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), global_offset_table_(NULL),
63 rel_dyn_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
64 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
68 can_check_for_function_pointers() const
71 // Process the relocations to determine unreferenced sections for
72 // garbage collection.
74 gc_process_relocs(Symbol_table* symtab,
76 Sized_relobj<32, false>* object,
77 unsigned int data_shndx,
79 const unsigned char* prelocs,
81 Output_section* output_section,
82 bool needs_special_offset_handling,
83 size_t local_symbol_count,
84 const unsigned char* plocal_symbols);
86 // Scan the relocations to look for symbol adjustments.
88 scan_relocs(Symbol_table* symtab,
90 Sized_relobj<32, false>* object,
91 unsigned int data_shndx,
93 const unsigned char* prelocs,
95 Output_section* output_section,
96 bool needs_special_offset_handling,
97 size_t local_symbol_count,
98 const unsigned char* plocal_symbols);
100 // Finalize the sections.
102 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
104 // Return the value to use for a dynamic which requires special
107 do_dynsym_value(const Symbol*) const;
109 // Relocate a section.
111 relocate_section(const Relocate_info<32, false>*,
112 unsigned int sh_type,
113 const unsigned char* prelocs,
115 Output_section* output_section,
116 bool needs_special_offset_handling,
118 elfcpp::Elf_types<32>::Elf_Addr view_address,
119 section_size_type view_size,
120 const Reloc_symbol_changes*);
122 // Scan the relocs during a relocatable link.
124 scan_relocatable_relocs(Symbol_table* symtab,
126 Sized_relobj<32, false>* object,
127 unsigned int data_shndx,
128 unsigned int sh_type,
129 const unsigned char* prelocs,
131 Output_section* output_section,
132 bool needs_special_offset_handling,
133 size_t local_symbol_count,
134 const unsigned char* plocal_symbols,
135 Relocatable_relocs*);
137 // Relocate a section during a relocatable link.
139 relocate_for_relocatable(const Relocate_info<32, false>*,
140 unsigned int sh_type,
141 const unsigned char* prelocs,
143 Output_section* output_section,
144 off_t offset_in_output_section,
145 const Relocatable_relocs*,
147 elfcpp::Elf_types<32>::Elf_Addr view_address,
148 section_size_type view_size,
149 unsigned char* reloc_view,
150 section_size_type reloc_view_size);
152 // Return a string used to fill a code section with nops.
154 do_code_fill(section_size_type length) const;
156 // Return whether SYM is defined by the ABI.
158 do_is_defined_by_abi(const Symbol* sym) const
159 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
161 // Return whether a symbol name implies a local label. The UnixWare
162 // 2.1 cc generates temporary symbols that start with .X, so we
163 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
164 // If so, we should move the .X recognition into
165 // Target::do_is_local_label_name.
167 do_is_local_label_name(const char* name) const
169 if (name[0] == '.' && name[1] == 'X')
171 return Target::do_is_local_label_name(name);
174 // Return whether SYM is call to a non-split function.
176 do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
178 // Adjust -fstack-split code which calls non-stack-split code.
180 do_calls_non_split(Relobj* object, unsigned int shndx,
181 section_offset_type fnoffset, section_size_type fnsize,
182 unsigned char* view, section_size_type view_size,
183 std::string* from, std::string* to) const;
185 // Return the size of the GOT section.
189 gold_assert(this->got_ != NULL);
190 return this->got_->data_size();
194 // The class which scans relocations.
198 local(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,
203 const elfcpp::Sym<32, false>& lsym);
206 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
207 Sized_relobj<32, false>* object,
208 unsigned int data_shndx,
209 Output_section* output_section,
210 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
214 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
216 Sized_relobj<32, false>* object,
217 unsigned int data_shndx,
218 Output_section* output_section,
219 const elfcpp::Rel<32, false>& reloc,
221 const elfcpp::Sym<32, false>& lsym);
224 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
226 Sized_relobj<32, false>* object,
227 unsigned int data_shndx,
228 Output_section* output_section,
229 const elfcpp::Rel<32, false>& reloc,
234 possible_function_pointer_reloc(unsigned int r_type);
237 unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
240 unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
244 // The class which implements relocation.
249 : skip_call_tls_get_addr_(false),
250 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
255 if (this->skip_call_tls_get_addr_)
257 // FIXME: This needs to specify the location somehow.
258 gold_error(_("missing expected TLS relocation"));
262 // Return whether the static relocation needs to be applied.
264 should_apply_static_reloc(const Sized_symbol<32>* gsym,
267 Output_section* output_section);
269 // Do a relocation. Return false if the caller should not issue
270 // any warnings about this relocation.
272 relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
273 size_t relnum, const elfcpp::Rel<32, false>&,
274 unsigned int r_type, const Sized_symbol<32>*,
275 const Symbol_value<32>*,
276 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
280 // Do a TLS relocation.
282 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
283 size_t relnum, const elfcpp::Rel<32, false>&,
284 unsigned int r_type, const Sized_symbol<32>*,
285 const Symbol_value<32>*,
286 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
289 // Do a TLS General-Dynamic to Initial-Exec transition.
