1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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"
50 // A class to handle the PLT data.
52 class Output_data_plt_x86_64
: public Output_section_data
55 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
57 Output_data_plt_x86_64(Layout
* layout
, Output_data_got
<64, false>* got
,
58 Output_data_space
* got_plt
,
59 Output_data_space
* got_irelative
)
60 : Output_section_data(16), tlsdesc_rel_(NULL
), irelative_rel_(NULL
),
61 got_(got
), got_plt_(got_plt
), got_irelative_(got_irelative
), count_(0),
62 irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
63 { this->init(layout
); }
65 Output_data_plt_x86_64(Layout
* layout
, Output_data_got
<64, false>* got
,
66 Output_data_space
* got_plt
,
67 Output_data_space
* got_irelative
,
68 unsigned int plt_count
)
69 : Output_section_data((plt_count
+ 1) * plt_entry_size
, 16, false),
70 tlsdesc_rel_(NULL
), irelative_rel_(NULL
), got_(got
), got_plt_(got_plt
),
71 got_irelative_(got_irelative
), count_(plt_count
), irelative_count_(0),
72 tlsdesc_got_offset_(-1U), free_list_()
76 // Initialize the free list and reserve the first entry.
77 this->free_list_
.init((plt_count
+ 1) * plt_entry_size
, false);
78 this->free_list_
.remove(0, plt_entry_size
);
81 // Initialize the PLT section.
85 // Add an entry to the PLT.
87 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
89 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
91 add_local_ifunc_entry(Symbol_table
* symtab
, Layout
*,
92 Sized_relobj_file
<64, false>* relobj
,
93 unsigned int local_sym_index
);
95 // Add the relocation for a PLT entry.
97 add_relocation(Symbol_table
*, Layout
*, Symbol
* gsym
,
98 unsigned int got_offset
);
100 // Add the reserved TLSDESC_PLT entry to the PLT.
102 reserve_tlsdesc_entry(unsigned int got_offset
)
103 { this->tlsdesc_got_offset_
= got_offset
; }
105 // Return true if a TLSDESC_PLT entry has been reserved.
107 has_tlsdesc_entry() const
108 { return this->tlsdesc_got_offset_
!= -1U; }
110 // Return the GOT offset for the reserved TLSDESC_PLT entry.
112 get_tlsdesc_got_offset() const
113 { return this->tlsdesc_got_offset_
; }
115 // Return the offset of the reserved TLSDESC_PLT entry.
117 get_tlsdesc_plt_offset() const
118 { return (this->count_
+ this->irelative_count_
+ 1) * plt_entry_size
; }
120 // Return the .rela.plt section data.
123 { return this->rel_
; }
125 // Return where the TLSDESC relocations should go.
127 rela_tlsdesc(Layout
*);
129 // Return where the IRELATIVE relocations should go in the PLT
132 rela_irelative(Symbol_table
*, Layout
*);
134 // Return whether we created a section for IRELATIVE relocations.
136 has_irelative_section() const
137 { return this->irelative_rel_
!= NULL
; }
139 // Return the number of PLT entries.
142 { return this->count_
+ this->irelative_count_
; }
144 // Return the offset of the first non-reserved PLT entry.
146 first_plt_entry_offset()
147 { return plt_entry_size
; }
149 // Return the size of a PLT entry.
152 { return plt_entry_size
; }
154 // Reserve a slot in the PLT for an existing symbol in an incremental update.
156 reserve_slot(unsigned int plt_index
)
158 this->free_list_
.remove((plt_index
+ 1) * plt_entry_size
,
159 (plt_index
+ 2) * plt_entry_size
);
162 // Return the PLT address to use for a global symbol.
164 address_for_global(const Symbol
*);
166 // Return the PLT address to use for a local symbol.
168 address_for_local(const Relobj
*, unsigned int symndx
);
172 do_adjust_output_section(Output_section
* os
);
174 // Write to a map file.
176 do_print_to_mapfile(Mapfile
* mapfile
) const
177 { mapfile
->print_output_data(this, _("** PLT")); }
180 // The size of an entry in the PLT.
181 static const int plt_entry_size
= 16;
183 // The first entry in the PLT.
184 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
185 // procedure linkage table for both programs and shared objects."
186 static const unsigned char first_plt_entry
[plt_entry_size
];
188 // Other entries in the PLT for an executable.
189 static const unsigned char plt_entry
[plt_entry_size
];
191 // The reserved TLSDESC entry in the PLT for an executable.
192 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
194 // The .eh_frame unwind information for the PLT.
195 static const int plt_eh_frame_cie_size
= 16;
196 static const int plt_eh_frame_fde_size
= 32;
197 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
198 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
200 // Set the final size.
202 set_final_data_size();
204 // Write out the PLT data.
206 do_write(Output_file
*);
208 // The reloc section.
210 // The TLSDESC relocs, if necessary. These must follow the regular
212 Reloc_section
* tlsdesc_rel_
;
213 // The IRELATIVE relocs, if necessary. These must follow the
214 // regular PLT relocations and the TLSDESC relocations.
215 Reloc_section
* irelative_rel_
;
217 Output_data_got
<64, false>* got_
;
218 // The .got.plt section.
219 Output_data_space
* got_plt_
;
220 // The part of the .got.plt section used for IRELATIVE relocs.
221 Output_data_space
* got_irelative_
;
222 // The number of PLT entries.
224 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
225 // follow the regular PLT entries.
226 unsigned int irelative_count_
;
227 // Offset of the reserved TLSDESC_GOT entry when needed.
228 unsigned int tlsdesc_got_offset_
;
229 // List of available regions within the section, for incremental
231 Free_list free_list_
;
234 // The x86_64 target class.
236 // http://www.x86-64.org/documentation/abi.pdf
237 // TLS info comes from
238 // http://people.redhat.com/drepper/tls.pdf
239 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
241 class Target_x86_64
: public Sized_target
<64, false>
244 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
245 // uses only Elf64_Rela relocation entries with explicit addends."
246 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
249 : Sized_target
<64, false>(&x86_64_info
),
250 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
251 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rela_dyn_(NULL
),
252 rela_irelative_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
),
253 dynbss_(NULL
), got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
254 tls_base_symbol_defined_(false)
257 // Hook for a new output section.
259 do_new_output_section(Output_section
*) const;
261 // Scan the relocations to look for symbol adjustments.
263 gc_process_relocs(Symbol_table
* symtab
,
265 Sized_relobj_file
<64, false>* object
,
266 unsigned int data_shndx
,
267 unsigned int sh_type
,
268 const unsigned char* prelocs
,
270 Output_section
* output_section
,
271 bool needs_special_offset_handling
,
272 size_t local_symbol_count
,
273 const unsigned char* plocal_symbols
);
275 // Scan the relocations to look for symbol adjustments.
277 scan_relocs(Symbol_table
* symtab
,
279 Sized_relobj_file
<64, false>* object
,
280 unsigned int data_shndx
,
281 unsigned int sh_type
,
282 const unsigned char* prelocs
,
284 Output_section
* output_section
,
285 bool needs_special_offset_handling
,
286 size_t local_symbol_count
,
287 const unsigned char* plocal_symbols
);
289 // Finalize the sections.
291 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
293 // Return the value to use for a dynamic which requires special
296 do_dynsym_value(const Symbol
*) const;
298 // Relocate a section.
300 relocate_section(const Relocate_info
<64, false>*,
301 unsigned int sh_type
,
302 const unsigned char* prelocs
,
304 Output_section
* output_section
,
305 bool needs_special_offset_handling
,
307 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
308 section_size_type view_size
,
309 const Reloc_symbol_changes
*);
311 // Scan the relocs during a relocatable link.
313 scan_relocatable_relocs(Symbol_table
* symtab
,
315 Sized_relobj_file
<64, false>* object
,
316 unsigned int data_shndx
,
317 unsigned int sh_type
,
318 const unsigned char* prelocs
,
320 Output_section
* output_section
,
321 bool needs_special_offset_handling
,
322 size_t local_symbol_count
,
323 const unsigned char* plocal_symbols
,
324 Relocatable_relocs
*);
326 // Relocate a section during a relocatable link.
328 relocate_for_relocatable(const Relocate_info
<64, false>*,
329 unsigned int sh_type
,
330 const unsigned char* prelocs
,
332 Output_section
* output_section
,
333 off_t offset_in_output_section
,
334 const Relocatable_relocs
*,
336 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
337 section_size_type view_size
,
338 unsigned char* reloc_view
,
339 section_size_type reloc_view_size
);
341 // Return a string used to fill a code section with nops.
343 do_code_fill(section_size_type length
) const;
345 // Return whether SYM is defined by the ABI.
347 do_is_defined_by_abi(const Symbol
* sym
) const
348 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
350 // Return the symbol index to use for a target specific relocation.
351 // The only target specific relocation is R_X86_64_TLSDESC for a
352 // local symbol, which is an absolute reloc.
354 do_reloc_symbol_index(void*, unsigned int r_type
) const
356 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
360 // Return the addend to use for a target specific relocation.
362 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
364 // Return the PLT section.
366 do_plt_address_for_global(const Symbol
* gsym
) const
367 { return this->plt_section()->address_for_global(gsym
); }
370 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
371 { return this->plt_section()->address_for_local(relobj
, symndx
); }
373 // This function should be defined in targets that can use relocation
374 // types to determine (implemented in local_reloc_may_be_function_pointer
375 // and global_reloc_may_be_function_pointer)
376 // if a function's pointer is taken. ICF uses this in safe mode to only
377 // fold those functions whose pointer is defintely not taken. For x86_64
378 // pie binaries, safe ICF cannot be done by looking at relocation types.
380 do_can_check_for_function_pointers() const
381 { return !parameters
->options().pie(); }
383 // Return the base for a DW_EH_PE_datarel encoding.
385 do_ehframe_datarel_base() const;
387 // Adjust -fsplit-stack code which calls non-split-stack code.
389 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
390 section_offset_type fnoffset
, section_size_type fnsize
,
391 unsigned char* view
, section_size_type view_size
,
392 std::string
* from
, std::string
* to
) const;
394 // Return the size of the GOT section.
398 gold_assert(this->got_
!= NULL
);
399 return this->got_
->data_size();
402 // Return the number of entries in the GOT.
404 got_entry_count() const
406 if (this->got_
== NULL
)
408 return this->got_size() / 8;
411 // Return the number of entries in the PLT.
413 plt_entry_count() const;
415 // Return the offset of the first non-reserved PLT entry.
417 first_plt_entry_offset() const;
419 // Return the size of each PLT entry.
421 plt_entry_size() const;
423 // Create the GOT section for an incremental update.
424 Output_data_got
<64, false>*
425 init_got_plt_for_update(Symbol_table
* symtab
,
427 unsigned int got_count
,
428 unsigned int plt_count
);
430 // Reserve a GOT entry for a local symbol, and regenerate any
431 // necessary dynamic relocations.
433 reserve_local_got_entry(unsigned int got_index
,
434 Sized_relobj
<64, false>* obj
,
436 unsigned int got_type
);
438 // Reserve a GOT entry for a global symbol, and regenerate any
439 // necessary dynamic relocations.
441 reserve_global_got_entry(unsigned int got_index
, Symbol
* gsym
,
442 unsigned int got_type
);
444 // Register an existing PLT entry for a global symbol.
446 register_global_plt_entry(Symbol_table
*, Layout
*, unsigned int plt_index
,
449 // Force a COPY relocation for a given symbol.
451 emit_copy_reloc(Symbol_table
*, Symbol
*, Output_section
*, off_t
);
453 // Apply an incremental relocation.
455 apply_relocation(const Relocate_info
<64, false>* relinfo
,
456 elfcpp::Elf_types
<64>::Elf_Addr r_offset
,
458 elfcpp::Elf_types
<64>::Elf_Swxword r_addend
,
461 elfcpp::Elf_types
<64>::Elf_Addr address
,
462 section_size_type view_size
);
464 // Add a new reloc argument, returning the index in the vector.
466 add_tlsdesc_info(Sized_relobj_file
<64, false>* object
, unsigned int r_sym
)
468 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
469 return this->tlsdesc_reloc_info_
.size() - 1;
473 // The class which scans relocations.
478 : issued_non_pic_error_(false)
482 get_reference_flags(unsigned int r_type
);
485 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
486 Sized_relobj_file
<64, false>* object
,
487 unsigned int data_shndx
,
488 Output_section
* output_section
,
489 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
490 const elfcpp::Sym
<64, false>& lsym
);
493 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
494 Sized_relobj_file
<64, false>* object
,
495 unsigned int data_shndx
,
496 Output_section
* output_section
,
497 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
501 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
502 Target_x86_64
* target
,
503 Sized_relobj_file
<64, false>* object
,
504 unsigned int data_shndx
,
505 Output_section
* output_section
,
506 const elfcpp::Rela
<64, false>& reloc
,
508 const elfcpp::Sym
<64, false>& lsym
);
511 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
512 Target_x86_64
* target
,
513 Sized_relobj_file
<64, false>* object
,
514 unsigned int data_shndx
,
515 Output_section
* output_section
,
516 const elfcpp::Rela
<64, false>& reloc
,
522 unsupported_reloc_local(Sized_relobj_file
<64, false>*, unsigned int r_type
);
525 unsupported_reloc_global(Sized_relobj_file
<64, false>*, unsigned int r_type
,
529 check_non_pic(Relobj
*, unsigned int r_type
, Symbol
*);
532 possible_function_pointer_reloc(unsigned int r_type
);
535 reloc_needs_plt_for_ifunc(Sized_relobj_file
<64, false>*,
536 unsigned int r_type
);
538 // Whether we have issued an error about a non-PIC compilation.
