1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
30 #include "parameters.h"
37 #include "copy-relocs.h"
39 #include "target-reloc.h"
40 #include "target-select.h"
51 // A class to handle the PLT data.
52 // This is an abstract base class that handles most of the linker details
53 // but does not know the actual contents of PLT entries. The derived
54 // classes below fill in those details.
56 class Output_data_plt_i386 : public Output_section_data
59 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
61 Output_data_plt_i386(Layout*, uint64_t addralign,
62 Output_data_space*, Output_data_space*);
64 // Add an entry to the PLT.
66 add_entry(Symbol_table*, Layout*, Symbol* gsym);
68 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
70 add_local_ifunc_entry(Symbol_table*, Layout*,
71 Sized_relobj_file<32, false>* relobj,
72 unsigned int local_sym_index);
74 // Return the .rel.plt section data.
77 { return this->rel_; }
79 // Return where the TLS_DESC relocations should go.
81 rel_tls_desc(Layout*);
83 // Return where the IRELATIVE relocations should go.
85 rel_irelative(Symbol_table*, Layout*);
87 // Return whether we created a section for IRELATIVE relocations.
89 has_irelative_section() const
90 { return this->irelative_rel_ != NULL; }
92 // Return the number of PLT entries.
95 { return this->count_ + this->irelative_count_; }
97 // Return the offset of the first non-reserved PLT entry.
99 first_plt_entry_offset()
100 { return this->get_plt_entry_size(); }
102 // Return the size of a PLT entry.
104 get_plt_entry_size() const
105 { return this->do_get_plt_entry_size(); }
107 // Return the PLT address to use for a global symbol.
109 address_for_global(const Symbol*);
111 // Return the PLT address to use for a local symbol.
113 address_for_local(const Relobj*, unsigned int symndx);
115 // Add .eh_frame information for the PLT.
117 add_eh_frame(Layout* layout)
118 { this->do_add_eh_frame(layout); }
121 // Fill the first PLT entry, given the pointer to the PLT section data
122 // and the runtime address of the GOT.
124 fill_first_plt_entry(unsigned char* pov,
125 elfcpp::Elf_types<32>::Elf_Addr got_address)
126 { this->do_fill_first_plt_entry(pov, got_address); }
128 // Fill a normal PLT entry, given the pointer to the entry's data in the
129 // section, the runtime address of the GOT, the offset into the GOT of
130 // the corresponding slot, the offset into the relocation section of the
131 // corresponding reloc, and the offset of this entry within the whole
132 // PLT. Return the offset from this PLT entry's runtime address that
133 // should be used to compute the initial value of the GOT slot.
135 fill_plt_entry(unsigned char* pov,
136 elfcpp::Elf_types<32>::Elf_Addr got_address,
137 unsigned int got_offset,
138 unsigned int plt_offset,
139 unsigned int plt_rel_offset)
141 return this->do_fill_plt_entry(pov, got_address, got_offset,
142 plt_offset, plt_rel_offset);
146 do_get_plt_entry_size() const = 0;
149 do_fill_first_plt_entry(unsigned char* pov,
150 elfcpp::Elf_types<32>::Elf_Addr got_address) = 0;
153 do_fill_plt_entry(unsigned char* pov,
154 elfcpp::Elf_types<32>::Elf_Addr got_address,
155 unsigned int got_offset,
156 unsigned int plt_offset,
157 unsigned int plt_rel_offset) = 0;
160 do_add_eh_frame(Layout*) = 0;
163 do_adjust_output_section(Output_section* os);
165 // Write to a map file.
167 do_print_to_mapfile(Mapfile* mapfile) const
168 { mapfile->print_output_data(this, _("** PLT")); }
170 // The .eh_frame unwind information for the PLT.
171 // The CIE is common across variants of the PLT format.
172 static const int plt_eh_frame_cie_size = 16;
173 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
176 // Set the final size.
178 set_final_data_size()
180 this->set_data_size((this->count_ + this->irelative_count_ + 1)
181 * this->get_plt_entry_size());
184 // Write out the PLT data.
186 do_write(Output_file*);
188 // We keep a list of global STT_GNU_IFUNC symbols, each with its
189 // offset in the GOT.
193 unsigned int got_offset;
196 // We keep a list of local STT_GNU_IFUNC symbols, each with its
197 // offset in the GOT.
200 Sized_relobj_file<32, false>* object;
201 unsigned int local_sym_index;
202 unsigned int got_offset;
205 // A pointer to the Layout class, so that we can find the .dynamic
206 // section when we write out the GOT PLT section.
208 // The reloc section.
210 // The TLS_DESC relocations, if necessary. These must follow the
211 // regular PLT relocs.
212 Reloc_section* tls_desc_rel_;
213 // The IRELATIVE relocations, if necessary. These must follow the
214 // regular relocatoins and the TLS_DESC relocations.
215 Reloc_section* irelative_rel_;
216 // The .got.plt section.
217 Output_data_space* got_plt_;
218 // The part of the .got.plt section used for IRELATIVE relocs.
219 Output_data_space* got_irelative_;
220 // The number of PLT entries.
222 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
223 // the regular PLT entries.
224 unsigned int irelative_count_;
225 // Global STT_GNU_IFUNC symbols.
226 std::vector<Global_ifunc> global_ifuncs_;
227 // Local STT_GNU_IFUNC symbols.
228 std::vector<Local_ifunc> local_ifuncs_;
231 // This is an abstract class for the standard PLT layout.
232 // The derived classes below handle the actual PLT contents
233 // for the executable (non-PIC) and shared-library (PIC) cases.
234 // The unwind information is uniform across those two, so it's here.
236 class Output_data_plt_i386_standard : public Output_data_plt_i386
239 Output_data_plt_i386_standard(Layout* layout,
240 Output_data_space* got_plt,
241 Output_data_space* got_irelative)
242 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
247 do_get_plt_entry_size() const
248 { return plt_entry_size; }
251 do_add_eh_frame(Layout* layout)
253 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
254 plt_eh_frame_fde, plt_eh_frame_fde_size);
257 // The size of an entry in the PLT.
258 static const int plt_entry_size = 16;
260 // The .eh_frame unwind information for the PLT.
261 static const int plt_eh_frame_fde_size = 32;
262 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
265 // Actually fill the PLT contents for an executable (non-PIC).
267 class Output_data_plt_i386_exec : public Output_data_plt_i386_standard
270 Output_data_plt_i386_exec(Layout* layout,
271 Output_data_space* got_plt,
272 Output_data_space* got_irelative)
273 : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
278 do_fill_first_plt_entry(unsigned char* pov,
279 elfcpp::Elf_types<32>::Elf_Addr got_address);
282 do_fill_plt_entry(unsigned char* pov,
283 elfcpp::Elf_types<32>::Elf_Addr got_address,
284 unsigned int got_offset,
285 unsigned int plt_offset,
286 unsigned int plt_rel_offset);
289 // The first entry in the PLT for an executable.
290 static const unsigned char first_plt_entry[plt_entry_size];
292 // Other entries in the PLT for an executable.
293 static const unsigned char plt_entry[plt_entry_size];
296 // Actually fill the PLT contents for a shared library (PIC).
298 class Output_data_plt_i386_dyn : public Output_data_plt_i386_standard
301 Output_data_plt_i386_dyn(Layout* layout,
302 Output_data_space* got_plt,
303 Output_data_space* got_irelative)
304 : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
309 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
312 do_fill_plt_entry(unsigned char* pov,
313 elfcpp::Elf_types<32>::Elf_Addr,
314 unsigned int got_offset,
315 unsigned int plt_offset,
316 unsigned int plt_rel_offset);
319 // The first entry in the PLT for a shared object.
320 static const unsigned char first_plt_entry[plt_entry_size];
322 // Other entries in the PLT for a shared object.
323 static const unsigned char plt_entry[plt_entry_size];
326 // The i386 target class.
327 // TLS info comes from
328 // http://people.redhat.com/drepper/tls.pdf
329 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
331 class Target_i386 : public Sized_target<32, false>
334 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
336 Target_i386(const Target::Target_info* info = &i386_info)
337 : Sized_target<32, false>(info),
338 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
339 got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
340 rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
341 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
344 // Process the relocations to determine unreferenced sections for
345 // garbage collection.
347 gc_process_relocs(Symbol_table* symtab,
349 Sized_relobj_file<32, false>* object,
350 unsigned int data_shndx,
351 unsigned int sh_type,
352 const unsigned char* prelocs,
354 Output_section* output_section,
355 bool needs_special_offset_handling,
356 size_t local_symbol_count,
357 const unsigned char* plocal_symbols);
359 // Scan the relocations to look for symbol adjustments.
361 scan_relocs(Symbol_table* symtab,
363 Sized_relobj_file<32, false>* object,
364 unsigned int data_shndx,
365 unsigned int sh_type,
366 const unsigned char* prelocs,
368 Output_section* output_section,
369 bool needs_special_offset_handling,
370 size_t local_symbol_count,
371 const unsigned char* plocal_symbols);
373 // Finalize the sections.
375 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
377 // Return the value to use for a dynamic which requires special
380 do_dynsym_value(const Symbol*) const;
382 // Relocate a section.
384 relocate_section(const Relocate_info<32, false>*,
385 unsigned int sh_type,
386 const unsigned char* prelocs,
388 Output_section* output_section,
389 bool needs_special_offset_handling,
391 elfcpp::Elf_types<32>::Elf_Addr view_address,
392 section_size_type view_size,
393 const Reloc_symbol_changes*);
395 // Scan the relocs during a relocatable link.
397 scan_relocatable_relocs(Symbol_table* symtab,
399 Sized_relobj_file<32, false>* object,
400 unsigned int data_shndx,
401 unsigned int sh_type,
402 const unsigned char* prelocs,
404 Output_section* output_section,
405 bool needs_special_offset_handling,
406 size_t local_symbol_count,
407 const unsigned char* plocal_symbols,
408 Relocatable_relocs*);
410 // Emit relocations for a section.
412 relocate_relocs(const Relocate_info<32, false>*,
413 unsigned int sh_type,
414 const unsigned char* prelocs,
416 Output_section* output_section,
417 off_t offset_in_output_section,
418 const Relocatable_relocs*,
420 elfcpp::Elf_types<32>::Elf_Addr view_address,
421 section_size_type view_size,
422 unsigned char* reloc_view,
423 section_size_type reloc_view_size);
425 // Return a string used to fill a code section with nops.
427 do_code_fill(section_size_type length) const;
429 // Return whether SYM is defined by the ABI.
431 do_is_defined_by_abi(const Symbol* sym) const
432 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
434 // Return whether a symbol name implies a local label. The UnixWare
435 // 2.1 cc generates temporary symbols that start with .X, so we
436 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
437 // If so, we should move the .X recognition into
438 // Target::do_is_local_label_name.
440 do_is_local_label_name(const char* name) const
442 if (name[0] == '.' && name[1] == 'X')
444 return Target::do_is_local_label_name(name);
447 // Return the PLT address to use for a global symbol.
449 do_plt_address_for_global(const Symbol* gsym) const
450 { return this->plt_section()->address_for_global(gsym); }
453 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
454 { return this->plt_section()->address_for_local(relobj, symndx); }
456 // We can tell whether we take the address of a function.
458 do_can_check_for_function_pointers() const
461 // Return the base for a DW_EH_PE_datarel encoding.
463 do_ehframe_datarel_base() const;
465 // Return whether SYM is call to a non-split function.
467 do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
469 // Adjust -fsplit-stack code which calls non-split-stack code.
471 do_calls_non_split(Relobj* object, unsigned int shndx,
472 section_offset_type fnoffset, section_size_type fnsize,
473 unsigned char* view, section_size_type view_size,
474 std::string* from, std::string* to) const;
476 // Return the size of the GOT section.
480 gold_assert(this->got_ != NULL);
481 return this->got_->data_size();
484 // Return the number of entries in the GOT.
486 got_entry_count() const
488 if (this->got_ == NULL)
490 return this->got_size() / 4;
493 // Return the number of entries in the PLT.
495 plt_entry_count() const;
497 // Return the offset of the first non-reserved PLT entry.
499 first_plt_entry_offset() const;
501 // Return the size of each PLT entry.
503 plt_entry_size() const;
506 // Instantiate the plt_ member.
507 // This chooses the right PLT flavor for an executable or a shared object.
508 Output_data_plt_i386*
509 make_data_plt(Layout* layout,
510 Output_data_space* got_plt,
511 Output_data_space* got_irelative,
513 { return this->do_make_data_plt(layout, got_plt, got_irelative, dyn); }
515 virtual Output_data_plt_i386*
516 do_make_data_plt(Layout* layout,
517 Output_data_space* got_plt,
518 Output_data_space* got_irelative,
522 return new Output_data_plt_i386_dyn(layout, got_plt, got_irelative);
524 return new Output_data_plt_i386_exec(layout, got_plt, got_irelative);
528 // The class which scans relocations.
533 get_reference_flags(unsigned int r_type);
536 local(Symbol_table* symtab, Layout* layout, Target_i386* target,
537 Sized_relobj_file<32, false>* object,
538 unsigned int data_shndx,
539 Output_section* output_section,
540 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
541 const elfcpp::Sym<32, false>& lsym);
544 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
545 Sized_relobj_file<32, false>* object,
546 unsigned int data_shndx,
547 Output_section* output_section,
548 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
552 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
554 Sized_relobj_file<32, false>* object,
555 unsigned int data_shndx,
556 Output_section* output_section,
557 const elfcpp::Rel<32, false>& reloc,
559 const elfcpp::Sym<32, false>& lsym);
562 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
564 Sized_relobj_file<32, false>* object,
565 unsigned int data_shndx,
566 Output_section* output_section,
567 const elfcpp::Rel<32, false>& reloc,
572 possible_function_pointer_reloc(unsigned int r_type);
575 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
576 unsigned int r_type);
579 unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
582 unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
586 // The class which implements relocation.
