1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009 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.
28 #include "parameters.h"
35 #include "copy-relocs.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
48 class Output_data_plt_i386;
50 // The i386 target class.
51 // TLS info comes from
52 // http://people.redhat.com/drepper/tls.pdf
53 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
55 class Target_i386 : public Target_freebsd<32, false>
58 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
61 : Target_freebsd<32, false>(&i386_info),
62 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
63 copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
64 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
67 // Process the relocations to determine unreferenced sections for
68 // garbage collection.
70 gc_process_relocs(Symbol_table* symtab,
72 Sized_relobj<32, false>* object,
73 unsigned int data_shndx,
75 const unsigned char* prelocs,
77 Output_section* output_section,
78 bool needs_special_offset_handling,
79 size_t local_symbol_count,
80 const unsigned char* plocal_symbols);
82 // Scan the relocations to look for symbol adjustments.
84 scan_relocs(Symbol_table* symtab,
86 Sized_relobj<32, false>* object,
87 unsigned int data_shndx,
89 const unsigned char* prelocs,
91 Output_section* output_section,
92 bool needs_special_offset_handling,
93 size_t local_symbol_count,
94 const unsigned char* plocal_symbols);
96 // Finalize the sections.
98 do_finalize_sections(Layout*);
100 // Return the value to use for a dynamic which requires special
103 do_dynsym_value(const Symbol*) const;
105 // Relocate a section.
107 relocate_section(const Relocate_info<32, false>*,
108 unsigned int sh_type,
109 const unsigned char* prelocs,
111 Output_section* output_section,
112 bool needs_special_offset_handling,
114 elfcpp::Elf_types<32>::Elf_Addr view_address,
115 section_size_type view_size,
116 const Reloc_symbol_changes*);
118 // Scan the relocs during a relocatable link.
120 scan_relocatable_relocs(Symbol_table* symtab,
122 Sized_relobj<32, false>* object,
123 unsigned int data_shndx,
124 unsigned int sh_type,
125 const unsigned char* prelocs,
127 Output_section* output_section,
128 bool needs_special_offset_handling,
129 size_t local_symbol_count,
130 const unsigned char* plocal_symbols,
131 Relocatable_relocs*);
133 // Relocate a section during a relocatable link.
135 relocate_for_relocatable(const Relocate_info<32, false>*,
136 unsigned int sh_type,
137 const unsigned char* prelocs,
139 Output_section* output_section,
140 off_t offset_in_output_section,
141 const Relocatable_relocs*,
143 elfcpp::Elf_types<32>::Elf_Addr view_address,
144 section_size_type view_size,
145 unsigned char* reloc_view,
146 section_size_type reloc_view_size);
148 // Return a string used to fill a code section with nops.
150 do_code_fill(section_size_type length) const;
152 // Return whether SYM is defined by the ABI.
154 do_is_defined_by_abi(const Symbol* sym) const
155 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
157 // Return whether a symbol name implies a local label. The UnixWare
158 // 2.1 cc generates temporary symbols that start with .X, so we
159 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
160 // If so, we should move the .X recognition into
161 // Target::do_is_local_label_name.
163 do_is_local_label_name(const char* name) const
165 if (name[0] == '.' && name[1] == 'X')
167 return Target::do_is_local_label_name(name);
170 // Adjust -fstack-split code which calls non-stack-split code.
172 do_calls_non_split(Relobj* object, unsigned int shndx,
173 section_offset_type fnoffset, section_size_type fnsize,
174 unsigned char* view, section_size_type view_size,
175 std::string* from, std::string* to) const;
177 // Return the size of the GOT section.
181 gold_assert(this->got_ != NULL);
182 return this->got_->data_size();
186 // The class which scans relocations.
190 local(Symbol_table* symtab, Layout* layout, Target_i386* target,
191 Sized_relobj<32, false>* object,
192 unsigned int data_shndx,
193 Output_section* output_section,
194 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
195 const elfcpp::Sym<32, false>& lsym);
198 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
199 Sized_relobj<32, false>* object,
200 unsigned int data_shndx,
201 Output_section* output_section,
202 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
206 unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
209 unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
213 // The class which implements relocation.
218 : skip_call_tls_get_addr_(false),
219 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
224 if (this->skip_call_tls_get_addr_)
226 // FIXME: This needs to specify the location somehow.
227 gold_error(_("missing expected TLS relocation"));
231 // Return whether the static relocation needs to be applied.
233 should_apply_static_reloc(const Sized_symbol<32>* gsym,
236 Output_section* output_section);
238 // Do a relocation. Return false if the caller should not issue
239 // any warnings about this relocation.
241 relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
242 size_t relnum, const elfcpp::Rel<32, false>&,
243 unsigned int r_type, const Sized_symbol<32>*,
244 const Symbol_value<32>*,
245 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
249 // Do a TLS relocation.
251 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
252 size_t relnum, const elfcpp::Rel<32, false>&,
253 unsigned int r_type, const Sized_symbol<32>*,
254 const Symbol_value<32>*,
255 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
258 // Do a TLS General-Dynamic to Initial-Exec transition.
260 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
261 Output_segment* tls_segment,
262 const elfcpp::Rel<32, false>&, unsigned int r_type,
263 elfcpp::Elf_types<32>::Elf_Addr value,
265 section_size_type view_size);
267 // Do a TLS General-Dynamic to Local-Exec transition.
269 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
270 Output_segment* tls_segment,
271 const elfcpp::Rel<32, false>&, unsigned int r_type,
272 elfcpp::Elf_types<32>::Elf_Addr value,
274 section_size_type view_size);
276 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
279 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
280 Output_segment* tls_segment,
281 const elfcpp::Rel<32, false>&, unsigned int r_type,
282 elfcpp::Elf_types<32>::Elf_Addr value,
284 section_size_type view_size);
286 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
289 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
290 Output_segment* tls_segment,
291 const elfcpp::Rel<32, false>&, unsigned int r_type,
292 elfcpp::Elf_types<32>::Elf_Addr value,
294 section_size_type view_size);
296 // Do a TLS Local-Dynamic to Local-Exec transition.
298 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
299 Output_segment* tls_segment,
300 const elfcpp::Rel<32, false>&, unsigned int r_type,
301 elfcpp::Elf_types<32>::Elf_Addr value,
303 section_size_type view_size);
305 // Do a TLS Initial-Exec to Local-Exec transition.
307 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
308 Output_segment* tls_segment,
309 const elfcpp::Rel<32, false>&, unsigned int r_type,
310 elfcpp::Elf_types<32>::Elf_Addr value,
312 section_size_type view_size);
314 // We need to keep track of which type of local dynamic relocation
315 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
316 enum Local_dynamic_type
323 // This is set if we should skip the next reloc, which should be a
324 // PLT32 reloc against ___tls_get_addr.
325 bool skip_call_tls_get_addr_;
326 // The type of local dynamic relocation we have seen in the section
327 // being relocated, if any.
328 Local_dynamic_type local_dynamic_type_;
331 // A class which returns the size required for a relocation type,
332 // used while scanning relocs during a relocatable link.
333 class Relocatable_size_for_reloc
337 get_size_for_reloc(unsigned int, Relobj*);
340 // Adjust TLS relocation type based on the options and whether this
341 // is a local symbol.
342 static tls::Tls_optimization
343 optimize_tls_reloc(bool is_final, int r_type);
345 // Get the GOT section, creating it if necessary.
346 Output_data_got<32, false>*
347 got_section(Symbol_table*, Layout*);
349 // Get the GOT PLT section.
351 got_plt_section() const
353 gold_assert(this->got_plt_ != NULL);
354 return this->got_plt_;
357 // Create a PLT entry for a global symbol.
359 make_plt_entry(Symbol_table*, Layout*, Symbol*);
361 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
363 define_tls_base_symbol(Symbol_table*, Layout*);
365 // Create a GOT entry for the TLS module index.
367 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
368 Sized_relobj<32, false>* object);
370 // Get the PLT section.
371 const Output_data_plt_i386*
374 gold_assert(this->plt_ != NULL);
378 // Get the dynamic reloc section, creating it if necessary.
380 rel_dyn_section(Layout*);
382 // Add a potential copy relocation.
384 copy_reloc(Symbol_table* symtab, Layout* layout,
385 Sized_relobj<32, false>* object,
386 unsigned int shndx, Output_section* output_section,
387 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
389 this->copy_relocs_.copy_reloc(symtab, layout,
390 symtab->get_sized_symbol<32>(sym),
391 object, shndx, output_section, reloc,
392 this->rel_dyn_section(layout));
395 // Information about this specific target which we pass to the
396 // general Target structure.
