1 // i386.cc -- i386 target support for gold.
3 // Copyright (C) 2006-2020 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 // Scan the relocs for --emit-relocs.
434 emit_relocs_scan(Symbol_table* symtab,
436 Sized_relobj_file<32, false>* object,
437 unsigned int data_shndx,
438 unsigned int sh_type,
439 const unsigned char* prelocs,
441 Output_section* output_section,
442 bool needs_special_offset_handling,
443 size_t local_symbol_count,
444 const unsigned char* plocal_syms,
445 Relocatable_relocs* rr);
447 // Emit relocations for a section.
449 relocate_relocs(const Relocate_info<32, false>*,
450 unsigned int sh_type,
451 const unsigned char* prelocs,
453 Output_section* output_section,
454 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
456 elfcpp::Elf_types<32>::Elf_Addr view_address,
457 section_size_type view_size,
458 unsigned char* reloc_view,
459 section_size_type reloc_view_size);
461 // Return a string used to fill a code section with nops.
463 do_code_fill(section_size_type length) const;
465 // Return whether SYM is defined by the ABI.
467 do_is_defined_by_abi(const Symbol* sym) const
468 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
470 // Return whether a symbol name implies a local label. The UnixWare
471 // 2.1 cc generates temporary symbols that start with .X, so we
472 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
473 // If so, we should move the .X recognition into
474 // Target::do_is_local_label_name.
476 do_is_local_label_name(const char* name) const
478 if (name[0] == '.' && name[1] == 'X')
480 return Target::do_is_local_label_name(name);
483 // Return the PLT address to use for a global symbol.
485 do_plt_address_for_global(const Symbol* gsym) const
486 { return this->plt_section()->address_for_global(gsym); }
489 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
490 { return this->plt_section()->address_for_local(relobj, symndx); }
492 // We can tell whether we take the address of a function.
494 do_can_check_for_function_pointers() const
497 // Return the base for a DW_EH_PE_datarel encoding.
499 do_ehframe_datarel_base() const;
501 // Return whether SYM is call to a non-split function.
503 do_is_call_to_non_split(const Symbol* sym, const unsigned char*,
504 const unsigned char*, section_size_type) const;
506 // Adjust -fsplit-stack code which calls non-split-stack code.
508 do_calls_non_split(Relobj* object, unsigned int shndx,
509 section_offset_type fnoffset, section_size_type fnsize,
510 const unsigned char* prelocs, size_t reloc_count,
511 unsigned char* view, section_size_type view_size,
512 std::string* from, std::string* to) const;
514 // Return the size of the GOT section.
518 gold_assert(this->got_ != NULL);
519 return this->got_->data_size();
522 // Return the number of entries in the GOT.
524 got_entry_count() const
526 if (this->got_ == NULL)
528 return this->got_size() / 4;
531 // Return the number of entries in the PLT.
533 plt_entry_count() const;
535 // Return the offset of the first non-reserved PLT entry.
537 first_plt_entry_offset() const;
539 // Return the size of each PLT entry.
541 plt_entry_size() const;
544 // Instantiate the plt_ member.
545 // This chooses the right PLT flavor for an executable or a shared object.
546 Output_data_plt_i386*
547 make_data_plt(Layout* layout,
548 Output_data_got_plt_i386* got_plt,
549 Output_data_space* got_irelative,
551 { return this->do_make_data_plt(layout, got_plt, got_irelative, dyn); }
553 virtual Output_data_plt_i386*
554 do_make_data_plt(Layout* layout,
555 Output_data_got_plt_i386* got_plt,
556 Output_data_space* got_irelative,
560 return new Output_data_plt_i386_dyn(layout, got_plt, got_irelative);
562 return new Output_data_plt_i386_exec(layout, got_plt, got_irelative);
566 // The class which scans relocations.
571 get_reference_flags(unsigned int r_type);
574 local(Symbol_table* symtab, Layout* layout, Target_i386* target,
575 Sized_relobj_file<32, false>* object,
576 unsigned int data_shndx,
577 Output_section* output_section,
578 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
579 const elfcpp::Sym<32, false>& lsym,
583 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
584 Sized_relobj_file<32, false>* object,
585 unsigned int data_shndx,
586 Output_section* output_section,
587 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
591 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
593 Sized_relobj_file<32, false>* object,
594 unsigned int data_shndx,
595 Output_section* output_section,
596 const elfcpp::Rel<32, false>& reloc,
598 const elfcpp::Sym<32, false>& lsym);
601 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
603 Sized_relobj_file<32, false>* object,
604 unsigned int data_shndx,
605 Output_section* output_section,
606 const elfcpp::Rel<32, false>& reloc,
611 possible_function_pointer_reloc(unsigned int r_type);
614 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
615 unsigned int r_type);
618 unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
621 unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
625 // The class which implements relocation.
630 : skip_call_tls_get_addr_(false),
631 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
636 if (this->skip_call_tls_get_addr_)
638 // FIXME: This needs to specify the location somehow.
639 gold_error(_("missing expected TLS relocation"));
643 // Return whether the static relocation needs to be applied.
645 should_apply_static_reloc(const Sized_symbol<32>* gsym,
648 Output_section* output_section);
650 // Do a relocation. Return false if the caller should not issue
651 // any warnings about this relocation.
653 relocate(const Relocate_info<32, false>*, unsigned int,
654 Target_i386*, Output_section*, size_t, const unsigned char*,
655 const Sized_symbol<32>*, const Symbol_value<32>*,
656 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
660 // Do a TLS relocation.
662 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
663 size_t relnum, const elfcpp::Rel<32, false>&,
664 unsigned int r_type, const Sized_symbol<32>*,
665 const Symbol_value<32>*,
666 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
669 // Do a TLS General-Dynamic to Initial-Exec transition.
671 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
672 const elfcpp::Rel<32, false>&, unsigned int r_type,
673 elfcpp::Elf_types<32>::Elf_Addr value,
675 section_size_type view_size);
677 // Do a TLS General-Dynamic to Local-Exec transition.
679 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
680 Output_segment* tls_segment,
681 const elfcpp::Rel<32, false>&, unsigned int r_type,
682 elfcpp::Elf_types<32>::Elf_Addr value,
684 section_size_type view_size);
686 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
689 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
690 const elfcpp::Rel<32, false>&, unsigned int r_type,
691 elfcpp::Elf_types<32>::Elf_Addr value,
693 section_size_type view_size);
695 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
698 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
699 Output_segment* tls_segment,
700 const elfcpp::Rel<32, false>&, unsigned int r_type,
701 elfcpp::Elf_types<32>::Elf_Addr value,
703 section_size_type view_size);
705 // Do a TLS Local-Dynamic to Local-Exec transition.
707 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
708 Output_segment* tls_segment,
709 const elfcpp::Rel<32, false>&, unsigned int r_type,
710 elfcpp::Elf_types<32>::Elf_Addr value,
712 section_size_type view_size);
714 // Do a TLS Initial-Exec to Local-Exec transition.
716 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
717 Output_segment* tls_segment,
718 const elfcpp::Rel<32, false>&, unsigned int r_type,
719 elfcpp::Elf_types<32>::Elf_Addr value,
721 section_size_type view_size);
723 // We need to keep track of which type of local dynamic relocation
724 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
725 enum Local_dynamic_type
732 // This is set if we should skip the next reloc, which should be a
733 // PLT32 reloc against ___tls_get_addr.
734 bool skip_call_tls_get_addr_;
735 // The type of local dynamic relocation we have seen in the section
736 // being relocated, if any.
737 Local_dynamic_type local_dynamic_type_;
740 // A class for inquiring about properties of a relocation,
741 // used while scanning relocs during a relocatable link and
742 // garbage collection.
743 class Classify_reloc :
744 public gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
747 typedef Reloc_types<elfcpp::SHT_REL, 32, false>::Reloc Reltype;
749 // Return the explicit addend of the relocation (return 0 for SHT_REL).
750 static elfcpp::Elf_types<32>::Elf_Swxword
751 get_r_addend(const Reltype*)
754 // Return the size of the addend of the relocation (only used for SHT_REL).
756 get_size_for_reloc(unsigned int, Relobj*);
759 // Adjust TLS relocation type based on the options and whether this
760 // is a local symbol.
761 static tls::Tls_optimization
762 optimize_tls_reloc(bool is_final, int r_type);
764 // Check if relocation against this symbol is a candidate for
766 // mov foo@GOT(%reg), %reg
768 // lea foo@GOTOFF(%reg), %reg.
770 can_convert_mov_to_lea(const Symbol* gsym)
772 gold_assert(gsym != NULL);
773 return (gsym->type() != elfcpp::STT_GNU_IFUNC
774 && !gsym->is_undefined ()
775 && !gsym->is_from_dynobj()
776 && !gsym->is_preemptible()
777 && (!parameters->options().shared()
778 || (gsym->visibility() != elfcpp::STV_DEFAULT
779 && gsym->visibility() != elfcpp::STV_PROTECTED)
780 || parameters->options().Bsymbolic())
781 && strcmp(gsym->name(), "_DYNAMIC") != 0);
784 // Get the GOT section, creating it if necessary.
785 Output_data_got<32, false>*
786 got_section(Symbol_table*, Layout*);
788 // Get the GOT PLT section.
789 Output_data_got_plt_i386*
790 got_plt_section() const
792 gold_assert(this->got_plt_ != NULL);
793 return this->got_plt_;
796 // Get the GOT section for TLSDESC entries.
797 Output_data_got<32, false>*
798 got_tlsdesc_section() const
800 gold_assert(this->got_tlsdesc_ != NULL);
801 return this->got_tlsdesc_;
804 // Create the PLT section.
806 make_plt_section(Symbol_table* symtab, Layout* layout);
808 // Create a PLT entry for a global symbol.
810 make_plt_entry(Symbol_table*, Layout*, Symbol*);
812 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
814 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
815 Sized_relobj_file<32, false>* relobj,
816 unsigned int local_sym_index);
818 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
820 define_tls_base_symbol(Symbol_table*, Layout*);
822 // Create a GOT entry for the TLS module index.
824 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
825 Sized_relobj_file<32, false>* object);
827 // Get the PLT section.
828 Output_data_plt_i386*
831 gold_assert(this->plt_ != NULL);
835 // Get the dynamic reloc section, creating it if necessary.
837 rel_dyn_section(Layout*);
839 // Get the section to use for TLS_DESC relocations.
841 rel_tls_desc_section(Layout*) const;
843 // Get the section to use for IRELATIVE relocations.
845 rel_irelative_section(Layout*);
847 // Add a potential copy relocation.
849 copy_reloc(Symbol_table* symtab, Layout* layout,
850 Sized_relobj_file<32, false>* object,
851 unsigned int shndx, Output_section* output_section,
852 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
854 unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
855 this->copy_relocs_.copy_reloc(symtab, layout,
856 symtab->get_sized_symbol<32>(sym),
857 object, shndx, output_section,
858 r_type, reloc.get_r_offset(), 0,
859 this->rel_dyn_section(layout));
862 // Information about this specific target which we pass to the
863 // general Target structure.
864 static const Target::Target_info i386_info;
866 // The types of GOT entries needed for this platform.
867 // These values are exposed to the ABI in an incremental link.
868 // Do not renumber existing values without changing the version
869 // number of the .gnu_incremental_inputs section.
872 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
873 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
874 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
875 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
876 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
880 Output_data_got<32, false>* got_;
882 Output_data_plt_i386* plt_;
883 // The GOT PLT section.
884 Output_data_got_plt_i386* got_plt_;
885 // The GOT section for IRELATIVE relocations.
886 Output_data_space* got_irelative_;
887 // The GOT section for TLSDESC relocations.
888 Output_data_got<32, false>* got_tlsdesc_;
889 // The _GLOBAL_OFFSET_TABLE_ symbol.
890 Symbol* global_offset_table_;
891 // The dynamic reloc section.
892 Reloc_section* rel_dyn_;
893 // The section to use for IRELATIVE relocs.
894 Reloc_section* rel_irelative_;
895 // Relocs saved to avoid a COPY reloc.
896 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
897 // Offset of the GOT entry for the TLS module index.
898 unsigned int got_mod_index_offset_;
899 // True if the _TLS_MODULE_BASE_ symbol has been defined.
900 bool tls_base_symbol_defined_;
903 const Target::Target_info Target_i386::i386_info =
906 false, // is_big_endian
907 elfcpp::EM_386, // machine_code
908 false, // has_make_symbol
909 false, // has_resolve
910 true, // has_code_fill
911 true, // is_default_stack_executable
912 true, // can_icf_inline_merge_sections
914 "/usr/lib/libc.so.1", // dynamic_linker
915 0x08048000, // default_text_segment_address
916 0x1000, // abi_pagesize (overridable by -z max-page-size)
917 0x1000, // common_pagesize (overridable by -z common-page-size)
918 false, // isolate_execinstr
920 elfcpp::SHN_UNDEF, // small_common_shndx
921 elfcpp::SHN_UNDEF, // large_common_shndx
922 0, // small_common_section_flags
923 0, // large_common_section_flags
924 NULL, // attributes_section
925 NULL, // attributes_vendor
926 "_start", // entry_symbol_name
927 32, // hash_entry_size
928 elfcpp::SHT_PROGBITS, // unwind_section_type
931 // Get the GOT section, creating it if necessary.
933 Output_data_got<32, false>*
934 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
936 if (this->got_ == NULL)
938 gold_assert(symtab != NULL && layout != NULL);
940 this->got_ = new Output_data_got<32, false>();
942 // When using -z now, we can treat .got.plt as a relro section.
