1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright (C) 2006-2015 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
51 // A class to handle the .got.plt section.
53 class Output_data_got_plt_x86_64 : public Output_section_data_build
56 Output_data_got_plt_x86_64(Layout* layout)
57 : Output_section_data_build(8),
61 Output_data_got_plt_x86_64(Layout* layout, off_t data_size)
62 : Output_section_data_build(data_size, 8),
67 // Write out the PLT data.
69 do_write(Output_file*);
71 // Write to a map file.
73 do_print_to_mapfile(Mapfile* mapfile) const
74 { mapfile->print_output_data(this, "** GOT PLT"); }
77 // A pointer to the Layout class, so that we can find the .dynamic
78 // section when we write out the GOT PLT section.
82 // A class to handle the PLT data.
83 // This is an abstract base class that handles most of the linker details
84 // but does not know the actual contents of PLT entries. The derived
85 // classes below fill in those details.
88 class Output_data_plt_x86_64 : public Output_section_data
91 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
93 Output_data_plt_x86_64(Layout* layout, uint64_t addralign,
94 Output_data_got<64, false>* got,
95 Output_data_got_plt_x86_64* got_plt,
96 Output_data_space* got_irelative)
97 : Output_section_data(addralign), tlsdesc_rel_(NULL),
98 irelative_rel_(NULL), got_(got), got_plt_(got_plt),
99 got_irelative_(got_irelative), count_(0), irelative_count_(0),
100 tlsdesc_got_offset_(-1U), free_list_()
101 { this->init(layout); }
103 Output_data_plt_x86_64(Layout* layout, uint64_t plt_entry_size,
104 Output_data_got<64, false>* got,
105 Output_data_got_plt_x86_64* got_plt,
106 Output_data_space* got_irelative,
107 unsigned int plt_count)
108 : Output_section_data((plt_count + 1) * plt_entry_size,
109 plt_entry_size, false),
110 tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
111 got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
112 irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
116 // Initialize the free list and reserve the first entry.
117 this->free_list_.init((plt_count + 1) * plt_entry_size, false);
118 this->free_list_.remove(0, plt_entry_size);
121 // Initialize the PLT section.
123 init(Layout* layout);
125 // Add an entry to the PLT.
127 add_entry(Symbol_table*, Layout*, Symbol* gsym);
129 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
131 add_local_ifunc_entry(Symbol_table* symtab, Layout*,
132 Sized_relobj_file<size, false>* relobj,
133 unsigned int local_sym_index);
135 // Add the relocation for a PLT entry.
137 add_relocation(Symbol_table*, Layout*, Symbol* gsym,
138 unsigned int got_offset);
140 // Add the reserved TLSDESC_PLT entry to the PLT.
142 reserve_tlsdesc_entry(unsigned int got_offset)
143 { this->tlsdesc_got_offset_ = got_offset; }
145 // Return true if a TLSDESC_PLT entry has been reserved.
147 has_tlsdesc_entry() const
148 { return this->tlsdesc_got_offset_ != -1U; }
150 // Return the GOT offset for the reserved TLSDESC_PLT entry.
152 get_tlsdesc_got_offset() const
153 { return this->tlsdesc_got_offset_; }
155 // Return the offset of the reserved TLSDESC_PLT entry.
157 get_tlsdesc_plt_offset() const
159 return ((this->count_ + this->irelative_count_ + 1)
160 * this->get_plt_entry_size());
163 // Return the .rela.plt section data.
166 { return this->rel_; }
168 // Return where the TLSDESC relocations should go.
170 rela_tlsdesc(Layout*);
172 // Return where the IRELATIVE relocations should go in the PLT
175 rela_irelative(Symbol_table*, Layout*);
177 // Return whether we created a section for IRELATIVE relocations.
179 has_irelative_section() const
180 { return this->irelative_rel_ != NULL; }
182 // Return the number of PLT entries.
185 { return this->count_ + this->irelative_count_; }
187 // Return the offset of the first non-reserved PLT entry.
189 first_plt_entry_offset()
190 { return this->get_plt_entry_size(); }
192 // Return the size of a PLT entry.
194 get_plt_entry_size() const
195 { return this->do_get_plt_entry_size(); }
197 // Reserve a slot in the PLT for an existing symbol in an incremental update.
199 reserve_slot(unsigned int plt_index)
201 this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(),
202 (plt_index + 2) * this->get_plt_entry_size());
205 // Return the PLT address to use for a global symbol.
207 address_for_global(const Symbol*);
209 // Return the PLT address to use for a local symbol.
211 address_for_local(const Relobj*, unsigned int symndx);
213 // Add .eh_frame information for the PLT.
215 add_eh_frame(Layout* layout)
216 { this->do_add_eh_frame(layout); }
219 // Fill in the first PLT entry.
221 fill_first_plt_entry(unsigned char* pov,
222 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
223 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
224 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
226 // Fill in a normal PLT entry. Returns the offset into the entry that
227 // should be the initial GOT slot value.
229 fill_plt_entry(unsigned char* pov,
230 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
231 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
232 unsigned int got_offset,
233 unsigned int plt_offset,
234 unsigned int plt_index)
236 return this->do_fill_plt_entry(pov, got_address, plt_address,
237 got_offset, plt_offset, plt_index);
240 // Fill in the reserved TLSDESC PLT entry.
242 fill_tlsdesc_entry(unsigned char* pov,
243 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
244 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
245 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
246 unsigned int tlsdesc_got_offset,
247 unsigned int plt_offset)
249 this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
250 tlsdesc_got_offset, plt_offset);
254 do_get_plt_entry_size() const = 0;
257 do_fill_first_plt_entry(unsigned char* pov,
258 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
259 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr)
263 do_fill_plt_entry(unsigned char* pov,
264 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
265 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
266 unsigned int got_offset,
267 unsigned int plt_offset,
268 unsigned int plt_index) = 0;
271 do_fill_tlsdesc_entry(unsigned char* pov,
272 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
273 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
274 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
275 unsigned int tlsdesc_got_offset,
276 unsigned int plt_offset) = 0;
279 do_add_eh_frame(Layout* layout) = 0;
282 do_adjust_output_section(Output_section* os);
284 // Write to a map file.
286 do_print_to_mapfile(Mapfile* mapfile) const
287 { mapfile->print_output_data(this, _("** PLT")); }
289 // The CIE of the .eh_frame unwind information for the PLT.
290 static const int plt_eh_frame_cie_size = 16;
291 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
294 // Set the final size.
296 set_final_data_size();
298 // Write out the PLT data.
300 do_write(Output_file*);
302 // The reloc section.
304 // The TLSDESC relocs, if necessary. These must follow the regular
306 Reloc_section* tlsdesc_rel_;
307 // The IRELATIVE relocs, if necessary. These must follow the
308 // regular PLT relocations and the TLSDESC relocations.
309 Reloc_section* irelative_rel_;
311 Output_data_got<64, false>* got_;
312 // The .got.plt section.
313 Output_data_got_plt_x86_64* got_plt_;
314 // The part of the .got.plt section used for IRELATIVE relocs.
315 Output_data_space* got_irelative_;
316 // The number of PLT entries.
318 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
319 // follow the regular PLT entries.
320 unsigned int irelative_count_;
321 // Offset of the reserved TLSDESC_GOT entry when needed.
322 unsigned int tlsdesc_got_offset_;
323 // List of available regions within the section, for incremental
325 Free_list free_list_;
329 class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64<size>
332 Output_data_plt_x86_64_standard(Layout* layout,
333 Output_data_got<64, false>* got,
334 Output_data_got_plt_x86_64* got_plt,
335 Output_data_space* got_irelative)
336 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
337 got, got_plt, got_irelative)
340 Output_data_plt_x86_64_standard(Layout* layout,
341 Output_data_got<64, false>* got,
342 Output_data_got_plt_x86_64* got_plt,
343 Output_data_space* got_irelative,
344 unsigned int plt_count)
345 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
346 got, got_plt, got_irelative,
352 do_get_plt_entry_size() const
353 { return plt_entry_size; }
356 do_add_eh_frame(Layout* layout)
358 layout->add_eh_frame_for_plt(this,
359 this->plt_eh_frame_cie,
360 this->plt_eh_frame_cie_size,
362 plt_eh_frame_fde_size);
366 do_fill_first_plt_entry(unsigned char* pov,
367 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
368 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
371 do_fill_plt_entry(unsigned char* pov,
372 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
373 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
374 unsigned int got_offset,
375 unsigned int plt_offset,
376 unsigned int plt_index);
379 do_fill_tlsdesc_entry(unsigned char* pov,
380 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
381 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
382 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
383 unsigned int tlsdesc_got_offset,
384 unsigned int plt_offset);
387 // The size of an entry in the PLT.
388 static const int plt_entry_size = 16;
390 // The first entry in the PLT.
391 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
392 // procedure linkage table for both programs and shared objects."
393 static const unsigned char first_plt_entry[plt_entry_size];
395 // Other entries in the PLT for an executable.
396 static const unsigned char plt_entry[plt_entry_size];
398 // The reserved TLSDESC entry in the PLT for an executable.
399 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
401 // The .eh_frame unwind information for the PLT.
402 static const int plt_eh_frame_fde_size = 32;
403 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
406 // The x86_64 target class.
408 // http://www.x86-64.org/documentation/abi.pdf
409 // TLS info comes from
410 // http://people.redhat.com/drepper/tls.pdf
411 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
414 class Target_x86_64 : public Sized_target<size, false>
417 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
418 // uses only Elf64_Rela relocation entries with explicit addends."
419 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
421 Target_x86_64(const Target::Target_info* info = &x86_64_info)
422 : Sized_target<size, false>(info),
423 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
424 got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
425 rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
426 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
427 tls_base_symbol_defined_(false)
430 // Hook for a new output section.
432 do_new_output_section(Output_section*) const;
434 // Scan the relocations to look for symbol adjustments.
436 gc_process_relocs(Symbol_table* symtab,
438 Sized_relobj_file<size, false>* object,
439 unsigned int data_shndx,
440 unsigned int sh_type,
441 const unsigned char* prelocs,
443 Output_section* output_section,
444 bool needs_special_offset_handling,
445 size_t local_symbol_count,
446 const unsigned char* plocal_symbols);
448 // Scan the relocations to look for symbol adjustments.
450 scan_relocs(Symbol_table* symtab,
452 Sized_relobj_file<size, false>* object,
453 unsigned int data_shndx,
454 unsigned int sh_type,
455 const unsigned char* prelocs,
457 Output_section* output_section,
458 bool needs_special_offset_handling,
459 size_t local_symbol_count,
460 const unsigned char* plocal_symbols);
462 // Finalize the sections.
464 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
466 // Return the value to use for a dynamic which requires special
469 do_dynsym_value(const Symbol*) const;
471 // Relocate a section.
473 relocate_section(const Relocate_info<size, false>*,
474 unsigned int sh_type,
475 const unsigned char* prelocs,
477 Output_section* output_section,
478 bool needs_special_offset_handling,
480 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
481 section_size_type view_size,
482 const Reloc_symbol_changes*);
484 // Scan the relocs during a relocatable link.
486 scan_relocatable_relocs(Symbol_table* symtab,
488 Sized_relobj_file<size, false>* object,
489 unsigned int data_shndx,
490 unsigned int sh_type,
491 const unsigned char* prelocs,
493 Output_section* output_section,
494 bool needs_special_offset_handling,
495 size_t local_symbol_count,
496 const unsigned char* plocal_symbols,
497 Relocatable_relocs*);
499 // Emit relocations for a section.
502 const Relocate_info<size, false>*,
503 unsigned int sh_type,
504 const unsigned char* prelocs,
506 Output_section* output_section,
507 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
508 const Relocatable_relocs*,
510 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
511 section_size_type view_size,
512 unsigned char* reloc_view,
513 section_size_type reloc_view_size);
515 // Return a string used to fill a code section with nops.
517 do_code_fill(section_size_type length) const;
519 // Return whether SYM is defined by the ABI.
521 do_is_defined_by_abi(const Symbol* sym) const
522 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
524 // Return the symbol index to use for a target specific relocation.
525 // The only target specific relocation is R_X86_64_TLSDESC for a
526 // local symbol, which is an absolute reloc.
528 do_reloc_symbol_index(void*, unsigned int r_type) const
530 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
534 // Return the addend to use for a target specific relocation.
536 do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
538 // Return the PLT section.
540 do_plt_address_for_global(const Symbol* gsym) const
541 { return this->plt_section()->address_for_global(gsym); }
544 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
545 { return this->plt_section()->address_for_local(relobj, symndx); }
547 // This function should be defined in targets that can use relocation
548 // types to determine (implemented in local_reloc_may_be_function_pointer
549 // and global_reloc_may_be_function_pointer)
550 // if a function's pointer is taken. ICF uses this in safe mode to only
551 // fold those functions whose pointer is defintely not taken. For x86_64
552 // pie binaries, safe ICF cannot be done by looking at relocation types.
554 do_can_check_for_function_pointers() const
555 { return !parameters->options().pie(); }
557 // Return the base for a DW_EH_PE_datarel encoding.
559 do_ehframe_datarel_base() const;
561 // Adjust -fsplit-stack code which calls non-split-stack code.
563 do_calls_non_split(Relobj* object, unsigned int shndx,
564 section_offset_type fnoffset, section_size_type fnsize,
565 unsigned char* view, section_size_type view_size,
566 std::string* from, std::string* to) const;
568 // Return the size of the GOT section.
572 gold_assert(this->got_ != NULL);
573 return this->got_->data_size();
576 // Return the number of entries in the GOT.
578 got_entry_count() const
580 if (this->got_ == NULL)
582 return this->got_size() / 8;
585 // Return the number of entries in the PLT.
587 plt_entry_count() const;
589 // Return the offset of the first non-reserved PLT entry.
591 first_plt_entry_offset() const;
593 // Return the size of each PLT entry.
595 plt_entry_size() const;
597 // Create the GOT section for an incremental update.
598 Output_data_got_base*
599 init_got_plt_for_update(Symbol_table* symtab,
601 unsigned int got_count,
602 unsigned int plt_count);
604 // Reserve a GOT entry for a local symbol, and regenerate any
605 // necessary dynamic relocations.
607 reserve_local_got_entry(unsigned int got_index,
608 Sized_relobj<size, false>* obj,
610 unsigned int got_type);
612 // Reserve a GOT entry for a global symbol, and regenerate any
613 // necessary dynamic relocations.
615 reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
616 unsigned int got_type);
618 // Register an existing PLT entry for a global symbol.
620 register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
623 // Force a COPY relocation for a given symbol.
625 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
627 // Apply an incremental relocation.
629 apply_relocation(const Relocate_info<size, false>* relinfo,
630 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
632 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
635 typename elfcpp::Elf_types<size>::Elf_Addr address,
636 section_size_type view_size);
638 // Add a new reloc argument, returning the index in the vector.
640 add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
642 this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
643 return this->tlsdesc_reloc_info_.size() - 1;
646 Output_data_plt_x86_64<size>*
647 make_data_plt(Layout* layout,
648 Output_data_got<64, false>* got,
649 Output_data_got_plt_x86_64* got_plt,
650 Output_data_space* got_irelative)
652 return this->do_make_data_plt(layout, got, got_plt, got_irelative);
655 Output_data_plt_x86_64<size>*
656 make_data_plt(Layout* layout,
657 Output_data_got<64, false>* got,
658 Output_data_got_plt_x86_64* got_plt,
659 Output_data_space* got_irelative,
660 unsigned int plt_count)
662 return this->do_make_data_plt(layout, got, got_plt, got_irelative,
666 virtual Output_data_plt_x86_64<size>*
667 do_make_data_plt(Layout* layout,
668 Output_data_got<64, false>* got,
669 Output_data_got_plt_x86_64* got_plt,
670 Output_data_space* got_irelative)
672 return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
676 virtual Output_data_plt_x86_64<size>*
677 do_make_data_plt(Layout* layout,
678 Output_data_got<64, false>* got,
679 Output_data_got_plt_x86_64* got_plt,
680 Output_data_space* got_irelative,
681 unsigned int plt_count)
683 return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
689 // The class which scans relocations.
