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 const elfcpp::Rel<32, false>&, unsigned int r_type,
672 elfcpp::Elf_types<32>::Elf_Addr value,
674 section_size_type view_size);
676 // Do a TLS General-Dynamic to Local-Exec transition.
678 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
679 Output_segment* tls_segment,
680 const elfcpp::Rel<32, false>&, unsigned int r_type,
681 elfcpp::Elf_types<32>::Elf_Addr value,
683 section_size_type view_size);
685 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
688 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
689 const elfcpp::Rel<32, false>&, unsigned int r_type,
690 elfcpp::Elf_types<32>::Elf_Addr value,
692 section_size_type view_size);
694 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
697 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
698 Output_segment* tls_segment,
699 const elfcpp::Rel<32, false>&, unsigned int r_type,
700 elfcpp::Elf_types<32>::Elf_Addr value,
702 section_size_type view_size);
704 // Do a TLS Local-Dynamic to Local-Exec transition.
706 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
707 Output_segment* tls_segment,
708 const elfcpp::Rel<32, false>&, unsigned int r_type,
709 elfcpp::Elf_types<32>::Elf_Addr value,
711 section_size_type view_size);
713 // Do a TLS Initial-Exec to Local-Exec transition.
715 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
716 Output_segment* tls_segment,
717 const elfcpp::Rel<32, false>&, unsigned int r_type,
718 elfcpp::Elf_types<32>::Elf_Addr value,
720 section_size_type view_size);
722 // We need to keep track of which type of local dynamic relocation
723 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
724 enum Local_dynamic_type
731 // This is set if we should skip the next reloc, which should be a
732 // PLT32 reloc against ___tls_get_addr.
733 bool skip_call_tls_get_addr_;
734 // The type of local dynamic relocation we have seen in the section
735 // being relocated, if any.
736 Local_dynamic_type local_dynamic_type_;
739 // A class for inquiring about properties of a relocation,
740 // used while scanning relocs during a relocatable link and
741 // garbage collection.
742 class Classify_reloc :
743 public gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
746 // Return the size of the addend of the relocation (only used for SHT_REL).
748 get_size_for_reloc(unsigned int, Relobj*);
751 // Adjust TLS relocation type based on the options and whether this
752 // is a local symbol.
753 static tls::Tls_optimization
754 optimize_tls_reloc(bool is_final, int r_type);
756 // Check if relocation against this symbol is a candidate for
758 // mov foo@GOT(%reg), %reg
760 // lea foo@GOTOFF(%reg), %reg.
762 can_convert_mov_to_lea(const Symbol* gsym)
764 gold_assert(gsym != NULL);
765 return (gsym->type() != elfcpp::STT_GNU_IFUNC
766 && !gsym->is_undefined ()
767 && !gsym->is_from_dynobj()
768 && !gsym->is_preemptible()
769 && (!parameters->options().shared()
770 || (gsym->visibility() != elfcpp::STV_DEFAULT
771 && gsym->visibility() != elfcpp::STV_PROTECTED)
772 || parameters->options().Bsymbolic())
773 && strcmp(gsym->name(), "_DYNAMIC") != 0);
776 // Get the GOT section, creating it if necessary.
777 Output_data_got<32, false>*
778 got_section(Symbol_table*, Layout*);
780 // Get the GOT PLT section.
781 Output_data_got_plt_i386*
782 got_plt_section() const
784 gold_assert(this->got_plt_ != NULL);
785 return this->got_plt_;
788 // Get the GOT section for TLSDESC entries.
789 Output_data_got<32, false>*
790 got_tlsdesc_section() const
792 gold_assert(this->got_tlsdesc_ != NULL);
793 return this->got_tlsdesc_;
796 // Create the PLT section.
798 make_plt_section(Symbol_table* symtab, Layout* layout);
800 // Create a PLT entry for a global symbol.
802 make_plt_entry(Symbol_table*, Layout*, Symbol*);
804 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
806 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
807 Sized_relobj_file<32, false>* relobj,
808 unsigned int local_sym_index);
810 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
812 define_tls_base_symbol(Symbol_table*, Layout*);
814 // Create a GOT entry for the TLS module index.
816 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
817 Sized_relobj_file<32, false>* object);
819 // Get the PLT section.
820 Output_data_plt_i386*
823 gold_assert(this->plt_ != NULL);
827 // Get the dynamic reloc section, creating it if necessary.
829 rel_dyn_section(Layout*);
831 // Get the section to use for TLS_DESC relocations.
833 rel_tls_desc_section(Layout*) const;
835 // Get the section to use for IRELATIVE relocations.
837 rel_irelative_section(Layout*);
839 // Add a potential copy relocation.
841 copy_reloc(Symbol_table* symtab, Layout* layout,
842 Sized_relobj_file<32, false>* object,
843 unsigned int shndx, Output_section* output_section,
844 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
846 unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
847 this->copy_relocs_.copy_reloc(symtab, layout,
848 symtab->get_sized_symbol<32>(sym),
849 object, shndx, output_section,
850 r_type, reloc.get_r_offset(), 0,
851 this->rel_dyn_section(layout));
854 // Information about this specific target which we pass to the
855 // general Target structure.
856 static const Target::Target_info i386_info;
858 // The types of GOT entries needed for this platform.
859 // These values are exposed to the ABI in an incremental link.
860 // Do not renumber existing values without changing the version
861 // number of the .gnu_incremental_inputs section.
864 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
865 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
866 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
867 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
868 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
872 Output_data_got<32, false>* got_;
874 Output_data_plt_i386* plt_;
875 // The GOT PLT section.
876 Output_data_got_plt_i386* got_plt_;
877 // The GOT section for IRELATIVE relocations.
878 Output_data_space* got_irelative_;
879 // The GOT section for TLSDESC relocations.
880 Output_data_got<32, false>* got_tlsdesc_;
881 // The _GLOBAL_OFFSET_TABLE_ symbol.
882 Symbol* global_offset_table_;
883 // The dynamic reloc section.
884 Reloc_section* rel_dyn_;
885 // The section to use for IRELATIVE relocs.
886 Reloc_section* rel_irelative_;
887 // Relocs saved to avoid a COPY reloc.
888 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
889 // Offset of the GOT entry for the TLS module index.
890 unsigned int got_mod_index_offset_;
891 // True if the _TLS_MODULE_BASE_ symbol has been defined.
892 bool tls_base_symbol_defined_;
895 const Target::Target_info Target_i386::i386_info =
898 false, // is_big_endian
899 elfcpp::EM_386, // machine_code
900 false, // has_make_symbol
901 false, // has_resolve
902 true, // has_code_fill
903 true, // is_default_stack_executable
904 true, // can_icf_inline_merge_sections
906 "/usr/lib/libc.so.1", // dynamic_linker
907 0x08048000, // default_text_segment_address
908 0x1000, // abi_pagesize (overridable by -z max-page-size)
909 0x1000, // common_pagesize (overridable by -z common-page-size)
910 false, // isolate_execinstr
912 elfcpp::SHN_UNDEF, // small_common_shndx
913 elfcpp::SHN_UNDEF, // large_common_shndx
914 0, // small_common_section_flags
915 0, // large_common_section_flags
916 NULL, // attributes_section
917 NULL, // attributes_vendor
918 "_start", // entry_symbol_name
919 32, // hash_entry_size
922 // Get the GOT section, creating it if necessary.
924 Output_data_got<32, false>*
925 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
927 if (this->got_ == NULL)
929 gold_assert(symtab != NULL && layout != NULL);
931 this->got_ = new Output_data_got<32, false>();
933 // When using -z now, we can treat .got.plt as a relro section.
934 // Without -z now, it is modified after program startup by lazy
936 bool is_got_plt_relro = parameters->options().now();
937 Output_section_order got_order = (is_got_plt_relro
940 Output_section_order got_plt_order = (is_got_plt_relro
942 : ORDER_NON_RELRO_FIRST);
944 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
946 | elfcpp::SHF_WRITE),
947 this->got_, got_order, true);
949 this->got_plt_ = new Output_data_got_plt_i386(layout);
950 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
952 | elfcpp::SHF_WRITE),
953 this->got_plt_, got_plt_order,
956 // The first three entries are reserved.
957 this->got_plt_->set_current_data_size(3 * 4);
959 if (!is_got_plt_relro)
961 // Those bytes can go into the relro segment.
962 layout->increase_relro(3 * 4);
965 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
966 this->global_offset_table_ =
967 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
968 Symbol_table::PREDEFINED,
970 0, 0, elfcpp::STT_OBJECT,
972 elfcpp::STV_HIDDEN, 0,
975 // If there are any IRELATIVE relocations, they get GOT entries
976 // in .got.plt after the jump slot relocations.
977 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
978 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
980 | elfcpp::SHF_WRITE),
981 this->got_irelative_,
982 got_plt_order, is_got_plt_relro);
984 // If there are any TLSDESC relocations, they get GOT entries in
985 // .got.plt after the jump slot entries.
986 this->got_tlsdesc_ = new Output_data_got<32, false>();
987 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
989 | elfcpp::SHF_WRITE),
991 got_plt_order, is_got_plt_relro);
997 // Get the dynamic reloc section, creating it if necessary.
999 Target_i386::Reloc_section*
1000 Target_i386::rel_dyn_section(Layout* layout)
1002 if (this->rel_dyn_ == NULL)
1004 gold_assert(layout != NULL);
1005 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
1006 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1007 elfcpp::SHF_ALLOC, this->rel_dyn_,
1008 ORDER_DYNAMIC_RELOCS, false);
1010 return this->rel_dyn_;
1013 // Get the section to use for IRELATIVE relocs, creating it if
1014 // necessary. These go in .rel.dyn, but only after all other dynamic
1015 // relocations. They need to follow the other dynamic relocations so
1016 // that they can refer to global variables initialized by those
1019 Target_i386::Reloc_section*
1020 Target_i386::rel_irelative_section(Layout* layout)
1022 if (this->rel_irelative_ == NULL)
1024 // Make sure we have already create the dynamic reloc section.
1025 this->rel_dyn_section(layout);
1026 this->rel_irelative_ = new Reloc_section(false);
1027 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1028 elfcpp::SHF_ALLOC, this->rel_irelative_,
1029 ORDER_DYNAMIC_RELOCS, false);
1030 gold_assert(this->rel_dyn_->output_section()
1031 == this->rel_irelative_->output_section());
1033 return this->rel_irelative_;
1036 // Write the first three reserved words of the .got.plt section.
1037 // The remainder of the section is written while writing the PLT
1038 // in Output_data_plt_i386::do_write.
1041 Output_data_got_plt_i386::do_write(Output_file* of)
1043 // The first entry in the GOT is the address of the .dynamic section
1044 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1045 // We saved space for them when we created the section in
1046 // Target_i386::got_section.
1047 const off_t got_file_offset = this->offset();
1048 gold_assert(this->data_size() >= 12);
1049 unsigned char* const got_view = of->get_output_view(got_file_offset, 12);
1050 Output_section* dynamic = this->layout_->dynamic_section();
1051 uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1052 elfcpp::Swap<32, false>::writeval(got_view, dynamic_addr);
1053 memset(got_view + 4, 0, 8);
1054 of->write_output_view(got_file_offset, 12, got_view);
1057 // Create the PLT section. The ordinary .got section is an argument,
1058 // since we need to refer to the start. We also create our own .got
1059 // section just for PLT entries.
1061 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
1063 Output_data_got_plt_i386* got_plt,
1064 Output_data_space* got_irelative)
1065 : Output_section_data(addralign),
1066 tls_desc_rel_(NULL), irelative_rel_(NULL), got_plt_(got_plt),
1067 got_irelative_(got_irelative), count_(0), irelative_count_(0),
1068 global_ifuncs_(), local_ifuncs_()
1070 this->rel_ = new Reloc_section(false);
1071 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1072 elfcpp::SHF_ALLOC, this->rel_,
1073 ORDER_DYNAMIC_PLT_RELOCS, false);
1077 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
1079 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1080 // linker, and so do we.
1084 // Add an entry to the PLT.
1087 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
1090 gold_assert(!gsym->has_plt_offset());
1092 // Every PLT entry needs a reloc.
