
,
2868 reloc
.get_r_offset(),
2869 reloc
.get_r_addend());
2871 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
2872 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
2873 && gsym
->can_use_relative_reloc(false))
2875 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2876 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
2877 output_section
, object
,
2879 reloc
.get_r_offset(),
2880 reloc
.get_r_addend(), false);
2884 this->check_non_pic(object
, r_type
, gsym
);
2885 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2886 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2887 data_shndx
, reloc
.get_r_offset(),
2888 reloc
.get_r_addend());
2894 case elfcpp::R_X86_64_PC64
:
2895 case elfcpp::R_X86_64_PC32
:
2896 case elfcpp::R_X86_64_PC32_BND
:
2897 case elfcpp::R_X86_64_PC16
:
2898 case elfcpp::R_X86_64_PC8
:
2900 // Make a PLT entry if necessary.
2901 if (gsym
->needs_plt_entry())
2902 target
->make_plt_entry(symtab
, layout
, gsym
);
2903 // Make a dynamic relocation if necessary.
2904 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2906 if (parameters
->options().output_is_executable()
2907 && gsym
->may_need_copy_reloc())
2909 target
->copy_reloc(symtab
, layout
, object
,
2910 data_shndx
, output_section
, gsym
, reloc
);
2914 this->check_non_pic(object
, r_type
, gsym
);
2915 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2916 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2917 data_shndx
, reloc
.get_r_offset(),
2918 reloc
.get_r_addend());
2924 case elfcpp::R_X86_64_GOT64
:
2925 case elfcpp::R_X86_64_GOT32
:
2926 case elfcpp::R_X86_64_GOTPCREL64
:
2927 case elfcpp::R_X86_64_GOTPCREL
:
2928 case elfcpp::R_X86_64_GOTPCRELX
:
2929 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2930 case elfcpp::R_X86_64_GOTPLT64
:
2932 // The symbol requires a GOT entry.
2933 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
2935 // If we convert this from
2936 // mov foo@GOTPCREL(%rip), %reg
2937 // to lea foo(%rip), %reg.
2938 // in Relocate::relocate, then there is nothing to do here.
2939 if ((r_type
== elfcpp::R_X86_64_GOTPCREL
2940 || r_type
== elfcpp::R_X86_64_GOTPCRELX
2941 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
2942 && reloc
.get_r_offset() >= 2
2943 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
))
2945 section_size_type stype
;
2946 const unsigned char* view
= object
->section_contents(data_shndx
,
2948 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2952 if (gsym
->final_value_is_known())
2954 // For a STT_GNU_IFUNC symbol we want the PLT address.
2955 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2956 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2958 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2962 // If this symbol is not fully resolved, we need to add a
2963 // dynamic relocation for it.
2964 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2966 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2968 // 1) The symbol may be defined in some other module.
2970 // 2) We are building a shared library and this is a
2971 // protected symbol; using GLOB_DAT means that the dynamic
2972 // linker can use the address of the PLT in the main
2973 // executable when appropriate so that function address
2974 // comparisons work.
2976 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2977 // code, again so that function address comparisons work.
2978 if (gsym
->is_from_dynobj()
2979 || gsym
->is_undefined()
2980 || gsym
->is_preemptible()
2981 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2982 && parameters
->options().shared())
2983 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2984 && parameters
->options().output_is_position_independent()))
2985 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
2986 elfcpp::R_X86_64_GLOB_DAT
);
2989 // For a STT_GNU_IFUNC symbol we want to write the PLT
2990 // offset into the GOT, so that function pointer
2991 // comparisons work correctly.
2993 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2994 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2997 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2998 // Tell the dynamic linker to use the PLT address
2999 // when resolving relocations.
3000 if (gsym
->is_from_dynobj()
3001 && !parameters
->options().shared())
3002 gsym
->set_needs_dynsym_value();
3006 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
3007 rela_dyn
->add_global_relative(gsym
,
3008 elfcpp::R_X86_64_RELATIVE
,
3009 got
, got_off
, 0, false);
3016 case elfcpp::R_X86_64_PLT32
:
3017 case elfcpp::R_X86_64_PLT32_BND
:
3018 // If the symbol is fully resolved, this is just a PC32 reloc.
3019 // Otherwise we need a PLT entry.
3020 if (gsym
->final_value_is_known())
3022 // If building a shared library, we can also skip the PLT entry
3023 // if the symbol is defined in the output file and is protected
3025 if (gsym
->is_defined()
3026 && !gsym
->is_from_dynobj()
3027 && !gsym
->is_preemptible())
3029 target
->make_plt_entry(symtab
, layout
, gsym
);
3032 case elfcpp::R_X86_64_GOTPC32
:
3033 case elfcpp::R_X86_64_GOTOFF64
:
3034 case elfcpp::R_X86_64_GOTPC64
:
3035 case elfcpp::R_X86_64_PLTOFF64
:
3036 // We need a GOT section.
3037 target
->got_section(symtab
, layout
);
3038 // For PLTOFF64, we also need a PLT entry (but only if the
3039 // symbol is not fully resolved).
3040 if (r_type
== elfcpp::R_X86_64_PLTOFF64
3041 && !gsym
->final_value_is_known())
3042 target
->make_plt_entry(symtab
, layout
, gsym
);
3045 case elfcpp::R_X86_64_COPY
:
3046 case elfcpp::R_X86_64_GLOB_DAT
:
3047 case elfcpp::R_X86_64_JUMP_SLOT
:
3048 case elfcpp::R_X86_64_RELATIVE
:
3049 case elfcpp::R_X86_64_IRELATIVE
:
3050 // These are outstanding tls relocs, which are unexpected when linking
3051 case elfcpp::R_X86_64_TPOFF64
:
3052 case elfcpp::R_X86_64_DTPMOD64
:
3053 case elfcpp::R_X86_64_TLSDESC
:
3054 gold_error(_("%s: unexpected reloc %u in object file"),
3055 object
->name().c_str(), r_type
);
3058 // These are initial tls relocs, which are expected for global()
3059 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3060 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3061 case elfcpp::R_X86_64_TLSDESC_CALL
:
3062 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3063 case elfcpp::R_X86_64_DTPOFF32
:
3064 case elfcpp::R_X86_64_DTPOFF64
:
3065 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3066 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3068 // For the Initial-Exec model, we can treat undef symbols as final
3069 // when building an executable.
3070 const bool is_final
= (gsym
->final_value_is_known() ||
3071 (r_type
== elfcpp::R_X86_64_GOTTPOFF
&&
3072 gsym
->is_undefined() &&
3073 parameters
->options().output_is_executable()));
3074 const tls::Tls_optimization optimized_type
3075 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
3078 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
3079 if (optimized_type
== tls::TLSOPT_NONE
)
3081 // Create a pair of GOT entries for the module index and
3082 // dtv-relative offset.
3083 Output_data_got
<64, false>* got
3084 = target
->got_section(symtab
, layout
);
3085 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
3086 target
->rela_dyn_section(layout
),
3087 elfcpp::R_X86_64_DTPMOD64
,
3088 elfcpp::R_X86_64_DTPOFF64
);
3090 else if (optimized_type
== tls::TLSOPT_TO_IE
)
3092 // Create a GOT entry for the tp-relative offset.