943 // Without -z now, it is modified after program startup by lazy
945 bool is_got_plt_relro = parameters->options().now();
946 Output_section_order got_order = (is_got_plt_relro
949 Output_section_order got_plt_order = (is_got_plt_relro
951 : ORDER_NON_RELRO_FIRST);
953 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
955 | elfcpp::SHF_WRITE),
956 this->got_, got_order, true);
958 this->got_plt_ = new Output_data_got_plt_i386(layout);
959 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
961 | elfcpp::SHF_WRITE),
962 this->got_plt_, got_plt_order,
965 // The first three entries are reserved.
966 this->got_plt_->set_current_data_size(3 * 4);
968 if (!is_got_plt_relro)
970 // Those bytes can go into the relro segment.
971 layout->increase_relro(3 * 4);
974 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
975 this->global_offset_table_ =
976 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
977 Symbol_table::PREDEFINED,
979 0, 0, elfcpp::STT_OBJECT,
981 elfcpp::STV_HIDDEN, 0,
984 // If there are any IRELATIVE relocations, they get GOT entries
985 // in .got.plt after the jump slot relocations.
986 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
987 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
989 | elfcpp::SHF_WRITE),
990 this->got_irelative_,
991 got_plt_order, is_got_plt_relro);
993 // If there are any TLSDESC relocations, they get GOT entries in
994 // .got.plt after the jump slot entries.
995 this->got_tlsdesc_ = new Output_data_got<32, false>();
996 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
998 | elfcpp::SHF_WRITE),
1000 got_plt_order, is_got_plt_relro);
1006 // Get the dynamic reloc section, creating it if necessary.
1008 Target_i386::Reloc_section*
1009 Target_i386::rel_dyn_section(Layout* layout)
1011 if (this->rel_dyn_ == NULL)
1013 gold_assert(layout != NULL);
1014 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
1015 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1016 elfcpp::SHF_ALLOC, this->rel_dyn_,
1017 ORDER_DYNAMIC_RELOCS, false);
1019 return this->rel_dyn_;
1022 // Get the section to use for IRELATIVE relocs, creating it if
1023 // necessary. These go in .rel.dyn, but only after all other dynamic
1024 // relocations. They need to follow the other dynamic relocations so
1025 // that they can refer to global variables initialized by those
1028 Target_i386::Reloc_section*
1029 Target_i386::rel_irelative_section(Layout* layout)
1031 if (this->rel_irelative_ == NULL)
1033 // Make sure we have already create the dynamic reloc section.
1034 this->rel_dyn_section(layout);
1035 this->rel_irelative_ = new Reloc_section(false);
1036 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1037 elfcpp::SHF_ALLOC, this->rel_irelative_,
1038 ORDER_DYNAMIC_RELOCS, false);
1039 gold_assert(this->rel_dyn_->output_section()
1040 == this->rel_irelative_->output_section());
1042 return this->rel_irelative_;
1045 // Write the first three reserved words of the .got.plt section.
1046 // The remainder of the section is written while writing the PLT
1047 // in Output_data_plt_i386::do_write.
1050 Output_data_got_plt_i386::do_write(Output_file* of)
1052 // The first entry in the GOT is the address of the .dynamic section
1053 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1054 // We saved space for them when we created the section in
1055 // Target_i386::got_section.
1056 const off_t got_file_offset = this->offset();
1057 gold_assert(this->data_size() >= 12);
1058 unsigned char* const got_view = of->get_output_view(got_file_offset, 12);
1059 Output_section* dynamic = this->layout_->dynamic_section();
1060 uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1061 elfcpp::Swap<32, false>::writeval(got_view, dynamic_addr);
1062 memset(got_view + 4, 0, 8);
1063 of->write_output_view(got_file_offset, 12, got_view);
1066 // Create the PLT section. The ordinary .got section is an argument,
1067 // since we need to refer to the start. We also create our own .got
1068 // section just for PLT entries.
1070 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
1072 Output_data_got_plt_i386* got_plt,
1073 Output_data_space* got_irelative)
1074 : Output_section_data(addralign),
1075 tls_desc_rel_(NULL), irelative_rel_(NULL), got_plt_(got_plt),
1076 got_irelative_(got_irelative), count_(0), irelative_count_(0),
1077 global_ifuncs_(), local_ifuncs_()
1079 this->rel_ = new Reloc_section(false);
1080 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1081 elfcpp::SHF_ALLOC, this->rel_,
1082 ORDER_DYNAMIC_PLT_RELOCS, false);
1086 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
1088 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1089 // linker, and so do we.
1093 // Add an entry to the PLT.
1096 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
1099 gold_assert(!gsym->has_plt_offset());
1101 // Every PLT entry needs a reloc.
1102 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1103 && gsym->can_use_relative_reloc(false))
1105 gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
1106 ++this->irelative_count_;
1107 section_offset_type got_offset =
1108 this->got_irelative_->current_data_size();
1109 this->got_irelative_->set_current_data_size(got_offset + 4);
1110 Reloc_section* rel = this->rel_irelative(symtab, layout);
1111 rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
1112 this->got_irelative_, got_offset);
1113 struct Global_ifunc gi;
1115 gi.got_offset = got_offset;
1116 this->global_ifuncs_.push_back(gi);
1120 // When setting the PLT offset we skip the initial reserved PLT
1122 gsym->set_plt_offset((this->count_ + 1) * this->get_plt_entry_size());
1126 section_offset_type got_offset = this->got_plt_->current_data_size();
1128 // Every PLT entry needs a GOT entry which points back to the
1129 // PLT entry (this will be changed by the dynamic linker,
1130 // normally lazily when the function is called).
1131 this->got_plt_->set_current_data_size(got_offset + 4);
1133 gsym->set_needs_dynsym_entry();
1134 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
1138 // Note that we don't need to save the symbol. The contents of the
1139 // PLT are independent of which symbols are used. The symbols only
1140 // appear in the relocations.
1143 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1147 Output_data_plt_i386::add_local_ifunc_entry(
1148 Symbol_table* symtab,
1150 Sized_relobj_file<32, false>* relobj,
1151 unsigned int local_sym_index)
1153 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1154 ++this->irelative_count_;
1156 section_offset_type got_offset = this->got_irelative_->current_data_size();
1158 // Every PLT entry needs a GOT entry which points back to the PLT
1160 this->got_irelative_->set_current_data_size(got_offset + 4);
1162 // Every PLT entry needs a reloc.
1163 Reloc_section* rel = this->rel_irelative(symtab, layout);
1164 rel->add_symbolless_local_addend(relobj, local_sym_index,
1165 elfcpp::R_386_IRELATIVE,
1166 this->got_irelative_, got_offset);
1168 struct Local_ifunc li;
1170 li.local_sym_index = local_sym_index;
1171 li.got_offset = got_offset;
1172 this->local_ifuncs_.push_back(li);
1177 // Return where the TLS_DESC relocations should go, creating it if
1178 // necessary. These follow the JUMP_SLOT relocations.
1180 Output_data_plt_i386::Reloc_section*
1181 Output_data_plt_i386::rel_tls_desc(Layout* layout)
1183 if (this->tls_desc_rel_ == NULL)
1185 this->tls_desc_rel_ = new Reloc_section(false);
1186 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1187 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
1188 ORDER_DYNAMIC_PLT_RELOCS, false);
1189 gold_assert(this->tls_desc_rel_->output_section()
1190 == this->rel_->output_section());
1192 return this->tls_desc_rel_;
1195 // Return where the IRELATIVE relocations should go in the PLT. These
1196 // follow the JUMP_SLOT and TLS_DESC relocations.
1198 Output_data_plt_i386::Reloc_section*
1199 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
1201 if (this->irelative_rel_ == NULL)
1203 // Make sure we have a place for the TLS_DESC relocations, in
1204 // case we see any later on.
1205 this->rel_tls_desc(layout);
1206 this->irelative_rel_ = new Reloc_section(false);
1207 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1208 elfcpp::SHF_ALLOC, this->irelative_rel_,
1209 ORDER_DYNAMIC_PLT_RELOCS, false);
1210 gold_assert(this->irelative_rel_->output_section()
1211 == this->rel_->output_section());
1213 if (parameters->doing_static_link())
1215 // A statically linked executable will only have a .rel.plt
1216 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1217 // symbols. The library will use these symbols to locate
1218 // the IRELATIVE relocs at program startup time.
1219 symtab->define_in_output_data("__rel_iplt_start", NULL,
1220 Symbol_table::PREDEFINED,
1221 this->irelative_rel_, 0, 0,
1222 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1223 elfcpp::STV_HIDDEN, 0, false, true);
1224 symtab->define_in_output_data("__rel_iplt_end", NULL,
1225 Symbol_table::PREDEFINED,
1226 this->irelative_rel_, 0, 0,
1227 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1228 elfcpp::STV_HIDDEN, 0, true, true);
1231 return this->irelative_rel_;
1234 // Return the PLT address to use for a global symbol.
1237 Output_data_plt_i386::address_for_global(const Symbol* gsym)
1239 uint64_t offset = 0;
1240 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1241 && gsym->can_use_relative_reloc(false))
1242 offset = (this->count_ + 1) * this->get_plt_entry_size();
1243 return this->address() + offset + gsym->plt_offset();
1246 // Return the PLT address to use for a local symbol. These are always
1247 // IRELATIVE relocs.
1250 Output_data_plt_i386::address_for_local(const Relobj* object,
1253 return (this->address()
1254 + (this->count_ + 1) * this->get_plt_entry_size()
1255 + object->local_plt_offset(r_sym));
1258 // The first entry in the PLT for an executable.
1260 const unsigned char Output_data_plt_i386_exec::first_plt_entry[plt_entry_size] =
1262 0xff, 0x35, // pushl contents of memory address
1263 0, 0, 0, 0, // replaced with address of .got + 4
1264 0xff, 0x25, // jmp indirect
1265 0, 0, 0, 0, // replaced with address of .got + 8
1266 0, 0, 0, 0 // unused
1270 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1272 elfcpp::Elf_types<32>::Elf_Addr got_address)
1274 memcpy(pov, first_plt_entry, plt_entry_size);
1275 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1276 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1279 // The first entry in the PLT for a shared object.
1281 const unsigned char Output_data_plt_i386_dyn::first_plt_entry[plt_entry_size] =
1283 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1284 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1285 0, 0, 0, 0 // unused
1289 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1291 elfcpp::Elf_types<32>::Elf_Addr)
1293 memcpy(pov, first_plt_entry, plt_entry_size);
1296 // Subsequent entries in the PLT for an executable.
1298 const unsigned char Output_data_plt_i386_exec::plt_entry[plt_entry_size] =
1300 0xff, 0x25, // jmp indirect
1301 0, 0, 0, 0, // replaced with address of symbol in .got
1302 0x68, // pushl immediate
1303 0, 0, 0, 0, // replaced with offset into relocation table
1304 0xe9, // jmp relative
1305 0, 0, 0, 0 // replaced with offset to start of .plt
1309 Output_data_plt_i386_exec::do_fill_plt_entry(
1311 elfcpp::Elf_types<32>::Elf_Addr got_address,
1312 unsigned int got_offset,
1313 unsigned int plt_offset,
1314 unsigned int plt_rel_offset)
1316 memcpy(pov, plt_entry, plt_entry_size);
1317 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1318 got_address + got_offset);
1319 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1320 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1324 // Subsequent entries in the PLT for a shared object.
1326 const unsigned char Output_data_plt_i386_dyn::plt_entry[plt_entry_size] =
1328 0xff, 0xa3, // jmp *offset(%ebx)
1329 0, 0, 0, 0, // replaced with offset of symbol in .got
1330 0x68, // pushl immediate
1331 0, 0, 0, 0, // replaced with offset into relocation table
1332 0xe9, // jmp relative
1333 0, 0, 0, 0 // replaced with offset to start of .plt
1337 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
1338 elfcpp::Elf_types<32>::Elf_Addr,
1339 unsigned int got_offset,
1340 unsigned int plt_offset,
1341 unsigned int plt_rel_offset)
1343 memcpy(pov, plt_entry, plt_entry_size);
1344 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1345 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1346 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1350 // The .eh_frame unwind information for the PLT.
1353 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1356 'z', // Augmentation: augmentation size included.
1357 'R', // Augmentation: FDE encoding included.
1358 '\0', // End of augmentation string.
1359 1, // Code alignment factor.
1360 0x7c, // Data alignment factor.
1361 8, // Return address column.
1362 1, // Augmentation size.
1363 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1364 | elfcpp::DW_EH_PE_sdata4),
1365 elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1366 elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1367 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1372 Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1374 0, 0, 0, 0, // Replaced with offset to .plt.
1375 0, 0, 0, 0, // Replaced with size of .plt.
1376 0, // Augmentation size.
1377 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
1378 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1379 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
1380 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1381 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1382 11, // Block length.
1383 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
1384 elfcpp::DW_OP_breg8, 0, // Push %eip.
1385 elfcpp::DW_OP_lit15, // Push 0xf.
1386 elfcpp::DW_OP_and, // & (%eip & 0xf).
1387 elfcpp::DW_OP_lit11, // Push 0xb.
1388 elfcpp::DW_OP_ge, // >= ((%eip & 0xf) >= 0xb)
1389 elfcpp::DW_OP_lit2, // Push 2.
1390 elfcpp::DW_OP_shl, // << (((%eip & 0xf) >= 0xb) << 2)
1391 elfcpp::DW_OP_plus, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1392 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1398 // Write out the PLT. This uses the hand-coded instructions above,
1399 // and adjusts them as needed. This is all specified by the i386 ELF
1400 // Processor Supplement.
