1 // i386.cc -- i386 target support for gold.
3 // Copyright (C) 2006-2016 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*) const;
505 // Adjust -fsplit-stack code which calls non-split-stack code.
507 do_calls_non_split(Relobj* object, unsigned int shndx,
508 section_offset_type fnoffset, section_size_type fnsize,
509 const unsigned char* prelocs, size_t reloc_count,
510 unsigned char* view, section_size_type view_size,
511 std::string* from, std::string* to) const;
513 // Return the size of the GOT section.
517 gold_assert(this->got_ != NULL);
518 return this->got_->data_size();
521 // Return the number of entries in the GOT.
523 got_entry_count() const
525 if (this->got_ == NULL)
527 return this->got_size() / 4;
530 // Return the number of entries in the PLT.
532 plt_entry_count() const;
534 // Return the offset of the first non-reserved PLT entry.
536 first_plt_entry_offset() const;
538 // Return the size of each PLT entry.
540 plt_entry_size() const;
543 // Instantiate the plt_ member.
544 // This chooses the right PLT flavor for an executable or a shared object.
545 Output_data_plt_i386*
546 make_data_plt(Layout* layout,
547 Output_data_got_plt_i386* got_plt,
548 Output_data_space* got_irelative,
550 { return this->do_make_data_plt(layout, got_plt, got_irelative, dyn); }
552 virtual Output_data_plt_i386*
553 do_make_data_plt(Layout* layout,
554 Output_data_got_plt_i386* got_plt,
555 Output_data_space* got_irelative,
559 return new Output_data_plt_i386_dyn(layout, got_plt, got_irelative);
561 return new Output_data_plt_i386_exec(layout, got_plt, got_irelative);
565 // The class which scans relocations.
570 get_reference_flags(unsigned int r_type);
573 local(Symbol_table* symtab, Layout* layout, Target_i386* target,
574 Sized_relobj_file<32, false>* object,
575 unsigned int data_shndx,
576 Output_section* output_section,
577 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
578 const elfcpp::Sym<32, false>& lsym,
582 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
583 Sized_relobj_file<32, false>* object,
584 unsigned int data_shndx,
585 Output_section* output_section,
586 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
590 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
592 Sized_relobj_file<32, false>* object,
593 unsigned int data_shndx,
594 Output_section* output_section,
595 const elfcpp::Rel<32, false>& reloc,
597 const elfcpp::Sym<32, false>& lsym);
600 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
602 Sized_relobj_file<32, false>* object,
603 unsigned int data_shndx,
604 Output_section* output_section,
605 const elfcpp::Rel<32, false>& reloc,
610 possible_function_pointer_reloc(unsigned int r_type);
613 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
614 unsigned int r_type);
617 unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
620 unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
624 // The class which implements relocation.
629 : skip_call_tls_get_addr_(false),
630 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
635 if (this->skip_call_tls_get_addr_)
637 // FIXME: This needs to specify the location somehow.
638 gold_error(_("missing expected TLS relocation"));
642 // Return whether the static relocation needs to be applied.
644 should_apply_static_reloc(const Sized_symbol<32>* gsym,
647 Output_section* output_section);
649 // Do a relocation. Return false if the caller should not issue
650 // any warnings about this relocation.
652 relocate(const Relocate_info<32, false>*, unsigned int,
653 Target_i386*, Output_section*, size_t, const unsigned char*,
654 const Sized_symbol<32>*, const Symbol_value<32>*,
655 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
659 // Do a TLS relocation.
661 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
662 size_t relnum, const elfcpp::Rel<32, false>&,
663 unsigned int r_type, const Sized_symbol<32>*,
664 const Symbol_value<32>*,
665 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
668 // Do a TLS General-Dynamic to Initial-Exec transition.
670 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
671 Output_segment* tls_segment,
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 Output_segment* tls_segment,
691 const elfcpp::Rel<32, false>&, unsigned int r_type,
692 elfcpp::Elf_types<32>::Elf_Addr value,
694 section_size_type view_size);
696 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
699 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
700 Output_segment* tls_segment,
701 const elfcpp::Rel<32, false>&, unsigned int r_type,
702 elfcpp::Elf_types<32>::Elf_Addr value,
704 section_size_type view_size);
706 // Do a TLS Local-Dynamic to Local-Exec transition.
708 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
709 Output_segment* tls_segment,
710 const elfcpp::Rel<32, false>&, unsigned int r_type,
711 elfcpp::Elf_types<32>::Elf_Addr value,
713 section_size_type view_size);
715 // Do a TLS Initial-Exec to Local-Exec transition.
717 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
718 Output_segment* tls_segment,
719 const elfcpp::Rel<32, false>&, unsigned int r_type,
720 elfcpp::Elf_types<32>::Elf_Addr value,
722 section_size_type view_size);
724 // We need to keep track of which type of local dynamic relocation
725 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
726 enum Local_dynamic_type
733 // This is set if we should skip the next reloc, which should be a
734 // PLT32 reloc against ___tls_get_addr.
735 bool skip_call_tls_get_addr_;
736 // The type of local dynamic relocation we have seen in the section
737 // being relocated, if any.
738 Local_dynamic_type local_dynamic_type_;
741 // A class for inquiring about properties of a relocation,
742 // used while scanning relocs during a relocatable link and
743 // garbage collection.
744 class Classify_reloc :
745 public gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
748 // Return the size of the addend of the relocation (only used for SHT_REL).
750 get_size_for_reloc(unsigned int, Relobj*);
753 // Adjust TLS relocation type based on the options and whether this
754 // is a local symbol.
755 static tls::Tls_optimization
756 optimize_tls_reloc(bool is_final, int r_type);
758 // Check if relocation against this symbol is a candidate for
760 // mov foo@GOT(%reg), %reg
762 // lea foo@GOTOFF(%reg), %reg.
764 can_convert_mov_to_lea(const Symbol* gsym)
766 gold_assert(gsym != NULL);
767 return (gsym->type() != elfcpp::STT_GNU_IFUNC
768 && !gsym->is_undefined ()
769 && !gsym->is_from_dynobj()
770 && !gsym->is_preemptible()
771 && (!parameters->options().shared()
772 || (gsym->visibility() != elfcpp::STV_DEFAULT
773 && gsym->visibility() != elfcpp::STV_PROTECTED)
774 || parameters->options().Bsymbolic())
775 && strcmp(gsym->name(), "_DYNAMIC") != 0);
778 // Get the GOT section, creating it if necessary.
779 Output_data_got<32, false>*
780 got_section(Symbol_table*, Layout*);
782 // Get the GOT PLT section.
783 Output_data_got_plt_i386*
784 got_plt_section() const
786 gold_assert(this->got_plt_ != NULL);
787 return this->got_plt_;
790 // Get the GOT section for TLSDESC entries.
791 Output_data_got<32, false>*
792 got_tlsdesc_section() const
794 gold_assert(this->got_tlsdesc_ != NULL);
795 return this->got_tlsdesc_;
798 // Create the PLT section.
800 make_plt_section(Symbol_table* symtab, Layout* layout);
802 // Create a PLT entry for a global symbol.
804 make_plt_entry(Symbol_table*, Layout*, Symbol*);
806 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
808 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
809 Sized_relobj_file<32, false>* relobj,
810 unsigned int local_sym_index);
812 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
814 define_tls_base_symbol(Symbol_table*, Layout*);
816 // Create a GOT entry for the TLS module index.
818 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
819 Sized_relobj_file<32, false>* object);
821 // Get the PLT section.
822 Output_data_plt_i386*
825 gold_assert(this->plt_ != NULL);
829 // Get the dynamic reloc section, creating it if necessary.
831 rel_dyn_section(Layout*);
833 // Get the section to use for TLS_DESC relocations.
835 rel_tls_desc_section(Layout*) const;
837 // Get the section to use for IRELATIVE relocations.
839 rel_irelative_section(Layout*);
841 // Add a potential copy relocation.
843 copy_reloc(Symbol_table* symtab, Layout* layout,
844 Sized_relobj_file<32, false>* object,
845 unsigned int shndx, Output_section* output_section,
846 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
848 unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
849 this->copy_relocs_.copy_reloc(symtab, layout,
850 symtab->get_sized_symbol<32>(sym),
851 object, shndx, output_section,
852 r_type, reloc.get_r_offset(), 0,
853 this->rel_dyn_section(layout));
856 // Information about this specific target which we pass to the
857 // general Target structure.
858 static const Target::Target_info i386_info;
860 // The types of GOT entries needed for this platform.
861 // These values are exposed to the ABI in an incremental link.
862 // Do not renumber existing values without changing the version
863 // number of the .gnu_incremental_inputs section.
866 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
867 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
868 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
869 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
870 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
874 Output_data_got<32, false>* got_;
876 Output_data_plt_i386* plt_;
877 // The GOT PLT section.
878 Output_data_got_plt_i386* got_plt_;
879 // The GOT section for IRELATIVE relocations.
880 Output_data_space* got_irelative_;
881 // The GOT section for TLSDESC relocations.
882 Output_data_got<32, false>* got_tlsdesc_;
883 // The _GLOBAL_OFFSET_TABLE_ symbol.
884 Symbol* global_offset_table_;
885 // The dynamic reloc section.
886 Reloc_section* rel_dyn_;
887 // The section to use for IRELATIVE relocs.
888 Reloc_section* rel_irelative_;
889 // Relocs saved to avoid a COPY reloc.
890 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
891 // Offset of the GOT entry for the TLS module index.
892 unsigned int got_mod_index_offset_;
893 // True if the _TLS_MODULE_BASE_ symbol has been defined.
894 bool tls_base_symbol_defined_;
897 const Target::Target_info Target_i386::i386_info =
900 false, // is_big_endian
901 elfcpp::EM_386, // machine_code
902 false, // has_make_symbol
903 false, // has_resolve
904 true, // has_code_fill
905 true, // is_default_stack_executable
906 true, // can_icf_inline_merge_sections
908 "/usr/lib/libc.so.1", // dynamic_linker
909 0x08048000, // default_text_segment_address
910 0x1000, // abi_pagesize (overridable by -z max-page-size)
911 0x1000, // common_pagesize (overridable by -z common-page-size)
912 false, // isolate_execinstr
914 elfcpp::SHN_UNDEF, // small_common_shndx
915 elfcpp::SHN_UNDEF, // large_common_shndx
916 0, // small_common_section_flags
917 0, // large_common_section_flags
918 NULL, // attributes_section
919 NULL, // attributes_vendor
920 "_start", // entry_symbol_name
921 32, // hash_entry_size
924 // Get the GOT section, creating it if necessary.
926 Output_data_got<32, false>*
927 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
929 if (this->got_ == NULL)
931 gold_assert(symtab != NULL && layout != NULL);
933 this->got_ = new Output_data_got<32, false>();
935 // When using -z now, we can treat .got.plt as a relro section.
936 // Without -z now, it is modified after program startup by lazy
938 bool is_got_plt_relro = parameters->options().now();
939 Output_section_order got_order = (is_got_plt_relro
942 Output_section_order got_plt_order = (is_got_plt_relro
944 : ORDER_NON_RELRO_FIRST);
946 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
948 | elfcpp::SHF_WRITE),
949 this->got_, got_order, true);
951 this->got_plt_ = new Output_data_got_plt_i386(layout);
952 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
954 | elfcpp::SHF_WRITE),
955 this->got_plt_, got_plt_order,
958 // The first three entries are reserved.
959 this->got_plt_->set_current_data_size(3 * 4);
961 if (!is_got_plt_relro)
963 // Those bytes can go into the relro segment.
964 layout->increase_relro(3 * 4);
967 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
968 this->global_offset_table_ =
969 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
970 Symbol_table::PREDEFINED,
972 0, 0, elfcpp::STT_OBJECT,
974 elfcpp::STV_HIDDEN, 0,
977 // If there are any IRELATIVE relocations, they get GOT entries
978 // in .got.plt after the jump slot relocations.
979 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
980 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
982 | elfcpp::SHF_WRITE),
983 this->got_irelative_,
984 got_plt_order, is_got_plt_relro);
986 // If there are any TLSDESC relocations, they get GOT entries in
987 // .got.plt after the jump slot entries.
988 this->got_tlsdesc_ = new Output_data_got<32, false>();
989 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
991 | elfcpp::SHF_WRITE),
993 got_plt_order, is_got_plt_relro);
999 // Get the dynamic reloc section, creating it if necessary.
1001 Target_i386::Reloc_section*
1002 Target_i386::rel_dyn_section(Layout* layout)
1004 if (this->rel_dyn_ == NULL)
1006 gold_assert(layout != NULL);
1007 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
1008 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1009 elfcpp::SHF_ALLOC, this->rel_dyn_,
1010 ORDER_DYNAMIC_RELOCS, false);
1012 return this->rel_dyn_;
1015 // Get the section to use for IRELATIVE relocs, creating it if
1016 // necessary. These go in .rel.dyn, but only after all other dynamic
1017 // relocations. They need to follow the other dynamic relocations so
1018 // that they can refer to global variables initialized by those
1021 Target_i386::Reloc_section*
1022 Target_i386::rel_irelative_section(Layout* layout)
1024 if (this->rel_irelative_ == NULL)
1026 // Make sure we have already create the dynamic reloc section.