3093 Output_data_got
<64, false>* got
3094 = target
->got_section(symtab
, layout
);
3095 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3096 target
->rela_dyn_section(layout
),
3097 elfcpp::R_X86_64_TPOFF64
);
3099 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3100 unsupported_reloc_global(object
, r_type
, gsym
);
3103 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3104 target
->define_tls_base_symbol(symtab
, layout
);
3105 if (optimized_type
== tls::TLSOPT_NONE
)
3107 // Create reserved PLT and GOT entries for the resolver.
3108 target
->reserve_tlsdesc_entries(symtab
, layout
);
3110 // Create a double GOT entry with an R_X86_64_TLSDESC
3111 // reloc. The R_X86_64_TLSDESC reloc is resolved
3112 // lazily, so the GOT entry needs to be in an area in
3113 // .got.plt, not .got. Call got_section to make sure
3114 // the section has been created.
3115 target
->got_section(symtab
, layout
);
3116 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
3117 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
3118 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
3119 elfcpp::R_X86_64_TLSDESC
, 0);
3121 else if (optimized_type
== tls::TLSOPT_TO_IE
)
3123 // Create a GOT entry for the tp-relative offset.
3124 Output_data_got
<64, false>* got
3125 = target
->got_section(symtab
, layout
);
3126 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3127 target
->rela_dyn_section(layout
),
3128 elfcpp::R_X86_64_TPOFF64
);
3130 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3131 unsupported_reloc_global(object
, r_type
, gsym
);
3134 case elfcpp::R_X86_64_TLSDESC_CALL
:
3137 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3138 if (optimized_type
== tls::TLSOPT_NONE
)
3140 // Create a GOT entry for the module index.
3141 target
->got_mod_index_entry(symtab
, layout
, object
);
3143 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3144 unsupported_reloc_global(object
, r_type
, gsym
);
3147 case elfcpp::R_X86_64_DTPOFF32
:
3148 case elfcpp::R_X86_64_DTPOFF64
:
3151 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3152 layout
->set_has_static_tls();
3153 if (optimized_type
== tls::TLSOPT_NONE
)
3155 // Create a GOT entry for the tp-relative offset.
3156 Output_data_got
<64, false>* got
3157 = target
->got_section(symtab
, layout
);
3158 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3159 target
->rela_dyn_section(layout
),
3160 elfcpp::R_X86_64_TPOFF64
);
3162 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3163 unsupported_reloc_global(object
, r_type
, gsym
);
3166 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3167 layout
->set_has_static_tls();
3168 if (parameters
->options().shared())
3169 unsupported_reloc_global(object
, r_type
, gsym
);
3178 case elfcpp::R_X86_64_SIZE32
:
3179 case elfcpp::R_X86_64_SIZE64
:
3181 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3182 object
->name().c_str(), r_type
,
3183 gsym
->demangled_name().c_str());
3190 Target_x86_64
<size
>::gc_process_relocs(Symbol_table
* symtab
,
3192 Sized_relobj_file
<size
, false>* object
,
3193 unsigned int data_shndx
,
3194 unsigned int sh_type
,
3195 const unsigned char* prelocs
,
3197 Output_section
* output_section
,
3198 bool needs_special_offset_handling
,
3199 size_t local_symbol_count
,
3200 const unsigned char* plocal_symbols
)
3202 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
3205 if (sh_type
== elfcpp::SHT_REL
)
3210 gold::gc_process_relocs
<size
, false, Target_x86_64
<size
>, Scan
,
3220 needs_special_offset_handling
,
3225 // Scan relocations for a section.
3229 Target_x86_64
<size
>::scan_relocs(Symbol_table
* symtab
,
3231 Sized_relobj_file
<size
, false>* object
,
3232 unsigned int data_shndx
,
3233 unsigned int sh_type
,
3234 const unsigned char* prelocs
,
3236 Output_section
* output_section
,
3237 bool needs_special_offset_handling
,
3238 size_t local_symbol_count
,
3239 const unsigned char* plocal_symbols
)
3241 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
3244 if (sh_type
== elfcpp::SHT_REL
)
3246 gold_error(_("%s: unsupported REL reloc section"),
3247 object
->name().c_str());
3251 gold::scan_relocs
<size
, false, Target_x86_64
<size
>, Scan
, Classify_reloc
>(
3260 needs_special_offset_handling
,
3265 // Finalize the sections.
3269 Target_x86_64
<size
>::do_finalize_sections(
3271 const Input_objects
*,
3272 Symbol_table
* symtab
)
3274 const Reloc_section
* rel_plt
= (this->plt_
== NULL
3276 : this->plt_
->rela_plt());
3277 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
3278 this->rela_dyn_
, true, false);
3280 // Fill in some more dynamic tags.
3281 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
3284 if (this->plt_
!= NULL
3285 && this->plt_
->output_section() != NULL
3286 && this->plt_
->has_tlsdesc_entry())
3288 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
3289 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
3290 this->got_
->finalize_data_size();
3291 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
3292 this->plt_
, plt_offset
);
3293 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
3294 this->got_
, got_offset
);
3298 // Emit any relocs we saved in an attempt to avoid generating COPY
3300 if (this->copy_relocs_
.any_saved_relocs())
3301 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
3303 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3304 // the .got.plt section.
3305 Symbol
* sym
= this->global_offset_table_
;
3308 uint64_t data_size
= this->got_plt_
->current_data_size();
3309 symtab
->get_sized_symbol
<size
>(sym
)->set_symsize(data_size
);
3312 if (parameters
->doing_static_link()
3313 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
3315 // If linking statically, make sure that the __rela_iplt symbols
3316 // were defined if necessary, even if we didn't create a PLT.
3317 static const Define_symbol_in_segment syms
[] =
3320 "__rela_iplt_start", // name
3321 elfcpp::PT_LOAD
, // segment_type
3322 elfcpp::PF_W
, // segment_flags_set
3323 elfcpp::PF(0), // segment_flags_clear
3326 elfcpp::STT_NOTYPE
, // type
3327 elfcpp::STB_GLOBAL
, // binding
3328 elfcpp::STV_HIDDEN
, // visibility
3330 Symbol::SEGMENT_START
, // offset_from_base
3334 "__rela_iplt_end", // name
3335 elfcpp::PT_LOAD
, // segment_type
3336 elfcpp::PF_W
, // segment_flags_set
3337 elfcpp::PF(0), // segment_flags_clear
3340 elfcpp::STT_NOTYPE
, // type
3341 elfcpp::STB_GLOBAL
, // binding
3342 elfcpp::STV_HIDDEN
, // visibility
3344 Symbol::SEGMENT_START
, // offset_from_base
3349 symtab
->define_symbols(layout
, 2, syms
,
3350 layout
->script_options()->saw_sections_clause());
3354 // For x32, we need to handle PC-relative relocations using full 64-bit
3355 // arithmetic, so that we can detect relocation overflows properly.
3356 // This class overrides the pcrela32_check methods from the defaults in
3357 // Relocate_functions in reloc.h.