291 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
292 Output_segment* tls_segment,
293 const elfcpp::Rel<32, false>&, unsigned int r_type,
294 elfcpp::Elf_types<32>::Elf_Addr value,
296 section_size_type view_size);
298 // Do a TLS General-Dynamic to Local-Exec transition.
300 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
301 Output_segment* tls_segment,
302 const elfcpp::Rel<32, false>&, unsigned int r_type,
303 elfcpp::Elf_types<32>::Elf_Addr value,
305 section_size_type view_size);
307 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
310 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
311 Output_segment* tls_segment,
312 const elfcpp::Rel<32, false>&, unsigned int r_type,
313 elfcpp::Elf_types<32>::Elf_Addr value,
315 section_size_type view_size);
317 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
320 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
321 Output_segment* tls_segment,
322 const elfcpp::Rel<32, false>&, unsigned int r_type,
323 elfcpp::Elf_types<32>::Elf_Addr value,
325 section_size_type view_size);
327 // Do a TLS Local-Dynamic to Local-Exec transition.
329 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
330 Output_segment* tls_segment,
331 const elfcpp::Rel<32, false>&, unsigned int r_type,
332 elfcpp::Elf_types<32>::Elf_Addr value,
334 section_size_type view_size);
336 // Do a TLS Initial-Exec to Local-Exec transition.
338 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
339 Output_segment* tls_segment,
340 const elfcpp::Rel<32, false>&, unsigned int r_type,
341 elfcpp::Elf_types<32>::Elf_Addr value,
343 section_size_type view_size);
345 // We need to keep track of which type of local dynamic relocation
346 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
347 enum Local_dynamic_type
354 // This is set if we should skip the next reloc, which should be a
355 // PLT32 reloc against ___tls_get_addr.
356 bool skip_call_tls_get_addr_;
357 // The type of local dynamic relocation we have seen in the section
358 // being relocated, if any.
359 Local_dynamic_type local_dynamic_type_;
362 // A class which returns the size required for a relocation type,
363 // used while scanning relocs during a relocatable link.
364 class Relocatable_size_for_reloc
368 get_size_for_reloc(unsigned int, Relobj*);
371 // Adjust TLS relocation type based on the options and whether this
372 // is a local symbol.
373 static tls::Tls_optimization
374 optimize_tls_reloc(bool is_final, int r_type);
376 // Get the GOT section, creating it if necessary.
377 Output_data_got<32, false>*
378 got_section(Symbol_table*, Layout*);
380 // Get the GOT PLT section.
382 got_plt_section() const
384 gold_assert(this->got_plt_ != NULL);
385 return this->got_plt_;
388 // Create a PLT entry for a global symbol.
390 make_plt_entry(Symbol_table*, Layout*, Symbol*);
392 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
394 define_tls_base_symbol(Symbol_table*, Layout*);
396 // Create a GOT entry for the TLS module index.
398 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
399 Sized_relobj<32, false>* object);
401 // Get the PLT section.
402 Output_data_plt_i386*
405 gold_assert(this->plt_ != NULL);
409 // Get the dynamic reloc section, creating it if necessary.
411 rel_dyn_section(Layout*);
413 // Get the section to use for TLS_DESC relocations.
415 rel_tls_desc_section(Layout*) const;
417 // Add a potential copy relocation.
419 copy_reloc(Symbol_table* symtab, Layout* layout,
420 Sized_relobj<32, false>* object,
421 unsigned int shndx, Output_section* output_section,
422 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
424 this->copy_relocs_.copy_reloc(symtab, layout,
425 symtab->get_sized_symbol<32>(sym),
426 object, shndx, output_section, reloc,
427 this->rel_dyn_section(layout));
430 // Information about this specific target which we pass to the
431 // general Target structure.
432 static const Target::Target_info i386_info;
434 // The types of GOT entries needed for this platform.
437 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
438 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
439 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
440 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
441 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
445 Output_data_got<32, false>* got_;
447 Output_data_plt_i386* plt_;
448 // The GOT PLT section.
449 Output_data_space* got_plt_;
450 // The _GLOBAL_OFFSET_TABLE_ symbol.
451 Symbol* global_offset_table_;
452 // The dynamic reloc section.
453 Reloc_section* rel_dyn_;
454 // Relocs saved to avoid a COPY reloc.
455 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
456 // Space for variables copied with a COPY reloc.
457 Output_data_space* dynbss_;
458 // Offset of the GOT entry for the TLS module index.
459 unsigned int got_mod_index_offset_;
460 // True if the _TLS_MODULE_BASE_ symbol has been defined.
461 bool tls_base_symbol_defined_;
464 const Target::Target_info Target_i386::i386_info =
467 false, // is_big_endian
468 elfcpp::EM_386, // machine_code
469 false, // has_make_symbol
470 false, // has_resolve
471 true, // has_code_fill
472 true, // is_default_stack_executable
474 "/usr/lib/libc.so.1", // dynamic_linker
475 0x08048000, // default_text_segment_address
476 0x1000, // abi_pagesize (overridable by -z max-page-size)
477 0x1000, // common_pagesize (overridable by -z common-page-size)
478 elfcpp::SHN_UNDEF, // small_common_shndx
479 elfcpp::SHN_UNDEF, // large_common_shndx
480 0, // small_common_section_flags
481 0, // large_common_section_flags
482 NULL, // attributes_section
483 NULL // attributes_vendor
486 // Get the GOT section, creating it if necessary.
