1 // i386.cc -- i386 target support for gold.
3 // Copyright (C) 2006-2015 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
50 // A class to handle the .got.plt section.
52 class Output_data_got_plt_i386 : public Output_section_data_build
55 Output_data_got_plt_i386(Layout* layout)
56 : Output_section_data_build(4),
61 // Write out the PLT data.
63 do_write(Output_file*);
65 // Write to a map file.
67 do_print_to_mapfile(Mapfile* mapfile) const
68 { mapfile->print_output_data(this, "** GOT PLT"); }
71 // A pointer to the Layout class, so that we can find the .dynamic
72 // section when we write out the GOT PLT section.
76 // A class to handle the PLT data.
77 // This is an abstract base class that handles most of the linker details
78 // but does not know the actual contents of PLT entries. The derived
79 // classes below fill in those details.
81 class Output_data_plt_i386 : public Output_section_data
84 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
86 Output_data_plt_i386(Layout*, uint64_t addralign,
87 Output_data_got_plt_i386*, Output_data_space*);
89 // Add an entry to the PLT.
91 add_entry(Symbol_table*, Layout*, Symbol* gsym);
93 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
95 add_local_ifunc_entry(Symbol_table*, Layout*,
96 Sized_relobj_file<32, false>* relobj,
97 unsigned int local_sym_index);
99 // Return the .rel.plt section data.
102 { return this->rel_; }
104 // Return where the TLS_DESC relocations should go.
106 rel_tls_desc(Layout*);
108 // Return where the IRELATIVE relocations should go.
110 rel_irelative(Symbol_table*, Layout*);
112 // Return whether we created a section for IRELATIVE relocations.
114 has_irelative_section() const
115 { return this->irelative_rel_ != NULL; }
117 // Return the number of PLT entries.
120 { return this->count_ + this->irelative_count_; }
122 // Return the offset of the first non-reserved PLT entry.
124 first_plt_entry_offset()
125 { return this->get_plt_entry_size(); }
127 // Return the size of a PLT entry.
129 get_plt_entry_size() const
130 { return this->do_get_plt_entry_size(); }
132 // Return the PLT address to use for a global symbol.
134 address_for_global(const Symbol*);
136 // Return the PLT address to use for a local symbol.
138 address_for_local(const Relobj*, unsigned int symndx);
140 // Add .eh_frame information for the PLT.
142 add_eh_frame(Layout* layout)
143 { this->do_add_eh_frame(layout); }
146 // Fill the first PLT entry, given the pointer to the PLT section data
147 // and the runtime address of the GOT.
149 fill_first_plt_entry(unsigned char* pov,
150 elfcpp::Elf_types<32>::Elf_Addr got_address)
151 { this->do_fill_first_plt_entry(pov, got_address); }
153 // Fill a normal PLT entry, given the pointer to the entry's data in the
154 // section, the runtime address of the GOT, the offset into the GOT of
155 // the corresponding slot, the offset into the relocation section of the
156 // corresponding reloc, and the offset of this entry within the whole
157 // PLT. Return the offset from this PLT entry's runtime address that
158 // should be used to compute the initial value of the GOT slot.
160 fill_plt_entry(unsigned char* pov,
161 elfcpp::Elf_types<32>::Elf_Addr got_address,
162 unsigned int got_offset,
163 unsigned int plt_offset,
164 unsigned int plt_rel_offset)
166 return this->do_fill_plt_entry(pov, got_address, got_offset,
167 plt_offset, plt_rel_offset);
171 do_get_plt_entry_size() const = 0;
174 do_fill_first_plt_entry(unsigned char* pov,
175 elfcpp::Elf_types<32>::Elf_Addr got_address) = 0;
178 do_fill_plt_entry(unsigned char* pov,
179 elfcpp::Elf_types<32>::Elf_Addr got_address,
180 unsigned int got_offset,
181 unsigned int plt_offset,
182 unsigned int plt_rel_offset) = 0;
185 do_add_eh_frame(Layout*) = 0;
188 do_adjust_output_section(Output_section* os);
190 // Write to a map file.
192 do_print_to_mapfile(Mapfile* mapfile) const
193 { mapfile->print_output_data(this, _("** PLT")); }
195 // The .eh_frame unwind information for the PLT.
196 // The CIE is common across variants of the PLT format.
197 static const int plt_eh_frame_cie_size = 16;
198 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
201 // Set the final size.
203 set_final_data_size()
205 this->set_data_size((this->count_ + this->irelative_count_ + 1)
206 * this->get_plt_entry_size());
209 // Write out the PLT data.
211 do_write(Output_file*);
213 // We keep a list of global STT_GNU_IFUNC symbols, each with its
214 // offset in the GOT.
218 unsigned int got_offset;
221 // We keep a list of local STT_GNU_IFUNC symbols, each with its
222 // offset in the GOT.
225 Sized_relobj_file<32, false>* object;
226 unsigned int local_sym_index;
227 unsigned int got_offset;
230 // The reloc section.
232 // The TLS_DESC relocations, if necessary. These must follow the
233 // regular PLT relocs.
234 Reloc_section* tls_desc_rel_;
235 // The IRELATIVE relocations, if necessary. These must follow the
236 // regular relocatoins and the TLS_DESC relocations.
237 Reloc_section* irelative_rel_;
238 // The .got.plt section.
239 Output_data_got_plt_i386* got_plt_;
240 // The part of the .got.plt section used for IRELATIVE relocs.
241 Output_data_space* got_irelative_;
242 // The number of PLT entries.
244 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
245 // the regular PLT entries.
246 unsigned int irelative_count_;
247 // Global STT_GNU_IFUNC symbols.
248 std::vector<Global_ifunc> global_ifuncs_;
249 // Local STT_GNU_IFUNC symbols.
250 std::vector<Local_ifunc> local_ifuncs_;
253 // This is an abstract class for the standard PLT layout.
254 // The derived classes below handle the actual PLT contents
255 // for the executable (non-PIC) and shared-library (PIC) cases.
256 // The unwind information is uniform across those two, so it's here.
258 class Output_data_plt_i386_standard : public Output_data_plt_i386
261 Output_data_plt_i386_standard(Layout* layout,
262 Output_data_got_plt_i386* got_plt,
263 Output_data_space* got_irelative)
264 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
269 do_get_plt_entry_size() const
270 { return plt_entry_size; }
273 do_add_eh_frame(Layout* layout)
275 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
276 plt_eh_frame_fde, plt_eh_frame_fde_size);
279 // The size of an entry in the PLT.
280 static const int plt_entry_size = 16;
282 // The .eh_frame unwind information for the PLT.
283 static const int plt_eh_frame_fde_size = 32;
284 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
287 // Actually fill the PLT contents for an executable (non-PIC).
289 class Output_data_plt_i386_exec : public Output_data_plt_i386_standard
292 Output_data_plt_i386_exec(Layout* layout,
293 Output_data_got_plt_i386* got_plt,
294 Output_data_space* got_irelative)
295 : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
300 do_fill_first_plt_entry(unsigned char* pov,
301 elfcpp::Elf_types<32>::Elf_Addr got_address);
304 do_fill_plt_entry(unsigned char* pov,
305 elfcpp::Elf_types<32>::Elf_Addr got_address,
306 unsigned int got_offset,
307 unsigned int plt_offset,
308 unsigned int plt_rel_offset);
311 // The first entry in the PLT for an executable.
312 static const unsigned char first_plt_entry[plt_entry_size];
314 // Other entries in the PLT for an executable.
315 static const unsigned char plt_entry[plt_entry_size];
318 // Actually fill the PLT contents for a shared library (PIC).
320 class Output_data_plt_i386_dyn : public Output_data_plt_i386_standard
323 Output_data_plt_i386_dyn(Layout* layout,
324 Output_data_got_plt_i386* got_plt,
325 Output_data_space* got_irelative)
326 : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
331 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
334 do_fill_plt_entry(unsigned char* pov,
335 elfcpp::Elf_types<32>::Elf_Addr,
336 unsigned int got_offset,
337 unsigned int plt_offset,
338 unsigned int plt_rel_offset);
341 // The first entry in the PLT for a shared object.
342 static const unsigned char first_plt_entry[plt_entry_size];
344 // Other entries in the PLT for a shared object.
345 static const unsigned char plt_entry[plt_entry_size];
348 // The i386 target class.
349 // TLS info comes from
350 // http://people.redhat.com/drepper/tls.pdf
351 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
353 class Target_i386 : public Sized_target<32, false>
356 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
358 Target_i386(const Target::Target_info* info = &i386_info)
359 : Sized_target<32, false>(info),
360 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
361 got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
362 rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY),
363 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
366 // Process the relocations to determine unreferenced sections for
367 // garbage collection.
369 gc_process_relocs(Symbol_table* symtab,
371 Sized_relobj_file<32, false>* object,
372 unsigned int data_shndx,
373 unsigned int sh_type,
374 const unsigned char* prelocs,
376 Output_section* output_section,
377 bool needs_special_offset_handling,
378 size_t local_symbol_count,
379 const unsigned char* plocal_symbols);
381 // Scan the relocations to look for symbol adjustments.
383 scan_relocs(Symbol_table* symtab,
385 Sized_relobj_file<32, false>* object,
386 unsigned int data_shndx,
387 unsigned int sh_type,
388 const unsigned char* prelocs,
390 Output_section* output_section,
391 bool needs_special_offset_handling,
392 size_t local_symbol_count,
393 const unsigned char* plocal_symbols);
395 // Finalize the sections.
397 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
399 // Return the value to use for a dynamic which requires special
402 do_dynsym_value(const Symbol*) const;
404 // Relocate a section.
406 relocate_section(const Relocate_info<32, false>*,
407 unsigned int sh_type,
408 const unsigned char* prelocs,
410 Output_section* output_section,
411 bool needs_special_offset_handling,
413 elfcpp::Elf_types<32>::Elf_Addr view_address,
414 section_size_type view_size,
415 const Reloc_symbol_changes*);
417 // Scan the relocs during a relocatable link.
419 scan_relocatable_relocs(Symbol_table* symtab,
421 Sized_relobj_file<32, false>* object,
422 unsigned int data_shndx,
423 unsigned int sh_type,
424 const unsigned char* prelocs,
426 Output_section* output_section,
427 bool needs_special_offset_handling,
428 size_t local_symbol_count,
429 const unsigned char* plocal_symbols,
430 Relocatable_relocs*);
432 // Emit relocations for a section.
434 relocate_relocs(const Relocate_info<32, false>*,
435 unsigned int sh_type,
436 const unsigned char* prelocs,
438 Output_section* output_section,
439 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
440 const Relocatable_relocs*,
442 elfcpp::Elf_types<32>::Elf_Addr view_address,
443 section_size_type view_size,
444 unsigned char* reloc_view,
445 section_size_type reloc_view_size);
447 // Return a string used to fill a code section with nops.
449 do_code_fill(section_size_type length) const;
451 // Return whether SYM is defined by the ABI.
453 do_is_defined_by_abi(const Symbol* sym) const
454 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
456 // Return whether a symbol name implies a local label. The UnixWare
457 // 2.1 cc generates temporary symbols that start with .X, so we
458 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
459 // If so, we should move the .X recognition into
460 // Target::do_is_local_label_name.
462 do_is_local_label_name(const char* name) const
464 if (name[0] == '.' && name[1] == 'X')
466 return Target::do_is_local_label_name(name);
469 // Return the PLT address to use for a global symbol.
471 do_plt_address_for_global(const Symbol* gsym) const
472 { return this->plt_section()->address_for_global(gsym); }
475 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
476 { return this->plt_section()->address_for_local(relobj, symndx); }
478 // We can tell whether we take the address of a function.
480 do_can_check_for_function_pointers() const
483 // Return the base for a DW_EH_PE_datarel encoding.
485 do_ehframe_datarel_base() const;
487 // Return whether SYM is call to a non-split function.
489 do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
491 // Adjust -fsplit-stack code which calls non-split-stack code.
493 do_calls_non_split(Relobj* object, unsigned int shndx,
494 section_offset_type fnoffset, section_size_type fnsize,
495 unsigned char* view, section_size_type view_size,
496 std::string* from, std::string* to) const;
498 // Return the size of the GOT section.
502 gold_assert(this->got_ != NULL);
503 return this->got_->data_size();
506 // Return the number of entries in the GOT.
508 got_entry_count() const
510 if (this->got_ == NULL)
512 return this->got_size() / 4;
515 // Return the number of entries in the PLT.
517 plt_entry_count() const;
519 // Return the offset of the first non-reserved PLT entry.
521 first_plt_entry_offset() const;
523 // Return the size of each PLT entry.
525 plt_entry_size() const;
528 // Instantiate the plt_ member.
529 // This chooses the right PLT flavor for an executable or a shared object.
530 Output_data_plt_i386*
531 make_data_plt(Layout* layout,
532 Output_data_got_plt_i386* got_plt,
533 Output_data_space* got_irelative,
535 { return this->do_make_data_plt(layout, got_plt, got_irelative, dyn); }
537 virtual Output_data_plt_i386*
538 do_make_data_plt(Layout* layout,
539 Output_data_got_plt_i386* got_plt,
540 Output_data_space* got_irelative,
544 return new Output_data_plt_i386_dyn(layout, got_plt, got_irelative);
546 return new Output_data_plt_i386_exec(layout, got_plt, got_irelative);
550 // The class which scans relocations.
555 get_reference_flags(unsigned int r_type);
558 local(Symbol_table* symtab, Layout* layout, Target_i386* target,
559 Sized_relobj_file<32, false>* object,
560 unsigned int data_shndx,
561 Output_section* output_section,
562 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
563 const elfcpp::Sym<32, false>& lsym,
567 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
568 Sized_relobj_file<32, false>* object,
569 unsigned int data_shndx,
570 Output_section* output_section,
571 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
575 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
577 Sized_relobj_file<32, false>* object,
578 unsigned int data_shndx,
579 Output_section* output_section,
580 const elfcpp::Rel<32, false>& reloc,
582 const elfcpp::Sym<32, false>& lsym);
585 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
587 Sized_relobj_file<32, false>* object,
588 unsigned int data_shndx,
589 Output_section* output_section,
590 const elfcpp::Rel<32, false>& reloc,
595 possible_function_pointer_reloc(unsigned int r_type);
598 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
599 unsigned int r_type);
602 unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
605 unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
609 // The class which implements relocation.