591 : skip_call_tls_get_addr_(false),
592 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
597 if (this->skip_call_tls_get_addr_)
599 // FIXME: This needs to specify the location somehow.
600 gold_error(_("missing expected TLS relocation"));
604 // Return whether the static relocation needs to be applied.
606 should_apply_static_reloc(const Sized_symbol<32>* gsym,
609 Output_section* output_section);
611 // Do a relocation. Return false if the caller should not issue
612 // any warnings about this relocation.
614 relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
615 size_t relnum, const elfcpp::Rel<32, false>&,
616 unsigned int r_type, const Sized_symbol<32>*,
617 const Symbol_value<32>*,
618 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
622 // Do a TLS relocation.
624 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
625 size_t relnum, const elfcpp::Rel<32, false>&,
626 unsigned int r_type, const Sized_symbol<32>*,
627 const Symbol_value<32>*,
628 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
631 // Do a TLS General-Dynamic to Initial-Exec transition.
633 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
634 Output_segment* tls_segment,
635 const elfcpp::Rel<32, false>&, unsigned int r_type,
636 elfcpp::Elf_types<32>::Elf_Addr value,
638 section_size_type view_size);
640 // Do a TLS General-Dynamic to Local-Exec transition.
642 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
643 Output_segment* tls_segment,
644 const elfcpp::Rel<32, false>&, unsigned int r_type,
645 elfcpp::Elf_types<32>::Elf_Addr value,
647 section_size_type view_size);
649 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
652 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
653 Output_segment* tls_segment,
654 const elfcpp::Rel<32, false>&, unsigned int r_type,
655 elfcpp::Elf_types<32>::Elf_Addr value,
657 section_size_type view_size);
659 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
662 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
663 Output_segment* tls_segment,
664 const elfcpp::Rel<32, false>&, unsigned int r_type,
665 elfcpp::Elf_types<32>::Elf_Addr value,
667 section_size_type view_size);
669 // Do a TLS Local-Dynamic to Local-Exec transition.
671 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
672 Output_segment* tls_segment,
673 const elfcpp::Rel<32, false>&, unsigned int r_type,
674 elfcpp::Elf_types<32>::Elf_Addr value,
676 section_size_type view_size);
678 // Do a TLS Initial-Exec to Local-Exec transition.
680 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
681 Output_segment* tls_segment,
682 const elfcpp::Rel<32, false>&, unsigned int r_type,
683 elfcpp::Elf_types<32>::Elf_Addr value,
685 section_size_type view_size);
687 // We need to keep track of which type of local dynamic relocation
688 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
689 enum Local_dynamic_type
696 // This is set if we should skip the next reloc, which should be a
697 // PLT32 reloc against ___tls_get_addr.
698 bool skip_call_tls_get_addr_;
699 // The type of local dynamic relocation we have seen in the section
700 // being relocated, if any.
701 Local_dynamic_type local_dynamic_type_;
704 // A class which returns the size required for a relocation type,
705 // used while scanning relocs during a relocatable link.
706 class Relocatable_size_for_reloc
710 get_size_for_reloc(unsigned int, Relobj*);
713 // Adjust TLS relocation type based on the options and whether this
714 // is a local symbol.
715 static tls::Tls_optimization
716 optimize_tls_reloc(bool is_final, int r_type);
718 // Get the GOT section, creating it if necessary.
719 Output_data_got<32, false>*
720 got_section(Symbol_table*, Layout*);
722 // Get the GOT PLT section.
724 got_plt_section() const
726 gold_assert(this->got_plt_ != NULL);
727 return this->got_plt_;
730 // Get the GOT section for TLSDESC entries.
731 Output_data_got<32, false>*
732 got_tlsdesc_section() const
734 gold_assert(this->got_tlsdesc_ != NULL);
735 return this->got_tlsdesc_;
738 // Create the PLT section.
740 make_plt_section(Symbol_table* symtab, Layout* layout);
742 // Create a PLT entry for a global symbol.
744 make_plt_entry(Symbol_table*, Layout*, Symbol*);
746 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
748 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
749 Sized_relobj_file<32, false>* relobj,
750 unsigned int local_sym_index);
752 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
754 define_tls_base_symbol(Symbol_table*, Layout*);
756 // Create a GOT entry for the TLS module index.
758 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
759 Sized_relobj_file<32, false>* object);
761 // Get the PLT section.
762 Output_data_plt_i386*
765 gold_assert(this->plt_ != NULL);
769 // Get the dynamic reloc section, creating it if necessary.
771 rel_dyn_section(Layout*);
773 // Get the section to use for TLS_DESC relocations.
775 rel_tls_desc_section(Layout*) const;
777 // Get the section to use for IRELATIVE relocations.
779 rel_irelative_section(Layout*);
781 // Add a potential copy relocation.
783 copy_reloc(Symbol_table* symtab, Layout* layout,
784 Sized_relobj_file<32, false>* object,
785 unsigned int shndx, Output_section* output_section,
786 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
788 this->copy_relocs_.copy_reloc(symtab, layout,
789 symtab->get_sized_symbol<32>(sym),
790 object, shndx, output_section, reloc,
791 this->rel_dyn_section(layout));
794 // Information about this specific target which we pass to the
795 // general Target structure.
796 static const Target::Target_info i386_info;
798 // The types of GOT entries needed for this platform.
799 // These values are exposed to the ABI in an incremental link.
800 // Do not renumber existing values without changing the version
801 // number of the .gnu_incremental_inputs section.
804 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
805 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
806 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
807 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
808 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
812 Output_data_got<32, false>* got_;
814 Output_data_plt_i386* plt_;
815 // The GOT PLT section.
816 Output_data_space* got_plt_;
817 // The GOT section for IRELATIVE relocations.
818 Output_data_space* got_irelative_;
819 // The GOT section for TLSDESC relocations.
820 Output_data_got<32, false>* got_tlsdesc_;
821 // The _GLOBAL_OFFSET_TABLE_ symbol.
822 Symbol* global_offset_table_;
823 // The dynamic reloc section.
824 Reloc_section* rel_dyn_;
825 // The section to use for IRELATIVE relocs.
826 Reloc_section* rel_irelative_;
827 // Relocs saved to avoid a COPY reloc.
828 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
829 // Space for variables copied with a COPY reloc.
830 Output_data_space* dynbss_;
831 // Offset of the GOT entry for the TLS module index.
832 unsigned int got_mod_index_offset_;
833 // True if the _TLS_MODULE_BASE_ symbol has been defined.
834 bool tls_base_symbol_defined_;
837 const Target::Target_info Target_i386::i386_info =
840 false, // is_big_endian
841 elfcpp::EM_386, // machine_code
842 false, // has_make_symbol
843 false, // has_resolve
844 true, // has_code_fill
845 true, // is_default_stack_executable
846 true, // can_icf_inline_merge_sections
848 "/usr/lib/libc.so.1", // dynamic_linker
849 0x08048000, // default_text_segment_address
850 0x1000, // abi_pagesize (overridable by -z max-page-size)
851 0x1000, // common_pagesize (overridable by -z common-page-size)
852 false, // isolate_execinstr
854 elfcpp::SHN_UNDEF, // small_common_shndx
855 elfcpp::SHN_UNDEF, // large_common_shndx
856 0, // small_common_section_flags
857 0, // large_common_section_flags
858 NULL, // attributes_section
859 NULL // attributes_vendor
862 // Get the GOT section, creating it if necessary.
864 Output_data_got<32, false>*
865 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
867 if (this->got_ == NULL)
869 gold_assert(symtab != NULL && layout != NULL);
871 this->got_ = new Output_data_got<32, false>();
873 // When using -z now, we can treat .got.plt as a relro section.
874 // Without -z now, it is modified after program startup by lazy
876 bool is_got_plt_relro = parameters->options().now();
877 Output_section_order got_order = (is_got_plt_relro
880 Output_section_order got_plt_order = (is_got_plt_relro
882 : ORDER_NON_RELRO_FIRST);
884 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
886 | elfcpp::SHF_WRITE),
887 this->got_, got_order, true);
889 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
890 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
892 | elfcpp::SHF_WRITE),
893 this->got_plt_, got_plt_order,
896 // The first three entries are reserved.
897 this->got_plt_->set_current_data_size(3 * 4);
899 if (!is_got_plt_relro)
901 // Those bytes can go into the relro segment.
902 layout->increase_relro(3 * 4);
905 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
906 this->global_offset_table_ =
907 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
908 Symbol_table::PREDEFINED,
910 0, 0, elfcpp::STT_OBJECT,
912 elfcpp::STV_HIDDEN, 0,
915 // If there are any IRELATIVE relocations, they get GOT entries
916 // in .got.plt after the jump slot relocations.
917 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
918 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
920 | elfcpp::SHF_WRITE),
921 this->got_irelative_,
922 got_plt_order, is_got_plt_relro);
924 // If there are any TLSDESC relocations, they get GOT entries in
925 // .got.plt after the jump slot entries.
926 this->got_tlsdesc_ = new Output_data_got<32, false>();
927 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
929 | elfcpp::SHF_WRITE),
931 got_plt_order, is_got_plt_relro);
937 // Get the dynamic reloc section, creating it if necessary.
939 Target_i386::Reloc_section*
940 Target_i386::rel_dyn_section(Layout* layout)
942 if (this->rel_dyn_ == NULL)
944 gold_assert(layout != NULL);
945 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
946 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
947 elfcpp::SHF_ALLOC, this->rel_dyn_,
948 ORDER_DYNAMIC_RELOCS, false);
950 return this->rel_dyn_;
953 // Get the section to use for IRELATIVE relocs, creating it if
954 // necessary. These go in .rel.dyn, but only after all other dynamic
955 // relocations. They need to follow the other dynamic relocations so
956 // that they can refer to global variables initialized by those
959 Target_i386::Reloc_section*
960 Target_i386::rel_irelative_section(Layout* layout)
962 if (this->rel_irelative_ == NULL)
964 // Make sure we have already create the dynamic reloc section.
965 this->rel_dyn_section(layout);
966 this->rel_irelative_ = new Reloc_section(false);
967 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
968 elfcpp::SHF_ALLOC, this->rel_irelative_,
969 ORDER_DYNAMIC_RELOCS, false);
970 gold_assert(this->rel_dyn_->output_section()
971 == this->rel_irelative_->output_section());
973 return this->rel_irelative_;
976 // Create the PLT section. The ordinary .got section is an argument,
977 // since we need to refer to the start. We also create our own .got
978 // section just for PLT entries.
980 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
982 Output_data_space* got_plt,
983 Output_data_space* got_irelative)
984 : Output_section_data(addralign),
985 layout_(layout), tls_desc_rel_(NULL),
986 irelative_rel_(NULL), got_plt_(got_plt), got_irelative_(got_irelative),
987 count_(0), irelative_count_(0), global_ifuncs_(), local_ifuncs_()
989 this->rel_ = new Reloc_section(false);
990 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
991 elfcpp::SHF_ALLOC, this->rel_,
992 ORDER_DYNAMIC_PLT_RELOCS, false);
996 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
998 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
999 // linker, and so do we.
1003 // Add an entry to the PLT.
1006 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
1009 gold_assert(!gsym->has_plt_offset());
1011 // Every PLT entry needs a reloc.
1012 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1013 && gsym->can_use_relative_reloc(false))
1015 gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
1016 ++this->irelative_count_;
1017 section_offset_type got_offset =
1018 this->got_irelative_->current_data_size();
1019 this->got_irelative_->set_current_data_size(got_offset + 4);
1020 Reloc_section* rel = this->rel_irelative(symtab, layout);
1021 rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
1022 this->got_irelative_, got_offset);
1023 struct Global_ifunc gi;
1025 gi.got_offset = got_offset;
1026 this->global_ifuncs_.push_back(gi);
1030 // When setting the PLT offset we skip the initial reserved PLT
1032 gsym->set_plt_offset((this->count_ + 1) * this->get_plt_entry_size());
1036 section_offset_type got_offset = this->got_plt_->current_data_size();
1038 // Every PLT entry needs a GOT entry which points back to the
1039 // PLT entry (this will be changed by the dynamic linker,
1040 // normally lazily when the function is called).
1041 this->got_plt_->set_current_data_size(got_offset + 4);
1043 gsym->set_needs_dynsym_entry();
1044 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
1048 // Note that we don't need to save the symbol. The contents of the
1049 // PLT are independent of which symbols are used. The symbols only
1050 // appear in the relocations.
1053 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1057 Output_data_plt_i386::add_local_ifunc_entry(
1058 Symbol_table* symtab,
1060 Sized_relobj_file<32, false>* relobj,
1061 unsigned int local_sym_index)
1063 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1064 ++this->irelative_count_;
1066 section_offset_type got_offset = this->got_irelative_->current_data_size();
1068 // Every PLT entry needs a GOT entry which points back to the PLT
1070 this->got_irelative_->set_current_data_size(got_offset + 4);
1072 // Every PLT entry needs a reloc.
1073 Reloc_section* rel = this->rel_irelative(symtab, layout);
1074 rel->add_symbolless_local_addend(relobj, local_sym_index,
1075 elfcpp::R_386_IRELATIVE,
1076 this->got_irelative_, got_offset);
1078 struct Local_ifunc li;
1080 li.local_sym_index = local_sym_index;
1081 li.got_offset = got_offset;
1082 this->local_ifuncs_.push_back(li);
1087 // Return where the TLS_DESC relocations should go, creating it if
1088 // necessary. These follow the JUMP_SLOT relocations.