488 Output_data_got<32, false>*
489 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
491 if (this->got_ == NULL)
493 gold_assert(symtab != NULL && layout != NULL);
495 this->got_ = new Output_data_got<32, false>();
497 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
499 | elfcpp::SHF_WRITE),
500 this->got_, false, true, true, false);
502 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
503 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
505 | elfcpp::SHF_WRITE),
506 this->got_plt_, false, false, false,
509 // The first three entries are reserved.
510 this->got_plt_->set_current_data_size(3 * 4);
512 // Those bytes can go into the relro segment.
513 layout->increase_relro(3 * 4);
515 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
516 this->global_offset_table_ =
517 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
518 Symbol_table::PREDEFINED,
520 0, 0, elfcpp::STT_OBJECT,
522 elfcpp::STV_HIDDEN, 0,
529 // Get the dynamic reloc section, creating it if necessary.
531 Target_i386::Reloc_section*
532 Target_i386::rel_dyn_section(Layout* layout)
534 if (this->rel_dyn_ == NULL)
536 gold_assert(layout != NULL);
537 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
538 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
539 elfcpp::SHF_ALLOC, this->rel_dyn_, true,
540 false, false, false);
542 return this->rel_dyn_;
545 // A class to handle the PLT data.
547 class Output_data_plt_i386 : public Output_section_data
550 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
552 Output_data_plt_i386(Layout*, Output_data_space*);
554 // Add an entry to the PLT.
556 add_entry(Symbol* gsym);
558 // Return the .rel.plt section data.
561 { return this->rel_; }
563 // Return where the TLS_DESC relocations should go.
565 rel_tls_desc(Layout*);
569 do_adjust_output_section(Output_section* os);
571 // Write to a map file.
573 do_print_to_mapfile(Mapfile* mapfile) const
574 { mapfile->print_output_data(this, _("** PLT")); }
577 // The size of an entry in the PLT.
578 static const int plt_entry_size = 16;
580 // The first entry in the PLT for an executable.
581 static unsigned char exec_first_plt_entry[plt_entry_size];
583 // The first entry in the PLT for a shared object.
584 static unsigned char dyn_first_plt_entry[plt_entry_size];
586 // Other entries in the PLT for an executable.
587 static unsigned char exec_plt_entry[plt_entry_size];
589 // Other entries in the PLT for a shared object.
590 static unsigned char dyn_plt_entry[plt_entry_size];
592 // Set the final size.
594 set_final_data_size()
595 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
597 // Write out the PLT data.
599 do_write(Output_file*);
601 // The reloc section.
603 // The TLS_DESC relocations, if necessary. These must follow the
604 // regular PLT relocs.
605 Reloc_section* tls_desc_rel_;
606 // The .got.plt section.
607 Output_data_space* got_plt_;
608 // The number of PLT entries.
612 // Create the PLT section. The ordinary .got section is an argument,
613 // since we need to refer to the start. We also create our own .got
614 // section just for PLT entries.
616 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
617 Output_data_space* got_plt)
618 : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0)
620 this->rel_ = new Reloc_section(false);
621 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
622 elfcpp::SHF_ALLOC, this->rel_, true,
623 false, false, false);
627 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
629 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
630 // linker, and so do we.
634 // Add an entry to the PLT.
637 Output_data_plt_i386::add_entry(Symbol* gsym)
639 gold_assert(!gsym->has_plt_offset());
641 // Note that when setting the PLT offset we skip the initial
642 // reserved PLT entry.
643 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
647 section_offset_type got_offset = this->got_plt_->current_data_size();
649 // Every PLT entry needs a GOT entry which points back to the PLT
650 // entry (this will be changed by the dynamic linker, normally
651 // lazily when the function is called).
652 this->got_plt_->set_current_data_size(got_offset + 4);
654 // Every PLT entry needs a reloc.
655 gsym->set_needs_dynsym_entry();
656 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
659 // Note that we don't need to save the symbol. The contents of the
660 // PLT are independent of which symbols are used. The symbols only
661 // appear in the relocations.
664 // Return where the TLS_DESC relocations should go, creating it if
665 // necessary. These follow the JUMP_SLOT relocations.
667 Output_data_plt_i386::Reloc_section*
668 Output_data_plt_i386::rel_tls_desc(Layout* layout)
670 if (this->tls_desc_rel_ == NULL)
672 this->tls_desc_rel_ = new Reloc_section(false);
673 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
674 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
675 true, false, false, false);
676 gold_assert(this->tls_desc_rel_->output_section() ==
677 this->rel_->output_section());
679 return this->tls_desc_rel_;
682 // The first entry in the PLT for an executable.
684 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
686 0xff, 0x35, // pushl contents of memory address
687 0, 0, 0, 0, // replaced with address of .got + 4
688 0xff, 0x25, // jmp indirect
689 0, 0, 0, 0, // replaced with address of .got + 8
693 // The first entry in the PLT for a shared object.
695 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
697 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
698 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
702 // Subsequent entries in the PLT for an executable.