614 : skip_call_tls_get_addr_(false),
615 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
620 if (this->skip_call_tls_get_addr_)
622 // FIXME: This needs to specify the location somehow.
623 gold_error(_("missing expected TLS relocation"));
627 // Return whether the static relocation needs to be applied.
629 should_apply_static_reloc(const Sized_symbol<32>* gsym,
632 Output_section* output_section);
634 // Do a relocation. Return false if the caller should not issue
635 // any warnings about this relocation.
637 relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
638 size_t relnum, const elfcpp::Rel<32, false>&,
639 unsigned int r_type, const Sized_symbol<32>*,
640 const Symbol_value<32>*,
641 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
645 // Do a TLS relocation.
647 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
648 size_t relnum, const elfcpp::Rel<32, false>&,
649 unsigned int r_type, const Sized_symbol<32>*,
650 const Symbol_value<32>*,
651 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
654 // Do a TLS General-Dynamic to Initial-Exec transition.
656 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
657 Output_segment* tls_segment,
658 const elfcpp::Rel<32, false>&, unsigned int r_type,
659 elfcpp::Elf_types<32>::Elf_Addr value,
661 section_size_type view_size);
663 // Do a TLS General-Dynamic to Local-Exec transition.
665 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
666 Output_segment* tls_segment,
667 const elfcpp::Rel<32, false>&, unsigned int r_type,
668 elfcpp::Elf_types<32>::Elf_Addr value,
670 section_size_type view_size);
672 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
675 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
676 Output_segment* tls_segment,
677 const elfcpp::Rel<32, false>&, unsigned int r_type,
678 elfcpp::Elf_types<32>::Elf_Addr value,
680 section_size_type view_size);
682 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
685 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
686 Output_segment* tls_segment,
687 const elfcpp::Rel<32, false>&, unsigned int r_type,
688 elfcpp::Elf_types<32>::Elf_Addr value,
690 section_size_type view_size);
692 // Do a TLS Local-Dynamic to Local-Exec transition.
694 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
695 Output_segment* tls_segment,
696 const elfcpp::Rel<32, false>&, unsigned int r_type,
697 elfcpp::Elf_types<32>::Elf_Addr value,
699 section_size_type view_size);
701 // Do a TLS Initial-Exec to Local-Exec transition.
703 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
704 Output_segment* tls_segment,
705 const elfcpp::Rel<32, false>&, unsigned int r_type,
706 elfcpp::Elf_types<32>::Elf_Addr value,
708 section_size_type view_size);
710 // We need to keep track of which type of local dynamic relocation
711 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
712 enum Local_dynamic_type
719 // This is set if we should skip the next reloc, which should be a
720 // PLT32 reloc against ___tls_get_addr.
721 bool skip_call_tls_get_addr_;
722 // The type of local dynamic relocation we have seen in the section
723 // being relocated, if any.
724 Local_dynamic_type local_dynamic_type_;
727 // A class which returns the size required for a relocation type,
728 // used while scanning relocs during a relocatable link.
729 class Relocatable_size_for_reloc
733 get_size_for_reloc(unsigned int, Relobj*);
736 // Adjust TLS relocation type based on the options and whether this
737 // is a local symbol.
738 static tls::Tls_optimization
739 optimize_tls_reloc(bool is_final, int r_type);
741 // Check if relocation against this symbol is a candidate for
743 // mov foo@GOT(%reg), %reg
745 // lea foo@GOTOFF(%reg), %reg.
747 can_convert_mov_to_lea(const Symbol* gsym)
749 gold_assert(gsym != NULL);
750 return (gsym->type() != elfcpp::STT_GNU_IFUNC
751 && !gsym->is_undefined ()
752 && !gsym->is_from_dynobj()
753 && !gsym->is_preemptible()
754 && (!parameters->options().shared()
755 || (gsym->visibility() != elfcpp::STV_DEFAULT
756 && gsym->visibility() != elfcpp::STV_PROTECTED)
757 || parameters->options().Bsymbolic())
758 && strcmp(gsym->name(), "_DYNAMIC") != 0);
761 // Get the GOT section, creating it if necessary.
762 Output_data_got<32, false>*
763 got_section(Symbol_table*, Layout*);
765 // Get the GOT PLT section.
766 Output_data_got_plt_i386*
767 got_plt_section() const
769 gold_assert(this->got_plt_ != NULL);
770 return this->got_plt_;
773 // Get the GOT section for TLSDESC entries.
774 Output_data_got<32, false>*
775 got_tlsdesc_section() const
777 gold_assert(this->got_tlsdesc_ != NULL);
778 return this->got_tlsdesc_;
781 // Create the PLT section.
783 make_plt_section(Symbol_table* symtab, Layout* layout);
785 // Create a PLT entry for a global symbol.
787 make_plt_entry(Symbol_table*, Layout*, Symbol*);
789 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
791 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
792 Sized_relobj_file<32, false>* relobj,
793 unsigned int local_sym_index);
795 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
797 define_tls_base_symbol(Symbol_table*, Layout*);
799 // Create a GOT entry for the TLS module index.
801 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
802 Sized_relobj_file<32, false>* object);
804 // Get the PLT section.
805 Output_data_plt_i386*
808 gold_assert(this->plt_ != NULL);
812 // Get the dynamic reloc section, creating it if necessary.
814 rel_dyn_section(Layout*);
816 // Get the section to use for TLS_DESC relocations.
818 rel_tls_desc_section(Layout*) const;
820 // Get the section to use for IRELATIVE relocations.
822 rel_irelative_section(Layout*);
824 // Add a potential copy relocation.
826 copy_reloc(Symbol_table* symtab, Layout* layout,
827 Sized_relobj_file<32, false>* object,
828 unsigned int shndx, Output_section* output_section,
829 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
831 unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
832 this->copy_relocs_.copy_reloc(symtab, layout,
833 symtab->get_sized_symbol<32>(sym),
834 object, shndx, output_section,
835 r_type, reloc.get_r_offset(), 0,
836 this->rel_dyn_section(layout));
839 // Information about this specific target which we pass to the
840 // general Target structure.
841 static const Target::Target_info i386_info;
843 // The types of GOT entries needed for this platform.
844 // These values are exposed to the ABI in an incremental link.
845 // Do not renumber existing values without changing the version
846 // number of the .gnu_incremental_inputs section.
849 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
850 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
851 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
852 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
853 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
857 Output_data_got<32, false>* got_;
859 Output_data_plt_i386* plt_;
860 // The GOT PLT section.
861 Output_data_got_plt_i386* got_plt_;
862 // The GOT section for IRELATIVE relocations.
863 Output_data_space* got_irelative_;
864 // The GOT section for TLSDESC relocations.
865 Output_data_got<32, false>* got_tlsdesc_;
866 // The _GLOBAL_OFFSET_TABLE_ symbol.
867 Symbol* global_offset_table_;
868 // The dynamic reloc section.
869 Reloc_section* rel_dyn_;
870 // The section to use for IRELATIVE relocs.
871 Reloc_section* rel_irelative_;
872 // Relocs saved to avoid a COPY reloc.
873 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
874 // Offset of the GOT entry for the TLS module index.
875 unsigned int got_mod_index_offset_;
876 // True if the _TLS_MODULE_BASE_ symbol has been defined.
877 bool tls_base_symbol_defined_;
880 const Target::Target_info Target_i386::i386_info =
883 false, // is_big_endian
884 elfcpp::EM_386, // machine_code
885 false, // has_make_symbol
886 false, // has_resolve
887 true, // has_code_fill
888 true, // is_default_stack_executable
889 true, // can_icf_inline_merge_sections
891 "/usr/lib/libc.so.1", // dynamic_linker
892 0x08048000, // default_text_segment_address
893 0x1000, // abi_pagesize (overridable by -z max-page-size)
894 0x1000, // common_pagesize (overridable by -z common-page-size)
895 false, // isolate_execinstr
897 elfcpp::SHN_UNDEF, // small_common_shndx
898 elfcpp::SHN_UNDEF, // large_common_shndx
899 0, // small_common_section_flags
900 0, // large_common_section_flags
901 NULL, // attributes_section
902 NULL, // attributes_vendor
903 "_start", // entry_symbol_name
904 32, // hash_entry_size
907 // Get the GOT section, creating it if necessary.
909 Output_data_got<32, false>*
910 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
912 if (this->got_ == NULL)
914 gold_assert(symtab != NULL && layout != NULL);
916 this->got_ = new Output_data_got<32, false>();
918 // When using -z now, we can treat .got.plt as a relro section.
919 // Without -z now, it is modified after program startup by lazy
921 bool is_got_plt_relro = parameters->options().now();
922 Output_section_order got_order = (is_got_plt_relro
925 Output_section_order got_plt_order = (is_got_plt_relro
927 : ORDER_NON_RELRO_FIRST);
929 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
931 | elfcpp::SHF_WRITE),
932 this->got_, got_order, true);
934 this->got_plt_ = new Output_data_got_plt_i386(layout);
935 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
937 | elfcpp::SHF_WRITE),
938 this->got_plt_, got_plt_order,
941 // The first three entries are reserved.
942 this->got_plt_->set_current_data_size(3 * 4);
944 if (!is_got_plt_relro)
946 // Those bytes can go into the relro segment.
947 layout->increase_relro(3 * 4);
950 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
951 this->global_offset_table_ =
952 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
953 Symbol_table::PREDEFINED,
955 0, 0, elfcpp::STT_OBJECT,
957 elfcpp::STV_HIDDEN, 0,
960 // If there are any IRELATIVE relocations, they get GOT entries
961 // in .got.plt after the jump slot relocations.
962 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
963 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
965 | elfcpp::SHF_WRITE),
966 this->got_irelative_,
967 got_plt_order, is_got_plt_relro);
969 // If there are any TLSDESC relocations, they get GOT entries in
970 // .got.plt after the jump slot entries.
971 this->got_tlsdesc_ = new Output_data_got<32, false>();
972 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
974 | elfcpp::SHF_WRITE),
976 got_plt_order, is_got_plt_relro);
982 // Get the dynamic reloc section, creating it if necessary.
984 Target_i386::Reloc_section*
985 Target_i386::rel_dyn_section(Layout* layout)
987 if (this->rel_dyn_ == NULL)
989 gold_assert(layout != NULL);
990 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
991 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
992 elfcpp::SHF_ALLOC, this->rel_dyn_,
993 ORDER_DYNAMIC_RELOCS, false);
995 return this->rel_dyn_;
998 // Get the section to use for IRELATIVE relocs, creating it if
999 // necessary. These go in .rel.dyn, but only after all other dynamic
1000 // relocations. They need to follow the other dynamic relocations so
1001 // that they can refer to global variables initialized by those
1004 Target_i386::Reloc_section*
1005 Target_i386::rel_irelative_section(Layout* layout)
1007 if (this->rel_irelative_ == NULL)
1009 // Make sure we have already create the dynamic reloc section.
1010 this->rel_dyn_section(layout);
1011 this->rel_irelative_ = new Reloc_section(false);
1012 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1013 elfcpp::SHF_ALLOC, this->rel_irelative_,
1014 ORDER_DYNAMIC_RELOCS, false);
1015 gold_assert(this->rel_dyn_->output_section()
1016 == this->rel_irelative_->output_section());
1018 return this->rel_irelative_;
1021 // Write the first three reserved words of the .got.plt section.
1022 // The remainder of the section is written while writing the PLT
1023 // in Output_data_plt_i386::do_write.
1026 Output_data_got_plt_i386::do_write(Output_file* of)
1028 // The first entry in the GOT is the address of the .dynamic section
1029 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1030 // We saved space for them when we created the section in
1031 // Target_i386::got_section.
1032 const off_t got_file_offset = this->offset();
1033 gold_assert(this->data_size() >= 12);
1034 unsigned char* const got_view = of->get_output_view(got_file_offset, 12);
1035 Output_section* dynamic = this->layout_->dynamic_section();
1036 uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1037 elfcpp::Swap<32, false>::writeval(got_view, dynamic_addr);
1038 memset(got_view + 4, 0, 8);
1039 of->write_output_view(got_file_offset, 12, got_view);
1042 // Create the PLT section. The ordinary .got section is an argument,
1043 // since we need to refer to the start. We also create our own .got
1044 // section just for PLT entries.
1046 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
1048 Output_data_got_plt_i386* got_plt,
1049 Output_data_space* got_irelative)
1050 : Output_section_data(addralign),
1051 tls_desc_rel_(NULL), irelative_rel_(NULL), got_plt_(got_plt),
1052 got_irelative_(got_irelative), count_(0), irelative_count_(0),
1053 global_ifuncs_(), local_ifuncs_()
1055 this->rel_ = new Reloc_section(false);
1056 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1057 elfcpp::SHF_ALLOC, this->rel_,
1058 ORDER_DYNAMIC_PLT_RELOCS, false);
1062 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
1064 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1065 // linker, and so do we.
1069 // Add an entry to the PLT.
1072 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
1075 gold_assert(!gsym->has_plt_offset());
1077 // Every PLT entry needs a reloc.
1078 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1079 && gsym->can_use_relative_reloc(false))
1081 gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
1082 ++this->irelative_count_;
1083 section_offset_type got_offset =
1084 this->got_irelative_->current_data_size();
1085 this->got_irelative_->set_current_data_size(got_offset + 4);
1086 Reloc_section* rel = this->rel_irelative(symtab, layout);
1087 rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
1088 this->got_irelative_, got_offset);
1089 struct Global_ifunc gi;
1091 gi.got_offset = got_offset;
1092 this->global_ifuncs_.push_back(gi);
1096 // When setting the PLT offset we skip the initial reserved PLT
1098 gsym->set_plt_offset((this->count_ + 1) * this->get_plt_entry_size());
1102 section_offset_type got_offset = this->got_plt_->current_data_size();
1104 // Every PLT entry needs a GOT entry which points back to the
1105 // PLT entry (this will be changed by the dynamic linker,
1106 // normally lazily when the function is called).
1107 this->got_plt_->set_current_data_size(got_offset + 4);
1109 gsym->set_needs_dynsym_entry();
1110 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
1114 // Note that we don't need to save the symbol. The contents of the
1115 // PLT are independent of which symbols are used. The symbols only
1116 // appear in the relocations.