1403 Output_data_plt_i386::do_write(Output_file* of)
1405 const off_t offset = this->offset();
1406 const section_size_type oview_size =
1407 convert_to_section_size_type(this->data_size());
1408 unsigned char* const oview = of->get_output_view(offset, oview_size);
1410 const off_t got_file_offset = this->got_plt_->offset();
1411 gold_assert(parameters->incremental_update()
1412 || (got_file_offset + this->got_plt_->data_size()
1413 == this->got_irelative_->offset()));
1414 const section_size_type got_size =
1415 convert_to_section_size_type(this->got_plt_->data_size()
1416 + this->got_irelative_->data_size());
1418 unsigned char* const got_view = of->get_output_view(got_file_offset,
1421 unsigned char* pov = oview;
1423 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1424 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1426 this->fill_first_plt_entry(pov, got_address);
1427 pov += this->get_plt_entry_size();
1429 // The first three entries in the GOT are reserved, and are written
1430 // by Output_data_got_plt_i386::do_write.
1431 unsigned char* got_pov = got_view + 12;
1433 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1435 unsigned int plt_offset = this->get_plt_entry_size();
1436 unsigned int plt_rel_offset = 0;
1437 unsigned int got_offset = 12;
1438 const unsigned int count = this->count_ + this->irelative_count_;
1439 for (unsigned int i = 0;
1442 pov += this->get_plt_entry_size(),
1444 plt_offset += this->get_plt_entry_size(),
1445 plt_rel_offset += rel_size,
1448 // Set and adjust the PLT entry itself.
1449 unsigned int lazy_offset = this->fill_plt_entry(pov,
1455 // Set the entry in the GOT.
1456 elfcpp::Swap<32, false>::writeval(got_pov,
1457 plt_address + plt_offset + lazy_offset);
1460 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1461 // the GOT to point to the actual symbol value, rather than point to
1462 // the PLT entry. That will let the dynamic linker call the right
1463 // function when resolving IRELATIVE relocations.
1464 unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1465 for (std::vector<Global_ifunc>::const_iterator p =
1466 this->global_ifuncs_.begin();
1467 p != this->global_ifuncs_.end();
1470 const Sized_symbol<32>* ssym =
1471 static_cast<const Sized_symbol<32>*>(p->sym);
1472 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1476 for (std::vector<Local_ifunc>::const_iterator p =
1477 this->local_ifuncs_.begin();
1478 p != this->local_ifuncs_.end();
1481 const Symbol_value<32>* psymval =
1482 p->object->local_symbol(p->local_sym_index);
1483 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1484 psymval->value(p->object, 0));
1487 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1488 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1490 of->write_output_view(offset, oview_size, oview);
1491 of->write_output_view(got_file_offset, got_size, got_view);
1494 // Create the PLT section.
1497 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1499 if (this->plt_ == NULL)
1501 // Create the GOT sections first.
1502 this->got_section(symtab, layout);
1504 const bool dyn = parameters->options().output_is_position_independent();
1505 this->plt_ = this->make_data_plt(layout,
1507 this->got_irelative_,
1510 // Add unwind information if requested.
1511 if (parameters->options().ld_generated_unwind_info())
1512 this->plt_->add_eh_frame(layout);
1514 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1516 | elfcpp::SHF_EXECINSTR),
1517 this->plt_, ORDER_PLT, false);
1519 // Make the sh_info field of .rel.plt point to .plt.
1520 Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1521 rel_plt_os->set_info_section(this->plt_->output_section());
1525 // Create a PLT entry for a global symbol.
1528 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1530 if (gsym->has_plt_offset())
1532 if (this->plt_ == NULL)
1533 this->make_plt_section(symtab, layout);
1534 this->plt_->add_entry(symtab, layout, gsym);
1537 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1540 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1541 Sized_relobj_file<32, false>* relobj,
1542 unsigned int local_sym_index)
1544 if (relobj->local_has_plt_offset(local_sym_index))
1546 if (this->plt_ == NULL)
1547 this->make_plt_section(symtab, layout);
1548 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1551 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1554 // Return the number of entries in the PLT.
1557 Target_i386::plt_entry_count() const
1559 if (this->plt_ == NULL)
1561 return this->plt_->entry_count();
1564 // Return the offset of the first non-reserved PLT entry.
1567 Target_i386::first_plt_entry_offset() const
1569 if (this->plt_ == NULL)
1571 return this->plt_->first_plt_entry_offset();
1574 // Return the size of each PLT entry.
1577 Target_i386::plt_entry_size() const
1579 if (this->plt_ == NULL)
1581 return this->plt_->get_plt_entry_size();
1584 // Get the section to use for TLS_DESC relocations.
1586 Target_i386::Reloc_section*
1587 Target_i386::rel_tls_desc_section(Layout* layout) const
1589 return this->plt_section()->rel_tls_desc(layout);
1592 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1595 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1597 if (this->tls_base_symbol_defined_)
1600 Output_segment* tls_segment = layout->tls_segment();
1601 if (tls_segment != NULL)
1603 bool is_exec = parameters->options().output_is_executable();
1604 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1605 Symbol_table::PREDEFINED,
1609 elfcpp::STV_HIDDEN, 0,
1611 ? Symbol::SEGMENT_END
1612 : Symbol::SEGMENT_START),
1615 this->tls_base_symbol_defined_ = true;
1618 // Create a GOT entry for the TLS module index.
1621 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1622 Sized_relobj_file<32, false>* object)
1624 if (this->got_mod_index_offset_ == -1U)
1626 gold_assert(symtab != NULL && layout != NULL && object != NULL);
1627 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1628 Output_data_got<32, false>* got = this->got_section(symtab, layout);
1629 unsigned int got_offset = got->add_constant(0);
1630 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1632 got->add_constant(0);
1633 this->got_mod_index_offset_ = got_offset;
1635 return this->got_mod_index_offset_;
1638 // Optimize the TLS relocation type based on what we know about the
1639 // symbol. IS_FINAL is true if the final address of this symbol is
1640 // known at link time.
1642 tls::Tls_optimization
1643 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1645 // If we are generating a shared library, then we can't do anything
1647 if (parameters->options().shared())
1648 return tls::TLSOPT_NONE;
1652 case elfcpp::R_386_TLS_GD:
1653 case elfcpp::R_386_TLS_GOTDESC:
1654 case elfcpp::R_386_TLS_DESC_CALL:
1655 // These are General-Dynamic which permits fully general TLS
1656 // access. Since we know that we are generating an executable,
1657 // we can convert this to Initial-Exec. If we also know that
1658 // this is a local symbol, we can further switch to Local-Exec.
1660 return tls::TLSOPT_TO_LE;
1661 return tls::TLSOPT_TO_IE;
1663 case elfcpp::R_386_TLS_LDM:
1664 // This is Local-Dynamic, which refers to a local symbol in the
1665 // dynamic TLS block. Since we know that we generating an
1666 // executable, we can switch to Local-Exec.
1667 return tls::TLSOPT_TO_LE;
1669 case elfcpp::R_386_TLS_LDO_32:
1670 // Another type of Local-Dynamic relocation.
1671 return tls::TLSOPT_TO_LE;
1673 case elfcpp::R_386_TLS_IE:
1674 case elfcpp::R_386_TLS_GOTIE:
1675 case elfcpp::R_386_TLS_IE_32:
1676 // These are Initial-Exec relocs which get the thread offset
1677 // from the GOT. If we know that we are linking against the
1678 // local symbol, we can switch to Local-Exec, which links the
1679 // thread offset into the instruction.
1681 return tls::TLSOPT_TO_LE;
1682 return tls::TLSOPT_NONE;
1684 case elfcpp::R_386_TLS_LE:
1685 case elfcpp::R_386_TLS_LE_32:
1686 // When we already have Local-Exec, there is nothing further we
1688 return tls::TLSOPT_NONE;
1695 // Get the Reference_flags for a particular relocation.
1698 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1702 case elfcpp::R_386_NONE:
1703 case elfcpp::R_386_GNU_VTINHERIT:
1704 case elfcpp::R_386_GNU_VTENTRY:
1705 case elfcpp::R_386_GOTPC:
1706 // No symbol reference.
1709 case elfcpp::R_386_32:
1710 case elfcpp::R_386_16:
1711 case elfcpp::R_386_8:
1712 return Symbol::ABSOLUTE_REF;
1714 case elfcpp::R_386_PC32:
1715 case elfcpp::R_386_PC16:
1716 case elfcpp::R_386_PC8:
1717 case elfcpp::R_386_GOTOFF:
1718 return Symbol::RELATIVE_REF;
1720 case elfcpp::R_386_PLT32:
1721 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1723 case elfcpp::R_386_GOT32:
1724 case elfcpp::R_386_GOT32X:
1726 return Symbol::ABSOLUTE_REF;
1728 case elfcpp::R_386_TLS_GD: // Global-dynamic
1729 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1730 case elfcpp::R_386_TLS_DESC_CALL:
1731 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1732 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1733 case elfcpp::R_386_TLS_IE: // Initial-exec
1734 case elfcpp::R_386_TLS_IE_32:
1735 case elfcpp::R_386_TLS_GOTIE:
1736 case elfcpp::R_386_TLS_LE: // Local-exec
1737 case elfcpp::R_386_TLS_LE_32:
1738 return Symbol::TLS_REF;
1740 case elfcpp::R_386_COPY:
1741 case elfcpp::R_386_GLOB_DAT:
1742 case elfcpp::R_386_JUMP_SLOT:
1743 case elfcpp::R_386_RELATIVE:
1744 case elfcpp::R_386_IRELATIVE:
1745 case elfcpp::R_386_TLS_TPOFF:
1746 case elfcpp::R_386_TLS_DTPMOD32:
1747 case elfcpp::R_386_TLS_DTPOFF32:
1748 case elfcpp::R_386_TLS_TPOFF32:
1749 case elfcpp::R_386_TLS_DESC:
1750 case elfcpp::R_386_32PLT:
1751 case elfcpp::R_386_TLS_GD_32:
1752 case elfcpp::R_386_TLS_GD_PUSH:
1753 case elfcpp::R_386_TLS_GD_CALL:
1754 case elfcpp::R_386_TLS_GD_POP:
1755 case elfcpp::R_386_TLS_LDM_32:
1756 case elfcpp::R_386_TLS_LDM_PUSH:
1757 case elfcpp::R_386_TLS_LDM_CALL:
1758 case elfcpp::R_386_TLS_LDM_POP:
1759 case elfcpp::R_386_USED_BY_INTEL_200:
1761 // Not expected. We will give an error later.
1766 // Report an unsupported relocation against a local symbol.
1769 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1770 unsigned int r_type)
1772 gold_error(_("%s: unsupported reloc %u against local symbol"),
1773 object->name().c_str(), r_type);
1776 // Return whether we need to make a PLT entry for a relocation of a
1777 // given type against a STT_GNU_IFUNC symbol.
1780 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1781 Sized_relobj_file<32, false>* object,
1782 unsigned int r_type)
1784 int flags = Scan::get_reference_flags(r_type);
1785 if (flags & Symbol::TLS_REF)
1786 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1787 object->name().c_str(), r_type);
1791 // Scan a relocation for a local symbol.
1794 Target_i386::Scan::local(Symbol_table* symtab,
1796 Target_i386* target,
1797 Sized_relobj_file<32, false>* object,
1798 unsigned int data_shndx,
1799 Output_section* output_section,
1800 const elfcpp::Rel<32, false>& reloc,
1801 unsigned int r_type,
1802 const elfcpp::Sym<32, false>& lsym,
1808 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1809 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1810 && this->reloc_needs_plt_for_ifunc(object, r_type))
1812 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1813 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1818 case elfcpp::R_386_NONE:
1819 case elfcpp::R_386_GNU_VTINHERIT:
1820 case elfcpp::R_386_GNU_VTENTRY:
1823 case elfcpp::R_386_32:
1824 // If building a shared library (or a position-independent
1825 // executable), we need to create a dynamic relocation for
1826 // this location. The relocation applied at link time will
1827 // apply the link-time value, so we flag the location with
1828 // an R_386_RELATIVE relocation so the dynamic loader can
1829 // relocate it easily.
1830 if (parameters->options().output_is_position_independent())
1832 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1833 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1834 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1835 output_section, data_shndx,
1836 reloc.get_r_offset());
1840 case elfcpp::R_386_16:
1841 case elfcpp::R_386_8:
1842 // If building a shared library (or a position-independent
1843 // executable), we need to create a dynamic relocation for
1844 // this location. Because the addend needs to remain in the
1845 // data section, we need to be careful not to apply this
1846 // relocation statically.
1847 if (parameters->options().output_is_position_independent())
1849 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1850 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1851 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1852 rel_dyn->add_local(object, r_sym, r_type, output_section,
1853 data_shndx, reloc.get_r_offset());
1856 gold_assert(lsym.get_st_value() == 0);
1857 unsigned int shndx = lsym.get_st_shndx();
1859 shndx = object->adjust_sym_shndx(r_sym, shndx,
1862 object->error(_("section symbol %u has bad shndx %u"),
1865 rel_dyn->add_local_section(object, shndx,
1866 r_type, output_section,
1867 data_shndx, reloc.get_r_offset());
1872 case elfcpp::R_386_PC32:
1873 case elfcpp::R_386_PC16:
1874 case elfcpp::R_386_PC8:
1877 case elfcpp::R_386_PLT32:
1878 // Since we know this is a local symbol, we can handle this as a
1882 case elfcpp::R_386_GOTOFF:
1883 case elfcpp::R_386_GOTPC:
1884 // We need a GOT section.
1885 target->got_section(symtab, layout);
1888 case elfcpp::R_386_GOT32:
1889 case elfcpp::R_386_GOT32X:
1891 // We need GOT section.