539 bool issued_non_pic_error_
;
542 // The class which implements relocation.
547 : skip_call_tls_get_addr_(false)
552 if (this->skip_call_tls_get_addr_
)
554 // FIXME: This needs to specify the location somehow.
555 gold_error(_("missing expected TLS relocation"));
559 // Do a relocation. Return false if the caller should not issue
560 // any warnings about this relocation.
562 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, Output_section
*,
563 size_t relnum
, const elfcpp::Rela
<64, false>&,
564 unsigned int r_type
, const Sized_symbol
<64>*,
565 const Symbol_value
<64>*,
566 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
570 // Do a TLS relocation.
572 relocate_tls(const Relocate_info
<64, false>*, Target_x86_64
*,
573 size_t relnum
, const elfcpp::Rela
<64, false>&,
574 unsigned int r_type
, const Sized_symbol
<64>*,
575 const Symbol_value
<64>*,
576 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
579 // Do a TLS General-Dynamic to Initial-Exec transition.
581 tls_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
582 Output_segment
* tls_segment
,
583 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
584 elfcpp::Elf_types
<64>::Elf_Addr value
,
586 elfcpp::Elf_types
<64>::Elf_Addr
,
587 section_size_type view_size
);
589 // Do a TLS General-Dynamic to Local-Exec transition.
591 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
592 Output_segment
* tls_segment
,
593 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
594 elfcpp::Elf_types
<64>::Elf_Addr value
,
596 section_size_type view_size
);
598 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
600 tls_desc_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
601 Output_segment
* tls_segment
,
602 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
603 elfcpp::Elf_types
<64>::Elf_Addr value
,
605 elfcpp::Elf_types
<64>::Elf_Addr
,
606 section_size_type view_size
);
608 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
610 tls_desc_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
611 Output_segment
* tls_segment
,
612 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
613 elfcpp::Elf_types
<64>::Elf_Addr value
,
615 section_size_type view_size
);
617 // Do a TLS Local-Dynamic to Local-Exec transition.
619 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
620 Output_segment
* tls_segment
,
621 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
622 elfcpp::Elf_types
<64>::Elf_Addr value
,
624 section_size_type view_size
);
626 // Do a TLS Initial-Exec to Local-Exec transition.
628 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
629 Output_segment
* tls_segment
,
630 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
631 elfcpp::Elf_types
<64>::Elf_Addr value
,
633 section_size_type view_size
);
635 // This is set if we should skip the next reloc, which should be a
636 // PLT32 reloc against ___tls_get_addr.
637 bool skip_call_tls_get_addr_
;
640 // A class which returns the size required for a relocation type,
641 // used while scanning relocs during a relocatable link.
642 class Relocatable_size_for_reloc
646 get_size_for_reloc(unsigned int, Relobj
*);
649 // Adjust TLS relocation type based on the options and whether this
650 // is a local symbol.
651 static tls::Tls_optimization
652 optimize_tls_reloc(bool is_final
, int r_type
);
654 // Get the GOT section, creating it if necessary.
655 Output_data_got
<64, false>*
656 got_section(Symbol_table
*, Layout
*);
658 // Get the GOT PLT section.
660 got_plt_section() const
662 gold_assert(this->got_plt_
!= NULL
);
663 return this->got_plt_
;
666 // Get the GOT section for TLSDESC entries.
667 Output_data_got
<64, false>*
668 got_tlsdesc_section() const
670 gold_assert(this->got_tlsdesc_
!= NULL
);
671 return this->got_tlsdesc_
;
674 // Create the PLT section.
676 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
678 // Create a PLT entry for a global symbol.
680 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
682 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
684 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
685 Sized_relobj_file
<64, false>* relobj
,
686 unsigned int local_sym_index
);
688 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
690 define_tls_base_symbol(Symbol_table
*, Layout
*);
692 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
694 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
696 // Create a GOT entry for the TLS module index.
698 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
699 Sized_relobj_file
<64, false>* object
);
701 // Get the PLT section.
702 Output_data_plt_x86_64
*
705 gold_assert(this->plt_
!= NULL
);
709 // Get the dynamic reloc section, creating it if necessary.
711 rela_dyn_section(Layout
*);
713 // Get the section to use for TLSDESC relocations.
715 rela_tlsdesc_section(Layout
*) const;
717 // Get the section to use for IRELATIVE relocations.
719 rela_irelative_section(Layout
*);
721 // Add a potential copy relocation.
723 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
724 Sized_relobj_file
<64, false>* object
,
725 unsigned int shndx
, Output_section
* output_section
,
726 Symbol
* sym
, const elfcpp::Rela
<64, false>& reloc
)
728 this->copy_relocs_
.copy_reloc(symtab
, layout
,
729 symtab
->get_sized_symbol
<64>(sym
),
730 object
, shndx
, output_section
,
731 reloc
, this->rela_dyn_section(layout
));
734 // Information about this specific target which we pass to the
735 // general Target structure.
736 static const Target::Target_info x86_64_info
;
738 // The types of GOT entries needed for this platform.
739 // These values are exposed to the ABI in an incremental link.
740 // Do not renumber existing values without changing the version
741 // number of the .gnu_incremental_inputs section.
744 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
745 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
746 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
747 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
750 // This type is used as the argument to the target specific
751 // relocation routines. The only target specific reloc is
752 // R_X86_64_TLSDESC against a local symbol.
755 Tlsdesc_info(Sized_relobj_file
<64, false>* a_object
, unsigned int a_r_sym
)
756 : object(a_object
), r_sym(a_r_sym
)
759 // The object in which the local symbol is defined.
760 Sized_relobj_file
<64, false>* object
;
761 // The local symbol index in the object.
766 Output_data_got
<64, false>* got_
;
768 Output_data_plt_x86_64
* plt_
;
769 // The GOT PLT section.
770 Output_data_space
* got_plt_
;
771 // The GOT section for IRELATIVE relocations.
772 Output_data_space
* got_irelative_
;
773 // The GOT section for TLSDESC relocations.
774 Output_data_got
<64, false>* got_tlsdesc_
;
775 // The _GLOBAL_OFFSET_TABLE_ symbol.
776 Symbol
* global_offset_table_
;
777 // The dynamic reloc section.
778 Reloc_section
* rela_dyn_
;
779 // The section to use for IRELATIVE relocs.
780 Reloc_section
* rela_irelative_
;
781 // Relocs saved to avoid a COPY reloc.
782 Copy_relocs
<elfcpp::SHT_RELA
, 64, false> copy_relocs_
;
783 // Space for variables copied with a COPY reloc.
784 Output_data_space
* dynbss_
;
785 // Offset of the GOT entry for the TLS module index.
786 unsigned int got_mod_index_offset_
;
787 // We handle R_X86_64_TLSDESC against a local symbol as a target
788 // specific relocation. Here we store the object and local symbol
789 // index for the relocation.
790 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
791 // True if the _TLS_MODULE_BASE_ symbol has been defined.
792 bool tls_base_symbol_defined_
;
795 const Target::Target_info
Target_x86_64::x86_64_info
=
798 false, // is_big_endian
799 elfcpp::EM_X86_64
, // machine_code
800 false, // has_make_symbol
801 false, // has_resolve
802 true, // has_code_fill
803 true, // is_default_stack_executable
804 true, // can_icf_inline_merge_sections
806 "/lib/ld64.so.1", // program interpreter
807 0x400000, // default_text_segment_address
808 0x1000, // abi_pagesize (overridable by -z max-page-size)
809 0x1000, // common_pagesize (overridable by -z common-page-size)
810 elfcpp::SHN_UNDEF
, // small_common_shndx
811 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
812 0, // small_common_section_flags
813 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
814 NULL
, // attributes_section
815 NULL
// attributes_vendor
818 // This is called when a new output section is created. This is where
819 // we handle the SHF_X86_64_LARGE.
822 Target_x86_64::do_new_output_section(Output_section
* os
) const
824 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
825 os
->set_is_large_section();
828 // Get the GOT section, creating it if necessary.
830 Output_data_got
<64, false>*
831 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
833 if (this->got_
== NULL
)
835 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
837 this->got_
= new Output_data_got
<64, false>();
839 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
841 | elfcpp::SHF_WRITE
),
842 this->got_
, ORDER_RELRO_LAST
,
845 this->got_plt_
= new Output_data_space(8, "** GOT PLT");
846 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
848 | elfcpp::SHF_WRITE
),
849 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
852 // The first three entries are reserved.
853 this->got_plt_
->set_current_data_size(3 * 8);
855 // Those bytes can go into the relro segment.
856 layout
->increase_relro(3 * 8);
858 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
859 this->global_offset_table_
=
860 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
861 Symbol_table::PREDEFINED
,
863 0, 0, elfcpp::STT_OBJECT
,
865 elfcpp::STV_HIDDEN
, 0,
868 // If there are any IRELATIVE relocations, they get GOT entries
869 // in .got.plt after the jump slot entries.
870 this->got_irelative_
= new Output_data_space(8, "** GOT IRELATIVE PLT");
871 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
873 | elfcpp::SHF_WRITE
),
874 this->got_irelative_
,
875 ORDER_NON_RELRO_FIRST
, false);
877 // If there are any TLSDESC relocations, they get GOT entries in
878 // .got.plt after the jump slot and IRELATIVE entries.
879 this->got_tlsdesc_
= new Output_data_got
<64, false>();
880 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
882 | elfcpp::SHF_WRITE
),
884 ORDER_NON_RELRO_FIRST
, false);
890 // Get the dynamic reloc section, creating it if necessary.
892 Target_x86_64::Reloc_section
*
893 Target_x86_64::rela_dyn_section(Layout
* layout
)
895 if (this->rela_dyn_
== NULL
)
897 gold_assert(layout
!= NULL
);
898 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
899 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
900 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
901 ORDER_DYNAMIC_RELOCS
, false);
903 return this->rela_dyn_
;
906 // Get the section to use for IRELATIVE relocs, creating it if
907 // necessary. These go in .rela.dyn, but only after all other dynamic
908 // relocations. They need to follow the other dynamic relocations so
909 // that they can refer to global variables initialized by those
912 Target_x86_64::Reloc_section
*
913 Target_x86_64::rela_irelative_section(Layout
* layout
)
915 if (this->rela_irelative_
== NULL
)
917 // Make sure we have already created the dynamic reloc section.
918 this->rela_dyn_section(layout
);
919 this->rela_irelative_
= new Reloc_section(false);
920 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
921 elfcpp::SHF_ALLOC
, this->rela_irelative_
,
922 ORDER_DYNAMIC_RELOCS
, false);
923 gold_assert(this->rela_dyn_
->output_section()
924 == this->rela_irelative_
->output_section());
926 return this->rela_irelative_
;
929 // Initialize the PLT section.
932 Output_data_plt_x86_64::init(Layout
* layout
)
934 this->rel_
= new Reloc_section(false);
935 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
936 elfcpp::SHF_ALLOC
, this->rel_
,
937 ORDER_DYNAMIC_PLT_RELOCS
, false);
939 // Add unwind information if requested.
940 if (parameters
->options().ld_generated_unwind_info())
941 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
942 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
946 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
948 os
->set_entsize(plt_entry_size
);
951 // Add an entry to the PLT.
954 Output_data_plt_x86_64::add_entry(Symbol_table
* symtab
, Layout
* layout
,
957 gold_assert(!gsym
->has_plt_offset());
959 unsigned int plt_index
;
961 section_offset_type got_offset
;
963 unsigned int* pcount
;
965 unsigned int reserved
;
966 Output_data_space
* got
;
967 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
968 && gsym
->can_use_relative_reloc(false))
970 pcount
= &this->irelative_count_
;
973 got
= this->got_irelative_
;
977 pcount
= &this->count_
;
980 got
= this->got_plt_
;
983 if (!this->is_data_size_valid())
985 // Note that when setting the PLT offset for a non-IRELATIVE
986 // entry we skip the initial reserved PLT entry.
987 plt_index
= *pcount
+ offset
;
988 plt_offset
= plt_index
* plt_entry_size
;
992 got_offset
= (plt_index
- offset
+ reserved
) * 8;
993 gold_assert(got_offset
== got
->current_data_size());
995 // Every PLT entry needs a GOT entry which points back to the PLT
996 // entry (this will be changed by the dynamic linker, normally
997 // lazily when the function is called).
998 got
->set_current_data_size(got_offset
+ 8);
1002 // FIXME: This is probably not correct for IRELATIVE relocs.
1004 // For incremental updates, find an available slot.
1005 plt_offset
= this->free_list_
.allocate(plt_entry_size
, plt_entry_size
, 0);
1006 if (plt_offset
== -1)
1007 gold_fallback(_("out of patch space (PLT);"
1008 " relink with --incremental-full"));
1010 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1011 // can be calculated from the PLT index, adjusting for the three
1012 // reserved entries at the beginning of the GOT.
1013 plt_index
= plt_offset
/ plt_entry_size
- 1;
1014 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1017 gsym
->set_plt_offset(plt_offset
);
1019 // Every PLT entry needs a reloc.
1020 this->add_relocation(symtab
, layout
, gsym
, got_offset
);
1022 // Note that we don't need to save the symbol. The contents of the
1023 // PLT are independent of which symbols are used. The symbols only
1024 // appear in the relocations.