1119 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1123 Output_data_plt_i386::add_local_ifunc_entry(
1124 Symbol_table* symtab,
1126 Sized_relobj_file<32, false>* relobj,
1127 unsigned int local_sym_index)
1129 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1130 ++this->irelative_count_;
1132 section_offset_type got_offset = this->got_irelative_->current_data_size();
1134 // Every PLT entry needs a GOT entry which points back to the PLT
1136 this->got_irelative_->set_current_data_size(got_offset + 4);
1138 // Every PLT entry needs a reloc.
1139 Reloc_section* rel = this->rel_irelative(symtab, layout);
1140 rel->add_symbolless_local_addend(relobj, local_sym_index,
1141 elfcpp::R_386_IRELATIVE,
1142 this->got_irelative_, got_offset);
1144 struct Local_ifunc li;
1146 li.local_sym_index = local_sym_index;
1147 li.got_offset = got_offset;
1148 this->local_ifuncs_.push_back(li);
1153 // Return where the TLS_DESC relocations should go, creating it if
1154 // necessary. These follow the JUMP_SLOT relocations.
1156 Output_data_plt_i386::Reloc_section*
1157 Output_data_plt_i386::rel_tls_desc(Layout* layout)
1159 if (this->tls_desc_rel_ == NULL)
1161 this->tls_desc_rel_ = new Reloc_section(false);
1162 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1163 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
1164 ORDER_DYNAMIC_PLT_RELOCS, false);
1165 gold_assert(this->tls_desc_rel_->output_section()
1166 == this->rel_->output_section());
1168 return this->tls_desc_rel_;
1171 // Return where the IRELATIVE relocations should go in the PLT. These
1172 // follow the JUMP_SLOT and TLS_DESC relocations.
1174 Output_data_plt_i386::Reloc_section*
1175 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
1177 if (this->irelative_rel_ == NULL)
1179 // Make sure we have a place for the TLS_DESC relocations, in
1180 // case we see any later on.
1181 this->rel_tls_desc(layout);
1182 this->irelative_rel_ = new Reloc_section(false);
1183 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1184 elfcpp::SHF_ALLOC, this->irelative_rel_,
1185 ORDER_DYNAMIC_PLT_RELOCS, false);
1186 gold_assert(this->irelative_rel_->output_section()
1187 == this->rel_->output_section());
1189 if (parameters->doing_static_link())
1191 // A statically linked executable will only have a .rel.plt
1192 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1193 // symbols. The library will use these symbols to locate
1194 // the IRELATIVE relocs at program startup time.
1195 symtab->define_in_output_data("__rel_iplt_start", NULL,
1196 Symbol_table::PREDEFINED,
1197 this->irelative_rel_, 0, 0,
1198 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1199 elfcpp::STV_HIDDEN, 0, false, true);
1200 symtab->define_in_output_data("__rel_iplt_end", NULL,
1201 Symbol_table::PREDEFINED,
1202 this->irelative_rel_, 0, 0,
1203 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1204 elfcpp::STV_HIDDEN, 0, true, true);
1207 return this->irelative_rel_;
1210 // Return the PLT address to use for a global symbol.
1213 Output_data_plt_i386::address_for_global(const Symbol* gsym)
1215 uint64_t offset = 0;
1216 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1217 && gsym->can_use_relative_reloc(false))
1218 offset = (this->count_ + 1) * this->get_plt_entry_size();
1219 return this->address() + offset + gsym->plt_offset();
1222 // Return the PLT address to use for a local symbol. These are always
1223 // IRELATIVE relocs.
1226 Output_data_plt_i386::address_for_local(const Relobj* object,
1229 return (this->address()
1230 + (this->count_ + 1) * this->get_plt_entry_size()
1231 + object->local_plt_offset(r_sym));
1234 // The first entry in the PLT for an executable.
1236 const unsigned char Output_data_plt_i386_exec::first_plt_entry[plt_entry_size] =
1238 0xff, 0x35, // pushl contents of memory address
1239 0, 0, 0, 0, // replaced with address of .got + 4
1240 0xff, 0x25, // jmp indirect
1241 0, 0, 0, 0, // replaced with address of .got + 8
1242 0, 0, 0, 0 // unused
1246 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1248 elfcpp::Elf_types<32>::Elf_Addr got_address)
1250 memcpy(pov, first_plt_entry, plt_entry_size);
1251 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1252 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1255 // The first entry in the PLT for a shared object.
1257 const unsigned char Output_data_plt_i386_dyn::first_plt_entry[plt_entry_size] =
1259 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1260 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1261 0, 0, 0, 0 // unused
1265 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1267 elfcpp::Elf_types<32>::Elf_Addr)
1269 memcpy(pov, first_plt_entry, plt_entry_size);
1272 // Subsequent entries in the PLT for an executable.
1274 const unsigned char Output_data_plt_i386_exec::plt_entry[plt_entry_size] =
1276 0xff, 0x25, // jmp indirect
1277 0, 0, 0, 0, // replaced with address of symbol in .got
1278 0x68, // pushl immediate
1279 0, 0, 0, 0, // replaced with offset into relocation table
1280 0xe9, // jmp relative
1281 0, 0, 0, 0 // replaced with offset to start of .plt
1285 Output_data_plt_i386_exec::do_fill_plt_entry(
1287 elfcpp::Elf_types<32>::Elf_Addr got_address,
1288 unsigned int got_offset,
1289 unsigned int plt_offset,
1290 unsigned int plt_rel_offset)
1292 memcpy(pov, plt_entry, plt_entry_size);
1293 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1294 got_address + got_offset);
1295 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1296 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1300 // Subsequent entries in the PLT for a shared object.
1302 const unsigned char Output_data_plt_i386_dyn::plt_entry[plt_entry_size] =
1304 0xff, 0xa3, // jmp *offset(%ebx)
1305 0, 0, 0, 0, // replaced with offset of symbol in .got
1306 0x68, // pushl immediate
1307 0, 0, 0, 0, // replaced with offset into relocation table
1308 0xe9, // jmp relative
1309 0, 0, 0, 0 // replaced with offset to start of .plt
1313 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
1314 elfcpp::Elf_types<32>::Elf_Addr,
1315 unsigned int got_offset,
1316 unsigned int plt_offset,
1317 unsigned int plt_rel_offset)
1319 memcpy(pov, plt_entry, plt_entry_size);
1320 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1321 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1322 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1326 // The .eh_frame unwind information for the PLT.
1329 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1332 'z', // Augmentation: augmentation size included.
1333 'R', // Augmentation: FDE encoding included.
1334 '\0', // End of augmentation string.
1335 1, // Code alignment factor.
1336 0x7c, // Data alignment factor.
1337 8, // Return address column.
1338 1, // Augmentation size.
1339 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1340 | elfcpp::DW_EH_PE_sdata4),
1341 elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1342 elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1343 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1348 Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1350 0, 0, 0, 0, // Replaced with offset to .plt.
1351 0, 0, 0, 0, // Replaced with size of .plt.
1352 0, // Augmentation size.
1353 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
1354 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1355 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
1356 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1357 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1358 11, // Block length.
1359 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
1360 elfcpp::DW_OP_breg8, 0, // Push %eip.
1361 elfcpp::DW_OP_lit15, // Push 0xf.
1362 elfcpp::DW_OP_and, // & (%eip & 0xf).
1363 elfcpp::DW_OP_lit11, // Push 0xb.
1364 elfcpp::DW_OP_ge, // >= ((%eip & 0xf) >= 0xb)
1365 elfcpp::DW_OP_lit2, // Push 2.
1366 elfcpp::DW_OP_shl, // << (((%eip & 0xf) >= 0xb) << 2)
1367 elfcpp::DW_OP_plus, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1368 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1374 // Write out the PLT. This uses the hand-coded instructions above,
1375 // and adjusts them as needed. This is all specified by the i386 ELF
1376 // Processor Supplement.
1379 Output_data_plt_i386::do_write(Output_file* of)
1381 const off_t offset = this->offset();
1382 const section_size_type oview_size =
1383 convert_to_section_size_type(this->data_size());
1384 unsigned char* const oview = of->get_output_view(offset, oview_size);
1386 const off_t got_file_offset = this->got_plt_->offset();
1387 gold_assert(parameters->incremental_update()
1388 || (got_file_offset + this->got_plt_->data_size()
1389 == this->got_irelative_->offset()));
1390 const section_size_type got_size =
1391 convert_to_section_size_type(this->got_plt_->data_size()
1392 + this->got_irelative_->data_size());
1394 unsigned char* const got_view = of->get_output_view(got_file_offset,
1397 unsigned char* pov = oview;
1399 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1400 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1402 this->fill_first_plt_entry(pov, got_address);
1403 pov += this->get_plt_entry_size();
1405 // The first three entries in the GOT are reserved, and are written
1406 // by Output_data_got_plt_i386::do_write.
1407 unsigned char* got_pov = got_view + 12;
1409 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1411 unsigned int plt_offset = this->get_plt_entry_size();
1412 unsigned int plt_rel_offset = 0;
1413 unsigned int got_offset = 12;
1414 const unsigned int count = this->count_ + this->irelative_count_;
1415 for (unsigned int i = 0;
1418 pov += this->get_plt_entry_size(),
1420 plt_offset += this->get_plt_entry_size(),
1421 plt_rel_offset += rel_size,
1424 // Set and adjust the PLT entry itself.
1425 unsigned int lazy_offset = this->fill_plt_entry(pov,
1431 // Set the entry in the GOT.
1432 elfcpp::Swap<32, false>::writeval(got_pov,
1433 plt_address + plt_offset + lazy_offset);
1436 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1437 // the GOT to point to the actual symbol value, rather than point to
1438 // the PLT entry. That will let the dynamic linker call the right
1439 // function when resolving IRELATIVE relocations.
1440 unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1441 for (std::vector<Global_ifunc>::const_iterator p =
1442 this->global_ifuncs_.begin();
1443 p != this->global_ifuncs_.end();
1446 const Sized_symbol<32>* ssym =
1447 static_cast<const Sized_symbol<32>*>(p->sym);
1448 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1452 for (std::vector<Local_ifunc>::const_iterator p =
1453 this->local_ifuncs_.begin();
1454 p != this->local_ifuncs_.end();
1457 const Symbol_value<32>* psymval =
1458 p->object->local_symbol(p->local_sym_index);
1459 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1460 psymval->value(p->object, 0));
1463 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1464 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1466 of->write_output_view(offset, oview_size, oview);
1467 of->write_output_view(got_file_offset, got_size, got_view);
1470 // Create the PLT section.
1473 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1475 if (this->plt_ == NULL)
1477 // Create the GOT sections first.
1478 this->got_section(symtab, layout);
1480 const bool dyn = parameters->options().output_is_position_independent();
1481 this->plt_ = this->make_data_plt(layout,
1483 this->got_irelative_,
1486 // Add unwind information if requested.
1487 if (parameters->options().ld_generated_unwind_info())
1488 this->plt_->add_eh_frame(layout);
1490 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1492 | elfcpp::SHF_EXECINSTR),
1493 this->plt_, ORDER_PLT, false);
1495 // Make the sh_info field of .rel.plt point to .plt.
1496 Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1497 rel_plt_os->set_info_section(this->plt_->output_section());
1501 // Create a PLT entry for a global symbol.
1504 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1506 if (gsym->has_plt_offset())
1508 if (this->plt_ == NULL)
1509 this->make_plt_section(symtab, layout);
1510 this->plt_->add_entry(symtab, layout, gsym);
1513 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1516 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1517 Sized_relobj_file<32, false>* relobj,
1518 unsigned int local_sym_index)
1520 if (relobj->local_has_plt_offset(local_sym_index))
1522 if (this->plt_ == NULL)
1523 this->make_plt_section(symtab, layout);
1524 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1527 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1530 // Return the number of entries in the PLT.
1533 Target_i386::plt_entry_count() const
1535 if (this->plt_ == NULL)
1537 return this->plt_->entry_count();
1540 // Return the offset of the first non-reserved PLT entry.
1543 Target_i386::first_plt_entry_offset() const
1545 return this->plt_->first_plt_entry_offset();
1548 // Return the size of each PLT entry.
1551 Target_i386::plt_entry_size() const
1553 return this->plt_->get_plt_entry_size();
1556 // Get the section to use for TLS_DESC relocations.
1558 Target_i386::Reloc_section*
1559 Target_i386::rel_tls_desc_section(Layout* layout) const
1561 return this->plt_section()->rel_tls_desc(layout);
1564 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1567 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1569 if (this->tls_base_symbol_defined_)
1572 Output_segment* tls_segment = layout->tls_segment();
1573 if (tls_segment != NULL)
1575 bool is_exec = parameters->options().output_is_executable();
1576 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1577 Symbol_table::PREDEFINED,
1581 elfcpp::STV_HIDDEN, 0,
1583 ? Symbol::SEGMENT_END
1584 : Symbol::SEGMENT_START),
1587 this->tls_base_symbol_defined_ = true;
1590 // Create a GOT entry for the TLS module index.
1593 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1594 Sized_relobj_file<32, false>* object)
1596 if (this->got_mod_index_offset_ == -1U)
1598 gold_assert(symtab != NULL && layout != NULL && object != NULL);
1599 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1600 Output_data_got<32, false>* got = this->got_section(symtab, layout);
1601 unsigned int got_offset = got->add_constant(0);
1602 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1604 got->add_constant(0);
1605 this->got_mod_index_offset_ = got_offset;
1607 return this->got_mod_index_offset_;
1610 // Optimize the TLS relocation type based on what we know about the
1611 // symbol. IS_FINAL is true if the final address of this symbol is
1612 // known at link time.
1614 tls::Tls_optimization
1615 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1617 // If we are generating a shared library, then we can't do anything
1619 if (parameters->options().shared())
1620 return tls::TLSOPT_NONE;
1624 case elfcpp::R_386_TLS_GD:
1625 case elfcpp::R_386_TLS_GOTDESC:
1626 case elfcpp::R_386_TLS_DESC_CALL:
1627 // These are General-Dynamic which permits fully general TLS
1628 // access. Since we know that we are generating an executable,
1629 // we can convert this to Initial-Exec. If we also know that
1630 // this is a local symbol, we can further switch to Local-Exec.