694 : issued_non_pic_error_(false)
698 get_reference_flags(unsigned int r_type);
701 local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
702 Sized_relobj_file<size, false>* object,
703 unsigned int data_shndx,
704 Output_section* output_section,
705 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
706 const elfcpp::Sym<size, false>& lsym,
710 global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
711 Sized_relobj_file<size, false>* object,
712 unsigned int data_shndx,
713 Output_section* output_section,
714 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
718 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
719 Target_x86_64* target,
720 Sized_relobj_file<size, false>* object,
721 unsigned int data_shndx,
722 Output_section* output_section,
723 const elfcpp::Rela<size, false>& reloc,
725 const elfcpp::Sym<size, false>& lsym);
728 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
729 Target_x86_64* target,
730 Sized_relobj_file<size, false>* object,
731 unsigned int data_shndx,
732 Output_section* output_section,
733 const elfcpp::Rela<size, false>& reloc,
739 unsupported_reloc_local(Sized_relobj_file<size, false>*,
740 unsigned int r_type);
743 unsupported_reloc_global(Sized_relobj_file<size, false>*,
744 unsigned int r_type, Symbol*);
747 check_non_pic(Relobj*, unsigned int r_type, Symbol*);
750 possible_function_pointer_reloc(unsigned int r_type);
753 reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
754 unsigned int r_type);
756 // Whether we have issued an error about a non-PIC compilation.
757 bool issued_non_pic_error_;
760 // The class which implements relocation.
765 : skip_call_tls_get_addr_(false)
770 if (this->skip_call_tls_get_addr_)
772 // FIXME: This needs to specify the location somehow.
773 gold_error(_("missing expected TLS relocation"));
777 // Do a relocation. Return false if the caller should not issue
778 // any warnings about this relocation.
780 relocate(const Relocate_info<size, false>*, Target_x86_64*,
782 size_t relnum, const elfcpp::Rela<size, false>&,
783 unsigned int r_type, const Sized_symbol<size>*,
784 const Symbol_value<size>*,
785 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
789 // Do a TLS relocation.
791 relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
792 size_t relnum, const elfcpp::Rela<size, false>&,
793 unsigned int r_type, const Sized_symbol<size>*,
794 const Symbol_value<size>*,
795 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
798 // Do a TLS General-Dynamic to Initial-Exec transition.
800 tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
801 Output_segment* tls_segment,
802 const elfcpp::Rela<size, false>&, unsigned int r_type,
803 typename elfcpp::Elf_types<size>::Elf_Addr value,
805 typename elfcpp::Elf_types<size>::Elf_Addr,
806 section_size_type view_size);
808 // Do a TLS General-Dynamic to Local-Exec transition.
810 tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
811 Output_segment* tls_segment,
812 const elfcpp::Rela<size, false>&, unsigned int r_type,
813 typename elfcpp::Elf_types<size>::Elf_Addr value,
815 section_size_type view_size);
817 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
819 tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
820 Output_segment* tls_segment,
821 const elfcpp::Rela<size, false>&, unsigned int r_type,
822 typename elfcpp::Elf_types<size>::Elf_Addr value,
824 typename elfcpp::Elf_types<size>::Elf_Addr,
825 section_size_type view_size);
827 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
829 tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
830 Output_segment* tls_segment,
831 const elfcpp::Rela<size, false>&, unsigned int r_type,
832 typename elfcpp::Elf_types<size>::Elf_Addr value,
834 section_size_type view_size);
836 // Do a TLS Local-Dynamic to Local-Exec transition.
838 tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
839 Output_segment* tls_segment,
840 const elfcpp::Rela<size, false>&, unsigned int r_type,
841 typename elfcpp::Elf_types<size>::Elf_Addr value,
843 section_size_type view_size);
845 // Do a TLS Initial-Exec to Local-Exec transition.
847 tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
848 Output_segment* tls_segment,
849 const elfcpp::Rela<size, false>&, unsigned int r_type,
850 typename elfcpp::Elf_types<size>::Elf_Addr value,
852 section_size_type view_size);
854 // This is set if we should skip the next reloc, which should be a
855 // PLT32 reloc against ___tls_get_addr.
856 bool skip_call_tls_get_addr_;
859 // A class which returns the size required for a relocation type,
860 // used while scanning relocs during a relocatable link.
861 class Relocatable_size_for_reloc
865 get_size_for_reloc(unsigned int, Relobj*);
868 // Adjust TLS relocation type based on the options and whether this
869 // is a local symbol.
870 static tls::Tls_optimization
871 optimize_tls_reloc(bool is_final, int r_type);
873 // Get the GOT section, creating it if necessary.
874 Output_data_got<64, false>*
875 got_section(Symbol_table*, Layout*);
877 // Get the GOT PLT section.
878 Output_data_got_plt_x86_64*
879 got_plt_section() const
881 gold_assert(this->got_plt_ != NULL);
882 return this->got_plt_;
885 // Get the GOT section for TLSDESC entries.
886 Output_data_got<64, false>*
887 got_tlsdesc_section() const
889 gold_assert(this->got_tlsdesc_ != NULL);
890 return this->got_tlsdesc_;
893 // Create the PLT section.
895 make_plt_section(Symbol_table* symtab, Layout* layout);
897 // Create a PLT entry for a global symbol.
899 make_plt_entry(Symbol_table*, Layout*, Symbol*);
901 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
903 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
904 Sized_relobj_file<size, false>* relobj,
905 unsigned int local_sym_index);
907 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
909 define_tls_base_symbol(Symbol_table*, Layout*);
911 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
913 reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
915 // Create a GOT entry for the TLS module index.
917 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
918 Sized_relobj_file<size, false>* object);
920 // Get the PLT section.
921 Output_data_plt_x86_64<size>*
924 gold_assert(this->plt_ != NULL);
928 // Get the dynamic reloc section, creating it if necessary.
930 rela_dyn_section(Layout*);
932 // Get the section to use for TLSDESC relocations.
934 rela_tlsdesc_section(Layout*) const;
936 // Get the section to use for IRELATIVE relocations.
938 rela_irelative_section(Layout*);
940 // Add a potential copy relocation.
942 copy_reloc(Symbol_table* symtab, Layout* layout,
943 Sized_relobj_file<size, false>* object,
944 unsigned int shndx, Output_section* output_section,
945 Symbol* sym, const elfcpp::Rela<size, false>& reloc)
947 this->copy_relocs_.copy_reloc(symtab, layout,
948 symtab->get_sized_symbol<size>(sym),
949 object, shndx, output_section,
950 reloc, this->rela_dyn_section(layout));
953 // Information about this specific target which we pass to the
954 // general Target structure.
955 static const Target::Target_info x86_64_info;
957 // The types of GOT entries needed for this platform.
958 // These values are exposed to the ABI in an incremental link.
959 // Do not renumber existing values without changing the version
960 // number of the .gnu_incremental_inputs section.
963 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
964 GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
965 GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
966 GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
969 // This type is used as the argument to the target specific
970 // relocation routines. The only target specific reloc is
971 // R_X86_64_TLSDESC against a local symbol.
974 Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
975 : object(a_object), r_sym(a_r_sym)
978 // The object in which the local symbol is defined.
979 Sized_relobj_file<size, false>* object;
980 // The local symbol index in the object.
985 Output_data_got<64, false>* got_;
987 Output_data_plt_x86_64<size>* plt_;
988 // The GOT PLT section.
989 Output_data_got_plt_x86_64* got_plt_;
990 // The GOT section for IRELATIVE relocations.
991 Output_data_space* got_irelative_;
992 // The GOT section for TLSDESC relocations.
993 Output_data_got<64, false>* got_tlsdesc_;
994 // The _GLOBAL_OFFSET_TABLE_ symbol.
995 Symbol* global_offset_table_;
996 // The dynamic reloc section.
997 Reloc_section* rela_dyn_;
998 // The section to use for IRELATIVE relocs.
999 Reloc_section* rela_irelative_;
1000 // Relocs saved to avoid a COPY reloc.
1001 Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1002 // Offset of the GOT entry for the TLS module index.
1003 unsigned int got_mod_index_offset_;
1004 // We handle R_X86_64_TLSDESC against a local symbol as a target
1005 // specific relocation. Here we store the object and local symbol
1006 // index for the relocation.
1007 std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1008 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1009 bool tls_base_symbol_defined_;
1013 const Target::Target_info Target_x86_64<64>::x86_64_info =
1016 false, // is_big_endian
1017 elfcpp::EM_X86_64, // machine_code
1018 false, // has_make_symbol
1019 false, // has_resolve
1020 true, // has_code_fill
1021 true, // is_default_stack_executable
1022 true, // can_icf_inline_merge_sections
1024 "/lib/ld64.so.1", // program interpreter
1025 0x400000, // default_text_segment_address
1026 0x1000, // abi_pagesize (overridable by -z max-page-size)
1027 0x1000, // common_pagesize (overridable by -z common-page-size)
1028 false, // isolate_execinstr
1030 elfcpp::SHN_UNDEF, // small_common_shndx
1031 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1032 0, // small_common_section_flags
1033 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1034 NULL, // attributes_section
1035 NULL, // attributes_vendor
1036 "_start" // entry_symbol_name
1040 const Target::Target_info Target_x86_64<32>::x86_64_info =
1043 false, // is_big_endian
1044 elfcpp::EM_X86_64, // machine_code
1045 false, // has_make_symbol
1046 false, // has_resolve
1047 true, // has_code_fill
1048 true, // is_default_stack_executable
1049 true, // can_icf_inline_merge_sections
1051 "/libx32/ldx32.so.1", // program interpreter
1052 0x400000, // default_text_segment_address
1053 0x1000, // abi_pagesize (overridable by -z max-page-size)
1054 0x1000, // common_pagesize (overridable by -z common-page-size)
1055 false, // isolate_execinstr
1057 elfcpp::SHN_UNDEF, // small_common_shndx
1058 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1059 0, // small_common_section_flags
1060 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1061 NULL, // attributes_section
1062 NULL, // attributes_vendor
1063 "_start" // entry_symbol_name
1066 // This is called when a new output section is created. This is where
1067 // we handle the SHF_X86_64_LARGE.
1071 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1073 if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1074 os->set_is_large_section();
1077 // Get the GOT section, creating it if necessary.
1080 Output_data_got<64, false>*
1081 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1083 if (this->got_ == NULL)
1085 gold_assert(symtab != NULL && layout != NULL);
1087 // When using -z now, we can treat .got.plt as a relro section.
1088 // Without -z now, it is modified after program startup by lazy
1090 bool is_got_plt_relro = parameters->options().now();
1091 Output_section_order got_order = (is_got_plt_relro
1093 : ORDER_RELRO_LAST);
1094 Output_section_order got_plt_order = (is_got_plt_relro
1096 : ORDER_NON_RELRO_FIRST);
1098 this->got_ = new Output_data_got<64, false>();
1100 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1102 | elfcpp::SHF_WRITE),
1103 this->got_, got_order, true);
1105 this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1106 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1108 | elfcpp::SHF_WRITE),
1109 this->got_plt_, got_plt_order,
1112 // The first three entries are reserved.
1113 this->got_plt_->set_current_data_size(3 * 8);
1115 if (!is_got_plt_relro)
1117 // Those bytes can go into the relro segment.
1118 layout->increase_relro(3 * 8);
1121 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1122 this->global_offset_table_ =
1123 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1124 Symbol_table::PREDEFINED,
1126 0, 0, elfcpp::STT_OBJECT,
1128 elfcpp::STV_HIDDEN, 0,
1131 // If there are any IRELATIVE relocations, they get GOT entries
1132 // in .got.plt after the jump slot entries.
1133 this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1134 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1136 | elfcpp::SHF_WRITE),
1137 this->got_irelative_,
1138 got_plt_order, is_got_plt_relro);
1140 // If there are any TLSDESC relocations, they get GOT entries in
1141 // .got.plt after the jump slot and IRELATIVE entries.
1142 this->got_tlsdesc_ = new Output_data_got<64, false>();
1143 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1145 | elfcpp::SHF_WRITE),
1147 got_plt_order, is_got_plt_relro);
1153 // Get the dynamic reloc section, creating it if necessary.
1156 typename Target_x86_64<size>::Reloc_section*
1157 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1159 if (this->rela_dyn_ == NULL)
1161 gold_assert(layout != NULL);
1162 this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1163 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1164 elfcpp::SHF_ALLOC, this->rela_dyn_,
1165 ORDER_DYNAMIC_RELOCS, false);
1167 return this->rela_dyn_;
1170 // Get the section to use for IRELATIVE relocs, creating it if
1171 // necessary. These go in .rela.dyn, but only after all other dynamic
1172 // relocations. They need to follow the other dynamic relocations so
1173 // that they can refer to global variables initialized by those
1177 typename Target_x86_64<size>::Reloc_section*
1178 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1180 if (this->rela_irelative_ == NULL)
1182 // Make sure we have already created the dynamic reloc section.
1183 this->rela_dyn_section(layout);
1184 this->rela_irelative_ = new Reloc_section(false);
1185 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1186 elfcpp::SHF_ALLOC, this->rela_irelative_,
1187 ORDER_DYNAMIC_RELOCS, false);
1188 gold_assert(this->rela_dyn_->output_section()
1189 == this->rela_irelative_->output_section());
1191 return this->rela_irelative_;
1194 // Write the first three reserved words of the .got.plt section.
1195 // The remainder of the section is written while writing the PLT
1196 // in Output_data_plt_i386::do_write.
1199 Output_data_got_plt_x86_64::do_write(Output_file* of)
1201 // The first entry in the GOT is the address of the .dynamic section
1202 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1203 // We saved space for them when we created the section in
1204 // Target_x86_64::got_section.
1205 const off_t got_file_offset = this->offset();
1206 gold_assert(this->data_size() >= 24);
1207 unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1208 Output_section* dynamic = this->layout_->dynamic_section();
1209 uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1210 elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1211 memset(got_view + 8, 0, 16);
1212 of->write_output_view(got_file_offset, 24, got_view);
1215 // Initialize the PLT section.
1219 Output_data_plt_x86_64<size>::init(Layout* layout)
1221 this->rel_ = new Reloc_section(false);
1222 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1223 elfcpp::SHF_ALLOC, this->rel_,
1224 ORDER_DYNAMIC_PLT_RELOCS, false);
1229 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1231 os->set_entsize(this->get_plt_entry_size());
1234 // Add an entry to the PLT.
1238 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1241 gold_assert(!gsym->has_plt_offset());
1243 unsigned int plt_index;
1245 section_offset_type got_offset;
1247 unsigned int* pcount;
1248 unsigned int offset;
1249 unsigned int reserved;
1250 Output_section_data_build* got;
1251 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1252 && gsym->can_use_relative_reloc(false))
1254 pcount = &this->irelative_count_;
1257 got = this->got_irelative_;
1261 pcount = &this->count_;
1264 got = this->got_plt_;
1267 if (!this->is_data_size_valid())
1269 // Note that when setting the PLT offset for a non-IRELATIVE
1270 // entry we skip the initial reserved PLT entry.