1093 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1094 && gsym->can_use_relative_reloc(false))
1096 gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
1097 ++this->irelative_count_;
1098 section_offset_type got_offset =
1099 this->got_irelative_->current_data_size();
1100 this->got_irelative_->set_current_data_size(got_offset + 4);
1101 Reloc_section* rel = this->rel_irelative(symtab, layout);
1102 rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
1103 this->got_irelative_, got_offset);
1104 struct Global_ifunc gi;
1106 gi.got_offset = got_offset;
1107 this->global_ifuncs_.push_back(gi);
1111 // When setting the PLT offset we skip the initial reserved PLT
1113 gsym->set_plt_offset((this->count_ + 1) * this->get_plt_entry_size());
1117 section_offset_type got_offset = this->got_plt_->current_data_size();
1119 // Every PLT entry needs a GOT entry which points back to the
1120 // PLT entry (this will be changed by the dynamic linker,
1121 // normally lazily when the function is called).
1122 this->got_plt_->set_current_data_size(got_offset + 4);
1124 gsym->set_needs_dynsym_entry();
1125 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
1129 // Note that we don't need to save the symbol. The contents of the
1130 // PLT are independent of which symbols are used. The symbols only
1131 // appear in the relocations.
1134 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1138 Output_data_plt_i386::add_local_ifunc_entry(
1139 Symbol_table* symtab,
1141 Sized_relobj_file<32, false>* relobj,
1142 unsigned int local_sym_index)
1144 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1145 ++this->irelative_count_;
1147 section_offset_type got_offset = this->got_irelative_->current_data_size();
1149 // Every PLT entry needs a GOT entry which points back to the PLT
1151 this->got_irelative_->set_current_data_size(got_offset + 4);
1153 // Every PLT entry needs a reloc.
1154 Reloc_section* rel = this->rel_irelative(symtab, layout);
1155 rel->add_symbolless_local_addend(relobj, local_sym_index,
1156 elfcpp::R_386_IRELATIVE,
1157 this->got_irelative_, got_offset);
1159 struct Local_ifunc li;
1161 li.local_sym_index = local_sym_index;
1162 li.got_offset = got_offset;
1163 this->local_ifuncs_.push_back(li);
1168 // Return where the TLS_DESC relocations should go, creating it if
1169 // necessary. These follow the JUMP_SLOT relocations.
1171 Output_data_plt_i386::Reloc_section*
1172 Output_data_plt_i386::rel_tls_desc(Layout* layout)
1174 if (this->tls_desc_rel_ == NULL)
1176 this->tls_desc_rel_ = new Reloc_section(false);
1177 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1178 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
1179 ORDER_DYNAMIC_PLT_RELOCS, false);
1180 gold_assert(this->tls_desc_rel_->output_section()
1181 == this->rel_->output_section());
1183 return this->tls_desc_rel_;
1186 // Return where the IRELATIVE relocations should go in the PLT. These
1187 // follow the JUMP_SLOT and TLS_DESC relocations.
1189 Output_data_plt_i386::Reloc_section*
1190 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
1192 if (this->irelative_rel_ == NULL)
1194 // Make sure we have a place for the TLS_DESC relocations, in
1195 // case we see any later on.
1196 this->rel_tls_desc(layout);
1197 this->irelative_rel_ = new Reloc_section(false);
1198 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1199 elfcpp::SHF_ALLOC, this->irelative_rel_,
1200 ORDER_DYNAMIC_PLT_RELOCS, false);
1201 gold_assert(this->irelative_rel_->output_section()
1202 == this->rel_->output_section());
1204 if (parameters->doing_static_link())
1206 // A statically linked executable will only have a .rel.plt
1207 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1208 // symbols. The library will use these symbols to locate
1209 // the IRELATIVE relocs at program startup time.
1210 symtab->define_in_output_data("__rel_iplt_start", NULL,
1211 Symbol_table::PREDEFINED,
1212 this->irelative_rel_, 0, 0,
1213 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1214 elfcpp::STV_HIDDEN, 0, false, true);
1215 symtab->define_in_output_data("__rel_iplt_end", NULL,
1216 Symbol_table::PREDEFINED,
1217 this->irelative_rel_, 0, 0,
1218 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1219 elfcpp::STV_HIDDEN, 0, true, true);
1222 return this->irelative_rel_;
1225 // Return the PLT address to use for a global symbol.
1228 Output_data_plt_i386::address_for_global(const Symbol* gsym)
1230 uint64_t offset = 0;
1231 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1232 && gsym->can_use_relative_reloc(false))
1233 offset = (this->count_ + 1) * this->get_plt_entry_size();
1234 return this->address() + offset + gsym->plt_offset();
1237 // Return the PLT address to use for a local symbol. These are always
1238 // IRELATIVE relocs.
1241 Output_data_plt_i386::address_for_local(const Relobj* object,
1244 return (this->address()
1245 + (this->count_ + 1) * this->get_plt_entry_size()
1246 + object->local_plt_offset(r_sym));
1249 // The first entry in the PLT for an executable.
1251 const unsigned char Output_data_plt_i386_exec::first_plt_entry[plt_entry_size] =
1253 0xff, 0x35, // pushl contents of memory address
1254 0, 0, 0, 0, // replaced with address of .got + 4
1255 0xff, 0x25, // jmp indirect
1256 0, 0, 0, 0, // replaced with address of .got + 8
1257 0, 0, 0, 0 // unused
1261 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1263 elfcpp::Elf_types<32>::Elf_Addr got_address)
1265 memcpy(pov, first_plt_entry, plt_entry_size);
1266 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1267 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1270 // The first entry in the PLT for a shared object.
1272 const unsigned char Output_data_plt_i386_dyn::first_plt_entry[plt_entry_size] =
1274 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1275 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1276 0, 0, 0, 0 // unused
1280 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1282 elfcpp::Elf_types<32>::Elf_Addr)
1284 memcpy(pov, first_plt_entry, plt_entry_size);
1287 // Subsequent entries in the PLT for an executable.
1289 const unsigned char Output_data_plt_i386_exec::plt_entry[plt_entry_size] =
1291 0xff, 0x25, // jmp indirect
1292 0, 0, 0, 0, // replaced with address of symbol in .got
1293 0x68, // pushl immediate
1294 0, 0, 0, 0, // replaced with offset into relocation table
1295 0xe9, // jmp relative
1296 0, 0, 0, 0 // replaced with offset to start of .plt
1300 Output_data_plt_i386_exec::do_fill_plt_entry(
1302 elfcpp::Elf_types<32>::Elf_Addr got_address,
1303 unsigned int got_offset,
1304 unsigned int plt_offset,
1305 unsigned int plt_rel_offset)
1307 memcpy(pov, plt_entry, plt_entry_size);
1308 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1309 got_address + got_offset);
1310 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1311 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1315 // Subsequent entries in the PLT for a shared object.
1317 const unsigned char Output_data_plt_i386_dyn::plt_entry[plt_entry_size] =
1319 0xff, 0xa3, // jmp *offset(%ebx)
1320 0, 0, 0, 0, // replaced with offset of symbol in .got
1321 0x68, // pushl immediate
1322 0, 0, 0, 0, // replaced with offset into relocation table
1323 0xe9, // jmp relative
1324 0, 0, 0, 0 // replaced with offset to start of .plt
1328 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
1329 elfcpp::Elf_types<32>::Elf_Addr,
1330 unsigned int got_offset,
1331 unsigned int plt_offset,
1332 unsigned int plt_rel_offset)
1334 memcpy(pov, plt_entry, plt_entry_size);
1335 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1336 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1337 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1341 // The .eh_frame unwind information for the PLT.
1344 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1347 'z', // Augmentation: augmentation size included.
1348 'R', // Augmentation: FDE encoding included.
1349 '\0', // End of augmentation string.
1350 1, // Code alignment factor.
1351 0x7c, // Data alignment factor.
1352 8, // Return address column.
1353 1, // Augmentation size.
1354 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1355 | elfcpp::DW_EH_PE_sdata4),
1356 elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1357 elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1358 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1363 Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1365 0, 0, 0, 0, // Replaced with offset to .plt.
1366 0, 0, 0, 0, // Replaced with size of .plt.
1367 0, // Augmentation size.
1368 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
1369 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1370 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
1371 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1372 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1373 11, // Block length.
1374 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
1375 elfcpp::DW_OP_breg8, 0, // Push %eip.
1376 elfcpp::DW_OP_lit15, // Push 0xf.
1377 elfcpp::DW_OP_and, // & (%eip & 0xf).
1378 elfcpp::DW_OP_lit11, // Push 0xb.
1379 elfcpp::DW_OP_ge, // >= ((%eip & 0xf) >= 0xb)
1380 elfcpp::DW_OP_lit2, // Push 2.
1381 elfcpp::DW_OP_shl, // << (((%eip & 0xf) >= 0xb) << 2)
1382 elfcpp::DW_OP_plus, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1383 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1389 // Write out the PLT. This uses the hand-coded instructions above,
1390 // and adjusts them as needed. This is all specified by the i386 ELF
1391 // Processor Supplement.
1394 Output_data_plt_i386::do_write(Output_file* of)
1396 const off_t offset = this->offset();
1397 const section_size_type oview_size =
1398 convert_to_section_size_type(this->data_size());
1399 unsigned char* const oview = of->get_output_view(offset, oview_size);
1401 const off_t got_file_offset = this->got_plt_->offset();
1402 gold_assert(parameters->incremental_update()
1403 || (got_file_offset + this->got_plt_->data_size()
1404 == this->got_irelative_->offset()));
1405 const section_size_type got_size =
1406 convert_to_section_size_type(this->got_plt_->data_size()
1407 + this->got_irelative_->data_size());
1409 unsigned char* const got_view = of->get_output_view(got_file_offset,
1412 unsigned char* pov = oview;
1414 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1415 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1417 this->fill_first_plt_entry(pov, got_address);
1418 pov += this->get_plt_entry_size();
1420 // The first three entries in the GOT are reserved, and are written
1421 // by Output_data_got_plt_i386::do_write.
1422 unsigned char* got_pov = got_view + 12;
1424 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1426 unsigned int plt_offset = this->get_plt_entry_size();
1427 unsigned int plt_rel_offset = 0;
1428 unsigned int got_offset = 12;
1429 const unsigned int count = this->count_ + this->irelative_count_;
1430 for (unsigned int i = 0;
1433 pov += this->get_plt_entry_size(),
1435 plt_offset += this->get_plt_entry_size(),
1436 plt_rel_offset += rel_size,
1439 // Set and adjust the PLT entry itself.
1440 unsigned int lazy_offset = this->fill_plt_entry(pov,
1446 // Set the entry in the GOT.
1447 elfcpp::Swap<32, false>::writeval(got_pov,
1448 plt_address + plt_offset + lazy_offset);
1451 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1452 // the GOT to point to the actual symbol value, rather than point to
1453 // the PLT entry. That will let the dynamic linker call the right
1454 // function when resolving IRELATIVE relocations.
1455 unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1456 for (std::vector<Global_ifunc>::const_iterator p =
1457 this->global_ifuncs_.begin();
1458 p != this->global_ifuncs_.end();
1461 const Sized_symbol<32>* ssym =
1462 static_cast<const Sized_symbol<32>*>(p->sym);
1463 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1467 for (std::vector<Local_ifunc>::const_iterator p =
1468 this->local_ifuncs_.begin();
1469 p != this->local_ifuncs_.end();
1472 const Symbol_value<32>* psymval =
1473 p->object->local_symbol(p->local_sym_index);
1474 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1475 psymval->value(p->object, 0));
1478 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1479 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1481 of->write_output_view(offset, oview_size, oview);
1482 of->write_output_view(got_file_offset, got_size, got_view);
1485 // Create the PLT section.
1488 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1490 if (this->plt_ == NULL)
1492 // Create the GOT sections first.
1493 this->got_section(symtab, layout);
1495 const bool dyn = parameters->options().output_is_position_independent();
1496 this->plt_ = this->make_data_plt(layout,
1498 this->got_irelative_,
1501 // Add unwind information if requested.
1502 if (parameters->options().ld_generated_unwind_info())
1503 this->plt_->add_eh_frame(layout);
1505 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1507 | elfcpp::SHF_EXECINSTR),
1508 this->plt_, ORDER_PLT, false);
1510 // Make the sh_info field of .rel.plt point to .plt.
1511 Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1512 rel_plt_os->set_info_section(this->plt_->output_section());
1516 // Create a PLT entry for a global symbol.
1519 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1521 if (gsym->has_plt_offset())
1523 if (this->plt_ == NULL)
1524 this->make_plt_section(symtab, layout);
1525 this->plt_->add_entry(symtab, layout, gsym);
1528 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1531 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1532 Sized_relobj_file<32, false>* relobj,
1533 unsigned int local_sym_index)
1535 if (relobj->local_has_plt_offset(local_sym_index))
1537 if (this->plt_ == NULL)
1538 this->make_plt_section(symtab, layout);
1539 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1542 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1545 // Return the number of entries in the PLT.