1632 return tls::TLSOPT_TO_LE;
1633 return tls::TLSOPT_TO_IE;
1635 case elfcpp::R_386_TLS_LDM:
1636 // This is Local-Dynamic, which refers to a local symbol in the
1637 // dynamic TLS block. Since we know that we generating an
1638 // executable, we can switch to Local-Exec.
1639 return tls::TLSOPT_TO_LE;
1641 case elfcpp::R_386_TLS_LDO_32:
1642 // Another type of Local-Dynamic relocation.
1643 return tls::TLSOPT_TO_LE;
1645 case elfcpp::R_386_TLS_IE:
1646 case elfcpp::R_386_TLS_GOTIE:
1647 case elfcpp::R_386_TLS_IE_32:
1648 // These are Initial-Exec relocs which get the thread offset
1649 // from the GOT. If we know that we are linking against the
1650 // local symbol, we can switch to Local-Exec, which links the
1651 // thread offset into the instruction.
1653 return tls::TLSOPT_TO_LE;
1654 return tls::TLSOPT_NONE;
1656 case elfcpp::R_386_TLS_LE:
1657 case elfcpp::R_386_TLS_LE_32:
1658 // When we already have Local-Exec, there is nothing further we
1660 return tls::TLSOPT_NONE;
1667 // Get the Reference_flags for a particular relocation.
1670 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1674 case elfcpp::R_386_NONE:
1675 case elfcpp::R_386_GNU_VTINHERIT:
1676 case elfcpp::R_386_GNU_VTENTRY:
1677 case elfcpp::R_386_GOTPC:
1678 // No symbol reference.
1681 case elfcpp::R_386_32:
1682 case elfcpp::R_386_16:
1683 case elfcpp::R_386_8:
1684 return Symbol::ABSOLUTE_REF;
1686 case elfcpp::R_386_PC32:
1687 case elfcpp::R_386_PC16:
1688 case elfcpp::R_386_PC8:
1689 case elfcpp::R_386_GOTOFF:
1690 return Symbol::RELATIVE_REF;
1692 case elfcpp::R_386_PLT32:
1693 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1695 case elfcpp::R_386_GOT32:
1696 case elfcpp::R_386_GOT32X:
1698 return Symbol::ABSOLUTE_REF;
1700 case elfcpp::R_386_TLS_GD: // Global-dynamic
1701 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1702 case elfcpp::R_386_TLS_DESC_CALL:
1703 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1704 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1705 case elfcpp::R_386_TLS_IE: // Initial-exec
1706 case elfcpp::R_386_TLS_IE_32:
1707 case elfcpp::R_386_TLS_GOTIE:
1708 case elfcpp::R_386_TLS_LE: // Local-exec
1709 case elfcpp::R_386_TLS_LE_32:
1710 return Symbol::TLS_REF;
1712 case elfcpp::R_386_COPY:
1713 case elfcpp::R_386_GLOB_DAT:
1714 case elfcpp::R_386_JUMP_SLOT:
1715 case elfcpp::R_386_RELATIVE:
1716 case elfcpp::R_386_IRELATIVE:
1717 case elfcpp::R_386_TLS_TPOFF:
1718 case elfcpp::R_386_TLS_DTPMOD32:
1719 case elfcpp::R_386_TLS_DTPOFF32:
1720 case elfcpp::R_386_TLS_TPOFF32:
1721 case elfcpp::R_386_TLS_DESC:
1722 case elfcpp::R_386_32PLT:
1723 case elfcpp::R_386_TLS_GD_32:
1724 case elfcpp::R_386_TLS_GD_PUSH:
1725 case elfcpp::R_386_TLS_GD_CALL:
1726 case elfcpp::R_386_TLS_GD_POP:
1727 case elfcpp::R_386_TLS_LDM_32:
1728 case elfcpp::R_386_TLS_LDM_PUSH:
1729 case elfcpp::R_386_TLS_LDM_CALL:
1730 case elfcpp::R_386_TLS_LDM_POP:
1731 case elfcpp::R_386_USED_BY_INTEL_200:
1733 // Not expected. We will give an error later.
1738 // Report an unsupported relocation against a local symbol.
1741 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1742 unsigned int r_type)
1744 gold_error(_("%s: unsupported reloc %u against local symbol"),
1745 object->name().c_str(), r_type);
1748 // Return whether we need to make a PLT entry for a relocation of a
1749 // given type against a STT_GNU_IFUNC symbol.
1752 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1753 Sized_relobj_file<32, false>* object,
1754 unsigned int r_type)
1756 int flags = Scan::get_reference_flags(r_type);
1757 if (flags & Symbol::TLS_REF)
1758 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1759 object->name().c_str(), r_type);
1763 // Scan a relocation for a local symbol.
1766 Target_i386::Scan::local(Symbol_table* symtab,
1768 Target_i386* target,
1769 Sized_relobj_file<32, false>* object,
1770 unsigned int data_shndx,
1771 Output_section* output_section,
1772 const elfcpp::Rel<32, false>& reloc,
1773 unsigned int r_type,
1774 const elfcpp::Sym<32, false>& lsym,
1780 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1781 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1782 && this->reloc_needs_plt_for_ifunc(object, r_type))
1784 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1785 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1790 case elfcpp::R_386_NONE:
1791 case elfcpp::R_386_GNU_VTINHERIT:
1792 case elfcpp::R_386_GNU_VTENTRY:
1795 case elfcpp::R_386_32:
1796 // If building a shared library (or a position-independent
1797 // executable), we need to create a dynamic relocation for
1798 // this location. The relocation applied at link time will
1799 // apply the link-time value, so we flag the location with
1800 // an R_386_RELATIVE relocation so the dynamic loader can
1801 // relocate it easily.
1802 if (parameters->options().output_is_position_independent())
1804 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1805 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1806 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1807 output_section, data_shndx,
1808 reloc.get_r_offset());
1812 case elfcpp::R_386_16:
1813 case elfcpp::R_386_8:
1814 // If building a shared library (or a position-independent
1815 // executable), we need to create a dynamic relocation for
1816 // this location. Because the addend needs to remain in the
1817 // data section, we need to be careful not to apply this
1818 // relocation statically.
1819 if (parameters->options().output_is_position_independent())
1821 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1822 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1823 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1824 rel_dyn->add_local(object, r_sym, r_type, output_section,
1825 data_shndx, reloc.get_r_offset());
1828 gold_assert(lsym.get_st_value() == 0);
1829 unsigned int shndx = lsym.get_st_shndx();
1831 shndx = object->adjust_sym_shndx(r_sym, shndx,
1834 object->error(_("section symbol %u has bad shndx %u"),
1837 rel_dyn->add_local_section(object, shndx,
1838 r_type, output_section,
1839 data_shndx, reloc.get_r_offset());
1844 case elfcpp::R_386_PC32:
1845 case elfcpp::R_386_PC16:
1846 case elfcpp::R_386_PC8:
1849 case elfcpp::R_386_PLT32:
1850 // Since we know this is a local symbol, we can handle this as a
1854 case elfcpp::R_386_GOTOFF:
1855 case elfcpp::R_386_GOTPC:
1856 // We need a GOT section.
1857 target->got_section(symtab, layout);
1860 case elfcpp::R_386_GOT32:
1861 case elfcpp::R_386_GOT32X:
1863 // We need GOT section.
1864 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1866 // If the relocation symbol isn't IFUNC,
1867 // and is local, then we will convert
1868 // mov foo@GOT(%reg), %reg
1870 // lea foo@GOTOFF(%reg), %reg
1871 // in Relocate::relocate.
1872 if (reloc.get_r_offset() >= 2
1873 && lsym.get_st_type() != elfcpp::STT_GNU_IFUNC)
1875 section_size_type stype;
1876 const unsigned char* view = object->section_contents(data_shndx,
1878 if (view[reloc.get_r_offset() - 2] == 0x8b)
1882 // Otherwise, the symbol requires a GOT entry.
1883 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1885 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1886 // lets function pointers compare correctly with shared
1887 // libraries. Otherwise we would need an IRELATIVE reloc.
1889 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1890 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1892 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1895 // If we are generating a shared object, we need to add a
1896 // dynamic RELATIVE relocation for this symbol's GOT entry.
1897 if (parameters->options().output_is_position_independent())
1899 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1900 unsigned int got_offset =
1901 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1902 rel_dyn->add_local_relative(object, r_sym,
1903 elfcpp::R_386_RELATIVE,
1910 // These are relocations which should only be seen by the
1911 // dynamic linker, and should never be seen here.
1912 case elfcpp::R_386_COPY:
1913 case elfcpp::R_386_GLOB_DAT:
1914 case elfcpp::R_386_JUMP_SLOT:
1915 case elfcpp::R_386_RELATIVE:
1916 case elfcpp::R_386_IRELATIVE:
1917 case elfcpp::R_386_TLS_TPOFF:
1918 case elfcpp::R_386_TLS_DTPMOD32:
1919 case elfcpp::R_386_TLS_DTPOFF32:
1920 case elfcpp::R_386_TLS_TPOFF32:
1921 case elfcpp::R_386_TLS_DESC:
1922 gold_error(_("%s: unexpected reloc %u in object file"),
1923 object->name().c_str(), r_type);
1926 // These are initial TLS relocs, which are expected when
1928 case elfcpp::R_386_TLS_GD: // Global-dynamic
1929 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1930 case elfcpp::R_386_TLS_DESC_CALL:
1931 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1932 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1933 case elfcpp::R_386_TLS_IE: // Initial-exec
1934 case elfcpp::R_386_TLS_IE_32:
1935 case elfcpp::R_386_TLS_GOTIE:
1936 case elfcpp::R_386_TLS_LE: // Local-exec
1937 case elfcpp::R_386_TLS_LE_32:
1939 bool output_is_shared = parameters->options().shared();
1940 const tls::Tls_optimization optimized_type
1941 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1944 case elfcpp::R_386_TLS_GD: // Global-dynamic
1945 if (optimized_type == tls::TLSOPT_NONE)
1947 // Create a pair of GOT entries for the module index and
1948 // dtv-relative offset.
1949 Output_data_got<32, false>* got
1950 = target->got_section(symtab, layout);
1951 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1952 unsigned int shndx = lsym.get_st_shndx();
1954 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1956 object->error(_("local symbol %u has bad shndx %u"),
1959 got->add_local_pair_with_rel(object, r_sym, shndx,
1961 target->rel_dyn_section(layout),
1962 elfcpp::R_386_TLS_DTPMOD32);
1964 else if (optimized_type != tls::TLSOPT_TO_LE)
1965 unsupported_reloc_local(object, r_type);
1968 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1969 target->define_tls_base_symbol(symtab, layout);
1970 if (optimized_type == tls::TLSOPT_NONE)
1972 // Create a double GOT entry with an R_386_TLS_DESC
1973 // reloc. The R_386_TLS_DESC reloc is resolved
1974 // lazily, so the GOT entry needs to be in an area in
1975 // .got.plt, not .got. Call got_section to make sure
1976 // the section has been created.
1977 target->got_section(symtab, layout);
1978 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1979 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1980 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1982 unsigned int got_offset = got->add_constant(0);
1983 // The local symbol value is stored in the second
1985 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1986 // That set the GOT offset of the local symbol to
1987 // point to the second entry, but we want it to
1988 // point to the first.
1989 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1991 Reloc_section* rt = target->rel_tls_desc_section(layout);
1992 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1995 else if (optimized_type != tls::TLSOPT_TO_LE)
1996 unsupported_reloc_local(object, r_type);
1999 case elfcpp::R_386_TLS_DESC_CALL:
2002 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2003 if (optimized_type == tls::TLSOPT_NONE)
2005 // Create a GOT entry for the module index.
2006 target->got_mod_index_entry(symtab, layout, object);
2008 else if (optimized_type != tls::TLSOPT_TO_LE)
2009 unsupported_reloc_local(object, r_type);
2012 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2015 case elfcpp::R_386_TLS_IE: // Initial-exec
2016 case elfcpp::R_386_TLS_IE_32:
2017 case elfcpp::R_386_TLS_GOTIE:
2018 layout->set_has_static_tls();
2019 if (optimized_type == tls::TLSOPT_NONE)
2021 // For the R_386_TLS_IE relocation, we need to create a
2022 // dynamic relocation when building a shared library.
2023 if (r_type == elfcpp::R_386_TLS_IE
2024 && parameters->options().shared())
2026 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2028 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2029 rel_dyn->add_local_relative(object, r_sym,
2030 elfcpp::R_386_RELATIVE,
2031 output_section, data_shndx,
2032 reloc.get_r_offset());
2034 // Create a GOT entry for the tp-relative offset.
2035 Output_data_got<32, false>* got
2036 = target->got_section(symtab, layout);
2037 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2038 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2039 ? elfcpp::R_386_TLS_TPOFF32
2040 : elfcpp::R_386_TLS_TPOFF);
2041 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2042 ? GOT_TYPE_TLS_OFFSET
2043 : GOT_TYPE_TLS_NOFFSET);
2044 got->add_local_with_rel(object, r_sym, got_type,
2045 target->rel_dyn_section(layout),
2048 else if (optimized_type != tls::TLSOPT_TO_LE)
2049 unsupported_reloc_local(object, r_type);
2052 case elfcpp::R_386_TLS_LE: // Local-exec
2053 case elfcpp::R_386_TLS_LE_32:
2054 layout->set_has_static_tls();
2055 if (output_is_shared)
2057 // We need to create a dynamic relocation.
2058 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2059 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2060 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2061 ? elfcpp::R_386_TLS_TPOFF32
2062 : elfcpp::R_386_TLS_TPOFF);
2063 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2064 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
2065 data_shndx, reloc.get_r_offset());
2075 case elfcpp::R_386_32PLT:
2076 case elfcpp::R_386_TLS_GD_32:
2077 case elfcpp::R_386_TLS_GD_PUSH:
2078 case elfcpp::R_386_TLS_GD_CALL:
2079 case elfcpp::R_386_TLS_GD_POP:
2080 case elfcpp::R_386_TLS_LDM_32:
2081 case elfcpp::R_386_TLS_LDM_PUSH:
2082 case elfcpp::R_386_TLS_LDM_CALL:
2083 case elfcpp::R_386_TLS_LDM_POP:
2084 case elfcpp::R_386_USED_BY_INTEL_200:
2086 unsupported_reloc_local(object, r_type);
2091 // Report an unsupported relocation against a global symbol.