1271 plt_index = *pcount + offset;
1272 plt_offset = plt_index * this->get_plt_entry_size();
1276 got_offset = (plt_index - offset + reserved) * 8;
1277 gold_assert(got_offset == got->current_data_size());
1279 // Every PLT entry needs a GOT entry which points back to the PLT
1280 // entry (this will be changed by the dynamic linker, normally
1281 // lazily when the function is called).
1282 got->set_current_data_size(got_offset + 8);
1286 // FIXME: This is probably not correct for IRELATIVE relocs.
1288 // For incremental updates, find an available slot.
1289 plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1290 this->get_plt_entry_size(), 0);
1291 if (plt_offset == -1)
1292 gold_fallback(_("out of patch space (PLT);"
1293 " relink with --incremental-full"));
1295 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1296 // can be calculated from the PLT index, adjusting for the three
1297 // reserved entries at the beginning of the GOT.
1298 plt_index = plt_offset / this->get_plt_entry_size() - 1;
1299 got_offset = (plt_index - offset + reserved) * 8;
1302 gsym->set_plt_offset(plt_offset);
1304 // Every PLT entry needs a reloc.
1305 this->add_relocation(symtab, layout, gsym, got_offset);
1307 // Note that we don't need to save the symbol. The contents of the
1308 // PLT are independent of which symbols are used. The symbols only
1309 // appear in the relocations.
1312 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1317 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1318 Symbol_table* symtab,
1320 Sized_relobj_file<size, false>* relobj,
1321 unsigned int local_sym_index)
1323 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1324 ++this->irelative_count_;
1326 section_offset_type got_offset = this->got_irelative_->current_data_size();
1328 // Every PLT entry needs a GOT entry which points back to the PLT
1330 this->got_irelative_->set_current_data_size(got_offset + 8);
1332 // Every PLT entry needs a reloc.
1333 Reloc_section* rela = this->rela_irelative(symtab, layout);
1334 rela->add_symbolless_local_addend(relobj, local_sym_index,
1335 elfcpp::R_X86_64_IRELATIVE,
1336 this->got_irelative_, got_offset, 0);
1341 // Add the relocation for a PLT entry.
1345 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1348 unsigned int got_offset)
1350 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1351 && gsym->can_use_relative_reloc(false))
1353 Reloc_section* rela = this->rela_irelative(symtab, layout);
1354 rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1355 this->got_irelative_, got_offset, 0);
1359 gsym->set_needs_dynsym_entry();
1360 this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1365 // Return where the TLSDESC relocations should go, creating it if
1366 // necessary. These follow the JUMP_SLOT relocations.
1369 typename Output_data_plt_x86_64<size>::Reloc_section*
1370 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1372 if (this->tlsdesc_rel_ == NULL)
1374 this->tlsdesc_rel_ = new Reloc_section(false);
1375 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1376 elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1377 ORDER_DYNAMIC_PLT_RELOCS, false);
1378 gold_assert(this->tlsdesc_rel_->output_section()
1379 == this->rel_->output_section());
1381 return this->tlsdesc_rel_;
1384 // Return where the IRELATIVE relocations should go in the PLT. These
1385 // follow the JUMP_SLOT and the TLSDESC relocations.
1388 typename Output_data_plt_x86_64<size>::Reloc_section*
1389 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1392 if (this->irelative_rel_ == NULL)
1394 // Make sure we have a place for the TLSDESC relocations, in
1395 // case we see any later on.
1396 this->rela_tlsdesc(layout);
1397 this->irelative_rel_ = new Reloc_section(false);
1398 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1399 elfcpp::SHF_ALLOC, this->irelative_rel_,
1400 ORDER_DYNAMIC_PLT_RELOCS, false);
1401 gold_assert(this->irelative_rel_->output_section()
1402 == this->rel_->output_section());
1404 if (parameters->doing_static_link())
1406 // A statically linked executable will only have a .rela.plt
1407 // section to hold R_X86_64_IRELATIVE relocs for
1408 // STT_GNU_IFUNC symbols. The library will use these
1409 // symbols to locate the IRELATIVE relocs at program startup
1411 symtab->define_in_output_data("__rela_iplt_start", NULL,
1412 Symbol_table::PREDEFINED,
1413 this->irelative_rel_, 0, 0,
1414 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1415 elfcpp::STV_HIDDEN, 0, false, true);
1416 symtab->define_in_output_data("__rela_iplt_end", NULL,
1417 Symbol_table::PREDEFINED,
1418 this->irelative_rel_, 0, 0,
1419 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1420 elfcpp::STV_HIDDEN, 0, true, true);
1423 return this->irelative_rel_;
1426 // Return the PLT address to use for a global symbol.
1430 Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
1432 uint64_t offset = 0;
1433 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1434 && gsym->can_use_relative_reloc(false))
1435 offset = (this->count_ + 1) * this->get_plt_entry_size();
1436 return this->address() + offset + gsym->plt_offset();
1439 // Return the PLT address to use for a local symbol. These are always
1440 // IRELATIVE relocs.
1444 Output_data_plt_x86_64<size>::address_for_local(const Relobj* object,
1447 return (this->address()
1448 + (this->count_ + 1) * this->get_plt_entry_size()
1449 + object->local_plt_offset(r_sym));
1452 // Set the final size.
1455 Output_data_plt_x86_64<size>::set_final_data_size()
1457 unsigned int count = this->count_ + this->irelative_count_;
1458 if (this->has_tlsdesc_entry())
1460 this->set_data_size((count + 1) * this->get_plt_entry_size());
1463 // The first entry in the PLT for an executable.
1467 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1469 // From AMD64 ABI Draft 0.98, page 76
1470 0xff, 0x35, // pushq contents of memory address
1471 0, 0, 0, 0, // replaced with address of .got + 8
1472 0xff, 0x25, // jmp indirect
1473 0, 0, 0, 0, // replaced with address of .got + 16
1474 0x90, 0x90, 0x90, 0x90 // noop (x4)
1479 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1481 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1482 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1484 memcpy(pov, first_plt_entry, plt_entry_size);
1485 // We do a jmp relative to the PC at the end of this instruction.
1486 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1488 - (plt_address + 6)));
1489 elfcpp::Swap<32, false>::writeval(pov + 8,
1491 - (plt_address + 12)));
1494 // Subsequent entries in the PLT for an executable.
1498 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1500 // From AMD64 ABI Draft 0.98, page 76
1501 0xff, 0x25, // jmpq indirect
1502 0, 0, 0, 0, // replaced with address of symbol in .got
1503 0x68, // pushq immediate
1504 0, 0, 0, 0, // replaced with offset into relocation table
1505 0xe9, // jmpq relative
1506 0, 0, 0, 0 // replaced with offset to start of .plt
1511 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1513 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1514 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1515 unsigned int got_offset,
1516 unsigned int plt_offset,
1517 unsigned int plt_index)
1519 // Check PC-relative offset overflow in PLT entry.
1520 uint64_t plt_got_pcrel_offset = (got_address + got_offset
1521 - (plt_address + plt_offset + 6));
1522 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1523 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1526 memcpy(pov, plt_entry, plt_entry_size);
1527 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1528 plt_got_pcrel_offset);
1530 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1531 elfcpp::Swap<32, false>::writeval(pov + 12,
1532 - (plt_offset + plt_entry_size));
1537 // The reserved TLSDESC entry in the PLT for an executable.
1541 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
1543 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1544 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1545 0xff, 0x35, // pushq x(%rip)
1546 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1547 0xff, 0x25, // jmpq *y(%rip)
1548 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1555 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
1557 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1558 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1559 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
1560 unsigned int tlsdesc_got_offset,
1561 unsigned int plt_offset)
1563 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1564 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1566 - (plt_address + plt_offset
1568 elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1570 + tlsdesc_got_offset
1571 - (plt_address + plt_offset
1575 // The .eh_frame unwind information for the PLT.
1579 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1582 'z', // Augmentation: augmentation size included.
1583 'R', // Augmentation: FDE encoding included.
1584 '\0', // End of augmentation string.
1585 1, // Code alignment factor.
1586 0x78, // Data alignment factor.
1587 16, // Return address column.
1588 1, // Augmentation size.
1589 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1590 | elfcpp::DW_EH_PE_sdata4),
1591 elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1592 elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1593 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1599 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1601 0, 0, 0, 0, // Replaced with offset to .plt.
1602 0, 0, 0, 0, // Replaced with size of .plt.
1603 0, // Augmentation size.
1604 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
1605 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1606 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
1607 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1608 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1609 11, // Block length.
1610 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
1611 elfcpp::DW_OP_breg16, 0, // Push %rip.
1612 elfcpp::DW_OP_lit15, // Push 0xf.
1613 elfcpp::DW_OP_and, // & (%rip & 0xf).
1614 elfcpp::DW_OP_lit11, // Push 0xb.
1615 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
1616 elfcpp::DW_OP_lit3, // Push 3.
1617 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
1618 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1619 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1625 // Write out the PLT. This uses the hand-coded instructions above,
1626 // and adjusts them as needed. This is specified by the AMD64 ABI.
1630 Output_data_plt_x86_64<size>::do_write(Output_file* of)
1632 const off_t offset = this->offset();
1633 const section_size_type oview_size =
1634 convert_to_section_size_type(this->data_size());
1635 unsigned char* const oview = of->get_output_view(offset, oview_size);
1637 const off_t got_file_offset = this->got_plt_->offset();
1638 gold_assert(parameters->incremental_update()
1639 || (got_file_offset + this->got_plt_->data_size()
1640 == this->got_irelative_->offset()));
1641 const section_size_type got_size =
1642 convert_to_section_size_type(this->got_plt_->data_size()
1643 + this->got_irelative_->data_size());
1644 unsigned char* const got_view = of->get_output_view(got_file_offset,
1647 unsigned char* pov = oview;
1649 // The base address of the .plt section.
1650 typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
1651 // The base address of the .got section.
1652 typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
1653 // The base address of the PLT portion of the .got section,
1654 // which is where the GOT pointer will point, and where the
1655 // three reserved GOT entries are located.
1656 typename elfcpp::Elf_types<size>::Elf_Addr got_address
1657 = this->got_plt_->address();
1659 this->fill_first_plt_entry(pov, got_address, plt_address);
1660 pov += this->get_plt_entry_size();
1662 // The first three entries in the GOT are reserved, and are written
1663 // by Output_data_got_plt_x86_64::do_write.
1664 unsigned char* got_pov = got_view + 24;
1666 unsigned int plt_offset = this->get_plt_entry_size();
1667 unsigned int got_offset = 24;
1668 const unsigned int count = this->count_ + this->irelative_count_;
1669 for (unsigned int plt_index = 0;
1672 pov += this->get_plt_entry_size(),
1674 plt_offset += this->get_plt_entry_size(),
1677 // Set and adjust the PLT entry itself.
1678 unsigned int lazy_offset = this->fill_plt_entry(pov,
1679 got_address, plt_address,
1680 got_offset, plt_offset,
1683 // Set the entry in the GOT.
1684 elfcpp::Swap<64, false>::writeval(got_pov,
1685 plt_address + plt_offset + lazy_offset);
1688 if (this->has_tlsdesc_entry())
1690 // Set and adjust the reserved TLSDESC PLT entry.
1691 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1692 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
1693 tlsdesc_got_offset, plt_offset);
1694 pov += this->get_plt_entry_size();
1697 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1698 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1700 of->write_output_view(offset, oview_size, oview);
1701 of->write_output_view(got_file_offset, got_size, got_view);
1704 // Create the PLT section.
1708 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
1710 if (this->plt_ == NULL)
1712 // Create the GOT sections first.
1713 this->got_section(symtab, layout);
1715 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
1716 this->got_irelative_);
1718 // Add unwind information if requested.
1719 if (parameters->options().ld_generated_unwind_info())
1720 this->plt_->add_eh_frame(layout);
1722 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1724 | elfcpp::SHF_EXECINSTR),
1725 this->plt_, ORDER_PLT, false);
1727 // Make the sh_info field of .rela.plt point to .plt.
1728 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1729 rela_plt_os->set_info_section(this->plt_->output_section());
1733 // Return the section for TLSDESC relocations.
1736 typename Target_x86_64<size>::Reloc_section*
1737 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
1739 return this->plt_section()->rela_tlsdesc(layout);
1742 // Create a PLT entry for a global symbol.
1746 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
1749 if (gsym->has_plt_offset())
1752 if (this->plt_ == NULL)
1753 this->make_plt_section(symtab, layout);
1755 this->plt_->add_entry(symtab, layout, gsym);
1758 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1762 Target_x86_64<size>::make_local_ifunc_plt_entry(
1763 Symbol_table* symtab, Layout* layout,
1764 Sized_relobj_file<size, false>* relobj,
1765 unsigned int local_sym_index)
1767 if (relobj->local_has_plt_offset(local_sym_index))
1769 if (this->plt_ == NULL)
1770 this->make_plt_section(symtab, layout);
1771 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1774 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1777 // Return the number of entries in the PLT.
1781 Target_x86_64<size>::plt_entry_count() const
1783 if (this->plt_ == NULL)
1785 return this->plt_->entry_count();
1788 // Return the offset of the first non-reserved PLT entry.
1792 Target_x86_64<size>::first_plt_entry_offset() const
1794 return this->plt_->first_plt_entry_offset();
1797 // Return the size of each PLT entry.
1801 Target_x86_64<size>::plt_entry_size() const
1803 return this->plt_->get_plt_entry_size();
1806 // Create the GOT and PLT sections for an incremental update.
1809 Output_data_got_base*
1810 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
1812 unsigned int got_count,
1813 unsigned int plt_count)
1815 gold_assert(this->got_ == NULL);
1817 this->got_ = new Output_data_got<64, false>(got_count * 8);
1818 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1820 | elfcpp::SHF_WRITE),
1821 this->got_, ORDER_RELRO_LAST,
1824 // Add the three reserved entries.
1825 this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
1826 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1828 | elfcpp::SHF_WRITE),
1829 this->got_plt_, ORDER_NON_RELRO_FIRST,
1832 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1833 this->global_offset_table_ =
1834 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1835 Symbol_table::PREDEFINED,
1837 0, 0, elfcpp::STT_OBJECT,
1839 elfcpp::STV_HIDDEN, 0,
1842 // If there are any TLSDESC relocations, they get GOT entries in
1843 // .got.plt after the jump slot entries.
1844 // FIXME: Get the count for TLSDESC entries.
1845 this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1846 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1847 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1849 ORDER_NON_RELRO_FIRST, false);
1851 // If there are any IRELATIVE relocations, they get GOT entries in
1852 // .got.plt after the jump slot and TLSDESC entries.
1853 this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1854 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1855 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1856 this->got_irelative_,
1857 ORDER_NON_RELRO_FIRST, false);
1859 // Create the PLT section.
1860 this->plt_ = this->make_data_plt(layout, this->got_,
1862 this->got_irelative_,
1865 // Add unwind information if requested.
1866 if (parameters->options().ld_generated_unwind_info())
1867 this->plt_->add_eh_frame(layout);
1869 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1870 elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1871 this->plt_, ORDER_PLT, false);
1873 // Make the sh_info field of .rela.plt point to .plt.
1874 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1875 rela_plt_os->set_info_section(this->plt_->output_section());
1877 // Create the rela_dyn section.
1878 this->rela_dyn_section(layout);
1883 // Reserve a GOT entry for a local symbol, and regenerate any
1884 // necessary dynamic relocations.