1090 Output_data_plt_i386::Reloc_section*
1091 Output_data_plt_i386::rel_tls_desc(Layout* layout)
1093 if (this->tls_desc_rel_ == NULL)
1095 this->tls_desc_rel_ = new Reloc_section(false);
1096 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1097 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
1098 ORDER_DYNAMIC_PLT_RELOCS, false);
1099 gold_assert(this->tls_desc_rel_->output_section()
1100 == this->rel_->output_section());
1102 return this->tls_desc_rel_;
1105 // Return where the IRELATIVE relocations should go in the PLT. These
1106 // follow the JUMP_SLOT and TLS_DESC relocations.
1108 Output_data_plt_i386::Reloc_section*
1109 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
1111 if (this->irelative_rel_ == NULL)
1113 // Make sure we have a place for the TLS_DESC relocations, in
1114 // case we see any later on.
1115 this->rel_tls_desc(layout);
1116 this->irelative_rel_ = new Reloc_section(false);
1117 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1118 elfcpp::SHF_ALLOC, this->irelative_rel_,
1119 ORDER_DYNAMIC_PLT_RELOCS, false);
1120 gold_assert(this->irelative_rel_->output_section()
1121 == this->rel_->output_section());
1123 if (parameters->doing_static_link())
1125 // A statically linked executable will only have a .rel.plt
1126 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1127 // symbols. The library will use these symbols to locate
1128 // the IRELATIVE relocs at program startup time.
1129 symtab->define_in_output_data("__rel_iplt_start", NULL,
1130 Symbol_table::PREDEFINED,
1131 this->irelative_rel_, 0, 0,
1132 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1133 elfcpp::STV_HIDDEN, 0, false, true);
1134 symtab->define_in_output_data("__rel_iplt_end", NULL,
1135 Symbol_table::PREDEFINED,
1136 this->irelative_rel_, 0, 0,
1137 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1138 elfcpp::STV_HIDDEN, 0, true, true);
1141 return this->irelative_rel_;
1144 // Return the PLT address to use for a global symbol.
1147 Output_data_plt_i386::address_for_global(const Symbol* gsym)
1149 uint64_t offset = 0;
1150 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1151 && gsym->can_use_relative_reloc(false))
1152 offset = (this->count_ + 1) * this->get_plt_entry_size();
1153 return this->address() + offset;
1156 // Return the PLT address to use for a local symbol. These are always
1157 // IRELATIVE relocs.
1160 Output_data_plt_i386::address_for_local(const Relobj*, unsigned int)
1162 return this->address() + (this->count_ + 1) * this->get_plt_entry_size();
1165 // The first entry in the PLT for an executable.
1167 const unsigned char Output_data_plt_i386_exec::first_plt_entry[plt_entry_size] =
1169 0xff, 0x35, // pushl contents of memory address
1170 0, 0, 0, 0, // replaced with address of .got + 4
1171 0xff, 0x25, // jmp indirect
1172 0, 0, 0, 0, // replaced with address of .got + 8
1173 0, 0, 0, 0 // unused
1177 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1179 elfcpp::Elf_types<32>::Elf_Addr got_address)
1181 memcpy(pov, first_plt_entry, plt_entry_size);
1182 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1183 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1186 // The first entry in the PLT for a shared object.
1188 const unsigned char Output_data_plt_i386_dyn::first_plt_entry[plt_entry_size] =
1190 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1191 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1192 0, 0, 0, 0 // unused
1196 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1198 elfcpp::Elf_types<32>::Elf_Addr)
1200 memcpy(pov, first_plt_entry, plt_entry_size);
1203 // Subsequent entries in the PLT for an executable.
1205 const unsigned char Output_data_plt_i386_exec::plt_entry[plt_entry_size] =
1207 0xff, 0x25, // jmp indirect
1208 0, 0, 0, 0, // replaced with address of symbol in .got
1209 0x68, // pushl immediate
1210 0, 0, 0, 0, // replaced with offset into relocation table
1211 0xe9, // jmp relative
1212 0, 0, 0, 0 // replaced with offset to start of .plt
1216 Output_data_plt_i386_exec::do_fill_plt_entry(
1218 elfcpp::Elf_types<32>::Elf_Addr got_address,
1219 unsigned int got_offset,
1220 unsigned int plt_offset,
1221 unsigned int plt_rel_offset)
1223 memcpy(pov, plt_entry, plt_entry_size);
1224 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1225 got_address + got_offset);
1226 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1227 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1231 // Subsequent entries in the PLT for a shared object.
1233 const unsigned char Output_data_plt_i386_dyn::plt_entry[plt_entry_size] =
1235 0xff, 0xa3, // jmp *offset(%ebx)
1236 0, 0, 0, 0, // replaced with offset of symbol in .got
1237 0x68, // pushl immediate
1238 0, 0, 0, 0, // replaced with offset into relocation table
1239 0xe9, // jmp relative
1240 0, 0, 0, 0 // replaced with offset to start of .plt
1244 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
1245 elfcpp::Elf_types<32>::Elf_Addr,
1246 unsigned int got_offset,
1247 unsigned int plt_offset,
1248 unsigned int plt_rel_offset)
1250 memcpy(pov, plt_entry, plt_entry_size);
1251 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1252 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1253 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1257 // The .eh_frame unwind information for the PLT.
1260 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1263 'z', // Augmentation: augmentation size included.
1264 'R', // Augmentation: FDE encoding included.
1265 '\0', // End of augmentation string.
1266 1, // Code alignment factor.
1267 0x7c, // Data alignment factor.
1268 8, // Return address column.
1269 1, // Augmentation size.
1270 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1271 | elfcpp::DW_EH_PE_sdata4),
1272 elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1273 elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1274 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1279 Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1281 0, 0, 0, 0, // Replaced with offset to .plt.
1282 0, 0, 0, 0, // Replaced with size of .plt.
1283 0, // Augmentation size.
1284 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
1285 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1286 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
1287 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1288 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1289 11, // Block length.
1290 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
1291 elfcpp::DW_OP_breg8, 0, // Push %eip.
1292 elfcpp::DW_OP_lit15, // Push 0xf.
1293 elfcpp::DW_OP_and, // & (%eip & 0xf).
1294 elfcpp::DW_OP_lit11, // Push 0xb.
1295 elfcpp::DW_OP_ge, // >= ((%eip & 0xf) >= 0xb)
1296 elfcpp::DW_OP_lit2, // Push 2.
1297 elfcpp::DW_OP_shl, // << (((%eip & 0xf) >= 0xb) << 2)
1298 elfcpp::DW_OP_plus, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1299 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1305 // Write out the PLT. This uses the hand-coded instructions above,
1306 // and adjusts them as needed. This is all specified by the i386 ELF
1307 // Processor Supplement.
1310 Output_data_plt_i386::do_write(Output_file* of)
1312 const off_t offset = this->offset();
1313 const section_size_type oview_size =
1314 convert_to_section_size_type(this->data_size());
1315 unsigned char* const oview = of->get_output_view(offset, oview_size);
1317 const off_t got_file_offset = this->got_plt_->offset();
1318 gold_assert(parameters->incremental_update()
1319 || (got_file_offset + this->got_plt_->data_size()
1320 == this->got_irelative_->offset()));
1321 const section_size_type got_size =
1322 convert_to_section_size_type(this->got_plt_->data_size()
1323 + this->got_irelative_->data_size());
1324 unsigned char* const got_view = of->get_output_view(got_file_offset,
1327 unsigned char* pov = oview;
1329 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1330 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1332 this->fill_first_plt_entry(pov, got_address);
1333 pov += this->get_plt_entry_size();
1335 unsigned char* got_pov = got_view;
1337 // The first entry in the GOT is the address of the .dynamic section
1338 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1339 // We saved space for them when we created the section in
1340 // Target_i386::got_section.
1341 Output_section* dynamic = this->layout_->dynamic_section();
1342 uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1343 elfcpp::Swap<32, false>::writeval(got_pov, dynamic_addr);
1345 memset(got_pov, 0, 8);
1348 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1350 unsigned int plt_offset = this->get_plt_entry_size();
1351 unsigned int plt_rel_offset = 0;
1352 unsigned int got_offset = 12;
1353 const unsigned int count = this->count_ + this->irelative_count_;
1354 for (unsigned int i = 0;
1357 pov += this->get_plt_entry_size(),
1359 plt_offset += this->get_plt_entry_size(),
1360 plt_rel_offset += rel_size,
1363 // Set and adjust the PLT entry itself.
1364 unsigned int lazy_offset = this->fill_plt_entry(pov,
1370 // Set the entry in the GOT.
1371 elfcpp::Swap<32, false>::writeval(got_pov,
1372 plt_address + plt_offset + lazy_offset);
1375 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1376 // the GOT to point to the actual symbol value, rather than point to
1377 // the PLT entry. That will let the dynamic linker call the right
1378 // function when resolving IRELATIVE relocations.
1379 unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1380 for (std::vector<Global_ifunc>::const_iterator p =
1381 this->global_ifuncs_.begin();
1382 p != this->global_ifuncs_.end();
1385 const Sized_symbol<32>* ssym =
1386 static_cast<const Sized_symbol<32>*>(p->sym);
1387 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1391 for (std::vector<Local_ifunc>::const_iterator p =
1392 this->local_ifuncs_.begin();
1393 p != this->local_ifuncs_.end();
1396 const Symbol_value<32>* psymval =
1397 p->object->local_symbol(p->local_sym_index);
1398 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1399 psymval->value(p->object, 0));
1402 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1403 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1405 of->write_output_view(offset, oview_size, oview);
1406 of->write_output_view(got_file_offset, got_size, got_view);
1409 // Create the PLT section.
1412 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1414 if (this->plt_ == NULL)
1416 // Create the GOT sections first.
1417 this->got_section(symtab, layout);
1419 const bool dyn = parameters->options().output_is_position_independent();
1420 this->plt_ = this->make_data_plt(layout,
1422 this->got_irelative_,
1425 // Add unwind information if requested.
1426 if (parameters->options().ld_generated_unwind_info())
1427 this->plt_->add_eh_frame(layout);
1429 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1431 | elfcpp::SHF_EXECINSTR),
1432 this->plt_, ORDER_PLT, false);
1434 // Make the sh_info field of .rel.plt point to .plt.
1435 Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1436 rel_plt_os->set_info_section(this->plt_->output_section());
1440 // Create a PLT entry for a global symbol.
1443 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1445 if (gsym->has_plt_offset())
1447 if (this->plt_ == NULL)
1448 this->make_plt_section(symtab, layout);
1449 this->plt_->add_entry(symtab, layout, gsym);
1452 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1455 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1456 Sized_relobj_file<32, false>* relobj,
1457 unsigned int local_sym_index)
1459 if (relobj->local_has_plt_offset(local_sym_index))
1461 if (this->plt_ == NULL)
1462 this->make_plt_section(symtab, layout);
1463 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1466 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1469 // Return the number of entries in the PLT.
1472 Target_i386::plt_entry_count() const
1474 if (this->plt_ == NULL)
1476 return this->plt_->entry_count();
1479 // Return the offset of the first non-reserved PLT entry.
1482 Target_i386::first_plt_entry_offset() const
1484 return this->plt_->first_plt_entry_offset();
1487 // Return the size of each PLT entry.
1490 Target_i386::plt_entry_size() const
1492 return this->plt_->get_plt_entry_size();
1495 // Get the section to use for TLS_DESC relocations.
1497 Target_i386::Reloc_section*
1498 Target_i386::rel_tls_desc_section(Layout* layout) const
1500 return this->plt_section()->rel_tls_desc(layout);
1503 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1506 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1508 if (this->tls_base_symbol_defined_)
1511 Output_segment* tls_segment = layout->tls_segment();
1512 if (tls_segment != NULL)
1514 bool is_exec = parameters->options().output_is_executable();
1515 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1516 Symbol_table::PREDEFINED,
1520 elfcpp::STV_HIDDEN, 0,
1522 ? Symbol::SEGMENT_END
1523 : Symbol::SEGMENT_START),
1526 this->tls_base_symbol_defined_ = true;
1529 // Create a GOT entry for the TLS module index.
1532 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1533 Sized_relobj_file<32, false>* object)
1535 if (this->got_mod_index_offset_ == -1U)
1537 gold_assert(symtab != NULL && layout != NULL && object != NULL);
1538 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1539 Output_data_got<32, false>* got = this->got_section(symtab, layout);
1540 unsigned int got_offset = got->add_constant(0);
1541 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1543 got->add_constant(0);
1544 this->got_mod_index_offset_ = got_offset;
1546 return this->got_mod_index_offset_;
1549 // Optimize the TLS relocation type based on what we know about the
1550 // symbol. IS_FINAL is true if the final address of this symbol is
1551 // known at link time.
1553 tls::Tls_optimization
1554 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1556 // If we are generating a shared library, then we can't do anything
1558 if (parameters->options().shared())
1559 return tls::TLSOPT_NONE;
1563 case elfcpp::R_386_TLS_GD:
1564 case elfcpp::R_386_TLS_GOTDESC:
1565 case elfcpp::R_386_TLS_DESC_CALL:
1566 // These are General-Dynamic which permits fully general TLS
1567 // access. Since we know that we are generating an executable,
1568 // we can convert this to Initial-Exec. If we also know that
1569 // this is a local symbol, we can further switch to Local-Exec.