2094 Target_i386::Scan::unsupported_reloc_global(
2095 Sized_relobj_file<32, false>* object,
2096 unsigned int r_type,
2099 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2100 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2104 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
2108 case elfcpp::R_386_32:
2109 case elfcpp::R_386_16:
2110 case elfcpp::R_386_8:
2111 case elfcpp::R_386_GOTOFF:
2112 case elfcpp::R_386_GOT32:
2113 case elfcpp::R_386_GOT32X:
2124 Target_i386::Scan::local_reloc_may_be_function_pointer(
2128 Sized_relobj_file<32, false>* ,
2131 const elfcpp::Rel<32, false>& ,
2132 unsigned int r_type,
2133 const elfcpp::Sym<32, false>&)
2135 return possible_function_pointer_reloc(r_type);
2139 Target_i386::Scan::global_reloc_may_be_function_pointer(
2143 Sized_relobj_file<32, false>* ,
2146 const elfcpp::Rel<32, false>& ,
2147 unsigned int r_type,
2150 return possible_function_pointer_reloc(r_type);
2153 // Scan a relocation for a global symbol.
2156 Target_i386::Scan::global(Symbol_table* symtab,
2158 Target_i386* target,
2159 Sized_relobj_file<32, false>* object,
2160 unsigned int data_shndx,
2161 Output_section* output_section,
2162 const elfcpp::Rel<32, false>& reloc,
2163 unsigned int r_type,
2166 // A STT_GNU_IFUNC symbol may require a PLT entry.
2167 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2168 && this->reloc_needs_plt_for_ifunc(object, r_type))
2169 target->make_plt_entry(symtab, layout, gsym);
2173 case elfcpp::R_386_NONE:
2174 case elfcpp::R_386_GNU_VTINHERIT:
2175 case elfcpp::R_386_GNU_VTENTRY:
2178 case elfcpp::R_386_32:
2179 case elfcpp::R_386_16:
2180 case elfcpp::R_386_8:
2182 // Make a PLT entry if necessary.
2183 if (gsym->needs_plt_entry())
2185 target->make_plt_entry(symtab, layout, gsym);
2186 // Since this is not a PC-relative relocation, we may be
2187 // taking the address of a function. In that case we need to
2188 // set the entry in the dynamic symbol table to the address of
2190 if (gsym->is_from_dynobj() && !parameters->options().shared())
2191 gsym->set_needs_dynsym_value();
2193 // Make a dynamic relocation if necessary.
2194 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2196 if (!parameters->options().output_is_position_independent()
2197 && gsym->may_need_copy_reloc())
2199 target->copy_reloc(symtab, layout, object,
2200 data_shndx, output_section, gsym, reloc);
2202 else if (r_type == elfcpp::R_386_32
2203 && gsym->type() == elfcpp::STT_GNU_IFUNC
2204 && gsym->can_use_relative_reloc(false)
2205 && !gsym->is_from_dynobj()
2206 && !gsym->is_undefined()
2207 && !gsym->is_preemptible())
2209 // Use an IRELATIVE reloc for a locally defined
2210 // STT_GNU_IFUNC symbol. This makes a function
2211 // address in a PIE executable match the address in a
2212 // shared library that it links against.
2213 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
2214 rel_dyn->add_symbolless_global_addend(gsym,
2215 elfcpp::R_386_IRELATIVE,
2218 reloc.get_r_offset());
2220 else if (r_type == elfcpp::R_386_32
2221 && gsym->can_use_relative_reloc(false))
2223 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2224 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2225 output_section, object,
2226 data_shndx, reloc.get_r_offset());
2230 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2231 rel_dyn->add_global(gsym, r_type, output_section, object,
2232 data_shndx, reloc.get_r_offset());
2238 case elfcpp::R_386_PC32:
2239 case elfcpp::R_386_PC16:
2240 case elfcpp::R_386_PC8:
2242 // Make a PLT entry if necessary.
2243 if (gsym->needs_plt_entry())
2245 // These relocations are used for function calls only in
2246 // non-PIC code. For a 32-bit relocation in a shared library,
2247 // we'll need a text relocation anyway, so we can skip the
2248 // PLT entry and let the dynamic linker bind the call directly
2249 // to the target. For smaller relocations, we should use a
2250 // PLT entry to ensure that the call can reach.
2251 if (!parameters->options().shared()
2252 || r_type != elfcpp::R_386_PC32)
2253 target->make_plt_entry(symtab, layout, gsym);
2255 // Make a dynamic relocation if necessary.
2256 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2258 if (parameters->options().output_is_executable()
2259 && gsym->may_need_copy_reloc())
2261 target->copy_reloc(symtab, layout, object,
2262 data_shndx, output_section, gsym, reloc);
2266 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2267 rel_dyn->add_global(gsym, r_type, output_section, object,
2268 data_shndx, reloc.get_r_offset());
2274 case elfcpp::R_386_GOT32:
2275 case elfcpp::R_386_GOT32X:
2277 // The symbol requires a GOT section.
2278 Output_data_got<32, false>* got = target->got_section(symtab, layout);
2280 // If we convert this from
2281 // mov foo@GOT(%reg), %reg
2283 // lea foo@GOTOFF(%reg), %reg
2284 // in Relocate::relocate, then there is nothing to do here.
2285 if (reloc.get_r_offset() >= 2
2286 && Target_i386::can_convert_mov_to_lea(gsym))
2288 section_size_type stype;
2289 const unsigned char* view = object->section_contents(data_shndx,
2291 if (view[reloc.get_r_offset() - 2] == 0x8b)
2295 if (gsym->final_value_is_known())
2297 // For a STT_GNU_IFUNC symbol we want the PLT address.
2298 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2299 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2301 got->add_global(gsym, GOT_TYPE_STANDARD);
2305 // If this symbol is not fully resolved, we need to add a
2306 // GOT entry with a dynamic relocation.
2307 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2309 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2311 // 1) The symbol may be defined in some other module.
2313 // 2) We are building a shared library and this is a
2314 // protected symbol; using GLOB_DAT means that the dynamic
2315 // linker can use the address of the PLT in the main
2316 // executable when appropriate so that function address
2317 // comparisons work.
2319 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2320 // code, again so that function address comparisons work.
2321 if (gsym->is_from_dynobj()
2322 || gsym->is_undefined()
2323 || gsym->is_preemptible()
2324 || (gsym->visibility() == elfcpp::STV_PROTECTED
2325 && parameters->options().shared())
2326 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2327 && parameters->options().output_is_position_independent()))
2328 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2329 rel_dyn, elfcpp::R_386_GLOB_DAT);
2332 // For a STT_GNU_IFUNC symbol we want to write the PLT
2333 // offset into the GOT, so that function pointer
2334 // comparisons work correctly.
2336 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2337 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2340 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2341 // Tell the dynamic linker to use the PLT address
2342 // when resolving relocations.
2343 if (gsym->is_from_dynobj()
2344 && !parameters->options().shared())
2345 gsym->set_needs_dynsym_value();
2349 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2350 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2358 case elfcpp::R_386_PLT32:
2359 // If the symbol is fully resolved, this is just a PC32 reloc.
2360 // Otherwise we need a PLT entry.
2361 if (gsym->final_value_is_known())
2363 // If building a shared library, we can also skip the PLT entry
2364 // if the symbol is defined in the output file and is protected
2366 if (gsym->is_defined()
2367 && !gsym->is_from_dynobj()
2368 && !gsym->is_preemptible())
2370 target->make_plt_entry(symtab, layout, gsym);
2373 case elfcpp::R_386_GOTOFF:
2374 case elfcpp::R_386_GOTPC:
2375 // We need a GOT section.
2376 target->got_section(symtab, layout);
2379 // These are relocations which should only be seen by the
2380 // dynamic linker, and should never be seen here.
2381 case elfcpp::R_386_COPY:
2382 case elfcpp::R_386_GLOB_DAT:
2383 case elfcpp::R_386_JUMP_SLOT:
2384 case elfcpp::R_386_RELATIVE:
2385 case elfcpp::R_386_IRELATIVE:
2386 case elfcpp::R_386_TLS_TPOFF:
2387 case elfcpp::R_386_TLS_DTPMOD32:
2388 case elfcpp::R_386_TLS_DTPOFF32:
2389 case elfcpp::R_386_TLS_TPOFF32:
2390 case elfcpp::R_386_TLS_DESC:
2391 gold_error(_("%s: unexpected reloc %u in object file"),
2392 object->name().c_str(), r_type);
2395 // These are initial tls relocs, which are expected when
2397 case elfcpp::R_386_TLS_GD: // Global-dynamic
2398 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2399 case elfcpp::R_386_TLS_DESC_CALL:
2400 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2401 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2402 case elfcpp::R_386_TLS_IE: // Initial-exec
2403 case elfcpp::R_386_TLS_IE_32:
2404 case elfcpp::R_386_TLS_GOTIE:
2405 case elfcpp::R_386_TLS_LE: // Local-exec
2406 case elfcpp::R_386_TLS_LE_32:
2408 const bool is_final = gsym->final_value_is_known();
2409 const tls::Tls_optimization optimized_type
2410 = Target_i386::optimize_tls_reloc(is_final, r_type);
2413 case elfcpp::R_386_TLS_GD: // Global-dynamic
2414 if (optimized_type == tls::TLSOPT_NONE)
2416 // Create a pair of GOT entries for the module index and
2417 // dtv-relative offset.
2418 Output_data_got<32, false>* got
2419 = target->got_section(symtab, layout);
2420 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2421 target->rel_dyn_section(layout),
2422 elfcpp::R_386_TLS_DTPMOD32,
2423 elfcpp::R_386_TLS_DTPOFF32);
2425 else if (optimized_type == tls::TLSOPT_TO_IE)
2427 // Create a GOT entry for the tp-relative offset.
2428 Output_data_got<32, false>* got
2429 = target->got_section(symtab, layout);
2430 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2431 target->rel_dyn_section(layout),
2432 elfcpp::R_386_TLS_TPOFF);
2434 else if (optimized_type != tls::TLSOPT_TO_LE)
2435 unsupported_reloc_global(object, r_type, gsym);
2438 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
2439 target->define_tls_base_symbol(symtab, layout);
2440 if (optimized_type == tls::TLSOPT_NONE)
2442 // Create a double GOT entry with an R_386_TLS_DESC
2443 // reloc. The R_386_TLS_DESC reloc is resolved
2444 // lazily, so the GOT entry needs to be in an area in
2445 // .got.plt, not .got. Call got_section to make sure
2446 // the section has been created.
2447 target->got_section(symtab, layout);
2448 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2449 Reloc_section* rt = target->rel_tls_desc_section(layout);
2450 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2451 elfcpp::R_386_TLS_DESC, 0);
2453 else if (optimized_type == tls::TLSOPT_TO_IE)
2455 // Create a GOT entry for the tp-relative offset.
2456 Output_data_got<32, false>* got
2457 = target->got_section(symtab, layout);
2458 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2459 target->rel_dyn_section(layout),
2460 elfcpp::R_386_TLS_TPOFF);
2462 else if (optimized_type != tls::TLSOPT_TO_LE)
2463 unsupported_reloc_global(object, r_type, gsym);
2466 case elfcpp::R_386_TLS_DESC_CALL:
2469 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2470 if (optimized_type == tls::TLSOPT_NONE)
2472 // Create a GOT entry for the module index.
2473 target->got_mod_index_entry(symtab, layout, object);
2475 else if (optimized_type != tls::TLSOPT_TO_LE)
2476 unsupported_reloc_global(object, r_type, gsym);
2479 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2482 case elfcpp::R_386_TLS_IE: // Initial-exec
2483 case elfcpp::R_386_TLS_IE_32:
2484 case elfcpp::R_386_TLS_GOTIE:
2485 layout->set_has_static_tls();
2486 if (optimized_type == tls::TLSOPT_NONE)
2488 // For the R_386_TLS_IE relocation, we need to create a
2489 // dynamic relocation when building a shared library.
2490 if (r_type == elfcpp::R_386_TLS_IE
2491 && parameters->options().shared())
2493 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2494 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2495 output_section, object,
2497 reloc.get_r_offset());
2499 // Create a GOT entry for the tp-relative offset.
2500 Output_data_got<32, false>* got
2501 = target->got_section(symtab, layout);
2502 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2503 ? elfcpp::R_386_TLS_TPOFF32
2504 : elfcpp::R_386_TLS_TPOFF);
2505 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2506 ? GOT_TYPE_TLS_OFFSET
2507 : GOT_TYPE_TLS_NOFFSET);
2508 got->add_global_with_rel(gsym, got_type,
2509 target->rel_dyn_section(layout),
2512 else if (optimized_type != tls::TLSOPT_TO_LE)
2513 unsupported_reloc_global(object, r_type, gsym);
2516 case elfcpp::R_386_TLS_LE: // Local-exec
2517 case elfcpp::R_386_TLS_LE_32:
2518 layout->set_has_static_tls();
2519 if (parameters->options().shared())
2521 // We need to create a dynamic relocation.
2522 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2523 ? elfcpp::R_386_TLS_TPOFF32
2524 : elfcpp::R_386_TLS_TPOFF);
2525 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2526 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2527 data_shndx, reloc.get_r_offset());
2537 case elfcpp::R_386_32PLT:
2538 case elfcpp::R_386_TLS_GD_32:
2539 case elfcpp::R_386_TLS_GD_PUSH:
2540 case elfcpp::R_386_TLS_GD_CALL:
2541 case elfcpp::R_386_TLS_GD_POP:
2542 case elfcpp::R_386_TLS_LDM_32:
2543 case elfcpp::R_386_TLS_LDM_PUSH:
2544 case elfcpp::R_386_TLS_LDM_CALL:
2545 case elfcpp::R_386_TLS_LDM_POP:
2546 case elfcpp::R_386_USED_BY_INTEL_200:
2548 unsupported_reloc_global(object, r_type, gsym);
2553 // Process relocations for gc.
2556 Target_i386::gc_process_relocs(Symbol_table* symtab,
2558 Sized_relobj_file<32, false>* object,
2559 unsigned int data_shndx,
2561 const unsigned char* prelocs,
2563 Output_section* output_section,
2564 bool needs_special_offset_handling,
2565 size_t local_symbol_count,
2566 const unsigned char* plocal_symbols)
2568 gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2570 Target_i386::Relocatable_size_for_reloc>(
2579 needs_special_offset_handling,
2584 // Scan relocations for a section.