1027 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1031 Output_data_plt_x86_64::add_local_ifunc_entry(
1032 Symbol_table
* symtab
,
1034 Sized_relobj_file
<64, false>* relobj
,
1035 unsigned int local_sym_index
)
1037 unsigned int plt_offset
= this->irelative_count_
* plt_entry_size
;
1038 ++this->irelative_count_
;
1040 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1042 // Every PLT entry needs a GOT entry which points back to the PLT
1044 this->got_irelative_
->set_current_data_size(got_offset
+ 8);
1046 // Every PLT entry needs a reloc.
1047 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1048 rela
->add_symbolless_local_addend(relobj
, local_sym_index
,
1049 elfcpp::R_X86_64_IRELATIVE
,
1050 this->got_irelative_
, got_offset
, 0);
1055 // Add the relocation for a PLT entry.
1058 Output_data_plt_x86_64::add_relocation(Symbol_table
* symtab
, Layout
* layout
,
1059 Symbol
* gsym
, unsigned int got_offset
)
1061 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1062 && gsym
->can_use_relative_reloc(false))
1064 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1065 rela
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
1066 this->got_irelative_
, got_offset
, 0);
1070 gsym
->set_needs_dynsym_entry();
1071 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
1076 // Return where the TLSDESC relocations should go, creating it if
1077 // necessary. These follow the JUMP_SLOT relocations.
1079 Output_data_plt_x86_64::Reloc_section
*
1080 Output_data_plt_x86_64::rela_tlsdesc(Layout
* layout
)
1082 if (this->tlsdesc_rel_
== NULL
)
1084 this->tlsdesc_rel_
= new Reloc_section(false);
1085 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1086 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
1087 ORDER_DYNAMIC_PLT_RELOCS
, false);
1088 gold_assert(this->tlsdesc_rel_
->output_section()
1089 == this->rel_
->output_section());
1091 return this->tlsdesc_rel_
;
1094 // Return where the IRELATIVE relocations should go in the PLT. These
1095 // follow the JUMP_SLOT and the TLSDESC relocations.
1097 Output_data_plt_x86_64::Reloc_section
*
1098 Output_data_plt_x86_64::rela_irelative(Symbol_table
* symtab
, Layout
* layout
)
1100 if (this->irelative_rel_
== NULL
)
1102 // Make sure we have a place for the TLSDESC relocations, in
1103 // case we see any later on.
1104 this->rela_tlsdesc(layout
);
1105 this->irelative_rel_
= new Reloc_section(false);
1106 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1107 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1108 ORDER_DYNAMIC_PLT_RELOCS
, false);
1109 gold_assert(this->irelative_rel_
->output_section()
1110 == this->rel_
->output_section());
1112 if (parameters
->doing_static_link())
1114 // A statically linked executable will only have a .rela.plt
1115 // section to hold R_X86_64_IRELATIVE relocs for
1116 // STT_GNU_IFUNC symbols. The library will use these
1117 // symbols to locate the IRELATIVE relocs at program startup
1119 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
1120 Symbol_table::PREDEFINED
,
1121 this->irelative_rel_
, 0, 0,
1122 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1123 elfcpp::STV_HIDDEN
, 0, false, true);
1124 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
1125 Symbol_table::PREDEFINED
,
1126 this->irelative_rel_
, 0, 0,
1127 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1128 elfcpp::STV_HIDDEN
, 0, true, true);
1131 return this->irelative_rel_
;
1134 // Return the PLT address to use for a global symbol.
1137 Output_data_plt_x86_64::address_for_global(const Symbol
* gsym
)
1139 uint64_t offset
= 0;
1140 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1141 && gsym
->can_use_relative_reloc(false))
1142 offset
= (this->count_
+ 1) * plt_entry_size
;
1143 return this->address() + offset
;
1146 // Return the PLT address to use for a local symbol. These are always
1147 // IRELATIVE relocs.
1150 Output_data_plt_x86_64::address_for_local(const Relobj
*, unsigned int)
1152 return this->address() + (this->count_
+ 1) * plt_entry_size
;
1155 // Set the final size.
1157 Output_data_plt_x86_64::set_final_data_size()
1159 unsigned int count
= this->count_
+ this->irelative_count_
;
1160 if (this->has_tlsdesc_entry())
1162 this->set_data_size((count
+ 1) * plt_entry_size
);
1165 // The first entry in the PLT for an executable.
1167 const unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
1169 // From AMD64 ABI Draft 0.98, page 76
1170 0xff, 0x35, // pushq contents of memory address
1171 0, 0, 0, 0, // replaced with address of .got + 8
1172 0xff, 0x25, // jmp indirect
1173 0, 0, 0, 0, // replaced with address of .got + 16
1174 0x90, 0x90, 0x90, 0x90 // noop (x4)
1177 // Subsequent entries in the PLT for an executable.
1179 const unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
1181 // From AMD64 ABI Draft 0.98, page 76
1182 0xff, 0x25, // jmpq indirect
1183 0, 0, 0, 0, // replaced with address of symbol in .got
1184 0x68, // pushq immediate
1185 0, 0, 0, 0, // replaced with offset into relocation table
1186 0xe9, // jmpq relative
1187 0, 0, 0, 0 // replaced with offset to start of .plt
1190 // The reserved TLSDESC entry in the PLT for an executable.
1192 const unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry
[plt_entry_size
] =
1194 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1195 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1196 0xff, 0x35, // pushq x(%rip)
1197 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1198 0xff, 0x25, // jmpq *y(%rip)
1199 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1204 // The .eh_frame unwind information for the PLT.
1207 Output_data_plt_x86_64::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1210 'z', // Augmentation: augmentation size included.
1211 'R', // Augmentation: FDE encoding included.
1212 '\0', // End of augmentation string.
1213 1, // Code alignment factor.
1214 0x78, // Data alignment factor.
1215 16, // Return address column.
1216 1, // Augmentation size.
1217 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1218 | elfcpp::DW_EH_PE_sdata4
),
1219 elfcpp::DW_CFA_def_cfa
, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1220 elfcpp::DW_CFA_offset
+ 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1221 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1226 Output_data_plt_x86_64::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1228 0, 0, 0, 0, // Replaced with offset to .plt.
1229 0, 0, 0, 0, // Replaced with size of .plt.
1230 0, // Augmentation size.
1231 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
1232 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1233 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
1234 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1235 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1236 11, // Block length.
1237 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
1238 elfcpp::DW_OP_breg16
, 0, // Push %rip.
1239 elfcpp::DW_OP_lit15
, // Push 0xf.
1240 elfcpp::DW_OP_and
, // & (%rip & 0xf).
1241 elfcpp::DW_OP_lit11
, // Push 0xb.
1242 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 0xb)
1243 elfcpp::DW_OP_lit3
, // Push 3.
1244 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 0xb) << 3)
1245 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1246 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1252 // Write out the PLT. This uses the hand-coded instructions above,
1253 // and adjusts them as needed. This is specified by the AMD64 ABI.
1256 Output_data_plt_x86_64::do_write(Output_file
* of
)
1258 const off_t offset
= this->offset();
1259 const section_size_type oview_size
=
1260 convert_to_section_size_type(this->data_size());
1261 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1263 const off_t got_file_offset
= this->got_plt_
->offset();
1264 gold_assert(parameters
->incremental_update()
1265 || (got_file_offset
+ this->got_plt_
->data_size()
1266 == this->got_irelative_
->offset()));
1267 const section_size_type got_size
=
1268 convert_to_section_size_type(this->got_plt_
->data_size()
1269 + this->got_irelative_
->data_size());
1270 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1273 unsigned char* pov
= oview
;
1275 // The base address of the .plt section.
1276 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
1277 // The base address of the .got section.
1278 elfcpp::Elf_types
<64>::Elf_Addr got_base
= this->got_
->address();
1279 // The base address of the PLT portion of the .got section,
1280 // which is where the GOT pointer will point, and where the
1281 // three reserved GOT entries are located.
1282 elfcpp::Elf_types
<64>::Elf_Addr got_address
= this->got_plt_
->address();
1284 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1285 // We do a jmp relative to the PC at the end of this instruction.
1286 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1288 - (plt_address
+ 6)));
1289 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
1291 - (plt_address
+ 12)));
1292 pov
+= plt_entry_size
;
1294 unsigned char* got_pov
= got_view
;
1296 memset(got_pov
, 0, 24);
1299 unsigned int plt_offset
= plt_entry_size
;
1300 unsigned int got_offset
= 24;
1301 const unsigned int count
= this->count_
+ this->irelative_count_
;
1302 for (unsigned int plt_index
= 0;
1305 pov
+= plt_entry_size
,
1307 plt_offset
+= plt_entry_size
,
1310 // Set and adjust the PLT entry itself.
1311 memcpy(pov
, plt_entry
, plt_entry_size
);
1312 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1313 (got_address
+ got_offset
1314 - (plt_address
+ plt_offset
1317 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
1318 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
1319 - (plt_offset
+ plt_entry_size
));
1321 // Set the entry in the GOT.
1322 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
1325 if (this->has_tlsdesc_entry())
1327 // Set and adjust the reserved TLSDESC PLT entry.
1328 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
1329 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1330 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1332 - (plt_address
+ plt_offset
1334 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
1336 + tlsdesc_got_offset
1337 - (plt_address
+ plt_offset
1339 pov
+= plt_entry_size
;
1342 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1343 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1345 of
->write_output_view(offset
, oview_size
, oview
);
1346 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1349 // Create the PLT section.
1352 Target_x86_64::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1354 if (this->plt_
== NULL
)
1356 // Create the GOT sections first.
1357 this->got_section(symtab
, layout
);
1359 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_
,
1361 this->got_irelative_
);
1362 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1364 | elfcpp::SHF_EXECINSTR
),
1365 this->plt_
, ORDER_PLT
, false);
1367 // Make the sh_info field of .rela.plt point to .plt.
1368 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1369 rela_plt_os
->set_info_section(this->plt_
->output_section());
1373 // Return the section for TLSDESC relocations.
1375 Target_x86_64::Reloc_section
*
1376 Target_x86_64::rela_tlsdesc_section(Layout
* layout
) const
1378 return this->plt_section()->rela_tlsdesc(layout
);
1381 // Create a PLT entry for a global symbol.
1384 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1387 if (gsym
->has_plt_offset())
1390 if (this->plt_
== NULL
)
1391 this->make_plt_section(symtab
, layout
);
1393 this->plt_
->add_entry(symtab
, layout
, gsym
);
1396 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1399 Target_x86_64::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1400 Sized_relobj_file
<64, false>* relobj
,
1401 unsigned int local_sym_index
)
1403 if (relobj
->local_has_plt_offset(local_sym_index
))
1405 if (this->plt_
== NULL
)
1406 this->make_plt_section(symtab
, layout
);
1407 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1410 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1413 // Return the number of entries in the PLT.
1416 Target_x86_64::plt_entry_count() const
1418 if (this->plt_
== NULL
)
1420 return this->plt_
->entry_count();
1423 // Return the offset of the first non-reserved PLT entry.
1426 Target_x86_64::first_plt_entry_offset() const
1428 return Output_data_plt_x86_64::first_plt_entry_offset();
1431 // Return the size of each PLT entry.
1434 Target_x86_64::plt_entry_size() const
1436 return Output_data_plt_x86_64::get_plt_entry_size();
1439 // Create the GOT and PLT sections for an incremental update.
1441 Output_data_got
<64, false>*
1442 Target_x86_64::init_got_plt_for_update(Symbol_table
* symtab
,
1444 unsigned int got_count
,
1445 unsigned int plt_count
)
1447 gold_assert(this->got_
== NULL
);
1449 this->got_
= new Output_data_got
<64, false>(got_count
* 8);
1450 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1452 | elfcpp::SHF_WRITE
),
1453 this->got_
, ORDER_RELRO_LAST
,
1456 // Add the three reserved entries.
1457 this->got_plt_
= new Output_data_space((plt_count
+ 3) * 8, 8, "** GOT PLT");
1458 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1460 | elfcpp::SHF_WRITE
),
1461 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
1464 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1465 this->global_offset_table_
=
1466 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1467 Symbol_table::PREDEFINED
,
1469 0, 0, elfcpp::STT_OBJECT
,
1471 elfcpp::STV_HIDDEN
, 0,
1474 // If there are any TLSDESC relocations, they get GOT entries in
1475 // .got.plt after the jump slot entries.
1476 // FIXME: Get the count for TLSDESC entries.
1477 this->got_tlsdesc_
= new Output_data_got
<64, false>(0);
1478 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1479 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
1481 ORDER_NON_RELRO_FIRST
, false);
1483 // If there are any IRELATIVE relocations, they get GOT entries in
1484 // .got.plt after the jump slot and TLSDESC entries.
1485 this->got_irelative_
= new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1486 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1487 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
1488 this->got_irelative_
,
1489 ORDER_NON_RELRO_FIRST
, false);
1491 // Create the PLT section.
1492 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_
, this->got_plt_
,
1493 this->got_irelative_
, plt_count
);
1494 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1495 elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
,
1496 this->plt_
, ORDER_PLT
, false);
1498 // Make the sh_info field of .rela.plt point to .plt.
1499 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1500 rela_plt_os
->set_info_section(this->plt_
->output_section());
1502 // Create the rela_dyn section.
1503 this->rela_dyn_section(layout
);
1508 // Reserve a GOT entry for a local symbol, and regenerate any
1509 // necessary dynamic relocations.