704 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
706 0xff, 0x25, // jmp indirect
707 0, 0, 0, 0, // replaced with address of symbol in .got
708 0x68, // pushl immediate
709 0, 0, 0, 0, // replaced with offset into relocation table
710 0xe9, // jmp relative
711 0, 0, 0, 0 // replaced with offset to start of .plt
714 // Subsequent entries in the PLT for a shared object.
716 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
718 0xff, 0xa3, // jmp *offset(%ebx)
719 0, 0, 0, 0, // replaced with offset of symbol in .got
720 0x68, // pushl immediate
721 0, 0, 0, 0, // replaced with offset into relocation table
722 0xe9, // jmp relative
723 0, 0, 0, 0 // replaced with offset to start of .plt
726 // Write out the PLT. This uses the hand-coded instructions above,
727 // and adjusts them as needed. This is all specified by the i386 ELF
728 // Processor Supplement.
731 Output_data_plt_i386::do_write(Output_file* of)
733 const off_t offset = this->offset();
734 const section_size_type oview_size =
735 convert_to_section_size_type(this->data_size());
736 unsigned char* const oview = of->get_output_view(offset, oview_size);
738 const off_t got_file_offset = this->got_plt_->offset();
739 const section_size_type got_size =
740 convert_to_section_size_type(this->got_plt_->data_size());
741 unsigned char* const got_view = of->get_output_view(got_file_offset,
744 unsigned char* pov = oview;
746 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
747 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
749 if (parameters->options().output_is_position_independent())
750 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
753 memcpy(pov, exec_first_plt_entry, plt_entry_size);
754 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
755 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
757 pov += plt_entry_size;
759 unsigned char* got_pov = got_view;
761 memset(got_pov, 0, 12);
764 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
766 unsigned int plt_offset = plt_entry_size;
767 unsigned int plt_rel_offset = 0;
768 unsigned int got_offset = 12;
769 const unsigned int count = this->count_;
770 for (unsigned int i = 0;
773 pov += plt_entry_size,
775 plt_offset += plt_entry_size,
776 plt_rel_offset += rel_size,
779 // Set and adjust the PLT entry itself.
781 if (parameters->options().output_is_position_independent())
783 memcpy(pov, dyn_plt_entry, plt_entry_size);
784 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
788 memcpy(pov, exec_plt_entry, plt_entry_size);
789 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
794 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
795 elfcpp::Swap<32, false>::writeval(pov + 12,
796 - (plt_offset + plt_entry_size));
798 // Set the entry in the GOT.
799 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
802 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
803 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
805 of->write_output_view(offset, oview_size, oview);
806 of->write_output_view(got_file_offset, got_size, got_view);
809 // Create a PLT entry for a global symbol.
812 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
814 if (gsym->has_plt_offset())
817 if (this->plt_ == NULL)
819 // Create the GOT sections first.
820 this->got_section(symtab, layout);
822 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
823 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
825 | elfcpp::SHF_EXECINSTR),
826 this->plt_, false, false, false, false);
829 this->plt_->add_entry(gsym);
832 // Get the section to use for TLS_DESC relocations.
834 Target_i386::Reloc_section*
835 Target_i386::rel_tls_desc_section(Layout* layout) const
837 return this->plt_section()->rel_tls_desc(layout);
840 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
843 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
845 if (this->tls_base_symbol_defined_)
848 Output_segment* tls_segment = layout->tls_segment();
849 if (tls_segment != NULL)
851 bool is_exec = parameters->options().output_is_executable();
852 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
853 Symbol_table::PREDEFINED,
857 elfcpp::STV_HIDDEN, 0,
859 ? Symbol::SEGMENT_END
860 : Symbol::SEGMENT_START),
863 this->tls_base_symbol_defined_ = true;
866 // Create a GOT entry for the TLS module index.
869 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
870 Sized_relobj<32, false>* object)
872 if (this->got_mod_index_offset_ == -1U)
874 gold_assert(symtab != NULL && layout != NULL && object != NULL);
875 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
876 Output_data_got<32, false>* got = this->got_section(symtab, layout);
877 unsigned int got_offset = got->add_constant(0);
878 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
880 got->add_constant(0);
881 this->got_mod_index_offset_ = got_offset;
883 return this->got_mod_index_offset_;
886 // Optimize the TLS relocation type based on what we know about the
887 // symbol. IS_FINAL is true if the final address of this symbol is
888 // known at link time.
890 tls::Tls_optimization
891 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
893 // If we are generating a shared library, then we can't do anything
895 if (parameters->options().shared())
896 return tls::TLSOPT_NONE;
900 case elfcpp::R_386_TLS_GD:
901 case elfcpp::R_386_TLS_GOTDESC:
902 case elfcpp::R_386_TLS_DESC_CALL:
903 // These are General-Dynamic which permits fully general TLS
904 // access. Since we know that we are generating an executable,
905 // we can convert this to Initial-Exec. If we also know that
906 // this is a local symbol, we can further switch to Local-Exec.
908 return tls::TLSOPT_TO_LE;
909 return tls::TLSOPT_TO_IE;
911 case elfcpp::R_386_TLS_LDM:
912 // This is Local-Dynamic, which refers to a local symbol in the
913 // dynamic TLS block. Since we know that we generating an
914 // executable, we can switch to Local-Exec.