1548 Target_i386::plt_entry_count() const
1550 if (this->plt_ == NULL)
1552 return this->plt_->entry_count();
1555 // Return the offset of the first non-reserved PLT entry.
1558 Target_i386::first_plt_entry_offset() const
1560 return this->plt_->first_plt_entry_offset();
1563 // Return the size of each PLT entry.
1566 Target_i386::plt_entry_size() const
1568 return this->plt_->get_plt_entry_size();
1571 // Get the section to use for TLS_DESC relocations.
1573 Target_i386::Reloc_section*
1574 Target_i386::rel_tls_desc_section(Layout* layout) const
1576 return this->plt_section()->rel_tls_desc(layout);
1579 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1582 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1584 if (this->tls_base_symbol_defined_)
1587 Output_segment* tls_segment = layout->tls_segment();
1588 if (tls_segment != NULL)
1590 bool is_exec = parameters->options().output_is_executable();
1591 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1592 Symbol_table::PREDEFINED,
1596 elfcpp::STV_HIDDEN, 0,
1598 ? Symbol::SEGMENT_END
1599 : Symbol::SEGMENT_START),
1602 this->tls_base_symbol_defined_ = true;
1605 // Create a GOT entry for the TLS module index.
1608 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1609 Sized_relobj_file<32, false>* object)
1611 if (this->got_mod_index_offset_ == -1U)
1613 gold_assert(symtab != NULL && layout != NULL && object != NULL);
1614 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1615 Output_data_got<32, false>* got = this->got_section(symtab, layout);
1616 unsigned int got_offset = got->add_constant(0);
1617 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1619 got->add_constant(0);
1620 this->got_mod_index_offset_ = got_offset;
1622 return this->got_mod_index_offset_;
1625 // Optimize the TLS relocation type based on what we know about the
1626 // symbol. IS_FINAL is true if the final address of this symbol is
1627 // known at link time.
1629 tls::Tls_optimization
1630 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1632 // If we are generating a shared library, then we can't do anything
1634 if (parameters->options().shared())
1635 return tls::TLSOPT_NONE;
1639 case elfcpp::R_386_TLS_GD:
1640 case elfcpp::R_386_TLS_GOTDESC:
1641 case elfcpp::R_386_TLS_DESC_CALL:
1642 // These are General-Dynamic which permits fully general TLS
1643 // access. Since we know that we are generating an executable,
1644 // we can convert this to Initial-Exec. If we also know that
1645 // this is a local symbol, we can further switch to Local-Exec.
1647 return tls::TLSOPT_TO_LE;
1648 return tls::TLSOPT_TO_IE;
1650 case elfcpp::R_386_TLS_LDM:
1651 // This is Local-Dynamic, which refers to a local symbol in the
1652 // dynamic TLS block. Since we know that we generating an
1653 // executable, we can switch to Local-Exec.
1654 return tls::TLSOPT_TO_LE;
1656 case elfcpp::R_386_TLS_LDO_32:
1657 // Another type of Local-Dynamic relocation.
1658 return tls::TLSOPT_TO_LE;
1660 case elfcpp::R_386_TLS_IE:
1661 case elfcpp::R_386_TLS_GOTIE:
1662 case elfcpp::R_386_TLS_IE_32:
1663 // These are Initial-Exec relocs which get the thread offset
1664 // from the GOT. If we know that we are linking against the
1665 // local symbol, we can switch to Local-Exec, which links the
1666 // thread offset into the instruction.
1668 return tls::TLSOPT_TO_LE;
1669 return tls::TLSOPT_NONE;
1671 case elfcpp::R_386_TLS_LE:
1672 case elfcpp::R_386_TLS_LE_32:
1673 // When we already have Local-Exec, there is nothing further we
1675 return tls::TLSOPT_NONE;
1682 // Get the Reference_flags for a particular relocation.
1685 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1689 case elfcpp::R_386_NONE:
1690 case elfcpp::R_386_GNU_VTINHERIT:
1691 case elfcpp::R_386_GNU_VTENTRY:
1692 case elfcpp::R_386_GOTPC:
1693 // No symbol reference.
1696 case elfcpp::R_386_32:
1697 case elfcpp::R_386_16:
1698 case elfcpp::R_386_8:
1699 return Symbol::ABSOLUTE_REF;
1701 case elfcpp::R_386_PC32:
1702 case elfcpp::R_386_PC16:
1703 case elfcpp::R_386_PC8:
1704 case elfcpp::R_386_GOTOFF:
1705 return Symbol::RELATIVE_REF;
1707 case elfcpp::R_386_PLT32:
1708 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1710 case elfcpp::R_386_GOT32:
1711 case elfcpp::R_386_GOT32X:
1713 return Symbol::ABSOLUTE_REF;
1715 case elfcpp::R_386_TLS_GD: // Global-dynamic
1716 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1717 case elfcpp::R_386_TLS_DESC_CALL:
1718 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1719 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1720 case elfcpp::R_386_TLS_IE: // Initial-exec
1721 case elfcpp::R_386_TLS_IE_32:
1722 case elfcpp::R_386_TLS_GOTIE:
1723 case elfcpp::R_386_TLS_LE: // Local-exec
1724 case elfcpp::R_386_TLS_LE_32:
1725 return Symbol::TLS_REF;
1727 case elfcpp::R_386_COPY:
1728 case elfcpp::R_386_GLOB_DAT:
1729 case elfcpp::R_386_JUMP_SLOT:
1730 case elfcpp::R_386_RELATIVE:
1731 case elfcpp::R_386_IRELATIVE:
1732 case elfcpp::R_386_TLS_TPOFF:
1733 case elfcpp::R_386_TLS_DTPMOD32:
1734 case elfcpp::R_386_TLS_DTPOFF32:
1735 case elfcpp::R_386_TLS_TPOFF32:
1736 case elfcpp::R_386_TLS_DESC:
1737 case elfcpp::R_386_32PLT:
1738 case elfcpp::R_386_TLS_GD_32:
1739 case elfcpp::R_386_TLS_GD_PUSH:
1740 case elfcpp::R_386_TLS_GD_CALL:
1741 case elfcpp::R_386_TLS_GD_POP:
1742 case elfcpp::R_386_TLS_LDM_32:
1743 case elfcpp::R_386_TLS_LDM_PUSH:
1744 case elfcpp::R_386_TLS_LDM_CALL:
1745 case elfcpp::R_386_TLS_LDM_POP:
1746 case elfcpp::R_386_USED_BY_INTEL_200:
1748 // Not expected. We will give an error later.
1753 // Report an unsupported relocation against a local symbol.
1756 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1757 unsigned int r_type)
1759 gold_error(_("%s: unsupported reloc %u against local symbol"),
1760 object->name().c_str(), r_type);
1763 // Return whether we need to make a PLT entry for a relocation of a
1764 // given type against a STT_GNU_IFUNC symbol.
1767 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1768 Sized_relobj_file<32, false>* object,
1769 unsigned int r_type)
1771 int flags = Scan::get_reference_flags(r_type);
1772 if (flags & Symbol::TLS_REF)
1773 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1774 object->name().c_str(), r_type);
1778 // Scan a relocation for a local symbol.
1781 Target_i386::Scan::local(Symbol_table* symtab,
1783 Target_i386* target,
1784 Sized_relobj_file<32, false>* object,
1785 unsigned int data_shndx,
1786 Output_section* output_section,
1787 const elfcpp::Rel<32, false>& reloc,
1788 unsigned int r_type,
1789 const elfcpp::Sym<32, false>& lsym,
1795 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1796 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1797 && this->reloc_needs_plt_for_ifunc(object, r_type))
1799 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1800 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1805 case elfcpp::R_386_NONE:
1806 case elfcpp::R_386_GNU_VTINHERIT:
1807 case elfcpp::R_386_GNU_VTENTRY:
1810 case elfcpp::R_386_32:
1811 // If building a shared library (or a position-independent
1812 // executable), we need to create a dynamic relocation for
1813 // this location. The relocation applied at link time will
1814 // apply the link-time value, so we flag the location with
1815 // an R_386_RELATIVE relocation so the dynamic loader can
1816 // relocate it easily.
1817 if (parameters->options().output_is_position_independent())
1819 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1820 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1821 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1822 output_section, data_shndx,
1823 reloc.get_r_offset());
1827 case elfcpp::R_386_16:
1828 case elfcpp::R_386_8:
1829 // If building a shared library (or a position-independent
1830 // executable), we need to create a dynamic relocation for
1831 // this location. Because the addend needs to remain in the
1832 // data section, we need to be careful not to apply this
1833 // relocation statically.
1834 if (parameters->options().output_is_position_independent())
1836 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1837 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1838 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1839 rel_dyn->add_local(object, r_sym, r_type, output_section,
1840 data_shndx, reloc.get_r_offset());
1843 gold_assert(lsym.get_st_value() == 0);
1844 unsigned int shndx = lsym.get_st_shndx();
1846 shndx = object->adjust_sym_shndx(r_sym, shndx,
1849 object->error(_("section symbol %u has bad shndx %u"),
1852 rel_dyn->add_local_section(object, shndx,
1853 r_type, output_section,
1854 data_shndx, reloc.get_r_offset());
1859 case elfcpp::R_386_PC32:
1860 case elfcpp::R_386_PC16:
1861 case elfcpp::R_386_PC8:
1864 case elfcpp::R_386_PLT32:
1865 // Since we know this is a local symbol, we can handle this as a
1869 case elfcpp::R_386_GOTOFF:
1870 case elfcpp::R_386_GOTPC:
1871 // We need a GOT section.
1872 target->got_section(symtab, layout);
1875 case elfcpp::R_386_GOT32:
1876 case elfcpp::R_386_GOT32X:
1878 // We need GOT section.
1879 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1881 // If the relocation symbol isn't IFUNC,
1882 // and is local, then we will convert
1883 // mov foo@GOT(%reg), %reg
1885 // lea foo@GOTOFF(%reg), %reg
1886 // in Relocate::relocate.
1887 if (reloc.get_r_offset() >= 2
1888 && lsym.get_st_type() != elfcpp::STT_GNU_IFUNC)
1890 section_size_type stype;
1891 const unsigned char* view = object->section_contents(data_shndx,
1893 if (view[reloc.get_r_offset() - 2] == 0x8b)
1897 // Otherwise, the symbol requires a GOT entry.
1898 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1900 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1901 // lets function pointers compare correctly with shared
1902 // libraries. Otherwise we would need an IRELATIVE reloc.
1904 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1905 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1907 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1910 // If we are generating a shared object, we need to add a
1911 // dynamic RELATIVE relocation for this symbol's GOT entry.
1912 if (parameters->options().output_is_position_independent())
1914 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1915 unsigned int got_offset =
1916 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1917 rel_dyn->add_local_relative(object, r_sym,
1918 elfcpp::R_386_RELATIVE,
1925 // These are relocations which should only be seen by the
1926 // dynamic linker, and should never be seen here.
1927 case elfcpp::R_386_COPY:
1928 case elfcpp::R_386_GLOB_DAT:
1929 case elfcpp::R_386_JUMP_SLOT:
1930 case elfcpp::R_386_RELATIVE:
1931 case elfcpp::R_386_IRELATIVE:
1932 case elfcpp::R_386_TLS_TPOFF:
1933 case elfcpp::R_386_TLS_DTPMOD32:
1934 case elfcpp::R_386_TLS_DTPOFF32:
1935 case elfcpp::R_386_TLS_TPOFF32:
1936 case elfcpp::R_386_TLS_DESC:
1937 gold_error(_("%s: unexpected reloc %u in object file"),
1938 object->name().c_str(), r_type);
1941 // These are initial TLS relocs, which are expected when
1943 case elfcpp::R_386_TLS_GD: // Global-dynamic
1944 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1945 case elfcpp::R_386_TLS_DESC_CALL:
1946 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1947 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1948 case elfcpp::R_386_TLS_IE: // Initial-exec
1949 case elfcpp::R_386_TLS_IE_32:
1950 case elfcpp::R_386_TLS_GOTIE:
1951 case elfcpp::R_386_TLS_LE: // Local-exec
1952 case elfcpp::R_386_TLS_LE_32:
1954 bool output_is_shared = parameters->options().shared();
1955 const tls::Tls_optimization optimized_type
1956 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1959 case elfcpp::R_386_TLS_GD: // Global-dynamic
1960 if (optimized_type == tls::TLSOPT_NONE)
1962 // Create a pair of GOT entries for the module index and
1963 // dtv-relative offset.