2587 Target_i386::scan_relocs(Symbol_table* symtab,
2589 Sized_relobj_file<32, false>* object,
2590 unsigned int data_shndx,
2591 unsigned int sh_type,
2592 const unsigned char* prelocs,
2594 Output_section* output_section,
2595 bool needs_special_offset_handling,
2596 size_t local_symbol_count,
2597 const unsigned char* plocal_symbols)
2599 if (sh_type == elfcpp::SHT_RELA)
2601 gold_error(_("%s: unsupported RELA reloc section"),
2602 object->name().c_str());
2606 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2616 needs_special_offset_handling,
2621 // Finalize the sections.
2624 Target_i386::do_finalize_sections(
2626 const Input_objects*,
2627 Symbol_table* symtab)
2629 const Reloc_section* rel_plt = (this->plt_ == NULL
2631 : this->plt_->rel_plt());
2632 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2633 this->rel_dyn_, true, false);
2635 // Emit any relocs we saved in an attempt to avoid generating COPY
2637 if (this->copy_relocs_.any_saved_relocs())
2638 this->copy_relocs_.emit(this->rel_dyn_section(layout));
2640 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2641 // the .got.plt section.
2642 Symbol* sym = this->global_offset_table_;
2645 uint32_t data_size = this->got_plt_->current_data_size();
2646 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2649 if (parameters->doing_static_link()
2650 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2652 // If linking statically, make sure that the __rel_iplt symbols
2653 // were defined if necessary, even if we didn't create a PLT.
2654 static const Define_symbol_in_segment syms[] =
2657 "__rel_iplt_start", // name
2658 elfcpp::PT_LOAD, // segment_type
2659 elfcpp::PF_W, // segment_flags_set
2660 elfcpp::PF(0), // segment_flags_clear
2663 elfcpp::STT_NOTYPE, // type
2664 elfcpp::STB_GLOBAL, // binding
2665 elfcpp::STV_HIDDEN, // visibility
2667 Symbol::SEGMENT_START, // offset_from_base
2671 "__rel_iplt_end", // name
2672 elfcpp::PT_LOAD, // segment_type
2673 elfcpp::PF_W, // segment_flags_set
2674 elfcpp::PF(0), // segment_flags_clear
2677 elfcpp::STT_NOTYPE, // type
2678 elfcpp::STB_GLOBAL, // binding
2679 elfcpp::STV_HIDDEN, // visibility
2681 Symbol::SEGMENT_START, // offset_from_base
2686 symtab->define_symbols(layout, 2, syms,
2687 layout->script_options()->saw_sections_clause());
2691 // Return whether a direct absolute static relocation needs to be applied.
2692 // In cases where Scan::local() or Scan::global() has created
2693 // a dynamic relocation other than R_386_RELATIVE, the addend
2694 // of the relocation is carried in the data, and we must not
2695 // apply the static relocation.
2698 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2699 unsigned int r_type,
2701 Output_section* output_section)
2703 // If the output section is not allocated, then we didn't call
2704 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2706 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2709 int ref_flags = Scan::get_reference_flags(r_type);
2711 // For local symbols, we will have created a non-RELATIVE dynamic
2712 // relocation only if (a) the output is position independent,
2713 // (b) the relocation is absolute (not pc- or segment-relative), and
2714 // (c) the relocation is not 32 bits wide.
2716 return !(parameters->options().output_is_position_independent()
2717 && (ref_flags & Symbol::ABSOLUTE_REF)
2720 // For global symbols, we use the same helper routines used in the
2721 // scan pass. If we did not create a dynamic relocation, or if we
2722 // created a RELATIVE dynamic relocation, we should apply the static
2724 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2725 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2726 && gsym->can_use_relative_reloc(ref_flags
2727 & Symbol::FUNCTION_CALL);
2728 return !has_dyn || is_rel;
2731 // Perform a relocation.
2734 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2735 Target_i386* target,
2736 Output_section* output_section,
2738 const elfcpp::Rel<32, false>& rel,
2739 unsigned int r_type,
2740 const Sized_symbol<32>* gsym,
2741 const Symbol_value<32>* psymval,
2742 unsigned char* view,
2743 elfcpp::Elf_types<32>::Elf_Addr address,
2744 section_size_type view_size)
2746 if (this->skip_call_tls_get_addr_)
2748 if ((r_type != elfcpp::R_386_PLT32
2749 && r_type != elfcpp::R_386_PC32)
2751 || strcmp(gsym->name(), "___tls_get_addr") != 0)
2752 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2753 _("missing expected TLS relocation"));
2756 this->skip_call_tls_get_addr_ = false;
2764 const Sized_relobj_file<32, false>* object = relinfo->object;
2766 // Pick the value to use for symbols defined in shared objects.
2767 Symbol_value<32> symval;
2769 && gsym->type() == elfcpp::STT_GNU_IFUNC
2770 && r_type == elfcpp::R_386_32
2771 && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2772 && gsym->can_use_relative_reloc(false)
2773 && !gsym->is_from_dynobj()
2774 && !gsym->is_undefined()
2775 && !gsym->is_preemptible())
2777 // In this case we are generating a R_386_IRELATIVE reloc. We
2778 // want to use the real value of the symbol, not the PLT offset.
2780 else if (gsym != NULL
2781 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2783 symval.set_output_value(target->plt_address_for_global(gsym));
2786 else if (gsym == NULL && psymval->is_ifunc_symbol())
2788 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2789 if (object->local_has_plt_offset(r_sym))
2791 symval.set_output_value(target->plt_address_for_local(object, r_sym));
2800 case elfcpp::R_386_NONE:
2801 case elfcpp::R_386_GNU_VTINHERIT:
2802 case elfcpp::R_386_GNU_VTENTRY:
2805 case elfcpp::R_386_32:
2806 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2807 Relocate_functions<32, false>::rel32(view, object, psymval);
2810 case elfcpp::R_386_PC32:
2811 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2812 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2815 case elfcpp::R_386_16:
2816 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2817 Relocate_functions<32, false>::rel16(view, object, psymval);
2820 case elfcpp::R_386_PC16:
2821 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2822 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2825 case elfcpp::R_386_8:
2826 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2827 Relocate_functions<32, false>::rel8(view, object, psymval);
2830 case elfcpp::R_386_PC8:
2831 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2832 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2835 case elfcpp::R_386_PLT32:
2836 gold_assert(gsym == NULL
2837 || gsym->has_plt_offset()
2838 || gsym->final_value_is_known()
2839 || (gsym->is_defined()
2840 && !gsym->is_from_dynobj()
2841 && !gsym->is_preemptible()));
2842 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2845 case elfcpp::R_386_GOT32:
2846 case elfcpp::R_386_GOT32X:
2847 baseless = (view[-1] & 0xc7) == 0x5;
2848 // R_386_GOT32 and R_386_GOT32X don't work without base register
2849 // when generating a position-independent output file.
2851 && parameters->options().output_is_position_independent())
2854 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2855 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2856 r_type, gsym->demangled_name().c_str());
2858 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2859 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2864 // mov foo@GOT(%reg), %reg
2866 // lea foo@GOTOFF(%reg), %reg
2868 if (rel.get_r_offset() >= 2
2870 && ((gsym == NULL && !psymval->is_ifunc_symbol())
2872 && Target_i386::can_convert_mov_to_lea(gsym))))
2875 elfcpp::Elf_types<32>::Elf_Addr value;
2876 value = psymval->value(object, 0);
2877 // Don't subtract the .got.plt section address for baseless
2880 value -= target->got_plt_section()->address();
2881 Relocate_functions<32, false>::rel32(view, value);
2885 // The GOT pointer points to the end of the GOT section.
2886 // We need to subtract the size of the GOT section to get
2887 // the actual offset to use in the relocation.
2888 unsigned int got_offset = 0;
2891 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2892 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2893 - target->got_size());
2897 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2898 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2899 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2900 - target->got_size());
2902 // Add the .got.plt section address for baseless addressing.
2904 got_offset += target->got_plt_section()->address();
2905 Relocate_functions<32, false>::rel32(view, got_offset);
2909 case elfcpp::R_386_GOTOFF:
2911 elfcpp::Elf_types<32>::Elf_Addr value;
2912 value = (psymval->value(object, 0)
2913 - target->got_plt_section()->address());
2914 Relocate_functions<32, false>::rel32(view, value);
2918 case elfcpp::R_386_GOTPC:
2920 elfcpp::Elf_types<32>::Elf_Addr value;
2921 value = target->got_plt_section()->address();
2922 Relocate_functions<32, false>::pcrel32(view, value, address);
2926 case elfcpp::R_386_COPY:
2927 case elfcpp::R_386_GLOB_DAT:
2928 case elfcpp::R_386_JUMP_SLOT:
2929 case elfcpp::R_386_RELATIVE:
2930 case elfcpp::R_386_IRELATIVE:
2931 // These are outstanding tls relocs, which are unexpected when
2933 case elfcpp::R_386_TLS_TPOFF:
2934 case elfcpp::R_386_TLS_DTPMOD32:
2935 case elfcpp::R_386_TLS_DTPOFF32:
2936 case elfcpp::R_386_TLS_TPOFF32:
2937 case elfcpp::R_386_TLS_DESC:
2938 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2939 _("unexpected reloc %u in object file"),
2943 // These are initial tls relocs, which are expected when
2945 case elfcpp::R_386_TLS_GD: // Global-dynamic
2946 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2947 case elfcpp::R_386_TLS_DESC_CALL:
2948 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2949 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2950 case elfcpp::R_386_TLS_IE: // Initial-exec
2951 case elfcpp::R_386_TLS_IE_32:
2952 case elfcpp::R_386_TLS_GOTIE:
2953 case elfcpp::R_386_TLS_LE: // Local-exec
2954 case elfcpp::R_386_TLS_LE_32:
2955 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2956 view, address, view_size);
2959 case elfcpp::R_386_32PLT:
2960 case elfcpp::R_386_TLS_GD_32:
2961 case elfcpp::R_386_TLS_GD_PUSH:
2962 case elfcpp::R_386_TLS_GD_CALL:
2963 case elfcpp::R_386_TLS_GD_POP:
2964 case elfcpp::R_386_TLS_LDM_32:
2965 case elfcpp::R_386_TLS_LDM_PUSH:
2966 case elfcpp::R_386_TLS_LDM_CALL:
2967 case elfcpp::R_386_TLS_LDM_POP:
2968 case elfcpp::R_386_USED_BY_INTEL_200:
2970 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2971 _("unsupported reloc %u"),
2979 // Perform a TLS relocation.
2982 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2983 Target_i386* target,
2985 const elfcpp::Rel<32, false>& rel,
2986 unsigned int r_type,
2987 const Sized_symbol<32>* gsym,
2988 const Symbol_value<32>* psymval,
2989 unsigned char* view,
2990 elfcpp::Elf_types<32>::Elf_Addr,
2991 section_size_type view_size)
2993 Output_segment* tls_segment = relinfo->layout->tls_segment();
2995 const Sized_relobj_file<32, false>* object = relinfo->object;
2997 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2999 const bool is_final = (gsym == NULL
3000 ? !parameters->options().shared()
3001 : gsym->final_value_is_known());
3002 const tls::Tls_optimization optimized_type
3003 = Target_i386::optimize_tls_reloc(is_final, r_type);
3006 case elfcpp::R_386_TLS_GD: // Global-dynamic
3007 if (optimized_type == tls::TLSOPT_TO_LE)
3009 if (tls_segment == NULL)
3011 gold_assert(parameters->errors()->error_count() > 0
3012 || issue_undefined_symbol_error(gsym));
3015 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3016 rel, r_type, value, view,
3022 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3023 ? GOT_TYPE_TLS_NOFFSET
3024 : GOT_TYPE_TLS_PAIR);
3025 unsigned int got_offset;
3028 gold_assert(gsym->has_got_offset(got_type));
3029 got_offset = gsym->got_offset(got_type) - target->got_size();
3033 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3034 gold_assert(object->local_has_got_offset(r_sym, got_type));
3035 got_offset = (object->local_got_offset(r_sym, got_type)
3036 - target->got_size());
3038 if (optimized_type == tls::TLSOPT_TO_IE)
3040 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
3041 got_offset, view, view_size);
3044 else if (optimized_type == tls::TLSOPT_NONE)
3046 // Relocate the field with the offset of the pair of GOT
3048 Relocate_functions<32, false>::rel32(view, got_offset);
3052 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3053 _("unsupported reloc %u"),
3057 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3058 case elfcpp::R_386_TLS_DESC_CALL:
3059 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3060 if (optimized_type == tls::TLSOPT_TO_LE)
3062 if (tls_segment == NULL)
3064 gold_assert(parameters->errors()->error_count() > 0
3065 || issue_undefined_symbol_error(gsym));
3068 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3069 rel, r_type, value, view,
3075 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3076 ? GOT_TYPE_TLS_NOFFSET
3077 : GOT_TYPE_TLS_DESC);
3078 unsigned int got_offset = 0;
3079 if (r_type == elfcpp::R_386_TLS_GOTDESC
3080 && optimized_type == tls::TLSOPT_NONE)
3082 // We created GOT entries in the .got.tlsdesc portion of
3083 // the .got.plt section, but the offset stored in the
3084 // symbol is the offset within .got.tlsdesc.
3085 got_offset = (target->got_size()
3086 + target->got_plt_section()->data_size());
3090 gold_assert(gsym->has_got_offset(got_type));
3091 got_offset += gsym->got_offset(got_type) - target->got_size();
3095 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3096 gold_assert(object->local_has_got_offset(r_sym, got_type));
3097 got_offset += (object->local_got_offset(r_sym, got_type)
3098 - target->got_size());
3100 if (optimized_type == tls::TLSOPT_TO_IE)
3102 if (tls_segment == NULL)
3104 gold_assert(parameters->errors()->error_count() > 0
3105 || issue_undefined_symbol_error(gsym));
3108 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
3109 got_offset, view, view_size);
3112 else if (optimized_type == tls::TLSOPT_NONE)
3114 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3116 // Relocate the field with the offset of the pair of GOT
3118 Relocate_functions<32, false>::rel32(view, got_offset);
3123 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3124 _("unsupported reloc %u"),
3128 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3129 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
3131 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3132 _("both SUN and GNU model "
3133 "TLS relocations"));
3136 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3137 if (optimized_type == tls::TLSOPT_TO_LE)
3139 if (tls_segment == NULL)
3141 gold_assert(parameters->errors()->error_count() > 0
3142 || issue_undefined_symbol_error(gsym));
3145 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
3146 value, view, view_size);
3149 else if (optimized_type == tls::TLSOPT_NONE)
3151 // Relocate the field with the offset of the GOT entry for
3152 // the module index.