1888 Target_x86_64<size>::reserve_local_got_entry(
1889 unsigned int got_index,
1890 Sized_relobj<size, false>* obj,
1892 unsigned int got_type)
1894 unsigned int got_offset = got_index * 8;
1895 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1897 this->got_->reserve_local(got_index, obj, r_sym, got_type);
1900 case GOT_TYPE_STANDARD:
1901 if (parameters->options().output_is_position_independent())
1902 rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1903 this->got_, got_offset, 0, false);
1905 case GOT_TYPE_TLS_OFFSET:
1906 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1907 this->got_, got_offset, 0);
1909 case GOT_TYPE_TLS_PAIR:
1910 this->got_->reserve_slot(got_index + 1);
1911 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1912 this->got_, got_offset, 0);
1914 case GOT_TYPE_TLS_DESC:
1915 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1916 // this->got_->reserve_slot(got_index + 1);
1917 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1918 // this->got_, got_offset, 0);
1925 // Reserve a GOT entry for a global symbol, and regenerate any
1926 // necessary dynamic relocations.
1930 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
1932 unsigned int got_type)
1934 unsigned int got_offset = got_index * 8;
1935 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1937 this->got_->reserve_global(got_index, gsym, got_type);
1940 case GOT_TYPE_STANDARD:
1941 if (!gsym->final_value_is_known())
1943 if (gsym->is_from_dynobj()
1944 || gsym->is_undefined()
1945 || gsym->is_preemptible()
1946 || gsym->type() == elfcpp::STT_GNU_IFUNC)
1947 rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1948 this->got_, got_offset, 0);
1950 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1951 this->got_, got_offset, 0, false);
1954 case GOT_TYPE_TLS_OFFSET:
1955 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1956 this->got_, got_offset, 0, false);
1958 case GOT_TYPE_TLS_PAIR:
1959 this->got_->reserve_slot(got_index + 1);
1960 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1961 this->got_, got_offset, 0, false);
1962 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1963 this->got_, got_offset + 8, 0, false);
1965 case GOT_TYPE_TLS_DESC:
1966 this->got_->reserve_slot(got_index + 1);
1967 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
1968 this->got_, got_offset, 0, false);
1975 // Register an existing PLT entry for a global symbol.
1979 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
1981 unsigned int plt_index,
1984 gold_assert(this->plt_ != NULL);
1985 gold_assert(!gsym->has_plt_offset());
1987 this->plt_->reserve_slot(plt_index);
1989 gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
1991 unsigned int got_offset = (plt_index + 3) * 8;
1992 this->plt_->add_relocation(symtab, layout, gsym, got_offset);
1995 // Force a COPY relocation for a given symbol.
1999 Target_x86_64<size>::emit_copy_reloc(
2000 Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
2002 this->copy_relocs_.emit_copy_reloc(symtab,
2003 symtab->get_sized_symbol<size>(sym),
2006 this->rela_dyn_section(NULL));
2009 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2013 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
2016 if (this->tls_base_symbol_defined_)
2019 Output_segment* tls_segment = layout->tls_segment();
2020 if (tls_segment != NULL)
2022 bool is_exec = parameters->options().output_is_executable();
2023 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
2024 Symbol_table::PREDEFINED,
2028 elfcpp::STV_HIDDEN, 0,
2030 ? Symbol::SEGMENT_END
2031 : Symbol::SEGMENT_START),
2034 this->tls_base_symbol_defined_ = true;
2037 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2041 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
2044 if (this->plt_ == NULL)
2045 this->make_plt_section(symtab, layout);
2047 if (!this->plt_->has_tlsdesc_entry())
2049 // Allocate the TLSDESC_GOT entry.
2050 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2051 unsigned int got_offset = got->add_constant(0);
2053 // Allocate the TLSDESC_PLT entry.
2054 this->plt_->reserve_tlsdesc_entry(got_offset);
2058 // Create a GOT entry for the TLS module index.
2062 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2063 Sized_relobj_file<size, false>* object)
2065 if (this->got_mod_index_offset_ == -1U)
2067 gold_assert(symtab != NULL && layout != NULL && object != NULL);
2068 Reloc_section* rela_dyn = this->rela_dyn_section(layout);
2069 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2070 unsigned int got_offset = got->add_constant(0);
2071 rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
2073 got->add_constant(0);
2074 this->got_mod_index_offset_ = got_offset;
2076 return this->got_mod_index_offset_;
2079 // Optimize the TLS relocation type based on what we know about the
2080 // symbol. IS_FINAL is true if the final address of this symbol is
2081 // known at link time.
2084 tls::Tls_optimization
2085 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
2087 // If we are generating a shared library, then we can't do anything
2089 if (parameters->options().shared())
2090 return tls::TLSOPT_NONE;
2094 case elfcpp::R_X86_64_TLSGD:
2095 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2096 case elfcpp::R_X86_64_TLSDESC_CALL:
2097 // These are General-Dynamic which permits fully general TLS
2098 // access. Since we know that we are generating an executable,
2099 // we can convert this to Initial-Exec. If we also know that
2100 // this is a local symbol, we can further switch to Local-Exec.
2102 return tls::TLSOPT_TO_LE;
2103 return tls::TLSOPT_TO_IE;
2105 case elfcpp::R_X86_64_TLSLD:
2106 // This is Local-Dynamic, which refers to a local symbol in the
2107 // dynamic TLS block. Since we know that we generating an
2108 // executable, we can switch to Local-Exec.
2109 return tls::TLSOPT_TO_LE;
2111 case elfcpp::R_X86_64_DTPOFF32:
2112 case elfcpp::R_X86_64_DTPOFF64:
2113 // Another Local-Dynamic reloc.
2114 return tls::TLSOPT_TO_LE;
2116 case elfcpp::R_X86_64_GOTTPOFF:
2117 // These are Initial-Exec relocs which get the thread offset
2118 // from the GOT. If we know that we are linking against the
2119 // local symbol, we can switch to Local-Exec, which links the
2120 // thread offset into the instruction.
2122 return tls::TLSOPT_TO_LE;
2123 return tls::TLSOPT_NONE;
2125 case elfcpp::R_X86_64_TPOFF32:
2126 // When we already have Local-Exec, there is nothing further we
2128 return tls::TLSOPT_NONE;
2135 // Get the Reference_flags for a particular relocation.
2139 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
2143 case elfcpp::R_X86_64_NONE:
2144 case elfcpp::R_X86_64_GNU_VTINHERIT:
2145 case elfcpp::R_X86_64_GNU_VTENTRY:
2146 case elfcpp::R_X86_64_GOTPC32:
2147 case elfcpp::R_X86_64_GOTPC64:
2148 // No symbol reference.
2151 case elfcpp::R_X86_64_64:
2152 case elfcpp::R_X86_64_32:
2153 case elfcpp::R_X86_64_32S:
2154 case elfcpp::R_X86_64_16:
2155 case elfcpp::R_X86_64_8:
2156 return Symbol::ABSOLUTE_REF;
2158 case elfcpp::R_X86_64_PC64:
2159 case elfcpp::R_X86_64_PC32:
2160 case elfcpp::R_X86_64_PC32_BND:
2161 case elfcpp::R_X86_64_PC16:
2162 case elfcpp::R_X86_64_PC8:
2163 case elfcpp::R_X86_64_GOTOFF64:
2164 return Symbol::RELATIVE_REF;
2166 case elfcpp::R_X86_64_PLT32:
2167 case elfcpp::R_X86_64_PLT32_BND:
2168 case elfcpp::R_X86_64_PLTOFF64:
2169 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
2171 case elfcpp::R_X86_64_GOT64:
2172 case elfcpp::R_X86_64_GOT32:
2173 case elfcpp::R_X86_64_GOTPCREL64:
2174 case elfcpp::R_X86_64_GOTPCREL:
2175 case elfcpp::R_X86_64_GOTPLT64:
2177 return Symbol::ABSOLUTE_REF;
2179 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2180 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2181 case elfcpp::R_X86_64_TLSDESC_CALL:
2182 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2183 case elfcpp::R_X86_64_DTPOFF32:
2184 case elfcpp::R_X86_64_DTPOFF64:
2185 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2186 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2187 return Symbol::TLS_REF;
2189 case elfcpp::R_X86_64_COPY:
2190 case elfcpp::R_X86_64_GLOB_DAT:
2191 case elfcpp::R_X86_64_JUMP_SLOT:
2192 case elfcpp::R_X86_64_RELATIVE:
2193 case elfcpp::R_X86_64_IRELATIVE:
2194 case elfcpp::R_X86_64_TPOFF64:
2195 case elfcpp::R_X86_64_DTPMOD64:
2196 case elfcpp::R_X86_64_TLSDESC:
2197 case elfcpp::R_X86_64_SIZE32:
2198 case elfcpp::R_X86_64_SIZE64:
2200 // Not expected. We will give an error later.
2205 // Report an unsupported relocation against a local symbol.
2209 Target_x86_64<size>::Scan::unsupported_reloc_local(
2210 Sized_relobj_file<size, false>* object,
2211 unsigned int r_type)
2213 gold_error(_("%s: unsupported reloc %u against local symbol"),
2214 object->name().c_str(), r_type);
2217 // We are about to emit a dynamic relocation of type R_TYPE. If the
2218 // dynamic linker does not support it, issue an error. The GNU linker
2219 // only issues a non-PIC error for an allocated read-only section.
2220 // Here we know the section is allocated, but we don't know that it is
2221 // read-only. But we check for all the relocation types which the
2222 // glibc dynamic linker supports, so it seems appropriate to issue an
2223 // error even if the section is not read-only. If GSYM is not NULL,
2224 // it is the symbol the relocation is against; if it is NULL, the
2225 // relocation is against a local symbol.
2229 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
2234 // These are the relocation types supported by glibc for x86_64
2235 // which should always work.
2236 case elfcpp::R_X86_64_RELATIVE:
2237 case elfcpp::R_X86_64_IRELATIVE:
2238 case elfcpp::R_X86_64_GLOB_DAT:
2239 case elfcpp::R_X86_64_JUMP_SLOT:
2240 case elfcpp::R_X86_64_DTPMOD64:
2241 case elfcpp::R_X86_64_DTPOFF64:
2242 case elfcpp::R_X86_64_TPOFF64:
2243 case elfcpp::R_X86_64_64:
2244 case elfcpp::R_X86_64_COPY:
2247 // glibc supports these reloc types, but they can overflow.
2248 case elfcpp::R_X86_64_PC32:
2249 case elfcpp::R_X86_64_PC32_BND:
2250 // A PC relative reference is OK against a local symbol or if
2251 // the symbol is defined locally.
2253 || (!gsym->is_from_dynobj()
2254 && !gsym->is_undefined()
2255 && !gsym->is_preemptible()))
2258 case elfcpp::R_X86_64_32:
2259 // R_X86_64_32 is OK for x32.
2260 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2262 if (this->issued_non_pic_error_)
2264 gold_assert(parameters->options().output_is_position_independent());
2266 object->error(_("requires dynamic R_X86_64_32 reloc which may "
2267 "overflow at runtime; recompile with -fPIC"));
2273 case elfcpp::R_X86_64_32:
2274 r_name = "R_X86_64_32";
2276 case elfcpp::R_X86_64_PC32:
2277 r_name = "R_X86_64_PC32";
2279 case elfcpp::R_X86_64_PC32_BND:
2280 r_name = "R_X86_64_PC32_BND";
2286 object->error(_("requires dynamic %s reloc against '%s' "
2287 "which may overflow at runtime; recompile "
2289 r_name, gsym->name());
2291 this->issued_non_pic_error_ = true;
2295 // This prevents us from issuing more than one error per reloc
2296 // section. But we can still wind up issuing more than one
2297 // error per object file.
2298 if (this->issued_non_pic_error_)
2300 gold_assert(parameters->options().output_is_position_independent());
2301 object->error(_("requires unsupported dynamic reloc %u; "
2302 "recompile with -fPIC"),
2304 this->issued_non_pic_error_ = true;
2307 case elfcpp::R_X86_64_NONE:
2312 // Return whether we need to make a PLT entry for a relocation of the
2313 // given type against a STT_GNU_IFUNC symbol.
2317 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2318 Sized_relobj_file<size, false>* object,
2319 unsigned int r_type)
2321 int flags = Scan::get_reference_flags(r_type);
2322 if (flags & Symbol::TLS_REF)
2323 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2324 object->name().c_str(), r_type);
2328 // Scan a relocation for a local symbol.
2332 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2334 Target_x86_64<size>* target,
2335 Sized_relobj_file<size, false>* object,
2336 unsigned int data_shndx,
2337 Output_section* output_section,
2338 const elfcpp::Rela<size, false>& reloc,
2339 unsigned int r_type,
2340 const elfcpp::Sym<size, false>& lsym,
2346 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2347 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2348 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2350 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2351 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2356 case elfcpp::R_X86_64_NONE:
2357 case elfcpp::R_X86_64_GNU_VTINHERIT:
2358 case elfcpp::R_X86_64_GNU_VTENTRY:
2361 case elfcpp::R_X86_64_64:
2362 // If building a shared library (or a position-independent
2363 // executable), we need to create a dynamic relocation for this
2364 // location. The relocation applied at link time will apply the
2365 // link-time value, so we flag the location with an
2366 // R_X86_64_RELATIVE relocation so the dynamic loader can
2367 // relocate it easily.
2368 if (parameters->options().output_is_position_independent())
2370 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2371 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2372 rela_dyn->add_local_relative(object, r_sym,
2374 ? elfcpp::R_X86_64_RELATIVE64
2375 : elfcpp::R_X86_64_RELATIVE),
2376 output_section, data_shndx,
2377 reloc.get_r_offset(),
2378 reloc.get_r_addend(), is_ifunc);
2382 case elfcpp::R_X86_64_32:
2383 case elfcpp::R_X86_64_32S:
2384 case elfcpp::R_X86_64_16:
2385 case elfcpp::R_X86_64_8:
2386 // If building a shared library (or a position-independent
2387 // executable), we need to create a dynamic relocation for this
2388 // location. We can't use an R_X86_64_RELATIVE relocation
2389 // because that is always a 64-bit relocation.
2390 if (parameters->options().output_is_position_independent())
2392 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2393 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2395 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2396 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2397 rela_dyn->add_local_relative(object, r_sym,
2398 elfcpp::R_X86_64_RELATIVE,
2399 output_section, data_shndx,
2400 reloc.get_r_offset(),
2401 reloc.get_r_addend(), is_ifunc);
2405 this->check_non_pic(object, r_type, NULL);
2407 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2408 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2409 if (lsym.get_st_type() != elfcpp::STT_SECTION)
2410 rela_dyn->add_local(object, r_sym, r_type, output_section,
2411 data_shndx, reloc.get_r_offset(),
2412 reloc.get_r_addend());
2415 gold_assert(lsym.get_st_value() == 0);
2416 unsigned int shndx = lsym.get_st_shndx();
2418 shndx = object->adjust_sym_shndx(r_sym, shndx,
2421 object->error(_("section symbol %u has bad shndx %u"),
2424 rela_dyn->add_local_section(object, shndx,
2425 r_type, output_section,
2426 data_shndx, reloc.get_r_offset(),
2427 reloc.get_r_addend());
2432 case elfcpp::R_X86_64_PC64:
2433 case elfcpp::R_X86_64_PC32:
2434 case elfcpp::R_X86_64_PC32_BND:
2435 case elfcpp::R_X86_64_PC16:
2436 case elfcpp::R_X86_64_PC8:
2439 case elfcpp::R_X86_64_PLT32:
2440 case elfcpp::R_X86_64_PLT32_BND:
2441 // Since we know this is a local symbol, we can handle this as a
2445 case elfcpp::R_X86_64_GOTPC32:
2446 case elfcpp::R_X86_64_GOTOFF64:
2447 case elfcpp::R_X86_64_GOTPC64:
2448 case elfcpp::R_X86_64_PLTOFF64:
2449 // We need a GOT section.