1571 return tls::TLSOPT_TO_LE;
1572 return tls::TLSOPT_TO_IE;
1574 case elfcpp::R_386_TLS_LDM:
1575 // This is Local-Dynamic, which refers to a local symbol in the
1576 // dynamic TLS block. Since we know that we generating an
1577 // executable, we can switch to Local-Exec.
1578 return tls::TLSOPT_TO_LE;
1580 case elfcpp::R_386_TLS_LDO_32:
1581 // Another type of Local-Dynamic relocation.
1582 return tls::TLSOPT_TO_LE;
1584 case elfcpp::R_386_TLS_IE:
1585 case elfcpp::R_386_TLS_GOTIE:
1586 case elfcpp::R_386_TLS_IE_32:
1587 // These are Initial-Exec relocs which get the thread offset
1588 // from the GOT. If we know that we are linking against the
1589 // local symbol, we can switch to Local-Exec, which links the
1590 // thread offset into the instruction.
1592 return tls::TLSOPT_TO_LE;
1593 return tls::TLSOPT_NONE;
1595 case elfcpp::R_386_TLS_LE:
1596 case elfcpp::R_386_TLS_LE_32:
1597 // When we already have Local-Exec, there is nothing further we
1599 return tls::TLSOPT_NONE;
1606 // Get the Reference_flags for a particular relocation.
1609 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1613 case elfcpp::R_386_NONE:
1614 case elfcpp::R_386_GNU_VTINHERIT:
1615 case elfcpp::R_386_GNU_VTENTRY:
1616 case elfcpp::R_386_GOTPC:
1617 // No symbol reference.
1620 case elfcpp::R_386_32:
1621 case elfcpp::R_386_16:
1622 case elfcpp::R_386_8:
1623 return Symbol::ABSOLUTE_REF;
1625 case elfcpp::R_386_PC32:
1626 case elfcpp::R_386_PC16:
1627 case elfcpp::R_386_PC8:
1628 case elfcpp::R_386_GOTOFF:
1629 return Symbol::RELATIVE_REF;
1631 case elfcpp::R_386_PLT32:
1632 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1634 case elfcpp::R_386_GOT32:
1636 return Symbol::ABSOLUTE_REF;
1638 case elfcpp::R_386_TLS_GD: // Global-dynamic
1639 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1640 case elfcpp::R_386_TLS_DESC_CALL:
1641 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1642 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1643 case elfcpp::R_386_TLS_IE: // Initial-exec
1644 case elfcpp::R_386_TLS_IE_32:
1645 case elfcpp::R_386_TLS_GOTIE:
1646 case elfcpp::R_386_TLS_LE: // Local-exec
1647 case elfcpp::R_386_TLS_LE_32:
1648 return Symbol::TLS_REF;
1650 case elfcpp::R_386_COPY:
1651 case elfcpp::R_386_GLOB_DAT:
1652 case elfcpp::R_386_JUMP_SLOT:
1653 case elfcpp::R_386_RELATIVE:
1654 case elfcpp::R_386_IRELATIVE:
1655 case elfcpp::R_386_TLS_TPOFF:
1656 case elfcpp::R_386_TLS_DTPMOD32:
1657 case elfcpp::R_386_TLS_DTPOFF32:
1658 case elfcpp::R_386_TLS_TPOFF32:
1659 case elfcpp::R_386_TLS_DESC:
1660 case elfcpp::R_386_32PLT:
1661 case elfcpp::R_386_TLS_GD_32:
1662 case elfcpp::R_386_TLS_GD_PUSH:
1663 case elfcpp::R_386_TLS_GD_CALL:
1664 case elfcpp::R_386_TLS_GD_POP:
1665 case elfcpp::R_386_TLS_LDM_32:
1666 case elfcpp::R_386_TLS_LDM_PUSH:
1667 case elfcpp::R_386_TLS_LDM_CALL:
1668 case elfcpp::R_386_TLS_LDM_POP:
1669 case elfcpp::R_386_USED_BY_INTEL_200:
1671 // Not expected. We will give an error later.
1676 // Report an unsupported relocation against a local symbol.
1679 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1680 unsigned int r_type)
1682 gold_error(_("%s: unsupported reloc %u against local symbol"),
1683 object->name().c_str(), r_type);
1686 // Return whether we need to make a PLT entry for a relocation of a
1687 // given type against a STT_GNU_IFUNC symbol.
1690 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1691 Sized_relobj_file<32, false>* object,
1692 unsigned int r_type)
1694 int flags = Scan::get_reference_flags(r_type);
1695 if (flags & Symbol::TLS_REF)
1696 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1697 object->name().c_str(), r_type);
1701 // Scan a relocation for a local symbol.
1704 Target_i386::Scan::local(Symbol_table* symtab,
1706 Target_i386* target,
1707 Sized_relobj_file<32, false>* object,
1708 unsigned int data_shndx,
1709 Output_section* output_section,
1710 const elfcpp::Rel<32, false>& reloc,
1711 unsigned int r_type,
1712 const elfcpp::Sym<32, false>& lsym)
1714 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1715 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1716 && this->reloc_needs_plt_for_ifunc(object, r_type))
1718 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1719 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1724 case elfcpp::R_386_NONE:
1725 case elfcpp::R_386_GNU_VTINHERIT:
1726 case elfcpp::R_386_GNU_VTENTRY:
1729 case elfcpp::R_386_32:
1730 // If building a shared library (or a position-independent
1731 // executable), we need to create a dynamic relocation for
1732 // this location. The relocation applied at link time will
1733 // apply the link-time value, so we flag the location with
1734 // an R_386_RELATIVE relocation so the dynamic loader can
1735 // relocate it easily.
1736 if (parameters->options().output_is_position_independent())
1738 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1739 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1740 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1741 output_section, data_shndx,
1742 reloc.get_r_offset());
1746 case elfcpp::R_386_16:
1747 case elfcpp::R_386_8:
1748 // If building a shared library (or a position-independent
1749 // executable), we need to create a dynamic relocation for
1750 // this location. Because the addend needs to remain in the
1751 // data section, we need to be careful not to apply this
1752 // relocation statically.
1753 if (parameters->options().output_is_position_independent())
1755 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1756 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1757 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1758 rel_dyn->add_local(object, r_sym, r_type, output_section,
1759 data_shndx, reloc.get_r_offset());
1762 gold_assert(lsym.get_st_value() == 0);
1763 unsigned int shndx = lsym.get_st_shndx();
1765 shndx = object->adjust_sym_shndx(r_sym, shndx,
1768 object->error(_("section symbol %u has bad shndx %u"),
1771 rel_dyn->add_local_section(object, shndx,
1772 r_type, output_section,
1773 data_shndx, reloc.get_r_offset());
1778 case elfcpp::R_386_PC32:
1779 case elfcpp::R_386_PC16:
1780 case elfcpp::R_386_PC8:
1783 case elfcpp::R_386_PLT32:
1784 // Since we know this is a local symbol, we can handle this as a
1788 case elfcpp::R_386_GOTOFF:
1789 case elfcpp::R_386_GOTPC:
1790 // We need a GOT section.
1791 target->got_section(symtab, layout);
1794 case elfcpp::R_386_GOT32:
1796 // The symbol requires a GOT entry.
1797 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1798 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1800 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1801 // lets function pointers compare correctly with shared
1802 // libraries. Otherwise we would need an IRELATIVE reloc.
1804 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1805 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1807 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1810 // If we are generating a shared object, we need to add a
1811 // dynamic RELATIVE relocation for this symbol's GOT entry.
1812 if (parameters->options().output_is_position_independent())
1814 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1815 unsigned int got_offset =
1816 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1817 rel_dyn->add_local_relative(object, r_sym,
1818 elfcpp::R_386_RELATIVE,
1825 // These are relocations which should only be seen by the
1826 // dynamic linker, and should never be seen here.
1827 case elfcpp::R_386_COPY:
1828 case elfcpp::R_386_GLOB_DAT:
1829 case elfcpp::R_386_JUMP_SLOT:
1830 case elfcpp::R_386_RELATIVE:
1831 case elfcpp::R_386_IRELATIVE:
1832 case elfcpp::R_386_TLS_TPOFF:
1833 case elfcpp::R_386_TLS_DTPMOD32:
1834 case elfcpp::R_386_TLS_DTPOFF32:
1835 case elfcpp::R_386_TLS_TPOFF32:
1836 case elfcpp::R_386_TLS_DESC:
1837 gold_error(_("%s: unexpected reloc %u in object file"),
1838 object->name().c_str(), r_type);
1841 // These are initial TLS relocs, which are expected when
1843 case elfcpp::R_386_TLS_GD: // Global-dynamic
1844 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1845 case elfcpp::R_386_TLS_DESC_CALL:
1846 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1847 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1848 case elfcpp::R_386_TLS_IE: // Initial-exec
1849 case elfcpp::R_386_TLS_IE_32:
1850 case elfcpp::R_386_TLS_GOTIE:
1851 case elfcpp::R_386_TLS_LE: // Local-exec
1852 case elfcpp::R_386_TLS_LE_32:
1854 bool output_is_shared = parameters->options().shared();
1855 const tls::Tls_optimization optimized_type
1856 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1859 case elfcpp::R_386_TLS_GD: // Global-dynamic
1860 if (optimized_type == tls::TLSOPT_NONE)
1862 // Create a pair of GOT entries for the module index and
1863 // dtv-relative offset.
1864 Output_data_got<32, false>* got
1865 = target->got_section(symtab, layout);
1866 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1867 unsigned int shndx = lsym.get_st_shndx();
1869 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1871 object->error(_("local symbol %u has bad shndx %u"),
1874 got->add_local_pair_with_rel(object, r_sym, shndx,
1876 target->rel_dyn_section(layout),
1877 elfcpp::R_386_TLS_DTPMOD32, 0);
1879 else if (optimized_type != tls::TLSOPT_TO_LE)
1880 unsupported_reloc_local(object, r_type);
1883 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1884 target->define_tls_base_symbol(symtab, layout);
1885 if (optimized_type == tls::TLSOPT_NONE)
1887 // Create a double GOT entry with an R_386_TLS_DESC
1888 // reloc. The R_386_TLS_DESC reloc is resolved
1889 // lazily, so the GOT entry needs to be in an area in
1890 // .got.plt, not .got. Call got_section to make sure
1891 // the section has been created.
1892 target->got_section(symtab, layout);
1893 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1894 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1895 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1897 unsigned int got_offset = got->add_constant(0);
1898 // The local symbol value is stored in the second
1900 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1901 // That set the GOT offset of the local symbol to
1902 // point to the second entry, but we want it to
1903 // point to the first.
1904 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1906 Reloc_section* rt = target->rel_tls_desc_section(layout);
1907 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1910 else if (optimized_type != tls::TLSOPT_TO_LE)
1911 unsupported_reloc_local(object, r_type);
1914 case elfcpp::R_386_TLS_DESC_CALL:
1917 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1918 if (optimized_type == tls::TLSOPT_NONE)
1920 // Create a GOT entry for the module index.
1921 target->got_mod_index_entry(symtab, layout, object);
1923 else if (optimized_type != tls::TLSOPT_TO_LE)
1924 unsupported_reloc_local(object, r_type);
1927 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1930 case elfcpp::R_386_TLS_IE: // Initial-exec
1931 case elfcpp::R_386_TLS_IE_32:
1932 case elfcpp::R_386_TLS_GOTIE:
1933 layout->set_has_static_tls();
1934 if (optimized_type == tls::TLSOPT_NONE)
1936 // For the R_386_TLS_IE relocation, we need to create a
1937 // dynamic relocation when building a shared library.
1938 if (r_type == elfcpp::R_386_TLS_IE
1939 && parameters->options().shared())
1941 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1943 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1944 rel_dyn->add_local_relative(object, r_sym,
1945 elfcpp::R_386_RELATIVE,
1946 output_section, data_shndx,
1947 reloc.get_r_offset());
1949 // Create a GOT entry for the tp-relative offset.
1950 Output_data_got<32, false>* got
1951 = target->got_section(symtab, layout);
1952 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1953 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1954 ? elfcpp::R_386_TLS_TPOFF32
1955 : elfcpp::R_386_TLS_TPOFF);
1956 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1957 ? GOT_TYPE_TLS_OFFSET
1958 : GOT_TYPE_TLS_NOFFSET);
1959 got->add_local_with_rel(object, r_sym, got_type,
1960 target->rel_dyn_section(layout),
1963 else if (optimized_type != tls::TLSOPT_TO_LE)
1964 unsupported_reloc_local(object, r_type);
1967 case elfcpp::R_386_TLS_LE: // Local-exec
1968 case elfcpp::R_386_TLS_LE_32:
1969 layout->set_has_static_tls();
1970 if (output_is_shared)
1972 // We need to create a dynamic relocation.
1973 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1974 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1975 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1976 ? elfcpp::R_386_TLS_TPOFF32
1977 : elfcpp::R_386_TLS_TPOFF);
1978 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1979 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1980 data_shndx, reloc.get_r_offset());
1990 case elfcpp::R_386_32PLT:
1991 case elfcpp::R_386_TLS_GD_32:
1992 case elfcpp::R_386_TLS_GD_PUSH:
1993 case elfcpp::R_386_TLS_GD_CALL:
1994 case elfcpp::R_386_TLS_GD_POP:
1995 case elfcpp::R_386_TLS_LDM_32:
1996 case elfcpp::R_386_TLS_LDM_PUSH:
1997 case elfcpp::R_386_TLS_LDM_CALL:
1998 case elfcpp::R_386_TLS_LDM_POP:
1999 case elfcpp::R_386_USED_BY_INTEL_200:
2001 unsupported_reloc_local(object, r_type);
2006 // Report an unsupported relocation against a global symbol.