1027 this->rel_dyn_section(layout);
1028 this->rel_irelative_ = new Reloc_section(false);
1029 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1030 elfcpp::SHF_ALLOC, this->rel_irelative_,
1031 ORDER_DYNAMIC_RELOCS, false);
1032 gold_assert(this->rel_dyn_->output_section()
1033 == this->rel_irelative_->output_section());
1035 return this->rel_irelative_;
1038 // Write the first three reserved words of the .got.plt section.
1039 // The remainder of the section is written while writing the PLT
1040 // in Output_data_plt_i386::do_write.
1043 Output_data_got_plt_i386::do_write(Output_file* of)
1045 // The first entry in the GOT is the address of the .dynamic section
1046 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1047 // We saved space for them when we created the section in
1048 // Target_i386::got_section.
1049 const off_t got_file_offset = this->offset();
1050 gold_assert(this->data_size() >= 12);
1051 unsigned char* const got_view = of->get_output_view(got_file_offset, 12);
1052 Output_section* dynamic = this->layout_->dynamic_section();
1053 uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1054 elfcpp::Swap<32, false>::writeval(got_view, dynamic_addr);
1055 memset(got_view + 4, 0, 8);
1056 of->write_output_view(got_file_offset, 12, got_view);
1059 // Create the PLT section. The ordinary .got section is an argument,
1060 // since we need to refer to the start. We also create our own .got
1061 // section just for PLT entries.
1063 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
1065 Output_data_got_plt_i386* got_plt,
1066 Output_data_space* got_irelative)
1067 : Output_section_data(addralign),
1068 tls_desc_rel_(NULL), irelative_rel_(NULL), got_plt_(got_plt),
1069 got_irelative_(got_irelative), count_(0), irelative_count_(0),
1070 global_ifuncs_(), local_ifuncs_()
1072 this->rel_ = new Reloc_section(false);
1073 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1074 elfcpp::SHF_ALLOC, this->rel_,
1075 ORDER_DYNAMIC_PLT_RELOCS, false);
1079 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
1081 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1082 // linker, and so do we.
1086 // Add an entry to the PLT.
1089 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
1092 gold_assert(!gsym->has_plt_offset());
1094 // Every PLT entry needs a reloc.
1095 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1096 && gsym->can_use_relative_reloc(false))
1098 gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
1099 ++this->irelative_count_;
1100 section_offset_type got_offset =
1101 this->got_irelative_->current_data_size();
1102 this->got_irelative_->set_current_data_size(got_offset + 4);
1103 Reloc_section* rel = this->rel_irelative(symtab, layout);
1104 rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
1105 this->got_irelative_, got_offset);
1106 struct Global_ifunc gi;
1108 gi.got_offset = got_offset;
1109 this->global_ifuncs_.push_back(gi);
1113 // When setting the PLT offset we skip the initial reserved PLT
1115 gsym->set_plt_offset((this->count_ + 1) * this->get_plt_entry_size());
1119 section_offset_type got_offset = this->got_plt_->current_data_size();
1121 // Every PLT entry needs a GOT entry which points back to the
1122 // PLT entry (this will be changed by the dynamic linker,
1123 // normally lazily when the function is called).
1124 this->got_plt_->set_current_data_size(got_offset + 4);
1126 gsym->set_needs_dynsym_entry();
1127 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
1131 // Note that we don't need to save the symbol. The contents of the
1132 // PLT are independent of which symbols are used. The symbols only
1133 // appear in the relocations.
1136 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1140 Output_data_plt_i386::add_local_ifunc_entry(
1141 Symbol_table* symtab,
1143 Sized_relobj_file<32, false>* relobj,
1144 unsigned int local_sym_index)
1146 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1147 ++this->irelative_count_;
1149 section_offset_type got_offset = this->got_irelative_->current_data_size();
1151 // Every PLT entry needs a GOT entry which points back to the PLT
1153 this->got_irelative_->set_current_data_size(got_offset + 4);
1155 // Every PLT entry needs a reloc.
1156 Reloc_section* rel = this->rel_irelative(symtab, layout);
1157 rel->add_symbolless_local_addend(relobj, local_sym_index,
1158 elfcpp::R_386_IRELATIVE,
1159 this->got_irelative_, got_offset);
1161 struct Local_ifunc li;
1163 li.local_sym_index = local_sym_index;
1164 li.got_offset = got_offset;
1165 this->local_ifuncs_.push_back(li);
1170 // Return where the TLS_DESC relocations should go, creating it if
1171 // necessary. These follow the JUMP_SLOT relocations.
1173 Output_data_plt_i386::Reloc_section*
1174 Output_data_plt_i386::rel_tls_desc(Layout* layout)
1176 if (this->tls_desc_rel_ == NULL)
1178 this->tls_desc_rel_ = new Reloc_section(false);
1179 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1180 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
1181 ORDER_DYNAMIC_PLT_RELOCS, false);
1182 gold_assert(this->tls_desc_rel_->output_section()
1183 == this->rel_->output_section());
1185 return this->tls_desc_rel_;
1188 // Return where the IRELATIVE relocations should go in the PLT. These
1189 // follow the JUMP_SLOT and TLS_DESC relocations.
1191 Output_data_plt_i386::Reloc_section*
1192 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
1194 if (this->irelative_rel_ == NULL)
1196 // Make sure we have a place for the TLS_DESC relocations, in
1197 // case we see any later on.
1198 this->rel_tls_desc(layout);
1199 this->irelative_rel_ = new Reloc_section(false);
1200 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1201 elfcpp::SHF_ALLOC, this->irelative_rel_,
1202 ORDER_DYNAMIC_PLT_RELOCS, false);
1203 gold_assert(this->irelative_rel_->output_section()
1204 == this->rel_->output_section());
1206 if (parameters->doing_static_link())
1208 // A statically linked executable will only have a .rel.plt
1209 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1210 // symbols. The library will use these symbols to locate
1211 // the IRELATIVE relocs at program startup time.
1212 symtab->define_in_output_data("__rel_iplt_start", NULL,
1213 Symbol_table::PREDEFINED,
1214 this->irelative_rel_, 0, 0,
1215 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1216 elfcpp::STV_HIDDEN, 0, false, true);
1217 symtab->define_in_output_data("__rel_iplt_end", NULL,
1218 Symbol_table::PREDEFINED,
1219 this->irelative_rel_, 0, 0,
1220 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1221 elfcpp::STV_HIDDEN, 0, true, true);
1224 return this->irelative_rel_;
1227 // Return the PLT address to use for a global symbol.
1230 Output_data_plt_i386::address_for_global(const Symbol* gsym)
1232 uint64_t offset = 0;
1233 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1234 && gsym->can_use_relative_reloc(false))
1235 offset = (this->count_ + 1) * this->get_plt_entry_size();
1236 return this->address() + offset + gsym->plt_offset();
1239 // Return the PLT address to use for a local symbol. These are always
1240 // IRELATIVE relocs.
1243 Output_data_plt_i386::address_for_local(const Relobj* object,
1246 return (this->address()
1247 + (this->count_ + 1) * this->get_plt_entry_size()
1248 + object->local_plt_offset(r_sym));
1251 // The first entry in the PLT for an executable.
1253 const unsigned char Output_data_plt_i386_exec::first_plt_entry[plt_entry_size] =
1255 0xff, 0x35, // pushl contents of memory address
1256 0, 0, 0, 0, // replaced with address of .got + 4
1257 0xff, 0x25, // jmp indirect
1258 0, 0, 0, 0, // replaced with address of .got + 8
1259 0, 0, 0, 0 // unused
1263 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1265 elfcpp::Elf_types<32>::Elf_Addr got_address)
1267 memcpy(pov, first_plt_entry, plt_entry_size);
1268 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1269 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1272 // The first entry in the PLT for a shared object.
1274 const unsigned char Output_data_plt_i386_dyn::first_plt_entry[plt_entry_size] =
1276 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1277 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1278 0, 0, 0, 0 // unused
1282 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1284 elfcpp::Elf_types<32>::Elf_Addr)
1286 memcpy(pov, first_plt_entry, plt_entry_size);
1289 // Subsequent entries in the PLT for an executable.
1291 const unsigned char Output_data_plt_i386_exec::plt_entry[plt_entry_size] =
1293 0xff, 0x25, // jmp indirect
1294 0, 0, 0, 0, // replaced with address of symbol in .got
1295 0x68, // pushl immediate
1296 0, 0, 0, 0, // replaced with offset into relocation table
1297 0xe9, // jmp relative
1298 0, 0, 0, 0 // replaced with offset to start of .plt
1302 Output_data_plt_i386_exec::do_fill_plt_entry(
1304 elfcpp::Elf_types<32>::Elf_Addr got_address,
1305 unsigned int got_offset,
1306 unsigned int plt_offset,
1307 unsigned int plt_rel_offset)
1309 memcpy(pov, plt_entry, plt_entry_size);
1310 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1311 got_address + got_offset);
1312 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1313 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1317 // Subsequent entries in the PLT for a shared object.
1319 const unsigned char Output_data_plt_i386_dyn::plt_entry[plt_entry_size] =
1321 0xff, 0xa3, // jmp *offset(%ebx)
1322 0, 0, 0, 0, // replaced with offset of symbol in .got
1323 0x68, // pushl immediate
1324 0, 0, 0, 0, // replaced with offset into relocation table
1325 0xe9, // jmp relative
1326 0, 0, 0, 0 // replaced with offset to start of .plt
1330 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
1331 elfcpp::Elf_types<32>::Elf_Addr,
1332 unsigned int got_offset,
1333 unsigned int plt_offset,
1334 unsigned int plt_rel_offset)
1336 memcpy(pov, plt_entry, plt_entry_size);
1337 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1338 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1339 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1343 // The .eh_frame unwind information for the PLT.
1346 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1349 'z', // Augmentation: augmentation size included.
1350 'R', // Augmentation: FDE encoding included.
1351 '\0', // End of augmentation string.
1352 1, // Code alignment factor.
1353 0x7c, // Data alignment factor.
1354 8, // Return address column.
1355 1, // Augmentation size.
1356 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1357 | elfcpp::DW_EH_PE_sdata4),
1358 elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1359 elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1360 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1365 Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1367 0, 0, 0, 0, // Replaced with offset to .plt.
1368 0, 0, 0, 0, // Replaced with size of .plt.
1369 0, // Augmentation size.
1370 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
1371 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1372 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
1373 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1374 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1375 11, // Block length.
1376 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
1377 elfcpp::DW_OP_breg8, 0, // Push %eip.
1378 elfcpp::DW_OP_lit15, // Push 0xf.
1379 elfcpp::DW_OP_and, // & (%eip & 0xf).
1380 elfcpp::DW_OP_lit11, // Push 0xb.
1381 elfcpp::DW_OP_ge, // >= ((%eip & 0xf) >= 0xb)
1382 elfcpp::DW_OP_lit2, // Push 2.
1383 elfcpp::DW_OP_shl, // << (((%eip & 0xf) >= 0xb) << 2)
1384 elfcpp::DW_OP_plus, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1385 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1391 // Write out the PLT. This uses the hand-coded instructions above,
1392 // and adjusts them as needed. This is all specified by the i386 ELF
1393 // Processor Supplement.
1396 Output_data_plt_i386::do_write(Output_file* of)
1398 const off_t offset = this->offset();
1399 const section_size_type oview_size =
1400 convert_to_section_size_type(this->data_size());
1401 unsigned char* const oview = of->get_output_view(offset, oview_size);
1403 const off_t got_file_offset = this->got_plt_->offset();
1404 gold_assert(parameters->incremental_update()
1405 || (got_file_offset + this->got_plt_->data_size()
1406 == this->got_irelative_->offset()));
1407 const section_size_type got_size =
1408 convert_to_section_size_type(this->got_plt_->data_size()
1409 + this->got_irelative_->data_size());
1411 unsigned char* const got_view = of->get_output_view(got_file_offset,
1414 unsigned char* pov = oview;
1416 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1417 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1419 this->fill_first_plt_entry(pov, got_address);
1420 pov += this->get_plt_entry_size();
1422 // The first three entries in the GOT are reserved, and are written
1423 // by Output_data_got_plt_i386::do_write.
1424 unsigned char* got_pov = got_view + 12;
1426 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1428 unsigned int plt_offset = this->get_plt_entry_size();
1429 unsigned int plt_rel_offset = 0;
1430 unsigned int got_offset = 12;
1431 const unsigned int count = this->count_ + this->irelative_count_;
1432 for (unsigned int i = 0;
1435 pov += this->get_plt_entry_size(),
1437 plt_offset += this->get_plt_entry_size(),
1438 plt_rel_offset += rel_size,
1441 // Set and adjust the PLT entry itself.