1964 Output_data_got<32, false>* got
1965 = target->got_section(symtab, layout);
1966 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1967 unsigned int shndx = lsym.get_st_shndx();
1969 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1971 object->error(_("local symbol %u has bad shndx %u"),
1974 got->add_local_pair_with_rel(object, r_sym, shndx,
1976 target->rel_dyn_section(layout),
1977 elfcpp::R_386_TLS_DTPMOD32);
1979 else if (optimized_type != tls::TLSOPT_TO_LE)
1980 unsupported_reloc_local(object, r_type);
1983 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1984 target->define_tls_base_symbol(symtab, layout);
1985 if (optimized_type == tls::TLSOPT_NONE)
1987 // Create a double GOT entry with an R_386_TLS_DESC
1988 // reloc. The R_386_TLS_DESC reloc is resolved
1989 // lazily, so the GOT entry needs to be in an area in
1990 // .got.plt, not .got. Call got_section to make sure
1991 // the section has been created.
1992 target->got_section(symtab, layout);
1993 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1994 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1995 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1997 unsigned int got_offset = got->add_constant(0);
1998 // The local symbol value is stored in the second
2000 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
2001 // That set the GOT offset of the local symbol to
2002 // point to the second entry, but we want it to
2003 // point to the first.
2004 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2006 Reloc_section* rt = target->rel_tls_desc_section(layout);
2007 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
2010 else if (optimized_type != tls::TLSOPT_TO_LE)
2011 unsupported_reloc_local(object, r_type);
2014 case elfcpp::R_386_TLS_DESC_CALL:
2017 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2018 if (optimized_type == tls::TLSOPT_NONE)
2020 // Create a GOT entry for the module index.
2021 target->got_mod_index_entry(symtab, layout, object);
2023 else if (optimized_type != tls::TLSOPT_TO_LE)
2024 unsupported_reloc_local(object, r_type);
2027 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2030 case elfcpp::R_386_TLS_IE: // Initial-exec
2031 case elfcpp::R_386_TLS_IE_32:
2032 case elfcpp::R_386_TLS_GOTIE:
2033 layout->set_has_static_tls();
2034 if (optimized_type == tls::TLSOPT_NONE)
2036 // For the R_386_TLS_IE relocation, we need to create a
2037 // dynamic relocation when building a shared library.
2038 if (r_type == elfcpp::R_386_TLS_IE
2039 && parameters->options().shared())
2041 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2043 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2044 rel_dyn->add_local_relative(object, r_sym,
2045 elfcpp::R_386_RELATIVE,
2046 output_section, data_shndx,
2047 reloc.get_r_offset());
2049 // Create a GOT entry for the tp-relative offset.
2050 Output_data_got<32, false>* got
2051 = target->got_section(symtab, layout);
2052 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2053 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2054 ? elfcpp::R_386_TLS_TPOFF32
2055 : elfcpp::R_386_TLS_TPOFF);
2056 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2057 ? GOT_TYPE_TLS_OFFSET
2058 : GOT_TYPE_TLS_NOFFSET);
2059 got->add_local_with_rel(object, r_sym, got_type,
2060 target->rel_dyn_section(layout),
2063 else if (optimized_type != tls::TLSOPT_TO_LE)
2064 unsupported_reloc_local(object, r_type);
2067 case elfcpp::R_386_TLS_LE: // Local-exec
2068 case elfcpp::R_386_TLS_LE_32:
2069 layout->set_has_static_tls();
2070 if (output_is_shared)
2072 // We need to create a dynamic relocation.
2073 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2074 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2075 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2076 ? elfcpp::R_386_TLS_TPOFF32
2077 : elfcpp::R_386_TLS_TPOFF);
2078 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2079 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
2080 data_shndx, reloc.get_r_offset());
2090 case elfcpp::R_386_32PLT:
2091 case elfcpp::R_386_TLS_GD_32:
2092 case elfcpp::R_386_TLS_GD_PUSH:
2093 case elfcpp::R_386_TLS_GD_CALL:
2094 case elfcpp::R_386_TLS_GD_POP:
2095 case elfcpp::R_386_TLS_LDM_32:
2096 case elfcpp::R_386_TLS_LDM_PUSH:
2097 case elfcpp::R_386_TLS_LDM_CALL:
2098 case elfcpp::R_386_TLS_LDM_POP:
2099 case elfcpp::R_386_USED_BY_INTEL_200:
2101 unsupported_reloc_local(object, r_type);
2106 // Report an unsupported relocation against a global symbol.
2109 Target_i386::Scan::unsupported_reloc_global(
2110 Sized_relobj_file<32, false>* object,
2111 unsigned int r_type,
2114 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2115 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2119 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
2123 case elfcpp::R_386_32:
2124 case elfcpp::R_386_16:
2125 case elfcpp::R_386_8:
2126 case elfcpp::R_386_GOTOFF:
2127 case elfcpp::R_386_GOT32:
2128 case elfcpp::R_386_GOT32X:
2139 Target_i386::Scan::local_reloc_may_be_function_pointer(
2143 Sized_relobj_file<32, false>* ,
2146 const elfcpp::Rel<32, false>& ,
2147 unsigned int r_type,
2148 const elfcpp::Sym<32, false>&)
2150 return possible_function_pointer_reloc(r_type);
2154 Target_i386::Scan::global_reloc_may_be_function_pointer(
2158 Sized_relobj_file<32, false>* ,
2161 const elfcpp::Rel<32, false>& ,
2162 unsigned int r_type,
2165 return possible_function_pointer_reloc(r_type);
2168 // Scan a relocation for a global symbol.
2171 Target_i386::Scan::global(Symbol_table* symtab,
2173 Target_i386* target,
2174 Sized_relobj_file<32, false>* object,
2175 unsigned int data_shndx,
2176 Output_section* output_section,
2177 const elfcpp::Rel<32, false>& reloc,
2178 unsigned int r_type,
2181 // A STT_GNU_IFUNC symbol may require a PLT entry.
2182 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2183 && this->reloc_needs_plt_for_ifunc(object, r_type))
2184 target->make_plt_entry(symtab, layout, gsym);
2188 case elfcpp::R_386_NONE:
2189 case elfcpp::R_386_GNU_VTINHERIT:
2190 case elfcpp::R_386_GNU_VTENTRY:
2193 case elfcpp::R_386_32:
2194 case elfcpp::R_386_16:
2195 case elfcpp::R_386_8:
2197 // Make a PLT entry if necessary.
2198 if (gsym->needs_plt_entry())
2200 target->make_plt_entry(symtab, layout, gsym);
2201 // Since this is not a PC-relative relocation, we may be
2202 // taking the address of a function. In that case we need to
2203 // set the entry in the dynamic symbol table to the address of
2205 if (gsym->is_from_dynobj() && !parameters->options().shared())
2206 gsym->set_needs_dynsym_value();
2208 // Make a dynamic relocation if necessary.
2209 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2211 if (!parameters->options().output_is_position_independent()
2212 && gsym->may_need_copy_reloc())
2214 target->copy_reloc(symtab, layout, object,
2215 data_shndx, output_section, gsym, reloc);
2217 else if (r_type == elfcpp::R_386_32
2218 && gsym->type() == elfcpp::STT_GNU_IFUNC
2219 && gsym->can_use_relative_reloc(false)
2220 && !gsym->is_from_dynobj()
2221 && !gsym->is_undefined()
2222 && !gsym->is_preemptible())
2224 // Use an IRELATIVE reloc for a locally defined
2225 // STT_GNU_IFUNC symbol. This makes a function
2226 // address in a PIE executable match the address in a
2227 // shared library that it links against.
2228 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
2229 rel_dyn->add_symbolless_global_addend(gsym,
2230 elfcpp::R_386_IRELATIVE,
2233 reloc.get_r_offset());
2235 else if (r_type == elfcpp::R_386_32
2236 && gsym->can_use_relative_reloc(false))
2238 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2239 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2240 output_section, object,
2241 data_shndx, reloc.get_r_offset());
2245 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2246 rel_dyn->add_global(gsym, r_type, output_section, object,
2247 data_shndx, reloc.get_r_offset());
2253 case elfcpp::R_386_PC32:
2254 case elfcpp::R_386_PC16:
2255 case elfcpp::R_386_PC8:
2257 // Make a PLT entry if necessary.
2258 if (gsym->needs_plt_entry())
2260 // These relocations are used for function calls only in
2261 // non-PIC code. For a 32-bit relocation in a shared library,
2262 // we'll need a text relocation anyway, so we can skip the
2263 // PLT entry and let the dynamic linker bind the call directly
2264 // to the target. For smaller relocations, we should use a
2265 // PLT entry to ensure that the call can reach.
2266 if (!parameters->options().shared()
2267 || r_type != elfcpp::R_386_PC32)
2268 target->make_plt_entry(symtab, layout, gsym);
2270 // Make a dynamic relocation if necessary.
2271 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2273 if (parameters->options().output_is_executable()
2274 && gsym->may_need_copy_reloc())
2276 target->copy_reloc(symtab, layout, object,
2277 data_shndx, output_section, gsym, reloc);
2281 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2282 rel_dyn->add_global(gsym, r_type, output_section, object,
2283 data_shndx, reloc.get_r_offset());
2289 case elfcpp::R_386_GOT32:
2290 case elfcpp::R_386_GOT32X:
2292 // The symbol requires a GOT section.
2293 Output_data_got<32, false>* got = target->got_section(symtab, layout);
2295 // If we convert this from
2296 // mov foo@GOT(%reg), %reg
2298 // lea foo@GOTOFF(%reg), %reg
2299 // in Relocate::relocate, then there is nothing to do here.
2300 if (reloc.get_r_offset() >= 2
2301 && Target_i386::can_convert_mov_to_lea(gsym))
2303 section_size_type stype;
2304 const unsigned char* view = object->section_contents(data_shndx,
2306 if (view[reloc.get_r_offset() - 2] == 0x8b)
2310 if (gsym->final_value_is_known())
2312 // For a STT_GNU_IFUNC symbol we want the PLT address.
2313 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2314 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2316 got->add_global(gsym, GOT_TYPE_STANDARD);
2320 // If this symbol is not fully resolved, we need to add a
2321 // GOT entry with a dynamic relocation.
2322 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2324 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2326 // 1) The symbol may be defined in some other module.
2328 // 2) We are building a shared library and this is a
2329 // protected symbol; using GLOB_DAT means that the dynamic
2330 // linker can use the address of the PLT in the main
2331 // executable when appropriate so that function address
2332 // comparisons work.
2334 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2335 // code, again so that function address comparisons work.
2336 if (gsym->is_from_dynobj()
2337 || gsym->is_undefined()
2338 || gsym->is_preemptible()
2339 || (gsym->visibility() == elfcpp::STV_PROTECTED
2340 && parameters->options().shared())
2341 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2342 && parameters->options().output_is_position_independent()))
2343 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2344 rel_dyn, elfcpp::R_386_GLOB_DAT);
2347 // For a STT_GNU_IFUNC symbol we want to write the PLT
2348 // offset into the GOT, so that function pointer
2349 // comparisons work correctly.
2351 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2352 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2355 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2356 // Tell the dynamic linker to use the PLT address
2357 // when resolving relocations.
2358 if (gsym->is_from_dynobj()
2359 && !parameters->options().shared())
2360 gsym->set_needs_dynsym_value();
2364 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2365 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2373 case elfcpp::R_386_PLT32:
2374 // If the symbol is fully resolved, this is just a PC32 reloc.
2375 // Otherwise we need a PLT entry.
2376 if (gsym->final_value_is_known())
2378 // If building a shared library, we can also skip the PLT entry
2379 // if the symbol is defined in the output file and is protected
2381 if (gsym->is_defined()
2382 && !gsym->is_from_dynobj()
2383 && !gsym->is_preemptible())
2385 target->make_plt_entry(symtab, layout, gsym);
2388 case elfcpp::R_386_GOTOFF:
2389 case elfcpp::R_386_GOTPC:
2390 // We need a GOT section.
2391 target->got_section(symtab, layout);
2394 // These are relocations which should only be seen by the
2395 // dynamic linker, and should never be seen here.