2009 Target_i386::Scan::unsupported_reloc_global(
2010 Sized_relobj_file<32, false>* object,
2011 unsigned int r_type,
2014 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2015 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2019 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
2023 case elfcpp::R_386_32:
2024 case elfcpp::R_386_16:
2025 case elfcpp::R_386_8:
2026 case elfcpp::R_386_GOTOFF:
2027 case elfcpp::R_386_GOT32:
2038 Target_i386::Scan::local_reloc_may_be_function_pointer(
2042 Sized_relobj_file<32, false>* ,
2045 const elfcpp::Rel<32, false>& ,
2046 unsigned int r_type,
2047 const elfcpp::Sym<32, false>&)
2049 return possible_function_pointer_reloc(r_type);
2053 Target_i386::Scan::global_reloc_may_be_function_pointer(
2057 Sized_relobj_file<32, false>* ,
2060 const elfcpp::Rel<32, false>& ,
2061 unsigned int r_type,
2064 return possible_function_pointer_reloc(r_type);
2067 // Scan a relocation for a global symbol.
2070 Target_i386::Scan::global(Symbol_table* symtab,
2072 Target_i386* target,
2073 Sized_relobj_file<32, false>* object,
2074 unsigned int data_shndx,
2075 Output_section* output_section,
2076 const elfcpp::Rel<32, false>& reloc,
2077 unsigned int r_type,
2080 // A STT_GNU_IFUNC symbol may require a PLT entry.
2081 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2082 && this->reloc_needs_plt_for_ifunc(object, r_type))
2083 target->make_plt_entry(symtab, layout, gsym);
2087 case elfcpp::R_386_NONE:
2088 case elfcpp::R_386_GNU_VTINHERIT:
2089 case elfcpp::R_386_GNU_VTENTRY:
2092 case elfcpp::R_386_32:
2093 case elfcpp::R_386_16:
2094 case elfcpp::R_386_8:
2096 // Make a PLT entry if necessary.
2097 if (gsym->needs_plt_entry())
2099 target->make_plt_entry(symtab, layout, gsym);
2100 // Since this is not a PC-relative relocation, we may be
2101 // taking the address of a function. In that case we need to
2102 // set the entry in the dynamic symbol table to the address of
2104 if (gsym->is_from_dynobj() && !parameters->options().shared())
2105 gsym->set_needs_dynsym_value();
2107 // Make a dynamic relocation if necessary.
2108 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2110 if (gsym->may_need_copy_reloc())
2112 target->copy_reloc(symtab, layout, object,
2113 data_shndx, output_section, gsym, reloc);
2115 else if (r_type == elfcpp::R_386_32
2116 && gsym->type() == elfcpp::STT_GNU_IFUNC
2117 && gsym->can_use_relative_reloc(false)
2118 && !gsym->is_from_dynobj()
2119 && !gsym->is_undefined()
2120 && !gsym->is_preemptible())
2122 // Use an IRELATIVE reloc for a locally defined
2123 // STT_GNU_IFUNC symbol. This makes a function
2124 // address in a PIE executable match the address in a
2125 // shared library that it links against.
2126 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
2127 rel_dyn->add_symbolless_global_addend(gsym,
2128 elfcpp::R_386_IRELATIVE,
2131 reloc.get_r_offset());
2133 else if (r_type == elfcpp::R_386_32
2134 && gsym->can_use_relative_reloc(false))
2136 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2137 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2138 output_section, object,
2139 data_shndx, reloc.get_r_offset());
2143 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2144 rel_dyn->add_global(gsym, r_type, output_section, object,
2145 data_shndx, reloc.get_r_offset());
2151 case elfcpp::R_386_PC32:
2152 case elfcpp::R_386_PC16:
2153 case elfcpp::R_386_PC8:
2155 // Make a PLT entry if necessary.
2156 if (gsym->needs_plt_entry())
2158 // These relocations are used for function calls only in
2159 // non-PIC code. For a 32-bit relocation in a shared library,
2160 // we'll need a text relocation anyway, so we can skip the
2161 // PLT entry and let the dynamic linker bind the call directly
2162 // to the target. For smaller relocations, we should use a
2163 // PLT entry to ensure that the call can reach.
2164 if (!parameters->options().shared()
2165 || r_type != elfcpp::R_386_PC32)
2166 target->make_plt_entry(symtab, layout, gsym);
2168 // Make a dynamic relocation if necessary.
2169 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2171 if (gsym->may_need_copy_reloc())
2173 target->copy_reloc(symtab, layout, object,
2174 data_shndx, output_section, gsym, reloc);
2178 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2179 rel_dyn->add_global(gsym, r_type, output_section, object,
2180 data_shndx, reloc.get_r_offset());
2186 case elfcpp::R_386_GOT32:
2188 // The symbol requires a GOT entry.
2189 Output_data_got<32, false>* got = target->got_section(symtab, layout);
2190 if (gsym->final_value_is_known())
2192 // For a STT_GNU_IFUNC symbol we want the PLT address.
2193 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2194 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2196 got->add_global(gsym, GOT_TYPE_STANDARD);
2200 // If this symbol is not fully resolved, we need to add a
2201 // GOT entry with a dynamic relocation.
2202 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2204 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2206 // 1) The symbol may be defined in some other module.
2208 // 2) We are building a shared library and this is a
2209 // protected symbol; using GLOB_DAT means that the dynamic
2210 // linker can use the address of the PLT in the main
2211 // executable when appropriate so that function address
2212 // comparisons work.
2214 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2215 // code, again so that function address comparisons work.
2216 if (gsym->is_from_dynobj()
2217 || gsym->is_undefined()
2218 || gsym->is_preemptible()
2219 || (gsym->visibility() == elfcpp::STV_PROTECTED
2220 && parameters->options().shared())
2221 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2222 && parameters->options().output_is_position_independent()))
2223 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2224 rel_dyn, elfcpp::R_386_GLOB_DAT);
2227 // For a STT_GNU_IFUNC symbol we want to write the PLT
2228 // offset into the GOT, so that function pointer
2229 // comparisons work correctly.
2231 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2232 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2235 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2236 // Tell the dynamic linker to use the PLT address
2237 // when resolving relocations.
2238 if (gsym->is_from_dynobj()
2239 && !parameters->options().shared())
2240 gsym->set_needs_dynsym_value();
2244 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2245 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2253 case elfcpp::R_386_PLT32:
2254 // If the symbol is fully resolved, this is just a PC32 reloc.
2255 // Otherwise we need a PLT entry.
2256 if (gsym->final_value_is_known())
2258 // If building a shared library, we can also skip the PLT entry
2259 // if the symbol is defined in the output file and is protected
2261 if (gsym->is_defined()
2262 && !gsym->is_from_dynobj()
2263 && !gsym->is_preemptible())
2265 target->make_plt_entry(symtab, layout, gsym);
2268 case elfcpp::R_386_GOTOFF:
2269 case elfcpp::R_386_GOTPC:
2270 // We need a GOT section.
2271 target->got_section(symtab, layout);
2274 // These are relocations which should only be seen by the
2275 // dynamic linker, and should never be seen here.
2276 case elfcpp::R_386_COPY:
2277 case elfcpp::R_386_GLOB_DAT:
2278 case elfcpp::R_386_JUMP_SLOT:
2279 case elfcpp::R_386_RELATIVE:
2280 case elfcpp::R_386_IRELATIVE:
2281 case elfcpp::R_386_TLS_TPOFF:
2282 case elfcpp::R_386_TLS_DTPMOD32:
2283 case elfcpp::R_386_TLS_DTPOFF32:
2284 case elfcpp::R_386_TLS_TPOFF32:
2285 case elfcpp::R_386_TLS_DESC:
2286 gold_error(_("%s: unexpected reloc %u in object file"),
2287 object->name().c_str(), r_type);
2290 // These are initial tls relocs, which are expected when
2292 case elfcpp::R_386_TLS_GD: // Global-dynamic
2293 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2294 case elfcpp::R_386_TLS_DESC_CALL:
2295 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2296 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2297 case elfcpp::R_386_TLS_IE: // Initial-exec
2298 case elfcpp::R_386_TLS_IE_32:
2299 case elfcpp::R_386_TLS_GOTIE:
2300 case elfcpp::R_386_TLS_LE: // Local-exec
2301 case elfcpp::R_386_TLS_LE_32:
2303 const bool is_final = gsym->final_value_is_known();
2304 const tls::Tls_optimization optimized_type
2305 = Target_i386::optimize_tls_reloc(is_final, r_type);
2308 case elfcpp::R_386_TLS_GD: // Global-dynamic
2309 if (optimized_type == tls::TLSOPT_NONE)
2311 // Create a pair of GOT entries for the module index and
2312 // dtv-relative offset.
2313 Output_data_got<32, false>* got
2314 = target->got_section(symtab, layout);
2315 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2316 target->rel_dyn_section(layout),
2317 elfcpp::R_386_TLS_DTPMOD32,
2318 elfcpp::R_386_TLS_DTPOFF32);
2320 else if (optimized_type == tls::TLSOPT_TO_IE)
2322 // Create a GOT entry for the tp-relative offset.
2323 Output_data_got<32, false>* got
2324 = target->got_section(symtab, layout);
2325 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2326 target->rel_dyn_section(layout),
2327 elfcpp::R_386_TLS_TPOFF);
2329 else if (optimized_type != tls::TLSOPT_TO_LE)
2330 unsupported_reloc_global(object, r_type, gsym);
2333 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
2334 target->define_tls_base_symbol(symtab, layout);
2335 if (optimized_type == tls::TLSOPT_NONE)
2337 // Create a double GOT entry with an R_386_TLS_DESC
2338 // reloc. The R_386_TLS_DESC reloc is resolved
2339 // lazily, so the GOT entry needs to be in an area in
2340 // .got.plt, not .got. Call got_section to make sure
2341 // the section has been created.
2342 target->got_section(symtab, layout);
2343 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2344 Reloc_section* rt = target->rel_tls_desc_section(layout);
2345 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2346 elfcpp::R_386_TLS_DESC, 0);
2348 else if (optimized_type == tls::TLSOPT_TO_IE)
2350 // Create a GOT entry for the tp-relative offset.
2351 Output_data_got<32, false>* got
2352 = target->got_section(symtab, layout);
2353 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2354 target->rel_dyn_section(layout),
2355 elfcpp::R_386_TLS_TPOFF);
2357 else if (optimized_type != tls::TLSOPT_TO_LE)
2358 unsupported_reloc_global(object, r_type, gsym);
2361 case elfcpp::R_386_TLS_DESC_CALL:
2364 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2365 if (optimized_type == tls::TLSOPT_NONE)
2367 // Create a GOT entry for the module index.
2368 target->got_mod_index_entry(symtab, layout, object);
2370 else if (optimized_type != tls::TLSOPT_TO_LE)
2371 unsupported_reloc_global(object, r_type, gsym);
2374 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2377 case elfcpp::R_386_TLS_IE: // Initial-exec
2378 case elfcpp::R_386_TLS_IE_32:
2379 case elfcpp::R_386_TLS_GOTIE:
2380 layout->set_has_static_tls();
2381 if (optimized_type == tls::TLSOPT_NONE)
2383 // For the R_386_TLS_IE relocation, we need to create a
2384 // dynamic relocation when building a shared library.
2385 if (r_type == elfcpp::R_386_TLS_IE
2386 && parameters->options().shared())
2388 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2389 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2390 output_section, object,
2392 reloc.get_r_offset());
2394 // Create a GOT entry for the tp-relative offset.
2395 Output_data_got<32, false>* got
2396 = target->got_section(symtab, layout);
2397 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2398 ? elfcpp::R_386_TLS_TPOFF32
2399 : elfcpp::R_386_TLS_TPOFF);
2400 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2401 ? GOT_TYPE_TLS_OFFSET
2402 : GOT_TYPE_TLS_NOFFSET);
2403 got->add_global_with_rel(gsym, got_type,
2404 target->rel_dyn_section(layout),
2407 else if (optimized_type != tls::TLSOPT_TO_LE)
2408 unsupported_reloc_global(object, r_type, gsym);
2411 case elfcpp::R_386_TLS_LE: // Local-exec
2412 case elfcpp::R_386_TLS_LE_32:
2413 layout->set_has_static_tls();
2414 if (parameters->options().shared())
2416 // We need to create a dynamic relocation.
2417 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2418 ? elfcpp::R_386_TLS_TPOFF32
2419 : elfcpp::R_386_TLS_TPOFF);
2420 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2421 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2422 data_shndx, reloc.get_r_offset());
2432 case elfcpp::R_386_32PLT:
2433 case elfcpp::R_386_TLS_GD_32:
2434 case elfcpp::R_386_TLS_GD_PUSH:
2435 case elfcpp::R_386_TLS_GD_CALL:
2436 case elfcpp::R_386_TLS_GD_POP:
2437 case elfcpp::R_386_TLS_LDM_32:
2438 case elfcpp::R_386_TLS_LDM_PUSH:
2439 case elfcpp::R_386_TLS_LDM_CALL:
2440 case elfcpp::R_386_TLS_LDM_POP:
2441 case elfcpp::R_386_USED_BY_INTEL_200:
2443 unsupported_reloc_global(object, r_type, gsym);
2448 // Process relocations for gc.