397 static const Target::Target_info i386_info;
399 // The types of GOT entries needed for this platform.
402 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
403 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
404 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
405 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
406 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
410 Output_data_got<32, false>* got_;
412 Output_data_plt_i386* plt_;
413 // The GOT PLT section.
414 Output_data_space* got_plt_;
415 // The dynamic reloc section.
416 Reloc_section* rel_dyn_;
417 // Relocs saved to avoid a COPY reloc.
418 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
419 // Space for variables copied with a COPY reloc.
420 Output_data_space* dynbss_;
421 // Offset of the GOT entry for the TLS module index.
422 unsigned int got_mod_index_offset_;
423 // True if the _TLS_MODULE_BASE_ symbol has been defined.
424 bool tls_base_symbol_defined_;
427 const Target::Target_info Target_i386::i386_info =
430 false, // is_big_endian
431 elfcpp::EM_386, // machine_code
432 false, // has_make_symbol
433 false, // has_resolve
434 true, // has_code_fill
435 true, // is_default_stack_executable
437 "/usr/lib/libc.so.1", // dynamic_linker
438 0x08048000, // default_text_segment_address
439 0x1000, // abi_pagesize (overridable by -z max-page-size)
440 0x1000, // common_pagesize (overridable by -z common-page-size)
441 elfcpp::SHN_UNDEF, // small_common_shndx
442 elfcpp::SHN_UNDEF, // large_common_shndx
443 0, // small_common_section_flags
444 0 // large_common_section_flags
447 // Get the GOT section, creating it if necessary.
449 Output_data_got<32, false>*
450 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
452 if (this->got_ == NULL)
454 gold_assert(symtab != NULL && layout != NULL);
456 this->got_ = new Output_data_got<32, false>();
459 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
461 | elfcpp::SHF_WRITE),
465 // The old GNU linker creates a .got.plt section. We just
466 // create another set of data in the .got section. Note that we
467 // always create a PLT if we create a GOT, although the PLT
469 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
470 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
472 | elfcpp::SHF_WRITE),
476 // The first three entries are reserved.
477 this->got_plt_->set_current_data_size(3 * 4);
479 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
480 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
482 0, 0, elfcpp::STT_OBJECT,
484 elfcpp::STV_HIDDEN, 0,
491 // Get the dynamic reloc section, creating it if necessary.
493 Target_i386::Reloc_section*
494 Target_i386::rel_dyn_section(Layout* layout)
496 if (this->rel_dyn_ == NULL)
498 gold_assert(layout != NULL);
499 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
500 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
501 elfcpp::SHF_ALLOC, this->rel_dyn_);
503 return this->rel_dyn_;
506 // A class to handle the PLT data.
508 class Output_data_plt_i386 : public Output_section_data
511 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
513 Output_data_plt_i386(Layout*, Output_data_space*);
515 // Add an entry to the PLT.
517 add_entry(Symbol* gsym);
519 // Return the .rel.plt section data.
522 { return this->rel_; }
526 do_adjust_output_section(Output_section* os);
528 // Write to a map file.
530 do_print_to_mapfile(Mapfile* mapfile) const
531 { mapfile->print_output_data(this, _("** PLT")); }
534 // The size of an entry in the PLT.
535 static const int plt_entry_size = 16;
537 // The first entry in the PLT for an executable.
538 static unsigned char exec_first_plt_entry[plt_entry_size];
540 // The first entry in the PLT for a shared object.
541 static unsigned char dyn_first_plt_entry[plt_entry_size];
543 // Other entries in the PLT for an executable.
544 static unsigned char exec_plt_entry[plt_entry_size];
546 // Other entries in the PLT for a shared object.
547 static unsigned char dyn_plt_entry[plt_entry_size];
549 // Set the final size.
551 set_final_data_size()
552 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
554 // Write out the PLT data.
556 do_write(Output_file*);
558 // The reloc section.
560 // The .got.plt section.
561 Output_data_space* got_plt_;
562 // The number of PLT entries.
566 // Create the PLT section. The ordinary .got section is an argument,
567 // since we need to refer to the start. We also create our own .got
568 // section just for PLT entries.
570 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
571 Output_data_space* got_plt)
572 : Output_section_data(4), got_plt_(got_plt), count_(0)
574 this->rel_ = new Reloc_section(false);
575 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
576 elfcpp::SHF_ALLOC, this->rel_);
580 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
582 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
583 // linker, and so do we.
587 // Add an entry to the PLT.
590 Output_data_plt_i386::add_entry(Symbol* gsym)
592 gold_assert(!gsym->has_plt_offset());
594 // Note that when setting the PLT offset we skip the initial
595 // reserved PLT entry.
596 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
600 section_offset_type got_offset = this->got_plt_->current_data_size();
602 // Every PLT entry needs a GOT entry which points back to the PLT
603 // entry (this will be changed by the dynamic linker, normally
604 // lazily when the function is called).
605 this->got_plt_->set_current_data_size(got_offset + 4);
607 // Every PLT entry needs a reloc.
608 gsym->set_needs_dynsym_entry();
609 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
612 // Note that we don't need to save the symbol. The contents of the
613 // PLT are independent of which symbols are used. The symbols only
614 // appear in the relocations.
617 // The first entry in the PLT for an executable.
619 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
621 0xff, 0x35, // pushl contents of memory address
622 0, 0, 0, 0, // replaced with address of .got + 4
623 0xff, 0x25, // jmp indirect
624 0, 0, 0, 0, // replaced with address of .got + 8
628 // The first entry in the PLT for a shared object.
630 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
632 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
633 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
637 // Subsequent entries in the PLT for an executable.
639 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
641 0xff, 0x25, // jmp indirect
642 0, 0, 0, 0, // replaced with address of symbol in .got
643 0x68, // pushl immediate
644 0, 0, 0, 0, // replaced with offset into relocation table
645 0xe9, // jmp relative
646 0, 0, 0, 0 // replaced with offset to start of .plt
649 // Subsequent entries in the PLT for a shared object.
651 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
653 0xff, 0xa3, // jmp *offset(%ebx)
654 0, 0, 0, 0, // replaced with offset of symbol in .got
655 0x68, // pushl immediate
656 0, 0, 0, 0, // replaced with offset into relocation table
657 0xe9, // jmp relative
658 0, 0, 0, 0 // replaced with offset to start of .plt
661 // Write out the PLT. This uses the hand-coded instructions above,
662 // and adjusts them as needed. This is all specified by the i386 ELF
663 // Processor Supplement.
666 Output_data_plt_i386::do_write(Output_file* of)
668 const off_t offset = this->offset();
669 const section_size_type oview_size =
670 convert_to_section_size_type(this->data_size());
671 unsigned char* const oview = of->get_output_view(offset, oview_size);
673 const off_t got_file_offset = this->got_plt_->offset();
674 const section_size_type got_size =
675 convert_to_section_size_type(this->got_plt_->data_size());
676 unsigned char* const got_view = of->get_output_view(got_file_offset,
679 unsigned char* pov = oview;
681 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
682 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
684 if (parameters->options().output_is_position_independent())
685 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
688 memcpy(pov, exec_first_plt_entry, plt_entry_size);
689 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
690 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
692 pov += plt_entry_size;
694 unsigned char* got_pov = got_view;
696 memset(got_pov, 0, 12);
699 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
701 unsigned int plt_offset = plt_entry_size;
702 unsigned int plt_rel_offset = 0;
703 unsigned int got_offset = 12;
704 const unsigned int count = this->count_;
705 for (unsigned int i = 0;
708 pov += plt_entry_size,
710 plt_offset += plt_entry_size,
711 plt_rel_offset += rel_size,
714 // Set and adjust the PLT entry itself.
716 if (parameters->options().output_is_position_independent())
718 memcpy(pov, dyn_plt_entry, plt_entry_size);
719 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
723 memcpy(pov, exec_plt_entry, plt_entry_size);
724 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
729 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
730 elfcpp::Swap<32, false>::writeval(pov + 12,
731 - (plt_offset + plt_entry_size));
733 // Set the entry in the GOT.
734 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
737 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
738 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
740 of->write_output_view(offset, oview_size, oview);
741 of->write_output_view(got_file_offset, got_size, got_view);
744 // Create a PLT entry for a global symbol.
747 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
749 if (gsym->has_plt_offset())
752 if (this->plt_ == NULL)
754 // Create the GOT sections first.