1442 unsigned int lazy_offset = this->fill_plt_entry(pov,
1448 // Set the entry in the GOT.
1449 elfcpp::Swap<32, false>::writeval(got_pov,
1450 plt_address + plt_offset + lazy_offset);
1453 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1454 // the GOT to point to the actual symbol value, rather than point to
1455 // the PLT entry. That will let the dynamic linker call the right
1456 // function when resolving IRELATIVE relocations.
1457 unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1458 for (std::vector<Global_ifunc>::const_iterator p =
1459 this->global_ifuncs_.begin();
1460 p != this->global_ifuncs_.end();
1463 const Sized_symbol<32>* ssym =
1464 static_cast<const Sized_symbol<32>*>(p->sym);
1465 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1469 for (std::vector<Local_ifunc>::const_iterator p =
1470 this->local_ifuncs_.begin();
1471 p != this->local_ifuncs_.end();
1474 const Symbol_value<32>* psymval =
1475 p->object->local_symbol(p->local_sym_index);
1476 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1477 psymval->value(p->object, 0));
1480 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1481 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1483 of->write_output_view(offset, oview_size, oview);
1484 of->write_output_view(got_file_offset, got_size, got_view);
1487 // Create the PLT section.
1490 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1492 if (this->plt_ == NULL)
1494 // Create the GOT sections first.
1495 this->got_section(symtab, layout);
1497 const bool dyn = parameters->options().output_is_position_independent();
1498 this->plt_ = this->make_data_plt(layout,
1500 this->got_irelative_,
1503 // Add unwind information if requested.
1504 if (parameters->options().ld_generated_unwind_info())
1505 this->plt_->add_eh_frame(layout);
1507 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1509 | elfcpp::SHF_EXECINSTR),
1510 this->plt_, ORDER_PLT, false);
1512 // Make the sh_info field of .rel.plt point to .plt.
1513 Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1514 rel_plt_os->set_info_section(this->plt_->output_section());
1518 // Create a PLT entry for a global symbol.
1521 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1523 if (gsym->has_plt_offset())
1525 if (this->plt_ == NULL)
1526 this->make_plt_section(symtab, layout);
1527 this->plt_->add_entry(symtab, layout, gsym);
1530 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1533 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1534 Sized_relobj_file<32, false>* relobj,
1535 unsigned int local_sym_index)
1537 if (relobj->local_has_plt_offset(local_sym_index))
1539 if (this->plt_ == NULL)
1540 this->make_plt_section(symtab, layout);
1541 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1544 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1547 // Return the number of entries in the PLT.
1550 Target_i386::plt_entry_count() const
1552 if (this->plt_ == NULL)
1554 return this->plt_->entry_count();
1557 // Return the offset of the first non-reserved PLT entry.
1560 Target_i386::first_plt_entry_offset() const
1562 return this->plt_->first_plt_entry_offset();
1565 // Return the size of each PLT entry.
1568 Target_i386::plt_entry_size() const
1570 return this->plt_->get_plt_entry_size();
1573 // Get the section to use for TLS_DESC relocations.
1575 Target_i386::Reloc_section*
1576 Target_i386::rel_tls_desc_section(Layout* layout) const
1578 return this->plt_section()->rel_tls_desc(layout);
1581 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1584 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1586 if (this->tls_base_symbol_defined_)
1589 Output_segment* tls_segment = layout->tls_segment();
1590 if (tls_segment != NULL)
1592 bool is_exec = parameters->options().output_is_executable();
1593 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1594 Symbol_table::PREDEFINED,
1598 elfcpp::STV_HIDDEN, 0,
1600 ? Symbol::SEGMENT_END
1601 : Symbol::SEGMENT_START),
1604 this->tls_base_symbol_defined_ = true;
1607 // Create a GOT entry for the TLS module index.
1610 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1611 Sized_relobj_file<32, false>* object)
1613 if (this->got_mod_index_offset_ == -1U)
1615 gold_assert(symtab != NULL && layout != NULL && object != NULL);
1616 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1617 Output_data_got<32, false>* got = this->got_section(symtab, layout);
1618 unsigned int got_offset = got->add_constant(0);
1619 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1621 got->add_constant(0);
1622 this->got_mod_index_offset_ = got_offset;
1624 return this->got_mod_index_offset_;
1627 // Optimize the TLS relocation type based on what we know about the
1628 // symbol. IS_FINAL is true if the final address of this symbol is
1629 // known at link time.
1631 tls::Tls_optimization
1632 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1634 // If we are generating a shared library, then we can't do anything
1636 if (parameters->options().shared())
1637 return tls::TLSOPT_NONE;
1641 case elfcpp::R_386_TLS_GD:
1642 case elfcpp::R_386_TLS_GOTDESC:
1643 case elfcpp::R_386_TLS_DESC_CALL:
1644 // These are General-Dynamic which permits fully general TLS
1645 // access. Since we know that we are generating an executable,
1646 // we can convert this to Initial-Exec. If we also know that
1647 // this is a local symbol, we can further switch to Local-Exec.
1649 return tls::TLSOPT_TO_LE;
1650 return tls::TLSOPT_TO_IE;
1652 case elfcpp::R_386_TLS_LDM:
1653 // This is Local-Dynamic, which refers to a local symbol in the
1654 // dynamic TLS block. Since we know that we generating an
1655 // executable, we can switch to Local-Exec.
1656 return tls::TLSOPT_TO_LE;
1658 case elfcpp::R_386_TLS_LDO_32:
1659 // Another type of Local-Dynamic relocation.
1660 return tls::TLSOPT_TO_LE;
1662 case elfcpp::R_386_TLS_IE:
1663 case elfcpp::R_386_TLS_GOTIE:
1664 case elfcpp::R_386_TLS_IE_32:
1665 // These are Initial-Exec relocs which get the thread offset
1666 // from the GOT. If we know that we are linking against the
1667 // local symbol, we can switch to Local-Exec, which links the
1668 // thread offset into the instruction.
1670 return tls::TLSOPT_TO_LE;
1671 return tls::TLSOPT_NONE;
1673 case elfcpp::R_386_TLS_LE:
1674 case elfcpp::R_386_TLS_LE_32:
1675 // When we already have Local-Exec, there is nothing further we
1677 return tls::TLSOPT_NONE;
1684 // Get the Reference_flags for a particular relocation.
1687 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1691 case elfcpp::R_386_NONE:
1692 case elfcpp::R_386_GNU_VTINHERIT:
1693 case elfcpp::R_386_GNU_VTENTRY:
1694 case elfcpp::R_386_GOTPC:
1695 // No symbol reference.
1698 case elfcpp::R_386_32:
1699 case elfcpp::R_386_16:
1700 case elfcpp::R_386_8:
1701 return Symbol::ABSOLUTE_REF;
1703 case elfcpp::R_386_PC32:
1704 case elfcpp::R_386_PC16:
1705 case elfcpp::R_386_PC8:
1706 case elfcpp::R_386_GOTOFF:
1707 return Symbol::RELATIVE_REF;
1709 case elfcpp::R_386_PLT32:
1710 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1712 case elfcpp::R_386_GOT32:
1713 case elfcpp::R_386_GOT32X:
1715 return Symbol::ABSOLUTE_REF;
1717 case elfcpp::R_386_TLS_GD: // Global-dynamic
1718 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1719 case elfcpp::R_386_TLS_DESC_CALL:
1720 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1721 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1722 case elfcpp::R_386_TLS_IE: // Initial-exec
1723 case elfcpp::R_386_TLS_IE_32:
1724 case elfcpp::R_386_TLS_GOTIE:
1725 case elfcpp::R_386_TLS_LE: // Local-exec
1726 case elfcpp::R_386_TLS_LE_32:
1727 return Symbol::TLS_REF;
1729 case elfcpp::R_386_COPY:
1730 case elfcpp::R_386_GLOB_DAT:
1731 case elfcpp::R_386_JUMP_SLOT:
1732 case elfcpp::R_386_RELATIVE:
1733 case elfcpp::R_386_IRELATIVE:
1734 case elfcpp::R_386_TLS_TPOFF:
1735 case elfcpp::R_386_TLS_DTPMOD32:
1736 case elfcpp::R_386_TLS_DTPOFF32:
1737 case elfcpp::R_386_TLS_TPOFF32:
1738 case elfcpp::R_386_TLS_DESC:
1739 case elfcpp::R_386_32PLT:
1740 case elfcpp::R_386_TLS_GD_32:
1741 case elfcpp::R_386_TLS_GD_PUSH:
1742 case elfcpp::R_386_TLS_GD_CALL:
1743 case elfcpp::R_386_TLS_GD_POP:
1744 case elfcpp::R_386_TLS_LDM_32:
1745 case elfcpp::R_386_TLS_LDM_PUSH:
1746 case elfcpp::R_386_TLS_LDM_CALL:
1747 case elfcpp::R_386_TLS_LDM_POP:
1748 case elfcpp::R_386_USED_BY_INTEL_200:
1750 // Not expected. We will give an error later.
1755 // Report an unsupported relocation against a local symbol.
1758 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1759 unsigned int r_type)
1761 gold_error(_("%s: unsupported reloc %u against local symbol"),
1762 object->name().c_str(), r_type);
1765 // Return whether we need to make a PLT entry for a relocation of a
1766 // given type against a STT_GNU_IFUNC symbol.
1769 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1770 Sized_relobj_file<32, false>* object,
1771 unsigned int r_type)
1773 int flags = Scan::get_reference_flags(r_type);
1774 if (flags & Symbol::TLS_REF)
1775 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1776 object->name().c_str(), r_type);
1780 // Scan a relocation for a local symbol.
1783 Target_i386::Scan::local(Symbol_table* symtab,
1785 Target_i386* target,
1786 Sized_relobj_file<32, false>* object,
1787 unsigned int data_shndx,
1788 Output_section* output_section,
1789 const elfcpp::Rel<32, false>& reloc,
1790 unsigned int r_type,
1791 const elfcpp::Sym<32, false>& lsym,
1797 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1798 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1799 && this->reloc_needs_plt_for_ifunc(object, r_type))
1801 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1802 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1807 case elfcpp::R_386_NONE:
1808 case elfcpp::R_386_GNU_VTINHERIT:
1809 case elfcpp::R_386_GNU_VTENTRY:
1812 case elfcpp::R_386_32:
1813 // If building a shared library (or a position-independent
1814 // executable), we need to create a dynamic relocation for
1815 // this location. The relocation applied at link time will
1816 // apply the link-time value, so we flag the location with
1817 // an R_386_RELATIVE relocation so the dynamic loader can
1818 // relocate it easily.
1819 if (parameters->options().output_is_position_independent())
1821 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1822 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1823 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1824 output_section, data_shndx,
1825 reloc.get_r_offset());
1829 case elfcpp::R_386_16:
1830 case elfcpp::R_386_8:
1831 // If building a shared library (or a position-independent
1832 // executable), we need to create a dynamic relocation for
1833 // this location. Because the addend needs to remain in the
1834 // data section, we need to be careful not to apply this
1835 // relocation statically.
1836 if (parameters->options().output_is_position_independent())
1838 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1839 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1840 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1841 rel_dyn->add_local(object, r_sym, r_type, output_section,
1842 data_shndx, reloc.get_r_offset());
1845 gold_assert(lsym.get_st_value() == 0);
1846 unsigned int shndx = lsym.get_st_shndx();
1848 shndx = object->adjust_sym_shndx(r_sym, shndx,
1851 object->error(_("section symbol %u has bad shndx %u"),
1854 rel_dyn->add_local_section(object, shndx,
1855 r_type, output_section,
1856 data_shndx, reloc.get_r_offset());
1861 case elfcpp::R_386_PC32:
1862 case elfcpp::R_386_PC16:
1863 case elfcpp::R_386_PC8:
1866 case elfcpp::R_386_PLT32:
1867 // Since we know this is a local symbol, we can handle this as a
1871 case elfcpp::R_386_GOTOFF:
1872 case elfcpp::R_386_GOTPC:
1873 // We need a GOT section.
1874 target->got_section(symtab, layout);
1877 case elfcpp::R_386_GOT32:
1878 case elfcpp::R_386_GOT32X:
1880 // We need GOT section.
1881 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1883 // If the relocation symbol isn't IFUNC,
1884 // and is local, then we will convert
1885 // mov foo@GOT(%reg), %reg
1887 // lea foo@GOTOFF(%reg), %reg
1888 // in Relocate::relocate.
1889 if (reloc.get_r_offset() >= 2
1890 && lsym.get_st_type() != elfcpp::STT_GNU_IFUNC)
1892 section_size_type stype;
1893 const unsigned char* view = object->section_contents(data_shndx,
1895 if (view[reloc.get_r_offset() - 2] == 0x8b)
1899 // Otherwise, the symbol requires a GOT entry.