2450 target->got_section(symtab, layout);
2451 // For PLTOFF64, we'd normally want a PLT section, but since we
2452 // know this is a local symbol, no PLT is needed.
2455 case elfcpp::R_X86_64_GOT64:
2456 case elfcpp::R_X86_64_GOT32:
2457 case elfcpp::R_X86_64_GOTPCREL64:
2458 case elfcpp::R_X86_64_GOTPCREL:
2459 case elfcpp::R_X86_64_GOTPLT64:
2461 // The symbol requires a GOT entry.
2462 Output_data_got<64, false>* got = target->got_section(symtab, layout);
2463 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2465 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
2466 // lets function pointers compare correctly with shared
2467 // libraries. Otherwise we would need an IRELATIVE reloc.
2470 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2472 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2475 // If we are generating a shared object, we need to add a
2476 // dynamic relocation for this symbol's GOT entry.
2477 if (parameters->options().output_is_position_independent())
2479 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2480 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2481 if (r_type != elfcpp::R_X86_64_GOT32)
2483 unsigned int got_offset =
2484 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2485 rela_dyn->add_local_relative(object, r_sym,
2486 elfcpp::R_X86_64_RELATIVE,
2487 got, got_offset, 0, is_ifunc);
2491 this->check_non_pic(object, r_type, NULL);
2493 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2494 rela_dyn->add_local(
2495 object, r_sym, r_type, got,
2496 object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2500 // For GOTPLT64, we'd normally want a PLT section, but since
2501 // we know this is a local symbol, no PLT is needed.
2505 case elfcpp::R_X86_64_COPY:
2506 case elfcpp::R_X86_64_GLOB_DAT:
2507 case elfcpp::R_X86_64_JUMP_SLOT:
2508 case elfcpp::R_X86_64_RELATIVE:
2509 case elfcpp::R_X86_64_IRELATIVE:
2510 // These are outstanding tls relocs, which are unexpected when linking
2511 case elfcpp::R_X86_64_TPOFF64:
2512 case elfcpp::R_X86_64_DTPMOD64:
2513 case elfcpp::R_X86_64_TLSDESC:
2514 gold_error(_("%s: unexpected reloc %u in object file"),
2515 object->name().c_str(), r_type);
2518 // These are initial tls relocs, which are expected when linking
2519 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2520 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2521 case elfcpp::R_X86_64_TLSDESC_CALL:
2522 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2523 case elfcpp::R_X86_64_DTPOFF32:
2524 case elfcpp::R_X86_64_DTPOFF64:
2525 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2526 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2528 bool output_is_shared = parameters->options().shared();
2529 const tls::Tls_optimization optimized_type
2530 = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
2534 case elfcpp::R_X86_64_TLSGD: // General-dynamic
2535 if (optimized_type == tls::TLSOPT_NONE)
2537 // Create a pair of GOT entries for the module index and
2538 // dtv-relative offset.
2539 Output_data_got<64, false>* got
2540 = target->got_section(symtab, layout);
2541 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2542 unsigned int shndx = lsym.get_st_shndx();
2544 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2546 object->error(_("local symbol %u has bad shndx %u"),
2549 got->add_local_pair_with_rel(object, r_sym,
2552 target->rela_dyn_section(layout),
2553 elfcpp::R_X86_64_DTPMOD64);
2555 else if (optimized_type != tls::TLSOPT_TO_LE)
2556 unsupported_reloc_local(object, r_type);
2559 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2560 target->define_tls_base_symbol(symtab, layout);
2561 if (optimized_type == tls::TLSOPT_NONE)
2563 // Create reserved PLT and GOT entries for the resolver.
2564 target->reserve_tlsdesc_entries(symtab, layout);
2566 // Generate a double GOT entry with an
2567 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
2568 // is resolved lazily, so the GOT entry needs to be in
2569 // an area in .got.plt, not .got. Call got_section to
2570 // make sure the section has been created.
2571 target->got_section(symtab, layout);
2572 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2573 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2574 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2576 unsigned int got_offset = got->add_constant(0);
2577 got->add_constant(0);
2578 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2580 Reloc_section* rt = target->rela_tlsdesc_section(layout);
2581 // We store the arguments we need in a vector, and
2582 // use the index into the vector as the parameter
2583 // to pass to the target specific routines.
2584 uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2585 void* arg = reinterpret_cast<void*>(intarg);
2586 rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2587 got, got_offset, 0);
2590 else if (optimized_type != tls::TLSOPT_TO_LE)
2591 unsupported_reloc_local(object, r_type);
2594 case elfcpp::R_X86_64_TLSDESC_CALL:
2597 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2598 if (optimized_type == tls::TLSOPT_NONE)
2600 // Create a GOT entry for the module index.
2601 target->got_mod_index_entry(symtab, layout, object);
2603 else if (optimized_type != tls::TLSOPT_TO_LE)
2604 unsupported_reloc_local(object, r_type);
2607 case elfcpp::R_X86_64_DTPOFF32:
2608 case elfcpp::R_X86_64_DTPOFF64:
2611 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2612 layout->set_has_static_tls();
2613 if (optimized_type == tls::TLSOPT_NONE)
2615 // Create a GOT entry for the tp-relative offset.
2616 Output_data_got<64, false>* got
2617 = target->got_section(symtab, layout);
2618 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2619 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
2620 target->rela_dyn_section(layout),
2621 elfcpp::R_X86_64_TPOFF64);
2623 else if (optimized_type != tls::TLSOPT_TO_LE)
2624 unsupported_reloc_local(object, r_type);
2627 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2628 layout->set_has_static_tls();
2629 if (output_is_shared)
2630 unsupported_reloc_local(object, r_type);
2639 case elfcpp::R_X86_64_SIZE32:
2640 case elfcpp::R_X86_64_SIZE64:
2642 gold_error(_("%s: unsupported reloc %u against local symbol"),
2643 object->name().c_str(), r_type);
2649 // Report an unsupported relocation against a global symbol.
2653 Target_x86_64<size>::Scan::unsupported_reloc_global(
2654 Sized_relobj_file<size, false>* object,
2655 unsigned int r_type,
2658 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2659 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2662 // Returns true if this relocation type could be that of a function pointer.
2665 Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
2669 case elfcpp::R_X86_64_64:
2670 case elfcpp::R_X86_64_32:
2671 case elfcpp::R_X86_64_32S:
2672 case elfcpp::R_X86_64_16:
2673 case elfcpp::R_X86_64_8:
2674 case elfcpp::R_X86_64_GOT64:
2675 case elfcpp::R_X86_64_GOT32:
2676 case elfcpp::R_X86_64_GOTPCREL64:
2677 case elfcpp::R_X86_64_GOTPCREL:
2678 case elfcpp::R_X86_64_GOTPLT64:
2686 // For safe ICF, scan a relocation for a local symbol to check if it
2687 // corresponds to a function pointer being taken. In that case mark
2688 // the function whose pointer was taken as not foldable.
2692 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
2695 Target_x86_64<size>* ,
2696 Sized_relobj_file<size, false>* ,
2699 const elfcpp::Rela<size, false>& ,
2700 unsigned int r_type,
2701 const elfcpp::Sym<size, false>&)
2703 // When building a shared library, do not fold any local symbols as it is
2704 // not possible to distinguish pointer taken versus a call by looking at
2705 // the relocation types.
2706 return (parameters->options().shared()
2707 || possible_function_pointer_reloc(r_type));
2710 // For safe ICF, scan a relocation for a global symbol to check if it
2711 // corresponds to a function pointer being taken. In that case mark
2712 // the function whose pointer was taken as not foldable.
2716 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
2719 Target_x86_64<size>* ,
2720 Sized_relobj_file<size, false>* ,
2723 const elfcpp::Rela<size, false>& ,
2724 unsigned int r_type,
2727 // When building a shared library, do not fold symbols whose visibility
2728 // is hidden, internal or protected.
2729 return ((parameters->options().shared()
2730 && (gsym->visibility() == elfcpp::STV_INTERNAL
2731 || gsym->visibility() == elfcpp::STV_PROTECTED
2732 || gsym->visibility() == elfcpp::STV_HIDDEN))
2733 || possible_function_pointer_reloc(r_type));
2736 // Scan a relocation for a global symbol.
2740 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
2742 Target_x86_64<size>* target,
2743 Sized_relobj_file<size, false>* object,
2744 unsigned int data_shndx,
2745 Output_section* output_section,
2746 const elfcpp::Rela<size, false>& reloc,
2747 unsigned int r_type,
2750 // A STT_GNU_IFUNC symbol may require a PLT entry.
2751 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2752 && this->reloc_needs_plt_for_ifunc(object, r_type))
2753 target->make_plt_entry(symtab, layout, gsym);
2757 case elfcpp::R_X86_64_NONE:
2758 case elfcpp::R_X86_64_GNU_VTINHERIT:
2759 case elfcpp::R_X86_64_GNU_VTENTRY:
2762 case elfcpp::R_X86_64_64:
2763 case elfcpp::R_X86_64_32:
2764 case elfcpp::R_X86_64_32S:
2765 case elfcpp::R_X86_64_16:
2766 case elfcpp::R_X86_64_8:
2768 // Make a PLT entry if necessary.
2769 if (gsym->needs_plt_entry())
2771 target->make_plt_entry(symtab, layout, gsym);
2772 // Since this is not a PC-relative relocation, we may be
2773 // taking the address of a function. In that case we need to
2774 // set the entry in the dynamic symbol table to the address of
2776 if (gsym->is_from_dynobj() && !parameters->options().shared())
2777 gsym->set_needs_dynsym_value();
2779 // Make a dynamic relocation if necessary.
2780 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2782 if (!parameters->options().output_is_position_independent()
2783 && gsym->may_need_copy_reloc())
2785 target->copy_reloc(symtab, layout, object,
2786 data_shndx, output_section, gsym, reloc);
2788 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2789 || (size == 32 && r_type == elfcpp::R_X86_64_32))
2790 && gsym->type() == elfcpp::STT_GNU_IFUNC
2791 && gsym->can_use_relative_reloc(false)
2792 && !gsym->is_from_dynobj()
2793 && !gsym->is_undefined()
2794 && !gsym->is_preemptible())
2796 // Use an IRELATIVE reloc for a locally defined
2797 // STT_GNU_IFUNC symbol. This makes a function
2798 // address in a PIE executable match the address in a
2799 // shared library that it links against.
2800 Reloc_section* rela_dyn =
2801 target->rela_irelative_section(layout);
2802 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2803 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2804 output_section, object,
2806 reloc.get_r_offset(),
2807 reloc.get_r_addend());
2809 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2810 || (size == 32 && r_type == elfcpp::R_X86_64_32))
2811 && gsym->can_use_relative_reloc(false))
2813 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2814 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2815 output_section, object,
2817 reloc.get_r_offset(),
2818 reloc.get_r_addend(), false);
2822 this->check_non_pic(object, r_type, gsym);
2823 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2824 rela_dyn->add_global(gsym, r_type, output_section, object,
2825 data_shndx, reloc.get_r_offset(),
2826 reloc.get_r_addend());
2832 case elfcpp::R_X86_64_PC64:
2833 case elfcpp::R_X86_64_PC32:
2834 case elfcpp::R_X86_64_PC32_BND:
2835 case elfcpp::R_X86_64_PC16:
2836 case elfcpp::R_X86_64_PC8:
2838 // Make a PLT entry if necessary.
2839 if (gsym->needs_plt_entry())
2840 target->make_plt_entry(symtab, layout, gsym);
2841 // Make a dynamic relocation if necessary.
2842 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2844 if (parameters->options().output_is_executable()
2845 && gsym->may_need_copy_reloc())
2847 target->copy_reloc(symtab, layout, object,
2848 data_shndx, output_section, gsym, reloc);
2852 this->check_non_pic(object, r_type, gsym);
2853 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2854 rela_dyn->add_global(gsym, r_type, output_section, object,
2855 data_shndx, reloc.get_r_offset(),
2856 reloc.get_r_addend());
2862 case elfcpp::R_X86_64_GOT64:
2863 case elfcpp::R_X86_64_GOT32:
2864 case elfcpp::R_X86_64_GOTPCREL64:
2865 case elfcpp::R_X86_64_GOTPCREL:
2866 case elfcpp::R_X86_64_GOTPLT64:
2868 // The symbol requires a GOT entry.
2869 Output_data_got<64, false>* got = target->got_section(symtab, layout);
2870 if (gsym->final_value_is_known())
2872 // For a STT_GNU_IFUNC symbol we want the PLT address.
2873 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2874 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2876 got->add_global(gsym, GOT_TYPE_STANDARD);
2880 // If this symbol is not fully resolved, we need to add a
2881 // dynamic relocation for it.
2882 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2884 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2886 // 1) The symbol may be defined in some other module.
2888 // 2) We are building a shared library and this is a
2889 // protected symbol; using GLOB_DAT means that the dynamic
2890 // linker can use the address of the PLT in the main
2891 // executable when appropriate so that function address
2892 // comparisons work.
2894 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2895 // code, again so that function address comparisons work.
2896 if (gsym->is_from_dynobj()
2897 || gsym->is_undefined()
2898 || gsym->is_preemptible()
2899 || (gsym->visibility() == elfcpp::STV_PROTECTED
2900 && parameters->options().shared())
2901 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2902 && parameters->options().output_is_position_independent()))
2903 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
2904 elfcpp::R_X86_64_GLOB_DAT);
2907 // For a STT_GNU_IFUNC symbol we want to write the PLT
2908 // offset into the GOT, so that function pointer
2909 // comparisons work correctly.
2911 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2912 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2915 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2916 // Tell the dynamic linker to use the PLT address
2917 // when resolving relocations.
2918 if (gsym->is_from_dynobj()
2919 && !parameters->options().shared())
2920 gsym->set_needs_dynsym_value();
2924 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2925 rela_dyn->add_global_relative(gsym,
2926 elfcpp::R_X86_64_RELATIVE,
2927 got, got_off, 0, false);
2934 case elfcpp::R_X86_64_PLT32:
2935 case elfcpp::R_X86_64_PLT32_BND:
2936 // If the symbol is fully resolved, this is just a PC32 reloc.
2937 // Otherwise we need a PLT entry.
2938 if (gsym->final_value_is_known())
2940 // If building a shared library, we can also skip the PLT entry
2941 // if the symbol is defined in the output file and is protected
2943 if (gsym->is_defined()
2944 && !gsym->is_from_dynobj()
2945 && !gsym->is_preemptible())
2947 target->make_plt_entry(symtab, layout, gsym);
2950 case elfcpp::R_X86_64_GOTPC32:
2951 case elfcpp::R_X86_64_GOTOFF64:
2952 case elfcpp::R_X86_64_GOTPC64:
2953 case elfcpp::R_X86_64_PLTOFF64:
2954 // We need a GOT section.
2955 target->got_section(symtab, layout);
2956 // For PLTOFF64, we also need a PLT entry (but only if the
2957 // symbol is not fully resolved).