3360 class X86_64_relocate_functions
: public Relocate_functions
<size
, false>
3363 typedef Relocate_functions
<size
, false> Base
;
3365 // Do a simple PC relative relocation with the addend in the
3367 static inline typename
Base::Reloc_status
3368 pcrela32_check(unsigned char* view
,
3369 typename
elfcpp::Elf_types
<64>::Elf_Addr value
,
3370 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
3371 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
3373 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
3374 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
3375 value
= value
+ addend
- address
;
3376 elfcpp::Swap
<32, false>::writeval(wv
, value
);
3377 return (Bits
<32>::has_overflow(value
)
3378 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
3381 // Do a simple PC relative relocation with a Symbol_value with the
3382 // addend in the relocation.
3383 static inline typename
Base::Reloc_status
3384 pcrela32_check(unsigned char* view
,
3385 const Sized_relobj_file
<size
, false>* object
,
3386 const Symbol_value
<size
>* psymval
,
3387 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
3388 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
3390 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
3391 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
3392 typename
elfcpp::Elf_types
<64>::Elf_Addr value
;
3394 value
= psymval
->value(object
, addend
);
3397 // For negative addends, get the symbol value without
3398 // the addend, then add the addend using 64-bit arithmetic.
3399 value
= psymval
->value(object
, 0);
3403 elfcpp::Swap
<32, false>::writeval(wv
, value
);
3404 return (Bits
<32>::has_overflow(value
)
3405 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
3409 // Perform a relocation.
3413 Target_x86_64
<size
>::Relocate::relocate(
3414 const Relocate_info
<size
, false>* relinfo
,
3416 Target_x86_64
<size
>* target
,
3419 const unsigned char* preloc
,
3420 const Sized_symbol
<size
>* gsym
,
3421 const Symbol_value
<size
>* psymval
,
3422 unsigned char* view
,
3423 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
3424 section_size_type view_size
)
3426 typedef X86_64_relocate_functions
<size
> Reloc_funcs
;
3427 const elfcpp::Rela
<size
, false> rela(preloc
);
3428 unsigned int r_type
= elfcpp::elf_r_type
<size
>(rela
.get_r_info());
3430 if (this->skip_call_tls_get_addr_
)
3432 if ((r_type
!= elfcpp::R_X86_64_PLT32
3433 && r_type
!= elfcpp::R_X86_64_PLT32_BND
3434 && r_type
!= elfcpp::R_X86_64_PC32_BND
3435 && r_type
!= elfcpp::R_X86_64_PC32
)
3437 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
3439 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3440 _("missing expected TLS relocation"));
3444 this->skip_call_tls_get_addr_
= false;
3452 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
3454 // Pick the value to use for symbols defined in the PLT.
3455 Symbol_value
<size
> symval
;
3457 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
3459 symval
.set_output_value(target
->plt_address_for_global(gsym
));
3462 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
3464 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3465 if (object
->local_has_plt_offset(r_sym
))
3467 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
3472 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3474 // Get the GOT offset if needed.
3475 // The GOT pointer points to the end of the GOT section.
3476 // We need to subtract the size of the GOT section to get
3477 // the actual offset to use in the relocation.
3478 bool have_got_offset
= false;
3479 // Since the actual offset is always negative, we use signed int to
3480 // support 64-bit GOT relocations.
3484 case elfcpp::R_X86_64_GOT32
:
3485 case elfcpp::R_X86_64_GOT64
:
3486 case elfcpp::R_X86_64_GOTPLT64
:
3487 case elfcpp::R_X86_64_GOTPCREL64
:
3490 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
3491 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
3495 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3496 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
3497 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
3498 - target
->got_size());
3500 have_got_offset
= true;
3507 typename
Reloc_funcs::Reloc_status rstatus
= Reloc_funcs::RELOC_OK
;
3511 case elfcpp::R_X86_64_NONE
:
3512 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3513 case elfcpp::R_X86_64_GNU_VTENTRY
:
3516 case elfcpp::R_X86_64_64
:
3517 Reloc_funcs::rela64(view
, object
, psymval
, addend
);
3520 case elfcpp::R_X86_64_PC64
:
3521 Reloc_funcs::pcrela64(view
, object
, psymval
, addend
,
3525 case elfcpp::R_X86_64_32
:
3526 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
3527 Reloc_funcs::CHECK_UNSIGNED
);
3530 case elfcpp::R_X86_64_32S
:
3531 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
3532 Reloc_funcs::CHECK_SIGNED
);
3535 case elfcpp::R_X86_64_PC32
:
3536 case elfcpp::R_X86_64_PC32_BND
:
3537 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
3541 case elfcpp::R_X86_64_16
:
3542 Reloc_funcs::rela16(view
, object
, psymval
, addend
);
3545 case elfcpp::R_X86_64_PC16
:
3546 Reloc_funcs::pcrela16(view
, object
, psymval
, addend
, address
);
3549 case elfcpp::R_X86_64_8
:
3550 Reloc_funcs::rela8(view
, object
, psymval
, addend
);
3553 case elfcpp::R_X86_64_PC8
:
3554 Reloc_funcs::pcrela8(view
, object
, psymval
, addend
, address
);
3557 case elfcpp::R_X86_64_PLT32
:
3558 case elfcpp::R_X86_64_PLT32_BND
:
3559 gold_assert(gsym
== NULL
3560 || gsym
->has_plt_offset()
3561 || gsym
->final_value_is_known()
3562 || (gsym
->is_defined()
3563 && !gsym
->is_from_dynobj()
3564 && !gsym
->is_preemptible()));
3565 // Note: while this code looks the same as for R_X86_64_PC32, it
3566 // behaves differently because psymval was set to point to
3567 // the PLT entry, rather than the symbol, in Scan::global().
3568 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
3572 case elfcpp::R_X86_64_PLTOFF64
:
3575 gold_assert(gsym
->has_plt_offset()
3576 || gsym
->final_value_is_known());
3577 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
;
3578 // This is the address of GLOBAL_OFFSET_TABLE.
3579 got_address
= target
->got_plt_section()->address();
3580 Reloc_funcs::rela64(view
, object
, psymval
, addend
- got_address
);
3584 case elfcpp::R_X86_64_GOT32
:
3585 gold_assert(have_got_offset
);
3586 Reloc_funcs::rela32(view
, got_offset
, addend
);
3589 case elfcpp::R_X86_64_GOTPC32
:
3592 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3593 value
= target
->got_plt_section()->address();
3594 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
3598 case elfcpp::R_X86_64_GOT64
:
3599 case elfcpp::R_X86_64_GOTPLT64
:
3600 // R_X86_64_GOTPLT64 is obsolete and treated the the same as
3602 gold_assert(have_got_offset
);
3603 Reloc_funcs::rela64(view
, got_offset
, addend
);
3606 case elfcpp::R_X86_64_GOTPC64
:
3609 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3610 value
= target
->got_plt_section()->address();
3611 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
3615 case elfcpp::R_X86_64_GOTOFF64
:
3617 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3618 value
= (psymval
->value(object
, 0)
3619 - target
->got_plt_section()->address());
3620 Reloc_funcs::rela64(view
, value
, addend
);
3624 case elfcpp::R_X86_64_GOTPCREL
:
3625 case elfcpp::R_X86_64_GOTPCRELX
:
3626 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3629 // mov foo@GOTPCREL(%rip), %reg
3630 // to lea foo(%rip), %reg.