1900 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1902 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1903 // lets function pointers compare correctly with shared
1904 // libraries. Otherwise we would need an IRELATIVE reloc.
1906 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1907 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1909 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1912 // If we are generating a shared object, we need to add a
1913 // dynamic RELATIVE relocation for this symbol's GOT entry.
1914 if (parameters->options().output_is_position_independent())
1916 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1917 unsigned int got_offset =
1918 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1919 rel_dyn->add_local_relative(object, r_sym,
1920 elfcpp::R_386_RELATIVE,
1927 // These are relocations which should only be seen by the
1928 // dynamic linker, and should never be seen here.
1929 case elfcpp::R_386_COPY:
1930 case elfcpp::R_386_GLOB_DAT:
1931 case elfcpp::R_386_JUMP_SLOT:
1932 case elfcpp::R_386_RELATIVE:
1933 case elfcpp::R_386_IRELATIVE:
1934 case elfcpp::R_386_TLS_TPOFF:
1935 case elfcpp::R_386_TLS_DTPMOD32:
1936 case elfcpp::R_386_TLS_DTPOFF32:
1937 case elfcpp::R_386_TLS_TPOFF32:
1938 case elfcpp::R_386_TLS_DESC:
1939 gold_error(_("%s: unexpected reloc %u in object file"),
1940 object->name().c_str(), r_type);
1943 // These are initial TLS relocs, which are expected when
1945 case elfcpp::R_386_TLS_GD: // Global-dynamic
1946 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1947 case elfcpp::R_386_TLS_DESC_CALL:
1948 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1949 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1950 case elfcpp::R_386_TLS_IE: // Initial-exec
1951 case elfcpp::R_386_TLS_IE_32:
1952 case elfcpp::R_386_TLS_GOTIE:
1953 case elfcpp::R_386_TLS_LE: // Local-exec
1954 case elfcpp::R_386_TLS_LE_32:
1956 bool output_is_shared = parameters->options().shared();
1957 const tls::Tls_optimization optimized_type
1958 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1961 case elfcpp::R_386_TLS_GD: // Global-dynamic
1962 if (optimized_type == tls::TLSOPT_NONE)
1964 // Create a pair of GOT entries for the module index and
1965 // dtv-relative offset.
1966 Output_data_got<32, false>* got
1967 = target->got_section(symtab, layout);
1968 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1969 unsigned int shndx = lsym.get_st_shndx();
1971 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1973 object->error(_("local symbol %u has bad shndx %u"),
1976 got->add_local_pair_with_rel(object, r_sym, shndx,
1978 target->rel_dyn_section(layout),
1979 elfcpp::R_386_TLS_DTPMOD32);
1981 else if (optimized_type != tls::TLSOPT_TO_LE)
1982 unsupported_reloc_local(object, r_type);
1985 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1986 target->define_tls_base_symbol(symtab, layout);
1987 if (optimized_type == tls::TLSOPT_NONE)
1989 // Create a double GOT entry with an R_386_TLS_DESC
1990 // reloc. The R_386_TLS_DESC reloc is resolved
1991 // lazily, so the GOT entry needs to be in an area in
1992 // .got.plt, not .got. Call got_section to make sure
1993 // the section has been created.
1994 target->got_section(symtab, layout);
1995 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1996 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1997 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1999 unsigned int got_offset = got->add_constant(0);
2000 // The local symbol value is stored in the second
2002 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
2003 // That set the GOT offset of the local symbol to
2004 // point to the second entry, but we want it to
2005 // point to the first.
2006 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2008 Reloc_section* rt = target->rel_tls_desc_section(layout);
2009 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
2012 else if (optimized_type != tls::TLSOPT_TO_LE)
2013 unsupported_reloc_local(object, r_type);
2016 case elfcpp::R_386_TLS_DESC_CALL:
2019 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2020 if (optimized_type == tls::TLSOPT_NONE)
2022 // Create a GOT entry for the module index.
2023 target->got_mod_index_entry(symtab, layout, object);
2025 else if (optimized_type != tls::TLSOPT_TO_LE)
2026 unsupported_reloc_local(object, r_type);
2029 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2032 case elfcpp::R_386_TLS_IE: // Initial-exec
2033 case elfcpp::R_386_TLS_IE_32:
2034 case elfcpp::R_386_TLS_GOTIE:
2035 layout->set_has_static_tls();
2036 if (optimized_type == tls::TLSOPT_NONE)
2038 // For the R_386_TLS_IE relocation, we need to create a
2039 // dynamic relocation when building a shared library.
2040 if (r_type == elfcpp::R_386_TLS_IE
2041 && parameters->options().shared())
2043 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2045 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2046 rel_dyn->add_local_relative(object, r_sym,
2047 elfcpp::R_386_RELATIVE,
2048 output_section, data_shndx,
2049 reloc.get_r_offset());
2051 // Create a GOT entry for the tp-relative offset.
2052 Output_data_got<32, false>* got
2053 = target->got_section(symtab, layout);
2054 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2055 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2056 ? elfcpp::R_386_TLS_TPOFF32
2057 : elfcpp::R_386_TLS_TPOFF);
2058 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2059 ? GOT_TYPE_TLS_OFFSET
2060 : GOT_TYPE_TLS_NOFFSET);
2061 got->add_local_with_rel(object, r_sym, got_type,
2062 target->rel_dyn_section(layout),
2065 else if (optimized_type != tls::TLSOPT_TO_LE)
2066 unsupported_reloc_local(object, r_type);
2069 case elfcpp::R_386_TLS_LE: // Local-exec
2070 case elfcpp::R_386_TLS_LE_32:
2071 layout->set_has_static_tls();
2072 if (output_is_shared)
2074 // We need to create a dynamic relocation.
2075 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2076 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2077 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2078 ? elfcpp::R_386_TLS_TPOFF32
2079 : elfcpp::R_386_TLS_TPOFF);
2080 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2081 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
2082 data_shndx, reloc.get_r_offset());
2092 case elfcpp::R_386_32PLT:
2093 case elfcpp::R_386_TLS_GD_32:
2094 case elfcpp::R_386_TLS_GD_PUSH:
2095 case elfcpp::R_386_TLS_GD_CALL:
2096 case elfcpp::R_386_TLS_GD_POP:
2097 case elfcpp::R_386_TLS_LDM_32:
2098 case elfcpp::R_386_TLS_LDM_PUSH:
2099 case elfcpp::R_386_TLS_LDM_CALL:
2100 case elfcpp::R_386_TLS_LDM_POP:
2101 case elfcpp::R_386_USED_BY_INTEL_200:
2103 unsupported_reloc_local(object, r_type);
2108 // Report an unsupported relocation against a global symbol.
2111 Target_i386::Scan::unsupported_reloc_global(
2112 Sized_relobj_file<32, false>* object,
2113 unsigned int r_type,
2116 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2117 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2121 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
2125 case elfcpp::R_386_32:
2126 case elfcpp::R_386_16:
2127 case elfcpp::R_386_8:
2128 case elfcpp::R_386_GOTOFF:
2129 case elfcpp::R_386_GOT32:
2130 case elfcpp::R_386_GOT32X:
2141 Target_i386::Scan::local_reloc_may_be_function_pointer(
2145 Sized_relobj_file<32, false>* ,
2148 const elfcpp::Rel<32, false>& ,
2149 unsigned int r_type,
2150 const elfcpp::Sym<32, false>&)
2152 return possible_function_pointer_reloc(r_type);
2156 Target_i386::Scan::global_reloc_may_be_function_pointer(
2160 Sized_relobj_file<32, false>* ,
2163 const elfcpp::Rel<32, false>& ,
2164 unsigned int r_type,
2167 return possible_function_pointer_reloc(r_type);
2170 // Scan a relocation for a global symbol.
2173 Target_i386::Scan::global(Symbol_table* symtab,
2175 Target_i386* target,
2176 Sized_relobj_file<32, false>* object,
2177 unsigned int data_shndx,
2178 Output_section* output_section,
2179 const elfcpp::Rel<32, false>& reloc,
2180 unsigned int r_type,
2183 // A STT_GNU_IFUNC symbol may require a PLT entry.
2184 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2185 && this->reloc_needs_plt_for_ifunc(object, r_type))
2186 target->make_plt_entry(symtab, layout, gsym);
2190 case elfcpp::R_386_NONE:
2191 case elfcpp::R_386_GNU_VTINHERIT:
2192 case elfcpp::R_386_GNU_VTENTRY:
2195 case elfcpp::R_386_32:
2196 case elfcpp::R_386_16:
2197 case elfcpp::R_386_8:
2199 // Make a PLT entry if necessary.
2200 if (gsym->needs_plt_entry())
2202 target->make_plt_entry(symtab, layout, gsym);
2203 // Since this is not a PC-relative relocation, we may be
2204 // taking the address of a function. In that case we need to
2205 // set the entry in the dynamic symbol table to the address of
2207 if (gsym->is_from_dynobj() && !parameters->options().shared())
2208 gsym->set_needs_dynsym_value();
2210 // Make a dynamic relocation if necessary.
2211 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2213 if (!parameters->options().output_is_position_independent()
2214 && gsym->may_need_copy_reloc())
2216 target->copy_reloc(symtab, layout, object,
2217 data_shndx, output_section, gsym, reloc);
2219 else if (r_type == elfcpp::R_386_32
2220 && gsym->type() == elfcpp::STT_GNU_IFUNC
2221 && gsym->can_use_relative_reloc(false)
2222 && !gsym->is_from_dynobj()
2223 && !gsym->is_undefined()
2224 && !gsym->is_preemptible())
2226 // Use an IRELATIVE reloc for a locally defined
2227 // STT_GNU_IFUNC symbol. This makes a function
2228 // address in a PIE executable match the address in a
2229 // shared library that it links against.
2230 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
2231 rel_dyn->add_symbolless_global_addend(gsym,
2232 elfcpp::R_386_IRELATIVE,
2235 reloc.get_r_offset());
2237 else if (r_type == elfcpp::R_386_32
2238 && gsym->can_use_relative_reloc(false))
2240 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2241 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2242 output_section, object,
2243 data_shndx, reloc.get_r_offset());
2247 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2248 rel_dyn->add_global(gsym, r_type, output_section, object,
2249 data_shndx, reloc.get_r_offset());
2255 case elfcpp::R_386_PC32:
2256 case elfcpp::R_386_PC16:
2257 case elfcpp::R_386_PC8:
2259 // Make a PLT entry if necessary.
2260 if (gsym->needs_plt_entry())
2262 // These relocations are used for function calls only in
2263 // non-PIC code. For a 32-bit relocation in a shared library,
2264 // we'll need a text relocation anyway, so we can skip the
2265 // PLT entry and let the dynamic linker bind the call directly
2266 // to the target. For smaller relocations, we should use a
2267 // PLT entry to ensure that the call can reach.
2268 if (!parameters->options().shared()
2269 || r_type != elfcpp::R_386_PC32)
2270 target->make_plt_entry(symtab, layout, gsym);
2272 // Make a dynamic relocation if necessary.
2273 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2275 if (parameters->options().output_is_executable()
2276 && gsym->may_need_copy_reloc())
2278 target->copy_reloc(symtab, layout, object,
2279 data_shndx, output_section, gsym, reloc);
2283 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2284 rel_dyn->add_global(gsym, r_type, output_section, object,
2285 data_shndx, reloc.get_r_offset());
2291 case elfcpp::R_386_GOT32:
2292 case elfcpp::R_386_GOT32X:
2294 // The symbol requires a GOT section.
2295 Output_data_got<32, false>* got = target->got_section(symtab, layout);
2297 // If we convert this from
2298 // mov foo@GOT(%reg), %reg
2300 // lea foo@GOTOFF(%reg), %reg
2301 // in Relocate::relocate, then there is nothing to do here.
2302 if (reloc.get_r_offset() >= 2
2303 && Target_i386::can_convert_mov_to_lea(gsym))
2305 section_size_type stype;
2306 const unsigned char* view = object->section_contents(data_shndx,
2308 if (view[reloc.get_r_offset() - 2] == 0x8b)
2312 if (gsym->final_value_is_known())
2314 // For a STT_GNU_IFUNC symbol we want the PLT address.
2315 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2316 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2318 got->add_global(gsym, GOT_TYPE_STANDARD);
2322 // If this symbol is not fully resolved, we need to add a
2323 // GOT entry with a dynamic relocation.
2324 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2326 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2328 // 1) The symbol may be defined in some other module.
2330 // 2) We are building a shared library and this is a
2331 // protected symbol; using GLOB_DAT means that the dynamic
2332 // linker can use the address of the PLT in the main
2333 // executable when appropriate so that function address
2334 // comparisons work.
2336 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2337 // code, again so that function address comparisons work.