2958 if (r_type == elfcpp::R_X86_64_PLTOFF64
2959 && !gsym->final_value_is_known())
2960 target->make_plt_entry(symtab, layout, gsym);
2963 case elfcpp::R_X86_64_COPY:
2964 case elfcpp::R_X86_64_GLOB_DAT:
2965 case elfcpp::R_X86_64_JUMP_SLOT:
2966 case elfcpp::R_X86_64_RELATIVE:
2967 case elfcpp::R_X86_64_IRELATIVE:
2968 // These are outstanding tls relocs, which are unexpected when linking
2969 case elfcpp::R_X86_64_TPOFF64:
2970 case elfcpp::R_X86_64_DTPMOD64:
2971 case elfcpp::R_X86_64_TLSDESC:
2972 gold_error(_("%s: unexpected reloc %u in object file"),
2973 object->name().c_str(), r_type);
2976 // These are initial tls relocs, which are expected for global()
2977 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2978 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2979 case elfcpp::R_X86_64_TLSDESC_CALL:
2980 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2981 case elfcpp::R_X86_64_DTPOFF32:
2982 case elfcpp::R_X86_64_DTPOFF64:
2983 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2984 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2986 const bool is_final = gsym->final_value_is_known();
2987 const tls::Tls_optimization optimized_type
2988 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
2991 case elfcpp::R_X86_64_TLSGD: // General-dynamic
2992 if (optimized_type == tls::TLSOPT_NONE)
2994 // Create a pair of GOT entries for the module index and
2995 // dtv-relative offset.
2996 Output_data_got<64, false>* got
2997 = target->got_section(symtab, layout);
2998 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2999 target->rela_dyn_section(layout),
3000 elfcpp::R_X86_64_DTPMOD64,
3001 elfcpp::R_X86_64_DTPOFF64);
3003 else if (optimized_type == tls::TLSOPT_TO_IE)
3005 // Create a GOT entry for the tp-relative offset.
3006 Output_data_got<64, false>* got
3007 = target->got_section(symtab, layout);
3008 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3009 target->rela_dyn_section(layout),
3010 elfcpp::R_X86_64_TPOFF64);
3012 else if (optimized_type != tls::TLSOPT_TO_LE)
3013 unsupported_reloc_global(object, r_type, gsym);
3016 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3017 target->define_tls_base_symbol(symtab, layout);
3018 if (optimized_type == tls::TLSOPT_NONE)
3020 // Create reserved PLT and GOT entries for the resolver.
3021 target->reserve_tlsdesc_entries(symtab, layout);
3023 // Create a double GOT entry with an R_X86_64_TLSDESC
3024 // reloc. The R_X86_64_TLSDESC reloc is resolved
3025 // lazily, so the GOT entry needs to be in an area in
3026 // .got.plt, not .got. Call got_section to make sure
3027 // the section has been created.
3028 target->got_section(symtab, layout);
3029 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3030 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3031 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
3032 elfcpp::R_X86_64_TLSDESC, 0);
3034 else if (optimized_type == tls::TLSOPT_TO_IE)
3036 // Create a GOT entry for the tp-relative offset.
3037 Output_data_got<64, false>* got
3038 = target->got_section(symtab, layout);
3039 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3040 target->rela_dyn_section(layout),
3041 elfcpp::R_X86_64_TPOFF64);
3043 else if (optimized_type != tls::TLSOPT_TO_LE)
3044 unsupported_reloc_global(object, r_type, gsym);
3047 case elfcpp::R_X86_64_TLSDESC_CALL:
3050 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3051 if (optimized_type == tls::TLSOPT_NONE)
3053 // Create a GOT entry for the module index.
3054 target->got_mod_index_entry(symtab, layout, object);
3056 else if (optimized_type != tls::TLSOPT_TO_LE)
3057 unsupported_reloc_global(object, r_type, gsym);
3060 case elfcpp::R_X86_64_DTPOFF32:
3061 case elfcpp::R_X86_64_DTPOFF64:
3064 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3065 layout->set_has_static_tls();
3066 if (optimized_type == tls::TLSOPT_NONE)
3068 // Create a GOT entry for the tp-relative offset.
3069 Output_data_got<64, false>* got
3070 = target->got_section(symtab, layout);
3071 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3072 target->rela_dyn_section(layout),
3073 elfcpp::R_X86_64_TPOFF64);
3075 else if (optimized_type != tls::TLSOPT_TO_LE)
3076 unsupported_reloc_global(object, r_type, gsym);
3079 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3080 layout->set_has_static_tls();
3081 if (parameters->options().shared())
3082 unsupported_reloc_global(object, r_type, gsym);
3091 case elfcpp::R_X86_64_SIZE32:
3092 case elfcpp::R_X86_64_SIZE64:
3094 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3095 object->name().c_str(), r_type,
3096 gsym->demangled_name().c_str());
3103 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
3105 Sized_relobj_file<size, false>* object,
3106 unsigned int data_shndx,
3107 unsigned int sh_type,
3108 const unsigned char* prelocs,
3110 Output_section* output_section,
3111 bool needs_special_offset_handling,
3112 size_t local_symbol_count,
3113 const unsigned char* plocal_symbols)
3116 if (sh_type == elfcpp::SHT_REL)
3121 gold::gc_process_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
3122 typename Target_x86_64<size>::Scan,
3123 typename Target_x86_64<size>::Relocatable_size_for_reloc>(
3132 needs_special_offset_handling,
3137 // Scan relocations for a section.
3141 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
3143 Sized_relobj_file<size, false>* object,
3144 unsigned int data_shndx,
3145 unsigned int sh_type,
3146 const unsigned char* prelocs,
3148 Output_section* output_section,
3149 bool needs_special_offset_handling,
3150 size_t local_symbol_count,
3151 const unsigned char* plocal_symbols)
3153 if (sh_type == elfcpp::SHT_REL)
3155 gold_error(_("%s: unsupported REL reloc section"),
3156 object->name().c_str());
3160 gold::scan_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
3161 typename Target_x86_64<size>::Scan>(
3170 needs_special_offset_handling,
3175 // Finalize the sections.
3179 Target_x86_64<size>::do_finalize_sections(
3181 const Input_objects*,
3182 Symbol_table* symtab)
3184 const Reloc_section* rel_plt = (this->plt_ == NULL
3186 : this->plt_->rela_plt());
3187 layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
3188 this->rela_dyn_, true, false);
3190 // Fill in some more dynamic tags.
3191 Output_data_dynamic* const odyn = layout->dynamic_data();
3194 if (this->plt_ != NULL
3195 && this->plt_->output_section() != NULL
3196 && this->plt_->has_tlsdesc_entry())
3198 unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
3199 unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
3200 this->got_->finalize_data_size();
3201 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
3202 this->plt_, plt_offset);
3203 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
3204 this->got_, got_offset);
3208 // Emit any relocs we saved in an attempt to avoid generating COPY
3210 if (this->copy_relocs_.any_saved_relocs())
3211 this->copy_relocs_.emit(this->rela_dyn_section(layout));
3213 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3214 // the .got.plt section.
3215 Symbol* sym = this->global_offset_table_;
3218 uint64_t data_size = this->got_plt_->current_data_size();
3219 symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
3222 if (parameters->doing_static_link()
3223 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
3225 // If linking statically, make sure that the __rela_iplt symbols
3226 // were defined if necessary, even if we didn't create a PLT.
3227 static const Define_symbol_in_segment syms[] =
3230 "__rela_iplt_start", // name
3231 elfcpp::PT_LOAD, // segment_type
3232 elfcpp::PF_W, // segment_flags_set
3233 elfcpp::PF(0), // segment_flags_clear
3236 elfcpp::STT_NOTYPE, // type
3237 elfcpp::STB_GLOBAL, // binding
3238 elfcpp::STV_HIDDEN, // visibility
3240 Symbol::SEGMENT_START, // offset_from_base
3244 "__rela_iplt_end", // name
3245 elfcpp::PT_LOAD, // segment_type
3246 elfcpp::PF_W, // segment_flags_set
3247 elfcpp::PF(0), // segment_flags_clear
3250 elfcpp::STT_NOTYPE, // type
3251 elfcpp::STB_GLOBAL, // binding
3252 elfcpp::STV_HIDDEN, // visibility
3254 Symbol::SEGMENT_START, // offset_from_base
3259 symtab->define_symbols(layout, 2, syms,
3260 layout->script_options()->saw_sections_clause());
3264 // Perform a relocation.
3268 Target_x86_64<size>::Relocate::relocate(
3269 const Relocate_info<size, false>* relinfo,
3270 Target_x86_64<size>* target,
3273 const elfcpp::Rela<size, false>& rela,
3274 unsigned int r_type,
3275 const Sized_symbol<size>* gsym,
3276 const Symbol_value<size>* psymval,
3277 unsigned char* view,
3278 typename elfcpp::Elf_types<size>::Elf_Addr address,
3279 section_size_type view_size)
3281 if (this->skip_call_tls_get_addr_)
3283 if ((r_type != elfcpp::R_X86_64_PLT32
3284 && r_type != elfcpp::R_X86_64_PLT32_BND
3285 && r_type != elfcpp::R_X86_64_PC32_BND
3286 && r_type != elfcpp::R_X86_64_PC32)
3288 || strcmp(gsym->name(), "__tls_get_addr") != 0)
3290 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3291 _("missing expected TLS relocation"));
3295 this->skip_call_tls_get_addr_ = false;
3303 const Sized_relobj_file<size, false>* object = relinfo->object;
3305 // Pick the value to use for symbols defined in the PLT.
3306 Symbol_value<size> symval;
3308 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
3310 symval.set_output_value(target->plt_address_for_global(gsym));
3313 else if (gsym == NULL && psymval->is_ifunc_symbol())
3315 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3316 if (object->local_has_plt_offset(r_sym))
3318 symval.set_output_value(target->plt_address_for_local(object, r_sym));
3323 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3325 // Get the GOT offset if needed.
3326 // The GOT pointer points to the end of the GOT section.
3327 // We need to subtract the size of the GOT section to get
3328 // the actual offset to use in the relocation.
3329 bool have_got_offset = false;
3330 // Since the actual offset is always negative, we use signed int to
3331 // support 64-bit GOT relocations.
3335 case elfcpp::R_X86_64_GOT32:
3336 case elfcpp::R_X86_64_GOT64:
3337 case elfcpp::R_X86_64_GOTPLT64:
3338 case elfcpp::R_X86_64_GOTPCREL:
3339 case elfcpp::R_X86_64_GOTPCREL64:
3342 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3343 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3347 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3348 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3349 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3350 - target->got_size());
3352 have_got_offset = true;
3361 case elfcpp::R_X86_64_NONE:
3362 case elfcpp::R_X86_64_GNU_VTINHERIT:
3363 case elfcpp::R_X86_64_GNU_VTENTRY:
3366 case elfcpp::R_X86_64_64:
3367 Relocate_functions<size, false>::rela64(view, object, psymval, addend);
3370 case elfcpp::R_X86_64_PC64:
3371 Relocate_functions<size, false>::pcrela64(view, object, psymval, addend,
3375 case elfcpp::R_X86_64_32:
3376 // FIXME: we need to verify that value + addend fits into 32 bits:
3377 // uint64_t x = value + addend;
3378 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
3379 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
3380 Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3383 case elfcpp::R_X86_64_32S:
3384 // FIXME: we need to verify that value + addend fits into 32 bits:
3385 // int64_t x = value + addend; // note this quantity is signed!
3386 // x == static_cast<int64_t>(static_cast<int32_t>(x))
3387 Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3390 case elfcpp::R_X86_64_PC32:
3391 case elfcpp::R_X86_64_PC32_BND:
3392 Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3396 case elfcpp::R_X86_64_16:
3397 Relocate_functions<size, false>::rela16(view, object, psymval, addend);
3400 case elfcpp::R_X86_64_PC16:
3401 Relocate_functions<size, false>::pcrela16(view, object, psymval, addend,
3405 case elfcpp::R_X86_64_8:
3406 Relocate_functions<size, false>::rela8(view, object, psymval, addend);
3409 case elfcpp::R_X86_64_PC8:
3410 Relocate_functions<size, false>::pcrela8(view, object, psymval, addend,
3414 case elfcpp::R_X86_64_PLT32:
3415 case elfcpp::R_X86_64_PLT32_BND:
3416 gold_assert(gsym == NULL
3417 || gsym->has_plt_offset()
3418 || gsym->final_value_is_known()
3419 || (gsym->is_defined()
3420 && !gsym->is_from_dynobj()
3421 && !gsym->is_preemptible()));
3422 // Note: while this code looks the same as for R_X86_64_PC32, it
3423 // behaves differently because psymval was set to point to
3424 // the PLT entry, rather than the symbol, in Scan::global().
3425 Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3429 case elfcpp::R_X86_64_PLTOFF64:
3432 gold_assert(gsym->has_plt_offset()
3433 || gsym->final_value_is_known());
3434 typename elfcpp::Elf_types<size>::Elf_Addr got_address;
3435 // This is the address of GLOBAL_OFFSET_TABLE.
3436 got_address = target->got_plt_section()->address();
3437 Relocate_functions<size, false>::rela64(view, object, psymval,
3438 addend - got_address);
3442 case elfcpp::R_X86_64_GOT32:
3443 gold_assert(have_got_offset);
3444 Relocate_functions<size, false>::rela32(view, got_offset, addend);
3447 case elfcpp::R_X86_64_GOTPC32:
3450 typename elfcpp::Elf_types<size>::Elf_Addr value;
3451 value = target->got_plt_section()->address();
3452 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3456 case elfcpp::R_X86_64_GOT64:
3457 case elfcpp::R_X86_64_GOTPLT64:
3458 // R_X86_64_GOTPLT64 is obsolete and treated the the same as
3460 gold_assert(have_got_offset);
3461 Relocate_functions<size, false>::rela64(view, got_offset, addend);
3464 case elfcpp::R_X86_64_GOTPC64:
3467 typename elfcpp::Elf_types<size>::Elf_Addr value;
3468 value = target->got_plt_section()->address();
3469 Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3473 case elfcpp::R_X86_64_GOTOFF64:
3475 typename elfcpp::Elf_types<size>::Elf_Addr value;
3476 value = (psymval->value(object, 0)
3477 - target->got_plt_section()->address());
3478 Relocate_functions<size, false>::rela64(view, value, addend);
3482 case elfcpp::R_X86_64_GOTPCREL:
3484 gold_assert(have_got_offset);
3485 typename elfcpp::Elf_types<size>::Elf_Addr value;
3486 value = target->got_plt_section()->address() + got_offset;
3487 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3491 case elfcpp::R_X86_64_GOTPCREL64:
3493 gold_assert(have_got_offset);
3494 typename elfcpp::Elf_types<size>::Elf_Addr value;
3495 value = target->got_plt_section()->address() + got_offset;
3496 Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3500 case elfcpp::R_X86_64_COPY:
3501 case elfcpp::R_X86_64_GLOB_DAT:
3502 case elfcpp::R_X86_64_JUMP_SLOT:
3503 case elfcpp::R_X86_64_RELATIVE:
3504 case elfcpp::R_X86_64_IRELATIVE:
3505 // These are outstanding tls relocs, which are unexpected when linking
3506 case elfcpp::R_X86_64_TPOFF64:
3507 case elfcpp::R_X86_64_DTPMOD64:
3508 case elfcpp::R_X86_64_TLSDESC:
3509 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3510 _("unexpected reloc %u in object file"),
3514 // These are initial tls relocs, which are expected when linking
3515 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3516 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3517 case elfcpp::R_X86_64_TLSDESC_CALL:
3518 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3519 case elfcpp::R_X86_64_DTPOFF32:
3520 case elfcpp::R_X86_64_DTPOFF64:
3521 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3522 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3523 this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3524 view, address, view_size);
3527 case elfcpp::R_X86_64_SIZE32:
3528 case elfcpp::R_X86_64_SIZE64:
3530 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3531 _("unsupported reloc %u"),
3539 // Perform a TLS relocation.