1892 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1894 // If the relocation symbol isn't IFUNC,
1895 // and is local, then we will convert
1896 // mov foo@GOT(%reg), %reg
1898 // lea foo@GOTOFF(%reg), %reg
1899 // in Relocate::relocate.
1900 if (reloc.get_r_offset() >= 2
1901 && lsym.get_st_type() != elfcpp::STT_GNU_IFUNC)
1903 section_size_type stype;
1904 const unsigned char* view = object->section_contents(data_shndx,
1906 if (view[reloc.get_r_offset() - 2] == 0x8b)
1910 // Otherwise, the symbol requires a GOT entry.
1911 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1913 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1914 // lets function pointers compare correctly with shared
1915 // libraries. Otherwise we would need an IRELATIVE reloc.
1917 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1918 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1920 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1923 // If we are generating a shared object, we need to add a
1924 // dynamic RELATIVE relocation for this symbol's GOT entry.
1925 if (parameters->options().output_is_position_independent())
1927 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1928 unsigned int got_offset =
1929 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1930 rel_dyn->add_local_relative(object, r_sym,
1931 elfcpp::R_386_RELATIVE,
1938 // These are relocations which should only be seen by the
1939 // dynamic linker, and should never be seen here.
1940 case elfcpp::R_386_COPY:
1941 case elfcpp::R_386_GLOB_DAT:
1942 case elfcpp::R_386_JUMP_SLOT:
1943 case elfcpp::R_386_RELATIVE:
1944 case elfcpp::R_386_IRELATIVE:
1945 case elfcpp::R_386_TLS_TPOFF:
1946 case elfcpp::R_386_TLS_DTPMOD32:
1947 case elfcpp::R_386_TLS_DTPOFF32:
1948 case elfcpp::R_386_TLS_TPOFF32:
1949 case elfcpp::R_386_TLS_DESC:
1950 gold_error(_("%s: unexpected reloc %u in object file"),
1951 object->name().c_str(), r_type);
1954 // These are initial TLS relocs, which are expected when
1956 case elfcpp::R_386_TLS_GD: // Global-dynamic
1957 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1958 case elfcpp::R_386_TLS_DESC_CALL:
1959 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1960 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1961 case elfcpp::R_386_TLS_IE: // Initial-exec
1962 case elfcpp::R_386_TLS_IE_32:
1963 case elfcpp::R_386_TLS_GOTIE:
1964 case elfcpp::R_386_TLS_LE: // Local-exec
1965 case elfcpp::R_386_TLS_LE_32:
1967 bool output_is_shared = parameters->options().shared();
1968 const tls::Tls_optimization optimized_type
1969 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1972 case elfcpp::R_386_TLS_GD: // Global-dynamic
1973 if (optimized_type == tls::TLSOPT_NONE)
1975 // Create a pair of GOT entries for the module index and
1976 // dtv-relative offset.
1977 Output_data_got<32, false>* got
1978 = target->got_section(symtab, layout);
1979 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1980 unsigned int shndx = lsym.get_st_shndx();
1982 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1984 object->error(_("local symbol %u has bad shndx %u"),
1987 got->add_local_pair_with_rel(object, r_sym, shndx,
1989 target->rel_dyn_section(layout),
1990 elfcpp::R_386_TLS_DTPMOD32);
1992 else if (optimized_type != tls::TLSOPT_TO_LE)
1993 unsupported_reloc_local(object, r_type);
1996 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1997 target->define_tls_base_symbol(symtab, layout);
1998 if (optimized_type == tls::TLSOPT_NONE)
2000 // Create a double GOT entry with an R_386_TLS_DESC
2001 // reloc. The R_386_TLS_DESC reloc is resolved
2002 // lazily, so the GOT entry needs to be in an area in
2003 // .got.plt, not .got. Call got_section to make sure
2004 // the section has been created.
2005 target->got_section(symtab, layout);
2006 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2007 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2008 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2010 unsigned int got_offset = got->add_constant(0);
2011 // The local symbol value is stored in the second
2013 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
2014 // That set the GOT offset of the local symbol to
2015 // point to the second entry, but we want it to
2016 // point to the first.
2017 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2019 Reloc_section* rt = target->rel_tls_desc_section(layout);
2020 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
2023 else if (optimized_type != tls::TLSOPT_TO_LE)
2024 unsupported_reloc_local(object, r_type);
2027 case elfcpp::R_386_TLS_DESC_CALL:
2030 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2031 if (optimized_type == tls::TLSOPT_NONE)
2033 // Create a GOT entry for the module index.
2034 target->got_mod_index_entry(symtab, layout, object);
2036 else if (optimized_type != tls::TLSOPT_TO_LE)
2037 unsupported_reloc_local(object, r_type);
2040 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2043 case elfcpp::R_386_TLS_IE: // Initial-exec
2044 case elfcpp::R_386_TLS_IE_32:
2045 case elfcpp::R_386_TLS_GOTIE:
2046 layout->set_has_static_tls();
2047 if (optimized_type == tls::TLSOPT_NONE)
2049 // For the R_386_TLS_IE relocation, we need to create a
2050 // dynamic relocation when building a shared library.
2051 if (r_type == elfcpp::R_386_TLS_IE
2052 && parameters->options().shared())
2054 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2056 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2057 rel_dyn->add_local_relative(object, r_sym,
2058 elfcpp::R_386_RELATIVE,
2059 output_section, data_shndx,
2060 reloc.get_r_offset());
2062 // Create a GOT entry for the tp-relative offset.
2063 Output_data_got<32, false>* got
2064 = target->got_section(symtab, layout);
2065 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2066 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2067 ? elfcpp::R_386_TLS_TPOFF32
2068 : elfcpp::R_386_TLS_TPOFF);
2069 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2070 ? GOT_TYPE_TLS_OFFSET
2071 : GOT_TYPE_TLS_NOFFSET);
2072 got->add_local_with_rel(object, r_sym, got_type,
2073 target->rel_dyn_section(layout),
2076 else if (optimized_type != tls::TLSOPT_TO_LE)
2077 unsupported_reloc_local(object, r_type);
2080 case elfcpp::R_386_TLS_LE: // Local-exec
2081 case elfcpp::R_386_TLS_LE_32:
2082 layout->set_has_static_tls();
2083 if (output_is_shared)
2085 // We need to create a dynamic relocation.
2086 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2087 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2088 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2089 ? elfcpp::R_386_TLS_TPOFF32
2090 : elfcpp::R_386_TLS_TPOFF);
2091 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2092 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
2093 data_shndx, reloc.get_r_offset());
2103 case elfcpp::R_386_32PLT:
2104 case elfcpp::R_386_TLS_GD_32:
2105 case elfcpp::R_386_TLS_GD_PUSH:
2106 case elfcpp::R_386_TLS_GD_CALL:
2107 case elfcpp::R_386_TLS_GD_POP:
2108 case elfcpp::R_386_TLS_LDM_32:
2109 case elfcpp::R_386_TLS_LDM_PUSH:
2110 case elfcpp::R_386_TLS_LDM_CALL:
2111 case elfcpp::R_386_TLS_LDM_POP:
2112 case elfcpp::R_386_USED_BY_INTEL_200:
2114 unsupported_reloc_local(object, r_type);
2119 // Report an unsupported relocation against a global symbol.
2122 Target_i386::Scan::unsupported_reloc_global(
2123 Sized_relobj_file<32, false>* object,
2124 unsigned int r_type,
2127 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2128 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2132 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
2136 case elfcpp::R_386_32:
2137 case elfcpp::R_386_16:
2138 case elfcpp::R_386_8:
2139 case elfcpp::R_386_GOTOFF:
2140 case elfcpp::R_386_GOT32:
2141 case elfcpp::R_386_GOT32X:
2152 Target_i386::Scan::local_reloc_may_be_function_pointer(
2156 Sized_relobj_file<32, false>* ,
2159 const elfcpp::Rel<32, false>& ,
2160 unsigned int r_type,
2161 const elfcpp::Sym<32, false>&)
2163 return possible_function_pointer_reloc(r_type);
2167 Target_i386::Scan::global_reloc_may_be_function_pointer(
2171 Sized_relobj_file<32, false>* ,
2174 const elfcpp::Rel<32, false>& ,
2175 unsigned int r_type,
2178 return possible_function_pointer_reloc(r_type);
2181 // Scan a relocation for a global symbol.
2184 Target_i386::Scan::global(Symbol_table* symtab,
2186 Target_i386* target,
2187 Sized_relobj_file<32, false>* object,
2188 unsigned int data_shndx,
2189 Output_section* output_section,
2190 const elfcpp::Rel<32, false>& reloc,
2191 unsigned int r_type,
2194 // A STT_GNU_IFUNC symbol may require a PLT entry.
2195 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2196 && this->reloc_needs_plt_for_ifunc(object, r_type))
2197 target->make_plt_entry(symtab, layout, gsym);
2201 case elfcpp::R_386_NONE:
2202 case elfcpp::R_386_GNU_VTINHERIT:
2203 case elfcpp::R_386_GNU_VTENTRY:
2206 case elfcpp::R_386_32:
2207 case elfcpp::R_386_16:
2208 case elfcpp::R_386_8:
2210 // Make a PLT entry if necessary.
2211 if (gsym->needs_plt_entry())
2213 target->make_plt_entry(symtab, layout, gsym);
2214 // Since this is not a PC-relative relocation, we may be
2215 // taking the address of a function. In that case we need to
2216 // set the entry in the dynamic symbol table to the address of
2218 if (gsym->is_from_dynobj() && !parameters->options().shared())
2219 gsym->set_needs_dynsym_value();
2221 // Make a dynamic relocation if necessary.
2222 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2224 if (!parameters->options().output_is_position_independent()
2225 && gsym->may_need_copy_reloc())
2227 target->copy_reloc(symtab, layout, object,
2228 data_shndx, output_section, gsym, reloc);
2230 else if (r_type == elfcpp::R_386_32
2231 && gsym->type() == elfcpp::STT_GNU_IFUNC
2232 && gsym->can_use_relative_reloc(false)
2233 && !gsym->is_from_dynobj()
2234 && !gsym->is_undefined()
2235 && !gsym->is_preemptible())
2237 // Use an IRELATIVE reloc for a locally defined
2238 // STT_GNU_IFUNC symbol. This makes a function
2239 // address in a PIE executable match the address in a
2240 // shared library that it links against.
2241 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
2242 rel_dyn->add_symbolless_global_addend(gsym,
2243 elfcpp::R_386_IRELATIVE,
2246 reloc.get_r_offset());
2248 else if (r_type == elfcpp::R_386_32
2249 && gsym->can_use_relative_reloc(false))
2251 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2252 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2253 output_section, object,
2254 data_shndx, reloc.get_r_offset());
2258 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2259 rel_dyn->add_global(gsym, r_type, output_section, object,
2260 data_shndx, reloc.get_r_offset());
2266 case elfcpp::R_386_PC32:
2267 case elfcpp::R_386_PC16:
2268 case elfcpp::R_386_PC8:
2270 // Make a PLT entry if necessary.
2271 if (gsym->needs_plt_entry())
2273 // These relocations are used for function calls only in
2274 // non-PIC code. For a 32-bit relocation in a shared library,
2275 // we'll need a text relocation anyway, so we can skip the
2276 // PLT entry and let the dynamic linker bind the call directly
2277 // to the target. For smaller relocations, we should use a
2278 // PLT entry to ensure that the call can reach.
2279 if (!parameters->options().shared()
2280 || r_type != elfcpp::R_386_PC32)
2281 target->make_plt_entry(symtab, layout, gsym);
2283 // Make a dynamic relocation if necessary.
2284 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2286 if (parameters->options().output_is_executable()
2287 && gsym->may_need_copy_reloc())
2289 target->copy_reloc(symtab, layout, object,
2290 data_shndx, output_section, gsym, reloc);
2294 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2295 rel_dyn->add_global(gsym, r_type, output_section, object,
2296 data_shndx, reloc.get_r_offset());
2302 case elfcpp::R_386_GOT32:
2303 case elfcpp::R_386_GOT32X:
2305 // The symbol requires a GOT section.
2306 Output_data_got<32, false>* got = target->got_section(symtab, layout);
2308 // If we convert this from
2309 // mov foo@GOT(%reg), %reg
2311 // lea foo@GOTOFF(%reg), %reg
2312 // in Relocate::relocate, then there is nothing to do here.
2313 if (reloc.get_r_offset() >= 2
2314 && Target_i386::can_convert_mov_to_lea(gsym))
2316 section_size_type stype;
2317 const unsigned char* view = object->section_contents(data_shndx,
2319 if (view[reloc.get_r_offset() - 2] == 0x8b)
2323 if (gsym->final_value_is_known())
2325 // For a STT_GNU_IFUNC symbol we want the PLT address.
2326 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2327 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2329 got->add_global(gsym, GOT_TYPE_STANDARD);
2333 // If this symbol is not fully resolved, we need to add a
2334 // GOT entry with a dynamic relocation.
2335 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2337 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2339 // 1) The symbol may be defined in some other module.
2341 // 2) We are building a shared library and this is a
2342 // protected symbol; using GLOB_DAT means that the dynamic
2343 // linker can use the address of the PLT in the main
2344 // executable when appropriate so that function address
2345 // comparisons work.
2347 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2348 // code, again so that function address comparisons work.
2349 if (gsym->is_from_dynobj()
2350 || gsym->is_undefined()
2351 || gsym->is_preemptible()
2352 || (gsym->visibility() == elfcpp::STV_PROTECTED
2353 && parameters->options().shared())
2354 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2355 && parameters->options().output_is_position_independent()))
2356 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2357 rel_dyn, elfcpp::R_386_GLOB_DAT);
2360 // For a STT_GNU_IFUNC symbol we want to write the PLT
2361 // offset into the GOT, so that function pointer
2362 // comparisons work correctly.