2338 if (gsym->is_from_dynobj()
2339 || gsym->is_undefined()
2340 || gsym->is_preemptible()
2341 || (gsym->visibility() == elfcpp::STV_PROTECTED
2342 && parameters->options().shared())
2343 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2344 && parameters->options().output_is_position_independent()))
2345 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2346 rel_dyn, elfcpp::R_386_GLOB_DAT);
2349 // For a STT_GNU_IFUNC symbol we want to write the PLT
2350 // offset into the GOT, so that function pointer
2351 // comparisons work correctly.
2353 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2354 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2357 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2358 // Tell the dynamic linker to use the PLT address
2359 // when resolving relocations.
2360 if (gsym->is_from_dynobj()
2361 && !parameters->options().shared())
2362 gsym->set_needs_dynsym_value();
2366 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2367 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2375 case elfcpp::R_386_PLT32:
2376 // If the symbol is fully resolved, this is just a PC32 reloc.
2377 // Otherwise we need a PLT entry.
2378 if (gsym->final_value_is_known())
2380 // If building a shared library, we can also skip the PLT entry
2381 // if the symbol is defined in the output file and is protected
2383 if (gsym->is_defined()
2384 && !gsym->is_from_dynobj()
2385 && !gsym->is_preemptible())
2387 target->make_plt_entry(symtab, layout, gsym);
2390 case elfcpp::R_386_GOTOFF:
2391 case elfcpp::R_386_GOTPC:
2392 // We need a GOT section.
2393 target->got_section(symtab, layout);
2396 // These are relocations which should only be seen by the
2397 // dynamic linker, and should never be seen here.
2398 case elfcpp::R_386_COPY:
2399 case elfcpp::R_386_GLOB_DAT:
2400 case elfcpp::R_386_JUMP_SLOT:
2401 case elfcpp::R_386_RELATIVE:
2402 case elfcpp::R_386_IRELATIVE:
2403 case elfcpp::R_386_TLS_TPOFF:
2404 case elfcpp::R_386_TLS_DTPMOD32:
2405 case elfcpp::R_386_TLS_DTPOFF32:
2406 case elfcpp::R_386_TLS_TPOFF32:
2407 case elfcpp::R_386_TLS_DESC:
2408 gold_error(_("%s: unexpected reloc %u in object file"),
2409 object->name().c_str(), r_type);
2412 // These are initial tls relocs, which are expected when
2414 case elfcpp::R_386_TLS_GD: // Global-dynamic
2415 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2416 case elfcpp::R_386_TLS_DESC_CALL:
2417 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2418 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2419 case elfcpp::R_386_TLS_IE: // Initial-exec
2420 case elfcpp::R_386_TLS_IE_32:
2421 case elfcpp::R_386_TLS_GOTIE:
2422 case elfcpp::R_386_TLS_LE: // Local-exec
2423 case elfcpp::R_386_TLS_LE_32:
2425 const bool is_final = gsym->final_value_is_known();
2426 const tls::Tls_optimization optimized_type
2427 = Target_i386::optimize_tls_reloc(is_final, r_type);
2430 case elfcpp::R_386_TLS_GD: // Global-dynamic
2431 if (optimized_type == tls::TLSOPT_NONE)
2433 // Create a pair of GOT entries for the module index and
2434 // dtv-relative offset.
2435 Output_data_got<32, false>* got
2436 = target->got_section(symtab, layout);
2437 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2438 target->rel_dyn_section(layout),
2439 elfcpp::R_386_TLS_DTPMOD32,
2440 elfcpp::R_386_TLS_DTPOFF32);
2442 else if (optimized_type == tls::TLSOPT_TO_IE)
2444 // Create a GOT entry for the tp-relative offset.
2445 Output_data_got<32, false>* got
2446 = target->got_section(symtab, layout);
2447 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2448 target->rel_dyn_section(layout),
2449 elfcpp::R_386_TLS_TPOFF);
2451 else if (optimized_type != tls::TLSOPT_TO_LE)
2452 unsupported_reloc_global(object, r_type, gsym);
2455 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
2456 target->define_tls_base_symbol(symtab, layout);
2457 if (optimized_type == tls::TLSOPT_NONE)
2459 // Create a double GOT entry with an R_386_TLS_DESC
2460 // reloc. The R_386_TLS_DESC reloc is resolved
2461 // lazily, so the GOT entry needs to be in an area in
2462 // .got.plt, not .got. Call got_section to make sure
2463 // the section has been created.
2464 target->got_section(symtab, layout);
2465 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2466 Reloc_section* rt = target->rel_tls_desc_section(layout);
2467 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2468 elfcpp::R_386_TLS_DESC, 0);
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_DESC_CALL:
2486 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2487 if (optimized_type == tls::TLSOPT_NONE)
2489 // Create a GOT entry for the module index.
2490 target->got_mod_index_entry(symtab, layout, object);
2492 else if (optimized_type != tls::TLSOPT_TO_LE)
2493 unsupported_reloc_global(object, r_type, gsym);
2496 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2499 case elfcpp::R_386_TLS_IE: // Initial-exec
2500 case elfcpp::R_386_TLS_IE_32:
2501 case elfcpp::R_386_TLS_GOTIE:
2502 layout->set_has_static_tls();
2503 if (optimized_type == tls::TLSOPT_NONE)
2505 // For the R_386_TLS_IE relocation, we need to create a
2506 // dynamic relocation when building a shared library.
2507 if (r_type == elfcpp::R_386_TLS_IE
2508 && parameters->options().shared())
2510 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2511 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2512 output_section, object,
2514 reloc.get_r_offset());
2516 // Create a GOT entry for the tp-relative offset.
2517 Output_data_got<32, false>* got
2518 = target->got_section(symtab, layout);
2519 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2520 ? elfcpp::R_386_TLS_TPOFF32
2521 : elfcpp::R_386_TLS_TPOFF);
2522 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2523 ? GOT_TYPE_TLS_OFFSET
2524 : GOT_TYPE_TLS_NOFFSET);
2525 got->add_global_with_rel(gsym, got_type,
2526 target->rel_dyn_section(layout),
2529 else if (optimized_type != tls::TLSOPT_TO_LE)
2530 unsupported_reloc_global(object, r_type, gsym);
2533 case elfcpp::R_386_TLS_LE: // Local-exec
2534 case elfcpp::R_386_TLS_LE_32:
2535 layout->set_has_static_tls();
2536 if (parameters->options().shared())
2538 // We need to create a dynamic relocation.
2539 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2540 ? elfcpp::R_386_TLS_TPOFF32
2541 : elfcpp::R_386_TLS_TPOFF);
2542 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2543 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2544 data_shndx, reloc.get_r_offset());
2554 case elfcpp::R_386_32PLT:
2555 case elfcpp::R_386_TLS_GD_32:
2556 case elfcpp::R_386_TLS_GD_PUSH:
2557 case elfcpp::R_386_TLS_GD_CALL:
2558 case elfcpp::R_386_TLS_GD_POP:
2559 case elfcpp::R_386_TLS_LDM_32:
2560 case elfcpp::R_386_TLS_LDM_PUSH:
2561 case elfcpp::R_386_TLS_LDM_CALL:
2562 case elfcpp::R_386_TLS_LDM_POP:
2563 case elfcpp::R_386_USED_BY_INTEL_200:
2565 unsupported_reloc_global(object, r_type, gsym);
2570 // Process relocations for gc.
2573 Target_i386::gc_process_relocs(Symbol_table* symtab,
2575 Sized_relobj_file<32, false>* object,
2576 unsigned int data_shndx,
2578 const unsigned char* prelocs,
2580 Output_section* output_section,
2581 bool needs_special_offset_handling,
2582 size_t local_symbol_count,
2583 const unsigned char* plocal_symbols)
2585 gold::gc_process_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2594 needs_special_offset_handling,
2599 // Scan relocations for a section.
2602 Target_i386::scan_relocs(Symbol_table* symtab,
2604 Sized_relobj_file<32, false>* object,
2605 unsigned int data_shndx,
2606 unsigned int sh_type,
2607 const unsigned char* prelocs,
2609 Output_section* output_section,
2610 bool needs_special_offset_handling,
2611 size_t local_symbol_count,
2612 const unsigned char* plocal_symbols)
2614 if (sh_type == elfcpp::SHT_RELA)
2616 gold_error(_("%s: unsupported RELA reloc section"),
2617 object->name().c_str());
2621 gold::scan_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2630 needs_special_offset_handling,
2635 // Finalize the sections.
2638 Target_i386::do_finalize_sections(
2640 const Input_objects*,
2641 Symbol_table* symtab)
2643 const Reloc_section* rel_plt = (this->plt_ == NULL
2645 : this->plt_->rel_plt());
2646 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2647 this->rel_dyn_, true, false);
2649 // Emit any relocs we saved in an attempt to avoid generating COPY
2651 if (this->copy_relocs_.any_saved_relocs())
2652 this->copy_relocs_.emit(this->rel_dyn_section(layout));
2654 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2655 // the .got.plt section.
2656 Symbol* sym = this->global_offset_table_;
2659 uint32_t data_size = this->got_plt_->current_data_size();
2660 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2663 if (parameters->doing_static_link()
2664 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2666 // If linking statically, make sure that the __rel_iplt symbols
2667 // were defined if necessary, even if we didn't create a PLT.
2668 static const Define_symbol_in_segment syms[] =
2671 "__rel_iplt_start", // name
2672 elfcpp::PT_LOAD, // segment_type
2673 elfcpp::PF_W, // segment_flags_set
2674 elfcpp::PF(0), // segment_flags_clear
2677 elfcpp::STT_NOTYPE, // type
2678 elfcpp::STB_GLOBAL, // binding
2679 elfcpp::STV_HIDDEN, // visibility
2681 Symbol::SEGMENT_START, // offset_from_base
2685 "__rel_iplt_end", // name
2686 elfcpp::PT_LOAD, // segment_type
2687 elfcpp::PF_W, // segment_flags_set
2688 elfcpp::PF(0), // segment_flags_clear
2691 elfcpp::STT_NOTYPE, // type
2692 elfcpp::STB_GLOBAL, // binding
2693 elfcpp::STV_HIDDEN, // visibility
2695 Symbol::SEGMENT_START, // offset_from_base
2700 symtab->define_symbols(layout, 2, syms,
2701 layout->script_options()->saw_sections_clause());
2705 // Return whether a direct absolute static relocation needs to be applied.
2706 // In cases where Scan::local() or Scan::global() has created
2707 // a dynamic relocation other than R_386_RELATIVE, the addend
2708 // of the relocation is carried in the data, and we must not
2709 // apply the static relocation.
2712 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2713 unsigned int r_type,
2715 Output_section* output_section)
2717 // If the output section is not allocated, then we didn't call
2718 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2720 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2723 int ref_flags = Scan::get_reference_flags(r_type);
2725 // For local symbols, we will have created a non-RELATIVE dynamic
2726 // relocation only if (a) the output is position independent,
2727 // (b) the relocation is absolute (not pc- or segment-relative), and
2728 // (c) the relocation is not 32 bits wide.
2730 return !(parameters->options().output_is_position_independent()
2731 && (ref_flags & Symbol::ABSOLUTE_REF)
2734 // For global symbols, we use the same helper routines used in the
2735 // scan pass. If we did not create a dynamic relocation, or if we
2736 // created a RELATIVE dynamic relocation, we should apply the static
2738 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2739 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2740 && gsym->can_use_relative_reloc(ref_flags
2741 & Symbol::FUNCTION_CALL);
2742 return !has_dyn || is_rel;
2745 // Perform a relocation.
2748 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2750 Target_i386* target,
2751 Output_section* output_section,
2753 const unsigned char* preloc,
2754 const Sized_symbol<32>* gsym,
2755 const Symbol_value<32>* psymval,
2756 unsigned char* view,
2757 elfcpp::Elf_types<32>::Elf_Addr address,
2758 section_size_type view_size)
2760 const elfcpp::Rel<32, false> rel(preloc);
2761 unsigned int r_type = elfcpp::elf_r_type<32>(rel.get_r_info());
2763 if (this->skip_call_tls_get_addr_)
2765 if ((r_type != elfcpp::R_386_PLT32
2766 && r_type != elfcpp::R_386_PC32)
2768 || strcmp(gsym->name(), "___tls_get_addr") != 0)
2769 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2770 _("missing expected TLS relocation"));
2773 this->skip_call_tls_get_addr_ = false;
2781 const Sized_relobj_file<32, false>* object = relinfo->object;
2783 // Pick the value to use for symbols defined in shared objects.
2784 Symbol_value<32> symval;
2786 && gsym->type() == elfcpp::STT_GNU_IFUNC
2787 && r_type == elfcpp::R_386_32
2788 && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2789 && gsym->can_use_relative_reloc(false)
2790 && !gsym->is_from_dynobj()
2791 && !gsym->is_undefined()
2792 && !gsym->is_preemptible())
2794 // In this case we are generating a R_386_IRELATIVE reloc. We
2795 // want to use the real value of the symbol, not the PLT offset.