755 this->got_section(symtab, layout);
757 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
758 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
760 | elfcpp::SHF_EXECINSTR),
764 this->plt_->add_entry(gsym);
767 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
770 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
772 if (this->tls_base_symbol_defined_)
775 Output_segment* tls_segment = layout->tls_segment();
776 if (tls_segment != NULL)
778 bool is_exec = parameters->options().output_is_executable();
779 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
783 elfcpp::STV_HIDDEN, 0,
785 ? Symbol::SEGMENT_END
786 : Symbol::SEGMENT_START),
789 this->tls_base_symbol_defined_ = true;
792 // Create a GOT entry for the TLS module index.
795 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
796 Sized_relobj<32, false>* object)
798 if (this->got_mod_index_offset_ == -1U)
800 gold_assert(symtab != NULL && layout != NULL && object != NULL);
801 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
802 Output_data_got<32, false>* got = this->got_section(symtab, layout);
803 unsigned int got_offset = got->add_constant(0);
804 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
806 got->add_constant(0);
807 this->got_mod_index_offset_ = got_offset;
809 return this->got_mod_index_offset_;
812 // Optimize the TLS relocation type based on what we know about the
813 // symbol. IS_FINAL is true if the final address of this symbol is
814 // known at link time.
816 tls::Tls_optimization
817 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
819 // If we are generating a shared library, then we can't do anything
821 if (parameters->options().shared())
822 return tls::TLSOPT_NONE;
826 case elfcpp::R_386_TLS_GD:
827 case elfcpp::R_386_TLS_GOTDESC:
828 case elfcpp::R_386_TLS_DESC_CALL:
829 // These are General-Dynamic which permits fully general TLS
830 // access. Since we know that we are generating an executable,
831 // we can convert this to Initial-Exec. If we also know that
832 // this is a local symbol, we can further switch to Local-Exec.
834 return tls::TLSOPT_TO_LE;
835 return tls::TLSOPT_TO_IE;
837 case elfcpp::R_386_TLS_LDM:
838 // This is Local-Dynamic, which refers to a local symbol in the
839 // dynamic TLS block. Since we know that we generating an
840 // executable, we can switch to Local-Exec.
841 return tls::TLSOPT_TO_LE;
843 case elfcpp::R_386_TLS_LDO_32:
844 // Another type of Local-Dynamic relocation.
845 return tls::TLSOPT_TO_LE;
847 case elfcpp::R_386_TLS_IE:
848 case elfcpp::R_386_TLS_GOTIE:
849 case elfcpp::R_386_TLS_IE_32:
850 // These are Initial-Exec relocs which get the thread offset
851 // from the GOT. If we know that we are linking against the
852 // local symbol, we can switch to Local-Exec, which links the
853 // thread offset into the instruction.
855 return tls::TLSOPT_TO_LE;
856 return tls::TLSOPT_NONE;
858 case elfcpp::R_386_TLS_LE:
859 case elfcpp::R_386_TLS_LE_32:
860 // When we already have Local-Exec, there is nothing further we
862 return tls::TLSOPT_NONE;
869 // Report an unsupported relocation against a local symbol.
872 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
875 gold_error(_("%s: unsupported reloc %u against local symbol"),
876 object->name().c_str(), r_type);
879 // Scan a relocation for a local symbol.
882 Target_i386::Scan::local(Symbol_table* symtab,
885 Sized_relobj<32, false>* object,
886 unsigned int data_shndx,
887 Output_section* output_section,
888 const elfcpp::Rel<32, false>& reloc,
890 const elfcpp::Sym<32, false>& lsym)
894 case elfcpp::R_386_NONE:
895 case elfcpp::R_386_GNU_VTINHERIT:
896 case elfcpp::R_386_GNU_VTENTRY:
899 case elfcpp::R_386_32:
900 // If building a shared library (or a position-independent
901 // executable), we need to create a dynamic relocation for
902 // this location. The relocation applied at link time will
903 // apply the link-time value, so we flag the location with
904 // an R_386_RELATIVE relocation so the dynamic loader can
905 // relocate it easily.
906 if (parameters->options().output_is_position_independent())
908 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
909 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
910 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
911 output_section, data_shndx,
912 reloc.get_r_offset());
916 case elfcpp::R_386_16:
917 case elfcpp::R_386_8:
918 // If building a shared library (or a position-independent
919 // executable), we need to create a dynamic relocation for
920 // this location. Because the addend needs to remain in the
921 // data section, we need to be careful not to apply this
922 // relocation statically.
923 if (parameters->options().output_is_position_independent())
925 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
926 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
927 if (lsym.get_st_type() != elfcpp::STT_SECTION)
928 rel_dyn->add_local(object, r_sym, r_type, output_section,
929 data_shndx, reloc.get_r_offset());
932 gold_assert(lsym.get_st_value() == 0);
933 unsigned int shndx = lsym.get_st_shndx();
935 shndx = object->adjust_sym_shndx(r_sym, shndx,
938 object->error(_("section symbol %u has bad shndx %u"),
941 rel_dyn->add_local_section(object, shndx,
942 r_type, output_section,
943 data_shndx, reloc.get_r_offset());
948 case elfcpp::R_386_PC32:
949 case elfcpp::R_386_PC16:
950 case elfcpp::R_386_PC8:
953 case elfcpp::R_386_PLT32:
954 // Since we know this is a local symbol, we can handle this as a
958 case elfcpp::R_386_GOTOFF:
959 case elfcpp::R_386_GOTPC:
960 // We need a GOT section.
961 target->got_section(symtab, layout);
964 case elfcpp::R_386_GOT32:
966 // The symbol requires a GOT entry.
967 Output_data_got<32, false>* got = target->got_section(symtab, layout);
968 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
969 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
971 // If we are generating a shared object, we need to add a
972 // dynamic RELATIVE relocation for this symbol's GOT entry.
973 if (parameters->options().output_is_position_independent())
975 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
976 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
977 rel_dyn->add_local_relative(
978 object, r_sym, elfcpp::R_386_RELATIVE, got,
979 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
985 // These are relocations which should only be seen by the
986 // dynamic linker, and should never be seen here.
987 case elfcpp::R_386_COPY:
988 case elfcpp::R_386_GLOB_DAT:
989 case elfcpp::R_386_JUMP_SLOT:
990 case elfcpp::R_386_RELATIVE:
991 case elfcpp::R_386_TLS_TPOFF:
992 case elfcpp::R_386_TLS_DTPMOD32:
993 case elfcpp::R_386_TLS_DTPOFF32:
994 case elfcpp::R_386_TLS_TPOFF32:
995 case elfcpp::R_386_TLS_DESC:
996 gold_error(_("%s: unexpected reloc %u in object file"),
997 object->name().c_str(), r_type);
1000 // These are initial TLS relocs, which are expected when
1002 case elfcpp::R_386_TLS_GD: // Global-dynamic
1003 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1004 case elfcpp::R_386_TLS_DESC_CALL:
1005 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1006 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1007 case elfcpp::R_386_TLS_IE: // Initial-exec
1008 case elfcpp::R_386_TLS_IE_32:
1009 case elfcpp::R_386_TLS_GOTIE:
1010 case elfcpp::R_386_TLS_LE: // Local-exec
1011 case elfcpp::R_386_TLS_LE_32:
1013 bool output_is_shared = parameters->options().shared();
1014 const tls::Tls_optimization optimized_type
1015 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1018 case elfcpp::R_386_TLS_GD: // Global-dynamic
1019 if (optimized_type == tls::TLSOPT_NONE)
1021 // Create a pair of GOT entries for the module index and
1022 // dtv-relative offset.
1023 Output_data_got<32, false>* got
1024 = target->got_section(symtab, layout);
1025 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1026 unsigned int shndx = lsym.get_st_shndx();
1028 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1030 object->error(_("local symbol %u has bad shndx %u"),
1033 got->add_local_pair_with_rel(object, r_sym, shndx,
1035 target->rel_dyn_section(layout),
1036 elfcpp::R_386_TLS_DTPMOD32, 0);
1038 else if (optimized_type != tls::TLSOPT_TO_LE)
1039 unsupported_reloc_local(object, r_type);
1042 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1043 target->define_tls_base_symbol(symtab, layout);
1044 if (optimized_type == tls::TLSOPT_NONE)
1046 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1047 Output_data_got<32, false>* got
1048 = target->got_section(symtab, layout);
1049 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1050 unsigned int shndx = lsym.get_st_shndx();
1052 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1054 object->error(_("local symbol %u has bad shndx %u"),
1057 got->add_local_pair_with_rel(object, r_sym, shndx,
1059 target->rel_dyn_section(layout),
1060 elfcpp::R_386_TLS_DESC, 0);
1062 else if (optimized_type != tls::TLSOPT_TO_LE)
1063 unsupported_reloc_local(object, r_type);
1066 case elfcpp::R_386_TLS_DESC_CALL:
1069 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1070 if (optimized_type == tls::TLSOPT_NONE)
1072 // Create a GOT entry for the module index.