2364 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2365 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2368 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2369 // Tell the dynamic linker to use the PLT address
2370 // when resolving relocations.
2371 if (gsym->is_from_dynobj()
2372 && !parameters->options().shared())
2373 gsym->set_needs_dynsym_value();
2377 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2378 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2386 case elfcpp::R_386_PLT32:
2387 // If the symbol is fully resolved, this is just a PC32 reloc.
2388 // Otherwise we need a PLT entry.
2389 if (gsym->final_value_is_known())
2391 // If building a shared library, we can also skip the PLT entry
2392 // if the symbol is defined in the output file and is protected
2394 if (gsym->is_defined()
2395 && !gsym->is_from_dynobj()
2396 && !gsym->is_preemptible())
2398 target->make_plt_entry(symtab, layout, gsym);
2401 case elfcpp::R_386_GOTOFF:
2402 // A GOT-relative reference must resolve locally.
2403 if (!gsym->is_defined())
2404 gold_error(_("%s: relocation R_386_GOTOFF against undefined symbol %s"
2405 " cannot be used when making a shared object"),
2406 object->name().c_str(), gsym->name());
2407 else if (gsym->is_from_dynobj())
2408 gold_error(_("%s: relocation R_386_GOTOFF against external symbol %s"
2409 " cannot be used when making a shared object"),
2410 object->name().c_str(), gsym->name());
2411 else if (gsym->is_preemptible())
2412 gold_error(_("%s: relocation R_386_GOTOFF against preemptible symbol %s"
2413 " cannot be used when making a shared object"),
2414 object->name().c_str(), gsym->name());
2415 // We need a GOT section.
2416 target->got_section(symtab, layout);
2419 case elfcpp::R_386_GOTPC:
2420 // We need a GOT section.
2421 target->got_section(symtab, layout);
2424 // These are relocations which should only be seen by the
2425 // dynamic linker, and should never be seen here.
2426 case elfcpp::R_386_COPY:
2427 case elfcpp::R_386_GLOB_DAT:
2428 case elfcpp::R_386_JUMP_SLOT:
2429 case elfcpp::R_386_RELATIVE:
2430 case elfcpp::R_386_IRELATIVE:
2431 case elfcpp::R_386_TLS_TPOFF:
2432 case elfcpp::R_386_TLS_DTPMOD32:
2433 case elfcpp::R_386_TLS_DTPOFF32:
2434 case elfcpp::R_386_TLS_TPOFF32:
2435 case elfcpp::R_386_TLS_DESC:
2436 gold_error(_("%s: unexpected reloc %u in object file"),
2437 object->name().c_str(), r_type);
2440 // These are initial tls relocs, which are expected when
2442 case elfcpp::R_386_TLS_GD: // Global-dynamic
2443 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2444 case elfcpp::R_386_TLS_DESC_CALL:
2445 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2446 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2447 case elfcpp::R_386_TLS_IE: // Initial-exec
2448 case elfcpp::R_386_TLS_IE_32:
2449 case elfcpp::R_386_TLS_GOTIE:
2450 case elfcpp::R_386_TLS_LE: // Local-exec
2451 case elfcpp::R_386_TLS_LE_32:
2453 const bool is_final = gsym->final_value_is_known();
2454 const tls::Tls_optimization optimized_type
2455 = Target_i386::optimize_tls_reloc(is_final, r_type);
2458 case elfcpp::R_386_TLS_GD: // Global-dynamic
2459 if (optimized_type == tls::TLSOPT_NONE)
2461 // Create a pair of GOT entries for the module index and
2462 // dtv-relative offset.
2463 Output_data_got<32, false>* got
2464 = target->got_section(symtab, layout);
2465 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2466 target->rel_dyn_section(layout),
2467 elfcpp::R_386_TLS_DTPMOD32,
2468 elfcpp::R_386_TLS_DTPOFF32);
2470 else if (optimized_type == tls::TLSOPT_TO_IE)
2472 // Create a GOT entry for the tp-relative offset.
2473 Output_data_got<32, false>* got
2474 = target->got_section(symtab, layout);
2475 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2476 target->rel_dyn_section(layout),
2477 elfcpp::R_386_TLS_TPOFF);
2479 else if (optimized_type != tls::TLSOPT_TO_LE)
2480 unsupported_reloc_global(object, r_type, gsym);
2483 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
2484 target->define_tls_base_symbol(symtab, layout);
2485 if (optimized_type == tls::TLSOPT_NONE)
2487 // Create a double GOT entry with an R_386_TLS_DESC
2488 // reloc. The R_386_TLS_DESC reloc is resolved
2489 // lazily, so the GOT entry needs to be in an area in
2490 // .got.plt, not .got. Call got_section to make sure
2491 // the section has been created.
2492 target->got_section(symtab, layout);
2493 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2494 Reloc_section* rt = target->rel_tls_desc_section(layout);
2495 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2496 elfcpp::R_386_TLS_DESC, 0);
2498 else if (optimized_type == tls::TLSOPT_TO_IE)
2500 // Create a GOT entry for the tp-relative offset.
2501 Output_data_got<32, false>* got
2502 = target->got_section(symtab, layout);
2503 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2504 target->rel_dyn_section(layout),
2505 elfcpp::R_386_TLS_TPOFF);
2507 else if (optimized_type != tls::TLSOPT_TO_LE)
2508 unsupported_reloc_global(object, r_type, gsym);
2511 case elfcpp::R_386_TLS_DESC_CALL:
2514 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2515 if (optimized_type == tls::TLSOPT_NONE)
2517 // Create a GOT entry for the module index.
2518 target->got_mod_index_entry(symtab, layout, object);
2520 else if (optimized_type != tls::TLSOPT_TO_LE)
2521 unsupported_reloc_global(object, r_type, gsym);
2524 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2527 case elfcpp::R_386_TLS_IE: // Initial-exec
2528 case elfcpp::R_386_TLS_IE_32:
2529 case elfcpp::R_386_TLS_GOTIE:
2530 layout->set_has_static_tls();
2531 if (optimized_type == tls::TLSOPT_NONE)
2533 // For the R_386_TLS_IE relocation, we need to create a
2534 // dynamic relocation when building a shared library.
2535 if (r_type == elfcpp::R_386_TLS_IE
2536 && parameters->options().shared())
2538 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2539 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2540 output_section, object,
2542 reloc.get_r_offset());
2544 // Create a GOT entry for the tp-relative offset.
2545 Output_data_got<32, false>* got
2546 = target->got_section(symtab, layout);
2547 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2548 ? elfcpp::R_386_TLS_TPOFF32
2549 : elfcpp::R_386_TLS_TPOFF);
2550 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2551 ? GOT_TYPE_TLS_OFFSET
2552 : GOT_TYPE_TLS_NOFFSET);
2553 got->add_global_with_rel(gsym, got_type,
2554 target->rel_dyn_section(layout),
2557 else if (optimized_type != tls::TLSOPT_TO_LE)
2558 unsupported_reloc_global(object, r_type, gsym);
2561 case elfcpp::R_386_TLS_LE: // Local-exec
2562 case elfcpp::R_386_TLS_LE_32:
2563 layout->set_has_static_tls();
2564 if (parameters->options().shared())
2566 // We need to create a dynamic relocation.
2567 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2568 ? elfcpp::R_386_TLS_TPOFF32
2569 : elfcpp::R_386_TLS_TPOFF);
2570 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2571 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2572 data_shndx, reloc.get_r_offset());
2582 case elfcpp::R_386_32PLT:
2583 case elfcpp::R_386_TLS_GD_32:
2584 case elfcpp::R_386_TLS_GD_PUSH:
2585 case elfcpp::R_386_TLS_GD_CALL:
2586 case elfcpp::R_386_TLS_GD_POP:
2587 case elfcpp::R_386_TLS_LDM_32:
2588 case elfcpp::R_386_TLS_LDM_PUSH:
2589 case elfcpp::R_386_TLS_LDM_CALL:
2590 case elfcpp::R_386_TLS_LDM_POP:
2591 case elfcpp::R_386_USED_BY_INTEL_200:
2593 unsupported_reloc_global(object, r_type, gsym);
2598 // Process relocations for gc.
2601 Target_i386::gc_process_relocs(Symbol_table* symtab,
2603 Sized_relobj_file<32, false>* object,
2604 unsigned int data_shndx,
2606 const unsigned char* prelocs,
2608 Output_section* output_section,
2609 bool needs_special_offset_handling,
2610 size_t local_symbol_count,
2611 const unsigned char* plocal_symbols)
2613 gold::gc_process_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2622 needs_special_offset_handling,
2627 // Scan relocations for a section.
2630 Target_i386::scan_relocs(Symbol_table* symtab,
2632 Sized_relobj_file<32, false>* object,
2633 unsigned int data_shndx,
2634 unsigned int sh_type,
2635 const unsigned char* prelocs,
2637 Output_section* output_section,
2638 bool needs_special_offset_handling,
2639 size_t local_symbol_count,
2640 const unsigned char* plocal_symbols)
2642 if (sh_type == elfcpp::SHT_RELA)
2644 gold_error(_("%s: unsupported RELA reloc section"),
2645 object->name().c_str());
2649 gold::scan_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2658 needs_special_offset_handling,
2663 // Finalize the sections.
2666 Target_i386::do_finalize_sections(
2668 const Input_objects*,
2669 Symbol_table* symtab)
2671 const Reloc_section* rel_plt = (this->plt_ == NULL
2673 : this->plt_->rel_plt());
2674 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2675 this->rel_dyn_, true, false);
2677 // Emit any relocs we saved in an attempt to avoid generating COPY
2679 if (this->copy_relocs_.any_saved_relocs())
2680 this->copy_relocs_.emit(this->rel_dyn_section(layout));
2682 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2683 // the .got.plt section.
2684 Symbol* sym = this->global_offset_table_;
2687 uint32_t data_size = this->got_plt_->current_data_size();
2688 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2691 if (parameters->doing_static_link()
2692 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2694 // If linking statically, make sure that the __rel_iplt symbols
2695 // were defined if necessary, even if we didn't create a PLT.
2696 static const Define_symbol_in_segment syms[] =
2699 "__rel_iplt_start", // name
2700 elfcpp::PT_LOAD, // segment_type
2701 elfcpp::PF_W, // segment_flags_set
2702 elfcpp::PF(0), // segment_flags_clear
2705 elfcpp::STT_NOTYPE, // type
2706 elfcpp::STB_GLOBAL, // binding
2707 elfcpp::STV_HIDDEN, // visibility
2709 Symbol::SEGMENT_START, // offset_from_base
2713 "__rel_iplt_end", // name
2714 elfcpp::PT_LOAD, // segment_type
2715 elfcpp::PF_W, // segment_flags_set
2716 elfcpp::PF(0), // segment_flags_clear
2719 elfcpp::STT_NOTYPE, // type
2720 elfcpp::STB_GLOBAL, // binding
2721 elfcpp::STV_HIDDEN, // visibility
2723 Symbol::SEGMENT_START, // offset_from_base
2728 symtab->define_symbols(layout, 2, syms,
2729 layout->script_options()->saw_sections_clause());
2733 // Return whether a direct absolute static relocation needs to be applied.
2734 // In cases where Scan::local() or Scan::global() has created
2735 // a dynamic relocation other than R_386_RELATIVE, the addend
2736 // of the relocation is carried in the data, and we must not
2737 // apply the static relocation.
2740 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2741 unsigned int r_type,
2743 Output_section* output_section)
2745 // If the output section is not allocated, then we didn't call
2746 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2748 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2751 int ref_flags = Scan::get_reference_flags(r_type);
2753 // For local symbols, we will have created a non-RELATIVE dynamic
2754 // relocation only if (a) the output is position independent,
2755 // (b) the relocation is absolute (not pc- or segment-relative), and
2756 // (c) the relocation is not 32 bits wide.
2758 return !(parameters->options().output_is_position_independent()
2759 && (ref_flags & Symbol::ABSOLUTE_REF)
2762 // For global symbols, we use the same helper routines used in the
2763 // scan pass. If we did not create a dynamic relocation, or if we
2764 // created a RELATIVE dynamic relocation, we should apply the static
2766 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2767 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2768 && gsym->can_use_relative_reloc(ref_flags
2769 & Symbol::FUNCTION_CALL);
2770 return !has_dyn || is_rel;
2773 // Perform a relocation.
2776 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2778 Target_i386* target,
2779 Output_section* output_section,
2781 const unsigned char* preloc,
2782 const Sized_symbol<32>* gsym,
2783 const Symbol_value<32>* psymval,
2784 unsigned char* view,
2785 elfcpp::Elf_types<32>::Elf_Addr address,
2786 section_size_type view_size)
2788 const elfcpp::Rel<32, false> rel(preloc);
2789 unsigned int r_type = elfcpp::elf_r_type<32>(rel.get_r_info());
2791 if (this->skip_call_tls_get_addr_)
2793 if ((r_type != elfcpp::R_386_PLT32
2794 && r_type != elfcpp::R_386_GOT32X
2795 && r_type != elfcpp::R_386_PC32)
2797 || strcmp(gsym->name(), "___tls_get_addr") != 0)
2799 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2800 _("missing expected TLS relocation"));
2801 this->skip_call_tls_get_addr_ = false;
2805 this->skip_call_tls_get_addr_ = false;
2813 const Sized_relobj_file<32, false>* object = relinfo->object;
2815 // Pick the value to use for symbols defined in shared objects.