2797 else if (gsym != NULL
2798 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2800 symval.set_output_value(target->plt_address_for_global(gsym));
2803 else if (gsym == NULL && psymval->is_ifunc_symbol())
2805 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2806 if (object->local_has_plt_offset(r_sym))
2808 symval.set_output_value(target->plt_address_for_local(object, r_sym));
2817 case elfcpp::R_386_NONE:
2818 case elfcpp::R_386_GNU_VTINHERIT:
2819 case elfcpp::R_386_GNU_VTENTRY:
2822 case elfcpp::R_386_32:
2823 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2824 Relocate_functions<32, false>::rel32(view, object, psymval);
2827 case elfcpp::R_386_PC32:
2828 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2829 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2832 case elfcpp::R_386_16:
2833 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2834 Relocate_functions<32, false>::rel16(view, object, psymval);
2837 case elfcpp::R_386_PC16:
2838 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2839 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2842 case elfcpp::R_386_8:
2843 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2844 Relocate_functions<32, false>::rel8(view, object, psymval);
2847 case elfcpp::R_386_PC8:
2848 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2849 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2852 case elfcpp::R_386_PLT32:
2853 gold_assert(gsym == NULL
2854 || gsym->has_plt_offset()
2855 || gsym->final_value_is_known()
2856 || (gsym->is_defined()
2857 && !gsym->is_from_dynobj()
2858 && !gsym->is_preemptible()));
2859 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2862 case elfcpp::R_386_GOT32:
2863 case elfcpp::R_386_GOT32X:
2864 baseless = (view[-1] & 0xc7) == 0x5;
2865 // R_386_GOT32 and R_386_GOT32X don't work without base register
2866 // when generating a position-independent output file.
2868 && parameters->options().output_is_position_independent())
2871 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2872 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2873 r_type, gsym->demangled_name().c_str());
2875 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2876 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2881 // mov foo@GOT(%reg), %reg
2883 // lea foo@GOTOFF(%reg), %reg
2885 if (rel.get_r_offset() >= 2
2887 && ((gsym == NULL && !psymval->is_ifunc_symbol())
2889 && Target_i386::can_convert_mov_to_lea(gsym))))
2892 elfcpp::Elf_types<32>::Elf_Addr value;
2893 value = psymval->value(object, 0);
2894 // Don't subtract the .got.plt section address for baseless
2897 value -= target->got_plt_section()->address();
2898 Relocate_functions<32, false>::rel32(view, value);
2902 // The GOT pointer points to the end of the GOT section.
2903 // We need to subtract the size of the GOT section to get
2904 // the actual offset to use in the relocation.
2905 unsigned int got_offset = 0;
2908 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2909 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2910 - target->got_size());
2914 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2915 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2916 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2917 - target->got_size());
2919 // Add the .got.plt section address for baseless addressing.
2921 got_offset += target->got_plt_section()->address();
2922 Relocate_functions<32, false>::rel32(view, got_offset);
2926 case elfcpp::R_386_GOTOFF:
2928 elfcpp::Elf_types<32>::Elf_Addr value;
2929 value = (psymval->value(object, 0)
2930 - target->got_plt_section()->address());
2931 Relocate_functions<32, false>::rel32(view, value);
2935 case elfcpp::R_386_GOTPC:
2937 elfcpp::Elf_types<32>::Elf_Addr value;
2938 value = target->got_plt_section()->address();
2939 Relocate_functions<32, false>::pcrel32(view, value, address);
2943 case elfcpp::R_386_COPY:
2944 case elfcpp::R_386_GLOB_DAT:
2945 case elfcpp::R_386_JUMP_SLOT:
2946 case elfcpp::R_386_RELATIVE:
2947 case elfcpp::R_386_IRELATIVE:
2948 // These are outstanding tls relocs, which are unexpected when
2950 case elfcpp::R_386_TLS_TPOFF:
2951 case elfcpp::R_386_TLS_DTPMOD32:
2952 case elfcpp::R_386_TLS_DTPOFF32:
2953 case elfcpp::R_386_TLS_TPOFF32:
2954 case elfcpp::R_386_TLS_DESC:
2955 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2956 _("unexpected reloc %u in object file"),
2960 // These are initial tls relocs, which are expected when
2962 case elfcpp::R_386_TLS_GD: // Global-dynamic
2963 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2964 case elfcpp::R_386_TLS_DESC_CALL:
2965 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2966 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2967 case elfcpp::R_386_TLS_IE: // Initial-exec
2968 case elfcpp::R_386_TLS_IE_32:
2969 case elfcpp::R_386_TLS_GOTIE:
2970 case elfcpp::R_386_TLS_LE: // Local-exec
2971 case elfcpp::R_386_TLS_LE_32:
2972 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2973 view, address, view_size);
2976 case elfcpp::R_386_32PLT:
2977 case elfcpp::R_386_TLS_GD_32:
2978 case elfcpp::R_386_TLS_GD_PUSH:
2979 case elfcpp::R_386_TLS_GD_CALL:
2980 case elfcpp::R_386_TLS_GD_POP:
2981 case elfcpp::R_386_TLS_LDM_32:
2982 case elfcpp::R_386_TLS_LDM_PUSH:
2983 case elfcpp::R_386_TLS_LDM_CALL:
2984 case elfcpp::R_386_TLS_LDM_POP:
2985 case elfcpp::R_386_USED_BY_INTEL_200:
2987 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2988 _("unsupported reloc %u"),
2996 // Perform a TLS relocation.
2999 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
3000 Target_i386* target,
3002 const elfcpp::Rel<32, false>& rel,
3003 unsigned int r_type,
3004 const Sized_symbol<32>* gsym,
3005 const Symbol_value<32>* psymval,
3006 unsigned char* view,
3007 elfcpp::Elf_types<32>::Elf_Addr,
3008 section_size_type view_size)
3010 Output_segment* tls_segment = relinfo->layout->tls_segment();
3012 const Sized_relobj_file<32, false>* object = relinfo->object;
3014 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
3016 const bool is_final = (gsym == NULL
3017 ? !parameters->options().shared()
3018 : gsym->final_value_is_known());
3019 const tls::Tls_optimization optimized_type
3020 = Target_i386::optimize_tls_reloc(is_final, r_type);
3023 case elfcpp::R_386_TLS_GD: // Global-dynamic
3024 if (optimized_type == tls::TLSOPT_TO_LE)
3026 if (tls_segment == NULL)
3028 gold_assert(parameters->errors()->error_count() > 0
3029 || issue_undefined_symbol_error(gsym));
3032 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3033 rel, r_type, value, view,
3039 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3040 ? GOT_TYPE_TLS_NOFFSET
3041 : GOT_TYPE_TLS_PAIR);
3042 unsigned int got_offset;
3045 gold_assert(gsym->has_got_offset(got_type));
3046 got_offset = gsym->got_offset(got_type) - target->got_size();
3050 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3051 gold_assert(object->local_has_got_offset(r_sym, got_type));
3052 got_offset = (object->local_got_offset(r_sym, got_type)
3053 - target->got_size());
3055 if (optimized_type == tls::TLSOPT_TO_IE)
3057 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
3058 got_offset, view, view_size);
3061 else if (optimized_type == tls::TLSOPT_NONE)
3063 // Relocate the field with the offset of the pair of GOT
3065 Relocate_functions<32, false>::rel32(view, got_offset);
3069 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3070 _("unsupported reloc %u"),
3074 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3075 case elfcpp::R_386_TLS_DESC_CALL:
3076 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3077 if (optimized_type == tls::TLSOPT_TO_LE)
3079 if (tls_segment == NULL)
3081 gold_assert(parameters->errors()->error_count() > 0
3082 || issue_undefined_symbol_error(gsym));
3085 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3086 rel, r_type, value, view,
3092 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3093 ? GOT_TYPE_TLS_NOFFSET
3094 : GOT_TYPE_TLS_DESC);
3095 unsigned int got_offset = 0;
3096 if (r_type == elfcpp::R_386_TLS_GOTDESC
3097 && optimized_type == tls::TLSOPT_NONE)
3099 // We created GOT entries in the .got.tlsdesc portion of
3100 // the .got.plt section, but the offset stored in the
3101 // symbol is the offset within .got.tlsdesc.
3102 got_offset = (target->got_size()
3103 + target->got_plt_section()->data_size());
3107 gold_assert(gsym->has_got_offset(got_type));
3108 got_offset += gsym->got_offset(got_type) - target->got_size();
3112 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3113 gold_assert(object->local_has_got_offset(r_sym, got_type));
3114 got_offset += (object->local_got_offset(r_sym, got_type)
3115 - target->got_size());
3117 if (optimized_type == tls::TLSOPT_TO_IE)
3119 if (tls_segment == NULL)
3121 gold_assert(parameters->errors()->error_count() > 0
3122 || issue_undefined_symbol_error(gsym));
3125 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
3126 got_offset, view, view_size);
3129 else if (optimized_type == tls::TLSOPT_NONE)
3131 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3133 // Relocate the field with the offset of the pair of GOT
3135 Relocate_functions<32, false>::rel32(view, got_offset);
3140 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3141 _("unsupported reloc %u"),
3145 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3146 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
3148 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3149 _("both SUN and GNU model "
3150 "TLS relocations"));
3153 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3154 if (optimized_type == tls::TLSOPT_TO_LE)
3156 if (tls_segment == NULL)
3158 gold_assert(parameters->errors()->error_count() > 0
3159 || issue_undefined_symbol_error(gsym));
3162 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
3163 value, view, view_size);
3166 else if (optimized_type == tls::TLSOPT_NONE)
3168 // Relocate the field with the offset of the GOT entry for
3169 // the module index.
3170 unsigned int got_offset;
3171 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3172 - target->got_size());
3173 Relocate_functions<32, false>::rel32(view, got_offset);
3176 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3177 _("unsupported reloc %u"),
3181 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3182 if (optimized_type == tls::TLSOPT_TO_LE)
3184 // This reloc can appear in debugging sections, in which
3185 // case we must not convert to local-exec. We decide what
3186 // to do based on whether the section is marked as
3187 // containing executable code. That is what the GNU linker
3189 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
3190 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
3192 if (tls_segment == NULL)
3194 gold_assert(parameters->errors()->error_count() > 0
3195 || issue_undefined_symbol_error(gsym));
3198 value -= tls_segment->memsz();
3201 Relocate_functions<32, false>::rel32(view, value);
3204 case elfcpp::R_386_TLS_IE: // Initial-exec
3205 case elfcpp::R_386_TLS_GOTIE:
3206 case elfcpp::R_386_TLS_IE_32:
3207 if (optimized_type == tls::TLSOPT_TO_LE)
3209 if (tls_segment == NULL)
3211 gold_assert(parameters->errors()->error_count() > 0
3212 || issue_undefined_symbol_error(gsym));
3215 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3216 rel, r_type, value, view,
3220 else if (optimized_type == tls::TLSOPT_NONE)
3222 // Relocate the field with the offset of the GOT entry for
3223 // the tp-relative offset of the symbol.
3224 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
3225 ? GOT_TYPE_TLS_OFFSET
3226 : GOT_TYPE_TLS_NOFFSET);
3227 unsigned int got_offset;
3230 gold_assert(gsym->has_got_offset(got_type));
3231 got_offset = gsym->got_offset(got_type);
3235 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3236 gold_assert(object->local_has_got_offset(r_sym, got_type));
3237 got_offset = object->local_got_offset(r_sym, got_type);
3239 // For the R_386_TLS_IE relocation, we need to apply the
3240 // absolute address of the GOT entry.
3241 if (r_type == elfcpp::R_386_TLS_IE)
3242 got_offset += target->got_plt_section()->address();
3243 // All GOT offsets are relative to the end of the GOT.
3244 got_offset -= target->got_size();
3245 Relocate_functions<32, false>::rel32(view, got_offset);
3248 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3249 _("unsupported reloc %u"),
3253 case elfcpp::R_386_TLS_LE: // Local-exec
3254 // If we're creating a shared library, a dynamic relocation will
3255 // have been created for this location, so do not apply it now.
3256 if (!parameters->options().shared())
3258 if (tls_segment == NULL)
3260 gold_assert(parameters->errors()->error_count() > 0
3261 || issue_undefined_symbol_error(gsym));
3264 value -= tls_segment->memsz();
3265 Relocate_functions<32, false>::rel32(view, value);
3269 case elfcpp::R_386_TLS_LE_32:
3270 // If we're creating a shared library, a dynamic relocation will
3271 // have been created for this location, so do not apply it now.