1073 target->got_mod_index_entry(symtab, layout, object);
1075 else if (optimized_type != tls::TLSOPT_TO_LE)
1076 unsupported_reloc_local(object, r_type);
1079 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1082 case elfcpp::R_386_TLS_IE: // Initial-exec
1083 case elfcpp::R_386_TLS_IE_32:
1084 case elfcpp::R_386_TLS_GOTIE:
1085 layout->set_has_static_tls();
1086 if (optimized_type == tls::TLSOPT_NONE)
1088 // For the R_386_TLS_IE relocation, we need to create a
1089 // dynamic relocation when building a shared library.
1090 if (r_type == elfcpp::R_386_TLS_IE
1091 && parameters->options().shared())
1093 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1095 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1096 rel_dyn->add_local_relative(object, r_sym,
1097 elfcpp::R_386_RELATIVE,
1098 output_section, data_shndx,
1099 reloc.get_r_offset());
1101 // Create a GOT entry for the tp-relative offset.
1102 Output_data_got<32, false>* got
1103 = target->got_section(symtab, layout);
1104 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1105 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1106 ? elfcpp::R_386_TLS_TPOFF32
1107 : elfcpp::R_386_TLS_TPOFF);
1108 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1109 ? GOT_TYPE_TLS_OFFSET
1110 : GOT_TYPE_TLS_NOFFSET);
1111 got->add_local_with_rel(object, r_sym, got_type,
1112 target->rel_dyn_section(layout),
1115 else if (optimized_type != tls::TLSOPT_TO_LE)
1116 unsupported_reloc_local(object, r_type);
1119 case elfcpp::R_386_TLS_LE: // Local-exec
1120 case elfcpp::R_386_TLS_LE_32:
1121 layout->set_has_static_tls();
1122 if (output_is_shared)
1124 // We need to create a dynamic relocation.
1125 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1126 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1127 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1128 ? elfcpp::R_386_TLS_TPOFF32
1129 : elfcpp::R_386_TLS_TPOFF);
1130 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1131 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1132 data_shndx, reloc.get_r_offset());
1142 case elfcpp::R_386_32PLT:
1143 case elfcpp::R_386_TLS_GD_32:
1144 case elfcpp::R_386_TLS_GD_PUSH:
1145 case elfcpp::R_386_TLS_GD_CALL:
1146 case elfcpp::R_386_TLS_GD_POP:
1147 case elfcpp::R_386_TLS_LDM_32:
1148 case elfcpp::R_386_TLS_LDM_PUSH:
1149 case elfcpp::R_386_TLS_LDM_CALL:
1150 case elfcpp::R_386_TLS_LDM_POP:
1151 case elfcpp::R_386_USED_BY_INTEL_200:
1153 unsupported_reloc_local(object, r_type);
1158 // Report an unsupported relocation against a global symbol.
1161 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1162 unsigned int r_type,
1165 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1166 object->name().c_str(), r_type, gsym->demangled_name().c_str());
1169 // Scan a relocation for a global symbol.
1172 Target_i386::Scan::global(Symbol_table* symtab,
1174 Target_i386* target,
1175 Sized_relobj<32, false>* object,
1176 unsigned int data_shndx,
1177 Output_section* output_section,
1178 const elfcpp::Rel<32, false>& reloc,
1179 unsigned int r_type,
1184 case elfcpp::R_386_NONE:
1185 case elfcpp::R_386_GNU_VTINHERIT:
1186 case elfcpp::R_386_GNU_VTENTRY:
1189 case elfcpp::R_386_32:
1190 case elfcpp::R_386_16:
1191 case elfcpp::R_386_8:
1193 // Make a PLT entry if necessary.
1194 if (gsym->needs_plt_entry())
1196 target->make_plt_entry(symtab, layout, gsym);
1197 // Since this is not a PC-relative relocation, we may be
1198 // taking the address of a function. In that case we need to
1199 // set the entry in the dynamic symbol table to the address of
1201 if (gsym->is_from_dynobj() && !parameters->options().shared())
1202 gsym->set_needs_dynsym_value();
1204 // Make a dynamic relocation if necessary.
1205 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1207 if (gsym->may_need_copy_reloc())
1209 target->copy_reloc(symtab, layout, object,
1210 data_shndx, output_section, gsym, reloc);
1212 else if (r_type == elfcpp::R_386_32
1213 && gsym->can_use_relative_reloc(false))
1215 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1216 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1217 output_section, object,
1218 data_shndx, reloc.get_r_offset());
1222 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1223 rel_dyn->add_global(gsym, r_type, output_section, object,
1224 data_shndx, reloc.get_r_offset());
1230 case elfcpp::R_386_PC32:
1231 case elfcpp::R_386_PC16:
1232 case elfcpp::R_386_PC8:
1234 // Make a PLT entry if necessary.
1235 if (gsym->needs_plt_entry())
1237 // These relocations are used for function calls only in
1238 // non-PIC code. For a 32-bit relocation in a shared library,
1239 // we'll need a text relocation anyway, so we can skip the
1240 // PLT entry and let the dynamic linker bind the call directly
1241 // to the target. For smaller relocations, we should use a
1242 // PLT entry to ensure that the call can reach.
1243 if (!parameters->options().shared()
1244 || r_type != elfcpp::R_386_PC32)
1245 target->make_plt_entry(symtab, layout, gsym);
1247 // Make a dynamic relocation if necessary.
1248 int flags = Symbol::NON_PIC_REF;
1249 if (gsym->type() == elfcpp::STT_FUNC)
1250 flags |= Symbol::FUNCTION_CALL;
1251 if (gsym->needs_dynamic_reloc(flags))
1253 if (gsym->may_need_copy_reloc())
1255 target->copy_reloc(symtab, layout, object,
1256 data_shndx, output_section, gsym, reloc);
1260 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1261 rel_dyn->add_global(gsym, r_type, output_section, object,
1262 data_shndx, reloc.get_r_offset());
1268 case elfcpp::R_386_GOT32:
1270 // The symbol requires a GOT entry.
1271 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1272 if (gsym->final_value_is_known())
1273 got->add_global(gsym, GOT_TYPE_STANDARD);
1276 // If this symbol is not fully resolved, we need to add a
1277 // GOT entry with a dynamic relocation.
1278 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1279 if (gsym->is_from_dynobj()
1280 || gsym->is_undefined()
1281 || gsym->is_preemptible())
1282 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1283 rel_dyn, elfcpp::R_386_GLOB_DAT);
1286 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1287 rel_dyn->add_global_relative(
1288 gsym, elfcpp::R_386_RELATIVE, got,
1289 gsym->got_offset(GOT_TYPE_STANDARD));
1295 case elfcpp::R_386_PLT32:
1296 // If the symbol is fully resolved, this is just a PC32 reloc.
1297 // Otherwise we need a PLT entry.
1298 if (gsym->final_value_is_known())
1300 // If building a shared library, we can also skip the PLT entry
1301 // if the symbol is defined in the output file and is protected
1303 if (gsym->is_defined()
1304 && !gsym->is_from_dynobj()
1305 && !gsym->is_preemptible())
1307 target->make_plt_entry(symtab, layout, gsym);
1310 case elfcpp::R_386_GOTOFF:
1311 case elfcpp::R_386_GOTPC:
1312 // We need a GOT section.
1313 target->got_section(symtab, layout);
1316 // These are relocations which should only be seen by the
1317 // dynamic linker, and should never be seen here.
1318 case elfcpp::R_386_COPY:
1319 case elfcpp::R_386_GLOB_DAT:
1320 case elfcpp::R_386_JUMP_SLOT:
1321 case elfcpp::R_386_RELATIVE:
1322 case elfcpp::R_386_TLS_TPOFF:
1323 case elfcpp::R_386_TLS_DTPMOD32:
1324 case elfcpp::R_386_TLS_DTPOFF32:
1325 case elfcpp::R_386_TLS_TPOFF32:
1326 case elfcpp::R_386_TLS_DESC:
1327 gold_error(_("%s: unexpected reloc %u in object file"),
1328 object->name().c_str(), r_type);
1331 // These are initial tls relocs, which are expected when
1333 case elfcpp::R_386_TLS_GD: // Global-dynamic
1334 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1335 case elfcpp::R_386_TLS_DESC_CALL:
1336 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1337 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1338 case elfcpp::R_386_TLS_IE: // Initial-exec
1339 case elfcpp::R_386_TLS_IE_32:
1340 case elfcpp::R_386_TLS_GOTIE:
1341 case elfcpp::R_386_TLS_LE: // Local-exec
1342 case elfcpp::R_386_TLS_LE_32:
1344 const bool is_final = gsym->final_value_is_known();
1345 const tls::Tls_optimization optimized_type
1346 = Target_i386::optimize_tls_reloc(is_final, r_type);
1349 case elfcpp::R_386_TLS_GD: // Global-dynamic
1350 if (optimized_type == tls::TLSOPT_NONE)
1352 // Create a pair of GOT entries for the module index and
1353 // dtv-relative offset.