2816 Symbol_value<32> symval;
2818 && gsym->type() == elfcpp::STT_GNU_IFUNC
2819 && r_type == elfcpp::R_386_32
2820 && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2821 && gsym->can_use_relative_reloc(false)
2822 && !gsym->is_from_dynobj()
2823 && !gsym->is_undefined()
2824 && !gsym->is_preemptible())
2826 // In this case we are generating a R_386_IRELATIVE reloc. We
2827 // want to use the real value of the symbol, not the PLT offset.
2829 else if (gsym != NULL
2830 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2832 symval.set_output_value(target->plt_address_for_global(gsym));
2835 else if (gsym == NULL && psymval->is_ifunc_symbol())
2837 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2838 if (object->local_has_plt_offset(r_sym))
2840 symval.set_output_value(target->plt_address_for_local(object, r_sym));
2849 case elfcpp::R_386_NONE:
2850 case elfcpp::R_386_GNU_VTINHERIT:
2851 case elfcpp::R_386_GNU_VTENTRY:
2854 case elfcpp::R_386_32:
2855 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2856 Relocate_functions<32, false>::rel32(view, object, psymval);
2859 case elfcpp::R_386_PC32:
2860 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2861 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2864 case elfcpp::R_386_16:
2865 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2866 Relocate_functions<32, false>::rel16(view, object, psymval);
2869 case elfcpp::R_386_PC16:
2870 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2871 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2874 case elfcpp::R_386_8:
2875 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2876 Relocate_functions<32, false>::rel8(view, object, psymval);
2879 case elfcpp::R_386_PC8:
2880 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2881 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2884 case elfcpp::R_386_PLT32:
2885 gold_assert(gsym == NULL
2886 || gsym->has_plt_offset()
2887 || gsym->final_value_is_known()
2888 || (gsym->is_defined()
2889 && !gsym->is_from_dynobj()
2890 && !gsym->is_preemptible()));
2891 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2894 case elfcpp::R_386_GOT32:
2895 case elfcpp::R_386_GOT32X:
2896 baseless = (view[-1] & 0xc7) == 0x5;
2897 // R_386_GOT32 and R_386_GOT32X don't work without base register
2898 // when generating a position-independent output file.
2900 && parameters->options().output_is_position_independent())
2903 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2904 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2905 r_type, gsym->demangled_name().c_str());
2907 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2908 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2913 // mov foo@GOT(%reg), %reg
2915 // lea foo@GOTOFF(%reg), %reg
2917 if (rel.get_r_offset() >= 2
2919 && ((gsym == NULL && !psymval->is_ifunc_symbol())
2921 && Target_i386::can_convert_mov_to_lea(gsym))))
2924 elfcpp::Elf_types<32>::Elf_Addr value;
2925 value = psymval->value(object, 0);
2926 // Don't subtract the .got.plt section address for baseless
2929 value -= target->got_plt_section()->address();
2930 Relocate_functions<32, false>::rel32(view, value);
2934 // The GOT pointer points to the end of the GOT section.
2935 // We need to subtract the size of the GOT section to get
2936 // the actual offset to use in the relocation.
2937 unsigned int got_offset = 0;
2940 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2941 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2942 - target->got_size());
2946 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2947 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2948 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2949 - target->got_size());
2951 // Add the .got.plt section address for baseless addressing.
2953 got_offset += target->got_plt_section()->address();
2954 Relocate_functions<32, false>::rel32(view, got_offset);
2958 case elfcpp::R_386_GOTOFF:
2960 elfcpp::Elf_types<32>::Elf_Addr reladdr;
2961 reladdr = target->got_plt_section()->address();
2962 Relocate_functions<32, false>::pcrel32(view, object, psymval, reladdr);
2966 case elfcpp::R_386_GOTPC:
2968 elfcpp::Elf_types<32>::Elf_Addr value;
2969 value = target->got_plt_section()->address();
2970 Relocate_functions<32, false>::pcrel32(view, value, address);
2974 case elfcpp::R_386_COPY:
2975 case elfcpp::R_386_GLOB_DAT:
2976 case elfcpp::R_386_JUMP_SLOT:
2977 case elfcpp::R_386_RELATIVE:
2978 case elfcpp::R_386_IRELATIVE:
2979 // These are outstanding tls relocs, which are unexpected when
2981 case elfcpp::R_386_TLS_TPOFF:
2982 case elfcpp::R_386_TLS_DTPMOD32:
2983 case elfcpp::R_386_TLS_DTPOFF32:
2984 case elfcpp::R_386_TLS_TPOFF32:
2985 case elfcpp::R_386_TLS_DESC:
2986 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2987 _("unexpected reloc %u in object file"),
2991 // These are initial tls relocs, which are expected when
2993 case elfcpp::R_386_TLS_GD: // Global-dynamic
2994 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2995 case elfcpp::R_386_TLS_DESC_CALL:
2996 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2997 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2998 case elfcpp::R_386_TLS_IE: // Initial-exec
2999 case elfcpp::R_386_TLS_IE_32:
3000 case elfcpp::R_386_TLS_GOTIE:
3001 case elfcpp::R_386_TLS_LE: // Local-exec
3002 case elfcpp::R_386_TLS_LE_32:
3003 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
3004 view, address, view_size);
3007 case elfcpp::R_386_32PLT:
3008 case elfcpp::R_386_TLS_GD_32:
3009 case elfcpp::R_386_TLS_GD_PUSH:
3010 case elfcpp::R_386_TLS_GD_CALL:
3011 case elfcpp::R_386_TLS_GD_POP:
3012 case elfcpp::R_386_TLS_LDM_32:
3013 case elfcpp::R_386_TLS_LDM_PUSH:
3014 case elfcpp::R_386_TLS_LDM_CALL:
3015 case elfcpp::R_386_TLS_LDM_POP:
3016 case elfcpp::R_386_USED_BY_INTEL_200:
3018 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3019 _("unsupported reloc %u"),
3027 // Perform a TLS relocation.
3030 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
3031 Target_i386* target,
3033 const elfcpp::Rel<32, false>& rel,
3034 unsigned int r_type,
3035 const Sized_symbol<32>* gsym,
3036 const Symbol_value<32>* psymval,
3037 unsigned char* view,
3038 elfcpp::Elf_types<32>::Elf_Addr,
3039 section_size_type view_size)
3041 Output_segment* tls_segment = relinfo->layout->tls_segment();
3043 const Sized_relobj_file<32, false>* object = relinfo->object;
3045 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
3047 const bool is_final = (gsym == NULL
3048 ? !parameters->options().shared()
3049 : gsym->final_value_is_known());
3050 const tls::Tls_optimization optimized_type
3051 = Target_i386::optimize_tls_reloc(is_final, r_type);
3054 case elfcpp::R_386_TLS_GD: // Global-dynamic
3055 if (optimized_type == tls::TLSOPT_TO_LE)
3057 if (tls_segment == NULL)
3059 gold_assert(parameters->errors()->error_count() > 0
3060 || issue_undefined_symbol_error(gsym));
3063 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3064 rel, r_type, value, view,
3070 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3071 ? GOT_TYPE_TLS_NOFFSET
3072 : GOT_TYPE_TLS_PAIR);
3073 unsigned int got_offset;
3076 gold_assert(gsym->has_got_offset(got_type));
3077 got_offset = gsym->got_offset(got_type) - target->got_size();
3081 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3082 gold_assert(object->local_has_got_offset(r_sym, got_type));
3083 got_offset = (object->local_got_offset(r_sym, got_type)
3084 - target->got_size());
3086 if (optimized_type == tls::TLSOPT_TO_IE)
3088 this->tls_gd_to_ie(relinfo, relnum, rel, r_type,
3089 got_offset, view, view_size);
3092 else if (optimized_type == tls::TLSOPT_NONE)
3094 // Relocate the field with the offset of the pair of GOT
3096 Relocate_functions<32, false>::rel32(view, got_offset);
3100 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3101 _("unsupported reloc %u"),
3105 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3106 case elfcpp::R_386_TLS_DESC_CALL:
3107 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3108 if (optimized_type == tls::TLSOPT_TO_LE)
3110 if (tls_segment == NULL)
3112 gold_assert(parameters->errors()->error_count() > 0
3113 || issue_undefined_symbol_error(gsym));
3116 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3117 rel, r_type, value, view,
3123 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3124 ? GOT_TYPE_TLS_NOFFSET
3125 : GOT_TYPE_TLS_DESC);
3126 unsigned int got_offset = 0;
3127 if (r_type == elfcpp::R_386_TLS_GOTDESC
3128 && optimized_type == tls::TLSOPT_NONE)
3130 // We created GOT entries in the .got.tlsdesc portion of
3131 // the .got.plt section, but the offset stored in the
3132 // symbol is the offset within .got.tlsdesc.
3133 got_offset = (target->got_size()
3134 + target->got_plt_section()->data_size());
3138 gold_assert(gsym->has_got_offset(got_type));
3139 got_offset += gsym->got_offset(got_type) - target->got_size();
3143 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3144 gold_assert(object->local_has_got_offset(r_sym, got_type));
3145 got_offset += (object->local_got_offset(r_sym, got_type)
3146 - target->got_size());
3148 if (optimized_type == tls::TLSOPT_TO_IE)
3150 this->tls_desc_gd_to_ie(relinfo, relnum, rel, r_type,
3151 got_offset, view, view_size);
3154 else if (optimized_type == tls::TLSOPT_NONE)
3156 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3158 // Relocate the field with the offset of the pair of GOT
3160 Relocate_functions<32, false>::rel32(view, got_offset);
3165 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3166 _("unsupported reloc %u"),
3170 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3171 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
3173 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3174 _("both SUN and GNU model "
3175 "TLS relocations"));
3178 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3179 if (optimized_type == tls::TLSOPT_TO_LE)
3181 if (tls_segment == NULL)
3183 gold_assert(parameters->errors()->error_count() > 0
3184 || issue_undefined_symbol_error(gsym));
3187 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
3188 value, view, view_size);
3191 else if (optimized_type == tls::TLSOPT_NONE)
3193 // Relocate the field with the offset of the GOT entry for
3194 // the module index.
3195 unsigned int got_offset;
3196 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3197 - target->got_size());
3198 Relocate_functions<32, false>::rel32(view, got_offset);
3201 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3202 _("unsupported reloc %u"),
3206 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3207 if (optimized_type == tls::TLSOPT_TO_LE)
3209 // This reloc can appear in debugging sections, in which
3210 // case we must not convert to local-exec. We decide what
3211 // to do based on whether the section is marked as
3212 // containing executable code. That is what the GNU linker
3214 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
3215 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
3217 if (tls_segment == NULL)
3219 gold_assert(parameters->errors()->error_count() > 0
3220 || issue_undefined_symbol_error(gsym));
3223 value -= tls_segment->memsz();
3226 Relocate_functions<32, false>::rel32(view, value);
3229 case elfcpp::R_386_TLS_IE: // Initial-exec
3230 case elfcpp::R_386_TLS_GOTIE:
3231 case elfcpp::R_386_TLS_IE_32:
3232 if (optimized_type == tls::TLSOPT_TO_LE)
3234 if (tls_segment == NULL)
3236 gold_assert(parameters->errors()->error_count() > 0
3237 || issue_undefined_symbol_error(gsym));
3240 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3241 rel, r_type, value, view,
3245 else if (optimized_type == tls::TLSOPT_NONE)
3247 // Relocate the field with the offset of the GOT entry for
3248 // the tp-relative offset of the symbol.
3249 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
3250 ? GOT_TYPE_TLS_OFFSET
3251 : GOT_TYPE_TLS_NOFFSET);
3252 unsigned int got_offset;
3255 gold_assert(gsym->has_got_offset(got_type));
3256 got_offset = gsym->got_offset(got_type);
3260 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3261 gold_assert(object->local_has_got_offset(r_sym, got_type));
3262 got_offset = object->local_got_offset(r_sym, got_type);
3264 // For the R_386_TLS_IE relocation, we need to apply the
3265 // absolute address of the GOT entry.
3266 if (r_type == elfcpp::R_386_TLS_IE)
3267 got_offset += target->got_plt_section()->address();
3268 // All GOT offsets are relative to the end of the GOT.
3269 got_offset -= target->got_size();
3270 Relocate_functions<32, false>::rel32(view, got_offset);
3273 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3274 _("unsupported reloc %u"),
3278 case elfcpp::R_386_TLS_LE: // Local-exec
3279 // If we're creating a shared library, a dynamic relocation will
3280 // have been created for this location, so do not apply it now.
3281 if (!parameters->options().shared())
3283 if (tls_segment == NULL)
3285 gold_assert(parameters->errors()->error_count() > 0
3286 || issue_undefined_symbol_error(gsym));
3289 value -= tls_segment->memsz();
3290 Relocate_functions<32, false>::rel32(view, value);
3294 case elfcpp::R_386_TLS_LE_32:
3295 // If we're creating a shared library, a dynamic relocation will
3296 // have been created for this location, so do not apply it now.