915 return tls::TLSOPT_TO_LE;
917 case elfcpp::R_386_TLS_LDO_32:
918 // Another type of Local-Dynamic relocation.
919 return tls::TLSOPT_TO_LE;
921 case elfcpp::R_386_TLS_IE:
922 case elfcpp::R_386_TLS_GOTIE:
923 case elfcpp::R_386_TLS_IE_32:
924 // These are Initial-Exec relocs which get the thread offset
925 // from the GOT. If we know that we are linking against the
926 // local symbol, we can switch to Local-Exec, which links the
927 // thread offset into the instruction.
929 return tls::TLSOPT_TO_LE;
930 return tls::TLSOPT_NONE;
932 case elfcpp::R_386_TLS_LE:
933 case elfcpp::R_386_TLS_LE_32:
934 // When we already have Local-Exec, there is nothing further we
936 return tls::TLSOPT_NONE;
943 // Report an unsupported relocation against a local symbol.
946 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
949 gold_error(_("%s: unsupported reloc %u against local symbol"),
950 object->name().c_str(), r_type);
953 // Scan a relocation for a local symbol.
956 Target_i386::Scan::local(Symbol_table* symtab,
959 Sized_relobj<32, false>* object,
960 unsigned int data_shndx,
961 Output_section* output_section,
962 const elfcpp::Rel<32, false>& reloc,
964 const elfcpp::Sym<32, false>& lsym)
968 case elfcpp::R_386_NONE:
969 case elfcpp::R_386_GNU_VTINHERIT:
970 case elfcpp::R_386_GNU_VTENTRY:
973 case elfcpp::R_386_32:
974 // If building a shared library (or a position-independent
975 // executable), we need to create a dynamic relocation for
976 // this location. The relocation applied at link time will
977 // apply the link-time value, so we flag the location with
978 // an R_386_RELATIVE relocation so the dynamic loader can
979 // relocate it easily.
980 if (parameters->options().output_is_position_independent())
982 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
983 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
984 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
985 output_section, data_shndx,
986 reloc.get_r_offset());
990 case elfcpp::R_386_16:
991 case elfcpp::R_386_8:
992 // If building a shared library (or a position-independent
993 // executable), we need to create a dynamic relocation for
994 // this location. Because the addend needs to remain in the
995 // data section, we need to be careful not to apply this
996 // relocation statically.
997 if (parameters->options().output_is_position_independent())
999 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1000 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1001 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1002 rel_dyn->add_local(object, r_sym, r_type, output_section,
1003 data_shndx, reloc.get_r_offset());
1006 gold_assert(lsym.get_st_value() == 0);
1007 unsigned int shndx = lsym.get_st_shndx();
1009 shndx = object->adjust_sym_shndx(r_sym, shndx,
1012 object->error(_("section symbol %u has bad shndx %u"),
1015 rel_dyn->add_local_section(object, shndx,
1016 r_type, output_section,
1017 data_shndx, reloc.get_r_offset());
1022 case elfcpp::R_386_PC32:
1023 case elfcpp::R_386_PC16:
1024 case elfcpp::R_386_PC8:
1027 case elfcpp::R_386_PLT32:
1028 // Since we know this is a local symbol, we can handle this as a
1032 case elfcpp::R_386_GOTOFF:
1033 case elfcpp::R_386_GOTPC:
1034 // We need a GOT section.
1035 target->got_section(symtab, layout);
1038 case elfcpp::R_386_GOT32:
1040 // The symbol requires a GOT entry.
1041 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1042 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1043 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1045 // If we are generating a shared object, we need to add a
1046 // dynamic RELATIVE relocation for this symbol's GOT entry.
1047 if (parameters->options().output_is_position_independent())
1049 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1050 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1051 rel_dyn->add_local_relative(
1052 object, r_sym, elfcpp::R_386_RELATIVE, got,
1053 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
1059 // These are relocations which should only be seen by the
1060 // dynamic linker, and should never be seen here.
1061 case elfcpp::R_386_COPY:
1062 case elfcpp::R_386_GLOB_DAT:
1063 case elfcpp::R_386_JUMP_SLOT:
1064 case elfcpp::R_386_RELATIVE:
1065 case elfcpp::R_386_TLS_TPOFF:
1066 case elfcpp::R_386_TLS_DTPMOD32:
1067 case elfcpp::R_386_TLS_DTPOFF32:
1068 case elfcpp::R_386_TLS_TPOFF32:
1069 case elfcpp::R_386_TLS_DESC:
1070 gold_error(_("%s: unexpected reloc %u in object file"),
1071 object->name().c_str(), r_type);
1074 // These are initial TLS relocs, which are expected when
1076 case elfcpp::R_386_TLS_GD: // Global-dynamic
1077 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1078 case elfcpp::R_386_TLS_DESC_CALL:
1079 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1080 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1081 case elfcpp::R_386_TLS_IE: // Initial-exec
1082 case elfcpp::R_386_TLS_IE_32:
1083 case elfcpp::R_386_TLS_GOTIE:
1084 case elfcpp::R_386_TLS_LE: // Local-exec
1085 case elfcpp::R_386_TLS_LE_32:
1087 bool output_is_shared = parameters->options().shared();
1088 const tls::Tls_optimization optimized_type
1089 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1092 case elfcpp::R_386_TLS_GD: // Global-dynamic
1093 if (optimized_type == tls::TLSOPT_NONE)
1095 // Create a pair of GOT entries for the module index and
1096 // dtv-relative offset.