1512 Target_x86_64::reserve_local_got_entry(
1513 unsigned int got_index
,
1514 Sized_relobj
<64, false>* obj
,
1516 unsigned int got_type
)
1518 unsigned int got_offset
= got_index
* 8;
1519 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
1521 this->got_
->reserve_local(got_index
, obj
, r_sym
, got_type
);
1524 case GOT_TYPE_STANDARD
:
1525 if (parameters
->options().output_is_position_independent())
1526 rela_dyn
->add_local_relative(obj
, r_sym
, elfcpp::R_X86_64_RELATIVE
,
1527 this->got_
, got_offset
, 0);
1529 case GOT_TYPE_TLS_OFFSET
:
1530 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_TPOFF64
,
1531 this->got_
, got_offset
, 0);
1533 case GOT_TYPE_TLS_PAIR
:
1534 this->got_
->reserve_slot(got_index
+ 1);
1535 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_DTPMOD64
,
1536 this->got_
, got_offset
, 0);
1538 case GOT_TYPE_TLS_DESC
:
1539 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1540 // this->got_->reserve_slot(got_index + 1);
1541 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1542 // this->got_, got_offset, 0);
1549 // Reserve a GOT entry for a global symbol, and regenerate any
1550 // necessary dynamic relocations.
1553 Target_x86_64::reserve_global_got_entry(unsigned int got_index
, Symbol
* gsym
,
1554 unsigned int got_type
)
1556 unsigned int got_offset
= got_index
* 8;
1557 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
1559 this->got_
->reserve_global(got_index
, gsym
, got_type
);
1562 case GOT_TYPE_STANDARD
:
1563 if (!gsym
->final_value_is_known())
1565 if (gsym
->is_from_dynobj()
1566 || gsym
->is_undefined()
1567 || gsym
->is_preemptible()
1568 || gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1569 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
,
1570 this->got_
, got_offset
, 0);
1572 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1573 this->got_
, got_offset
, 0);
1576 case GOT_TYPE_TLS_OFFSET
:
1577 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TPOFF64
,
1578 this->got_
, got_offset
, 0);
1580 case GOT_TYPE_TLS_PAIR
:
1581 this->got_
->reserve_slot(got_index
+ 1);
1582 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPMOD64
,
1583 this->got_
, got_offset
, 0);
1584 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPOFF64
,
1585 this->got_
, got_offset
+ 8, 0);
1587 case GOT_TYPE_TLS_DESC
:
1588 this->got_
->reserve_slot(got_index
+ 1);
1589 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TLSDESC
,
1590 this->got_
, got_offset
, 0);
1597 // Register an existing PLT entry for a global symbol.
1600 Target_x86_64::register_global_plt_entry(Symbol_table
* symtab
,
1602 unsigned int plt_index
,
1605 gold_assert(this->plt_
!= NULL
);
1606 gold_assert(!gsym
->has_plt_offset());
1608 this->plt_
->reserve_slot(plt_index
);
1610 gsym
->set_plt_offset((plt_index
+ 1) * this->plt_entry_size());
1612 unsigned int got_offset
= (plt_index
+ 3) * 8;
1613 this->plt_
->add_relocation(symtab
, layout
, gsym
, got_offset
);
1616 // Force a COPY relocation for a given symbol.
1619 Target_x86_64::emit_copy_reloc(
1620 Symbol_table
* symtab
, Symbol
* sym
, Output_section
* os
, off_t offset
)
1622 this->copy_relocs_
.emit_copy_reloc(symtab
,
1623 symtab
->get_sized_symbol
<64>(sym
),
1626 this->rela_dyn_section(NULL
));
1629 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1632 Target_x86_64::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1634 if (this->tls_base_symbol_defined_
)
1637 Output_segment
* tls_segment
= layout
->tls_segment();
1638 if (tls_segment
!= NULL
)
1640 bool is_exec
= parameters
->options().output_is_executable();
1641 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1642 Symbol_table::PREDEFINED
,
1646 elfcpp::STV_HIDDEN
, 0,
1648 ? Symbol::SEGMENT_END
1649 : Symbol::SEGMENT_START
),
1652 this->tls_base_symbol_defined_
= true;
1655 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1658 Target_x86_64::reserve_tlsdesc_entries(Symbol_table
* symtab
,
1661 if (this->plt_
== NULL
)
1662 this->make_plt_section(symtab
, layout
);
1664 if (!this->plt_
->has_tlsdesc_entry())
1666 // Allocate the TLSDESC_GOT entry.
1667 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
1668 unsigned int got_offset
= got
->add_constant(0);
1670 // Allocate the TLSDESC_PLT entry.
1671 this->plt_
->reserve_tlsdesc_entry(got_offset
);
1675 // Create a GOT entry for the TLS module index.
1678 Target_x86_64::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1679 Sized_relobj_file
<64, false>* object
)
1681 if (this->got_mod_index_offset_
== -1U)
1683 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1684 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1685 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
1686 unsigned int got_offset
= got
->add_constant(0);
1687 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
1689 got
->add_constant(0);
1690 this->got_mod_index_offset_
= got_offset
;
1692 return this->got_mod_index_offset_
;
1695 // Optimize the TLS relocation type based on what we know about the
1696 // symbol. IS_FINAL is true if the final address of this symbol is
1697 // known at link time.
1699 tls::Tls_optimization
1700 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
1702 // If we are generating a shared library, then we can't do anything
1704 if (parameters
->options().shared())
1705 return tls::TLSOPT_NONE
;
1709 case elfcpp::R_X86_64_TLSGD
:
1710 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1711 case elfcpp::R_X86_64_TLSDESC_CALL
:
1712 // These are General-Dynamic which permits fully general TLS
1713 // access. Since we know that we are generating an executable,
1714 // we can convert this to Initial-Exec. If we also know that
1715 // this is a local symbol, we can further switch to Local-Exec.
1717 return tls::TLSOPT_TO_LE
;
1718 return tls::TLSOPT_TO_IE
;
1720 case elfcpp::R_X86_64_TLSLD
:
1721 // This is Local-Dynamic, which refers to a local symbol in the
1722 // dynamic TLS block. Since we know that we generating an
1723 // executable, we can switch to Local-Exec.
1724 return tls::TLSOPT_TO_LE
;
1726 case elfcpp::R_X86_64_DTPOFF32
:
1727 case elfcpp::R_X86_64_DTPOFF64
:
1728 // Another Local-Dynamic reloc.
1729 return tls::TLSOPT_TO_LE
;
1731 case elfcpp::R_X86_64_GOTTPOFF
:
1732 // These are Initial-Exec relocs which get the thread offset
1733 // from the GOT. If we know that we are linking against the
1734 // local symbol, we can switch to Local-Exec, which links the
1735 // thread offset into the instruction.
1737 return tls::TLSOPT_TO_LE
;
1738 return tls::TLSOPT_NONE
;
1740 case elfcpp::R_X86_64_TPOFF32
:
1741 // When we already have Local-Exec, there is nothing further we
1743 return tls::TLSOPT_NONE
;
1750 // Get the Reference_flags for a particular relocation.
1753 Target_x86_64::Scan::get_reference_flags(unsigned int r_type
)
1757 case elfcpp::R_X86_64_NONE
:
1758 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1759 case elfcpp::R_X86_64_GNU_VTENTRY
:
1760 case elfcpp::R_X86_64_GOTPC32
:
1761 case elfcpp::R_X86_64_GOTPC64
:
1762 // No symbol reference.
1765 case elfcpp::R_X86_64_64
:
1766 case elfcpp::R_X86_64_32
:
1767 case elfcpp::R_X86_64_32S
:
1768 case elfcpp::R_X86_64_16
:
1769 case elfcpp::R_X86_64_8
:
1770 return Symbol::ABSOLUTE_REF
;
1772 case elfcpp::R_X86_64_PC64
:
1773 case elfcpp::R_X86_64_PC32
:
1774 case elfcpp::R_X86_64_PC16
:
1775 case elfcpp::R_X86_64_PC8
:
1776 case elfcpp::R_X86_64_GOTOFF64
:
1777 return Symbol::RELATIVE_REF
;
1779 case elfcpp::R_X86_64_PLT32
:
1780 case elfcpp::R_X86_64_PLTOFF64
:
1781 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1783 case elfcpp::R_X86_64_GOT64
:
1784 case elfcpp::R_X86_64_GOT32
:
1785 case elfcpp::R_X86_64_GOTPCREL64
:
1786 case elfcpp::R_X86_64_GOTPCREL
:
1787 case elfcpp::R_X86_64_GOTPLT64
:
1789 return Symbol::ABSOLUTE_REF
;
1791 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1792 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1793 case elfcpp::R_X86_64_TLSDESC_CALL
:
1794 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1795 case elfcpp::R_X86_64_DTPOFF32
:
1796 case elfcpp::R_X86_64_DTPOFF64
:
1797 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1798 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1799 return Symbol::TLS_REF
;
1801 case elfcpp::R_X86_64_COPY
:
1802 case elfcpp::R_X86_64_GLOB_DAT
:
1803 case elfcpp::R_X86_64_JUMP_SLOT
:
1804 case elfcpp::R_X86_64_RELATIVE
:
1805 case elfcpp::R_X86_64_IRELATIVE
:
1806 case elfcpp::R_X86_64_TPOFF64
:
1807 case elfcpp::R_X86_64_DTPMOD64
:
1808 case elfcpp::R_X86_64_TLSDESC
:
1809 case elfcpp::R_X86_64_SIZE32
:
1810 case elfcpp::R_X86_64_SIZE64
:
1812 // Not expected. We will give an error later.
1817 // Report an unsupported relocation against a local symbol.
1820 Target_x86_64::Scan::unsupported_reloc_local(
1821 Sized_relobj_file
<64, false>* object
,
1822 unsigned int r_type
)
1824 gold_error(_("%s: unsupported reloc %u against local symbol"),
1825 object
->name().c_str(), r_type
);
1828 // We are about to emit a dynamic relocation of type R_TYPE. If the
1829 // dynamic linker does not support it, issue an error. The GNU linker
1830 // only issues a non-PIC error for an allocated read-only section.
1831 // Here we know the section is allocated, but we don't know that it is
1832 // read-only. But we check for all the relocation types which the
1833 // glibc dynamic linker supports, so it seems appropriate to issue an
1834 // error even if the section is not read-only. If GSYM is not NULL,
1835 // it is the symbol the relocation is against; if it is NULL, the
1836 // relocation is against a local symbol.
1839 Target_x86_64::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
,
1844 // These are the relocation types supported by glibc for x86_64
1845 // which should always work.
1846 case elfcpp::R_X86_64_RELATIVE
:
1847 case elfcpp::R_X86_64_IRELATIVE
:
1848 case elfcpp::R_X86_64_GLOB_DAT
:
1849 case elfcpp::R_X86_64_JUMP_SLOT
:
1850 case elfcpp::R_X86_64_DTPMOD64
:
1851 case elfcpp::R_X86_64_DTPOFF64
:
1852 case elfcpp::R_X86_64_TPOFF64
:
1853 case elfcpp::R_X86_64_64
:
1854 case elfcpp::R_X86_64_COPY
:
1857 // glibc supports these reloc types, but they can overflow.
1858 case elfcpp::R_X86_64_PC32
:
1859 // A PC relative reference is OK against a local symbol or if
1860 // the symbol is defined locally.
1862 || (!gsym
->is_from_dynobj()
1863 && !gsym
->is_undefined()
1864 && !gsym
->is_preemptible()))
1867 case elfcpp::R_X86_64_32
:
1868 if (this->issued_non_pic_error_
)
1870 gold_assert(parameters
->options().output_is_position_independent());
1872 object
->error(_("requires dynamic R_X86_64_32 reloc which may "
1873 "overflow at runtime; recompile with -fPIC"));
1875 object
->error(_("requires dynamic %s reloc against '%s' which may "
1876 "overflow at runtime; recompile with -fPIC"),
1877 (r_type
== elfcpp::R_X86_64_32
1881 this->issued_non_pic_error_
= true;
1885 // This prevents us from issuing more than one error per reloc
1886 // section. But we can still wind up issuing more than one
1887 // error per object file.
1888 if (this->issued_non_pic_error_
)
1890 gold_assert(parameters
->options().output_is_position_independent());
1891 object
->error(_("requires unsupported dynamic reloc %u; "
1892 "recompile with -fPIC"),
1894 this->issued_non_pic_error_
= true;
1897 case elfcpp::R_X86_64_NONE
:
1902 // Return whether we need to make a PLT entry for a relocation of the
1903 // given type against a STT_GNU_IFUNC symbol.
1906 Target_x86_64::Scan::reloc_needs_plt_for_ifunc(
1907 Sized_relobj_file
<64, false>* object
,
1908 unsigned int r_type
)
1910 int flags
= Scan::get_reference_flags(r_type
);
1911 if (flags
& Symbol::TLS_REF
)
1912 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1913 object
->name().c_str(), r_type
);
1917 // Scan a relocation for a local symbol.