3272 if (!parameters->options().shared())
3274 if (tls_segment == NULL)
3276 gold_assert(parameters->errors()->error_count() > 0
3277 || issue_undefined_symbol_error(gsym));
3280 value = tls_segment->memsz() - value;
3281 Relocate_functions<32, false>::rel32(view, value);
3287 // Do a relocation in which we convert a TLS General-Dynamic to a
3291 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
3293 Output_segment* tls_segment,
3294 const elfcpp::Rel<32, false>& rel,
3296 elfcpp::Elf_types<32>::Elf_Addr value,
3297 unsigned char* view,
3298 section_size_type view_size)
3300 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3301 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3302 // leal foo(%reg),%eax; call ___tls_get_addr
3303 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3305 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3306 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3308 unsigned char op1 = view[-1];
3309 unsigned char op2 = view[-2];
3311 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3312 op2 == 0x8d || op2 == 0x04);
3313 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3319 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3320 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3321 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3322 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3323 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3327 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3328 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3329 if (rel.get_r_offset() + 9 < view_size
3332 // There is a trailing nop. Use the size byte subl.
3333 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3338 // Use the five byte subl.
3339 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3343 value = tls_segment->memsz() - value;
3344 Relocate_functions<32, false>::rel32(view + roff, value);
3346 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3348 this->skip_call_tls_get_addr_ = true;
3351 // Do a relocation in which we convert a TLS General-Dynamic to an
3355 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3358 const elfcpp::Rel<32, false>& rel,
3360 elfcpp::Elf_types<32>::Elf_Addr value,
3361 unsigned char* view,
3362 section_size_type view_size)
3364 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3365 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3366 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3367 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3369 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3370 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3372 unsigned char op1 = view[-1];
3373 unsigned char op2 = view[-2];
3375 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3376 op2 == 0x8d || op2 == 0x04);
3377 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3383 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3384 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3385 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3386 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3391 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
3392 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3393 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3394 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[9] == 0x90);
3398 memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3399 Relocate_functions<32, false>::rel32(view + roff, value);
3401 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3403 this->skip_call_tls_get_addr_ = true;
3406 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3407 // General-Dynamic to a Local-Exec.
3410 Target_i386::Relocate::tls_desc_gd_to_le(
3411 const Relocate_info<32, false>* relinfo,
3413 Output_segment* tls_segment,
3414 const elfcpp::Rel<32, false>& rel,
3415 unsigned int r_type,
3416 elfcpp::Elf_types<32>::Elf_Addr value,
3417 unsigned char* view,
3418 section_size_type view_size)
3420 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3422 // leal foo@TLSDESC(%ebx), %eax
3423 // ==> leal foo@NTPOFF, %eax
3424 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3425 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3426 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3427 view[-2] == 0x8d && view[-1] == 0x83);
3429 value -= tls_segment->memsz();
3430 Relocate_functions<32, false>::rel32(view, value);
3434 // call *foo@TLSCALL(%eax)
3436 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3437 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3438 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3439 view[0] == 0xff && view[1] == 0x10);
3445 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3446 // General-Dynamic to an Initial-Exec.
3449 Target_i386::Relocate::tls_desc_gd_to_ie(
3450 const Relocate_info<32, false>* relinfo,
3453 const elfcpp::Rel<32, false>& rel,
3454 unsigned int r_type,
3455 elfcpp::Elf_types<32>::Elf_Addr value,
3456 unsigned char* view,
3457 section_size_type view_size)
3459 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3461 // leal foo@TLSDESC(%ebx), %eax
3462 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3463 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3464 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3465 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3466 view[-2] == 0x8d && view[-1] == 0x83);
3468 Relocate_functions<32, false>::rel32(view, value);
3472 // call *foo@TLSCALL(%eax)
3474 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3475 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3476 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3477 view[0] == 0xff && view[1] == 0x10);
3483 // Do a relocation in which we convert a TLS Local-Dynamic to a
3487 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3490 const elfcpp::Rel<32, false>& rel,
3492 elfcpp::Elf_types<32>::Elf_Addr,
3493 unsigned char* view,
3494 section_size_type view_size)
3496 // leal foo(%reg), %eax; call ___tls_get_addr
3497 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3499 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3500 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3502 // FIXME: Does this test really always pass?
3503 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3504 view[-2] == 0x8d && view[-1] == 0x83);
3506 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3508 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3510 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3512 this->skip_call_tls_get_addr_ = true;
3515 // Do a relocation in which we convert a TLS Initial-Exec to a
3519 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3521 Output_segment* tls_segment,
3522 const elfcpp::Rel<32, false>& rel,
3523 unsigned int r_type,
3524 elfcpp::Elf_types<32>::Elf_Addr value,
3525 unsigned char* view,
3526 section_size_type view_size)
3528 // We have to actually change the instructions, which means that we
3529 // need to examine the opcodes to figure out which instruction we
3531 if (r_type == elfcpp::R_386_TLS_IE)
3533 // movl %gs:XX,%eax ==> movl $YY,%eax
3534 // movl %gs:XX,%reg ==> movl $YY,%reg
3535 // addl %gs:XX,%reg ==> addl $YY,%reg
3536 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3537 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3539 unsigned char op1 = view[-1];
3542 // movl XX,%eax ==> movl $YY,%eax
3547 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3549 unsigned char op2 = view[-2];
3552 // movl XX,%reg ==> movl $YY,%reg
3553 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3554 (op1 & 0xc7) == 0x05);
3556 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3558 else if (op2 == 0x03)
3560 // addl XX,%reg ==> addl $YY,%reg
3561 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3562 (op1 & 0xc7) == 0x05);
3564 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3567 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3572 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3573 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3574 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3575 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3576 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3578 unsigned char op1 = view[-1];
3579 unsigned char op2 = view[-2];
3580 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3581 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3584 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3586 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3588 else if (op2 == 0x2b)
3590 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3592 view[-1] = 0xe8 | ((op1 >> 3) & 7);
3594 else if (op2 == 0x03)
3596 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3598 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3601 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3604 value = tls_segment->memsz() - value;
3605 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3608 Relocate_functions<32, false>::rel32(view, value);
3611 // Relocate section data.
3614 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3615 unsigned int sh_type,
3616 const unsigned char* prelocs,
3618 Output_section* output_section,
3619 bool needs_special_offset_handling,
3620 unsigned char* view,
3621 elfcpp::Elf_types<32>::Elf_Addr address,
3622 section_size_type view_size,
3623 const Reloc_symbol_changes* reloc_symbol_changes)
3625 gold_assert(sh_type == elfcpp::SHT_REL);
3627 gold::relocate_section<32, false, Target_i386, Relocate,
3628 gold::Default_comdat_behavior, Classify_reloc>(
3634 needs_special_offset_handling,
3638 reloc_symbol_changes);
3641 // Return the size of a relocation while scanning during a relocatable
3645 Target_i386::Classify_reloc::get_size_for_reloc(
3646 unsigned int r_type,
3651 case elfcpp::R_386_NONE:
3652 case elfcpp::R_386_GNU_VTINHERIT:
3653 case elfcpp::R_386_GNU_VTENTRY:
3654 case elfcpp::R_386_TLS_GD: // Global-dynamic
3655 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3656 case elfcpp::R_386_TLS_DESC_CALL:
3657 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3658 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3659 case elfcpp::R_386_TLS_IE: // Initial-exec
3660 case elfcpp::R_386_TLS_IE_32:
3661 case elfcpp::R_386_TLS_GOTIE:
3662 case elfcpp::R_386_TLS_LE: // Local-exec
3663 case elfcpp::R_386_TLS_LE_32:
3666 case elfcpp::R_386_32:
3667 case elfcpp::R_386_PC32:
3668 case elfcpp::R_386_GOT32:
3669 case elfcpp::R_386_GOT32X:
3670 case elfcpp::R_386_PLT32:
3671 case elfcpp::R_386_GOTOFF:
3672 case elfcpp::R_386_GOTPC:
3675 case elfcpp::R_386_16:
3676 case elfcpp::R_386_PC16:
3679 case elfcpp::R_386_8:
3680 case elfcpp::R_386_PC8:
3683 // These are relocations which should only be seen by the
3684 // dynamic linker, and should never be seen here.
3685 case elfcpp::R_386_COPY:
3686 case elfcpp::R_386_GLOB_DAT:
3687 case elfcpp::R_386_JUMP_SLOT:
3688 case elfcpp::R_386_RELATIVE:
3689 case elfcpp::R_386_IRELATIVE:
3690 case elfcpp::R_386_TLS_TPOFF:
3691 case elfcpp::R_386_TLS_DTPMOD32:
3692 case elfcpp::R_386_TLS_DTPOFF32:
3693 case elfcpp::R_386_TLS_TPOFF32:
3694 case elfcpp::R_386_TLS_DESC:
3695 object->error(_("unexpected reloc %u in object file"), r_type);
3698 case elfcpp::R_386_32PLT:
3699 case elfcpp::R_386_TLS_GD_32:
3700 case elfcpp::R_386_TLS_GD_PUSH:
3701 case elfcpp::R_386_TLS_GD_CALL:
3702 case elfcpp::R_386_TLS_GD_POP:
3703 case elfcpp::R_386_TLS_LDM_32:
3704 case elfcpp::R_386_TLS_LDM_PUSH:
3705 case elfcpp::R_386_TLS_LDM_CALL:
3706 case elfcpp::R_386_TLS_LDM_POP:
3707 case elfcpp::R_386_USED_BY_INTEL_200:
3709 object->error(_("unsupported reloc %u in object file"), r_type);
3714 // Scan the relocs during a relocatable link.
3717 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3719 Sized_relobj_file<32, false>* object,
3720 unsigned int data_shndx,
3721 unsigned int sh_type,
3722 const unsigned char* prelocs,
3724 Output_section* output_section,
3725 bool needs_special_offset_handling,
3726 size_t local_symbol_count,
3727 const unsigned char* plocal_symbols,
3728 Relocatable_relocs* rr)
3730 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
3731 Scan_relocatable_relocs;
3733 gold_assert(sh_type == elfcpp::SHT_REL);
3735 gold::scan_relocatable_relocs<32, false, Scan_relocatable_relocs>(
3743 needs_special_offset_handling,
3749 // Scan the relocs for --emit-relocs.
3752 Target_i386::emit_relocs_scan(Symbol_table* symtab,
3754 Sized_relobj_file<32, false>* object,
3755 unsigned int data_shndx,
3756 unsigned int sh_type,
3757 const unsigned char* prelocs,
3759 Output_section* output_section,
3760 bool needs_special_offset_handling,
3761 size_t local_symbol_count,
3762 const unsigned char* plocal_syms,
3763 Relocatable_relocs* rr)
3765 typedef gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
3767 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
3768 Emit_relocs_strategy;
3770 gold_assert(sh_type == elfcpp::SHT_REL);
3772 gold::scan_relocatable_relocs<32, false, Emit_relocs_strategy>(
3780 needs_special_offset_handling,
3786 // Emit relocations for a section.
3789 Target_i386::relocate_relocs(
3790 const Relocate_info<32, false>* relinfo,
3791 unsigned int sh_type,
3792 const unsigned char* prelocs,
3794 Output_section* output_section,
3795 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
3796 unsigned char* view,
3797 elfcpp::Elf_types<32>::Elf_Addr view_address,
3798 section_size_type view_size,
3799 unsigned char* reloc_view,
3800 section_size_type reloc_view_size)
3802 gold_assert(sh_type == elfcpp::SHT_REL);
3804 gold::relocate_relocs<32, false, Classify_reloc>(
3809 offset_in_output_section,
3817 // Return the value to use for a dynamic which requires special
3818 // treatment. This is how we support equality comparisons of function
3819 // pointers across shared library boundaries, as described in the
3820 // processor specific ABI supplement.
3823 Target_i386::do_dynsym_value(const Symbol* gsym) const
3825 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3826 return this->plt_address_for_global(gsym);
3829 // Return a string used to fill a code section with nops to take up
3830 // the specified length.
3833 Target_i386::do_code_fill(section_size_type length) const
3837 // Build a jmp instruction to skip over the bytes.
3838 unsigned char jmp[5];
3840 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3841 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3842 + std::string(length - 5, static_cast<char>(0x90)));
3845 // Nop sequences of various lengths.
3846 const char nop1[1] = { '\x90' }; // nop
3847 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
3848 const char nop3[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3849 const char nop4[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3851 const char nop5[5] = { '\x90', '\x8d', '\x74', // nop
3852 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3853 const char nop6[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3854 '\x00', '\x00', '\x00' };
3855 const char nop7[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3856 '\x00', '\x00', '\x00',
3858 const char nop8[8] = { '\x90', '\x8d', '\xb4', // nop
3859 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3861 const char nop9[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3862 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3863 '\x00', '\x00', '\x00' };
3864 const char nop10[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3865 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3866 '\x00', '\x00', '\x00',
3868 const char nop11[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3869 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3870 '\x27', '\x00', '\x00',
3872 const char nop12[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3873 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3874 '\x8d', '\xbf', '\x00',
3875 '\x00', '\x00', '\x00' };
3876 const char nop13[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3877 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3878 '\x8d', '\xbc', '\x27',
3879 '\x00', '\x00', '\x00',
3881 const char nop14[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3882 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3883 '\x00', '\x8d', '\xbc',
3884 '\x27', '\x00', '\x00',
3886 const char nop15[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3887 '\x90', '\x90', '\x90', // nop,nop,nop,...