1097 Output_data_got<32, false>* got
1098 = target->got_section(symtab, layout);
1099 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1100 unsigned int shndx = lsym.get_st_shndx();
1102 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1104 object->error(_("local symbol %u has bad shndx %u"),
1107 got->add_local_pair_with_rel(object, r_sym, shndx,
1109 target->rel_dyn_section(layout),
1110 elfcpp::R_386_TLS_DTPMOD32, 0);
1112 else if (optimized_type != tls::TLSOPT_TO_LE)
1113 unsupported_reloc_local(object, r_type);
1116 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1117 target->define_tls_base_symbol(symtab, layout);
1118 if (optimized_type == tls::TLSOPT_NONE)
1120 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1121 Output_data_got<32, false>* got
1122 = target->got_section(symtab, layout);
1123 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1124 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1126 unsigned int got_offset = got->add_constant(0);
1127 // The local symbol value is stored in the second
1129 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1130 // That set the GOT offset of the local symbol to
1131 // point to the second entry, but we want it to
1132 // point to the first.
1133 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1135 Reloc_section* rt = target->rel_tls_desc_section(layout);
1136 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1139 else if (optimized_type != tls::TLSOPT_TO_LE)
1140 unsupported_reloc_local(object, r_type);
1143 case elfcpp::R_386_TLS_DESC_CALL:
1146 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1147 if (optimized_type == tls::TLSOPT_NONE)
1149 // Create a GOT entry for the module index.
1150 target->got_mod_index_entry(symtab, layout, object);
1152 else if (optimized_type != tls::TLSOPT_TO_LE)
1153 unsupported_reloc_local(object, r_type);
1156 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1159 case elfcpp::R_386_TLS_IE: // Initial-exec
1160 case elfcpp::R_386_TLS_IE_32:
1161 case elfcpp::R_386_TLS_GOTIE:
1162 layout->set_has_static_tls();
1163 if (optimized_type == tls::TLSOPT_NONE)
1165 // For the R_386_TLS_IE relocation, we need to create a
1166 // dynamic relocation when building a shared library.
1167 if (r_type == elfcpp::R_386_TLS_IE
1168 && parameters->options().shared())
1170 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1172 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1173 rel_dyn->add_local_relative(object, r_sym,
1174 elfcpp::R_386_RELATIVE,
1175 output_section, data_shndx,
1176 reloc.get_r_offset());
1178 // Create a GOT entry for the tp-relative offset.
1179 Output_data_got<32, false>* got
1180 = target->got_section(symtab, layout);
1181 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1182 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1183 ? elfcpp::R_386_TLS_TPOFF32
1184 : elfcpp::R_386_TLS_TPOFF);
1185 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1186 ? GOT_TYPE_TLS_OFFSET
1187 : GOT_TYPE_TLS_NOFFSET);
1188 got->add_local_with_rel(object, r_sym, got_type,
1189 target->rel_dyn_section(layout),
1192 else if (optimized_type != tls::TLSOPT_TO_LE)
1193 unsupported_reloc_local(object, r_type);
1196 case elfcpp::R_386_TLS_LE: // Local-exec
1197 case elfcpp::R_386_TLS_LE_32:
1198 layout->set_has_static_tls();
1199 if (output_is_shared)
1201 // We need to create a dynamic relocation.
1202 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1203 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1204 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1205 ? elfcpp::R_386_TLS_TPOFF32
1206 : elfcpp::R_386_TLS_TPOFF);
1207 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1208 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1209 data_shndx, reloc.get_r_offset());
1219 case elfcpp::R_386_32PLT:
1220 case elfcpp::R_386_TLS_GD_32:
1221 case elfcpp::R_386_TLS_GD_PUSH:
1222 case elfcpp::R_386_TLS_GD_CALL:
1223 case elfcpp::R_386_TLS_GD_POP:
1224 case elfcpp::R_386_TLS_LDM_32:
1225 case elfcpp::R_386_TLS_LDM_PUSH:
1226 case elfcpp::R_386_TLS_LDM_CALL:
1227 case elfcpp::R_386_TLS_LDM_POP:
1228 case elfcpp::R_386_USED_BY_INTEL_200:
1230 unsupported_reloc_local(object, r_type);
1235 // Report an unsupported relocation against a global symbol.
1238 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1239 unsigned int r_type,
1242 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1243 object->name().c_str(), r_type, gsym->demangled_name().c_str());
1247 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1251 case elfcpp::R_386_32:
1252 case elfcpp::R_386_16:
1253 case elfcpp::R_386_8:
1254 case elfcpp::R_386_GOTOFF:
1255 case elfcpp::R_386_GOT32:
1266 Target_i386::Scan::local_reloc_may_be_function_pointer(
1270 Sized_relobj<32, false>* ,
1273 const elfcpp::Rel<32, false>& ,
1274 unsigned int r_type,
1275 const elfcpp::Sym<32, false>&)
1277 return possible_function_pointer_reloc(r_type);
1281 Target_i386::Scan::global_reloc_may_be_function_pointer(
1285 Sized_relobj<32, false>* ,
1288 const elfcpp::Rel<32, false>& ,
1289 unsigned int r_type,
1292 return possible_function_pointer_reloc(r_type);
1295 // Scan a relocation for a global symbol.