3153 unsigned int got_offset;
3154 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3155 - target->got_size());
3156 Relocate_functions<32, false>::rel32(view, got_offset);
3159 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3160 _("unsupported reloc %u"),
3164 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3165 if (optimized_type == tls::TLSOPT_TO_LE)
3167 // This reloc can appear in debugging sections, in which
3168 // case we must not convert to local-exec. We decide what
3169 // to do based on whether the section is marked as
3170 // containing executable code. That is what the GNU linker
3172 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
3173 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
3175 if (tls_segment == NULL)
3177 gold_assert(parameters->errors()->error_count() > 0
3178 || issue_undefined_symbol_error(gsym));
3181 value -= tls_segment->memsz();
3184 Relocate_functions<32, false>::rel32(view, value);
3187 case elfcpp::R_386_TLS_IE: // Initial-exec
3188 case elfcpp::R_386_TLS_GOTIE:
3189 case elfcpp::R_386_TLS_IE_32:
3190 if (optimized_type == tls::TLSOPT_TO_LE)
3192 if (tls_segment == NULL)
3194 gold_assert(parameters->errors()->error_count() > 0
3195 || issue_undefined_symbol_error(gsym));
3198 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3199 rel, r_type, value, view,
3203 else if (optimized_type == tls::TLSOPT_NONE)
3205 // Relocate the field with the offset of the GOT entry for
3206 // the tp-relative offset of the symbol.
3207 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
3208 ? GOT_TYPE_TLS_OFFSET
3209 : GOT_TYPE_TLS_NOFFSET);
3210 unsigned int got_offset;
3213 gold_assert(gsym->has_got_offset(got_type));
3214 got_offset = gsym->got_offset(got_type);
3218 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3219 gold_assert(object->local_has_got_offset(r_sym, got_type));
3220 got_offset = object->local_got_offset(r_sym, got_type);
3222 // For the R_386_TLS_IE relocation, we need to apply the
3223 // absolute address of the GOT entry.
3224 if (r_type == elfcpp::R_386_TLS_IE)
3225 got_offset += target->got_plt_section()->address();
3226 // All GOT offsets are relative to the end of the GOT.
3227 got_offset -= target->got_size();
3228 Relocate_functions<32, false>::rel32(view, got_offset);
3231 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3232 _("unsupported reloc %u"),
3236 case elfcpp::R_386_TLS_LE: // Local-exec
3237 // If we're creating a shared library, a dynamic relocation will
3238 // have been created for this location, so do not apply it now.
3239 if (!parameters->options().shared())
3241 if (tls_segment == NULL)
3243 gold_assert(parameters->errors()->error_count() > 0
3244 || issue_undefined_symbol_error(gsym));
3247 value -= tls_segment->memsz();
3248 Relocate_functions<32, false>::rel32(view, value);
3252 case elfcpp::R_386_TLS_LE_32:
3253 // If we're creating a shared library, a dynamic relocation will
3254 // have been created for this location, so do not apply it now.
3255 if (!parameters->options().shared())
3257 if (tls_segment == NULL)
3259 gold_assert(parameters->errors()->error_count() > 0
3260 || issue_undefined_symbol_error(gsym));
3263 value = tls_segment->memsz() - value;
3264 Relocate_functions<32, false>::rel32(view, value);
3270 // Do a relocation in which we convert a TLS General-Dynamic to a
3274 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
3276 Output_segment* tls_segment,
3277 const elfcpp::Rel<32, false>& rel,
3279 elfcpp::Elf_types<32>::Elf_Addr value,
3280 unsigned char* view,
3281 section_size_type view_size)
3283 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3284 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3285 // leal foo(%reg),%eax; call ___tls_get_addr
3286 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3288 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3289 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3291 unsigned char op1 = view[-1];
3292 unsigned char op2 = view[-2];
3294 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3295 op2 == 0x8d || op2 == 0x04);
3296 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3302 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3303 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3304 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3305 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3306 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3310 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3311 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3312 if (rel.get_r_offset() + 9 < view_size
3315 // There is a trailing nop. Use the size byte subl.
3316 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3321 // Use the five byte subl.
3322 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3326 value = tls_segment->memsz() - value;
3327 Relocate_functions<32, false>::rel32(view + roff, value);
3329 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3331 this->skip_call_tls_get_addr_ = true;
3334 // Do a relocation in which we convert a TLS General-Dynamic to an
3338 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3341 const elfcpp::Rel<32, false>& rel,
3343 elfcpp::Elf_types<32>::Elf_Addr value,
3344 unsigned char* view,
3345 section_size_type view_size)
3347 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3348 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3349 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3350 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3352 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3353 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3355 unsigned char op1 = view[-1];
3356 unsigned char op2 = view[-2];
3358 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3359 op2 == 0x8d || op2 == 0x04);
3360 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3366 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3367 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3368 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3369 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3374 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
3375 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3376 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3377 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[9] == 0x90);
3381 memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3382 Relocate_functions<32, false>::rel32(view + roff, value);
3384 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3386 this->skip_call_tls_get_addr_ = true;
3389 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3390 // General-Dynamic to a Local-Exec.
3393 Target_i386::Relocate::tls_desc_gd_to_le(
3394 const Relocate_info<32, false>* relinfo,
3396 Output_segment* tls_segment,
3397 const elfcpp::Rel<32, false>& rel,
3398 unsigned int r_type,
3399 elfcpp::Elf_types<32>::Elf_Addr value,
3400 unsigned char* view,
3401 section_size_type view_size)
3403 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3405 // leal foo@TLSDESC(%ebx), %eax
3406 // ==> leal foo@NTPOFF, %eax
3407 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3408 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3409 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3410 view[-2] == 0x8d && view[-1] == 0x83);
3412 value -= tls_segment->memsz();
3413 Relocate_functions<32, false>::rel32(view, value);
3417 // call *foo@TLSCALL(%eax)
3419 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3420 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3421 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3422 view[0] == 0xff && view[1] == 0x10);
3428 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3429 // General-Dynamic to an Initial-Exec.
3432 Target_i386::Relocate::tls_desc_gd_to_ie(
3433 const Relocate_info<32, false>* relinfo,
3436 const elfcpp::Rel<32, false>& rel,
3437 unsigned int r_type,
3438 elfcpp::Elf_types<32>::Elf_Addr value,
3439 unsigned char* view,
3440 section_size_type view_size)
3442 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3444 // leal foo@TLSDESC(%ebx), %eax
3445 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3446 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3447 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3448 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3449 view[-2] == 0x8d && view[-1] == 0x83);
3451 Relocate_functions<32, false>::rel32(view, value);
3455 // call *foo@TLSCALL(%eax)
3457 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3458 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3459 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3460 view[0] == 0xff && view[1] == 0x10);
3466 // Do a relocation in which we convert a TLS Local-Dynamic to a
3470 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3473 const elfcpp::Rel<32, false>& rel,
3475 elfcpp::Elf_types<32>::Elf_Addr,
3476 unsigned char* view,
3477 section_size_type view_size)
3479 // leal foo(%reg), %eax; call ___tls_get_addr
3480 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3482 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3483 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3485 // FIXME: Does this test really always pass?
3486 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3487 view[-2] == 0x8d && view[-1] == 0x83);
3489 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3491 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3493 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3495 this->skip_call_tls_get_addr_ = true;
3498 // Do a relocation in which we convert a TLS Initial-Exec to a
3502 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3504 Output_segment* tls_segment,
3505 const elfcpp::Rel<32, false>& rel,
3506 unsigned int r_type,
3507 elfcpp::Elf_types<32>::Elf_Addr value,
3508 unsigned char* view,
3509 section_size_type view_size)
3511 // We have to actually change the instructions, which means that we
3512 // need to examine the opcodes to figure out which instruction we
3514 if (r_type == elfcpp::R_386_TLS_IE)
3516 // movl %gs:XX,%eax ==> movl $YY,%eax
3517 // movl %gs:XX,%reg ==> movl $YY,%reg
3518 // addl %gs:XX,%reg ==> addl $YY,%reg
3519 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3520 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3522 unsigned char op1 = view[-1];
3525 // movl XX,%eax ==> movl $YY,%eax
3530 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3532 unsigned char op2 = view[-2];
3535 // movl XX,%reg ==> movl $YY,%reg
3536 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3537 (op1 & 0xc7) == 0x05);
3539 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3541 else if (op2 == 0x03)
3543 // addl XX,%reg ==> addl $YY,%reg
3544 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3545 (op1 & 0xc7) == 0x05);
3547 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3550 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3555 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3556 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3557 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3558 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3559 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3561 unsigned char op1 = view[-1];
3562 unsigned char op2 = view[-2];
3563 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3564 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3567 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3569 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3571 else if (op2 == 0x2b)
3573 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3575 view[-1] = 0xe8 | ((op1 >> 3) & 7);
3577 else if (op2 == 0x03)
3579 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3581 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3584 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3587 value = tls_segment->memsz() - value;
3588 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3591 Relocate_functions<32, false>::rel32(view, value);
3594 // Relocate section data.
3597 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3598 unsigned int sh_type,
3599 const unsigned char* prelocs,
3601 Output_section* output_section,
3602 bool needs_special_offset_handling,
3603 unsigned char* view,
3604 elfcpp::Elf_types<32>::Elf_Addr address,
3605 section_size_type view_size,
3606 const Reloc_symbol_changes* reloc_symbol_changes)
3608 gold_assert(sh_type == elfcpp::SHT_REL);
3610 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
3611 Target_i386::Relocate, gold::Default_comdat_behavior>(
3617 needs_special_offset_handling,
3621 reloc_symbol_changes);
3624 // Return the size of a relocation while scanning during a relocatable
3628 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3629 unsigned int r_type,
3634 case elfcpp::R_386_NONE:
3635 case elfcpp::R_386_GNU_VTINHERIT:
3636 case elfcpp::R_386_GNU_VTENTRY:
3637 case elfcpp::R_386_TLS_GD: // Global-dynamic
3638 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3639 case elfcpp::R_386_TLS_DESC_CALL:
3640 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3641 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3642 case elfcpp::R_386_TLS_IE: // Initial-exec
3643 case elfcpp::R_386_TLS_IE_32:
3644 case elfcpp::R_386_TLS_GOTIE:
3645 case elfcpp::R_386_TLS_LE: // Local-exec
3646 case elfcpp::R_386_TLS_LE_32:
3649 case elfcpp::R_386_32:
3650 case elfcpp::R_386_PC32:
3651 case elfcpp::R_386_GOT32:
3652 case elfcpp::R_386_GOT32X:
3653 case elfcpp::R_386_PLT32:
3654 case elfcpp::R_386_GOTOFF:
3655 case elfcpp::R_386_GOTPC:
3658 case elfcpp::R_386_16:
3659 case elfcpp::R_386_PC16:
3662 case elfcpp::R_386_8:
3663 case elfcpp::R_386_PC8:
3666 // These are relocations which should only be seen by the
3667 // dynamic linker, and should never be seen here.
3668 case elfcpp::R_386_COPY:
3669 case elfcpp::R_386_GLOB_DAT:
3670 case elfcpp::R_386_JUMP_SLOT:
3671 case elfcpp::R_386_RELATIVE:
3672 case elfcpp::R_386_IRELATIVE:
3673 case elfcpp::R_386_TLS_TPOFF:
3674 case elfcpp::R_386_TLS_DTPMOD32:
3675 case elfcpp::R_386_TLS_DTPOFF32:
3676 case elfcpp::R_386_TLS_TPOFF32:
3677 case elfcpp::R_386_TLS_DESC:
3678 object->error(_("unexpected reloc %u in object file"), r_type);
3681 case elfcpp::R_386_32PLT:
3682 case elfcpp::R_386_TLS_GD_32:
3683 case elfcpp::R_386_TLS_GD_PUSH:
3684 case elfcpp::R_386_TLS_GD_CALL:
3685 case elfcpp::R_386_TLS_GD_POP:
3686 case elfcpp::R_386_TLS_LDM_32:
3687 case elfcpp::R_386_TLS_LDM_PUSH:
3688 case elfcpp::R_386_TLS_LDM_CALL:
3689 case elfcpp::R_386_TLS_LDM_POP:
3690 case elfcpp::R_386_USED_BY_INTEL_200:
3692 object->error(_("unsupported reloc %u in object file"), r_type);
3697 // Scan the relocs during a relocatable link.
3700 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3702 Sized_relobj_file<32, false>* object,
3703 unsigned int data_shndx,
3704 unsigned int sh_type,
3705 const unsigned char* prelocs,
3707 Output_section* output_section,
3708 bool needs_special_offset_handling,
3709 size_t local_symbol_count,
3710 const unsigned char* plocal_symbols,
3711 Relocatable_relocs* rr)
3713 gold_assert(sh_type == elfcpp::SHT_REL);
3715 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3716 Relocatable_size_for_reloc> Scan_relocatable_relocs;
3718 gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3719 Scan_relocatable_relocs>(
3727 needs_special_offset_handling,
3733 // Emit relocations for a section.
3736 Target_i386::relocate_relocs(
3737 const Relocate_info<32, false>* relinfo,
3738 unsigned int sh_type,
3739 const unsigned char* prelocs,
3741 Output_section* output_section,
3742 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
3743 const Relocatable_relocs* rr,
3744 unsigned char* view,
3745 elfcpp::Elf_types<32>::Elf_Addr view_address,
3746 section_size_type view_size,
3747 unsigned char* reloc_view,
3748 section_size_type reloc_view_size)
3750 gold_assert(sh_type == elfcpp::SHT_REL);
3752 gold::relocate_relocs<32, false, elfcpp::SHT_REL>(
3757 offset_in_output_section,
3766 // Return the value to use for a dynamic which requires special
3767 // treatment. This is how we support equality comparisons of function
3768 // pointers across shared library boundaries, as described in the
3769 // processor specific ABI supplement.