2451 Target_i386::gc_process_relocs(Symbol_table* symtab,
2453 Sized_relobj_file<32, false>* object,
2454 unsigned int data_shndx,
2456 const unsigned char* prelocs,
2458 Output_section* output_section,
2459 bool needs_special_offset_handling,
2460 size_t local_symbol_count,
2461 const unsigned char* plocal_symbols)
2463 gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2465 Target_i386::Relocatable_size_for_reloc>(
2474 needs_special_offset_handling,
2479 // Scan relocations for a section.
2482 Target_i386::scan_relocs(Symbol_table* symtab,
2484 Sized_relobj_file<32, false>* object,
2485 unsigned int data_shndx,
2486 unsigned int sh_type,
2487 const unsigned char* prelocs,
2489 Output_section* output_section,
2490 bool needs_special_offset_handling,
2491 size_t local_symbol_count,
2492 const unsigned char* plocal_symbols)
2494 if (sh_type == elfcpp::SHT_RELA)
2496 gold_error(_("%s: unsupported RELA reloc section"),
2497 object->name().c_str());
2501 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2511 needs_special_offset_handling,
2516 // Finalize the sections.
2519 Target_i386::do_finalize_sections(
2521 const Input_objects*,
2522 Symbol_table* symtab)
2524 const Reloc_section* rel_plt = (this->plt_ == NULL
2526 : this->plt_->rel_plt());
2527 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2528 this->rel_dyn_, true, false);
2530 // Emit any relocs we saved in an attempt to avoid generating COPY
2532 if (this->copy_relocs_.any_saved_relocs())
2533 this->copy_relocs_.emit(this->rel_dyn_section(layout));
2535 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2536 // the .got.plt section.
2537 Symbol* sym = this->global_offset_table_;
2540 uint32_t data_size = this->got_plt_->current_data_size();
2541 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2544 if (parameters->doing_static_link()
2545 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2547 // If linking statically, make sure that the __rel_iplt symbols
2548 // were defined if necessary, even if we didn't create a PLT.
2549 static const Define_symbol_in_segment syms[] =
2552 "__rel_iplt_start", // name
2553 elfcpp::PT_LOAD, // segment_type
2554 elfcpp::PF_W, // segment_flags_set
2555 elfcpp::PF(0), // segment_flags_clear
2558 elfcpp::STT_NOTYPE, // type
2559 elfcpp::STB_GLOBAL, // binding
2560 elfcpp::STV_HIDDEN, // visibility
2562 Symbol::SEGMENT_START, // offset_from_base
2566 "__rel_iplt_end", // name
2567 elfcpp::PT_LOAD, // segment_type
2568 elfcpp::PF_W, // segment_flags_set
2569 elfcpp::PF(0), // segment_flags_clear
2572 elfcpp::STT_NOTYPE, // type
2573 elfcpp::STB_GLOBAL, // binding
2574 elfcpp::STV_HIDDEN, // visibility
2576 Symbol::SEGMENT_START, // offset_from_base
2581 symtab->define_symbols(layout, 2, syms,
2582 layout->script_options()->saw_sections_clause());
2586 // Return whether a direct absolute static relocation needs to be applied.
2587 // In cases where Scan::local() or Scan::global() has created
2588 // a dynamic relocation other than R_386_RELATIVE, the addend
2589 // of the relocation is carried in the data, and we must not
2590 // apply the static relocation.
2593 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2594 unsigned int r_type,
2596 Output_section* output_section)
2598 // If the output section is not allocated, then we didn't call
2599 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2601 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2604 int ref_flags = Scan::get_reference_flags(r_type);
2606 // For local symbols, we will have created a non-RELATIVE dynamic
2607 // relocation only if (a) the output is position independent,
2608 // (b) the relocation is absolute (not pc- or segment-relative), and
2609 // (c) the relocation is not 32 bits wide.
2611 return !(parameters->options().output_is_position_independent()
2612 && (ref_flags & Symbol::ABSOLUTE_REF)
2615 // For global symbols, we use the same helper routines used in the
2616 // scan pass. If we did not create a dynamic relocation, or if we
2617 // created a RELATIVE dynamic relocation, we should apply the static
2619 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2620 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2621 && gsym->can_use_relative_reloc(ref_flags
2622 & Symbol::FUNCTION_CALL);
2623 return !has_dyn || is_rel;
2626 // Perform a relocation.
2629 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2630 Target_i386* target,
2631 Output_section* output_section,
2633 const elfcpp::Rel<32, false>& rel,
2634 unsigned int r_type,
2635 const Sized_symbol<32>* gsym,
2636 const Symbol_value<32>* psymval,
2637 unsigned char* view,
2638 elfcpp::Elf_types<32>::Elf_Addr address,
2639 section_size_type view_size)
2641 if (this->skip_call_tls_get_addr_)
2643 if ((r_type != elfcpp::R_386_PLT32
2644 && r_type != elfcpp::R_386_PC32)
2646 || strcmp(gsym->name(), "___tls_get_addr") != 0)
2647 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2648 _("missing expected TLS relocation"));
2651 this->skip_call_tls_get_addr_ = false;
2656 const Sized_relobj_file<32, false>* object = relinfo->object;
2658 // Pick the value to use for symbols defined in shared objects.
2659 Symbol_value<32> symval;
2661 && gsym->type() == elfcpp::STT_GNU_IFUNC
2662 && r_type == elfcpp::R_386_32
2663 && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2664 && gsym->can_use_relative_reloc(false)
2665 && !gsym->is_from_dynobj()
2666 && !gsym->is_undefined()
2667 && !gsym->is_preemptible())
2669 // In this case we are generating a R_386_IRELATIVE reloc. We
2670 // want to use the real value of the symbol, not the PLT offset.
2672 else if (gsym != NULL
2673 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2675 symval.set_output_value(target->plt_address_for_global(gsym)
2676 + gsym->plt_offset());
2679 else if (gsym == NULL && psymval->is_ifunc_symbol())
2681 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2682 if (object->local_has_plt_offset(r_sym))
2684 symval.set_output_value(target->plt_address_for_local(object, r_sym)
2685 + object->local_plt_offset(r_sym));
2690 // Get the GOT offset if needed.
2691 // The GOT pointer points to the end of the GOT section.
2692 // We need to subtract the size of the GOT section to get
2693 // the actual offset to use in the relocation.
2694 bool have_got_offset = false;
2695 unsigned int got_offset = 0;
2698 case elfcpp::R_386_GOT32:
2701 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2702 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2703 - target->got_size());
2707 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2708 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2709 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2710 - target->got_size());
2712 have_got_offset = true;
2721 case elfcpp::R_386_NONE:
2722 case elfcpp::R_386_GNU_VTINHERIT:
2723 case elfcpp::R_386_GNU_VTENTRY:
2726 case elfcpp::R_386_32:
2727 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2728 Relocate_functions<32, false>::rel32(view, object, psymval);
2731 case elfcpp::R_386_PC32:
2732 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2733 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2736 case elfcpp::R_386_16:
2737 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2738 Relocate_functions<32, false>::rel16(view, object, psymval);
2741 case elfcpp::R_386_PC16:
2742 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2743 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2746 case elfcpp::R_386_8:
2747 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2748 Relocate_functions<32, false>::rel8(view, object, psymval);
2751 case elfcpp::R_386_PC8:
2752 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2753 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2756 case elfcpp::R_386_PLT32:
2757 gold_assert(gsym == NULL
2758 || gsym->has_plt_offset()
2759 || gsym->final_value_is_known()
2760 || (gsym->is_defined()
2761 && !gsym->is_from_dynobj()
2762 && !gsym->is_preemptible()));
2763 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2766 case elfcpp::R_386_GOT32:
2767 gold_assert(have_got_offset);
2768 Relocate_functions<32, false>::rel32(view, got_offset);
2771 case elfcpp::R_386_GOTOFF:
2773 elfcpp::Elf_types<32>::Elf_Addr value;
2774 value = (psymval->value(object, 0)
2775 - target->got_plt_section()->address());
2776 Relocate_functions<32, false>::rel32(view, value);
2780 case elfcpp::R_386_GOTPC:
2782 elfcpp::Elf_types<32>::Elf_Addr value;
2783 value = target->got_plt_section()->address();
2784 Relocate_functions<32, false>::pcrel32(view, value, address);
2788 case elfcpp::R_386_COPY:
2789 case elfcpp::R_386_GLOB_DAT:
2790 case elfcpp::R_386_JUMP_SLOT:
2791 case elfcpp::R_386_RELATIVE:
2792 case elfcpp::R_386_IRELATIVE:
2793 // These are outstanding tls relocs, which are unexpected when
2795 case elfcpp::R_386_TLS_TPOFF:
2796 case elfcpp::R_386_TLS_DTPMOD32:
2797 case elfcpp::R_386_TLS_DTPOFF32:
2798 case elfcpp::R_386_TLS_TPOFF32:
2799 case elfcpp::R_386_TLS_DESC:
2800 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2801 _("unexpected reloc %u in object file"),
2805 // These are initial tls relocs, which are expected when
2807 case elfcpp::R_386_TLS_GD: // Global-dynamic
2808 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2809 case elfcpp::R_386_TLS_DESC_CALL:
2810 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2811 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2812 case elfcpp::R_386_TLS_IE: // Initial-exec
2813 case elfcpp::R_386_TLS_IE_32:
2814 case elfcpp::R_386_TLS_GOTIE:
2815 case elfcpp::R_386_TLS_LE: // Local-exec
2816 case elfcpp::R_386_TLS_LE_32:
2817 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2818 view, address, view_size);
2821 case elfcpp::R_386_32PLT:
2822 case elfcpp::R_386_TLS_GD_32:
2823 case elfcpp::R_386_TLS_GD_PUSH:
2824 case elfcpp::R_386_TLS_GD_CALL:
2825 case elfcpp::R_386_TLS_GD_POP:
2826 case elfcpp::R_386_TLS_LDM_32:
2827 case elfcpp::R_386_TLS_LDM_PUSH:
2828 case elfcpp::R_386_TLS_LDM_CALL:
2829 case elfcpp::R_386_TLS_LDM_POP:
2830 case elfcpp::R_386_USED_BY_INTEL_200:
2832 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2833 _("unsupported reloc %u"),
2841 // Perform a TLS relocation.
2844 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2845 Target_i386* target,
2847 const elfcpp::Rel<32, false>& rel,
2848 unsigned int r_type,
2849 const Sized_symbol<32>* gsym,
2850 const Symbol_value<32>* psymval,
2851 unsigned char* view,
2852 elfcpp::Elf_types<32>::Elf_Addr,
2853 section_size_type view_size)
2855 Output_segment* tls_segment = relinfo->layout->tls_segment();
2857 const Sized_relobj_file<32, false>* object = relinfo->object;
2859 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2861 const bool is_final = (gsym == NULL
2862 ? !parameters->options().shared()
2863 : gsym->final_value_is_known());
2864 const tls::Tls_optimization optimized_type
2865 = Target_i386::optimize_tls_reloc(is_final, r_type);
2868 case elfcpp::R_386_TLS_GD: // Global-dynamic
2869 if (optimized_type == tls::TLSOPT_TO_LE)
2871 if (tls_segment == NULL)
2873 gold_assert(parameters->errors()->error_count() > 0
2874 || issue_undefined_symbol_error(gsym));
2877 this->tls_gd_to_le(relinfo, relnum, tls_segment,
2878 rel, r_type, value, view,
2884 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2885 ? GOT_TYPE_TLS_NOFFSET
2886 : GOT_TYPE_TLS_PAIR);
2887 unsigned int got_offset;
2890 gold_assert(gsym->has_got_offset(got_type));
2891 got_offset = gsym->got_offset(got_type) - target->got_size();
2895 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2896 gold_assert(object->local_has_got_offset(r_sym, got_type));
2897 got_offset = (object->local_got_offset(r_sym, got_type)
2898 - target->got_size());
2900 if (optimized_type == tls::TLSOPT_TO_IE)
2902 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2903 got_offset, view, view_size);
2906 else if (optimized_type == tls::TLSOPT_NONE)
2908 // Relocate the field with the offset of the pair of GOT
2910 Relocate_functions<32, false>::rel32(view, got_offset);
2914 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2915 _("unsupported reloc %u"),
2919 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2920 case elfcpp::R_386_TLS_DESC_CALL:
2921 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2922 if (optimized_type == tls::TLSOPT_TO_LE)
2924 if (tls_segment == NULL)
2926 gold_assert(parameters->errors()->error_count() > 0
2927 || issue_undefined_symbol_error(gsym));
2930 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2931 rel, r_type, value, view,
2937 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2938 ? GOT_TYPE_TLS_NOFFSET
2939 : GOT_TYPE_TLS_DESC);
2940 unsigned int got_offset = 0;
2941 if (r_type == elfcpp::R_386_TLS_GOTDESC
2942 && optimized_type == tls::TLSOPT_NONE)
2944 // We created GOT entries in the .got.tlsdesc portion of
2945 // the .got.plt section, but the offset stored in the
2946 // symbol is the offset within .got.tlsdesc.