2396 case elfcpp::R_386_COPY:
2397 case elfcpp::R_386_GLOB_DAT:
2398 case elfcpp::R_386_JUMP_SLOT:
2399 case elfcpp::R_386_RELATIVE:
2400 case elfcpp::R_386_IRELATIVE:
2401 case elfcpp::R_386_TLS_TPOFF:
2402 case elfcpp::R_386_TLS_DTPMOD32:
2403 case elfcpp::R_386_TLS_DTPOFF32:
2404 case elfcpp::R_386_TLS_TPOFF32:
2405 case elfcpp::R_386_TLS_DESC:
2406 gold_error(_("%s: unexpected reloc %u in object file"),
2407 object->name().c_str(), r_type);
2410 // These are initial tls relocs, which are expected when
2412 case elfcpp::R_386_TLS_GD: // Global-dynamic
2413 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2414 case elfcpp::R_386_TLS_DESC_CALL:
2415 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2416 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2417 case elfcpp::R_386_TLS_IE: // Initial-exec
2418 case elfcpp::R_386_TLS_IE_32:
2419 case elfcpp::R_386_TLS_GOTIE:
2420 case elfcpp::R_386_TLS_LE: // Local-exec
2421 case elfcpp::R_386_TLS_LE_32:
2423 const bool is_final = gsym->final_value_is_known();
2424 const tls::Tls_optimization optimized_type
2425 = Target_i386::optimize_tls_reloc(is_final, r_type);
2428 case elfcpp::R_386_TLS_GD: // Global-dynamic
2429 if (optimized_type == tls::TLSOPT_NONE)
2431 // Create a pair of GOT entries for the module index and
2432 // dtv-relative offset.
2433 Output_data_got<32, false>* got
2434 = target->got_section(symtab, layout);
2435 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2436 target->rel_dyn_section(layout),
2437 elfcpp::R_386_TLS_DTPMOD32,
2438 elfcpp::R_386_TLS_DTPOFF32);
2440 else if (optimized_type == tls::TLSOPT_TO_IE)
2442 // Create a GOT entry for the tp-relative offset.
2443 Output_data_got<32, false>* got
2444 = target->got_section(symtab, layout);
2445 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2446 target->rel_dyn_section(layout),
2447 elfcpp::R_386_TLS_TPOFF);
2449 else if (optimized_type != tls::TLSOPT_TO_LE)
2450 unsupported_reloc_global(object, r_type, gsym);
2453 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
2454 target->define_tls_base_symbol(symtab, layout);
2455 if (optimized_type == tls::TLSOPT_NONE)
2457 // Create a double GOT entry with an R_386_TLS_DESC
2458 // reloc. The R_386_TLS_DESC reloc is resolved
2459 // lazily, so the GOT entry needs to be in an area in
2460 // .got.plt, not .got. Call got_section to make sure
2461 // the section has been created.
2462 target->got_section(symtab, layout);
2463 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2464 Reloc_section* rt = target->rel_tls_desc_section(layout);
2465 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2466 elfcpp::R_386_TLS_DESC, 0);
2468 else if (optimized_type == tls::TLSOPT_TO_IE)
2470 // Create a GOT entry for the tp-relative offset.
2471 Output_data_got<32, false>* got
2472 = target->got_section(symtab, layout);
2473 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2474 target->rel_dyn_section(layout),
2475 elfcpp::R_386_TLS_TPOFF);
2477 else if (optimized_type != tls::TLSOPT_TO_LE)
2478 unsupported_reloc_global(object, r_type, gsym);
2481 case elfcpp::R_386_TLS_DESC_CALL:
2484 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2485 if (optimized_type == tls::TLSOPT_NONE)
2487 // Create a GOT entry for the module index.
2488 target->got_mod_index_entry(symtab, layout, object);
2490 else if (optimized_type != tls::TLSOPT_TO_LE)
2491 unsupported_reloc_global(object, r_type, gsym);
2494 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2497 case elfcpp::R_386_TLS_IE: // Initial-exec
2498 case elfcpp::R_386_TLS_IE_32:
2499 case elfcpp::R_386_TLS_GOTIE:
2500 layout->set_has_static_tls();
2501 if (optimized_type == tls::TLSOPT_NONE)
2503 // For the R_386_TLS_IE relocation, we need to create a
2504 // dynamic relocation when building a shared library.
2505 if (r_type == elfcpp::R_386_TLS_IE
2506 && parameters->options().shared())
2508 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2509 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2510 output_section, object,
2512 reloc.get_r_offset());
2514 // Create a GOT entry for the tp-relative offset.
2515 Output_data_got<32, false>* got
2516 = target->got_section(symtab, layout);
2517 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2518 ? elfcpp::R_386_TLS_TPOFF32
2519 : elfcpp::R_386_TLS_TPOFF);
2520 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2521 ? GOT_TYPE_TLS_OFFSET
2522 : GOT_TYPE_TLS_NOFFSET);
2523 got->add_global_with_rel(gsym, got_type,
2524 target->rel_dyn_section(layout),
2527 else if (optimized_type != tls::TLSOPT_TO_LE)
2528 unsupported_reloc_global(object, r_type, gsym);
2531 case elfcpp::R_386_TLS_LE: // Local-exec
2532 case elfcpp::R_386_TLS_LE_32:
2533 layout->set_has_static_tls();
2534 if (parameters->options().shared())
2536 // We need to create a dynamic relocation.
2537 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2538 ? elfcpp::R_386_TLS_TPOFF32
2539 : elfcpp::R_386_TLS_TPOFF);
2540 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2541 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2542 data_shndx, reloc.get_r_offset());
2552 case elfcpp::R_386_32PLT:
2553 case elfcpp::R_386_TLS_GD_32:
2554 case elfcpp::R_386_TLS_GD_PUSH:
2555 case elfcpp::R_386_TLS_GD_CALL:
2556 case elfcpp::R_386_TLS_GD_POP:
2557 case elfcpp::R_386_TLS_LDM_32:
2558 case elfcpp::R_386_TLS_LDM_PUSH:
2559 case elfcpp::R_386_TLS_LDM_CALL:
2560 case elfcpp::R_386_TLS_LDM_POP:
2561 case elfcpp::R_386_USED_BY_INTEL_200:
2563 unsupported_reloc_global(object, r_type, gsym);
2568 // Process relocations for gc.
2571 Target_i386::gc_process_relocs(Symbol_table* symtab,
2573 Sized_relobj_file<32, false>* object,
2574 unsigned int data_shndx,
2576 const unsigned char* prelocs,
2578 Output_section* output_section,
2579 bool needs_special_offset_handling,
2580 size_t local_symbol_count,
2581 const unsigned char* plocal_symbols)
2583 gold::gc_process_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2592 needs_special_offset_handling,
2597 // Scan relocations for a section.
2600 Target_i386::scan_relocs(Symbol_table* symtab,
2602 Sized_relobj_file<32, false>* object,
2603 unsigned int data_shndx,
2604 unsigned int sh_type,
2605 const unsigned char* prelocs,
2607 Output_section* output_section,
2608 bool needs_special_offset_handling,
2609 size_t local_symbol_count,
2610 const unsigned char* plocal_symbols)
2612 if (sh_type == elfcpp::SHT_RELA)
2614 gold_error(_("%s: unsupported RELA reloc section"),
2615 object->name().c_str());
2619 gold::scan_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2628 needs_special_offset_handling,
2633 // Finalize the sections.
2636 Target_i386::do_finalize_sections(
2638 const Input_objects*,
2639 Symbol_table* symtab)
2641 const Reloc_section* rel_plt = (this->plt_ == NULL
2643 : this->plt_->rel_plt());
2644 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2645 this->rel_dyn_, true, false);
2647 // Emit any relocs we saved in an attempt to avoid generating COPY
2649 if (this->copy_relocs_.any_saved_relocs())
2650 this->copy_relocs_.emit(this->rel_dyn_section(layout));
2652 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2653 // the .got.plt section.
2654 Symbol* sym = this->global_offset_table_;
2657 uint32_t data_size = this->got_plt_->current_data_size();
2658 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2661 if (parameters->doing_static_link()
2662 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2664 // If linking statically, make sure that the __rel_iplt symbols
2665 // were defined if necessary, even if we didn't create a PLT.
2666 static const Define_symbol_in_segment syms[] =
2669 "__rel_iplt_start", // name
2670 elfcpp::PT_LOAD, // segment_type
2671 elfcpp::PF_W, // segment_flags_set
2672 elfcpp::PF(0), // segment_flags_clear
2675 elfcpp::STT_NOTYPE, // type
2676 elfcpp::STB_GLOBAL, // binding
2677 elfcpp::STV_HIDDEN, // visibility
2679 Symbol::SEGMENT_START, // offset_from_base
2683 "__rel_iplt_end", // name
2684 elfcpp::PT_LOAD, // segment_type
2685 elfcpp::PF_W, // segment_flags_set
2686 elfcpp::PF(0), // segment_flags_clear
2689 elfcpp::STT_NOTYPE, // type
2690 elfcpp::STB_GLOBAL, // binding
2691 elfcpp::STV_HIDDEN, // visibility
2693 Symbol::SEGMENT_START, // offset_from_base
2698 symtab->define_symbols(layout, 2, syms,
2699 layout->script_options()->saw_sections_clause());
2703 // Return whether a direct absolute static relocation needs to be applied.
2704 // In cases where Scan::local() or Scan::global() has created
2705 // a dynamic relocation other than R_386_RELATIVE, the addend
2706 // of the relocation is carried in the data, and we must not
2707 // apply the static relocation.
2710 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2711 unsigned int r_type,
2713 Output_section* output_section)
2715 // If the output section is not allocated, then we didn't call
2716 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2718 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2721 int ref_flags = Scan::get_reference_flags(r_type);
2723 // For local symbols, we will have created a non-RELATIVE dynamic
2724 // relocation only if (a) the output is position independent,
2725 // (b) the relocation is absolute (not pc- or segment-relative), and
2726 // (c) the relocation is not 32 bits wide.
2728 return !(parameters->options().output_is_position_independent()
2729 && (ref_flags & Symbol::ABSOLUTE_REF)
2732 // For global symbols, we use the same helper routines used in the
2733 // scan pass. If we did not create a dynamic relocation, or if we
2734 // created a RELATIVE dynamic relocation, we should apply the static
2736 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2737 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2738 && gsym->can_use_relative_reloc(ref_flags
2739 & Symbol::FUNCTION_CALL);
2740 return !has_dyn || is_rel;
2743 // Perform a relocation.
2746 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2748 Target_i386* target,
2749 Output_section* output_section,
2751 const unsigned char* preloc,
2752 const Sized_symbol<32>* gsym,
2753 const Symbol_value<32>* psymval,
2754 unsigned char* view,
2755 elfcpp::Elf_types<32>::Elf_Addr address,
2756 section_size_type view_size)
2758 const elfcpp::Rel<32, false> rel(preloc);
2759 unsigned int r_type = elfcpp::elf_r_type<32>(rel.get_r_info());
2761 if (this->skip_call_tls_get_addr_)
2763 if ((r_type != elfcpp::R_386_PLT32
2764 && r_type != elfcpp::R_386_PC32)
2766 || strcmp(gsym->name(), "___tls_get_addr") != 0)
2767 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2768 _("missing expected TLS relocation"));
2771 this->skip_call_tls_get_addr_ = false;
2779 const Sized_relobj_file<32, false>* object = relinfo->object;
2781 // Pick the value to use for symbols defined in shared objects.
2782 Symbol_value<32> symval;
2784 && gsym->type() == elfcpp::STT_GNU_IFUNC
2785 && r_type == elfcpp::R_386_32
2786 && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2787 && gsym->can_use_relative_reloc(false)
2788 && !gsym->is_from_dynobj()
2789 && !gsym->is_undefined()
2790 && !gsym->is_preemptible())
2792 // In this case we are generating a R_386_IRELATIVE reloc. We
2793 // want to use the real value of the symbol, not the PLT offset.
2795 else if (gsym != NULL
2796 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2798 symval.set_output_value(target->plt_address_for_global(gsym));
2801 else if (gsym == NULL && psymval->is_ifunc_symbol())
2803 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2804 if (object->local_has_plt_offset(r_sym))
2806 symval.set_output_value(target->plt_address_for_local(object, r_sym));
2815 case elfcpp::R_386_NONE:
2816 case elfcpp::R_386_GNU_VTINHERIT:
2817 case elfcpp::R_386_GNU_VTENTRY:
2820 case elfcpp::R_386_32:
2821 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2822 Relocate_functions<32, false>::rel32(view, object, psymval);
2825 case elfcpp::R_386_PC32:
2826 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2827 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2830 case elfcpp::R_386_16:
2831 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2832 Relocate_functions<32, false>::rel16(view, object, psymval);
2835 case elfcpp::R_386_PC16:
2836 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2837 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2840 case elfcpp::R_386_8:
2841 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2842 Relocate_functions<32, false>::rel8(view, object, psymval);
2845 case elfcpp::R_386_PC8:
2846 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2847 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2850 case elfcpp::R_386_PLT32:
2851 gold_assert(gsym == NULL
2852 || gsym->has_plt_offset()
2853 || gsym->final_value_is_known()
2854 || (gsym->is_defined()
2855 && !gsym->is_from_dynobj()
2856 && !gsym->is_preemptible()));
2857 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2860 case elfcpp::R_386_GOT32:
2861 case elfcpp::R_386_GOT32X:
2862 baseless = (view[-1] & 0xc7) == 0x5;
2863 // R_386_GOT32 and R_386_GOT32X don't work without base register
2864 // when generating a position-independent output file.