1920 Target_x86_64::Scan::local(Symbol_table
* symtab
,
1922 Target_x86_64
* target
,
1923 Sized_relobj_file
<64, false>* object
,
1924 unsigned int data_shndx
,
1925 Output_section
* output_section
,
1926 const elfcpp::Rela
<64, false>& reloc
,
1927 unsigned int r_type
,
1928 const elfcpp::Sym
<64, false>& lsym
)
1930 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1931 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1932 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1934 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1935 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1940 case elfcpp::R_X86_64_NONE
:
1941 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1942 case elfcpp::R_X86_64_GNU_VTENTRY
:
1945 case elfcpp::R_X86_64_64
:
1946 // If building a shared library (or a position-independent
1947 // executable), we need to create a dynamic relocation for this
1948 // location. The relocation applied at link time will apply the
1949 // link-time value, so we flag the location with an
1950 // R_X86_64_RELATIVE relocation so the dynamic loader can
1951 // relocate it easily.
1952 if (parameters
->options().output_is_position_independent())
1954 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1955 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1956 rela_dyn
->add_local_relative(object
, r_sym
,
1957 elfcpp::R_X86_64_RELATIVE
,
1958 output_section
, data_shndx
,
1959 reloc
.get_r_offset(),
1960 reloc
.get_r_addend());
1964 case elfcpp::R_X86_64_32
:
1965 case elfcpp::R_X86_64_32S
:
1966 case elfcpp::R_X86_64_16
:
1967 case elfcpp::R_X86_64_8
:
1968 // If building a shared library (or a position-independent
1969 // executable), we need to create a dynamic relocation for this
1970 // location. We can't use an R_X86_64_RELATIVE relocation
1971 // because that is always a 64-bit relocation.
1972 if (parameters
->options().output_is_position_independent())
1974 this->check_non_pic(object
, r_type
, NULL
);
1976 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1977 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1978 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1979 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1980 data_shndx
, reloc
.get_r_offset(),
1981 reloc
.get_r_addend());
1984 gold_assert(lsym
.get_st_value() == 0);
1985 unsigned int shndx
= lsym
.get_st_shndx();
1987 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1990 object
->error(_("section symbol %u has bad shndx %u"),
1993 rela_dyn
->add_local_section(object
, shndx
,
1994 r_type
, output_section
,
1995 data_shndx
, reloc
.get_r_offset(),
1996 reloc
.get_r_addend());
2001 case elfcpp::R_X86_64_PC64
:
2002 case elfcpp::R_X86_64_PC32
:
2003 case elfcpp::R_X86_64_PC16
:
2004 case elfcpp::R_X86_64_PC8
:
2007 case elfcpp::R_X86_64_PLT32
:
2008 // Since we know this is a local symbol, we can handle this as a
2012 case elfcpp::R_X86_64_GOTPC32
:
2013 case elfcpp::R_X86_64_GOTOFF64
:
2014 case elfcpp::R_X86_64_GOTPC64
:
2015 case elfcpp::R_X86_64_PLTOFF64
:
2016 // We need a GOT section.
2017 target
->got_section(symtab
, layout
);
2018 // For PLTOFF64, we'd normally want a PLT section, but since we
2019 // know this is a local symbol, no PLT is needed.
2022 case elfcpp::R_X86_64_GOT64
:
2023 case elfcpp::R_X86_64_GOT32
:
2024 case elfcpp::R_X86_64_GOTPCREL64
:
2025 case elfcpp::R_X86_64_GOTPCREL
:
2026 case elfcpp::R_X86_64_GOTPLT64
:
2028 // The symbol requires a GOT entry.
2029 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
2030 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
2032 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
2033 // lets function pointers compare correctly with shared
2034 // libraries. Otherwise we would need an IRELATIVE reloc.
2036 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
2037 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
2039 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
2042 // If we are generating a shared object, we need to add a
2043 // dynamic relocation for this symbol's GOT entry.
2044 if (parameters
->options().output_is_position_independent())
2046 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2047 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2048 if (r_type
!= elfcpp::R_X86_64_GOT32
)
2050 unsigned int got_offset
=
2051 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
2052 rela_dyn
->add_local_relative(object
, r_sym
,
2053 elfcpp::R_X86_64_RELATIVE
,
2054 got
, got_offset
, 0);
2058 this->check_non_pic(object
, r_type
, NULL
);
2060 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2061 rela_dyn
->add_local(
2062 object
, r_sym
, r_type
, got
,
2063 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
2067 // For GOTPLT64, we'd normally want a PLT section, but since
2068 // we know this is a local symbol, no PLT is needed.
2072 case elfcpp::R_X86_64_COPY
:
2073 case elfcpp::R_X86_64_GLOB_DAT
:
2074 case elfcpp::R_X86_64_JUMP_SLOT
:
2075 case elfcpp::R_X86_64_RELATIVE
:
2076 case elfcpp::R_X86_64_IRELATIVE
:
2077 // These are outstanding tls relocs, which are unexpected when linking
2078 case elfcpp::R_X86_64_TPOFF64
:
2079 case elfcpp::R_X86_64_DTPMOD64
:
2080 case elfcpp::R_X86_64_TLSDESC
:
2081 gold_error(_("%s: unexpected reloc %u in object file"),
2082 object
->name().c_str(), r_type
);
2085 // These are initial tls relocs, which are expected when linking
2086 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2087 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2088 case elfcpp::R_X86_64_TLSDESC_CALL
:
2089 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2090 case elfcpp::R_X86_64_DTPOFF32
:
2091 case elfcpp::R_X86_64_DTPOFF64
:
2092 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2093 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2095 bool output_is_shared
= parameters
->options().shared();
2096 const tls::Tls_optimization optimized_type
2097 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
2100 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
2101 if (optimized_type
== tls::TLSOPT_NONE
)
2103 // Create a pair of GOT entries for the module index and
2104 // dtv-relative offset.
2105 Output_data_got
<64, false>* got
2106 = target
->got_section(symtab
, layout
);
2107 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
2108 unsigned int shndx
= lsym
.get_st_shndx();
2110 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
2112 object
->error(_("local symbol %u has bad shndx %u"),
2115 got
->add_local_pair_with_rela(object
, r_sym
,
2118 target
->rela_dyn_section(layout
),
2119 elfcpp::R_X86_64_DTPMOD64
, 0);
2121 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2122 unsupported_reloc_local(object
, r_type
);
2125 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2126 target
->define_tls_base_symbol(symtab
, layout
);
2127 if (optimized_type
== tls::TLSOPT_NONE
)
2129 // Create reserved PLT and GOT entries for the resolver.
2130 target
->reserve_tlsdesc_entries(symtab
, layout
);
2132 // Generate a double GOT entry with an
2133 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
2134 // is resolved lazily, so the GOT entry needs to be in
2135 // an area in .got.plt, not .got. Call got_section to
2136 // make sure the section has been created.
2137 target
->got_section(symtab
, layout
);
2138 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
2139 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
2140 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
2142 unsigned int got_offset
= got
->add_constant(0);
2143 got
->add_constant(0);
2144 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2146 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
2147 // We store the arguments we need in a vector, and
2148 // use the index into the vector as the parameter
2149 // to pass to the target specific routines.
2150 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
2151 void* arg
= reinterpret_cast<void*>(intarg
);
2152 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
2153 got
, got_offset
, 0);
2156 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2157 unsupported_reloc_local(object
, r_type
);
2160 case elfcpp::R_X86_64_TLSDESC_CALL
:
2163 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2164 if (optimized_type
== tls::TLSOPT_NONE
)
2166 // Create a GOT entry for the module index.
2167 target
->got_mod_index_entry(symtab
, layout
, object
);
2169 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2170 unsupported_reloc_local(object
, r_type
);
2173 case elfcpp::R_X86_64_DTPOFF32
:
2174 case elfcpp::R_X86_64_DTPOFF64
:
2177 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2178 layout
->set_has_static_tls();
2179 if (optimized_type
== tls::TLSOPT_NONE
)
2181 // Create a GOT entry for the tp-relative offset.
2182 Output_data_got
<64, false>* got
2183 = target
->got_section(symtab
, layout
);
2184 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
2185 got
->add_local_with_rela(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
2186 target
->rela_dyn_section(layout
),
2187 elfcpp::R_X86_64_TPOFF64
);
2189 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2190 unsupported_reloc_local(object
, r_type
);
2193 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2194 layout
->set_has_static_tls();
2195 if (output_is_shared
)
2196 unsupported_reloc_local(object
, r_type
);
2205 case elfcpp::R_X86_64_SIZE32
:
2206 case elfcpp::R_X86_64_SIZE64
:
2208 gold_error(_("%s: unsupported reloc %u against local symbol"),
2209 object
->name().c_str(), r_type
);
2215 // Report an unsupported relocation against a global symbol.
2218 Target_x86_64::Scan::unsupported_reloc_global(
2219 Sized_relobj_file
<64, false>* object
,
2220 unsigned int r_type
,
2223 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2224 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2227 // Returns true if this relocation type could be that of a function pointer.
2229 Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2233 case elfcpp::R_X86_64_64
:
2234 case elfcpp::R_X86_64_32
:
2235 case elfcpp::R_X86_64_32S
:
2236 case elfcpp::R_X86_64_16
:
2237 case elfcpp::R_X86_64_8
:
2238 case elfcpp::R_X86_64_GOT64
:
2239 case elfcpp::R_X86_64_GOT32
:
2240 case elfcpp::R_X86_64_GOTPCREL64
:
2241 case elfcpp::R_X86_64_GOTPCREL
:
2242 case elfcpp::R_X86_64_GOTPLT64
:
2250 // For safe ICF, scan a relocation for a local symbol to check if it
2251 // corresponds to a function pointer being taken. In that case mark
2252 // the function whose pointer was taken as not foldable.
2255 Target_x86_64::Scan::local_reloc_may_be_function_pointer(
2259 Sized_relobj_file
<64, false>* ,
2262 const elfcpp::Rela
<64, false>& ,
2263 unsigned int r_type
,
2264 const elfcpp::Sym
<64, false>&)
2266 // When building a shared library, do not fold any local symbols as it is
2267 // not possible to distinguish pointer taken versus a call by looking at
2268 // the relocation types.
2269 return (parameters
->options().shared()
2270 || possible_function_pointer_reloc(r_type
));
2273 // For safe ICF, scan a relocation for a global symbol to check if it
2274 // corresponds to a function pointer being taken. In that case mark
2275 // the function whose pointer was taken as not foldable.
2278 Target_x86_64::Scan::global_reloc_may_be_function_pointer(
2282 Sized_relobj_file
<64, false>* ,
2285 const elfcpp::Rela
<64, false>& ,
2286 unsigned int r_type
,
2289 // When building a shared library, do not fold symbols whose visibility
2290 // is hidden, internal or protected.
2291 return ((parameters
->options().shared()
2292 && (gsym
->visibility() == elfcpp::STV_INTERNAL
2293 || gsym
->visibility() == elfcpp::STV_PROTECTED
2294 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
2295 || possible_function_pointer_reloc(r_type
));
2298 // Scan a relocation for a global symbol.
2301 Target_x86_64::Scan::global(Symbol_table
* symtab
,
2303 Target_x86_64
* target
,
2304 Sized_relobj_file
<64, false>* object
,
2305 unsigned int data_shndx
,
2306 Output_section
* output_section
,
2307 const elfcpp::Rela
<64, false>& reloc
,
2308 unsigned int r_type
,
2311 // A STT_GNU_IFUNC symbol may require a PLT entry.
2312 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2313 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2314 target
->make_plt_entry(symtab
, layout
, gsym
);
2318 case elfcpp::R_X86_64_NONE
:
2319 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2320 case elfcpp::R_X86_64_GNU_VTENTRY
:
2323 case elfcpp::R_X86_64_64
:
2324 case elfcpp::R_X86_64_32
:
2325 case elfcpp::R_X86_64_32S
:
2326 case elfcpp::R_X86_64_16
:
2327 case elfcpp::R_X86_64_8
:
2329 // Make a PLT entry if necessary.
2330 if (gsym
->needs_plt_entry())
2332 target
->make_plt_entry(symtab
, layout
, gsym
);
2333 // Since this is not a PC-relative relocation, we may be
2334 // taking the address of a function. In that case we need to
2335 // set the entry in the dynamic symbol table to the address of
2337 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2338 gsym
->set_needs_dynsym_value();
2340 // Make a dynamic relocation if necessary.
2341 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2343 if (gsym
->may_need_copy_reloc())
2345 target
->copy_reloc(symtab
, layout
, object
,
2346 data_shndx
, output_section
, gsym
, reloc
);
2348 else if (r_type
== elfcpp::R_X86_64_64
2349 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2350 && gsym
->can_use_relative_reloc(false)
2351 && !gsym
->is_from_dynobj()
2352 && !gsym
->is_undefined()
2353 && !gsym
->is_preemptible())
2355 // Use an IRELATIVE reloc for a locally defined
2356 // STT_GNU_IFUNC symbol. This makes a function
2357 // address in a PIE executable match the address in a
2358 // shared library that it links against.
2359 Reloc_section
* rela_dyn
=
2360 target
->rela_irelative_section(layout
);
2361 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
2362 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
2363 output_section
, object
,
2365 reloc
.get_r_offset(),
2366 reloc
.get_r_addend());
2368 else if (r_type
== elfcpp::R_X86_64_64
2369 && gsym
->can_use_relative_reloc(false))
2371 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2372 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
2373 output_section
, object
,
2375 reloc
.get_r_offset(),
2376 reloc
.get_r_addend());
2380 this->check_non_pic(object
, r_type
, gsym
);
2381 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2382 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2383 data_shndx
, reloc
.get_r_offset(),
2384 reloc
.get_r_addend());
2390 case elfcpp::R_X86_64_PC64
:
2391 case elfcpp::R_X86_64_PC32
:
2392 case elfcpp::R_X86_64_PC16
:
2393 case elfcpp::R_X86_64_PC8
:
2395 // Make a PLT entry if necessary.