3632 if (rela
.get_r_offset() >= 2
3634 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
3636 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
))))
3639 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
3645 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
3646 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
3650 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3651 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
3652 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
3653 - target
->got_size());
3655 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3656 value
= target
->got_plt_section()->address() + got_offset
;
3657 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
3662 case elfcpp::R_X86_64_GOTPCREL64
:
3664 gold_assert(have_got_offset
);
3665 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
3666 value
= target
->got_plt_section()->address() + got_offset
;
3667 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
3671 case elfcpp::R_X86_64_COPY
:
3672 case elfcpp::R_X86_64_GLOB_DAT
:
3673 case elfcpp::R_X86_64_JUMP_SLOT
:
3674 case elfcpp::R_X86_64_RELATIVE
:
3675 case elfcpp::R_X86_64_IRELATIVE
:
3676 // These are outstanding tls relocs, which are unexpected when linking
3677 case elfcpp::R_X86_64_TPOFF64
:
3678 case elfcpp::R_X86_64_DTPMOD64
:
3679 case elfcpp::R_X86_64_TLSDESC
:
3680 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3681 _("unexpected reloc %u in object file"),
3685 // These are initial tls relocs, which are expected when linking
3686 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3687 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3688 case elfcpp::R_X86_64_TLSDESC_CALL
:
3689 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3690 case elfcpp::R_X86_64_DTPOFF32
:
3691 case elfcpp::R_X86_64_DTPOFF64
:
3692 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3693 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3694 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
3695 view
, address
, view_size
);
3698 case elfcpp::R_X86_64_SIZE32
:
3699 case elfcpp::R_X86_64_SIZE64
:
3701 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3702 _("unsupported reloc %u"),
3707 if (rstatus
== Reloc_funcs::RELOC_OVERFLOW
)
3711 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3712 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3713 _("relocation overflow: "
3714 "reference to local symbol %u in %s"),
3715 r_sym
, object
->name().c_str());
3717 else if (gsym
->is_defined() && gsym
->source() == Symbol::FROM_OBJECT
)
3719 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3720 _("relocation overflow: "
3721 "reference to '%s' defined in %s"),
3723 gsym
->object()->name().c_str());
3727 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3728 _("relocation overflow: reference to '%s'"),
3736 // Perform a TLS relocation.
3740 Target_x86_64
<size
>::Relocate::relocate_tls(
3741 const Relocate_info
<size
, false>* relinfo
,
3742 Target_x86_64
<size
>* target
,
3744 const elfcpp::Rela
<size
, false>& rela
,
3745 unsigned int r_type
,
3746 const Sized_symbol
<size
>* gsym
,
3747 const Symbol_value
<size
>* psymval
,
3748 unsigned char* view
,
3749 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
3750 section_size_type view_size
)
3752 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3754 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
3755 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3756 elfcpp::Shdr
<size
, false> data_shdr(relinfo
->data_shdr
);
3757 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
3759 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
3761 const bool is_final
= (gsym
== NULL
3762 ? !parameters
->options().shared()
3763 : gsym
->final_value_is_known());
3764 tls::Tls_optimization optimized_type
3765 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
3768 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3769 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3771 // If this code sequence is used in a non-executable section,
3772 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3773 // on the assumption that it's being used by itself in a debug
3774 // section. Therefore, in the unlikely event that the code
3775 // sequence appears in a non-executable section, we simply
3776 // leave it unoptimized.
3777 optimized_type
= tls::TLSOPT_NONE
;
3779 if (optimized_type
== tls::TLSOPT_TO_LE
)
3781 if (tls_segment
== NULL
)
3783 gold_assert(parameters
->errors()->error_count() > 0
3784 || issue_undefined_symbol_error(gsym
));
3787 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3788 rela
, r_type
, value
, view
,
3794 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3795 ? GOT_TYPE_TLS_OFFSET
3796 : GOT_TYPE_TLS_PAIR
);
3797 unsigned int got_offset
;
3800 gold_assert(gsym
->has_got_offset(got_type
));
3801 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3805 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3806 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3807 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3808 - target
->got_size());
3810 if (optimized_type
== tls::TLSOPT_TO_IE
)
3812 value
= target
->got_plt_section()->address() + got_offset
;
3813 this->tls_gd_to_ie(relinfo
, relnum
, rela
, r_type
,
3814 value
, view
, address
, view_size
);
3817 else if (optimized_type
== tls::TLSOPT_NONE
)
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
,
3827 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3828 _("unsupported reloc %u"), r_type
);
3831 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3832 case elfcpp::R_X86_64_TLSDESC_CALL
:
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_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3847 rela
, r_type
, value
, view
,
3853 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3854 ? GOT_TYPE_TLS_OFFSET
3855 : GOT_TYPE_TLS_DESC
);
3856 unsigned int got_offset
= 0;
3857 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
3858 && optimized_type
== tls::TLSOPT_NONE
)
3860 // We created GOT entries in the .got.tlsdesc portion of
3861 // the .got.plt section, but the offset stored in the
3862 // symbol is the offset within .got.tlsdesc.
3863 got_offset
= (target
->got_size()
3864 + target
->got_plt_section()->data_size());
3868 gold_assert(gsym
->has_got_offset(got_type
));
3869 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3873 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
3874 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3875 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3876 - target
->got_size());
3878 if (optimized_type
== tls::TLSOPT_TO_IE
)
3880 value
= target
->got_plt_section()->address() + got_offset
;
3881 this->tls_desc_gd_to_ie(relinfo
, relnum
,
3882 rela
, r_type
, value
, view
, address
,
3886 else if (optimized_type
== tls::TLSOPT_NONE
)
3888 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
3890 // Relocate the field with the offset of the pair of GOT
3892 value
= target
->got_plt_section()->address() + got_offset
;
3893 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
3899 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3900 _("unsupported reloc %u"), r_type
);
3903 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3904 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3906 // See above comment for R_X86_64_TLSGD.
3907 optimized_type
= tls::TLSOPT_NONE
;
3909 if (optimized_type
== tls::TLSOPT_TO_LE
)
3911 if (tls_segment
== NULL
)
3913 gold_assert(parameters
->errors()->error_count() > 0
3914 || issue_undefined_symbol_error(gsym
));
3917 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
3918 value
, view
, view_size
);
3921 else if (optimized_type
== tls::TLSOPT_NONE
)
3923 // Relocate the field with the offset of the GOT entry for
3924 // the module index.
3925 unsigned int got_offset
;
3926 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3927 - target
->got_size());
3928 value
= target
->got_plt_section()->address() + got_offset
;
3929 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
3933 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3934 _("unsupported reloc %u"), r_type
);
3937 case elfcpp::R_X86_64_DTPOFF32
:
3938 // This relocation type is used in debugging information.