2866 && parameters->options().output_is_position_independent())
2869 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2870 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2871 r_type, gsym->demangled_name().c_str());
2873 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2874 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2879 // mov foo@GOT(%reg), %reg
2881 // lea foo@GOTOFF(%reg), %reg
2883 if (rel.get_r_offset() >= 2
2885 && ((gsym == NULL && !psymval->is_ifunc_symbol())
2887 && Target_i386::can_convert_mov_to_lea(gsym))))
2890 elfcpp::Elf_types<32>::Elf_Addr value;
2891 value = psymval->value(object, 0);
2892 // Don't subtract the .got.plt section address for baseless
2895 value -= target->got_plt_section()->address();
2896 Relocate_functions<32, false>::rel32(view, value);
2900 // The GOT pointer points to the end of the GOT section.
2901 // We need to subtract the size of the GOT section to get
2902 // the actual offset to use in the relocation.
2903 unsigned int got_offset = 0;
2906 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2907 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2908 - target->got_size());
2912 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2913 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2914 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2915 - target->got_size());
2917 // Add the .got.plt section address for baseless addressing.
2919 got_offset += target->got_plt_section()->address();
2920 Relocate_functions<32, false>::rel32(view, got_offset);
2924 case elfcpp::R_386_GOTOFF:
2926 elfcpp::Elf_types<32>::Elf_Addr value;
2927 value = (psymval->value(object, 0)
2928 - target->got_plt_section()->address());
2929 Relocate_functions<32, false>::rel32(view, value);
2933 case elfcpp::R_386_GOTPC:
2935 elfcpp::Elf_types<32>::Elf_Addr value;
2936 value = target->got_plt_section()->address();
2937 Relocate_functions<32, false>::pcrel32(view, value, address);
2941 case elfcpp::R_386_COPY:
2942 case elfcpp::R_386_GLOB_DAT:
2943 case elfcpp::R_386_JUMP_SLOT:
2944 case elfcpp::R_386_RELATIVE:
2945 case elfcpp::R_386_IRELATIVE:
2946 // These are outstanding tls relocs, which are unexpected when
2948 case elfcpp::R_386_TLS_TPOFF:
2949 case elfcpp::R_386_TLS_DTPMOD32:
2950 case elfcpp::R_386_TLS_DTPOFF32:
2951 case elfcpp::R_386_TLS_TPOFF32:
2952 case elfcpp::R_386_TLS_DESC:
2953 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2954 _("unexpected reloc %u in object file"),
2958 // These are initial tls relocs, which are expected when
2960 case elfcpp::R_386_TLS_GD: // Global-dynamic
2961 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2962 case elfcpp::R_386_TLS_DESC_CALL:
2963 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2964 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2965 case elfcpp::R_386_TLS_IE: // Initial-exec
2966 case elfcpp::R_386_TLS_IE_32:
2967 case elfcpp::R_386_TLS_GOTIE:
2968 case elfcpp::R_386_TLS_LE: // Local-exec
2969 case elfcpp::R_386_TLS_LE_32:
2970 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2971 view, address, view_size);
2974 case elfcpp::R_386_32PLT:
2975 case elfcpp::R_386_TLS_GD_32:
2976 case elfcpp::R_386_TLS_GD_PUSH:
2977 case elfcpp::R_386_TLS_GD_CALL:
2978 case elfcpp::R_386_TLS_GD_POP:
2979 case elfcpp::R_386_TLS_LDM_32:
2980 case elfcpp::R_386_TLS_LDM_PUSH:
2981 case elfcpp::R_386_TLS_LDM_CALL:
2982 case elfcpp::R_386_TLS_LDM_POP:
2983 case elfcpp::R_386_USED_BY_INTEL_200:
2985 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2986 _("unsupported reloc %u"),
2994 // Perform a TLS relocation.
2997 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2998 Target_i386* target,
3000 const elfcpp::Rel<32, false>& rel,
3001 unsigned int r_type,
3002 const Sized_symbol<32>* gsym,
3003 const Symbol_value<32>* psymval,
3004 unsigned char* view,
3005 elfcpp::Elf_types<32>::Elf_Addr,
3006 section_size_type view_size)
3008 Output_segment* tls_segment = relinfo->layout->tls_segment();
3010 const Sized_relobj_file<32, false>* object = relinfo->object;
3012 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
3014 const bool is_final = (gsym == NULL
3015 ? !parameters->options().shared()
3016 : gsym->final_value_is_known());
3017 const tls::Tls_optimization optimized_type
3018 = Target_i386::optimize_tls_reloc(is_final, r_type);
3021 case elfcpp::R_386_TLS_GD: // Global-dynamic
3022 if (optimized_type == tls::TLSOPT_TO_LE)
3024 if (tls_segment == NULL)
3026 gold_assert(parameters->errors()->error_count() > 0
3027 || issue_undefined_symbol_error(gsym));
3030 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3031 rel, r_type, value, view,
3037 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3038 ? GOT_TYPE_TLS_NOFFSET
3039 : GOT_TYPE_TLS_PAIR);
3040 unsigned int got_offset;
3043 gold_assert(gsym->has_got_offset(got_type));
3044 got_offset = gsym->got_offset(got_type) - target->got_size();
3048 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3049 gold_assert(object->local_has_got_offset(r_sym, got_type));
3050 got_offset = (object->local_got_offset(r_sym, got_type)
3051 - target->got_size());
3053 if (optimized_type == tls::TLSOPT_TO_IE)
3055 this->tls_gd_to_ie(relinfo, relnum, rel, r_type,
3056 got_offset, view, view_size);
3059 else if (optimized_type == tls::TLSOPT_NONE)
3061 // Relocate the field with the offset of the pair of GOT
3063 Relocate_functions<32, false>::rel32(view, got_offset);
3067 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3068 _("unsupported reloc %u"),
3072 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3073 case elfcpp::R_386_TLS_DESC_CALL:
3074 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3075 if (optimized_type == tls::TLSOPT_TO_LE)
3077 if (tls_segment == NULL)
3079 gold_assert(parameters->errors()->error_count() > 0
3080 || issue_undefined_symbol_error(gsym));
3083 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3084 rel, r_type, value, view,
3090 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3091 ? GOT_TYPE_TLS_NOFFSET
3092 : GOT_TYPE_TLS_DESC);
3093 unsigned int got_offset = 0;
3094 if (r_type == elfcpp::R_386_TLS_GOTDESC
3095 && optimized_type == tls::TLSOPT_NONE)
3097 // We created GOT entries in the .got.tlsdesc portion of
3098 // the .got.plt section, but the offset stored in the
3099 // symbol is the offset within .got.tlsdesc.
3100 got_offset = (target->got_size()
3101 + target->got_plt_section()->data_size());
3105 gold_assert(gsym->has_got_offset(got_type));
3106 got_offset += gsym->got_offset(got_type) - target->got_size();
3110 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3111 gold_assert(object->local_has_got_offset(r_sym, got_type));
3112 got_offset += (object->local_got_offset(r_sym, got_type)
3113 - target->got_size());
3115 if (optimized_type == tls::TLSOPT_TO_IE)
3117 this->tls_desc_gd_to_ie(relinfo, relnum, rel, r_type,
3118 got_offset, view, view_size);
3121 else if (optimized_type == tls::TLSOPT_NONE)
3123 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3125 // Relocate the field with the offset of the pair of GOT
3127 Relocate_functions<32, false>::rel32(view, got_offset);
3132 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3133 _("unsupported reloc %u"),
3137 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3138 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
3140 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3141 _("both SUN and GNU model "
3142 "TLS relocations"));
3145 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3146 if (optimized_type == tls::TLSOPT_TO_LE)
3148 if (tls_segment == NULL)
3150 gold_assert(parameters->errors()->error_count() > 0
3151 || issue_undefined_symbol_error(gsym));
3154 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
3155 value, view, view_size);
3158 else if (optimized_type == tls::TLSOPT_NONE)
3160 // Relocate the field with the offset of the GOT entry for
3161 // the module index.
3162 unsigned int got_offset;
3163 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3164 - target->got_size());
3165 Relocate_functions<32, false>::rel32(view, got_offset);
3168 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3169 _("unsupported reloc %u"),
3173 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3174 if (optimized_type == tls::TLSOPT_TO_LE)
3176 // This reloc can appear in debugging sections, in which
3177 // case we must not convert to local-exec. We decide what
3178 // to do based on whether the section is marked as
3179 // containing executable code. That is what the GNU linker
3181 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
3182 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
3184 if (tls_segment == NULL)
3186 gold_assert(parameters->errors()->error_count() > 0
3187 || issue_undefined_symbol_error(gsym));
3190 value -= tls_segment->memsz();
3193 Relocate_functions<32, false>::rel32(view, value);
3196 case elfcpp::R_386_TLS_IE: // Initial-exec
3197 case elfcpp::R_386_TLS_GOTIE:
3198 case elfcpp::R_386_TLS_IE_32:
3199 if (optimized_type == tls::TLSOPT_TO_LE)
3201 if (tls_segment == NULL)
3203 gold_assert(parameters->errors()->error_count() > 0
3204 || issue_undefined_symbol_error(gsym));
3207 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3208 rel, r_type, value, view,
3212 else if (optimized_type == tls::TLSOPT_NONE)
3214 // Relocate the field with the offset of the GOT entry for
3215 // the tp-relative offset of the symbol.
3216 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
3217 ? GOT_TYPE_TLS_OFFSET
3218 : GOT_TYPE_TLS_NOFFSET);
3219 unsigned int got_offset;
3222 gold_assert(gsym->has_got_offset(got_type));
3223 got_offset = gsym->got_offset(got_type);
3227 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3228 gold_assert(object->local_has_got_offset(r_sym, got_type));
3229 got_offset = object->local_got_offset(r_sym, got_type);
3231 // For the R_386_TLS_IE relocation, we need to apply the
3232 // absolute address of the GOT entry.
3233 if (r_type == elfcpp::R_386_TLS_IE)
3234 got_offset += target->got_plt_section()->address();
3235 // All GOT offsets are relative to the end of the GOT.
3236 got_offset -= target->got_size();
3237 Relocate_functions<32, false>::rel32(view, got_offset);
3240 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3241 _("unsupported reloc %u"),
3245 case elfcpp::R_386_TLS_LE: // Local-exec
3246 // If we're creating a shared library, a dynamic relocation will
3247 // have been created for this location, so do not apply it now.
3248 if (!parameters->options().shared())
3250 if (tls_segment == NULL)
3252 gold_assert(parameters->errors()->error_count() > 0
3253 || issue_undefined_symbol_error(gsym));
3256 value -= tls_segment->memsz();
3257 Relocate_functions<32, false>::rel32(view, value);
3261 case elfcpp::R_386_TLS_LE_32:
3262 // If we're creating a shared library, a dynamic relocation will
3263 // have been created for this location, so do not apply it now.
3264 if (!parameters->options().shared())
3266 if (tls_segment == NULL)
3268 gold_assert(parameters->errors()->error_count() > 0
3269 || issue_undefined_symbol_error(gsym));
3272 value = tls_segment->memsz() - value;
3273 Relocate_functions<32, false>::rel32(view, value);
3279 // Do a relocation in which we convert a TLS General-Dynamic to a
3283 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
3285 Output_segment* tls_segment,
3286 const elfcpp::Rel<32, false>& rel,
3288 elfcpp::Elf_types<32>::Elf_Addr value,
3289 unsigned char* view,
3290 section_size_type view_size)
3292 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3293 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3294 // leal foo(%reg),%eax; call ___tls_get_addr
3295 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3297 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3298 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3300 unsigned char op1 = view[-1];
3301 unsigned char op2 = view[-2];
3303 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3304 op2 == 0x8d || op2 == 0x04);
3305 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3311 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3312 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3313 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3314 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3315 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3319 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3320 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3321 if (rel.get_r_offset() + 9 < view_size
3324 // There is a trailing nop. Use the size byte subl.