3772 Target_i386::do_dynsym_value(const Symbol* gsym) const
3774 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3775 return this->plt_address_for_global(gsym);
3778 // Return a string used to fill a code section with nops to take up
3779 // the specified length.
3782 Target_i386::do_code_fill(section_size_type length) const
3786 // Build a jmp instruction to skip over the bytes.
3787 unsigned char jmp[5];
3789 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3790 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3791 + std::string(length - 5, static_cast<char>(0x90)));
3794 // Nop sequences of various lengths.
3795 const char nop1[1] = { '\x90' }; // nop
3796 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
3797 const char nop3[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3798 const char nop4[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3800 const char nop5[5] = { '\x90', '\x8d', '\x74', // nop
3801 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3802 const char nop6[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3803 '\x00', '\x00', '\x00' };
3804 const char nop7[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3805 '\x00', '\x00', '\x00',
3807 const char nop8[8] = { '\x90', '\x8d', '\xb4', // nop
3808 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3810 const char nop9[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3811 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3812 '\x00', '\x00', '\x00' };
3813 const char nop10[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3814 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3815 '\x00', '\x00', '\x00',
3817 const char nop11[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3818 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3819 '\x27', '\x00', '\x00',
3821 const char nop12[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3822 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3823 '\x8d', '\xbf', '\x00',
3824 '\x00', '\x00', '\x00' };
3825 const char nop13[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3826 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3827 '\x8d', '\xbc', '\x27',
3828 '\x00', '\x00', '\x00',
3830 const char nop14[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3831 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3832 '\x00', '\x8d', '\xbc',
3833 '\x27', '\x00', '\x00',
3835 const char nop15[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3836 '\x90', '\x90', '\x90', // nop,nop,nop,...
3837 '\x90', '\x90', '\x90',
3838 '\x90', '\x90', '\x90',
3839 '\x90', '\x90', '\x90' };
3841 const char* nops[16] = {
3843 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3844 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3847 return std::string(nops[length], length);
3850 // Return the value to use for the base of a DW_EH_PE_datarel offset
3851 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3852 // assembler can not write out the difference between two labels in
3853 // different sections, so instead of using a pc-relative value they
3854 // use an offset from the GOT.
3857 Target_i386::do_ehframe_datarel_base() const
3859 gold_assert(this->global_offset_table_ != NULL);
3860 Symbol* sym = this->global_offset_table_;
3861 Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3862 return ssym->value();
3865 // Return whether SYM should be treated as a call to a non-split
3866 // function. We don't want that to be true of a call to a
3867 // get_pc_thunk function.
3870 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3872 return (sym->type() == elfcpp::STT_FUNC
3873 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3876 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3877 // compiled with -fsplit-stack. The function calls non-split-stack
3878 // code. We have to change the function so that it always ensures
3879 // that it has enough stack space to run some random function.
3882 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3883 section_offset_type fnoffset,
3884 section_size_type fnsize,
3885 unsigned char* view,
3886 section_size_type view_size,
3888 std::string* to) const
3890 // The function starts with a comparison of the stack pointer and a
3891 // field in the TCB. This is followed by a jump.
3894 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3897 // We will call __morestack if the carry flag is set after this
3898 // comparison. We turn the comparison into an stc instruction
3900 view[fnoffset] = '\xf9';
3901 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3903 // lea NN(%esp),%ecx
3904 // lea NN(%esp),%edx
3905 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3906 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3909 // This is loading an offset from the stack pointer for a
3910 // comparison. The offset is negative, so we decrease the
3911 // offset by the amount of space we need for the stack. This
3912 // means we will avoid calling __morestack if there happens to
3913 // be plenty of space on the stack already.
3914 unsigned char* pval = view + fnoffset + 3;
3915 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3916 val -= parameters->options().split_stack_adjust_size();
3917 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3921 if (!object->has_no_split_stack())
3922 object->error(_("failed to match split-stack sequence at "
3923 "section %u offset %0zx"),
3924 shndx, static_cast<size_t>(fnoffset));
3928 // We have to change the function so that it calls
3929 // __morestack_non_split instead of __morestack. The former will
3930 // allocate additional stack space.
3931 *from = "__morestack";
3932 *to = "__morestack_non_split";
3935 // The selector for i386 object files. Note this is never instantiated
3936 // directly. It's only used in Target_selector_i386_nacl, below.
3938 class Target_selector_i386 : public Target_selector_freebsd
3941 Target_selector_i386()
3942 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3943 "elf32-i386", "elf32-i386-freebsd",
3948 do_instantiate_target()
3949 { return new Target_i386(); }
3952 // NaCl variant. It uses different PLT contents.
3954 class Output_data_plt_i386_nacl : public Output_data_plt_i386
3957 Output_data_plt_i386_nacl(Layout* layout,
3958 Output_data_got_plt_i386* got_plt,
3959 Output_data_space* got_irelative)
3960 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
3964 virtual unsigned int
3965 do_get_plt_entry_size() const
3966 { return plt_entry_size; }
3969 do_add_eh_frame(Layout* layout)
3971 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
3972 plt_eh_frame_fde, plt_eh_frame_fde_size);
3975 // The size of an entry in the PLT.
3976 static const int plt_entry_size = 64;
3978 // The .eh_frame unwind information for the PLT.
3979 static const int plt_eh_frame_fde_size = 32;
3980 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
3983 class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
3986 Output_data_plt_i386_nacl_exec(Layout* layout,
3987 Output_data_got_plt_i386* got_plt,
3988 Output_data_space* got_irelative)
3989 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
3994 do_fill_first_plt_entry(unsigned char* pov,
3995 elfcpp::Elf_types<32>::Elf_Addr got_address);
3997 virtual unsigned int
3998 do_fill_plt_entry(unsigned char* pov,
3999 elfcpp::Elf_types<32>::Elf_Addr got_address,
4000 unsigned int got_offset,
4001 unsigned int plt_offset,
4002 unsigned int plt_rel_offset);
4005 // The first entry in the PLT for an executable.
4006 static const unsigned char first_plt_entry[plt_entry_size];
4008 // Other entries in the PLT for an executable.
4009 static const unsigned char plt_entry[plt_entry_size];
4012 class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
4015 Output_data_plt_i386_nacl_dyn(Layout* layout,
4016 Output_data_got_plt_i386* got_plt,
4017 Output_data_space* got_irelative)
4018 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4023 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
4025 virtual unsigned int
4026 do_fill_plt_entry(unsigned char* pov,
4027 elfcpp::Elf_types<32>::Elf_Addr,
4028 unsigned int got_offset,
4029 unsigned int plt_offset,
4030 unsigned int plt_rel_offset);
4033 // The first entry in the PLT for a shared object.
4034 static const unsigned char first_plt_entry[plt_entry_size];
4036 // Other entries in the PLT for a shared object.
4037 static const unsigned char plt_entry[plt_entry_size];
4040 class Target_i386_nacl : public Target_i386
4044 : Target_i386(&i386_nacl_info)
4048 virtual Output_data_plt_i386*
4049 do_make_data_plt(Layout* layout,
4050 Output_data_got_plt_i386* got_plt,
4051 Output_data_space* got_irelative,
4055 return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
4057 return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
4061 do_code_fill(section_size_type length) const;
4064 static const Target::Target_info i386_nacl_info;
4067 const Target::Target_info Target_i386_nacl::i386_nacl_info =
4070 false, // is_big_endian
4071 elfcpp::EM_386, // machine_code
4072 false, // has_make_symbol
4073 false, // has_resolve
4074 true, // has_code_fill
4075 true, // is_default_stack_executable
4076 true, // can_icf_inline_merge_sections
4078 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4079 0x20000, // default_text_segment_address
4080 0x10000, // abi_pagesize (overridable by -z max-page-size)
4081 0x10000, // common_pagesize (overridable by -z common-page-size)
4082 true, // isolate_execinstr
4083 0x10000000, // rosegment_gap
4084 elfcpp::SHN_UNDEF, // small_common_shndx
4085 elfcpp::SHN_UNDEF, // large_common_shndx
4086 0, // small_common_section_flags
4087 0, // large_common_section_flags
4088 NULL, // attributes_section
4089 NULL, // attributes_vendor
4090 "_start", // entry_symbol_name
4091 32, // hash_entry_size
4094 #define NACLMASK 0xe0 // 32-byte alignment mask
4097 Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
4099 0xff, 0x35, // pushl contents of memory address
4100 0, 0, 0, 0, // replaced with address of .got + 4
4101 0x8b, 0x0d, // movl contents of address, %ecx
4102 0, 0, 0, 0, // replaced with address of .got + 8
4103 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4104 0xff, 0xe1, // jmp *%ecx
4105 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4106 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4107 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4108 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4109 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4110 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4111 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4112 0x90, 0x90, 0x90, 0x90, 0x90
4116 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4118 elfcpp::Elf_types<32>::Elf_Addr got_address)
4120 memcpy(pov, first_plt_entry, plt_entry_size);
4121 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
4122 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
4125 // The first entry in the PLT for a shared object.
4128 Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
4130 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4131 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4132 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4133 0xff, 0xe1, // jmp *%ecx
4134 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4135 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4136 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4137 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4138 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4139 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4140 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4141 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4142 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4143 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4147 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4149 elfcpp::Elf_types<32>::Elf_Addr)
4151 memcpy(pov, first_plt_entry, plt_entry_size);
4154 // Subsequent entries in the PLT for an executable.
4157 Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
4159 0x8b, 0x0d, // movl contents of address, %ecx */
4160 0, 0, 0, 0, // replaced with address of symbol in .got
4161 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4162 0xff, 0xe1, // jmp *%ecx
4164 // Pad to the next 32-byte boundary with nop instructions.
4166 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4167 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4169 // Lazy GOT entries point here (32-byte aligned).
4170 0x68, // pushl immediate
4171 0, 0, 0, 0, // replaced with offset into relocation table
4172 0xe9, // jmp relative
4173 0, 0, 0, 0, // replaced with offset to start of .plt
4175 // Pad to the next 32-byte boundary with nop instructions.
4176 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4177 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4182 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4184 elfcpp::Elf_types<32>::Elf_Addr got_address,
4185 unsigned int got_offset,
4186 unsigned int plt_offset,
4187 unsigned int plt_rel_offset)
4189 memcpy(pov, plt_entry, plt_entry_size);
4190 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4191 got_address + got_offset);
4192 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4193 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4197 // Subsequent entries in the PLT for a shared object.
4200 Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
4202 0x8b, 0x8b, // movl offset(%ebx), %ecx
4203 0, 0, 0, 0, // replaced with offset of symbol in .got
4204 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4205 0xff, 0xe1, // jmp *%ecx
4207 // Pad to the next 32-byte boundary with nop instructions.
4209 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4210 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4212 // Lazy GOT entries point here (32-byte aligned).
4213 0x68, // pushl immediate
4214 0, 0, 0, 0, // replaced with offset into relocation table.
4215 0xe9, // jmp relative
4216 0, 0, 0, 0, // replaced with offset to start of .plt.
4218 // Pad to the next 32-byte boundary with nop instructions.
4219 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4220 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4225 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4227 elfcpp::Elf_types<32>::Elf_Addr,
4228 unsigned int got_offset,
4229 unsigned int plt_offset,
4230 unsigned int plt_rel_offset)
4232 memcpy(pov, plt_entry, plt_entry_size);
4233 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
4234 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4235 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4240 Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4242 0, 0, 0, 0, // Replaced with offset to .plt.
4243 0, 0, 0, 0, // Replaced with size of .plt.
4244 0, // Augmentation size.
4245 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
4246 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4247 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
4248 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4249 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4250 13, // Block length.
4251 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
4252 elfcpp::DW_OP_breg8, 0, // Push %eip.
4253 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4254 elfcpp::DW_OP_and, // & (%eip & 0x3f).
4255 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4256 elfcpp::DW_OP_ge, // >= ((%eip & 0x3f) >= 0x25)
4257 elfcpp::DW_OP_lit2, // Push 2.
4258 elfcpp::DW_OP_shl, // << (((%eip & 0x3f) >= 0x25) << 2)
4259 elfcpp::DW_OP_plus, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4260 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4264 // Return a string used to fill a code section with nops.
4265 // For NaCl, long NOPs are only valid if they do not cross
4266 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4268 Target_i386_nacl::do_code_fill(section_size_type length) const
4270 return std::string(length, static_cast<char>(0x90));
4273 // The selector for i386-nacl object files.
4275 class Target_selector_i386_nacl
4276 : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
4279 Target_selector_i386_nacl()
4280 : Target_selector_nacl<Target_selector_i386,
4281 Target_i386_nacl>("x86-32",
4287 Target_selector_i386_nacl target_selector_i386;
4289 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4291 class Target_iamcu : public Target_i386
4295 : Target_i386(&iamcu_info)
4299 // Information about this specific target which we pass to the
4300 // general Target structure.
4301 static const Target::Target_info iamcu_info;
4304 const Target::Target_info Target_iamcu::iamcu_info =
4307 false, // is_big_endian
4308 elfcpp::EM_IAMCU, // machine_code
4309 false, // has_make_symbol
4310 false, // has_resolve
4311 true, // has_code_fill
4312 true, // is_default_stack_executable
4313 true, // can_icf_inline_merge_sections
4315 "/usr/lib/libc.so.1", // dynamic_linker
4316 0x08048000, // default_text_segment_address
4317 0x1000, // abi_pagesize (overridable by -z max-page-size)
4318 0x1000, // common_pagesize (overridable by -z common-page-size)
4319 false, // isolate_execinstr
4321 elfcpp::SHN_UNDEF, // small_common_shndx
4322 elfcpp::SHN_UNDEF, // large_common_shndx
4323 0, // small_common_section_flags
4324 0, // large_common_section_flags
4325 NULL, // attributes_section
4326 NULL, // attributes_vendor
4327 "_start", // entry_symbol_name
4328 32, // hash_entry_size
4331 class Target_selector_iamcu : public Target_selector
4334 Target_selector_iamcu()
4335 : Target_selector(elfcpp::EM_IAMCU, 32, false, "elf32-iamcu",
4340 do_instantiate_target()
4341 { return new Target_iamcu(); }
4344 Target_selector_iamcu target_selector_iamcu;
4346 } // End anonymous namespace.