2396 if (gsym
->needs_plt_entry())
2397 target
->make_plt_entry(symtab
, layout
, gsym
);
2398 // Make a dynamic relocation if necessary.
2399 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2401 if (gsym
->may_need_copy_reloc())
2403 target
->copy_reloc(symtab
, layout
, object
,
2404 data_shndx
, output_section
, gsym
, reloc
);
2408 this->check_non_pic(object
, r_type
, gsym
);
2409 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2410 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2411 data_shndx
, reloc
.get_r_offset(),
2412 reloc
.get_r_addend());
2418 case elfcpp::R_X86_64_GOT64
:
2419 case elfcpp::R_X86_64_GOT32
:
2420 case elfcpp::R_X86_64_GOTPCREL64
:
2421 case elfcpp::R_X86_64_GOTPCREL
:
2422 case elfcpp::R_X86_64_GOTPLT64
:
2424 // The symbol requires a GOT entry.
2425 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
2426 if (gsym
->final_value_is_known())
2428 // For a STT_GNU_IFUNC symbol we want the PLT address.
2429 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2430 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2432 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2436 // If this symbol is not fully resolved, we need to add a
2437 // dynamic relocation for it.
2438 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2439 if (gsym
->is_from_dynobj()
2440 || gsym
->is_undefined()
2441 || gsym
->is_preemptible()
2442 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2443 && parameters
->options().output_is_position_independent()))
2444 got
->add_global_with_rela(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
2445 elfcpp::R_X86_64_GLOB_DAT
);
2448 // For a STT_GNU_IFUNC symbol we want to write the PLT
2449 // offset into the GOT, so that function pointer
2450 // comparisons work correctly.
2452 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2453 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2456 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2457 // Tell the dynamic linker to use the PLT address
2458 // when resolving relocations.
2459 if (gsym
->is_from_dynobj()
2460 && !parameters
->options().shared())
2461 gsym
->set_needs_dynsym_value();
2465 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2466 rela_dyn
->add_global_relative(gsym
,
2467 elfcpp::R_X86_64_RELATIVE
,
2472 // For GOTPLT64, we also need a PLT entry (but only if the
2473 // symbol is not fully resolved).
2474 if (r_type
== elfcpp::R_X86_64_GOTPLT64
2475 && !gsym
->final_value_is_known())
2476 target
->make_plt_entry(symtab
, layout
, gsym
);
2480 case elfcpp::R_X86_64_PLT32
:
2481 // If the symbol is fully resolved, this is just a PC32 reloc.
2482 // Otherwise we need a PLT entry.
2483 if (gsym
->final_value_is_known())
2485 // If building a shared library, we can also skip the PLT entry
2486 // if the symbol is defined in the output file and is protected
2488 if (gsym
->is_defined()
2489 && !gsym
->is_from_dynobj()
2490 && !gsym
->is_preemptible())
2492 target
->make_plt_entry(symtab
, layout
, gsym
);
2495 case elfcpp::R_X86_64_GOTPC32
:
2496 case elfcpp::R_X86_64_GOTOFF64
:
2497 case elfcpp::R_X86_64_GOTPC64
:
2498 case elfcpp::R_X86_64_PLTOFF64
:
2499 // We need a GOT section.
2500 target
->got_section(symtab
, layout
);
2501 // For PLTOFF64, we also need a PLT entry (but only if the
2502 // symbol is not fully resolved).
2503 if (r_type
== elfcpp::R_X86_64_PLTOFF64
2504 && !gsym
->final_value_is_known())
2505 target
->make_plt_entry(symtab
, layout
, gsym
);
2508 case elfcpp::R_X86_64_COPY
:
2509 case elfcpp::R_X86_64_GLOB_DAT
:
2510 case elfcpp::R_X86_64_JUMP_SLOT
:
2511 case elfcpp::R_X86_64_RELATIVE
:
2512 case elfcpp::R_X86_64_IRELATIVE
:
2513 // These are outstanding tls relocs, which are unexpected when linking
2514 case elfcpp::R_X86_64_TPOFF64
:
2515 case elfcpp::R_X86_64_DTPMOD64
:
2516 case elfcpp::R_X86_64_TLSDESC
:
2517 gold_error(_("%s: unexpected reloc %u in object file"),
2518 object
->name().c_str(), r_type
);
2521 // These are initial tls relocs, which are expected for global()
2522 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2523 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2524 case elfcpp::R_X86_64_TLSDESC_CALL
:
2525 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2526 case elfcpp::R_X86_64_DTPOFF32
:
2527 case elfcpp::R_X86_64_DTPOFF64
:
2528 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2529 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2531 const bool is_final
= gsym
->final_value_is_known();
2532 const tls::Tls_optimization optimized_type
2533 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
2536 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
2537 if (optimized_type
== tls::TLSOPT_NONE
)
2539 // Create a pair of GOT entries for the module index and
2540 // dtv-relative offset.
2541 Output_data_got
<64, false>* got
2542 = target
->got_section(symtab
, layout
);
2543 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_PAIR
,
2544 target
->rela_dyn_section(layout
),
2545 elfcpp::R_X86_64_DTPMOD64
,
2546 elfcpp::R_X86_64_DTPOFF64
);
2548 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2550 // Create a GOT entry for the tp-relative offset.
2551 Output_data_got
<64, false>* got
2552 = target
->got_section(symtab
, layout
);
2553 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2554 target
->rela_dyn_section(layout
),
2555 elfcpp::R_X86_64_TPOFF64
);
2557 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2558 unsupported_reloc_global(object
, r_type
, gsym
);
2561 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2562 target
->define_tls_base_symbol(symtab
, layout
);
2563 if (optimized_type
== tls::TLSOPT_NONE
)
2565 // Create reserved PLT and GOT entries for the resolver.
2566 target
->reserve_tlsdesc_entries(symtab
, layout
);
2568 // Create a double GOT entry with an R_X86_64_TLSDESC
2569 // reloc. The R_X86_64_TLSDESC reloc is resolved
2570 // lazily, so the GOT entry needs to be in an area in
2571 // .got.plt, not .got. Call got_section to make sure
2572 // the section has been created.
2573 target
->got_section(symtab
, layout
);
2574 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
2575 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
2576 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2577 elfcpp::R_X86_64_TLSDESC
, 0);
2579 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2581 // Create a GOT entry for the tp-relative offset.
2582 Output_data_got
<64, false>* got
2583 = target
->got_section(symtab
, layout
);
2584 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2585 target
->rela_dyn_section(layout
),
2586 elfcpp::R_X86_64_TPOFF64
);
2588 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2589 unsupported_reloc_global(object
, r_type
, gsym
);
2592 case elfcpp::R_X86_64_TLSDESC_CALL
:
2595 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2596 if (optimized_type
== tls::TLSOPT_NONE
)
2598 // Create a GOT entry for the module index.
2599 target
->got_mod_index_entry(symtab
, layout
, object
);
2601 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2602 unsupported_reloc_global(object
, r_type
, gsym
);
2605 case elfcpp::R_X86_64_DTPOFF32
:
2606 case elfcpp::R_X86_64_DTPOFF64
:
2609 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2610 layout
->set_has_static_tls();
2611 if (optimized_type
== tls::TLSOPT_NONE
)
2613 // Create a GOT entry for the tp-relative offset.
2614 Output_data_got
<64, false>* got
2615 = target
->got_section(symtab
, layout
);
2616 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2617 target
->rela_dyn_section(layout
),
2618 elfcpp::R_X86_64_TPOFF64
);
2620 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2621 unsupported_reloc_global(object
, r_type
, gsym
);
2624 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2625 layout
->set_has_static_tls();
2626 if (parameters
->options().shared())
2627 unsupported_reloc_local(object
, r_type
);
2636 case elfcpp::R_X86_64_SIZE32
:
2637 case elfcpp::R_X86_64_SIZE64
:
2639 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2640 object
->name().c_str(), r_type
,
2641 gsym
->demangled_name().c_str());
2647 Target_x86_64::gc_process_relocs(Symbol_table
* symtab
,
2649 Sized_relobj_file
<64, false>* object
,
2650 unsigned int data_shndx
,
2651 unsigned int sh_type
,
2652 const unsigned char* prelocs
,
2654 Output_section
* output_section
,
2655 bool needs_special_offset_handling
,
2656 size_t local_symbol_count
,
2657 const unsigned char* plocal_symbols
)
2660 if (sh_type
== elfcpp::SHT_REL
)
2665 gold::gc_process_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2666 Target_x86_64::Scan
,
2667 Target_x86_64::Relocatable_size_for_reloc
>(
2676 needs_special_offset_handling
,
2681 // Scan relocations for a section.
2684 Target_x86_64::scan_relocs(Symbol_table
* symtab
,
2686 Sized_relobj_file
<64, false>* object
,
2687 unsigned int data_shndx
,
2688 unsigned int sh_type
,
2689 const unsigned char* prelocs
,
2691 Output_section
* output_section
,
2692 bool needs_special_offset_handling
,
2693 size_t local_symbol_count
,
2694 const unsigned char* plocal_symbols
)
2696 if (sh_type
== elfcpp::SHT_REL
)
2698 gold_error(_("%s: unsupported REL reloc section"),
2699 object
->name().c_str());
2703 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2704 Target_x86_64::Scan
>(
2713 needs_special_offset_handling
,
2718 // Finalize the sections.
2721 Target_x86_64::do_finalize_sections(
2723 const Input_objects
*,
2724 Symbol_table
* symtab
)
2726 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2728 : this->plt_
->rela_plt());
2729 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
2730 this->rela_dyn_
, true, false);
2732 // Fill in some more dynamic tags.
2733 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
2736 if (this->plt_
!= NULL
2737 && this->plt_
->output_section() != NULL
2738 && this->plt_
->has_tlsdesc_entry())
2740 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
2741 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
2742 this->got_
->finalize_data_size();
2743 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
2744 this->plt_
, plt_offset
);
2745 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
2746 this->got_
, got_offset
);
2750 // Emit any relocs we saved in an attempt to avoid generating COPY
2752 if (this->copy_relocs_
.any_saved_relocs())
2753 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
2755 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2756 // the .got.plt section.
2757 Symbol
* sym
= this->global_offset_table_
;
2760 uint64_t data_size
= this->got_plt_
->current_data_size();
2761 symtab
->get_sized_symbol
<64>(sym
)->set_symsize(data_size
);
2764 if (parameters
->doing_static_link()
2765 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2767 // If linking statically, make sure that the __rela_iplt symbols
2768 // were defined if necessary, even if we didn't create a PLT.
2769 static const Define_symbol_in_segment syms
[] =
2772 "__rela_iplt_start", // name
2773 elfcpp::PT_LOAD
, // segment_type
2774 elfcpp::PF_W
, // segment_flags_set
2775 elfcpp::PF(0), // segment_flags_clear
2778 elfcpp::STT_NOTYPE
, // type
2779 elfcpp::STB_GLOBAL
, // binding
2780 elfcpp::STV_HIDDEN
, // visibility
2782 Symbol::SEGMENT_START
, // offset_from_base
2786 "__rela_iplt_end", // name
2787 elfcpp::PT_LOAD
, // segment_type
2788 elfcpp::PF_W
, // segment_flags_set
2789 elfcpp::PF(0), // segment_flags_clear
2792 elfcpp::STT_NOTYPE
, // type
2793 elfcpp::STB_GLOBAL
, // binding
2794 elfcpp::STV_HIDDEN
, // visibility
2796 Symbol::SEGMENT_START
, // offset_from_base
2801 symtab
->define_symbols(layout
, 2, syms
,
2802 layout
->script_options()->saw_sections_clause());
2806 // Perform a relocation.
2809 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
2810 Target_x86_64
* target
,
2813 const elfcpp::Rela
<64, false>& rela
,
2814 unsigned int r_type
,
2815 const Sized_symbol
<64>* gsym
,
2816 const Symbol_value
<64>* psymval
,
2817 unsigned char* view
,
2818 elfcpp::Elf_types
<64>::Elf_Addr address
,
2819 section_size_type view_size
)
2821 if (this->skip_call_tls_get_addr_
)
2823 if ((r_type
!= elfcpp::R_X86_64_PLT32
2824 && r_type
!= elfcpp::R_X86_64_PC32
)
2826 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
2828 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2829 _("missing expected TLS relocation"));
2833 this->skip_call_tls_get_addr_
= false;
2838 const Sized_relobj_file
<64, false>* object
= relinfo
->object
;
2840 // Pick the value to use for symbols defined in the PLT.
2841 Symbol_value
<64> symval
;
2843 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2845 symval
.set_output_value(target
->plt_address_for_global(gsym
)
2846 + gsym
->plt_offset());
2849 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2851 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2852 if (object
->local_has_plt_offset(r_sym
))
2854 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
)
2855 + object
->local_plt_offset(r_sym
));
2860 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2862 // Get the GOT offset if needed.
2863 // The GOT pointer points to the end of the GOT section.
2864 // We need to subtract the size of the GOT section to get
2865 // the actual offset to use in the relocation.