3939 // In that case we need to not optimize the value. If the
3940 // section is not executable, then we assume we should not
3941 // optimize this reloc. See comments above for R_X86_64_TLSGD,
3942 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3944 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
3946 if (tls_segment
== NULL
)
3948 gold_assert(parameters
->errors()->error_count() > 0
3949 || issue_undefined_symbol_error(gsym
));
3952 value
-= tls_segment
->memsz();
3954 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
3957 case elfcpp::R_X86_64_DTPOFF64
:
3958 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3959 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
3961 if (tls_segment
== NULL
)
3963 gold_assert(parameters
->errors()->error_count() > 0
3964 || issue_undefined_symbol_error(gsym
));
3967 value
-= tls_segment
->memsz();
3969 Relocate_functions
<size
, false>::rela64(view
, value
, addend
);
3972 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3974 && gsym
->is_undefined()
3975 && parameters
->options().output_is_executable())
3977 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
3979 r_type
, value
, view
,
3983 else if (optimized_type
== tls::TLSOPT_TO_LE
)
3985 if (tls_segment
== NULL
)
3987 gold_assert(parameters
->errors()->error_count() > 0
3988 || issue_undefined_symbol_error(gsym
));
3991 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
3993 r_type
, value
, view
,
3997 else if (optimized_type
== tls::TLSOPT_NONE
)
3999 // Relocate the field with the offset of the GOT entry for
4000 // the tp-relative offset of the symbol.
4001 unsigned int got_offset
;
4004 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
4005 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
4006 - target
->got_size());
4010 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4011 gold_assert(object
->local_has_got_offset(r_sym
,
4012 GOT_TYPE_TLS_OFFSET
));
4013 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
4014 - target
->got_size());
4016 value
= target
->got_plt_section()->address() + got_offset
;
4017 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
4021 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4022 _("unsupported reloc type %u"),
4026 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4027 if (tls_segment
== NULL
)
4029 gold_assert(parameters
->errors()->error_count() > 0
4030 || issue_undefined_symbol_error(gsym
));
4033 value
-= tls_segment
->memsz();
4034 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
4039 // Do a relocation in which we convert a TLS General-Dynamic to an
4044 Target_x86_64
<size
>::Relocate::tls_gd_to_ie(
4045 const Relocate_info
<size
, false>* relinfo
,
4047 const elfcpp::Rela
<size
, false>& rela
,
4049 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4050 unsigned char* view
,
4051 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4052 section_size_type view_size
)
4055 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4056 // .word 0x6666; rex64; call __tls_get_addr
4057 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4059 // leaq foo@tlsgd(%rip),%rdi;
4060 // .word 0x6666; rex64; call __tls_get_addr
4061 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4063 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
4064 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4065 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
4069 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4071 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4072 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
4073 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4078 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4080 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4081 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
4082 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4086 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4087 Relocate_functions
<size
, false>::pcrela32(view
+ 8, value
, addend
- 8,
4090 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4092 this->skip_call_tls_get_addr_
= true;
4095 // Do a relocation in which we convert a TLS General-Dynamic to a
4100 Target_x86_64
<size
>::Relocate::tls_gd_to_le(
4101 const Relocate_info
<size
, false>* relinfo
,
4103 Output_segment
* tls_segment
,
4104 const elfcpp::Rela
<size
, false>& rela
,
4106 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4107 unsigned char* view
,
4108 section_size_type view_size
)
4111 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4112 // .word 0x6666; rex64; call __tls_get_addr
4113 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4115 // leaq foo@tlsgd(%rip),%rdi;
4116 // .word 0x6666; rex64; call __tls_get_addr
4117 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4119 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
4120 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4121 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
4125 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4127 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4128 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
4129 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4134 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4136 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4137 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
4139 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4143 value
-= tls_segment
->memsz();
4144 Relocate_functions
<size
, false>::rela32(view
+ 8, value
, 0);
4146 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4148 this->skip_call_tls_get_addr_
= true;
4151 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4155 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_ie(
4156 const Relocate_info
<size
, false>* relinfo
,
4158 const elfcpp::Rela
<size
, false>& rela
,
4159 unsigned int r_type
,
4160 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4161 unsigned char* view
,
4162 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4163 section_size_type view_size
)
4165 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4167 // leaq foo@tlsdesc(%rip), %rax
4168 // ==> movq foo@gottpoff(%rip), %rax
4169 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4170 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4171 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4172 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
4174 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4175 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
4179 // call *foo@tlscall(%rax)
4181 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
4182 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
4183 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4184 view
[0] == 0xff && view
[1] == 0x10);
4190 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4194 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_le(
4195 const Relocate_info
<size
, false>* relinfo
,
4197 Output_segment
* tls_segment
,
4198 const elfcpp::Rela
<size
, false>& rela
,
4199 unsigned int r_type
,
4200 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4201 unsigned char* view
,
4202 section_size_type view_size
)
4204 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4206 // leaq foo@tlsdesc(%rip), %rax
4207 // ==> movq foo@tpoff, %rax
4208 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4209 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4210 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4211 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
4214 value
-= tls_segment
->memsz();
4215 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
4219 // call *foo@tlscall(%rax)
4221 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
4222 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
4223 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4224 view
[0] == 0xff && view
[1] == 0x10);
4232 Target_x86_64
<size
>::Relocate::tls_ld_to_le(
4233 const Relocate_info
<size
, false>* relinfo
,
4236 const elfcpp::Rela
<size
, false>& rela
,
4238 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
4239 unsigned char* view
,
4240 section_size_type view_size
)
4242 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4244 // ... leq foo@dtpoff(%rax),%reg
4245 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4247 // ... leq foo@dtpoff(%rax),%reg
4248 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4250 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4251 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
4253 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4254 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
4256 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
4259 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4261 memcpy(view
- 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4263 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4265 this->skip_call_tls_get_addr_
= true;
4268 // Do a relocation in which we convert a TLS Initial-Exec to a
4273 Target_x86_64
<size
>::Relocate::tls_ie_to_le(
4274 const Relocate_info
<size
, false>* relinfo
,
4276 Output_segment
* tls_segment
,
4277 const elfcpp::Rela
<size
, false>& rela
,
4279 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4280 unsigned char* view
,
4281 section_size_type view_size
)
4283 // We need to examine the opcodes to figure out which instruction we
4286 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4287 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4289 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4290 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4292 unsigned char op1
= view
[-3];
4293 unsigned char op2
= view
[-2];
4294 unsigned char op3
= view
[-1];
4295 unsigned char reg
= op3
>> 3;
4302 else if (size
== 32 && op1
== 0x44)
4305 view
[-1] = 0xc0 | reg
;
4309 // Special handling for %rsp.
4312 else if (size
== 32 && op1
== 0x44)
4315 view
[-1] = 0xc0 | reg
;
4322 else if (size
== 32 && op1
== 0x44)
4325 view
[-1] = 0x80 | reg
| (reg
<< 3);
4328 if (tls_segment
!= NULL
)
4329 value
-= tls_segment
->memsz();
4330 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
4333 // Relocate section data.