3888 '\x90', '\x90', '\x90',
3889 '\x90', '\x90', '\x90',
3890 '\x90', '\x90', '\x90' };
3892 const char* nops[16] = {
3894 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3895 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3898 return std::string(nops[length], length);
3901 // Return the value to use for the base of a DW_EH_PE_datarel offset
3902 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3903 // assembler can not write out the difference between two labels in
3904 // different sections, so instead of using a pc-relative value they
3905 // use an offset from the GOT.
3908 Target_i386::do_ehframe_datarel_base() const
3910 gold_assert(this->global_offset_table_ != NULL);
3911 Symbol* sym = this->global_offset_table_;
3912 Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3913 return ssym->value();
3916 // Return whether SYM should be treated as a call to a non-split
3917 // function. We don't want that to be true of a call to a
3918 // get_pc_thunk function.
3921 Target_i386::do_is_call_to_non_split(const Symbol* sym,
3922 const unsigned char*) const
3924 return (sym->type() == elfcpp::STT_FUNC
3925 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3928 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3929 // compiled with -fsplit-stack. The function calls non-split-stack
3930 // code. We have to change the function so that it always ensures
3931 // that it has enough stack space to run some random function.
3934 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3935 section_offset_type fnoffset,
3936 section_size_type fnsize,
3937 const unsigned char*,
3939 unsigned char* view,
3940 section_size_type view_size,
3942 std::string* to) const
3944 // The function starts with a comparison of the stack pointer and a
3945 // field in the TCB. This is followed by a jump.
3948 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3951 // We will call __morestack if the carry flag is set after this
3952 // comparison. We turn the comparison into an stc instruction
3954 view[fnoffset] = '\xf9';
3955 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3957 // lea NN(%esp),%ecx
3958 // lea NN(%esp),%edx
3959 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3960 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3963 // This is loading an offset from the stack pointer for a
3964 // comparison. The offset is negative, so we decrease the
3965 // offset by the amount of space we need for the stack. This
3966 // means we will avoid calling __morestack if there happens to
3967 // be plenty of space on the stack already.
3968 unsigned char* pval = view + fnoffset + 3;
3969 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3970 val -= parameters->options().split_stack_adjust_size();
3971 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3975 if (!object->has_no_split_stack())
3976 object->error(_("failed to match split-stack sequence at "
3977 "section %u offset %0zx"),
3978 shndx, static_cast<size_t>(fnoffset));
3982 // We have to change the function so that it calls
3983 // __morestack_non_split instead of __morestack. The former will
3984 // allocate additional stack space.
3985 *from = "__morestack";
3986 *to = "__morestack_non_split";
3989 // The selector for i386 object files. Note this is never instantiated
3990 // directly. It's only used in Target_selector_i386_nacl, below.
3992 class Target_selector_i386 : public Target_selector_freebsd
3995 Target_selector_i386()
3996 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3997 "elf32-i386", "elf32-i386-freebsd",
4002 do_instantiate_target()
4003 { return new Target_i386(); }
4006 // NaCl variant. It uses different PLT contents.
4008 class Output_data_plt_i386_nacl : public Output_data_plt_i386
4011 Output_data_plt_i386_nacl(Layout* layout,
4012 Output_data_got_plt_i386* got_plt,
4013 Output_data_space* got_irelative)
4014 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
4018 virtual unsigned int
4019 do_get_plt_entry_size() const
4020 { return plt_entry_size; }
4023 do_add_eh_frame(Layout* layout)
4025 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
4026 plt_eh_frame_fde, plt_eh_frame_fde_size);
4029 // The size of an entry in the PLT.
4030 static const int plt_entry_size = 64;
4032 // The .eh_frame unwind information for the PLT.
4033 static const int plt_eh_frame_fde_size = 32;
4034 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4037 class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
4040 Output_data_plt_i386_nacl_exec(Layout* layout,
4041 Output_data_got_plt_i386* got_plt,
4042 Output_data_space* got_irelative)
4043 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4048 do_fill_first_plt_entry(unsigned char* pov,
4049 elfcpp::Elf_types<32>::Elf_Addr got_address);
4051 virtual unsigned int
4052 do_fill_plt_entry(unsigned char* pov,
4053 elfcpp::Elf_types<32>::Elf_Addr got_address,
4054 unsigned int got_offset,
4055 unsigned int plt_offset,
4056 unsigned int plt_rel_offset);
4059 // The first entry in the PLT for an executable.
4060 static const unsigned char first_plt_entry[plt_entry_size];
4062 // Other entries in the PLT for an executable.
4063 static const unsigned char plt_entry[plt_entry_size];
4066 class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
4069 Output_data_plt_i386_nacl_dyn(Layout* layout,
4070 Output_data_got_plt_i386* got_plt,
4071 Output_data_space* got_irelative)
4072 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4077 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
4079 virtual unsigned int
4080 do_fill_plt_entry(unsigned char* pov,
4081 elfcpp::Elf_types<32>::Elf_Addr,
4082 unsigned int got_offset,
4083 unsigned int plt_offset,
4084 unsigned int plt_rel_offset);
4087 // The first entry in the PLT for a shared object.
4088 static const unsigned char first_plt_entry[plt_entry_size];
4090 // Other entries in the PLT for a shared object.
4091 static const unsigned char plt_entry[plt_entry_size];
4094 class Target_i386_nacl : public Target_i386
4098 : Target_i386(&i386_nacl_info)
4102 virtual Output_data_plt_i386*
4103 do_make_data_plt(Layout* layout,
4104 Output_data_got_plt_i386* got_plt,
4105 Output_data_space* got_irelative,
4109 return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
4111 return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
4115 do_code_fill(section_size_type length) const;
4118 static const Target::Target_info i386_nacl_info;
4121 const Target::Target_info Target_i386_nacl::i386_nacl_info =
4124 false, // is_big_endian
4125 elfcpp::EM_386, // machine_code
4126 false, // has_make_symbol
4127 false, // has_resolve
4128 true, // has_code_fill
4129 true, // is_default_stack_executable
4130 true, // can_icf_inline_merge_sections
4132 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4133 0x20000, // default_text_segment_address
4134 0x10000, // abi_pagesize (overridable by -z max-page-size)
4135 0x10000, // common_pagesize (overridable by -z common-page-size)
4136 true, // isolate_execinstr
4137 0x10000000, // rosegment_gap
4138 elfcpp::SHN_UNDEF, // small_common_shndx
4139 elfcpp::SHN_UNDEF, // large_common_shndx
4140 0, // small_common_section_flags
4141 0, // large_common_section_flags
4142 NULL, // attributes_section
4143 NULL, // attributes_vendor
4144 "_start", // entry_symbol_name
4145 32, // hash_entry_size
4148 #define NACLMASK 0xe0 // 32-byte alignment mask
4151 Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
4153 0xff, 0x35, // pushl contents of memory address
4154 0, 0, 0, 0, // replaced with address of .got + 4
4155 0x8b, 0x0d, // movl contents of address, %ecx
4156 0, 0, 0, 0, // replaced with address of .got + 8
4157 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4158 0xff, 0xe1, // jmp *%ecx
4159 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4160 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4161 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4162 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4163 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4164 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4165 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4166 0x90, 0x90, 0x90, 0x90, 0x90
4170 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4172 elfcpp::Elf_types<32>::Elf_Addr got_address)
4174 memcpy(pov, first_plt_entry, plt_entry_size);
4175 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
4176 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
4179 // The first entry in the PLT for a shared object.
4182 Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
4184 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4185 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4186 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4187 0xff, 0xe1, // jmp *%ecx
4188 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4189 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4190 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4191 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4192 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4193 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4194 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4195 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4196 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4197 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4201 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4203 elfcpp::Elf_types<32>::Elf_Addr)
4205 memcpy(pov, first_plt_entry, plt_entry_size);
4208 // Subsequent entries in the PLT for an executable.
4211 Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
4213 0x8b, 0x0d, // movl contents of address, %ecx */
4214 0, 0, 0, 0, // replaced with address of symbol in .got
4215 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4216 0xff, 0xe1, // jmp *%ecx
4218 // Pad to the next 32-byte boundary with nop instructions.
4220 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4221 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4223 // Lazy GOT entries point here (32-byte aligned).
4224 0x68, // pushl immediate
4225 0, 0, 0, 0, // replaced with offset into relocation table
4226 0xe9, // jmp relative
4227 0, 0, 0, 0, // replaced with offset to start of .plt
4229 // Pad to the next 32-byte boundary with nop instructions.
4230 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4231 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4236 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4238 elfcpp::Elf_types<32>::Elf_Addr got_address,
4239 unsigned int got_offset,
4240 unsigned int plt_offset,
4241 unsigned int plt_rel_offset)
4243 memcpy(pov, plt_entry, plt_entry_size);
4244 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4245 got_address + got_offset);
4246 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4247 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4251 // Subsequent entries in the PLT for a shared object.
4254 Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
4256 0x8b, 0x8b, // movl offset(%ebx), %ecx
4257 0, 0, 0, 0, // replaced with offset of symbol in .got
4258 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4259 0xff, 0xe1, // jmp *%ecx
4261 // Pad to the next 32-byte boundary with nop instructions.
4263 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4264 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4266 // Lazy GOT entries point here (32-byte aligned).
4267 0x68, // pushl immediate
4268 0, 0, 0, 0, // replaced with offset into relocation table.
4269 0xe9, // jmp relative
4270 0, 0, 0, 0, // replaced with offset to start of .plt.
4272 // Pad to the next 32-byte boundary with nop instructions.
4273 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4274 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4279 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4281 elfcpp::Elf_types<32>::Elf_Addr,
4282 unsigned int got_offset,
4283 unsigned int plt_offset,
4284 unsigned int plt_rel_offset)
4286 memcpy(pov, plt_entry, plt_entry_size);
4287 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
4288 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4289 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4294 Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4296 0, 0, 0, 0, // Replaced with offset to .plt.
4297 0, 0, 0, 0, // Replaced with size of .plt.
4298 0, // Augmentation size.
4299 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
4300 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4301 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
4302 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4303 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4304 13, // Block length.
4305 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
4306 elfcpp::DW_OP_breg8, 0, // Push %eip.
4307 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4308 elfcpp::DW_OP_and, // & (%eip & 0x3f).
4309 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4310 elfcpp::DW_OP_ge, // >= ((%eip & 0x3f) >= 0x25)
4311 elfcpp::DW_OP_lit2, // Push 2.
4312 elfcpp::DW_OP_shl, // << (((%eip & 0x3f) >= 0x25) << 2)
4313 elfcpp::DW_OP_plus, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4314 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4318 // Return a string used to fill a code section with nops.
4319 // For NaCl, long NOPs are only valid if they do not cross
4320 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4322 Target_i386_nacl::do_code_fill(section_size_type length) const
4324 return std::string(length, static_cast<char>(0x90));
4327 // The selector for i386-nacl object files.
4329 class Target_selector_i386_nacl
4330 : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
4333 Target_selector_i386_nacl()
4334 : Target_selector_nacl<Target_selector_i386,
4335 Target_i386_nacl>("x86-32",
4341 Target_selector_i386_nacl target_selector_i386;
4343 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4345 class Target_iamcu : public Target_i386
4349 : Target_i386(&iamcu_info)
4353 // Information about this specific target which we pass to the
4354 // general Target structure.
4355 static const Target::Target_info iamcu_info;
4358 const Target::Target_info Target_iamcu::iamcu_info =
4361 false, // is_big_endian
4362 elfcpp::EM_IAMCU, // machine_code
4363 false, // has_make_symbol
4364 false, // has_resolve
4365 true, // has_code_fill
4366 true, // is_default_stack_executable
4367 true, // can_icf_inline_merge_sections
4369 "/usr/lib/libc.so.1", // dynamic_linker
4370 0x08048000, // default_text_segment_address
4371 0x1000, // abi_pagesize (overridable by -z max-page-size)
4372 0x1000, // common_pagesize (overridable by -z common-page-size)
4373 false, // isolate_execinstr
4375 elfcpp::SHN_UNDEF, // small_common_shndx
4376 elfcpp::SHN_UNDEF, // large_common_shndx
4377 0, // small_common_section_flags
4378 0, // large_common_section_flags
4379 NULL, // attributes_section
4380 NULL, // attributes_vendor
4381 "_start", // entry_symbol_name
4382 32, // hash_entry_size
4385 class Target_selector_iamcu : public Target_selector
4388 Target_selector_iamcu()
4389 : Target_selector(elfcpp::EM_IAMCU, 32, false, "elf32-iamcu",
4394 do_instantiate_target()
4395 { return new Target_iamcu(); }
4398 Target_selector_iamcu target_selector_iamcu;
4400 } // End anonymous namespace.