1354 Output_data_got<32, false>* got
1355 = target->got_section(symtab, layout);
1356 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1357 target->rel_dyn_section(layout),
1358 elfcpp::R_386_TLS_DTPMOD32,
1359 elfcpp::R_386_TLS_DTPOFF32);
1361 else if (optimized_type == tls::TLSOPT_TO_IE)
1363 // Create a GOT entry for the tp-relative offset.
1364 Output_data_got<32, false>* got
1365 = target->got_section(symtab, layout);
1366 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1367 target->rel_dyn_section(layout),
1368 elfcpp::R_386_TLS_TPOFF);
1370 else if (optimized_type != tls::TLSOPT_TO_LE)
1371 unsupported_reloc_global(object, r_type, gsym);
1374 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
1375 target->define_tls_base_symbol(symtab, layout);
1376 if (optimized_type == tls::TLSOPT_NONE)
1378 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1379 Output_data_got<32, false>* got
1380 = target->got_section(symtab, layout);
1381 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
1382 target->rel_dyn_section(layout),
1383 elfcpp::R_386_TLS_DESC, 0);
1385 else if (optimized_type == tls::TLSOPT_TO_IE)
1387 // Create a GOT entry for the tp-relative offset.
1388 Output_data_got<32, false>* got
1389 = target->got_section(symtab, layout);
1390 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1391 target->rel_dyn_section(layout),
1392 elfcpp::R_386_TLS_TPOFF);
1394 else if (optimized_type != tls::TLSOPT_TO_LE)
1395 unsupported_reloc_global(object, r_type, gsym);
1398 case elfcpp::R_386_TLS_DESC_CALL:
1401 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1402 if (optimized_type == tls::TLSOPT_NONE)
1404 // Create a GOT entry for the module index.
1405 target->got_mod_index_entry(symtab, layout, object);
1407 else if (optimized_type != tls::TLSOPT_TO_LE)
1408 unsupported_reloc_global(object, r_type, gsym);
1411 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1414 case elfcpp::R_386_TLS_IE: // Initial-exec
1415 case elfcpp::R_386_TLS_IE_32:
1416 case elfcpp::R_386_TLS_GOTIE:
1417 layout->set_has_static_tls();
1418 if (optimized_type == tls::TLSOPT_NONE)
1420 // For the R_386_TLS_IE relocation, we need to create a
1421 // dynamic relocation when building a shared library.
1422 if (r_type == elfcpp::R_386_TLS_IE
1423 && parameters->options().shared())
1425 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1426 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1427 output_section, object,
1429 reloc.get_r_offset());
1431 // Create a GOT entry for the tp-relative offset.
1432 Output_data_got<32, false>* got
1433 = target->got_section(symtab, layout);
1434 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1435 ? elfcpp::R_386_TLS_TPOFF32
1436 : elfcpp::R_386_TLS_TPOFF);
1437 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1438 ? GOT_TYPE_TLS_OFFSET
1439 : GOT_TYPE_TLS_NOFFSET);
1440 got->add_global_with_rel(gsym, got_type,
1441 target->rel_dyn_section(layout),
1444 else if (optimized_type != tls::TLSOPT_TO_LE)
1445 unsupported_reloc_global(object, r_type, gsym);
1448 case elfcpp::R_386_TLS_LE: // Local-exec
1449 case elfcpp::R_386_TLS_LE_32:
1450 layout->set_has_static_tls();
1451 if (parameters->options().shared())
1453 // We need to create a dynamic relocation.
1454 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1455 ? elfcpp::R_386_TLS_TPOFF32
1456 : elfcpp::R_386_TLS_TPOFF);
1457 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1458 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1459 data_shndx, reloc.get_r_offset());
1469 case elfcpp::R_386_32PLT:
1470 case elfcpp::R_386_TLS_GD_32:
1471 case elfcpp::R_386_TLS_GD_PUSH:
1472 case elfcpp::R_386_TLS_GD_CALL:
1473 case elfcpp::R_386_TLS_GD_POP:
1474 case elfcpp::R_386_TLS_LDM_32:
1475 case elfcpp::R_386_TLS_LDM_PUSH:
1476 case elfcpp::R_386_TLS_LDM_CALL:
1477 case elfcpp::R_386_TLS_LDM_POP:
1478 case elfcpp::R_386_USED_BY_INTEL_200:
1480 unsupported_reloc_global(object, r_type, gsym);
1485 // Process relocations for gc.
1488 Target_i386::gc_process_relocs(Symbol_table* symtab,
1490 Sized_relobj<32, false>* object,
1491 unsigned int data_shndx,
1493 const unsigned char* prelocs,
1495 Output_section* output_section,
1496 bool needs_special_offset_handling,
1497 size_t local_symbol_count,
1498 const unsigned char* plocal_symbols)
1500 gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1510 needs_special_offset_handling,
1515 // Scan relocations for a section.
1518 Target_i386::scan_relocs(Symbol_table* symtab,
1520 Sized_relobj<32, false>* object,
1521 unsigned int data_shndx,
1522 unsigned int sh_type,
1523 const unsigned char* prelocs,
1525 Output_section* output_section,
1526 bool needs_special_offset_handling,
1527 size_t local_symbol_count,
1528 const unsigned char* plocal_symbols)
1530 if (sh_type == elfcpp::SHT_RELA)
1532 gold_error(_("%s: unsupported RELA reloc section"),
1533 object->name().c_str());
1537 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1547 needs_special_offset_handling,
1552 // Finalize the sections.
1555 Target_i386::do_finalize_sections(Layout* layout)
1557 // Fill in some more dynamic tags.
1558 Output_data_dynamic* const odyn = layout->dynamic_data();
1561 if (this->got_plt_ != NULL)
1562 odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1564 if (this->plt_ != NULL)
1566 const Output_data* od = this->plt_->rel_plt();
1567 odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1568 odyn->add_section_address(elfcpp::DT_JMPREL, od);
1569 odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1572 if (this->rel_dyn_ != NULL)
1574 const Output_data* od = this->rel_dyn_;
1575 odyn->add_section_address(elfcpp::DT_REL, od);
1576 odyn->add_section_size(elfcpp::DT_RELSZ, od);
1577 odyn->add_constant(elfcpp::DT_RELENT,
1578 elfcpp::Elf_sizes<32>::rel_size);
1581 if (!parameters->options().shared())
1583 // The value of the DT_DEBUG tag is filled in by the dynamic
1584 // linker at run time, and used by the debugger.
1585 odyn->add_constant(elfcpp::DT_DEBUG, 0);
1589 // Emit any relocs we saved in an attempt to avoid generating COPY
1591 if (this->copy_relocs_.any_saved_relocs())
1592 this->copy_relocs_.emit(this->rel_dyn_section(layout));
1595 // Return whether a direct absolute static relocation needs to be applied.
1596 // In cases where Scan::local() or Scan::global() has created
1597 // a dynamic relocation other than R_386_RELATIVE, the addend
1598 // of the relocation is carried in the data, and we must not
1599 // apply the static relocation.
1602 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1605 Output_section* output_section)
1607 // If the output section is not allocated, then we didn't call
1608 // scan_relocs, we didn't create a dynamic reloc, and we must apply
1610 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1613 // For local symbols, we will have created a non-RELATIVE dynamic
1614 // relocation only if (a) the output is position independent,
1615 // (b) the relocation is absolute (not pc- or segment-relative), and
1616 // (c) the relocation is not 32 bits wide.
1618 return !(parameters->options().output_is_position_independent()
1619 && (ref_flags & Symbol::ABSOLUTE_REF)
1622 // For global symbols, we use the same helper routines used in the
1623 // scan pass. If we did not create a dynamic relocation, or if we
1624 // created a RELATIVE dynamic relocation, we should apply the static
1626 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1627 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1628 && gsym->can_use_relative_reloc(ref_flags
1629 & Symbol::FUNCTION_CALL);
1630 return !has_dyn || is_rel;
1633 // Perform a relocation.