4337 Target_x86_64
<size
>::relocate_section(
4338 const Relocate_info
<size
, false>* relinfo
,
4339 unsigned int sh_type
,
4340 const unsigned char* prelocs
,
4342 Output_section
* output_section
,
4343 bool needs_special_offset_handling
,
4344 unsigned char* view
,
4345 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4346 section_size_type view_size
,
4347 const Reloc_symbol_changes
* reloc_symbol_changes
)
4349 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4352 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4354 gold::relocate_section
<size
, false, Target_x86_64
<size
>, Relocate
,
4355 gold::Default_comdat_behavior
, Classify_reloc
>(
4361 needs_special_offset_handling
,
4365 reloc_symbol_changes
);
4368 // Apply an incremental relocation. Incremental relocations always refer
4369 // to global symbols.
4373 Target_x86_64
<size
>::apply_relocation(
4374 const Relocate_info
<size
, false>* relinfo
,
4375 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
4376 unsigned int r_type
,
4377 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
4379 unsigned char* view
,
4380 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4381 section_size_type view_size
)
4383 gold::apply_relocation
<size
, false, Target_x86_64
<size
>,
4384 typename Target_x86_64
<size
>::Relocate
>(
4396 // Scan the relocs during a relocatable link.
4400 Target_x86_64
<size
>::scan_relocatable_relocs(
4401 Symbol_table
* symtab
,
4403 Sized_relobj_file
<size
, false>* object
,
4404 unsigned int data_shndx
,
4405 unsigned int sh_type
,
4406 const unsigned char* prelocs
,
4408 Output_section
* output_section
,
4409 bool needs_special_offset_handling
,
4410 size_t local_symbol_count
,
4411 const unsigned char* plocal_symbols
,
4412 Relocatable_relocs
* rr
)
4414 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4416 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
4417 Scan_relocatable_relocs
;
4419 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4421 gold::scan_relocatable_relocs
<size
, false, Scan_relocatable_relocs
>(
4429 needs_special_offset_handling
,
4435 // Scan the relocs for --emit-relocs.
4439 Target_x86_64
<size
>::emit_relocs_scan(
4440 Symbol_table
* symtab
,
4442 Sized_relobj_file
<size
, false>* object
,
4443 unsigned int data_shndx
,
4444 unsigned int sh_type
,
4445 const unsigned char* prelocs
,
4447 Output_section
* output_section
,
4448 bool needs_special_offset_handling
,
4449 size_t local_symbol_count
,
4450 const unsigned char* plocal_syms
,
4451 Relocatable_relocs
* rr
)
4453 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4455 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
4456 Emit_relocs_strategy
;
4458 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4460 gold::scan_relocatable_relocs
<size
, false, Emit_relocs_strategy
>(
4468 needs_special_offset_handling
,
4474 // Relocate a section during a relocatable link.
4478 Target_x86_64
<size
>::relocate_relocs(
4479 const Relocate_info
<size
, false>* relinfo
,
4480 unsigned int sh_type
,
4481 const unsigned char* prelocs
,
4483 Output_section
* output_section
,
4484 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
4485 unsigned char* view
,
4486 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
4487 section_size_type view_size
,
4488 unsigned char* reloc_view
,
4489 section_size_type reloc_view_size
)
4491 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4494 gold_assert(sh_type
== elfcpp::SHT_RELA
);
4496 gold::relocate_relocs
<size
, false, Classify_reloc
>(
4501 offset_in_output_section
,
4509 // Return the value to use for a dynamic which requires special
4510 // treatment. This is how we support equality comparisons of function
4511 // pointers across shared library boundaries, as described in the
4512 // processor specific ABI supplement.
4516 Target_x86_64
<size
>::do_dynsym_value(const Symbol
* gsym
) const
4518 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
4519 return this->plt_address_for_global(gsym
);
4522 // Return a string used to fill a code section with nops to take up
4523 // the specified length.
4527 Target_x86_64
<size
>::do_code_fill(section_size_type length
) const
4531 // Build a jmpq instruction to skip over the bytes.
4532 unsigned char jmp
[5];
4534 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
4535 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
4536 + std::string(length
- 5, static_cast<char>(0x90)));
4539 // Nop sequences of various lengths.
4540 const char nop1
[1] = { '\x90' }; // nop
4541 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
4542 const char nop3
[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4543 const char nop4
[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
4545 const char nop5
[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
4547 const char nop6
[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
4548 '\x44', '\x00', '\x00' };
4549 const char nop7
[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
4550 '\x00', '\x00', '\x00',
4552 const char nop8
[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
4553 '\x00', '\x00', '\x00',
4555 const char nop9
[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
4556 '\x84', '\x00', '\x00',
4557 '\x00', '\x00', '\x00' };
4558 const char nop10
[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4559 '\x1f', '\x84', '\x00',
4560 '\x00', '\x00', '\x00',
4562 const char nop11
[11] = { '\x66', '\x66', '\x2e', // data16
4563 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4564 '\x00', '\x00', '\x00',
4566 const char nop12
[12] = { '\x66', '\x66', '\x66', // data16; data16
4567 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4568 '\x84', '\x00', '\x00',
4569 '\x00', '\x00', '\x00' };
4570 const char nop13
[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4571 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4572 '\x1f', '\x84', '\x00',
4573 '\x00', '\x00', '\x00',
4575 const char nop14
[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4576 '\x66', '\x66', '\x2e', // data16
4577 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4578 '\x00', '\x00', '\x00',
4580 const char nop15
[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4581 '\x66', '\x66', '\x66', // data16; data16
4582 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4583 '\x84', '\x00', '\x00',
4584 '\x00', '\x00', '\x00' };
4586 const char* nops
[16] = {
4588 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
4589 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
4592 return std::string(nops
[length
], length
);
4595 // Return the addend to use for a target specific relocation. The
4596 // only target specific relocation is R_X86_64_TLSDESC for a local
4597 // symbol. We want to set the addend is the offset of the local
4598 // symbol in the TLS segment.
4602 Target_x86_64
<size
>::do_reloc_addend(void* arg
, unsigned int r_type
,
4605 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
4606 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
4607 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
4608 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
4609 const Symbol_value
<size
>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
4610 gold_assert(psymval
->is_tls_symbol());
4611 // The value of a TLS symbol is the offset in the TLS segment.
4612 return psymval
->value(ti
.object
, 0);
4615 // Return the value to use for the base of a DW_EH_PE_datarel offset
4616 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
4617 // assembler can not write out the difference between two labels in
4618 // different sections, so instead of using a pc-relative value they
4619 // use an offset from the GOT.
4623 Target_x86_64
<size
>::do_ehframe_datarel_base() const
4625 gold_assert(this->global_offset_table_
!= NULL
);
4626 Symbol
* sym
= this->global_offset_table_
;
4627 Sized_symbol
<size
>* ssym
= static_cast<Sized_symbol
<size
>*>(sym
);
4628 return ssym
->value();
4631 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4632 // compiled with -fsplit-stack. The function calls non-split-stack
4633 // code. We have to change the function so that it always ensures
4634 // that it has enough stack space to run some random function.