2947 got_offset = (target->got_size()
2948 + target->got_plt_section()->data_size());
2952 gold_assert(gsym->has_got_offset(got_type));
2953 got_offset += gsym->got_offset(got_type) - target->got_size();
2957 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2958 gold_assert(object->local_has_got_offset(r_sym, got_type));
2959 got_offset += (object->local_got_offset(r_sym, got_type)
2960 - target->got_size());
2962 if (optimized_type == tls::TLSOPT_TO_IE)
2964 if (tls_segment == NULL)
2966 gold_assert(parameters->errors()->error_count() > 0
2967 || issue_undefined_symbol_error(gsym));
2970 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2971 got_offset, view, view_size);
2974 else if (optimized_type == tls::TLSOPT_NONE)
2976 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2978 // Relocate the field with the offset of the pair of GOT
2980 Relocate_functions<32, false>::rel32(view, got_offset);
2985 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2986 _("unsupported reloc %u"),
2990 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2991 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2993 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2994 _("both SUN and GNU model "
2995 "TLS relocations"));
2998 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2999 if (optimized_type == tls::TLSOPT_TO_LE)
3001 if (tls_segment == NULL)
3003 gold_assert(parameters->errors()->error_count() > 0
3004 || issue_undefined_symbol_error(gsym));
3007 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
3008 value, view, view_size);
3011 else if (optimized_type == tls::TLSOPT_NONE)
3013 // Relocate the field with the offset of the GOT entry for
3014 // the module index.
3015 unsigned int got_offset;
3016 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3017 - target->got_size());
3018 Relocate_functions<32, false>::rel32(view, got_offset);
3021 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3022 _("unsupported reloc %u"),
3026 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3027 if (optimized_type == tls::TLSOPT_TO_LE)
3029 // This reloc can appear in debugging sections, in which
3030 // case we must not convert to local-exec. We decide what
3031 // to do based on whether the section is marked as
3032 // containing executable code. That is what the GNU linker
3034 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
3035 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
3037 if (tls_segment == NULL)
3039 gold_assert(parameters->errors()->error_count() > 0
3040 || issue_undefined_symbol_error(gsym));
3043 value -= tls_segment->memsz();
3046 Relocate_functions<32, false>::rel32(view, value);
3049 case elfcpp::R_386_TLS_IE: // Initial-exec
3050 case elfcpp::R_386_TLS_GOTIE:
3051 case elfcpp::R_386_TLS_IE_32:
3052 if (optimized_type == tls::TLSOPT_TO_LE)
3054 if (tls_segment == NULL)
3056 gold_assert(parameters->errors()->error_count() > 0
3057 || issue_undefined_symbol_error(gsym));
3060 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3061 rel, r_type, value, view,
3065 else if (optimized_type == tls::TLSOPT_NONE)
3067 // Relocate the field with the offset of the GOT entry for
3068 // the tp-relative offset of the symbol.
3069 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
3070 ? GOT_TYPE_TLS_OFFSET
3071 : GOT_TYPE_TLS_NOFFSET);
3072 unsigned int got_offset;
3075 gold_assert(gsym->has_got_offset(got_type));
3076 got_offset = gsym->got_offset(got_type);
3080 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3081 gold_assert(object->local_has_got_offset(r_sym, got_type));
3082 got_offset = object->local_got_offset(r_sym, got_type);
3084 // For the R_386_TLS_IE relocation, we need to apply the
3085 // absolute address of the GOT entry.
3086 if (r_type == elfcpp::R_386_TLS_IE)
3087 got_offset += target->got_plt_section()->address();
3088 // All GOT offsets are relative to the end of the GOT.
3089 got_offset -= target->got_size();
3090 Relocate_functions<32, false>::rel32(view, got_offset);
3093 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3094 _("unsupported reloc %u"),
3098 case elfcpp::R_386_TLS_LE: // Local-exec
3099 // If we're creating a shared library, a dynamic relocation will
3100 // have been created for this location, so do not apply it now.
3101 if (!parameters->options().shared())
3103 if (tls_segment == NULL)
3105 gold_assert(parameters->errors()->error_count() > 0
3106 || issue_undefined_symbol_error(gsym));
3109 value -= tls_segment->memsz();
3110 Relocate_functions<32, false>::rel32(view, value);
3114 case elfcpp::R_386_TLS_LE_32:
3115 // If we're creating a shared library, a dynamic relocation will
3116 // have been created for this location, so do not apply it now.
3117 if (!parameters->options().shared())
3119 if (tls_segment == NULL)
3121 gold_assert(parameters->errors()->error_count() > 0
3122 || issue_undefined_symbol_error(gsym));
3125 value = tls_segment->memsz() - value;
3126 Relocate_functions<32, false>::rel32(view, value);
3132 // Do a relocation in which we convert a TLS General-Dynamic to a
3136 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
3138 Output_segment* tls_segment,
3139 const elfcpp::Rel<32, false>& rel,
3141 elfcpp::Elf_types<32>::Elf_Addr value,
3142 unsigned char* view,
3143 section_size_type view_size)
3145 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3146 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3147 // leal foo(%reg),%eax; call ___tls_get_addr
3148 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3150 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3151 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3153 unsigned char op1 = view[-1];
3154 unsigned char op2 = view[-2];
3156 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3157 op2 == 0x8d || op2 == 0x04);
3158 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3164 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3165 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3166 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3167 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3168 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3172 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3173 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3174 if (rel.get_r_offset() + 9 < view_size
3177 // There is a trailing nop. Use the size byte subl.
3178 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3183 // Use the five byte subl.
3184 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3188 value = tls_segment->memsz() - value;
3189 Relocate_functions<32, false>::rel32(view + roff, value);
3191 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3193 this->skip_call_tls_get_addr_ = true;
3196 // Do a relocation in which we convert a TLS General-Dynamic to an
3200 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3203 const elfcpp::Rel<32, false>& rel,
3205 elfcpp::Elf_types<32>::Elf_Addr value,
3206 unsigned char* view,
3207 section_size_type view_size)
3209 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3210 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3212 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3213 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3215 unsigned char op1 = view[-1];
3216 unsigned char op2 = view[-2];
3218 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3219 op2 == 0x8d || op2 == 0x04);
3220 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3224 // FIXME: For now, support only the first (SIB) form.
3225 tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
3229 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3230 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3231 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3232 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3233 memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3237 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3238 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3239 if (rel.get_r_offset() + 9 < view_size
3242 // FIXME: This is not the right instruction sequence.
3243 // There is a trailing nop. Use the size byte subl.
3244 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3249 // FIXME: This is not the right instruction sequence.
3250 // Use the five byte subl.
3251 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3255 Relocate_functions<32, false>::rel32(view + roff, value);
3257 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3259 this->skip_call_tls_get_addr_ = true;
3262 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3263 // General-Dynamic to a Local-Exec.
3266 Target_i386::Relocate::tls_desc_gd_to_le(
3267 const Relocate_info<32, false>* relinfo,
3269 Output_segment* tls_segment,
3270 const elfcpp::Rel<32, false>& rel,
3271 unsigned int r_type,
3272 elfcpp::Elf_types<32>::Elf_Addr value,
3273 unsigned char* view,
3274 section_size_type view_size)
3276 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3278 // leal foo@TLSDESC(%ebx), %eax
3279 // ==> leal foo@NTPOFF, %eax
3280 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3281 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3282 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3283 view[-2] == 0x8d && view[-1] == 0x83);
3285 value -= tls_segment->memsz();
3286 Relocate_functions<32, false>::rel32(view, value);
3290 // call *foo@TLSCALL(%eax)
3292 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3293 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3294 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3295 view[0] == 0xff && view[1] == 0x10);
3301 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3302 // General-Dynamic to an Initial-Exec.
3305 Target_i386::Relocate::tls_desc_gd_to_ie(
3306 const Relocate_info<32, false>* relinfo,
3309 const elfcpp::Rel<32, false>& rel,
3310 unsigned int r_type,
3311 elfcpp::Elf_types<32>::Elf_Addr value,
3312 unsigned char* view,
3313 section_size_type view_size)
3315 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3317 // leal foo@TLSDESC(%ebx), %eax
3318 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3319 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3320 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3321 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3322 view[-2] == 0x8d && view[-1] == 0x83);
3324 Relocate_functions<32, false>::rel32(view, value);
3328 // call *foo@TLSCALL(%eax)
3330 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3331 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3332 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3333 view[0] == 0xff && view[1] == 0x10);
3339 // Do a relocation in which we convert a TLS Local-Dynamic to a
3343 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3346 const elfcpp::Rel<32, false>& rel,
3348 elfcpp::Elf_types<32>::Elf_Addr,
3349 unsigned char* view,
3350 section_size_type view_size)
3352 // leal foo(%reg), %eax; call ___tls_get_addr
3353 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3355 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3356 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3358 // FIXME: Does this test really always pass?
3359 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3360 view[-2] == 0x8d && view[-1] == 0x83);
3362 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3364 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3366 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3368 this->skip_call_tls_get_addr_ = true;
3371 // Do a relocation in which we convert a TLS Initial-Exec to a
3375 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3377 Output_segment* tls_segment,
3378 const elfcpp::Rel<32, false>& rel,
3379 unsigned int r_type,
3380 elfcpp::Elf_types<32>::Elf_Addr value,
3381 unsigned char* view,
3382 section_size_type view_size)
3384 // We have to actually change the instructions, which means that we
3385 // need to examine the opcodes to figure out which instruction we
3387 if (r_type == elfcpp::R_386_TLS_IE)
3389 // movl %gs:XX,%eax ==> movl $YY,%eax
3390 // movl %gs:XX,%reg ==> movl $YY,%reg
3391 // addl %gs:XX,%reg ==> addl $YY,%reg
3392 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3393 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3395 unsigned char op1 = view[-1];
3398 // movl XX,%eax ==> movl $YY,%eax
3403 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3405 unsigned char op2 = view[-2];
3408 // movl XX,%reg ==> movl $YY,%reg
3409 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3410 (op1 & 0xc7) == 0x05);
3412 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3414 else if (op2 == 0x03)
3416 // addl XX,%reg ==> addl $YY,%reg
3417 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3418 (op1 & 0xc7) == 0x05);
3420 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3423 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3428 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3429 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3430 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3431 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3432 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3434 unsigned char op1 = view[-1];
3435 unsigned char op2 = view[-2];
3436 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3437 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3440 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3442 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3444 else if (op2 == 0x2b)
3446 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3448 view[-1] = 0xe8 | ((op1 >> 3) & 7);
3450 else if (op2 == 0x03)
3452 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3454 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3457 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3460 value = tls_segment->memsz() - value;
3461 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3464 Relocate_functions<32, false>::rel32(view, value);
3467 // Relocate section data.
3470 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3471 unsigned int sh_type,
3472 const unsigned char* prelocs,
3474 Output_section* output_section,
3475 bool needs_special_offset_handling,
3476 unsigned char* view,
3477 elfcpp::Elf_types<32>::Elf_Addr address,
3478 section_size_type view_size,
3479 const Reloc_symbol_changes* reloc_symbol_changes)
3481 gold_assert(sh_type == elfcpp::SHT_REL);
3483 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
3484 Target_i386::Relocate>(
3490 needs_special_offset_handling,
3494 reloc_symbol_changes);
3497 // Return the size of a relocation while scanning during a relocatable
3501 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3502 unsigned int r_type,
3507 case elfcpp::R_386_NONE:
3508 case elfcpp::R_386_GNU_VTINHERIT:
3509 case elfcpp::R_386_GNU_VTENTRY:
3510 case elfcpp::R_386_TLS_GD: // Global-dynamic
3511 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3512 case elfcpp::R_386_TLS_DESC_CALL:
3513 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3514 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3515 case elfcpp::R_386_TLS_IE: // Initial-exec
3516 case elfcpp::R_386_TLS_IE_32:
3517 case elfcpp::R_386_TLS_GOTIE:
3518 case elfcpp::R_386_TLS_LE: // Local-exec
3519 case elfcpp::R_386_TLS_LE_32:
3522 case elfcpp::R_386_32:
3523 case elfcpp::R_386_PC32:
3524 case elfcpp::R_386_GOT32:
3525 case elfcpp::R_386_PLT32:
3526 case elfcpp::R_386_GOTOFF:
3527 case elfcpp::R_386_GOTPC:
3530 case elfcpp::R_386_16:
3531 case elfcpp::R_386_PC16:
3534 case elfcpp::R_386_8:
3535 case elfcpp::R_386_PC8:
3538 // These are relocations which should only be seen by the
3539 // dynamic linker, and should never be seen here.
3540 case elfcpp::R_386_COPY:
3541 case elfcpp::R_386_GLOB_DAT:
3542 case elfcpp::R_386_JUMP_SLOT:
3543 case elfcpp::R_386_RELATIVE:
3544 case elfcpp::R_386_IRELATIVE:
3545 case elfcpp::R_386_TLS_TPOFF:
3546 case elfcpp::R_386_TLS_DTPMOD32:
3547 case elfcpp::R_386_TLS_DTPOFF32:
3548 case elfcpp::R_386_TLS_TPOFF32:
3549 case elfcpp::R_386_TLS_DESC:
3550 object->error(_("unexpected reloc %u in object file"), r_type);
3553 case elfcpp::R_386_32PLT:
3554 case elfcpp::R_386_TLS_GD_32:
3555 case elfcpp::R_386_TLS_GD_PUSH:
3556 case elfcpp::R_386_TLS_GD_CALL:
3557 case elfcpp::R_386_TLS_GD_POP:
3558 case elfcpp::R_386_TLS_LDM_32:
3559 case elfcpp::R_386_TLS_LDM_PUSH:
3560 case elfcpp::R_386_TLS_LDM_CALL:
3561 case elfcpp::R_386_TLS_LDM_POP:
3562 case elfcpp::R_386_USED_BY_INTEL_200:
3564 object->error(_("unsupported reloc %u in object file"), r_type);
3569 // Scan the relocs during a relocatable link.