1636 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1637 Target_i386* target,
1638 Output_section *output_section,
1640 const elfcpp::Rel<32, false>& rel,
1641 unsigned int r_type,
1642 const Sized_symbol<32>* gsym,
1643 const Symbol_value<32>* psymval,
1644 unsigned char* view,
1645 elfcpp::Elf_types<32>::Elf_Addr address,
1646 section_size_type view_size)
1648 if (this->skip_call_tls_get_addr_)
1650 if ((r_type != elfcpp::R_386_PLT32
1651 && r_type != elfcpp::R_386_PC32)
1653 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1654 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1655 _("missing expected TLS relocation"));
1658 this->skip_call_tls_get_addr_ = false;
1663 // Pick the value to use for symbols defined in shared objects.
1664 Symbol_value<32> symval;
1666 && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1667 || r_type == elfcpp::R_386_PC16
1668 || r_type == elfcpp::R_386_PC32))
1670 symval.set_output_value(target->plt_section()->address()
1671 + gsym->plt_offset());
1675 const Sized_relobj<32, false>* object = relinfo->object;
1677 // Get the GOT offset if needed.
1678 // The GOT pointer points to the end of the GOT section.
1679 // We need to subtract the size of the GOT section to get
1680 // the actual offset to use in the relocation.
1681 bool have_got_offset = false;
1682 unsigned int got_offset = 0;
1685 case elfcpp::R_386_GOT32:
1688 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1689 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1690 - target->got_size());
1694 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1695 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1696 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1697 - target->got_size());
1699 have_got_offset = true;
1708 case elfcpp::R_386_NONE:
1709 case elfcpp::R_386_GNU_VTINHERIT:
1710 case elfcpp::R_386_GNU_VTENTRY:
1713 case elfcpp::R_386_32:
1714 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1716 Relocate_functions<32, false>::rel32(view, object, psymval);
1719 case elfcpp::R_386_PC32:
1721 int ref_flags = Symbol::NON_PIC_REF;
1722 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1723 ref_flags |= Symbol::FUNCTION_CALL;
1724 if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1725 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1729 case elfcpp::R_386_16:
1730 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1732 Relocate_functions<32, false>::rel16(view, object, psymval);
1735 case elfcpp::R_386_PC16:
1737 int ref_flags = Symbol::NON_PIC_REF;
1738 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1739 ref_flags |= Symbol::FUNCTION_CALL;
1740 if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1741 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1745 case elfcpp::R_386_8:
1746 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1748 Relocate_functions<32, false>::rel8(view, object, psymval);
1751 case elfcpp::R_386_PC8:
1753 int ref_flags = Symbol::NON_PIC_REF;
1754 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1755 ref_flags |= Symbol::FUNCTION_CALL;
1756 if (should_apply_static_reloc(gsym, ref_flags, false,
1758 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1762 case elfcpp::R_386_PLT32:
1763 gold_assert(gsym == NULL
1764 || gsym->has_plt_offset()
1765 || gsym->final_value_is_known()
1766 || (gsym->is_defined()
1767 && !gsym->is_from_dynobj()
1768 && !gsym->is_preemptible()));
1769 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1772 case elfcpp::R_386_GOT32:
1773 gold_assert(have_got_offset);
1774 Relocate_functions<32, false>::rel32(view, got_offset);
1777 case elfcpp::R_386_GOTOFF:
1779 elfcpp::Elf_types<32>::Elf_Addr value;
1780 value = (psymval->value(object, 0)
1781 - target->got_plt_section()->address());
1782 Relocate_functions<32, false>::rel32(view, value);
1786 case elfcpp::R_386_GOTPC:
1788 elfcpp::Elf_types<32>::Elf_Addr value;
1789 value = target->got_plt_section()->address();
1790 Relocate_functions<32, false>::pcrel32(view, value, address);
1794 case elfcpp::R_386_COPY:
1795 case elfcpp::R_386_GLOB_DAT:
1796 case elfcpp::R_386_JUMP_SLOT:
1797 case elfcpp::R_386_RELATIVE:
1798 // These are outstanding tls relocs, which are unexpected when
1800 case elfcpp::R_386_TLS_TPOFF:
1801 case elfcpp::R_386_TLS_DTPMOD32:
1802 case elfcpp::R_386_TLS_DTPOFF32:
1803 case elfcpp::R_386_TLS_TPOFF32:
1804 case elfcpp::R_386_TLS_DESC:
1805 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1806 _("unexpected reloc %u in object file"),
1810 // These are initial tls relocs, which are expected when
1812 case elfcpp::R_386_TLS_GD: // Global-dynamic
1813 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1814 case elfcpp::R_386_TLS_DESC_CALL:
1815 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1816 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1817 case elfcpp::R_386_TLS_IE: // Initial-exec
1818 case elfcpp::R_386_TLS_IE_32:
1819 case elfcpp::R_386_TLS_GOTIE:
1820 case elfcpp::R_386_TLS_LE: // Local-exec
1821 case elfcpp::R_386_TLS_LE_32:
1822 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1823 view, address, view_size);
1826 case elfcpp::R_386_32PLT:
1827 case elfcpp::R_386_TLS_GD_32:
1828 case elfcpp::R_386_TLS_GD_PUSH:
1829 case elfcpp::R_386_TLS_GD_CALL:
1830 case elfcpp::R_386_TLS_GD_POP:
1831 case elfcpp::R_386_TLS_LDM_32:
1832 case elfcpp::R_386_TLS_LDM_PUSH:
1833 case elfcpp::R_386_TLS_LDM_CALL:
1834 case elfcpp::R_386_TLS_LDM_POP:
1835 case elfcpp::R_386_USED_BY_INTEL_200:
1837 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1838 _("unsupported reloc %u"),
1846 // Perform a TLS relocation.
1849 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1850 Target_i386* target,
1852 const elfcpp::Rel<32, false>& rel,
1853 unsigned int r_type,
1854 const Sized_symbol<32>* gsym,
1855 const Symbol_value<32>* psymval,
1856 unsigned char* view,
1857 elfcpp::Elf_types<32>::Elf_Addr,
1858 section_size_type view_size)
1860 Output_segment* tls_segment = relinfo->layout->tls_segment();
1862 const Sized_relobj<32, false>* object = relinfo->object;
1864 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1866 const bool is_final =
1868 ? !parameters->options().output_is_position_independent()
1869 : gsym->final_value_is_known());
1870 const tls::Tls_optimization optimized_type
1871 = Target_i386::optimize_tls_reloc(is_final, r_type);
1874 case elfcpp::R_386_TLS_GD: // Global-dynamic
1875 if (optimized_type == tls::TLSOPT_TO_LE)
1877 gold_assert(tls_segment != NULL);
1878 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1879 rel, r_type, value, view,
1885 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1886 ? GOT_TYPE_TLS_NOFFSET
1887 : GOT_TYPE_TLS_PAIR);
1888 unsigned int got_offset;
1891 gold_assert(gsym->has_got_offset(got_type));
1892 got_offset = gsym->got_offset(got_type) - target->got_size();
1896 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1897 gold_assert(object->local_has_got_offset(r_sym, got_type));
1898 got_offset = (object->local_got_offset(r_sym, got_type)
1899 - target->got_size());
1901 if (optimized_type == tls::TLSOPT_TO_IE)
1903 gold_assert(tls_segment != NULL);
1904 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1905 got_offset, view, view_size);
1908 else if (optimized_type == tls::TLSOPT_NONE)
1910 // Relocate the field with the offset of the pair of GOT
1912 Relocate_functions<32, false>::rel32(view, got_offset);
1916 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1917 _("unsupported reloc %u"),
1921 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1922 case elfcpp::R_386_TLS_DESC_CALL:
1923 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1924 if (optimized_type == tls::TLSOPT_TO_LE)
1926 gold_assert(tls_segment != NULL);
1927 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
1928 rel, r_type, value, view,
1934 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1935 ? GOT_TYPE_TLS_NOFFSET
1936 : GOT_TYPE_TLS_DESC);
1937 unsigned int got_offset;
1940 gold_assert(gsym->has_got_offset(got_type));
1941 got_offset = gsym->got_offset(got_type) - target->got_size();
1945 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1946 gold_assert(object->local_has_got_offset(r_sym, got_type));
1947 got_offset = (object->local_got_offset(r_sym, got_type)
1948 - target->got_size());
1950 if (optimized_type == tls::TLSOPT_TO_IE)
1952 gold_assert(tls_segment != NULL);
1953 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1954 got_offset, view, view_size);
1957 else if (optimized_type == tls::TLSOPT_NONE)
1959 if (r_type == elfcpp::R_386_TLS_GOTDESC)
1961 // Relocate the field with the offset of the pair of GOT
1963 Relocate_functions<32, false>::rel32(view, got_offset);
1968 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1969 _("unsupported reloc %u"),
1973 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1974 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1976 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1977 _("both SUN and GNU model "
1978 "TLS relocations"));
1981 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1982 if (optimized_type == tls::TLSOPT_TO_LE)
1984 gold_assert(tls_segment != NULL);
1985 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1986 value, view, view_size);
1989 else if (optimized_type == tls::TLSOPT_NONE)
1991 // Relocate the field with the offset of the GOT entry for
1992 // the module index.