3325 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3330 // Use the five byte subl.
3331 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3335 value = tls_segment->memsz() - value;
3336 Relocate_functions<32, false>::rel32(view + roff, value);
3338 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3340 this->skip_call_tls_get_addr_ = true;
3343 // Do a relocation in which we convert a TLS General-Dynamic to an
3347 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3349 const elfcpp::Rel<32, false>& rel,
3351 elfcpp::Elf_types<32>::Elf_Addr value,
3352 unsigned char* view,
3353 section_size_type view_size)
3355 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3356 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3357 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3358 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3360 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3361 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3363 unsigned char op1 = view[-1];
3364 unsigned char op2 = view[-2];
3366 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3367 op2 == 0x8d || op2 == 0x04);
3368 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3374 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3375 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3376 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3377 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3382 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
3383 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3384 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3385 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[9] == 0x90);
3389 memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3390 Relocate_functions<32, false>::rel32(view + roff, value);
3392 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3394 this->skip_call_tls_get_addr_ = true;
3397 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3398 // General-Dynamic to a Local-Exec.
3401 Target_i386::Relocate::tls_desc_gd_to_le(
3402 const Relocate_info<32, false>* relinfo,
3404 Output_segment* tls_segment,
3405 const elfcpp::Rel<32, false>& rel,
3406 unsigned int r_type,
3407 elfcpp::Elf_types<32>::Elf_Addr value,
3408 unsigned char* view,
3409 section_size_type view_size)
3411 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3413 // leal foo@TLSDESC(%ebx), %eax
3414 // ==> leal foo@NTPOFF, %eax
3415 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3416 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3417 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3418 view[-2] == 0x8d && view[-1] == 0x83);
3420 value -= tls_segment->memsz();
3421 Relocate_functions<32, false>::rel32(view, value);
3425 // call *foo@TLSCALL(%eax)
3427 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3428 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3429 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3430 view[0] == 0xff && view[1] == 0x10);
3436 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3437 // General-Dynamic to an Initial-Exec.
3440 Target_i386::Relocate::tls_desc_gd_to_ie(
3441 const Relocate_info<32, false>* relinfo,
3443 const elfcpp::Rel<32, false>& rel,
3444 unsigned int r_type,
3445 elfcpp::Elf_types<32>::Elf_Addr value,
3446 unsigned char* view,
3447 section_size_type view_size)
3449 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3451 // leal foo@TLSDESC(%ebx), %eax
3452 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3453 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3454 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3455 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3456 view[-2] == 0x8d && view[-1] == 0x83);
3458 Relocate_functions<32, false>::rel32(view, value);
3462 // call *foo@TLSCALL(%eax)
3464 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3465 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3466 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3467 view[0] == 0xff && view[1] == 0x10);
3473 // Do a relocation in which we convert a TLS Local-Dynamic to a
3477 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3480 const elfcpp::Rel<32, false>& rel,
3482 elfcpp::Elf_types<32>::Elf_Addr,
3483 unsigned char* view,
3484 section_size_type view_size)
3486 // leal foo(%reg), %eax; call ___tls_get_addr
3487 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3489 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3490 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3492 // FIXME: Does this test really always pass?
3493 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3494 view[-2] == 0x8d && view[-1] == 0x83);
3496 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3498 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3500 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3502 this->skip_call_tls_get_addr_ = true;
3505 // Do a relocation in which we convert a TLS Initial-Exec to a
3509 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3511 Output_segment* tls_segment,
3512 const elfcpp::Rel<32, false>& rel,
3513 unsigned int r_type,
3514 elfcpp::Elf_types<32>::Elf_Addr value,
3515 unsigned char* view,
3516 section_size_type view_size)
3518 // We have to actually change the instructions, which means that we
3519 // need to examine the opcodes to figure out which instruction we
3521 if (r_type == elfcpp::R_386_TLS_IE)
3523 // movl %gs:XX,%eax ==> movl $YY,%eax
3524 // movl %gs:XX,%reg ==> movl $YY,%reg
3525 // addl %gs:XX,%reg ==> addl $YY,%reg
3526 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3527 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3529 unsigned char op1 = view[-1];
3532 // movl XX,%eax ==> movl $YY,%eax
3537 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3539 unsigned char op2 = view[-2];
3542 // movl XX,%reg ==> movl $YY,%reg
3543 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3544 (op1 & 0xc7) == 0x05);
3546 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3548 else if (op2 == 0x03)
3550 // addl XX,%reg ==> addl $YY,%reg
3551 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3552 (op1 & 0xc7) == 0x05);
3554 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3557 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3562 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3563 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3564 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3565 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3566 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3568 unsigned char op1 = view[-1];
3569 unsigned char op2 = view[-2];
3570 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3571 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3574 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3576 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3578 else if (op2 == 0x2b)
3580 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3582 view[-1] = 0xe8 | ((op1 >> 3) & 7);
3584 else if (op2 == 0x03)
3586 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3588 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3591 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3594 value = tls_segment->memsz() - value;
3595 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3598 Relocate_functions<32, false>::rel32(view, value);
3601 // Relocate section data.
3604 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3605 unsigned int sh_type,
3606 const unsigned char* prelocs,
3608 Output_section* output_section,
3609 bool needs_special_offset_handling,
3610 unsigned char* view,
3611 elfcpp::Elf_types<32>::Elf_Addr address,
3612 section_size_type view_size,
3613 const Reloc_symbol_changes* reloc_symbol_changes)
3615 gold_assert(sh_type == elfcpp::SHT_REL);
3617 gold::relocate_section<32, false, Target_i386, Relocate,
3618 gold::Default_comdat_behavior, Classify_reloc>(
3624 needs_special_offset_handling,
3628 reloc_symbol_changes);
3631 // Return the size of a relocation while scanning during a relocatable
3635 Target_i386::Classify_reloc::get_size_for_reloc(
3636 unsigned int r_type,
3641 case elfcpp::R_386_NONE:
3642 case elfcpp::R_386_GNU_VTINHERIT:
3643 case elfcpp::R_386_GNU_VTENTRY:
3644 case elfcpp::R_386_TLS_GD: // Global-dynamic
3645 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3646 case elfcpp::R_386_TLS_DESC_CALL:
3647 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3648 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3649 case elfcpp::R_386_TLS_IE: // Initial-exec
3650 case elfcpp::R_386_TLS_IE_32:
3651 case elfcpp::R_386_TLS_GOTIE:
3652 case elfcpp::R_386_TLS_LE: // Local-exec
3653 case elfcpp::R_386_TLS_LE_32:
3656 case elfcpp::R_386_32:
3657 case elfcpp::R_386_PC32:
3658 case elfcpp::R_386_GOT32:
3659 case elfcpp::R_386_GOT32X:
3660 case elfcpp::R_386_PLT32:
3661 case elfcpp::R_386_GOTOFF:
3662 case elfcpp::R_386_GOTPC:
3665 case elfcpp::R_386_16:
3666 case elfcpp::R_386_PC16:
3669 case elfcpp::R_386_8:
3670 case elfcpp::R_386_PC8:
3673 // These are relocations which should only be seen by the
3674 // dynamic linker, and should never be seen here.
3675 case elfcpp::R_386_COPY:
3676 case elfcpp::R_386_GLOB_DAT:
3677 case elfcpp::R_386_JUMP_SLOT:
3678 case elfcpp::R_386_RELATIVE:
3679 case elfcpp::R_386_IRELATIVE:
3680 case elfcpp::R_386_TLS_TPOFF:
3681 case elfcpp::R_386_TLS_DTPMOD32:
3682 case elfcpp::R_386_TLS_DTPOFF32:
3683 case elfcpp::R_386_TLS_TPOFF32:
3684 case elfcpp::R_386_TLS_DESC:
3685 object->error(_("unexpected reloc %u in object file"), r_type);
3688 case elfcpp::R_386_32PLT:
3689 case elfcpp::R_386_TLS_GD_32:
3690 case elfcpp::R_386_TLS_GD_PUSH:
3691 case elfcpp::R_386_TLS_GD_CALL:
3692 case elfcpp::R_386_TLS_GD_POP:
3693 case elfcpp::R_386_TLS_LDM_32:
3694 case elfcpp::R_386_TLS_LDM_PUSH:
3695 case elfcpp::R_386_TLS_LDM_CALL:
3696 case elfcpp::R_386_TLS_LDM_POP:
3697 case elfcpp::R_386_USED_BY_INTEL_200:
3699 object->error(_("unsupported reloc %u in object file"), r_type);
3704 // Scan the relocs during a relocatable link.
3707 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3709 Sized_relobj_file<32, false>* object,
3710 unsigned int data_shndx,
3711 unsigned int sh_type,
3712 const unsigned char* prelocs,
3714 Output_section* output_section,
3715 bool needs_special_offset_handling,
3716 size_t local_symbol_count,
3717 const unsigned char* plocal_symbols,
3718 Relocatable_relocs* rr)
3720 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
3721 Scan_relocatable_relocs;
3723 gold_assert(sh_type == elfcpp::SHT_REL);
3725 gold::scan_relocatable_relocs<32, false, Scan_relocatable_relocs>(
3733 needs_special_offset_handling,
3739 // Scan the relocs for --emit-relocs.
3742 Target_i386::emit_relocs_scan(Symbol_table* symtab,
3744 Sized_relobj_file<32, false>* object,
3745 unsigned int data_shndx,
3746 unsigned int sh_type,
3747 const unsigned char* prelocs,
3749 Output_section* output_section,
3750 bool needs_special_offset_handling,
3751 size_t local_symbol_count,
3752 const unsigned char* plocal_syms,
3753 Relocatable_relocs* rr)
3755 typedef gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
3757 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
3758 Emit_relocs_strategy;
3760 gold_assert(sh_type == elfcpp::SHT_REL);
3762 gold::scan_relocatable_relocs<32, false, Emit_relocs_strategy>(
3770 needs_special_offset_handling,
3776 // Emit relocations for a section.
3779 Target_i386::relocate_relocs(
3780 const Relocate_info<32, false>* relinfo,
3781 unsigned int sh_type,
3782 const unsigned char* prelocs,
3784 Output_section* output_section,
3785 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
3786 unsigned char* view,
3787 elfcpp::Elf_types<32>::Elf_Addr view_address,
3788 section_size_type view_size,
3789 unsigned char* reloc_view,
3790 section_size_type reloc_view_size)
3792 gold_assert(sh_type == elfcpp::SHT_REL);
3794 gold::relocate_relocs<32, false, Classify_reloc>(
3799 offset_in_output_section,
3807 // Return the value to use for a dynamic which requires special
3808 // treatment. This is how we support equality comparisons of function
3809 // pointers across shared library boundaries, as described in the
3810 // processor specific ABI supplement.
3813 Target_i386::do_dynsym_value(const Symbol* gsym) const
3815 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3816 return this->plt_address_for_global(gsym);
3819 // Return a string used to fill a code section with nops to take up
3820 // the specified length.
3823 Target_i386::do_code_fill(section_size_type length) const
3827 // Build a jmp instruction to skip over the bytes.
3828 unsigned char jmp[5];
3830 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3831 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3832 + std::string(length - 5, static_cast<char>(0x90)));
3835 // Nop sequences of various lengths.
3836 const char nop1[1] = { '\x90' }; // nop
3837 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
3838 const char nop3[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3839 const char nop4[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3841 const char nop5[5] = { '\x90', '\x8d', '\x74', // nop
3842 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3843 const char nop6[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3844 '\x00', '\x00', '\x00' };
3845 const char nop7[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3846 '\x00', '\x00', '\x00',
3848 const char nop8[8] = { '\x90', '\x8d', '\xb4', // nop
3849 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3851 const char nop9[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3852 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3853 '\x00', '\x00', '\x00' };
3854 const char nop10[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3855 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3856 '\x00', '\x00', '\x00',
3858 const char nop11[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3859 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3860 '\x27', '\x00', '\x00',
3862 const char nop12[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3863 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3864 '\x8d', '\xbf', '\x00',
3865 '\x00', '\x00', '\x00' };
3866 const char nop13[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3867 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3868 '\x8d', '\xbc', '\x27',
3869 '\x00', '\x00', '\x00',
3871 const char nop14[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3872 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3873 '\x00', '\x8d', '\xbc',
3874 '\x27', '\x00', '\x00',
3876 const char nop15[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3877 '\x90', '\x90', '\x90', // nop,nop,nop,...