3572 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3574 Sized_relobj_file<32, false>* object,
3575 unsigned int data_shndx,
3576 unsigned int sh_type,
3577 const unsigned char* prelocs,
3579 Output_section* output_section,
3580 bool needs_special_offset_handling,
3581 size_t local_symbol_count,
3582 const unsigned char* plocal_symbols,
3583 Relocatable_relocs* rr)
3585 gold_assert(sh_type == elfcpp::SHT_REL);
3587 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3588 Relocatable_size_for_reloc> Scan_relocatable_relocs;
3590 gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3591 Scan_relocatable_relocs>(
3599 needs_special_offset_handling,
3605 // Emit relocations for a section.
3608 Target_i386::relocate_relocs(
3609 const Relocate_info<32, false>* relinfo,
3610 unsigned int sh_type,
3611 const unsigned char* prelocs,
3613 Output_section* output_section,
3614 off_t offset_in_output_section,
3615 const Relocatable_relocs* rr,
3616 unsigned char* view,
3617 elfcpp::Elf_types<32>::Elf_Addr view_address,
3618 section_size_type view_size,
3619 unsigned char* reloc_view,
3620 section_size_type reloc_view_size)
3622 gold_assert(sh_type == elfcpp::SHT_REL);
3624 gold::relocate_relocs<32, false, elfcpp::SHT_REL>(
3629 offset_in_output_section,
3638 // Return the value to use for a dynamic which requires special
3639 // treatment. This is how we support equality comparisons of function
3640 // pointers across shared library boundaries, as described in the
3641 // processor specific ABI supplement.
3644 Target_i386::do_dynsym_value(const Symbol* gsym) const
3646 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3647 return this->plt_address_for_global(gsym) + gsym->plt_offset();
3650 // Return a string used to fill a code section with nops to take up
3651 // the specified length.
3654 Target_i386::do_code_fill(section_size_type length) const
3658 // Build a jmp instruction to skip over the bytes.
3659 unsigned char jmp[5];
3661 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3662 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3663 + std::string(length - 5, static_cast<char>(0x90)));
3666 // Nop sequences of various lengths.
3667 const char nop1[1] = { '\x90' }; // nop
3668 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
3669 const char nop3[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3670 const char nop4[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3672 const char nop5[5] = { '\x90', '\x8d', '\x74', // nop
3673 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3674 const char nop6[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3675 '\x00', '\x00', '\x00' };
3676 const char nop7[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3677 '\x00', '\x00', '\x00',
3679 const char nop8[8] = { '\x90', '\x8d', '\xb4', // nop
3680 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3682 const char nop9[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3683 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3684 '\x00', '\x00', '\x00' };
3685 const char nop10[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3686 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3687 '\x00', '\x00', '\x00',
3689 const char nop11[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3690 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3691 '\x27', '\x00', '\x00',
3693 const char nop12[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3694 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3695 '\x8d', '\xbf', '\x00',
3696 '\x00', '\x00', '\x00' };
3697 const char nop13[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3698 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3699 '\x8d', '\xbc', '\x27',
3700 '\x00', '\x00', '\x00',
3702 const char nop14[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3703 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3704 '\x00', '\x8d', '\xbc',
3705 '\x27', '\x00', '\x00',
3707 const char nop15[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3708 '\x90', '\x90', '\x90', // nop,nop,nop,...
3709 '\x90', '\x90', '\x90',
3710 '\x90', '\x90', '\x90',
3711 '\x90', '\x90', '\x90' };
3713 const char* nops[16] = {
3715 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3716 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3719 return std::string(nops[length], length);
3722 // Return the value to use for the base of a DW_EH_PE_datarel offset
3723 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3724 // assembler can not write out the difference between two labels in
3725 // different sections, so instead of using a pc-relative value they
3726 // use an offset from the GOT.
3729 Target_i386::do_ehframe_datarel_base() const
3731 gold_assert(this->global_offset_table_ != NULL);
3732 Symbol* sym = this->global_offset_table_;
3733 Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3734 return ssym->value();
3737 // Return whether SYM should be treated as a call to a non-split
3738 // function. We don't want that to be true of a call to a
3739 // get_pc_thunk function.
3742 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3744 return (sym->type() == elfcpp::STT_FUNC
3745 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3748 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3749 // compiled with -fsplit-stack. The function calls non-split-stack
3750 // code. We have to change the function so that it always ensures
3751 // that it has enough stack space to run some random function.
3754 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3755 section_offset_type fnoffset,
3756 section_size_type fnsize,
3757 unsigned char* view,
3758 section_size_type view_size,
3760 std::string* to) const
3762 // The function starts with a comparison of the stack pointer and a
3763 // field in the TCB. This is followed by a jump.
3766 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3769 // We will call __morestack if the carry flag is set after this
3770 // comparison. We turn the comparison into an stc instruction
3772 view[fnoffset] = '\xf9';
3773 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3775 // lea NN(%esp),%ecx
3776 // lea NN(%esp),%edx
3777 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3778 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3781 // This is loading an offset from the stack pointer for a
3782 // comparison. The offset is negative, so we decrease the
3783 // offset by the amount of space we need for the stack. This
3784 // means we will avoid calling __morestack if there happens to
3785 // be plenty of space on the stack already.
3786 unsigned char* pval = view + fnoffset + 3;
3787 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3788 val -= parameters->options().split_stack_adjust_size();
3789 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3793 if (!object->has_no_split_stack())
3794 object->error(_("failed to match split-stack sequence at "
3795 "section %u offset %0zx"),
3796 shndx, static_cast<size_t>(fnoffset));
3800 // We have to change the function so that it calls
3801 // __morestack_non_split instead of __morestack. The former will
3802 // allocate additional stack space.
3803 *from = "__morestack";
3804 *to = "__morestack_non_split";
3807 // The selector for i386 object files. Note this is never instantiated
3808 // directly. It's only used in Target_selector_i386_nacl, below.
3810 class Target_selector_i386 : public Target_selector_freebsd
3813 Target_selector_i386()
3814 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3815 "elf32-i386", "elf32-i386-freebsd",
3820 do_instantiate_target()
3821 { return new Target_i386(); }
3824 // NaCl variant. It uses different PLT contents.
3826 class Output_data_plt_i386_nacl : public Output_data_plt_i386
3829 Output_data_plt_i386_nacl(Layout* layout,
3830 Output_data_space* got_plt,
3831 Output_data_space* got_irelative)
3832 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
3836 virtual unsigned int
3837 do_get_plt_entry_size() const
3838 { return plt_entry_size; }
3841 do_add_eh_frame(Layout* layout)
3843 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
3844 plt_eh_frame_fde, plt_eh_frame_fde_size);
3847 // The size of an entry in the PLT.
3848 static const int plt_entry_size = 64;
3850 // The .eh_frame unwind information for the PLT.
3851 static const int plt_eh_frame_fde_size = 32;
3852 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
3855 class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
3858 Output_data_plt_i386_nacl_exec(Layout* layout,
3859 Output_data_space* got_plt,
3860 Output_data_space* got_irelative)
3861 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
3866 do_fill_first_plt_entry(unsigned char* pov,
3867 elfcpp::Elf_types<32>::Elf_Addr got_address);
3869 virtual unsigned int
3870 do_fill_plt_entry(unsigned char* pov,
3871 elfcpp::Elf_types<32>::Elf_Addr got_address,
3872 unsigned int got_offset,
3873 unsigned int plt_offset,
3874 unsigned int plt_rel_offset);
3877 // The first entry in the PLT for an executable.
3878 static const unsigned char first_plt_entry[plt_entry_size];
3880 // Other entries in the PLT for an executable.
3881 static const unsigned char plt_entry[plt_entry_size];
3884 class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
3887 Output_data_plt_i386_nacl_dyn(Layout* layout,
3888 Output_data_space* got_plt,
3889 Output_data_space* got_irelative)
3890 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
3895 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
3897 virtual unsigned int
3898 do_fill_plt_entry(unsigned char* pov,
3899 elfcpp::Elf_types<32>::Elf_Addr,
3900 unsigned int got_offset,
3901 unsigned int plt_offset,
3902 unsigned int plt_rel_offset);
3905 // The first entry in the PLT for a shared object.
3906 static const unsigned char first_plt_entry[plt_entry_size];
3908 // Other entries in the PLT for a shared object.
3909 static const unsigned char plt_entry[plt_entry_size];
3912 class Target_i386_nacl : public Target_i386
3916 : Target_i386(&i386_nacl_info)
3920 virtual Output_data_plt_i386*
3921 do_make_data_plt(Layout* layout,
3922 Output_data_space* got_plt,
3923 Output_data_space* got_irelative,
3927 return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
3929 return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
3933 static const Target::Target_info i386_nacl_info;
3936 const Target::Target_info Target_i386_nacl::i386_nacl_info =
3939 false, // is_big_endian
3940 elfcpp::EM_386, // machine_code
3941 false, // has_make_symbol
3942 false, // has_resolve
3943 true, // has_code_fill
3944 true, // is_default_stack_executable
3945 true, // can_icf_inline_merge_sections
3947 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
3948 0x20000, // default_text_segment_address
3949 0x10000, // abi_pagesize (overridable by -z max-page-size)
3950 0x10000, // common_pagesize (overridable by -z common-page-size)
3951 true, // isolate_execinstr
3952 0x10000000, // rosegment_gap
3953 elfcpp::SHN_UNDEF, // small_common_shndx
3954 elfcpp::SHN_UNDEF, // large_common_shndx
3955 0, // small_common_section_flags
3956 0, // large_common_section_flags
3957 NULL, // attributes_section
3958 NULL // attributes_vendor
3961 #define NACLMASK 0xe0 // 32-byte alignment mask
3964 Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
3966 0xff, 0x35, // pushl contents of memory address
3967 0, 0, 0, 0, // replaced with address of .got + 4
3968 0x8b, 0x0d, // movl contents of address, %ecx
3969 0, 0, 0, 0, // replaced with address of .got + 8
3970 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
3971 0xff, 0xe1, // jmp *%ecx
3972 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3973 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3974 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3975 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3976 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3977 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3978 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3979 0x90, 0x90, 0x90, 0x90, 0x90
3983 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
3985 elfcpp::Elf_types<32>::Elf_Addr got_address)
3987 memcpy(pov, first_plt_entry, plt_entry_size);
3988 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
3989 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
3992 // The first entry in the PLT for a shared object.
3995 Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
3997 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
3998 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
3999 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4000 0xff, 0xe1, // jmp *%ecx
4001 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4002 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4003 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4004 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4005 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4006 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4007 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4008 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4009 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4010 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4014 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4016 elfcpp::Elf_types<32>::Elf_Addr)
4018 memcpy(pov, first_plt_entry, plt_entry_size);
4021 // Subsequent entries in the PLT for an executable.
4024 Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
4026 0x8b, 0x0d, // movl contents of address, %ecx */
4027 0, 0, 0, 0, // replaced with address of symbol in .got
4028 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4029 0xff, 0xe1, // jmp *%ecx
4031 // Pad to the next 32-byte boundary with nop instructions.
4033 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4034 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4036 // Lazy GOT entries point here (32-byte aligned).
4037 0x68, // pushl immediate
4038 0, 0, 0, 0, // replaced with offset into relocation table
4039 0xe9, // jmp relative
4040 0, 0, 0, 0, // replaced with offset to start of .plt
4042 // Pad to the next 32-byte boundary with nop instructions.
4043 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4044 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4049 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4051 elfcpp::Elf_types<32>::Elf_Addr got_address,
4052 unsigned int got_offset,
4053 unsigned int plt_offset,
4054 unsigned int plt_rel_offset)
4056 memcpy(pov, plt_entry, plt_entry_size);
4057 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4058 got_address + got_offset);
4059 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4060 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4064 // Subsequent entries in the PLT for a shared object.
4067 Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
4069 0x8b, 0x8b, // movl offset(%ebx), %ecx
4070 0, 0, 0, 0, // replaced with offset of symbol in .got
4071 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4072 0xff, 0xe1, // jmp *%ecx
4074 // Pad to the next 32-byte boundary with nop instructions.
4076 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4077 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4079 // Lazy GOT entries point here (32-byte aligned).
4080 0x68, // pushl immediate
4081 0, 0, 0, 0, // replaced with offset into relocation table.
4082 0xe9, // jmp relative
4083 0, 0, 0, 0, // replaced with offset to start of .plt.
4085 // Pad to the next 32-byte boundary with nop instructions.
4086 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4087 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4092 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4094 elfcpp::Elf_types<32>::Elf_Addr,
4095 unsigned int got_offset,
4096 unsigned int plt_offset,
4097 unsigned int plt_rel_offset)
4099 memcpy(pov, plt_entry, plt_entry_size);
4100 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
4101 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4102 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4107 Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4109 0, 0, 0, 0, // Replaced with offset to .plt.
4110 0, 0, 0, 0, // Replaced with size of .plt.
4111 0, // Augmentation size.
4112 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
4113 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4114 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
4115 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4116 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4117 13, // Block length.
4118 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
4119 elfcpp::DW_OP_breg8, 0, // Push %eip.
4120 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4121 elfcpp::DW_OP_and, // & (%eip & 0x3f).
4122 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4123 elfcpp::DW_OP_ge, // >= ((%eip & 0x3f) >= 0x25)
4124 elfcpp::DW_OP_lit2, // Push 2.
4125 elfcpp::DW_OP_shl, // << (((%eip & 0x3f) >= 0x25) << 2)
4126 elfcpp::DW_OP_plus, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4127 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4131 // The selector for i386-nacl object files.
4133 class Target_selector_i386_nacl
4134 : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
4137 Target_selector_i386_nacl()
4138 : Target_selector_nacl<Target_selector_i386,
4139 Target_i386_nacl>("x86-32",
4145 Target_selector_i386_nacl target_selector_i386;
4147 } // End anonymous namespace.