1298 Target_i386::Scan::global(Symbol_table* symtab,
1300 Target_i386* target,
1301 Sized_relobj<32, false>* object,
1302 unsigned int data_shndx,
1303 Output_section* output_section,
1304 const elfcpp::Rel<32, false>& reloc,
1305 unsigned int r_type,
1310 case elfcpp::R_386_NONE:
1311 case elfcpp::R_386_GNU_VTINHERIT:
1312 case elfcpp::R_386_GNU_VTENTRY:
1315 case elfcpp::R_386_32:
1316 case elfcpp::R_386_16:
1317 case elfcpp::R_386_8:
1319 // Make a PLT entry if necessary.
1320 if (gsym->needs_plt_entry())
1322 target->make_plt_entry(symtab, layout, gsym);
1323 // Since this is not a PC-relative relocation, we may be
1324 // taking the address of a function. In that case we need to
1325 // set the entry in the dynamic symbol table to the address of
1327 if (gsym->is_from_dynobj() && !parameters->options().shared())
1328 gsym->set_needs_dynsym_value();
1330 // Make a dynamic relocation if necessary.
1331 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1333 if (gsym->may_need_copy_reloc())
1335 target->copy_reloc(symtab, layout, object,
1336 data_shndx, output_section, gsym, reloc);
1338 else if (r_type == elfcpp::R_386_32
1339 && gsym->can_use_relative_reloc(false))
1341 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1342 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1343 output_section, object,
1344 data_shndx, reloc.get_r_offset());
1348 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1349 rel_dyn->add_global(gsym, r_type, output_section, object,
1350 data_shndx, reloc.get_r_offset());
1356 case elfcpp::R_386_PC32:
1357 case elfcpp::R_386_PC16:
1358 case elfcpp::R_386_PC8:
1360 // Make a PLT entry if necessary.
1361 if (gsym->needs_plt_entry())
1363 // These relocations are used for function calls only in
1364 // non-PIC code. For a 32-bit relocation in a shared library,
1365 // we'll need a text relocation anyway, so we can skip the
1366 // PLT entry and let the dynamic linker bind the call directly
1367 // to the target. For smaller relocations, we should use a
1368 // PLT entry to ensure that the call can reach.
1369 if (!parameters->options().shared()
1370 || r_type != elfcpp::R_386_PC32)
1371 target->make_plt_entry(symtab, layout, gsym);
1373 // Make a dynamic relocation if necessary.
1374 int flags = Symbol::NON_PIC_REF;
1375 if (gsym->is_func())
1376 flags |= Symbol::FUNCTION_CALL;
1377 if (gsym->needs_dynamic_reloc(flags))
1379 if (gsym->may_need_copy_reloc())
1381 target->copy_reloc(symtab, layout, object,
1382 data_shndx, output_section, gsym, reloc);
1386 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1387 rel_dyn->add_global(gsym, r_type, output_section, object,
1388 data_shndx, reloc.get_r_offset());
1394 case elfcpp::R_386_GOT32:
1396 // The symbol requires a GOT entry.
1397 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1398 if (gsym->final_value_is_known())
1399 got->add_global(gsym, GOT_TYPE_STANDARD);
1402 // If this symbol is not fully resolved, we need to add a
1403 // GOT entry with a dynamic relocation.
1404 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1405 if (gsym->is_from_dynobj()
1406 || gsym->is_undefined()
1407 || gsym->is_preemptible())
1408 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1409 rel_dyn, elfcpp::R_386_GLOB_DAT);
1412 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1413 rel_dyn->add_global_relative(
1414 gsym, elfcpp::R_386_RELATIVE, got,
1415 gsym->got_offset(GOT_TYPE_STANDARD));
1421 case elfcpp::R_386_PLT32:
1422 // If the symbol is fully resolved, this is just a PC32 reloc.
1423 // Otherwise we need a PLT entry.
1424 if (gsym->final_value_is_known())
1426 // If building a shared library, we can also skip the PLT entry
1427 // if the symbol is defined in the output file and is protected
1429 if (gsym->is_defined()
1430 && !gsym->is_from_dynobj()
1431 && !gsym->is_preemptible())
1433 target->make_plt_entry(symtab, layout, gsym);
1436 case elfcpp::R_386_GOTOFF:
1437 case elfcpp::R_386_GOTPC:
1438 // We need a GOT section.
1439 target->got_section(symtab, layout);
1442 // These are relocations which should only be seen by the
1443 // dynamic linker, and should never be seen here.