3543 Target_x86_64<size>::Relocate::relocate_tls(
3544 const Relocate_info<size, false>* relinfo,
3545 Target_x86_64<size>* target,
3547 const elfcpp::Rela<size, false>& rela,
3548 unsigned int r_type,
3549 const Sized_symbol<size>* gsym,
3550 const Symbol_value<size>* psymval,
3551 unsigned char* view,
3552 typename elfcpp::Elf_types<size>::Elf_Addr address,
3553 section_size_type view_size)
3555 Output_segment* tls_segment = relinfo->layout->tls_segment();
3557 const Sized_relobj_file<size, false>* object = relinfo->object;
3558 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3559 elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
3560 bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3562 typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
3564 const bool is_final = (gsym == NULL
3565 ? !parameters->options().shared()
3566 : gsym->final_value_is_known());
3567 tls::Tls_optimization optimized_type
3568 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3571 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3572 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3574 // If this code sequence is used in a non-executable section,
3575 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3576 // on the assumption that it's being used by itself in a debug
3577 // section. Therefore, in the unlikely event that the code
3578 // sequence appears in a non-executable section, we simply
3579 // leave it unoptimized.
3580 optimized_type = tls::TLSOPT_NONE;
3582 if (optimized_type == tls::TLSOPT_TO_LE)
3584 if (tls_segment == NULL)
3586 gold_assert(parameters->errors()->error_count() > 0
3587 || issue_undefined_symbol_error(gsym));
3590 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3591 rela, r_type, value, view,
3597 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3598 ? GOT_TYPE_TLS_OFFSET
3599 : GOT_TYPE_TLS_PAIR);
3600 unsigned int got_offset;
3603 gold_assert(gsym->has_got_offset(got_type));
3604 got_offset = gsym->got_offset(got_type) - target->got_size();
3608 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3609 gold_assert(object->local_has_got_offset(r_sym, got_type));
3610 got_offset = (object->local_got_offset(r_sym, got_type)
3611 - target->got_size());
3613 if (optimized_type == tls::TLSOPT_TO_IE)
3615 value = target->got_plt_section()->address() + got_offset;
3616 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
3617 value, view, address, view_size);
3620 else if (optimized_type == tls::TLSOPT_NONE)
3622 // Relocate the field with the offset of the pair of GOT
3624 value = target->got_plt_section()->address() + got_offset;
3625 Relocate_functions<size, false>::pcrela32(view, value, addend,
3630 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3631 _("unsupported reloc %u"), r_type);
3634 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3635 case elfcpp::R_X86_64_TLSDESC_CALL:
3636 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3638 // See above comment for R_X86_64_TLSGD.
3639 optimized_type = tls::TLSOPT_NONE;
3641 if (optimized_type == tls::TLSOPT_TO_LE)
3643 if (tls_segment == NULL)
3645 gold_assert(parameters->errors()->error_count() > 0
3646 || issue_undefined_symbol_error(gsym));
3649 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3650 rela, r_type, value, view,
3656 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3657 ? GOT_TYPE_TLS_OFFSET
3658 : GOT_TYPE_TLS_DESC);
3659 unsigned int got_offset = 0;
3660 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3661 && optimized_type == tls::TLSOPT_NONE)
3663 // We created GOT entries in the .got.tlsdesc portion of
3664 // the .got.plt section, but the offset stored in the
3665 // symbol is the offset within .got.tlsdesc.
3666 got_offset = (target->got_size()
3667 + target->got_plt_section()->data_size());
3671 gold_assert(gsym->has_got_offset(got_type));
3672 got_offset += gsym->got_offset(got_type) - target->got_size();
3676 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3677 gold_assert(object->local_has_got_offset(r_sym, got_type));
3678 got_offset += (object->local_got_offset(r_sym, got_type)
3679 - target->got_size());
3681 if (optimized_type == tls::TLSOPT_TO_IE)
3683 if (tls_segment == NULL)
3685 gold_assert(parameters->errors()->error_count() > 0
3686 || issue_undefined_symbol_error(gsym));
3689 value = target->got_plt_section()->address() + got_offset;
3690 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
3691 rela, r_type, value, view, address,
3695 else if (optimized_type == tls::TLSOPT_NONE)
3697 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3699 // Relocate the field with the offset of the pair of GOT
3701 value = target->got_plt_section()->address() + got_offset;
3702 Relocate_functions<size, false>::pcrela32(view, value, addend,
3708 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3709 _("unsupported reloc %u"), r_type);
3712 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3713 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3715 // See above comment for R_X86_64_TLSGD.
3716 optimized_type = tls::TLSOPT_NONE;
3718 if (optimized_type == tls::TLSOPT_TO_LE)
3720 if (tls_segment == NULL)
3722 gold_assert(parameters->errors()->error_count() > 0
3723 || issue_undefined_symbol_error(gsym));
3726 this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3727 value, view, view_size);
3730 else if (optimized_type == tls::TLSOPT_NONE)
3732 // Relocate the field with the offset of the GOT entry for
3733 // the module index.
3734 unsigned int got_offset;
3735 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3736 - target->got_size());
3737 value = target->got_plt_section()->address() + got_offset;
3738 Relocate_functions<size, false>::pcrela32(view, value, addend,
3742 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3743 _("unsupported reloc %u"), r_type);
3746 case elfcpp::R_X86_64_DTPOFF32:
3747 // This relocation type is used in debugging information.
3748 // In that case we need to not optimize the value. If the
3749 // section is not executable, then we assume we should not
3750 // optimize this reloc. See comments above for R_X86_64_TLSGD,
3751 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3753 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3755 if (tls_segment == NULL)
3757 gold_assert(parameters->errors()->error_count() > 0
3758 || issue_undefined_symbol_error(gsym));
3761 value -= tls_segment->memsz();
3763 Relocate_functions<size, false>::rela32(view, value, addend);
3766 case elfcpp::R_X86_64_DTPOFF64:
3767 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3768 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3770 if (tls_segment == NULL)
3772 gold_assert(parameters->errors()->error_count() > 0
3773 || issue_undefined_symbol_error(gsym));
3776 value -= tls_segment->memsz();
3778 Relocate_functions<size, false>::rela64(view, value, addend);
3781 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3782 if (optimized_type == tls::TLSOPT_TO_LE)
3784 if (tls_segment == NULL)
3786 gold_assert(parameters->errors()->error_count() > 0
3787 || issue_undefined_symbol_error(gsym));
3790 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3792 r_type, value, view,
3796 else if (optimized_type == tls::TLSOPT_NONE)
3798 // Relocate the field with the offset of the GOT entry for
3799 // the tp-relative offset of the symbol.
3800 unsigned int got_offset;
3803 gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
3804 got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
3805 - target->got_size());
3809 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3810 gold_assert(object->local_has_got_offset(r_sym,
3811 GOT_TYPE_TLS_OFFSET));
3812 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
3813 - target->got_size());
3815 value = target->got_plt_section()->address() + got_offset;
3816 Relocate_functions<size, false>::pcrela32(view, value, addend,
3820 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3821 _("unsupported reloc type %u"),
3825 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3826 if (tls_segment == NULL)
3828 gold_assert(parameters->errors()->error_count() > 0
3829 || issue_undefined_symbol_error(gsym));
3832 value -= tls_segment->memsz();
3833 Relocate_functions<size, false>::rela32(view, value, addend);
3838 // Do a relocation in which we convert a TLS General-Dynamic to an
3843 Target_x86_64<size>::Relocate::tls_gd_to_ie(
3844 const Relocate_info<size, false>* relinfo,
3847 const elfcpp::Rela<size, false>& rela,
3849 typename elfcpp::Elf_types<size>::Elf_Addr value,
3850 unsigned char* view,
3851 typename elfcpp::Elf_types<size>::Elf_Addr address,
3852 section_size_type view_size)
3855 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3856 // .word 0x6666; rex64; call __tls_get_addr
3857 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3859 // leaq foo@tlsgd(%rip),%rdi;
3860 // .word 0x6666; rex64; call __tls_get_addr
3861 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
3863 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3864 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3865 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3869 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3871 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3872 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3873 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
3878 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3880 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3881 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
3882 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
3886 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3887 Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
3890 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3892 this->skip_call_tls_get_addr_ = true;
3895 // Do a relocation in which we convert a TLS General-Dynamic to a
3900 Target_x86_64<size>::Relocate::tls_gd_to_le(
3901 const Relocate_info<size, false>* relinfo,
3903 Output_segment* tls_segment,
3904 const elfcpp::Rela<size, false>& rela,
3906 typename elfcpp::Elf_types<size>::Elf_Addr value,
3907 unsigned char* view,
3908 section_size_type view_size)
3911 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3912 // .word 0x6666; rex64; call __tls_get_addr
3913 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
3915 // leaq foo@tlsgd(%rip),%rdi;
3916 // .word 0x6666; rex64; call __tls_get_addr
3917 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
3919 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3920 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3921 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3925 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3927 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3928 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3929 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
3934 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3936 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3937 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
3939 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
3943 value -= tls_segment->memsz();
3944 Relocate_functions<size, false>::rela32(view + 8, value, 0);
3946 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3948 this->skip_call_tls_get_addr_ = true;
3951 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
3955 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
3956 const Relocate_info<size, false>* relinfo,
3959 const elfcpp::Rela<size, false>& rela,
3960 unsigned int r_type,
3961 typename elfcpp::Elf_types<size>::Elf_Addr value,
3962 unsigned char* view,
3963 typename elfcpp::Elf_types<size>::Elf_Addr address,
3964 section_size_type view_size)
3966 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3968 // leaq foo@tlsdesc(%rip), %rax
3969 // ==> movq foo@gottpoff(%rip), %rax
3970 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3971 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3972 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3973 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
3975 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3976 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3980 // call *foo@tlscall(%rax)
3982 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
3983 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
3984 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3985 view[0] == 0xff && view[1] == 0x10);
3991 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
3995 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
3996 const Relocate_info<size, false>* relinfo,
3998 Output_segment* tls_segment,
3999 const elfcpp::Rela<size, false>& rela,
4000 unsigned int r_type,
4001 typename elfcpp::Elf_types<size>::Elf_Addr value,
4002 unsigned char* view,
4003 section_size_type view_size)
4005 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4007 // leaq foo@tlsdesc(%rip), %rax
4008 // ==> movq foo@tpoff, %rax
4009 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4010 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4011 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4012 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4015 value -= tls_segment->memsz();
4016 Relocate_functions<size, false>::rela32(view, value, 0);
4020 // call *foo@tlscall(%rax)
4022 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4023 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4024 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4025 view[0] == 0xff && view[1] == 0x10);
4033 Target_x86_64<size>::Relocate::tls_ld_to_le(
4034 const Relocate_info<size, false>* relinfo,
4037 const elfcpp::Rela<size, false>& rela,
4039 typename elfcpp::Elf_types<size>::Elf_Addr,
4040 unsigned char* view,
4041 section_size_type view_size)
4043 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4045 // ... leq foo@dtpoff(%rax),%reg
4046 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4048 // ... leq foo@dtpoff(%rax),%reg
4049 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4051 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4052 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
4054 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4055 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
4057 tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
4060 memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4062 memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4064 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4066 this->skip_call_tls_get_addr_ = true;
4069 // Do a relocation in which we convert a TLS Initial-Exec to a
4074 Target_x86_64<size>::Relocate::tls_ie_to_le(
4075 const Relocate_info<size, false>* relinfo,
4077 Output_segment* tls_segment,
4078 const elfcpp::Rela<size, false>& rela,
4080 typename elfcpp::Elf_types<size>::Elf_Addr value,
4081 unsigned char* view,
4082 section_size_type view_size)
4084 // We need to examine the opcodes to figure out which instruction we
4087 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4088 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4090 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4091 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4093 unsigned char op1 = view[-3];
4094 unsigned char op2 = view[-2];
4095 unsigned char op3 = view[-1];
4096 unsigned char reg = op3 >> 3;
4103 else if (size == 32 && op1 == 0x44)
4106 view[-1] = 0xc0 | reg;
4110 // Special handling for %rsp.
4113 else if (size == 32 && op1 == 0x44)
4116 view[-1] = 0xc0 | reg;
4123 else if (size == 32 && op1 == 0x44)
4126 view[-1] = 0x80 | reg | (reg << 3);
4129 value -= tls_segment->memsz();
4130 Relocate_functions<size, false>::rela32(view, value, 0);
4133 // Relocate section data.
4137 Target_x86_64<size>::relocate_section(
4138 const Relocate_info<size, false>* relinfo,
4139 unsigned int sh_type,
4140 const unsigned char* prelocs,
4142 Output_section* output_section,
4143 bool needs_special_offset_handling,
4144 unsigned char* view,
4145 typename elfcpp::Elf_types<size>::Elf_Addr address,
4146 section_size_type view_size,
4147 const Reloc_symbol_changes* reloc_symbol_changes)
4149 gold_assert(sh_type == elfcpp::SHT_RELA);
4151 gold::relocate_section<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
4152 typename Target_x86_64<size>::Relocate,
4153 gold::Default_comdat_behavior>(
4159 needs_special_offset_handling,
4163 reloc_symbol_changes);
4166 // Apply an incremental relocation. Incremental relocations always refer
4167 // to global symbols.
4171 Target_x86_64<size>::apply_relocation(
4172 const Relocate_info<size, false>* relinfo,
4173 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
4174 unsigned int r_type,
4175 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
4177 unsigned char* view,
4178 typename elfcpp::Elf_types<size>::Elf_Addr address,
4179 section_size_type view_size)
4181 gold::apply_relocation<size, false, Target_x86_64<size>,
4182 typename Target_x86_64<size>::Relocate>(
4194 // Return the size of a relocation while scanning during a relocatable
4199 Target_x86_64<size>::Relocatable_size_for_reloc::get_size_for_reloc(
4200 unsigned int r_type,
4205 case elfcpp::R_X86_64_NONE:
4206 case elfcpp::R_X86_64_GNU_VTINHERIT:
4207 case elfcpp::R_X86_64_GNU_VTENTRY:
4208 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4209 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4210 case elfcpp::R_X86_64_TLSDESC_CALL:
4211 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4212 case elfcpp::R_X86_64_DTPOFF32:
4213 case elfcpp::R_X86_64_DTPOFF64:
4214 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4215 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4218 case elfcpp::R_X86_64_64:
4219 case elfcpp::R_X86_64_PC64:
4220 case elfcpp::R_X86_64_GOTOFF64:
4221 case elfcpp::R_X86_64_GOTPC64:
4222 case elfcpp::R_X86_64_PLTOFF64:
4223 case elfcpp::R_X86_64_GOT64:
4224 case elfcpp::R_X86_64_GOTPCREL64:
4225 case elfcpp::R_X86_64_GOTPCREL:
4226 case elfcpp::R_X86_64_GOTPLT64:
4229 case elfcpp::R_X86_64_32:
4230 case elfcpp::R_X86_64_32S:
4231 case elfcpp::R_X86_64_PC32:
4232 case elfcpp::R_X86_64_PC32_BND:
4233 case elfcpp::R_X86_64_PLT32:
4234 case elfcpp::R_X86_64_PLT32_BND:
4235 case elfcpp::R_X86_64_GOTPC32:
4236 case elfcpp::R_X86_64_GOT32:
4239 case elfcpp::R_X86_64_16:
4240 case elfcpp::R_X86_64_PC16:
4243 case elfcpp::R_X86_64_8:
4244 case elfcpp::R_X86_64_PC8:
4247 case elfcpp::R_X86_64_COPY:
4248 case elfcpp::R_X86_64_GLOB_DAT:
4249 case elfcpp::R_X86_64_JUMP_SLOT:
4250 case elfcpp::R_X86_64_RELATIVE:
4251 case elfcpp::R_X86_64_IRELATIVE:
4252 // These are outstanding tls relocs, which are unexpected when linking
4253 case elfcpp::R_X86_64_TPOFF64:
4254 case elfcpp::R_X86_64_DTPMOD64:
4255 case elfcpp::R_X86_64_TLSDESC:
4256 object->error(_("unexpected reloc %u in object file"), r_type);
4259 case elfcpp::R_X86_64_SIZE32:
4260 case elfcpp::R_X86_64_SIZE64:
4262 object->error(_("unsupported reloc %u against local symbol"), r_type);
4267 // Scan the relocs during a relocatable link.