1993 unsigned int got_offset;
1994 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
1995 - target->got_size());
1996 Relocate_functions<32, false>::rel32(view, got_offset);
1999 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2000 _("unsupported reloc %u"),
2004 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2005 if (optimized_type == tls::TLSOPT_TO_LE)
2007 // This reloc can appear in debugging sections, in which
2008 // case we must not convert to local-exec. We decide what
2009 // to do based on whether the section is marked as
2010 // containing executable code. That is what the GNU linker
2012 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2013 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2015 gold_assert(tls_segment != NULL);
2016 value -= tls_segment->memsz();
2019 Relocate_functions<32, false>::rel32(view, value);
2022 case elfcpp::R_386_TLS_IE: // Initial-exec
2023 case elfcpp::R_386_TLS_GOTIE:
2024 case elfcpp::R_386_TLS_IE_32:
2025 if (optimized_type == tls::TLSOPT_TO_LE)
2027 gold_assert(tls_segment != NULL);
2028 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2029 rel, r_type, value, view,
2033 else if (optimized_type == tls::TLSOPT_NONE)
2035 // Relocate the field with the offset of the GOT entry for
2036 // the tp-relative offset of the symbol.
2037 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2038 ? GOT_TYPE_TLS_OFFSET
2039 : GOT_TYPE_TLS_NOFFSET);
2040 unsigned int got_offset;
2043 gold_assert(gsym->has_got_offset(got_type));
2044 got_offset = gsym->got_offset(got_type);
2048 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2049 gold_assert(object->local_has_got_offset(r_sym, got_type));
2050 got_offset = object->local_got_offset(r_sym, got_type);
2052 // For the R_386_TLS_IE relocation, we need to apply the
2053 // absolute address of the GOT entry.
2054 if (r_type == elfcpp::R_386_TLS_IE)
2055 got_offset += target->got_plt_section()->address();
2056 // All GOT offsets are relative to the end of the GOT.
2057 got_offset -= target->got_size();
2058 Relocate_functions<32, false>::rel32(view, got_offset);
2061 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2062 _("unsupported reloc %u"),
2066 case elfcpp::R_386_TLS_LE: // Local-exec
2067 // If we're creating a shared library, a dynamic relocation will
2068 // have been created for this location, so do not apply it now.
2069 if (!parameters->options().shared())
2071 gold_assert(tls_segment != NULL);
2072 value -= tls_segment->memsz();
2073 Relocate_functions<32, false>::rel32(view, value);
2077 case elfcpp::R_386_TLS_LE_32:
2078 // If we're creating a shared library, a dynamic relocation will
2079 // have been created for this location, so do not apply it now.
2080 if (!parameters->options().shared())
2082 gold_assert(tls_segment != NULL);
2083 value = tls_segment->memsz() - value;
2084 Relocate_functions<32, false>::rel32(view, value);
2090 // Do a relocation in which we convert a TLS General-Dynamic to a
2094 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2096 Output_segment* tls_segment,
2097 const elfcpp::Rel<32, false>& rel,
2099 elfcpp::Elf_types<32>::Elf_Addr value,
2100 unsigned char* view,
2101 section_size_type view_size)
2103 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2104 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2105 // leal foo(%reg),%eax; call ___tls_get_addr
2106 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2108 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2109 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2111 unsigned char op1 = view[-1];
2112 unsigned char op2 = view[-2];
2114 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2115 op2 == 0x8d || op2 == 0x04);
2116 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2122 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2123 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2124 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2125 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2126 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2130 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2131 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2132 if (rel.get_r_offset() + 9 < view_size
2135 // There is a trailing nop. Use the size byte subl.
2136 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2141 // Use the five byte subl.
2142 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2146 value = tls_segment->memsz() - value;
2147 Relocate_functions<32, false>::rel32(view + roff, value);
2149 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2151 this->skip_call_tls_get_addr_ = true;
2154 // Do a relocation in which we convert a TLS General-Dynamic to an
2158 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2161 const elfcpp::Rel<32, false>& rel,
2163 elfcpp::Elf_types<32>::Elf_Addr value,
2164 unsigned char* view,
2165 section_size_type view_size)
2167 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2168 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2170 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2171 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2173 unsigned char op1 = view[-1];
2174 unsigned char op2 = view[-2];
2176 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2177 op2 == 0x8d || op2 == 0x04);
2178 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2182 // FIXME: For now, support only the first (SIB) form.
2183 tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2187 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2188 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2189 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2190 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2191 memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2195 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2196 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2197 if (rel.get_r_offset() + 9 < view_size
2200 // FIXME: This is not the right instruction sequence.
2201 // There is a trailing nop. Use the size byte subl.
2202 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2207 // FIXME: This is not the right instruction sequence.
2208 // Use the five byte subl.
2209 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2213 Relocate_functions<32, false>::rel32(view + roff, value);
2215 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2217 this->skip_call_tls_get_addr_ = true;
2220 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2221 // General-Dynamic to a Local-Exec.
2224 Target_i386::Relocate::tls_desc_gd_to_le(
2225 const Relocate_info<32, false>* relinfo,
2227 Output_segment* tls_segment,
2228 const elfcpp::Rel<32, false>& rel,
2229 unsigned int r_type,
2230 elfcpp::Elf_types<32>::Elf_Addr value,
2231 unsigned char* view,
2232 section_size_type view_size)
2234 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2236 // leal foo@TLSDESC(%ebx), %eax
2237 // ==> leal foo@NTPOFF, %eax
2238 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2239 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2240 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2241 view[-2] == 0x8d && view[-1] == 0x83);
2243 value -= tls_segment->memsz();
2244 Relocate_functions<32, false>::rel32(view, value);
2248 // call *foo@TLSCALL(%eax)
2250 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2251 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2252 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2253 view[0] == 0xff && view[1] == 0x10);
2259 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2260 // General-Dynamic to an Initial-Exec.
2263 Target_i386::Relocate::tls_desc_gd_to_ie(
2264 const Relocate_info<32, false>* relinfo,
2267 const elfcpp::Rel<32, false>& rel,
2268 unsigned int r_type,
2269 elfcpp::Elf_types<32>::Elf_Addr value,
2270 unsigned char* view,
2271 section_size_type view_size)
2273 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2275 // leal foo@TLSDESC(%ebx), %eax
2276 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2277 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2278 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2279 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2280 view[-2] == 0x8d && view[-1] == 0x83);
2282 Relocate_functions<32, false>::rel32(view, value);
2286 // call *foo@TLSCALL(%eax)
2288 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2289 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2290 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2291 view[0] == 0xff && view[1] == 0x10);
2297 // Do a relocation in which we convert a TLS Local-Dynamic to a
2301 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2304 const elfcpp::Rel<32, false>& rel,
2306 elfcpp::Elf_types<32>::Elf_Addr,
2307 unsigned char* view,
2308 section_size_type view_size)
2310 // leal foo(%reg), %eax; call ___tls_get_addr
2311 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2313 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2314 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2316 // FIXME: Does this test really always pass?
2317 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2318 view[-2] == 0x8d && view[-1] == 0x83);
2320 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2322 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2324 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2326 this->skip_call_tls_get_addr_ = true;
2329 // Do a relocation in which we convert a TLS Initial-Exec to a
2333 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2335 Output_segment* tls_segment,
2336 const elfcpp::Rel<32, false>& rel,
2337 unsigned int r_type,
2338 elfcpp::Elf_types<32>::Elf_Addr value,
2339 unsigned char* view,
2340 section_size_type view_size)
2342 // We have to actually change the instructions, which means that we
2343 // need to examine the opcodes to figure out which instruction we
2345 if (r_type == elfcpp::R_386_TLS_IE)
2347 // movl %gs:XX,%eax ==> movl $YY,%eax
2348 // movl %gs:XX,%reg ==> movl $YY,%reg
2349 // addl %gs:XX,%reg ==> addl $YY,%reg
2350 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2351 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2353 unsigned char op1 = view[-1];
2356 // movl XX,%eax ==> movl $YY,%eax
2361 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2363 unsigned char op2 = view[-2];
2366 // movl XX,%reg ==> movl $YY,%reg
2367 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2368 (op1 & 0xc7) == 0x05);
2370 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2372 else if (op2 == 0x03)
2374 // addl XX,%reg ==> addl $YY,%reg
2375 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2376 (op1 & 0xc7) == 0x05);
2378 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2381 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2386 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2387 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2388 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2389 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2390 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2392 unsigned char op1 = view[-1];
2393 unsigned char op2 = view[-2];
2394 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2395 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2398 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2400 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2402 else if (op2 == 0x2b)
2404 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2406 view[-1] = 0xe8 | ((op1 >> 3) & 7);
2408 else if (op2 == 0x03)
2410 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2412 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2415 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2418 value = tls_segment->memsz() - value;
2419 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2422 Relocate_functions<32, false>::rel32(view, value);
2425 // Relocate section data.