2866 bool have_got_offset
= false;
2867 unsigned int got_offset
= 0;
2870 case elfcpp::R_X86_64_GOT32
:
2871 case elfcpp::R_X86_64_GOT64
:
2872 case elfcpp::R_X86_64_GOTPLT64
:
2873 case elfcpp::R_X86_64_GOTPCREL
:
2874 case elfcpp::R_X86_64_GOTPCREL64
:
2877 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2878 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
2882 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2883 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2884 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2885 - target
->got_size());
2887 have_got_offset
= true;
2896 case elfcpp::R_X86_64_NONE
:
2897 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2898 case elfcpp::R_X86_64_GNU_VTENTRY
:
2901 case elfcpp::R_X86_64_64
:
2902 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
2905 case elfcpp::R_X86_64_PC64
:
2906 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
2910 case elfcpp::R_X86_64_32
:
2911 // FIXME: we need to verify that value + addend fits into 32 bits:
2912 // uint64_t x = value + addend;
2913 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
2914 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
2915 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
2918 case elfcpp::R_X86_64_32S
:
2919 // FIXME: we need to verify that value + addend fits into 32 bits:
2920 // int64_t x = value + addend; // note this quantity is signed!
2921 // x == static_cast<int64_t>(static_cast<int32_t>(x))
2922 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
2925 case elfcpp::R_X86_64_PC32
:
2926 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2930 case elfcpp::R_X86_64_16
:
2931 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
2934 case elfcpp::R_X86_64_PC16
:
2935 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
2939 case elfcpp::R_X86_64_8
:
2940 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
2943 case elfcpp::R_X86_64_PC8
:
2944 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
2948 case elfcpp::R_X86_64_PLT32
:
2949 gold_assert(gsym
== NULL
2950 || gsym
->has_plt_offset()
2951 || gsym
->final_value_is_known()
2952 || (gsym
->is_defined()
2953 && !gsym
->is_from_dynobj()
2954 && !gsym
->is_preemptible()));
2955 // Note: while this code looks the same as for R_X86_64_PC32, it
2956 // behaves differently because psymval was set to point to
2957 // the PLT entry, rather than the symbol, in Scan::global().
2958 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2962 case elfcpp::R_X86_64_PLTOFF64
:
2965 gold_assert(gsym
->has_plt_offset()
2966 || gsym
->final_value_is_known());
2967 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
2968 got_address
= target
->got_section(NULL
, NULL
)->address();
2969 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
2970 addend
- got_address
);
2973 case elfcpp::R_X86_64_GOT32
:
2974 gold_assert(have_got_offset
);
2975 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
2978 case elfcpp::R_X86_64_GOTPC32
:
2981 elfcpp::Elf_types
<64>::Elf_Addr value
;
2982 value
= target
->got_plt_section()->address();
2983 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2987 case elfcpp::R_X86_64_GOT64
:
2988 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
2989 // Since we always add a PLT entry, this is equivalent.
2990 case elfcpp::R_X86_64_GOTPLT64
:
2991 gold_assert(have_got_offset
);
2992 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
2995 case elfcpp::R_X86_64_GOTPC64
:
2998 elfcpp::Elf_types
<64>::Elf_Addr value
;
2999 value
= target
->got_plt_section()->address();
3000 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
3004 case elfcpp::R_X86_64_GOTOFF64
:
3006 elfcpp::Elf_types
<64>::Elf_Addr value
;
3007 value
= (psymval
->value(object
, 0)
3008 - target
->got_plt_section()->address());
3009 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
3013 case elfcpp::R_X86_64_GOTPCREL
:
3015 gold_assert(have_got_offset
);
3016 elfcpp::Elf_types
<64>::Elf_Addr value
;
3017 value
= target
->got_plt_section()->address() + got_offset
;
3018 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
3022 case elfcpp::R_X86_64_GOTPCREL64
:
3024 gold_assert(have_got_offset
);
3025 elfcpp::Elf_types
<64>::Elf_Addr value
;
3026 value
= target
->got_plt_section()->address() + got_offset
;
3027 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
3031 case elfcpp::R_X86_64_COPY
:
3032 case elfcpp::R_X86_64_GLOB_DAT
:
3033 case elfcpp::R_X86_64_JUMP_SLOT
:
3034 case elfcpp::R_X86_64_RELATIVE
:
3035 case elfcpp::R_X86_64_IRELATIVE
:
3036 // These are outstanding tls relocs, which are unexpected when linking
3037 case elfcpp::R_X86_64_TPOFF64
:
3038 case elfcpp::R_X86_64_DTPMOD64
:
3039 case elfcpp::R_X86_64_TLSDESC
:
3040 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3041 _("unexpected reloc %u in object file"),
3045 // These are initial tls relocs, which are expected when linking
3046 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3047 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3048 case elfcpp::R_X86_64_TLSDESC_CALL
:
3049 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3050 case elfcpp::R_X86_64_DTPOFF32
:
3051 case elfcpp::R_X86_64_DTPOFF64
:
3052 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3053 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3054 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
3055 view
, address
, view_size
);
3058 case elfcpp::R_X86_64_SIZE32
:
3059 case elfcpp::R_X86_64_SIZE64
:
3061 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3062 _("unsupported reloc %u"),
3070 // Perform a TLS relocation.
3073 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
3074 Target_x86_64
* target
,
3076 const elfcpp::Rela
<64, false>& rela
,
3077 unsigned int r_type
,
3078 const Sized_symbol
<64>* gsym
,
3079 const Symbol_value
<64>* psymval
,
3080 unsigned char* view
,
3081 elfcpp::Elf_types
<64>::Elf_Addr address
,
3082 section_size_type view_size
)
3084 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3086 const Sized_relobj_file
<64, false>* object
= relinfo
->object
;
3087 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3088 elfcpp::Shdr
<64, false> data_shdr(relinfo
->data_shdr
);
3089 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
3091 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
3093 const bool is_final
= (gsym
== NULL
3094 ? !parameters
->options().shared()
3095 : gsym
->final_value_is_known());
3096 tls::Tls_optimization optimized_type
3097 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
3100 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3101 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3103 // If this code sequence is used in a non-executable section,
3104 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3105 // on the assumption that it's being used by itself in a debug
3106 // section. Therefore, in the unlikely event that the code
3107 // sequence appears in a non-executable section, we simply
3108 // leave it unoptimized.
3109 optimized_type
= tls::TLSOPT_NONE
;
3111 if (optimized_type
== tls::TLSOPT_TO_LE
)
3113 if (tls_segment
== NULL
)
3115 gold_assert(parameters
->errors()->error_count() > 0
3116 || issue_undefined_symbol_error(gsym
));
3119 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3120 rela
, r_type
, value
, view
,
3126 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3127 ? GOT_TYPE_TLS_OFFSET
3128 : GOT_TYPE_TLS_PAIR
);
3129 unsigned int got_offset
;
3132 gold_assert(gsym
->has_got_offset(got_type
));
3133 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3137 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
3138 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3139 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3140 - target
->got_size());
3142 if (optimized_type
== tls::TLSOPT_TO_IE
)
3144 if (tls_segment
== NULL
)
3146 gold_assert(parameters
->errors()->error_count() > 0
3147 || issue_undefined_symbol_error(gsym
));
3150 value
= target
->got_plt_section()->address() + got_offset
;
3151 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
3152 value
, view
, address
, view_size
);
3155 else if (optimized_type
== tls::TLSOPT_NONE
)
3157 // Relocate the field with the offset of the pair of GOT
3159 value
= target
->got_plt_section()->address() + got_offset
;
3160 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
3165 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3166 _("unsupported reloc %u"), r_type
);
3169 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3170 case elfcpp::R_X86_64_TLSDESC_CALL
:
3171 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3173 // See above comment for R_X86_64_TLSGD.
3174 optimized_type
= tls::TLSOPT_NONE
;
3176 if (optimized_type
== tls::TLSOPT_TO_LE
)
3178 if (tls_segment
== NULL
)
3180 gold_assert(parameters
->errors()->error_count() > 0
3181 || issue_undefined_symbol_error(gsym
));
3184 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3185 rela
, r_type
, value
, view
,
3191 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3192 ? GOT_TYPE_TLS_OFFSET
3193 : GOT_TYPE_TLS_DESC
);
3194 unsigned int got_offset
= 0;
3195 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
3196 && optimized_type
== tls::TLSOPT_NONE
)
3198 // We created GOT entries in the .got.tlsdesc portion of
3199 // the .got.plt section, but the offset stored in the
3200 // symbol is the offset within .got.tlsdesc.
3201 got_offset
= (target
->got_size()
3202 + target
->got_plt_section()->data_size());
3206 gold_assert(gsym
->has_got_offset(got_type
));
3207 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3211 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
3212 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3213 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3214 - target
->got_size());
3216 if (optimized_type
== tls::TLSOPT_TO_IE
)
3218 if (tls_segment
== NULL
)
3220 gold_assert(parameters
->errors()->error_count() > 0
3221 || issue_undefined_symbol_error(gsym
));
3224 value
= target
->got_plt_section()->address() + got_offset
;
3225 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
,
3226 rela
, r_type
, value
, view
, address
,
3230 else if (optimized_type
== tls::TLSOPT_NONE
)
3232 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
3234 // Relocate the field with the offset of the pair of GOT
3236 value
= target
->got_plt_section()->address() + got_offset
;
3237 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
3243 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3244 _("unsupported reloc %u"), r_type
);
3247 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3248 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
3250 // See above comment for R_X86_64_TLSGD.
3251 optimized_type
= tls::TLSOPT_NONE
;
3253 if (optimized_type
== tls::TLSOPT_TO_LE
)
3255 if (tls_segment
== NULL
)
3257 gold_assert(parameters
->errors()->error_count() > 0
3258 || issue_undefined_symbol_error(gsym
));
3261 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
3262 value
, view
, view_size
);
3265 else if (optimized_type
== tls::TLSOPT_NONE
)
3267 // Relocate the field with the offset of the GOT entry for
3268 // the module index.
3269 unsigned int got_offset
;
3270 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3271 - target
->got_size());
3272 value
= target
->got_plt_section()->address() + got_offset
;
3273 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
3277 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3278 _("unsupported reloc %u"), r_type
);
3281 case elfcpp::R_X86_64_DTPOFF32
:
3282 // This relocation type is used in debugging information.
3283 // In that case we need to not optimize the value. If the
3284 // section is not executable, then we assume we should not
3285 // optimize this reloc. See comments above for R_X86_64_TLSGD,
3286 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3288 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
3290 if (tls_segment
== NULL
)
3292 gold_assert(parameters
->errors()->error_count() > 0
3293 || issue_undefined_symbol_error(gsym
));
3296 value
-= tls_segment
->memsz();
3298 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
3301 case elfcpp::R_X86_64_DTPOFF64
:
3302 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3303 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
3305 if (tls_segment
== NULL
)
3307 gold_assert(parameters
->errors()->error_count() > 0
3308 || issue_undefined_symbol_error(gsym
));
3311 value
-= tls_segment
->memsz();
3313 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
3316 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3317 if (optimized_type
== tls::TLSOPT_TO_LE
)
3319 if (tls_segment
== NULL
)
3321 gold_assert(parameters
->errors()->error_count() > 0
3322 || issue_undefined_symbol_error(gsym
));
3325 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3326 rela
, r_type
, value
, view
,
3330 else if (optimized_type
== tls::TLSOPT_NONE
)
3332 // Relocate the field with the offset of the GOT entry for
3333 // the tp-relative offset of the symbol.