3297 if (!parameters->options().shared())
3299 if (tls_segment == NULL)
3301 gold_assert(parameters->errors()->error_count() > 0
3302 || issue_undefined_symbol_error(gsym));
3305 value = tls_segment->memsz() - value;
3306 Relocate_functions<32, false>::rel32(view, value);
3312 // Do a relocation in which we convert a TLS General-Dynamic to a
3316 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
3318 Output_segment* tls_segment,
3319 const elfcpp::Rel<32, false>& rel,
3321 elfcpp::Elf_types<32>::Elf_Addr value,
3322 unsigned char* view,
3323 section_size_type view_size)
3325 // leal foo(,%ebx,1),%eax; call ___tls_get_addr@PLT
3326 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3327 // leal foo(%ebx),%eax; call ___tls_get_addr@PLT
3328 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3329 // leal foo(%reg),%eax; call *___tls_get_addr@GOT(%reg)
3330 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3332 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3333 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3335 unsigned char op1 = view[-1];
3336 unsigned char op2 = view[-2];
3337 unsigned char op3 = view[4];
3339 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3340 op2 == 0x8d || op2 == 0x04);
3341 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3342 op3 == 0xe8 || op3 == 0xff);
3348 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3349 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3350 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3351 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3352 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3356 unsigned char reg = op1 & 7;
3357 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3358 ((op1 & 0xf8) == 0x80
3361 && (op3 == 0xe8 || (view[5] & 0x7) == reg)));
3363 || (rel.get_r_offset() + 9 < view_size
3364 && view[9] == 0x90))
3366 // There is an indirect call or a trailing nop. Use the size
3368 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3373 // Use the five byte subl.
3374 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3378 value = tls_segment->memsz() - value;
3379 Relocate_functions<32, false>::rel32(view + roff, value);
3381 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3383 this->skip_call_tls_get_addr_ = true;
3386 // Do a relocation in which we convert a TLS General-Dynamic to an
3390 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3392 const elfcpp::Rel<32, false>& rel,
3394 elfcpp::Elf_types<32>::Elf_Addr value,
3395 unsigned char* view,
3396 section_size_type view_size)
3398 // leal foo(,%ebx,1),%eax; call ___tls_get_addr@PLT
3399 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3400 // leal foo(%ebx),%eax; call ___tls_get_addr@PLT; nop
3401 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3402 // leal foo(%reg),%eax; call *___tls_get_addr@GOT(%reg)
3403 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%reg),%eax
3405 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3406 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3408 unsigned char op1 = view[-1];
3409 unsigned char op2 = view[-2];
3410 unsigned char op3 = view[4];
3412 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3413 op2 == 0x8d || op2 == 0x04);
3414 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3415 op3 == 0xe8 || op3 == 0xff);
3421 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3422 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3423 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3424 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3429 unsigned char reg = op1 & 7;
3430 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
3431 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3432 ((op1 & 0xf8) == 0x80
3435 && ((op3 == 0xe8 && view[9] == 0x90)
3436 || (view[5] & 0x7) == reg)));
3440 memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3441 Relocate_functions<32, false>::rel32(view + roff, value);
3443 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3445 this->skip_call_tls_get_addr_ = true;
3448 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3449 // General-Dynamic to a Local-Exec.
3452 Target_i386::Relocate::tls_desc_gd_to_le(
3453 const Relocate_info<32, false>* relinfo,
3455 Output_segment* tls_segment,
3456 const elfcpp::Rel<32, false>& rel,
3457 unsigned int r_type,
3458 elfcpp::Elf_types<32>::Elf_Addr value,
3459 unsigned char* view,
3460 section_size_type view_size)
3462 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3464 // leal foo@TLSDESC(%ebx), %eax
3465 // ==> leal foo@NTPOFF, %eax
3466 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3467 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3468 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3469 view[-2] == 0x8d && view[-1] == 0x83);
3471 value -= tls_segment->memsz();
3472 Relocate_functions<32, false>::rel32(view, value);
3476 // call *foo@TLSCALL(%eax)
3478 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3479 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3480 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3481 view[0] == 0xff && view[1] == 0x10);
3487 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3488 // General-Dynamic to an Initial-Exec.
3491 Target_i386::Relocate::tls_desc_gd_to_ie(
3492 const Relocate_info<32, false>* relinfo,
3494 const elfcpp::Rel<32, false>& rel,
3495 unsigned int r_type,
3496 elfcpp::Elf_types<32>::Elf_Addr value,
3497 unsigned char* view,
3498 section_size_type view_size)
3500 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3502 // leal foo@TLSDESC(%ebx), %eax
3503 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3504 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3505 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3506 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3507 view[-2] == 0x8d && view[-1] == 0x83);
3509 Relocate_functions<32, false>::rel32(view, value);
3513 // call *foo@TLSCALL(%eax)
3515 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3516 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3517 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3518 view[0] == 0xff && view[1] == 0x10);
3524 // Do a relocation in which we convert a TLS Local-Dynamic to a
3528 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3531 const elfcpp::Rel<32, false>& rel,
3533 elfcpp::Elf_types<32>::Elf_Addr,
3534 unsigned char* view,
3535 section_size_type view_size)
3537 // leal foo(%ebx), %eax; call ___tls_get_addr@PLT
3538 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3539 // leal foo(%reg), %eax; call call *___tls_get_addr@GOT(%reg)
3540 // ==> movl %gs:0,%eax; leal (%esi),%esi
3542 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3544 unsigned char op1 = view[-1];
3545 unsigned char op2 = view[-2];
3546 unsigned char op3 = view[4];
3548 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3549 op3 == 0xe8 || op3 == 0xff);
3550 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size,
3551 op3 == 0xe8 ? 9 : 10);
3553 // FIXME: Does this test really always pass?
3554 tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x8d);
3556 unsigned char reg = op1 & 7;
3557 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3558 ((op1 & 0xf8) == 0x80
3561 && (op3 == 0xe8 || (view[5] & 0x7) == reg)));
3564 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3566 memcpy(view - 2, "\x65\xa1\0\0\0\0\x8d\xb6\0\0\0\0", 12);
3568 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3570 this->skip_call_tls_get_addr_ = true;
3573 // Do a relocation in which we convert a TLS Initial-Exec to a
3577 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3579 Output_segment* tls_segment,
3580 const elfcpp::Rel<32, false>& rel,
3581 unsigned int r_type,
3582 elfcpp::Elf_types<32>::Elf_Addr value,
3583 unsigned char* view,
3584 section_size_type view_size)
3586 // We have to actually change the instructions, which means that we
3587 // need to examine the opcodes to figure out which instruction we
3589 if (r_type == elfcpp::R_386_TLS_IE)
3591 // movl %gs:XX,%eax ==> movl $YY,%eax
3592 // movl %gs:XX,%reg ==> movl $YY,%reg
3593 // addl %gs:XX,%reg ==> addl $YY,%reg
3594 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3595 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3597 unsigned char op1 = view[-1];
3600 // movl XX,%eax ==> movl $YY,%eax
3605 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3607 unsigned char op2 = view[-2];
3610 // movl XX,%reg ==> movl $YY,%reg
3611 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3612 (op1 & 0xc7) == 0x05);
3614 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3616 else if (op2 == 0x03)
3618 // addl XX,%reg ==> addl $YY,%reg
3619 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3620 (op1 & 0xc7) == 0x05);
3622 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3625 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3630 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3631 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3632 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3633 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3634 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3636 unsigned char op1 = view[-1];
3637 unsigned char op2 = view[-2];
3638 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3639 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3642 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3644 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3646 else if (op2 == 0x2b)
3648 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3650 view[-1] = 0xe8 | ((op1 >> 3) & 7);
3652 else if (op2 == 0x03)
3654 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3656 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3659 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3662 value = tls_segment->memsz() - value;
3663 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3666 Relocate_functions<32, false>::rel32(view, value);
3669 // Relocate section data.
3672 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3673 unsigned int sh_type,
3674 const unsigned char* prelocs,
3676 Output_section* output_section,
3677 bool needs_special_offset_handling,
3678 unsigned char* view,
3679 elfcpp::Elf_types<32>::Elf_Addr address,
3680 section_size_type view_size,
3681 const Reloc_symbol_changes* reloc_symbol_changes)
3683 gold_assert(sh_type == elfcpp::SHT_REL);
3685 gold::relocate_section<32, false, Target_i386, Relocate,
3686 gold::Default_comdat_behavior, Classify_reloc>(
3692 needs_special_offset_handling,
3696 reloc_symbol_changes);
3699 // Return the size of a relocation while scanning during a relocatable
3703 Target_i386::Classify_reloc::get_size_for_reloc(
3704 unsigned int r_type,
3709 case elfcpp::R_386_NONE:
3710 case elfcpp::R_386_GNU_VTINHERIT:
3711 case elfcpp::R_386_GNU_VTENTRY:
3712 case elfcpp::R_386_TLS_GD: // Global-dynamic
3713 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3714 case elfcpp::R_386_TLS_DESC_CALL:
3715 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3716 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3717 case elfcpp::R_386_TLS_IE: // Initial-exec
3718 case elfcpp::R_386_TLS_IE_32:
3719 case elfcpp::R_386_TLS_GOTIE:
3720 case elfcpp::R_386_TLS_LE: // Local-exec
3721 case elfcpp::R_386_TLS_LE_32:
3724 case elfcpp::R_386_32:
3725 case elfcpp::R_386_PC32:
3726 case elfcpp::R_386_GOT32:
3727 case elfcpp::R_386_GOT32X:
3728 case elfcpp::R_386_PLT32:
3729 case elfcpp::R_386_GOTOFF:
3730 case elfcpp::R_386_GOTPC:
3733 case elfcpp::R_386_16:
3734 case elfcpp::R_386_PC16:
3737 case elfcpp::R_386_8:
3738 case elfcpp::R_386_PC8:
3741 // These are relocations which should only be seen by the
3742 // dynamic linker, and should never be seen here.
3743 case elfcpp::R_386_COPY:
3744 case elfcpp::R_386_GLOB_DAT:
3745 case elfcpp::R_386_JUMP_SLOT:
3746 case elfcpp::R_386_RELATIVE:
3747 case elfcpp::R_386_IRELATIVE:
3748 case elfcpp::R_386_TLS_TPOFF:
3749 case elfcpp::R_386_TLS_DTPMOD32:
3750 case elfcpp::R_386_TLS_DTPOFF32:
3751 case elfcpp::R_386_TLS_TPOFF32:
3752 case elfcpp::R_386_TLS_DESC:
3753 object->error(_("unexpected reloc %u in object file"), r_type);
3756 case elfcpp::R_386_32PLT:
3757 case elfcpp::R_386_TLS_GD_32:
3758 case elfcpp::R_386_TLS_GD_PUSH:
3759 case elfcpp::R_386_TLS_GD_CALL:
3760 case elfcpp::R_386_TLS_GD_POP:
3761 case elfcpp::R_386_TLS_LDM_32:
3762 case elfcpp::R_386_TLS_LDM_PUSH:
3763 case elfcpp::R_386_TLS_LDM_CALL:
3764 case elfcpp::R_386_TLS_LDM_POP:
3765 case elfcpp::R_386_USED_BY_INTEL_200:
3767 object->error(_("unsupported reloc %u in object file"), r_type);
3772 // Scan the relocs during a relocatable link.
3775 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3777 Sized_relobj_file<32, false>* object,
3778 unsigned int data_shndx,
3779 unsigned int sh_type,
3780 const unsigned char* prelocs,
3782 Output_section* output_section,
3783 bool needs_special_offset_handling,
3784 size_t local_symbol_count,
3785 const unsigned char* plocal_symbols,
3786 Relocatable_relocs* rr)
3788 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
3789 Scan_relocatable_relocs;
3791 gold_assert(sh_type == elfcpp::SHT_REL);
3793 gold::scan_relocatable_relocs<32, false, Scan_relocatable_relocs>(
3801 needs_special_offset_handling,
3807 // Scan the relocs for --emit-relocs.
3810 Target_i386::emit_relocs_scan(Symbol_table* symtab,
3812 Sized_relobj_file<32, false>* object,
3813 unsigned int data_shndx,
3814 unsigned int sh_type,
3815 const unsigned char* prelocs,
3817 Output_section* output_section,
3818 bool needs_special_offset_handling,
3819 size_t local_symbol_count,
3820 const unsigned char* plocal_syms,
3821 Relocatable_relocs* rr)
3823 typedef gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
3825 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
3826 Emit_relocs_strategy;
3828 gold_assert(sh_type == elfcpp::SHT_REL);
3830 gold::scan_relocatable_relocs<32, false, Emit_relocs_strategy>(
3838 needs_special_offset_handling,
3844 // Emit relocations for a section.
3847 Target_i386::relocate_relocs(
3848 const Relocate_info<32, false>* relinfo,
3849 unsigned int sh_type,
3850 const unsigned char* prelocs,
3852 Output_section* output_section,
3853 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
3854 unsigned char* view,
3855 elfcpp::Elf_types<32>::Elf_Addr view_address,
3856 section_size_type view_size,
3857 unsigned char* reloc_view,
3858 section_size_type reloc_view_size)
3860 gold_assert(sh_type == elfcpp::SHT_REL);
3862 gold::relocate_relocs<32, false, Classify_reloc>(
3867 offset_in_output_section,
3875 // Return the value to use for a dynamic which requires special
3876 // treatment. This is how we support equality comparisons of function
3877 // pointers across shared library boundaries, as described in the
3878 // processor specific ABI supplement.
3881 Target_i386::do_dynsym_value(const Symbol* gsym) const
3883 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3884 return this->plt_address_for_global(gsym);
3887 // Return a string used to fill a code section with nops to take up
3888 // the specified length.
3891 Target_i386::do_code_fill(section_size_type length) const
3895 // Build a jmp instruction to skip over the bytes.
3896 unsigned char jmp[5];
3898 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3899 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3900 + std::string(length - 5, static_cast<char>(0x90)));
3903 // Nop sequences of various lengths.