4271 Target_x86_64<size>::scan_relocatable_relocs(
4272 Symbol_table* symtab,
4274 Sized_relobj_file<size, false>* object,
4275 unsigned int data_shndx,
4276 unsigned int sh_type,
4277 const unsigned char* prelocs,
4279 Output_section* output_section,
4280 bool needs_special_offset_handling,
4281 size_t local_symbol_count,
4282 const unsigned char* plocal_symbols,
4283 Relocatable_relocs* rr)
4285 gold_assert(sh_type == elfcpp::SHT_RELA);
4287 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
4288 Relocatable_size_for_reloc> Scan_relocatable_relocs;
4290 gold::scan_relocatable_relocs<size, false, elfcpp::SHT_RELA,
4291 Scan_relocatable_relocs>(
4299 needs_special_offset_handling,
4305 // Relocate a section during a relocatable link.
4309 Target_x86_64<size>::relocate_relocs(
4310 const Relocate_info<size, false>* relinfo,
4311 unsigned int sh_type,
4312 const unsigned char* prelocs,
4314 Output_section* output_section,
4315 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
4316 const Relocatable_relocs* rr,
4317 unsigned char* view,
4318 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
4319 section_size_type view_size,
4320 unsigned char* reloc_view,
4321 section_size_type reloc_view_size)
4323 gold_assert(sh_type == elfcpp::SHT_RELA);
4325 gold::relocate_relocs<size, false, elfcpp::SHT_RELA>(
4330 offset_in_output_section,
4339 // Return the value to use for a dynamic which requires special
4340 // treatment. This is how we support equality comparisons of function
4341 // pointers across shared library boundaries, as described in the
4342 // processor specific ABI supplement.
4346 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
4348 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
4349 return this->plt_address_for_global(gsym);
4352 // Return a string used to fill a code section with nops to take up
4353 // the specified length.
4357 Target_x86_64<size>::do_code_fill(section_size_type length) const
4361 // Build a jmpq instruction to skip over the bytes.
4362 unsigned char jmp[5];
4364 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
4365 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
4366 + std::string(length - 5, static_cast<char>(0x90)));
4369 // Nop sequences of various lengths.
4370 const char nop1[1] = { '\x90' }; // nop
4371 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
4372 const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4373 const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
4375 const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
4377 const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
4378 '\x44', '\x00', '\x00' };
4379 const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
4380 '\x00', '\x00', '\x00',
4382 const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
4383 '\x00', '\x00', '\x00',
4385 const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
4386 '\x84', '\x00', '\x00',
4387 '\x00', '\x00', '\x00' };
4388 const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4389 '\x1f', '\x84', '\x00',
4390 '\x00', '\x00', '\x00',
4392 const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
4393 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4394 '\x00', '\x00', '\x00',
4396 const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
4397 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4398 '\x84', '\x00', '\x00',
4399 '\x00', '\x00', '\x00' };
4400 const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4401 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4402 '\x1f', '\x84', '\x00',
4403 '\x00', '\x00', '\x00',
4405 const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4406 '\x66', '\x66', '\x2e', // data16
4407 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4408 '\x00', '\x00', '\x00',
4410 const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4411 '\x66', '\x66', '\x66', // data16; data16
4412 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4413 '\x84', '\x00', '\x00',
4414 '\x00', '\x00', '\x00' };
4416 const char* nops[16] = {
4418 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
4419 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
4422 return std::string(nops[length], length);
4425 // Return the addend to use for a target specific relocation. The
4426 // only target specific relocation is R_X86_64_TLSDESC for a local
4427 // symbol. We want to set the addend is the offset of the local
4428 // symbol in the TLS segment.
4432 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
4435 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
4436 uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
4437 gold_assert(intarg < this->tlsdesc_reloc_info_.size());
4438 const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
4439 const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
4440 gold_assert(psymval->is_tls_symbol());
4441 // The value of a TLS symbol is the offset in the TLS segment.
4442 return psymval->value(ti.object, 0);
4445 // Return the value to use for the base of a DW_EH_PE_datarel offset
4446 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
4447 // assembler can not write out the difference between two labels in
4448 // different sections, so instead of using a pc-relative value they
4449 // use an offset from the GOT.
4453 Target_x86_64<size>::do_ehframe_datarel_base() const
4455 gold_assert(this->global_offset_table_ != NULL);
4456 Symbol* sym = this->global_offset_table_;
4457 Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
4458 return ssym->value();
4461 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4462 // compiled with -fsplit-stack. The function calls non-split-stack
4463 // code. We have to change the function so that it always ensures
4464 // that it has enough stack space to run some random function.
4468 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
4469 section_offset_type fnoffset,
4470 section_size_type fnsize,
4471 unsigned char* view,
4472 section_size_type view_size,
4474 std::string* to) const
4476 // The function starts with a comparison of the stack pointer and a
4477 // field in the TCB. This is followed by a jump.
4480 if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
4483 // We will call __morestack if the carry flag is set after this
4484 // comparison. We turn the comparison into an stc instruction
4486 view[fnoffset] = '\xf9';
4487 this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
4489 // lea NN(%rsp),%r10
4490 // lea NN(%rsp),%r11
4491 else if ((this->match_view(view, view_size, fnoffset,
4492 "\x4c\x8d\x94\x24", 4)
4493 || this->match_view(view, view_size, fnoffset,
4494 "\x4c\x8d\x9c\x24", 4))
4497 // This is loading an offset from the stack pointer for a
4498 // comparison. The offset is negative, so we decrease the
4499 // offset by the amount of space we need for the stack. This
4500 // means we will avoid calling __morestack if there happens to
4501 // be plenty of space on the stack already.
4502 unsigned char* pval = view + fnoffset + 4;
4503 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4504 val -= parameters->options().split_stack_adjust_size();
4505 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4509 if (!object->has_no_split_stack())
4510 object->error(_("failed to match split-stack sequence at "
4511 "section %u offset %0zx"),
4512 shndx, static_cast<size_t>(fnoffset));
4516 // We have to change the function so that it calls
4517 // __morestack_non_split instead of __morestack. The former will
4518 // allocate additional stack space.
4519 *from = "__morestack";
4520 *to = "__morestack_non_split";
4523 // The selector for x86_64 object files. Note this is never instantiated
4524 // directly. It's only used in Target_selector_x86_64_nacl, below.
4527 class Target_selector_x86_64 : public Target_selector_freebsd
4530 Target_selector_x86_64()
4531 : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
4533 ? "elf64-x86-64" : "elf32-x86-64"),
4535 ? "elf64-x86-64-freebsd"
4536 : "elf32-x86-64-freebsd"),
4537 (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
4541 do_instantiate_target()
4542 { return new Target_x86_64<size>(); }
4546 // NaCl variant. It uses different PLT contents.
4549 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
4552 Output_data_plt_x86_64_nacl(Layout* layout,
4553 Output_data_got<64, false>* got,
4554 Output_data_got_plt_x86_64* got_plt,
4555 Output_data_space* got_irelative)
4556 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4557 got, got_plt, got_irelative)
4560 Output_data_plt_x86_64_nacl(Layout* layout,
4561 Output_data_got<64, false>* got,
4562 Output_data_got_plt_x86_64* got_plt,
4563 Output_data_space* got_irelative,
4564 unsigned int plt_count)
4565 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4566 got, got_plt, got_irelative,
4571 virtual unsigned int
4572 do_get_plt_entry_size() const
4573 { return plt_entry_size; }
4576 do_add_eh_frame(Layout* layout)
4578 layout->add_eh_frame_for_plt(this,
4579 this->plt_eh_frame_cie,
4580 this->plt_eh_frame_cie_size,
4582 plt_eh_frame_fde_size);
4586 do_fill_first_plt_entry(unsigned char* pov,
4587 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
4588 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
4590 virtual unsigned int
4591 do_fill_plt_entry(unsigned char* pov,
4592 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4593 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4594 unsigned int got_offset,
4595 unsigned int plt_offset,
4596 unsigned int plt_index);
4599 do_fill_tlsdesc_entry(unsigned char* pov,
4600 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4601 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4602 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4603 unsigned int tlsdesc_got_offset,
4604 unsigned int plt_offset);
4607 // The size of an entry in the PLT.
4608 static const int plt_entry_size = 64;
4610 // The first entry in the PLT.
4611 static const unsigned char first_plt_entry[plt_entry_size];
4613 // Other entries in the PLT for an executable.
4614 static const unsigned char plt_entry[plt_entry_size];
4616 // The reserved TLSDESC entry in the PLT for an executable.
4617 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
4619 // The .eh_frame unwind information for the PLT.
4620 static const int plt_eh_frame_fde_size = 32;
4621 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4625 class Target_x86_64_nacl : public Target_x86_64<size>
4628 Target_x86_64_nacl()
4629 : Target_x86_64<size>(&x86_64_nacl_info)
4632 virtual Output_data_plt_x86_64<size>*
4633 do_make_data_plt(Layout* layout,
4634 Output_data_got<64, false>* got,
4635 Output_data_got_plt_x86_64* got_plt,
4636 Output_data_space* got_irelative)
4638 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4642 virtual Output_data_plt_x86_64<size>*
4643 do_make_data_plt(Layout* layout,
4644 Output_data_got<64, false>* got,
4645 Output_data_got_plt_x86_64* got_plt,
4646 Output_data_space* got_irelative,
4647 unsigned int plt_count)
4649 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4655 do_code_fill(section_size_type length) const;
4658 static const Target::Target_info x86_64_nacl_info;
4662 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
4665 false, // is_big_endian
4666 elfcpp::EM_X86_64, // machine_code
4667 false, // has_make_symbol
4668 false, // has_resolve
4669 true, // has_code_fill
4670 true, // is_default_stack_executable
4671 true, // can_icf_inline_merge_sections
4673 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4674 0x20000, // default_text_segment_address
4675 0x10000, // abi_pagesize (overridable by -z max-page-size)
4676 0x10000, // common_pagesize (overridable by -z common-page-size)
4677 true, // isolate_execinstr
4678 0x10000000, // rosegment_gap
4679 elfcpp::SHN_UNDEF, // small_common_shndx
4680 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
4681 0, // small_common_section_flags
4682 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
4683 NULL, // attributes_section
4684 NULL, // attributes_vendor
4685 "_start" // entry_symbol_name
4689 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
4692 false, // is_big_endian
4693 elfcpp::EM_X86_64, // machine_code
4694 false, // has_make_symbol
4695 false, // has_resolve
4696 true, // has_code_fill
4697 true, // is_default_stack_executable
4698 true, // can_icf_inline_merge_sections
4700 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4701 0x20000, // default_text_segment_address
4702 0x10000, // abi_pagesize (overridable by -z max-page-size)
4703 0x10000, // common_pagesize (overridable by -z common-page-size)
4704 true, // isolate_execinstr
4705 0x10000000, // rosegment_gap
4706 elfcpp::SHN_UNDEF, // small_common_shndx
4707 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
4708 0, // small_common_section_flags
4709 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
4710 NULL, // attributes_section
4711 NULL, // attributes_vendor
4712 "_start" // entry_symbol_name
4715 #define NACLMASK 0xe0 // 32-byte alignment mask.
4717 // The first entry in the PLT.
4721 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
4723 0xff, 0x35, // pushq contents of memory address
4724 0, 0, 0, 0, // replaced with address of .got + 8
4725 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
4726 0, 0, 0, 0, // replaced with address of .got + 16
4727 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4728 0x4d, 0x01, 0xfb, // add %r15, %r11
4729 0x41, 0xff, 0xe3, // jmpq *%r11
4731 // 9-byte nop sequence to pad out to the next 32-byte boundary.
4732 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4734 // 32 bytes of nop to pad out to the standard size
4735 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4736 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4737 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4738 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4739 0x66, // excess data32 prefix
4745 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
4747 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4748 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
4750 memcpy(pov, first_plt_entry, plt_entry_size);
4751 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4753 - (plt_address + 2 + 4)));
4754 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4756 - (plt_address + 9 + 4)));
4759 // Subsequent entries in the PLT.
4763 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
4765 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
4766 0, 0, 0, 0, // replaced with address of symbol in .got
4767 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4768 0x4d, 0x01, 0xfb, // add %r15, %r11
4769 0x41, 0xff, 0xe3, // jmpq *%r11
4771 // 15-byte nop sequence to pad out to the next 32-byte boundary.
4772 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4773 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4775 // Lazy GOT entries point here (32-byte aligned).
4776 0x68, // pushq immediate
4777 0, 0, 0, 0, // replaced with index into relocation table
4778 0xe9, // jmp relative
4779 0, 0, 0, 0, // replaced with offset to start of .plt0
4781 // 22 bytes of nop to pad out to the standard size.
4782 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4783 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4784 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
4789 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
4791 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4792 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4793 unsigned int got_offset,
4794 unsigned int plt_offset,
4795 unsigned int plt_index)
4797 memcpy(pov, plt_entry, plt_entry_size);
4798 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
4799 (got_address + got_offset
4800 - (plt_address + plt_offset
4803 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
4804 elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
4805 - (plt_offset + 38 + 4));
4810 // The reserved TLSDESC entry in the PLT.
4814 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
4816 0xff, 0x35, // pushq x(%rip)
4817 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
4818 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
4819 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
4820 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4821 0x4d, 0x01, 0xfb, // add %r15, %r11
4822 0x41, 0xff, 0xe3, // jmpq *%r11
4824 // 41 bytes of nop to pad out to the standard size.
4825 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4826 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4827 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4828 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4829 0x66, 0x66, // excess data32 prefixes
4830 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4835 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
4837 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4838 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4839 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4840 unsigned int tlsdesc_got_offset,
4841 unsigned int plt_offset)
4843 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
4844 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4846 - (plt_address + plt_offset
4848 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4850 + tlsdesc_got_offset
4851 - (plt_address + plt_offset
4855 // The .eh_frame unwind information for the PLT.
4859 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4861 0, 0, 0, 0, // Replaced with offset to .plt.
4862 0, 0, 0, 0, // Replaced with size of .plt.
4863 0, // Augmentation size.
4864 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
4865 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4866 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
4867 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4868 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4869 13, // Block length.
4870 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
4871 elfcpp::DW_OP_breg16, 0, // Push %rip.
4872 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4873 elfcpp::DW_OP_and, // & (%rip & 0x3f).
4874 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4875 elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25)
4876 elfcpp::DW_OP_lit3, // Push 3.
4877 elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3)
4878 elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
4879 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4883 // Return a string used to fill a code section with nops.
4884 // For NaCl, long NOPs are only valid if they do not cross
4885 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4888 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
4890 return std::string(length, static_cast<char>(0x90));
4893 // The selector for x86_64-nacl object files.
4896 class Target_selector_x86_64_nacl
4897 : public Target_selector_nacl<Target_selector_x86_64<size>,
4898 Target_x86_64_nacl<size> >
4901 Target_selector_x86_64_nacl()
4902 : Target_selector_nacl<Target_selector_x86_64<size>,
4903 Target_x86_64_nacl<size> >("x86-64",
4905 ? "elf64-x86-64-nacl"
4906 : "elf32-x86-64-nacl",
4909 : "elf32_x86_64_nacl")
4913 Target_selector_x86_64_nacl<64> target_selector_x86_64;
4914 Target_selector_x86_64_nacl<32> target_selector_x32;
4916 } // End anonymous namespace.