3334 unsigned int got_offset
;
3337 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
3338 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
3339 - target
->got_size());
3343 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
3344 gold_assert(object
->local_has_got_offset(r_sym
,
3345 GOT_TYPE_TLS_OFFSET
));
3346 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
3347 - target
->got_size());
3349 value
= target
->got_plt_section()->address() + got_offset
;
3350 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
3353 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
3354 _("unsupported reloc type %u"),
3358 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3359 if (tls_segment
== NULL
)
3361 gold_assert(parameters
->errors()->error_count() > 0
3362 || issue_undefined_symbol_error(gsym
));
3365 value
-= tls_segment
->memsz();
3366 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
3371 // Do a relocation in which we convert a TLS General-Dynamic to an
3375 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info
<64, false>* relinfo
,
3378 const elfcpp::Rela
<64, false>& rela
,
3380 elfcpp::Elf_types
<64>::Elf_Addr value
,
3381 unsigned char* view
,
3382 elfcpp::Elf_types
<64>::Elf_Addr address
,
3383 section_size_type view_size
)
3385 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3386 // .word 0x6666; rex64; call __tls_get_addr
3387 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3389 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
3390 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
3392 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3393 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
3394 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3395 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
3397 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
3399 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3400 Relocate_functions
<64, false>::pcrela32(view
+ 8, value
, addend
- 8, address
);
3402 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3404 this->skip_call_tls_get_addr_
= true;
3407 // Do a relocation in which we convert a TLS General-Dynamic to a
3411 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
3413 Output_segment
* tls_segment
,
3414 const elfcpp::Rela
<64, false>& rela
,
3416 elfcpp::Elf_types
<64>::Elf_Addr value
,
3417 unsigned char* view
,
3418 section_size_type view_size
)
3420 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3421 // .word 0x6666; rex64; call __tls_get_addr
3422 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
3424 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
3425 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
3427 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3428 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
3429 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3430 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
3432 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
3434 value
-= tls_segment
->memsz();
3435 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
3437 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3439 this->skip_call_tls_get_addr_
= true;
3442 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
3445 Target_x86_64::Relocate::tls_desc_gd_to_ie(
3446 const Relocate_info
<64, false>* relinfo
,
3449 const elfcpp::Rela
<64, false>& rela
,
3450 unsigned int r_type
,
3451 elfcpp::Elf_types
<64>::Elf_Addr value
,
3452 unsigned char* view
,
3453 elfcpp::Elf_types
<64>::Elf_Addr address
,
3454 section_size_type view_size
)
3456 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
3458 // leaq foo@tlsdesc(%rip), %rax
3459 // ==> movq foo@gottpoff(%rip), %rax
3460 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
3461 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
3462 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3463 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
3465 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
3466 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
3470 // call *foo@tlscall(%rax)
3472 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
3473 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
3474 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3475 view
[0] == 0xff && view
[1] == 0x10);
3481 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
3484 Target_x86_64::Relocate::tls_desc_gd_to_le(
3485 const Relocate_info
<64, false>* relinfo
,
3487 Output_segment
* tls_segment
,
3488 const elfcpp::Rela
<64, false>& rela
,
3489 unsigned int r_type
,
3490 elfcpp::Elf_types
<64>::Elf_Addr value
,
3491 unsigned char* view
,
3492 section_size_type view_size
)
3494 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
3496 // leaq foo@tlsdesc(%rip), %rax
3497 // ==> movq foo@tpoff, %rax
3498 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
3499 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
3500 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3501 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
3504 value
-= tls_segment
->memsz();
3505 Relocate_functions
<64, false>::rela32(view
, value
, 0);
3509 // call *foo@tlscall(%rax)
3511 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
3512 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
3513 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3514 view
[0] == 0xff && view
[1] == 0x10);
3521 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
3524 const elfcpp::Rela
<64, false>& rela
,
3526 elfcpp::Elf_types
<64>::Elf_Addr
,
3527 unsigned char* view
,
3528 section_size_type view_size
)
3530 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
3531 // ... leq foo@dtpoff(%rax),%reg
3532 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
3534 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
3535 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
3537 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
3538 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
3540 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
3542 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
3544 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3546 this->skip_call_tls_get_addr_
= true;
3549 // Do a relocation in which we convert a TLS Initial-Exec to a
3553 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
3555 Output_segment
* tls_segment
,
3556 const elfcpp::Rela
<64, false>& rela
,
3558 elfcpp::Elf_types
<64>::Elf_Addr value
,
3559 unsigned char* view
,
3560 section_size_type view_size
)
3562 // We need to examine the opcodes to figure out which instruction we
3565 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
3566 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
3568 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
3569 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
3571 unsigned char op1
= view
[-3];
3572 unsigned char op2
= view
[-2];
3573 unsigned char op3
= view
[-1];
3574 unsigned char reg
= op3
>> 3;
3582 view
[-1] = 0xc0 | reg
;
3586 // Special handling for %rsp.
3590 view
[-1] = 0xc0 | reg
;
3598 view
[-1] = 0x80 | reg
| (reg
<< 3);
3601 value
-= tls_segment
->memsz();
3602 Relocate_functions
<64, false>::rela32(view
, value
, 0);
3605 // Relocate section data.
3608 Target_x86_64::relocate_section(
3609 const Relocate_info
<64, false>* relinfo
,
3610 unsigned int sh_type
,
3611 const unsigned char* prelocs
,
3613 Output_section
* output_section
,
3614 bool needs_special_offset_handling
,
3615 unsigned char* view
,
3616 elfcpp::Elf_types
<64>::Elf_Addr address
,
3617 section_size_type view_size
,
3618 const Reloc_symbol_changes
* reloc_symbol_changes
)
3620 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3622 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
3623 Target_x86_64::Relocate
>(
3629 needs_special_offset_handling
,
3633 reloc_symbol_changes
);
3636 // Apply an incremental relocation. Incremental relocations always refer
3637 // to global symbols.
3640 Target_x86_64::apply_relocation(
3641 const Relocate_info
<64, false>* relinfo
,
3642 elfcpp::Elf_types
<64>::Elf_Addr r_offset
,
3643 unsigned int r_type
,
3644 elfcpp::Elf_types
<64>::Elf_Swxword r_addend
,
3646 unsigned char* view
,
3647 elfcpp::Elf_types
<64>::Elf_Addr address
,
3648 section_size_type view_size
)
3650 gold::apply_relocation
<64, false, Target_x86_64
, Target_x86_64::Relocate
>(
3662 // Return the size of a relocation while scanning during a relocatable
3666 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
3667 unsigned int r_type
,
3672 case elfcpp::R_X86_64_NONE
:
3673 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3674 case elfcpp::R_X86_64_GNU_VTENTRY
:
3675 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3676 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3677 case elfcpp::R_X86_64_TLSDESC_CALL
:
3678 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3679 case elfcpp::R_X86_64_DTPOFF32
:
3680 case elfcpp::R_X86_64_DTPOFF64
:
3681 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3682 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3685 case elfcpp::R_X86_64_64
:
3686 case elfcpp::R_X86_64_PC64
:
3687 case elfcpp::R_X86_64_GOTOFF64
:
3688 case elfcpp::R_X86_64_GOTPC64
:
3689 case elfcpp::R_X86_64_PLTOFF64
:
3690 case elfcpp::R_X86_64_GOT64
:
3691 case elfcpp::R_X86_64_GOTPCREL64
:
3692 case elfcpp::R_X86_64_GOTPCREL
:
3693 case elfcpp::R_X86_64_GOTPLT64
:
3696 case elfcpp::R_X86_64_32
:
3697 case elfcpp::R_X86_64_32S
:
3698 case elfcpp::R_X86_64_PC32
:
3699 case elfcpp::R_X86_64_PLT32
:
3700 case elfcpp::R_X86_64_GOTPC32
:
3701 case elfcpp::R_X86_64_GOT32
:
3704 case elfcpp::R_X86_64_16
:
3705 case elfcpp::R_X86_64_PC16
:
3708 case elfcpp::R_X86_64_8
:
3709 case elfcpp::R_X86_64_PC8
:
3712 case elfcpp::R_X86_64_COPY
:
3713 case elfcpp::R_X86_64_GLOB_DAT
:
3714 case elfcpp::R_X86_64_JUMP_SLOT
:
3715 case elfcpp::R_X86_64_RELATIVE
:
3716 case elfcpp::R_X86_64_IRELATIVE
:
3717 // These are outstanding tls relocs, which are unexpected when linking
3718 case elfcpp::R_X86_64_TPOFF64
:
3719 case elfcpp::R_X86_64_DTPMOD64
:
3720 case elfcpp::R_X86_64_TLSDESC
:
3721 object
->error(_("unexpected reloc %u in object file"), r_type
);
3724 case elfcpp::R_X86_64_SIZE32
:
3725 case elfcpp::R_X86_64_SIZE64
:
3727 object
->error(_("unsupported reloc %u against local symbol"), r_type
);
3732 // Scan the relocs during a relocatable link.
3735 Target_x86_64::scan_relocatable_relocs(Symbol_table
* symtab
,
3737 Sized_relobj_file
<64, false>* object
,
3738 unsigned int data_shndx
,
3739 unsigned int sh_type
,
3740 const unsigned char* prelocs
,
3742 Output_section
* output_section
,
3743 bool needs_special_offset_handling
,
3744 size_t local_symbol_count
,
3745 const unsigned char* plocal_symbols
,
3746 Relocatable_relocs
* rr
)
3748 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3750 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_RELA
,
3751 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3753 gold::scan_relocatable_relocs
<64, false, elfcpp::SHT_RELA
,
3754 Scan_relocatable_relocs
>(
3762 needs_special_offset_handling
,
3768 // Relocate a section during a relocatable link.
3771 Target_x86_64::relocate_for_relocatable(
3772 const Relocate_info
<64, false>* relinfo
,
3773 unsigned int sh_type
,
3774 const unsigned char* prelocs
,
3776 Output_section
* output_section
,
3777 off_t offset_in_output_section
,
3778 const Relocatable_relocs
* rr
,
3779 unsigned char* view
,
3780 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
3781 section_size_type view_size
,
3782 unsigned char* reloc_view
,
3783 section_size_type reloc_view_size
)
3785 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3787 gold::relocate_for_relocatable
<64, false, elfcpp::SHT_RELA
>(
3792 offset_in_output_section
,
3801 // Return the value to use for a dynamic which requires special
3802 // treatment. This is how we support equality comparisons of function
3803 // pointers across shared library boundaries, as described in the
3804 // processor specific ABI supplement.
3807 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
3809 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3810 return this->plt_address_for_global(gsym
) + gsym
->plt_offset();
3813 // Return a string used to fill a code section with nops to take up
3814 // the specified length.
3817 Target_x86_64::do_code_fill(section_size_type length
) const
3821 // Build a jmpq instruction to skip over the bytes.
3822 unsigned char jmp
[5];
3824 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3825 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3826 + std::string(length
- 5, '\0'));
3829 // Nop sequences of various lengths.
3830 const char nop1
[1] = { 0x90 }; // nop
3831 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
3832 const char nop3
[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
3833 const char nop4
[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
3834 const char nop5
[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
3836 const char nop6
[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
3838 const char nop7
[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
3840 const char nop8
[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
3841 0x00, 0x00, 0x00, 0x00 };
3842 const char nop9
[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
3843 0x00, 0x00, 0x00, 0x00,
3845 const char nop10
[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
3846 0x84, 0x00, 0x00, 0x00,
3848 const char nop11
[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
3849 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3851 const char nop12
[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
3852 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
3853 0x00, 0x00, 0x00, 0x00 };
3854 const char nop13
[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3855 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
3856 0x00, 0x00, 0x00, 0x00,
3858 const char nop14
[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3859 0x66, 0x2e, 0x0f, 0x1f, // data16
3860 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3862 const char nop15
[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3863 0x66, 0x66, 0x2e, 0x0f, // data16; data16
3864 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3867 const char* nops
[16] = {
3869 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3870 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3873 return std::string(nops
[length
], length
);
3876 // Return the addend to use for a target specific relocation. The
3877 // only target specific relocation is R_X86_64_TLSDESC for a local
3878 // symbol. We want to set the addend is the offset of the local
3879 // symbol in the TLS segment.
3882 Target_x86_64::do_reloc_addend(void* arg
, unsigned int r_type
,
3885 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
3886 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
3887 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
3888 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
3889 const Symbol_value
<64>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
3890 gold_assert(psymval
->is_tls_symbol());
3891 // The value of a TLS symbol is the offset in the TLS segment.
3892 return psymval
->value(ti
.object
, 0);
3895 // Return the value to use for the base of a DW_EH_PE_datarel offset
3896 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3897 // assembler can not write out the difference between two labels in
3898 // different sections, so instead of using a pc-relative value they
3899 // use an offset from the GOT.
3902 Target_x86_64::do_ehframe_datarel_base() const
3904 gold_assert(this->global_offset_table_
!= NULL
);
3905 Symbol
* sym
= this->global_offset_table_
;
3906 Sized_symbol
<64>* ssym
= static_cast<Sized_symbol
<64>*>(sym
);
3907 return ssym
->value();
3910 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3911 // compiled with -fsplit-stack. The function calls non-split-stack
3912 // code. We have to change the function so that it always ensures
3913 // that it has enough stack space to run some random function.
3916 Target_x86_64::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3917 section_offset_type fnoffset
,
3918 section_size_type fnsize
,
3919 unsigned char* view
,
3920 section_size_type view_size
,
3922 std::string
* to
) const
3924 // The function starts with a comparison of the stack pointer and a
3925 // field in the TCB. This is followed by a jump.
3928 if (this->match_view(view
, view_size
, fnoffset
, "\x64\x48\x3b\x24\x25", 5)
3931 // We will call __morestack if the carry flag is set after this
3932 // comparison. We turn the comparison into an stc instruction
3934 view
[fnoffset
] = '\xf9';
3935 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 8);
3937 // lea NN(%rsp),%r10
3938 // lea NN(%rsp),%r11
3939 else if ((this->match_view(view
, view_size
, fnoffset
,
3940 "\x4c\x8d\x94\x24", 4)
3941 || this->match_view(view
, view_size
, fnoffset
,
3942 "\x4c\x8d\x9c\x24", 4))
3945 // This is loading an offset from the stack pointer for a
3946 // comparison. The offset is negative, so we decrease the
3947 // offset by the amount of space we need for the stack. This
3948 // means we will avoid calling __morestack if there happens to
3949 // be plenty of space on the stack already.
3950 unsigned char* pval
= view
+ fnoffset
+ 4;
3951 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3952 val
-= parameters
->options().split_stack_adjust_size();
3953 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3957 if (!object
->has_no_split_stack())
3958 object
->error(_("failed to match split-stack sequence at "
3959 "section %u offset %0zx"),
3960 shndx
, static_cast<size_t>(fnoffset
));
3964 // We have to change the function so that it calls
3965 // __morestack_non_split instead of __morestack. The former will
3966 // allocate additional stack space.
3967 *from
= "__morestack";
3968 *to
= "__morestack_non_split";
3971 // The selector for x86_64 object files.
3973 class Target_selector_x86_64
: public Target_selector_freebsd
3976 Target_selector_x86_64()
3977 : Target_selector_freebsd(elfcpp::EM_X86_64
, 64, false, "elf64-x86-64",
3978 "elf64-x86-64-freebsd", "elf_x86_64")
3982 do_instantiate_target()
3983 { return new Target_x86_64(); }
3987 Target_selector_x86_64 target_selector_x86_64
;
3989 } // End anonymous namespace.