4636 static const unsigned char cmp_insn_32
[] = { 0x64, 0x3b, 0x24, 0x25 };
4637 static const unsigned char lea_r10_insn_32
[] = { 0x44, 0x8d, 0x94, 0x24 };
4638 static const unsigned char lea_r11_insn_32
[] = { 0x44, 0x8d, 0x9c, 0x24 };
4640 static const unsigned char cmp_insn_64
[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
4641 static const unsigned char lea_r10_insn_64
[] = { 0x4c, 0x8d, 0x94, 0x24 };
4642 static const unsigned char lea_r11_insn_64
[] = { 0x4c, 0x8d, 0x9c, 0x24 };
4646 Target_x86_64
<size
>::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
4647 section_offset_type fnoffset
,
4648 section_size_type fnsize
,
4649 const unsigned char*,
4651 unsigned char* view
,
4652 section_size_type view_size
,
4654 std::string
* to
) const
4656 const char* const cmp_insn
= reinterpret_cast<const char*>
4657 (size
== 32 ? cmp_insn_32
: cmp_insn_64
);
4658 const char* const lea_r10_insn
= reinterpret_cast<const char*>
4659 (size
== 32 ? lea_r10_insn_32
: lea_r10_insn_64
);
4660 const char* const lea_r11_insn
= reinterpret_cast<const char*>
4661 (size
== 32 ? lea_r11_insn_32
: lea_r11_insn_64
);
4663 const size_t cmp_insn_len
=
4664 (size
== 32 ? sizeof(cmp_insn_32
) : sizeof(cmp_insn_64
));
4665 const size_t lea_r10_insn_len
=
4666 (size
== 32 ? sizeof(lea_r10_insn_32
) : sizeof(lea_r10_insn_64
));
4667 const size_t lea_r11_insn_len
=
4668 (size
== 32 ? sizeof(lea_r11_insn_32
) : sizeof(lea_r11_insn_64
));
4669 const size_t nop_len
= (size
== 32 ? 7 : 8);
4671 // The function starts with a comparison of the stack pointer and a
4672 // field in the TCB. This is followed by a jump.
4675 if (this->match_view(view
, view_size
, fnoffset
, cmp_insn
, cmp_insn_len
)
4676 && fnsize
> nop_len
+ 1)
4678 // We will call __morestack if the carry flag is set after this
4679 // comparison. We turn the comparison into an stc instruction
4681 view
[fnoffset
] = '\xf9';
4682 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, nop_len
);
4684 // lea NN(%rsp),%r10
4685 // lea NN(%rsp),%r11
4686 else if ((this->match_view(view
, view_size
, fnoffset
,
4687 lea_r10_insn
, lea_r10_insn_len
)
4688 || this->match_view(view
, view_size
, fnoffset
,
4689 lea_r11_insn
, lea_r11_insn_len
))
4692 // This is loading an offset from the stack pointer for a
4693 // comparison. The offset is negative, so we decrease the
4694 // offset by the amount of space we need for the stack. This
4695 // means we will avoid calling __morestack if there happens to
4696 // be plenty of space on the stack already.
4697 unsigned char* pval
= view
+ fnoffset
+ 4;
4698 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
4699 val
-= parameters
->options().split_stack_adjust_size();
4700 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
4704 if (!object
->has_no_split_stack())
4705 object
->error(_("failed to match split-stack sequence at "
4706 "section %u offset %0zx"),
4707 shndx
, static_cast<size_t>(fnoffset
));
4711 // We have to change the function so that it calls
4712 // __morestack_non_split instead of __morestack. The former will
4713 // allocate additional stack space.
4714 *from
= "__morestack";
4715 *to
= "__morestack_non_split";
4718 // The selector for x86_64 object files. Note this is never instantiated
4719 // directly. It's only used in Target_selector_x86_64_nacl, below.
4722 class Target_selector_x86_64
: public Target_selector_freebsd
4725 Target_selector_x86_64()
4726 : Target_selector_freebsd(elfcpp::EM_X86_64
, size
, false,
4728 ? "elf64-x86-64" : "elf32-x86-64"),
4730 ? "elf64-x86-64-freebsd"
4731 : "elf32-x86-64-freebsd"),
4732 (size
== 64 ? "elf_x86_64" : "elf32_x86_64"))
4736 do_instantiate_target()
4737 { return new Target_x86_64
<size
>(); }
4741 // NaCl variant. It uses different PLT contents.
4744 class Output_data_plt_x86_64_nacl
: public Output_data_plt_x86_64
<size
>
4747 Output_data_plt_x86_64_nacl(Layout
* layout
,
4748 Output_data_got
<64, false>* got
,
4749 Output_data_got_plt_x86_64
* got_plt
,
4750 Output_data_space
* got_irelative
)
4751 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
4752 got
, got_plt
, got_irelative
)
4755 Output_data_plt_x86_64_nacl(Layout
* layout
,
4756 Output_data_got
<64, false>* got
,
4757 Output_data_got_plt_x86_64
* got_plt
,
4758 Output_data_space
* got_irelative
,
4759 unsigned int plt_count
)
4760 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
4761 got
, got_plt
, got_irelative
,
4766 virtual unsigned int
4767 do_get_plt_entry_size() const
4768 { return plt_entry_size
; }
4771 do_add_eh_frame(Layout
* layout
)
4773 layout
->add_eh_frame_for_plt(this,
4774 this->plt_eh_frame_cie
,
4775 this->plt_eh_frame_cie_size
,
4777 plt_eh_frame_fde_size
);
4781 do_fill_first_plt_entry(unsigned char* pov
,
4782 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
4783 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
4785 virtual unsigned int
4786 do_fill_plt_entry(unsigned char* pov
,
4787 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4788 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4789 unsigned int got_offset
,
4790 unsigned int plt_offset
,
4791 unsigned int plt_index
);
4794 do_fill_tlsdesc_entry(unsigned char* pov
,
4795 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4796 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4797 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
4798 unsigned int tlsdesc_got_offset
,
4799 unsigned int plt_offset
);
4802 // The size of an entry in the PLT.
4803 static const int plt_entry_size
= 64;
4805 // The first entry in the PLT.
4806 static const unsigned char first_plt_entry
[plt_entry_size
];
4808 // Other entries in the PLT for an executable.
4809 static const unsigned char plt_entry
[plt_entry_size
];
4811 // The reserved TLSDESC entry in the PLT for an executable.
4812 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
4814 // The .eh_frame unwind information for the PLT.