2428 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2429 unsigned int sh_type,
2430 const unsigned char* prelocs,
2432 Output_section* output_section,
2433 bool needs_special_offset_handling,
2434 unsigned char* view,
2435 elfcpp::Elf_types<32>::Elf_Addr address,
2436 section_size_type view_size,
2437 const Reloc_symbol_changes* reloc_symbol_changes)
2439 gold_assert(sh_type == elfcpp::SHT_REL);
2441 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2442 Target_i386::Relocate>(
2448 needs_special_offset_handling,
2452 reloc_symbol_changes);
2455 // Return the size of a relocation while scanning during a relocatable
2459 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2460 unsigned int r_type,
2465 case elfcpp::R_386_NONE:
2466 case elfcpp::R_386_GNU_VTINHERIT:
2467 case elfcpp::R_386_GNU_VTENTRY:
2468 case elfcpp::R_386_TLS_GD: // Global-dynamic
2469 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2470 case elfcpp::R_386_TLS_DESC_CALL:
2471 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2472 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2473 case elfcpp::R_386_TLS_IE: // Initial-exec
2474 case elfcpp::R_386_TLS_IE_32:
2475 case elfcpp::R_386_TLS_GOTIE:
2476 case elfcpp::R_386_TLS_LE: // Local-exec
2477 case elfcpp::R_386_TLS_LE_32:
2480 case elfcpp::R_386_32:
2481 case elfcpp::R_386_PC32:
2482 case elfcpp::R_386_GOT32:
2483 case elfcpp::R_386_PLT32:
2484 case elfcpp::R_386_GOTOFF:
2485 case elfcpp::R_386_GOTPC:
2488 case elfcpp::R_386_16:
2489 case elfcpp::R_386_PC16:
2492 case elfcpp::R_386_8:
2493 case elfcpp::R_386_PC8:
2496 // These are relocations which should only be seen by the
2497 // dynamic linker, and should never be seen here.
2498 case elfcpp::R_386_COPY:
2499 case elfcpp::R_386_GLOB_DAT:
2500 case elfcpp::R_386_JUMP_SLOT:
2501 case elfcpp::R_386_RELATIVE:
2502 case elfcpp::R_386_TLS_TPOFF:
2503 case elfcpp::R_386_TLS_DTPMOD32:
2504 case elfcpp::R_386_TLS_DTPOFF32:
2505 case elfcpp::R_386_TLS_TPOFF32:
2506 case elfcpp::R_386_TLS_DESC:
2507 object->error(_("unexpected reloc %u in object file"), r_type);
2510 case elfcpp::R_386_32PLT:
2511 case elfcpp::R_386_TLS_GD_32:
2512 case elfcpp::R_386_TLS_GD_PUSH:
2513 case elfcpp::R_386_TLS_GD_CALL:
2514 case elfcpp::R_386_TLS_GD_POP:
2515 case elfcpp::R_386_TLS_LDM_32:
2516 case elfcpp::R_386_TLS_LDM_PUSH:
2517 case elfcpp::R_386_TLS_LDM_CALL:
2518 case elfcpp::R_386_TLS_LDM_POP:
2519 case elfcpp::R_386_USED_BY_INTEL_200:
2521 object->error(_("unsupported reloc %u in object file"), r_type);
2526 // Scan the relocs during a relocatable link.
2529 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
2531 Sized_relobj<32, false>* object,
2532 unsigned int data_shndx,
2533 unsigned int sh_type,
2534 const unsigned char* prelocs,
2536 Output_section* output_section,
2537 bool needs_special_offset_handling,
2538 size_t local_symbol_count,
2539 const unsigned char* plocal_symbols,
2540 Relocatable_relocs* rr)
2542 gold_assert(sh_type == elfcpp::SHT_REL);
2544 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2545 Relocatable_size_for_reloc> Scan_relocatable_relocs;
2547 gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2548 Scan_relocatable_relocs>(
2556 needs_special_offset_handling,
2562 // Relocate a section during a relocatable link.
2565 Target_i386::relocate_for_relocatable(
2566 const Relocate_info<32, false>* relinfo,
2567 unsigned int sh_type,
2568 const unsigned char* prelocs,
2570 Output_section* output_section,
2571 off_t offset_in_output_section,
2572 const Relocatable_relocs* rr,
2573 unsigned char* view,
2574 elfcpp::Elf_types<32>::Elf_Addr view_address,
2575 section_size_type view_size,
2576 unsigned char* reloc_view,
2577 section_size_type reloc_view_size)
2579 gold_assert(sh_type == elfcpp::SHT_REL);
2581 gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2586 offset_in_output_section,
2595 // Return the value to use for a dynamic which requires special
2596 // treatment. This is how we support equality comparisons of function
2597 // pointers across shared library boundaries, as described in the
2598 // processor specific ABI supplement.
2601 Target_i386::do_dynsym_value(const Symbol* gsym) const
2603 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2604 return this->plt_section()->address() + gsym->plt_offset();
2607 // Return a string used to fill a code section with nops to take up
2608 // the specified length.
2611 Target_i386::do_code_fill(section_size_type length) const
2615 // Build a jmp instruction to skip over the bytes.
2616 unsigned char jmp[5];
2618 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2619 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2620 + std::string(length - 5, '\0'));
2623 // Nop sequences of various lengths.
2624 const char nop1[1] = { 0x90 }; // nop
2625 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
2626 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2627 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2628 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2629 0x00 }; // leal 0(%esi,1),%esi
2630 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2632 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2634 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2635 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2636 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2637 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2639 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2640 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2642 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2643 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2645 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2646 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2647 0x00, 0x00, 0x00, 0x00 };
2648 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2649 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2650 0x27, 0x00, 0x00, 0x00,
2652 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2653 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2654 0xbc, 0x27, 0x00, 0x00,
2656 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2657 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2658 0x90, 0x90, 0x90, 0x90,
2661 const char* nops[16] = {
2663 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2664 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2667 return std::string(nops[length], length);
2670 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2671 // compiled with -fstack-split. The function calls non-stack-split
2672 // code. We have to change the function so that it always ensures
2673 // that it has enough stack space to run some random function.
2676 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
2677 section_offset_type fnoffset,
2678 section_size_type fnsize,
2679 unsigned char* view,
2680 section_size_type view_size,
2682 std::string* to) const
2684 // The function starts with a comparison of the stack pointer and a
2685 // field in the TCB. This is followed by a jump.
2688 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
2691 // We will call __morestack if the carry flag is set after this
2692 // comparison. We turn the comparison into an stc instruction
2694 view[fnoffset] = '\xf9';
2695 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
2697 // lea NN(%esp),%ecx
2698 else if (this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
2701 // This is loading an offset from the stack pointer for a
2702 // comparison. The offset is negative, so we decrease the
2703 // offset by the amount of space we need for the stack. This
2704 // means we will avoid calling __morestack if there happens to
2705 // be plenty of space on the stack already.
2706 unsigned char* pval = view + fnoffset + 3;
2707 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2708 val -= parameters->options().split_stack_adjust_size();
2709 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2713 if (!object->has_no_split_stack())
2714 object->error(_("failed to match split-stack sequence at "
2715 "section %u offset %0zx"),
2720 // We have to change the function so that it calls
2721 // __morestack_non_split instead of __morestack. The former will
2722 // allocate additional stack space.
2723 *from = "__morestack";
2724 *to = "__morestack_non_split";
2727 // The selector for i386 object files.
2729 class Target_selector_i386 : public Target_selector_freebsd
2732 Target_selector_i386()
2733 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2734 "elf32-i386", "elf32-i386-freebsd")
2738 do_instantiate_target()
2739 { return new Target_i386(); }
2742 Target_selector_i386 target_selector_i386;
2744 } // End anonymous namespace.