3904 const char nop1[1] = { '\x90' }; // nop
3905 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
3906 const char nop3[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3907 const char nop4[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3909 const char nop5[5] = { '\x90', '\x8d', '\x74', // nop
3910 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3911 const char nop6[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3912 '\x00', '\x00', '\x00' };
3913 const char nop7[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3914 '\x00', '\x00', '\x00',
3916 const char nop8[8] = { '\x90', '\x8d', '\xb4', // nop
3917 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3919 const char nop9[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3920 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3921 '\x00', '\x00', '\x00' };
3922 const char nop10[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3923 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3924 '\x00', '\x00', '\x00',
3926 const char nop11[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3927 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3928 '\x27', '\x00', '\x00',
3930 const char nop12[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3931 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3932 '\x8d', '\xbf', '\x00',
3933 '\x00', '\x00', '\x00' };
3934 const char nop13[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3935 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3936 '\x8d', '\xbc', '\x27',
3937 '\x00', '\x00', '\x00',
3939 const char nop14[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3940 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3941 '\x00', '\x8d', '\xbc',
3942 '\x27', '\x00', '\x00',
3944 const char nop15[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3945 '\x90', '\x90', '\x90', // nop,nop,nop,...
3946 '\x90', '\x90', '\x90',
3947 '\x90', '\x90', '\x90',
3948 '\x90', '\x90', '\x90' };
3950 const char* nops[16] = {
3952 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3953 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3956 return std::string(nops[length], length);
3959 // Return the value to use for the base of a DW_EH_PE_datarel offset
3960 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3961 // assembler can not write out the difference between two labels in
3962 // different sections, so instead of using a pc-relative value they
3963 // use an offset from the GOT.
3966 Target_i386::do_ehframe_datarel_base() const
3968 gold_assert(this->global_offset_table_ != NULL);
3969 Symbol* sym = this->global_offset_table_;
3970 Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3971 return ssym->value();
3974 // Return whether SYM should be treated as a call to a non-split
3975 // function. We don't want that to be true of a call to a
3976 // get_pc_thunk function.
3979 Target_i386::do_is_call_to_non_split(const Symbol* sym,
3980 const unsigned char*,
3981 const unsigned char*,
3982 section_size_type) const
3984 return (sym->type() == elfcpp::STT_FUNC
3985 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3988 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3989 // compiled with -fsplit-stack. The function calls non-split-stack
3990 // code. We have to change the function so that it always ensures
3991 // that it has enough stack space to run some random function.
3994 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3995 section_offset_type fnoffset,
3996 section_size_type fnsize,
3997 const unsigned char*,
3999 unsigned char* view,
4000 section_size_type view_size,
4002 std::string* to) const
4004 // The function starts with a comparison of the stack pointer and a
4005 // field in the TCB. This is followed by a jump.
4008 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
4011 // We will call __morestack if the carry flag is set after this
4012 // comparison. We turn the comparison into an stc instruction
4014 view[fnoffset] = '\xf9';
4015 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
4017 // lea NN(%esp),%ecx
4018 // lea NN(%esp),%edx
4019 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
4020 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
4023 // This is loading an offset from the stack pointer for a
4024 // comparison. The offset is negative, so we decrease the
4025 // offset by the amount of space we need for the stack. This
4026 // means we will avoid calling __morestack if there happens to
4027 // be plenty of space on the stack already.
4028 unsigned char* pval = view + fnoffset + 3;
4029 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4030 val -= parameters->options().split_stack_adjust_size();
4031 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4035 if (!object->has_no_split_stack())
4036 object->error(_("failed to match split-stack sequence at "
4037 "section %u offset %0zx"),
4038 shndx, static_cast<size_t>(fnoffset));
4042 // We have to change the function so that it calls
4043 // __morestack_non_split instead of __morestack. The former will
4044 // allocate additional stack space.
4045 *from = "__morestack";
4046 *to = "__morestack_non_split";
4049 // The selector for i386 object files. Note this is never instantiated
4050 // directly. It's only used in Target_selector_i386_nacl, below.
4052 class Target_selector_i386 : public Target_selector_freebsd
4055 Target_selector_i386()
4056 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
4057 "elf32-i386", "elf32-i386-freebsd",
4062 do_instantiate_target()
4063 { return new Target_i386(); }
4066 // NaCl variant. It uses different PLT contents.
4068 class Output_data_plt_i386_nacl : public Output_data_plt_i386
4071 Output_data_plt_i386_nacl(Layout* layout,
4072 Output_data_got_plt_i386* got_plt,
4073 Output_data_space* got_irelative)
4074 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
4078 virtual unsigned int
4079 do_get_plt_entry_size() const
4080 { return plt_entry_size; }
4083 do_add_eh_frame(Layout* layout)
4085 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
4086 plt_eh_frame_fde, plt_eh_frame_fde_size);
4089 // The size of an entry in the PLT.
4090 static const int plt_entry_size = 64;
4092 // The .eh_frame unwind information for the PLT.
4093 static const int plt_eh_frame_fde_size = 32;
4094 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4097 class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
4100 Output_data_plt_i386_nacl_exec(Layout* layout,
4101 Output_data_got_plt_i386* got_plt,
4102 Output_data_space* got_irelative)
4103 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4108 do_fill_first_plt_entry(unsigned char* pov,
4109 elfcpp::Elf_types<32>::Elf_Addr got_address);
4111 virtual unsigned int
4112 do_fill_plt_entry(unsigned char* pov,
4113 elfcpp::Elf_types<32>::Elf_Addr got_address,
4114 unsigned int got_offset,
4115 unsigned int plt_offset,
4116 unsigned int plt_rel_offset);
4119 // The first entry in the PLT for an executable.
4120 static const unsigned char first_plt_entry[plt_entry_size];
4122 // Other entries in the PLT for an executable.
4123 static const unsigned char plt_entry[plt_entry_size];
4126 class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
4129 Output_data_plt_i386_nacl_dyn(Layout* layout,
4130 Output_data_got_plt_i386* got_plt,
4131 Output_data_space* got_irelative)
4132 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4137 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
4139 virtual unsigned int
4140 do_fill_plt_entry(unsigned char* pov,
4141 elfcpp::Elf_types<32>::Elf_Addr,
4142 unsigned int got_offset,
4143 unsigned int plt_offset,
4144 unsigned int plt_rel_offset);
4147 // The first entry in the PLT for a shared object.
4148 static const unsigned char first_plt_entry[plt_entry_size];
4150 // Other entries in the PLT for a shared object.
4151 static const unsigned char plt_entry[plt_entry_size];
4154 class Target_i386_nacl : public Target_i386
4158 : Target_i386(&i386_nacl_info)
4162 virtual Output_data_plt_i386*
4163 do_make_data_plt(Layout* layout,
4164 Output_data_got_plt_i386* got_plt,
4165 Output_data_space* got_irelative,
4169 return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
4171 return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
4175 do_code_fill(section_size_type length) const;
4178 static const Target::Target_info i386_nacl_info;
4181 const Target::Target_info Target_i386_nacl::i386_nacl_info =
4184 false, // is_big_endian
4185 elfcpp::EM_386, // machine_code
4186 false, // has_make_symbol
4187 false, // has_resolve
4188 true, // has_code_fill
4189 true, // is_default_stack_executable
4190 true, // can_icf_inline_merge_sections
4192 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4193 0x20000, // default_text_segment_address
4194 0x10000, // abi_pagesize (overridable by -z max-page-size)
4195 0x10000, // common_pagesize (overridable by -z common-page-size)
4196 true, // isolate_execinstr
4197 0x10000000, // rosegment_gap
4198 elfcpp::SHN_UNDEF, // small_common_shndx
4199 elfcpp::SHN_UNDEF, // large_common_shndx
4200 0, // small_common_section_flags
4201 0, // large_common_section_flags
4202 NULL, // attributes_section
4203 NULL, // attributes_vendor
4204 "_start", // entry_symbol_name
4205 32, // hash_entry_size
4206 elfcpp::SHT_PROGBITS, // unwind_section_type
4209 #define NACLMASK 0xe0 // 32-byte alignment mask
4212 Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
4214 0xff, 0x35, // pushl contents of memory address
4215 0, 0, 0, 0, // replaced with address of .got + 4
4216 0x8b, 0x0d, // movl contents of address, %ecx
4217 0, 0, 0, 0, // replaced with address of .got + 8
4218 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4219 0xff, 0xe1, // jmp *%ecx
4220 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4221 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4222 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4223 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4224 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4225 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4226 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4227 0x90, 0x90, 0x90, 0x90, 0x90
4231 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4233 elfcpp::Elf_types<32>::Elf_Addr got_address)
4235 memcpy(pov, first_plt_entry, plt_entry_size);
4236 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
4237 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
4240 // The first entry in the PLT for a shared object.
4243 Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
4245 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4246 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4247 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4248 0xff, 0xe1, // jmp *%ecx
4249 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4250 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4251 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4252 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4253 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4254 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4255 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4256 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4257 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4258 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4262 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4264 elfcpp::Elf_types<32>::Elf_Addr)
4266 memcpy(pov, first_plt_entry, plt_entry_size);
4269 // Subsequent entries in the PLT for an executable.
4272 Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
4274 0x8b, 0x0d, // movl contents of address, %ecx */
4275 0, 0, 0, 0, // replaced with address of symbol in .got
4276 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4277 0xff, 0xe1, // jmp *%ecx
4279 // Pad to the next 32-byte boundary with nop instructions.
4281 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4282 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4284 // Lazy GOT entries point here (32-byte aligned).
4285 0x68, // pushl immediate
4286 0, 0, 0, 0, // replaced with offset into relocation table
4287 0xe9, // jmp relative
4288 0, 0, 0, 0, // replaced with offset to start of .plt
4290 // Pad to the next 32-byte boundary with nop instructions.
4291 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4292 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4297 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4299 elfcpp::Elf_types<32>::Elf_Addr got_address,
4300 unsigned int got_offset,
4301 unsigned int plt_offset,
4302 unsigned int plt_rel_offset)
4304 memcpy(pov, plt_entry, plt_entry_size);
4305 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4306 got_address + got_offset);
4307 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4308 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4312 // Subsequent entries in the PLT for a shared object.
4315 Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
4317 0x8b, 0x8b, // movl offset(%ebx), %ecx
4318 0, 0, 0, 0, // replaced with offset of symbol in .got
4319 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4320 0xff, 0xe1, // jmp *%ecx
4322 // Pad to the next 32-byte boundary with nop instructions.
4324 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4325 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4327 // Lazy GOT entries point here (32-byte aligned).
4328 0x68, // pushl immediate
4329 0, 0, 0, 0, // replaced with offset into relocation table.
4330 0xe9, // jmp relative
4331 0, 0, 0, 0, // replaced with offset to start of .plt.
4333 // Pad to the next 32-byte boundary with nop instructions.
4334 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4335 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4340 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4342 elfcpp::Elf_types<32>::Elf_Addr,
4343 unsigned int got_offset,
4344 unsigned int plt_offset,
4345 unsigned int plt_rel_offset)
4347 memcpy(pov, plt_entry, plt_entry_size);
4348 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
4349 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4350 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4355 Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4357 0, 0, 0, 0, // Replaced with offset to .plt.
4358 0, 0, 0, 0, // Replaced with size of .plt.
4359 0, // Augmentation size.
4360 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
4361 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4362 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
4363 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4364 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4365 13, // Block length.
4366 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
4367 elfcpp::DW_OP_breg8, 0, // Push %eip.
4368 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4369 elfcpp::DW_OP_and, // & (%eip & 0x3f).
4370 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4371 elfcpp::DW_OP_ge, // >= ((%eip & 0x3f) >= 0x25)
4372 elfcpp::DW_OP_lit2, // Push 2.
4373 elfcpp::DW_OP_shl, // << (((%eip & 0x3f) >= 0x25) << 2)
4374 elfcpp::DW_OP_plus, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4375 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4379 // Return a string used to fill a code section with nops.
4380 // For NaCl, long NOPs are only valid if they do not cross
4381 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4383 Target_i386_nacl::do_code_fill(section_size_type length) const
4385 return std::string(length, static_cast<char>(0x90));
4388 // The selector for i386-nacl object files.
4390 class Target_selector_i386_nacl
4391 : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
4394 Target_selector_i386_nacl()
4395 : Target_selector_nacl<Target_selector_i386,
4396 Target_i386_nacl>("x86-32",
4402 Target_selector_i386_nacl target_selector_i386;
4404 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4406 class Target_iamcu : public Target_i386
4410 : Target_i386(&iamcu_info)
4414 // Information about this specific target which we pass to the
4415 // general Target structure.
4416 static const Target::Target_info iamcu_info;
4419 const Target::Target_info Target_iamcu::iamcu_info =
4422 false, // is_big_endian
4423 elfcpp::EM_IAMCU, // machine_code
4424 false, // has_make_symbol
4425 false, // has_resolve
4426 true, // has_code_fill
4427 true, // is_default_stack_executable
4428 true, // can_icf_inline_merge_sections
4430 "/usr/lib/libc.so.1", // dynamic_linker
4431 0x08048000, // default_text_segment_address
4432 0x1000, // abi_pagesize (overridable by -z max-page-size)
4433 0x1000, // common_pagesize (overridable by -z common-page-size)
4434 false, // isolate_execinstr
4436 elfcpp::SHN_UNDEF, // small_common_shndx
4437 elfcpp::SHN_UNDEF, // large_common_shndx
4438 0, // small_common_section_flags
4439 0, // large_common_section_flags
4440 NULL, // attributes_section
4441 NULL, // attributes_vendor
4442 "_start", // entry_symbol_name
4443 32, // hash_entry_size
4444 elfcpp::SHT_PROGBITS, // unwind_section_type
4447 class Target_selector_iamcu : public Target_selector
4450 Target_selector_iamcu()
4451 : Target_selector(elfcpp::EM_IAMCU, 32, false, "elf32-iamcu",
4456 do_instantiate_target()
4457 { return new Target_iamcu(); }
4460 Target_selector_iamcu target_selector_iamcu;
4462 } // End anonymous namespace.