4815 static const int plt_eh_frame_fde_size
= 32;
4816 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
4820 class Target_x86_64_nacl
: public Target_x86_64
<size
>
4823 Target_x86_64_nacl()
4824 : Target_x86_64
<size
>(&x86_64_nacl_info
)
4827 virtual Output_data_plt_x86_64
<size
>*
4828 do_make_data_plt(Layout
* layout
,
4829 Output_data_got
<64, false>* got
,
4830 Output_data_got_plt_x86_64
* got_plt
,
4831 Output_data_space
* got_irelative
)
4833 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
4837 virtual Output_data_plt_x86_64
<size
>*
4838 do_make_data_plt(Layout
* layout
,
4839 Output_data_got
<64, false>* got
,
4840 Output_data_got_plt_x86_64
* got_plt
,
4841 Output_data_space
* got_irelative
,
4842 unsigned int plt_count
)
4844 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
4850 do_code_fill(section_size_type length
) const;
4853 static const Target::Target_info x86_64_nacl_info
;
4857 const Target::Target_info Target_x86_64_nacl
<64>::x86_64_nacl_info
=
4860 false, // is_big_endian
4861 elfcpp::EM_X86_64
, // machine_code
4862 false, // has_make_symbol
4863 false, // has_resolve
4864 true, // has_code_fill
4865 true, // is_default_stack_executable
4866 true, // can_icf_inline_merge_sections
4868 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4869 0x20000, // default_text_segment_address
4870 0x10000, // abi_pagesize (overridable by -z max-page-size)
4871 0x10000, // common_pagesize (overridable by -z common-page-size)
4872 true, // isolate_execinstr
4873 0x10000000, // rosegment_gap
4874 elfcpp::SHN_UNDEF
, // small_common_shndx
4875 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
4876 0, // small_common_section_flags
4877 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
4878 NULL
, // attributes_section
4879 NULL
, // attributes_vendor
4880 "_start", // entry_symbol_name
4881 32, // hash_entry_size
4885 const Target::Target_info Target_x86_64_nacl
<32>::x86_64_nacl_info
=
4888 false, // is_big_endian
4889 elfcpp::EM_X86_64
, // machine_code
4890 false, // has_make_symbol
4891 false, // has_resolve
4892 true, // has_code_fill
4893 true, // is_default_stack_executable
4894 true, // can_icf_inline_merge_sections
4896 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4897 0x20000, // default_text_segment_address
4898 0x10000, // abi_pagesize (overridable by -z max-page-size)
4899 0x10000, // common_pagesize (overridable by -z common-page-size)
4900 true, // isolate_execinstr
4901 0x10000000, // rosegment_gap
4902 elfcpp::SHN_UNDEF
, // small_common_shndx
4903 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
4904 0, // small_common_section_flags
4905 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
4906 NULL
, // attributes_section
4907 NULL
, // attributes_vendor
4908 "_start", // entry_symbol_name
4909 32, // hash_entry_size
4912 #define NACLMASK 0xe0 // 32-byte alignment mask.
4914 // The first entry in the PLT.
4918 Output_data_plt_x86_64_nacl
<size
>::first_plt_entry
[plt_entry_size
] =
4920 0xff, 0x35, // pushq contents of memory address
4921 0, 0, 0, 0, // replaced with address of .got + 8
4922 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
4923 0, 0, 0, 0, // replaced with address of .got + 16
4924 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
4925 0x4d, 0x01, 0xfb, // add %r15, %r11
4926 0x41, 0xff, 0xe3, // jmpq *%r11
4928 // 9-byte nop sequence to pad out to the next 32-byte boundary.
4929 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4931 // 32 bytes of nop to pad out to the standard size
4932 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4933 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4934 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4935 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4936 0x66, // excess data32 prefix
4942 Output_data_plt_x86_64_nacl
<size
>::do_fill_first_plt_entry(
4944 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4945 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
4947 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4948 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4950 - (plt_address
+ 2 + 4)));
4951 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
4953 - (plt_address
+ 9 + 4)));
4956 // Subsequent entries in the PLT.
4960 Output_data_plt_x86_64_nacl
<size
>::plt_entry
[plt_entry_size
] =
4962 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
4963 0, 0, 0, 0, // replaced with address of symbol in .got
4964 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
4965 0x4d, 0x01, 0xfb, // add %r15, %r11
4966 0x41, 0xff, 0xe3, // jmpq *%r11
4968 // 15-byte nop sequence to pad out to the next 32-byte boundary.
4969 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4970 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4972 // Lazy GOT entries point here (32-byte aligned).
4973 0x68, // pushq immediate
4974 0, 0, 0, 0, // replaced with index into relocation table
4975 0xe9, // jmp relative
4976 0, 0, 0, 0, // replaced with offset to start of .plt0
4978 // 22 bytes of nop to pad out to the standard size.
4979 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4980 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4981 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
4986 Output_data_plt_x86_64_nacl
<size
>::do_fill_plt_entry(
4988 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
4989 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
4990 unsigned int got_offset
,
4991 unsigned int plt_offset
,
4992 unsigned int plt_index
)
4994 memcpy(pov
, plt_entry
, plt_entry_size
);
4995 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3,
4996 (got_address
+ got_offset
4997 - (plt_address
+ plt_offset
5000 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_index
);
5001 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 38,
5002 - (plt_offset
+ 38 + 4));
5007 // The reserved TLSDESC entry in the PLT.
5011 Output_data_plt_x86_64_nacl
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
5013 0xff, 0x35, // pushq x(%rip)
5014 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
5015 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
5016 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
5017 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
5018 0x4d, 0x01, 0xfb, // add %r15, %r11
5019 0x41, 0xff, 0xe3, // jmpq *%r11
5021 // 41 bytes of nop to pad out to the standard size.
5022 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5023 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5024 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5025 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5026 0x66, 0x66, // excess data32 prefixes
5027 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5032 Output_data_plt_x86_64_nacl
<size
>::do_fill_tlsdesc_entry(
5034 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
5035 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
5036 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
5037 unsigned int tlsdesc_got_offset
,
5038 unsigned int plt_offset
)
5040 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
5041 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
5043 - (plt_address
+ plt_offset
5045 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
5047 + tlsdesc_got_offset
5048 - (plt_address
+ plt_offset
5052 // The .eh_frame unwind information for the PLT.
5056 Output_data_plt_x86_64_nacl
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
5058 0, 0, 0, 0, // Replaced with offset to .plt.
5059 0, 0, 0, 0, // Replaced with size of .plt.
5060 0, // Augmentation size.
5061 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
5062 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
5063 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
5064 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
5065 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
5066 13, // Block length.
5067 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
5068 elfcpp::DW_OP_breg16
, 0, // Push %rip.
5069 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
5070 elfcpp::DW_OP_and
, // & (%rip & 0x3f).
5071 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
5072 elfcpp::DW_OP_ge
, // >= ((%rip & 0x3f) >= 0x25)
5073 elfcpp::DW_OP_lit3
, // Push 3.
5074 elfcpp::DW_OP_shl
, // << (((%rip & 0x3f) >= 0x25) << 3)
5075 elfcpp::DW_OP_plus
, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5076 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
5080 // Return a string used to fill a code section with nops.
5081 // For NaCl, long NOPs are only valid if they do not cross
5082 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5085 Target_x86_64_nacl
<size
>::do_code_fill(section_size_type length
) const
5087 return std::string(length
, static_cast<char>(0x90));
5090 // The selector for x86_64-nacl object files.
5093 class Target_selector_x86_64_nacl
5094 : public Target_selector_nacl
<Target_selector_x86_64
<size
>,
5095 Target_x86_64_nacl
<size
> >
5098 Target_selector_x86_64_nacl()
5099 : Target_selector_nacl
<Target_selector_x86_64
<size
>,
5100 Target_x86_64_nacl
<size
> >("x86-64",
5102 ? "elf64-x86-64-nacl"
5103 : "elf32-x86-64-nacl",
5106 : "elf32_x86_64_nacl")
5110 Target_selector_x86_64_nacl
<64> target_selector_x86_64
;
5111 Target_selector_x86_64_nacl
<32> target_selector_x32
;
5113 } // End anonymous namespace.