3878 '\x90', '\x90', '\x90',
3879 '\x90', '\x90', '\x90',
3880 '\x90', '\x90', '\x90' };
3882 const char* nops[16] = {
3884 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3885 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3888 return std::string(nops[length], length);
3891 // Return the value to use for the base of a DW_EH_PE_datarel offset
3892 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3893 // assembler can not write out the difference between two labels in
3894 // different sections, so instead of using a pc-relative value they
3895 // use an offset from the GOT.
3898 Target_i386::do_ehframe_datarel_base() const
3900 gold_assert(this->global_offset_table_ != NULL);
3901 Symbol* sym = this->global_offset_table_;
3902 Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3903 return ssym->value();
3906 // Return whether SYM should be treated as a call to a non-split
3907 // function. We don't want that to be true of a call to a
3908 // get_pc_thunk function.
3911 Target_i386::do_is_call_to_non_split(const Symbol* sym,
3912 const unsigned char*) const
3914 return (sym->type() == elfcpp::STT_FUNC
3915 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3918 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3919 // compiled with -fsplit-stack. The function calls non-split-stack
3920 // code. We have to change the function so that it always ensures
3921 // that it has enough stack space to run some random function.
3924 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3925 section_offset_type fnoffset,
3926 section_size_type fnsize,
3927 const unsigned char*,
3929 unsigned char* view,
3930 section_size_type view_size,
3932 std::string* to) const
3934 // The function starts with a comparison of the stack pointer and a
3935 // field in the TCB. This is followed by a jump.
3938 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3941 // We will call __morestack if the carry flag is set after this
3942 // comparison. We turn the comparison into an stc instruction
3944 view[fnoffset] = '\xf9';
3945 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3947 // lea NN(%esp),%ecx
3948 // lea NN(%esp),%edx
3949 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3950 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3953 // This is loading an offset from the stack pointer for a
3954 // comparison. The offset is negative, so we decrease the
3955 // offset by the amount of space we need for the stack. This
3956 // means we will avoid calling __morestack if there happens to
3957 // be plenty of space on the stack already.
3958 unsigned char* pval = view + fnoffset + 3;
3959 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3960 val -= parameters->options().split_stack_adjust_size();
3961 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3965 if (!object->has_no_split_stack())
3966 object->error(_("failed to match split-stack sequence at "
3967 "section %u offset %0zx"),
3968 shndx, static_cast<size_t>(fnoffset));
3972 // We have to change the function so that it calls
3973 // __morestack_non_split instead of __morestack. The former will
3974 // allocate additional stack space.
3975 *from = "__morestack";
3976 *to = "__morestack_non_split";
3979 // The selector for i386 object files. Note this is never instantiated
3980 // directly. It's only used in Target_selector_i386_nacl, below.
3982 class Target_selector_i386 : public Target_selector_freebsd
3985 Target_selector_i386()
3986 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3987 "elf32-i386", "elf32-i386-freebsd",
3992 do_instantiate_target()
3993 { return new Target_i386(); }
3996 // NaCl variant. It uses different PLT contents.
3998 class Output_data_plt_i386_nacl : public Output_data_plt_i386
4001 Output_data_plt_i386_nacl(Layout* layout,
4002 Output_data_got_plt_i386* got_plt,
4003 Output_data_space* got_irelative)
4004 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
4008 virtual unsigned int
4009 do_get_plt_entry_size() const
4010 { return plt_entry_size; }
4013 do_add_eh_frame(Layout* layout)
4015 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
4016 plt_eh_frame_fde, plt_eh_frame_fde_size);
4019 // The size of an entry in the PLT.
4020 static const int plt_entry_size = 64;
4022 // The .eh_frame unwind information for the PLT.
4023 static const int plt_eh_frame_fde_size = 32;
4024 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4027 class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
4030 Output_data_plt_i386_nacl_exec(Layout* layout,
4031 Output_data_got_plt_i386* got_plt,
4032 Output_data_space* got_irelative)
4033 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4038 do_fill_first_plt_entry(unsigned char* pov,
4039 elfcpp::Elf_types<32>::Elf_Addr got_address);
4041 virtual unsigned int
4042 do_fill_plt_entry(unsigned char* pov,
4043 elfcpp::Elf_types<32>::Elf_Addr got_address,
4044 unsigned int got_offset,
4045 unsigned int plt_offset,
4046 unsigned int plt_rel_offset);
4049 // The first entry in the PLT for an executable.
4050 static const unsigned char first_plt_entry[plt_entry_size];
4052 // Other entries in the PLT for an executable.
4053 static const unsigned char plt_entry[plt_entry_size];
4056 class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
4059 Output_data_plt_i386_nacl_dyn(Layout* layout,
4060 Output_data_got_plt_i386* got_plt,
4061 Output_data_space* got_irelative)
4062 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4067 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
4069 virtual unsigned int
4070 do_fill_plt_entry(unsigned char* pov,
4071 elfcpp::Elf_types<32>::Elf_Addr,
4072 unsigned int got_offset,
4073 unsigned int plt_offset,
4074 unsigned int plt_rel_offset);
4077 // The first entry in the PLT for a shared object.
4078 static const unsigned char first_plt_entry[plt_entry_size];
4080 // Other entries in the PLT for a shared object.
4081 static const unsigned char plt_entry[plt_entry_size];
4084 class Target_i386_nacl : public Target_i386
4088 : Target_i386(&i386_nacl_info)
4092 virtual Output_data_plt_i386*
4093 do_make_data_plt(Layout* layout,
4094 Output_data_got_plt_i386* got_plt,
4095 Output_data_space* got_irelative,
4099 return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
4101 return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
4105 do_code_fill(section_size_type length) const;
4108 static const Target::Target_info i386_nacl_info;
4111 const Target::Target_info Target_i386_nacl::i386_nacl_info =
4114 false, // is_big_endian
4115 elfcpp::EM_386, // machine_code
4116 false, // has_make_symbol
4117 false, // has_resolve
4118 true, // has_code_fill
4119 true, // is_default_stack_executable
4120 true, // can_icf_inline_merge_sections
4122 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4123 0x20000, // default_text_segment_address
4124 0x10000, // abi_pagesize (overridable by -z max-page-size)
4125 0x10000, // common_pagesize (overridable by -z common-page-size)
4126 true, // isolate_execinstr
4127 0x10000000, // rosegment_gap
4128 elfcpp::SHN_UNDEF, // small_common_shndx
4129 elfcpp::SHN_UNDEF, // large_common_shndx
4130 0, // small_common_section_flags
4131 0, // large_common_section_flags
4132 NULL, // attributes_section
4133 NULL, // attributes_vendor
4134 "_start", // entry_symbol_name
4135 32, // hash_entry_size
4138 #define NACLMASK 0xe0 // 32-byte alignment mask
4141 Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
4143 0xff, 0x35, // pushl contents of memory address
4144 0, 0, 0, 0, // replaced with address of .got + 4
4145 0x8b, 0x0d, // movl contents of address, %ecx
4146 0, 0, 0, 0, // replaced with address of .got + 8
4147 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4148 0xff, 0xe1, // jmp *%ecx
4149 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4150 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4151 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4152 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4153 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4154 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4155 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4156 0x90, 0x90, 0x90, 0x90, 0x90
4160 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4162 elfcpp::Elf_types<32>::Elf_Addr got_address)
4164 memcpy(pov, first_plt_entry, plt_entry_size);
4165 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
4166 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
4169 // The first entry in the PLT for a shared object.
4172 Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
4174 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4175 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4176 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4177 0xff, 0xe1, // jmp *%ecx
4178 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4179 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4180 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4181 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4182 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4183 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4184 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4185 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4186 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4187 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4191 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4193 elfcpp::Elf_types<32>::Elf_Addr)
4195 memcpy(pov, first_plt_entry, plt_entry_size);
4198 // Subsequent entries in the PLT for an executable.
4201 Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
4203 0x8b, 0x0d, // movl contents of address, %ecx */
4204 0, 0, 0, 0, // replaced with address of symbol in .got
4205 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4206 0xff, 0xe1, // jmp *%ecx
4208 // Pad to the next 32-byte boundary with nop instructions.
4210 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4211 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4213 // Lazy GOT entries point here (32-byte aligned).
4214 0x68, // pushl immediate
4215 0, 0, 0, 0, // replaced with offset into relocation table
4216 0xe9, // jmp relative
4217 0, 0, 0, 0, // replaced with offset to start of .plt
4219 // 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,
4226 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4228 elfcpp::Elf_types<32>::Elf_Addr got_address,
4229 unsigned int got_offset,
4230 unsigned int plt_offset,
4231 unsigned int plt_rel_offset)
4233 memcpy(pov, plt_entry, plt_entry_size);
4234 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4235 got_address + got_offset);
4236 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4237 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4241 // Subsequent entries in the PLT for a shared object.
4244 Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
4246 0x8b, 0x8b, // movl offset(%ebx), %ecx
4247 0, 0, 0, 0, // replaced with offset of symbol in .got
4248 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4249 0xff, 0xe1, // jmp *%ecx
4251 // Pad to the next 32-byte boundary with nop instructions.
4253 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4254 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4256 // Lazy GOT entries point here (32-byte aligned).
4257 0x68, // pushl immediate
4258 0, 0, 0, 0, // replaced with offset into relocation table.
4259 0xe9, // jmp relative
4260 0, 0, 0, 0, // replaced with offset to start of .plt.
4262 // 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,
4269 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4271 elfcpp::Elf_types<32>::Elf_Addr,
4272 unsigned int got_offset,
4273 unsigned int plt_offset,
4274 unsigned int plt_rel_offset)
4276 memcpy(pov, plt_entry, plt_entry_size);
4277 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
4278 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4279 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4284 Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4286 0, 0, 0, 0, // Replaced with offset to .plt.
4287 0, 0, 0, 0, // Replaced with size of .plt.
4288 0, // Augmentation size.
4289 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
4290 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4291 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
4292 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4293 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4294 13, // Block length.
4295 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
4296 elfcpp::DW_OP_breg8, 0, // Push %eip.
4297 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4298 elfcpp::DW_OP_and, // & (%eip & 0x3f).
4299 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4300 elfcpp::DW_OP_ge, // >= ((%eip & 0x3f) >= 0x25)
4301 elfcpp::DW_OP_lit2, // Push 2.
4302 elfcpp::DW_OP_shl, // << (((%eip & 0x3f) >= 0x25) << 2)
4303 elfcpp::DW_OP_plus, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4304 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4308 // Return a string used to fill a code section with nops.
4309 // For NaCl, long NOPs are only valid if they do not cross
4310 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4312 Target_i386_nacl::do_code_fill(section_size_type length) const
4314 return std::string(length, static_cast<char>(0x90));
4317 // The selector for i386-nacl object files.
4319 class Target_selector_i386_nacl
4320 : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
4323 Target_selector_i386_nacl()
4324 : Target_selector_nacl<Target_selector_i386,
4325 Target_i386_nacl>("x86-32",
4331 Target_selector_i386_nacl target_selector_i386;
4333 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4335 class Target_iamcu : public Target_i386
4339 : Target_i386(&iamcu_info)
4343 // Information about this specific target which we pass to the
4344 // general Target structure.
4345 static const Target::Target_info iamcu_info;
4348 const Target::Target_info Target_iamcu::iamcu_info =
4351 false, // is_big_endian
4352 elfcpp::EM_IAMCU, // machine_code
4353 false, // has_make_symbol
4354 false, // has_resolve
4355 true, // has_code_fill
4356 true, // is_default_stack_executable
4357 true, // can_icf_inline_merge_sections
4359 "/usr/lib/libc.so.1", // dynamic_linker
4360 0x08048000, // default_text_segment_address
4361 0x1000, // abi_pagesize (overridable by -z max-page-size)
4362 0x1000, // common_pagesize (overridable by -z common-page-size)
4363 false, // isolate_execinstr
4365 elfcpp::SHN_UNDEF, // small_common_shndx
4366 elfcpp::SHN_UNDEF, // large_common_shndx
4367 0, // small_common_section_flags
4368 0, // large_common_section_flags
4369 NULL, // attributes_section
4370 NULL, // attributes_vendor
4371 "_start", // entry_symbol_name
4372 32, // hash_entry_size
4375 class Target_selector_iamcu : public Target_selector
4378 Target_selector_iamcu()
4379 : Target_selector(elfcpp::EM_IAMCU, 32, false, "elf32-iamcu",
4384 do_instantiate_target()
4385 { return new Target_iamcu(); }
4388 Target_selector_iamcu target_selector_iamcu;
4390 } // End anonymous namespace.