1444 case elfcpp::R_386_COPY:
1445 case elfcpp::R_386_GLOB_DAT:
1446 case elfcpp::R_386_JUMP_SLOT:
1447 case elfcpp::R_386_RELATIVE:
1448 case elfcpp::R_386_TLS_TPOFF:
1449 case elfcpp::R_386_TLS_DTPMOD32:
1450 case elfcpp::R_386_TLS_DTPOFF32:
1451 case elfcpp::R_386_TLS_TPOFF32:
1452 case elfcpp::R_386_TLS_DESC:
1453 gold_error(_("%s: unexpected reloc %u in object file"),
1454 object->name().c_str(), r_type);
1457 // These are initial tls relocs, which are expected when
1459 case elfcpp::R_386_TLS_GD: // Global-dynamic
1460 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1461 case elfcpp::R_386_TLS_DESC_CALL:
1462 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1463 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1464 case elfcpp::R_386_TLS_IE: // Initial-exec
1465 case elfcpp::R_386_TLS_IE_32:
1466 case elfcpp::R_386_TLS_GOTIE:
1467 case elfcpp::R_386_TLS_LE: // Local-exec
1468 case elfcpp::R_386_TLS_LE_32:
1470 const bool is_final = gsym->final_value_is_known();
1471 const tls::Tls_optimization optimized_type
1472 = Target_i386::optimize_tls_reloc(is_final, r_type);
1475 case elfcpp::R_386_TLS_GD: // Global-dynamic
1476 if (optimized_type == tls::TLSOPT_NONE)
1478 // Create a pair of GOT entries for the module index and
1479 // dtv-relative offset.
1480 Output_data_got<32, false>* got
1481 = target->got_section(symtab, layout);
1482 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1483 target->rel_dyn_section(layout),
1484 elfcpp::R_386_TLS_DTPMOD32,
1485 elfcpp::R_386_TLS_DTPOFF32);
1487 else if (optimized_type == tls::TLSOPT_TO_IE)
1489 // Create a GOT entry for the tp-relative offset.
1490 Output_data_got<32, false>* got
1491 = target->got_section(symtab, layout);
1492 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1493 target->rel_dyn_section(layout),
1494 elfcpp::R_386_TLS_TPOFF);
1496 else if (optimized_type != tls::TLSOPT_TO_LE)
1497 unsupported_reloc_global(object, r_type, gsym);
1500 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
1501 target->define_tls_base_symbol(symtab, layout);
1502 if (optimized_type == tls::TLSOPT_NONE)
1504 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1505 Output_data_got<32, false>* got
1506 = target->got_section(symtab, layout);
1507 Reloc_section* rt = target->rel_tls_desc_section(layout);
1508 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
1509 elfcpp::R_386_TLS_DESC, 0);
1511 else if (optimized_type == tls::TLSOPT_TO_IE)
1513 // Create a GOT entry for the tp-relative offset.
1514 Output_data_got<32, false>* got
1515 = target->got_section(symtab, layout);
1516 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1517 target->rel_dyn_section(layout),
1518 elfcpp::R_386_TLS_TPOFF);
1520 else if (optimized_type != tls::TLSOPT_TO_LE)
1521 unsupported_reloc_global(object, r_type, gsym);
1524 case elfcpp::R_386_TLS_DESC_CALL:
1527 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1528 if (optimized_type == tls::TLSOPT_NONE)
1530 // Create a GOT entry for the module index.
1531 target->got_mod_index_entry(symtab, layout, object);
1533 else if (optimized_type != tls::TLSOPT_TO_LE)
1534 unsupported_reloc_global(object, r_type, gsym);
1537 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1540 case elfcpp::R_386_TLS_IE: // Initial-exec
1541 case elfcpp::R_386_TLS_IE_32:
1542 case elfcpp::R_386_TLS_GOTIE:
1543 layout->set_has_static_tls();
1544 if (optimized_type == tls::TLSOPT_NONE)
1546 // For the R_386_TLS_IE relocation, we need to create a
1547 // dynamic relocation when building a shared library.
1548 if (r_type == elfcpp::R_386_TLS_IE
1549 && parameters->options().shared())
1551 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1552 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1553 output_section, object,
1555 reloc.get_r_offset());
1557 // Create a GOT entry for the tp-relative offset.
1558 Output_data_got<32, false>* got
1559 = target->got_section(symtab, layout);
1560 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1561 ? elfcpp::R_386_TLS_TPOFF32
1562 : elfcpp::R_386_TLS_TPOFF);
1563 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1564 ? GOT_TYPE_TLS_OFFSET
1565 : GOT_TYPE_TLS_NOFFSET);
1566 got->add_global_with_rel(gsym, got_type,
1567 target->rel_dyn_section(layout),
1570 else if (optimized_type != tls::TLSOPT_TO_LE)
1571 unsupported_reloc_global(object, r_type, gsym);
1574 case elfcpp::R_386_TLS_LE: // Local-exec
1575 case elfcpp::R_386_TLS_LE_32:
1576 layout->set_has_static_tls();
1577 if (parameters->options().shared())
1579 // We need to create a dynamic relocation.
1580 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1581 ? elfcpp::R_386_TLS_TPOFF32
1582 : elfcpp::R_386_TLS_TPOFF);
1583 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1584 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1585 data_shndx, reloc.get_r_offset());
1595 case elfcpp::R_386_32PLT:
1596 case elfcpp::R_386_TLS_GD_32:
1597 case elfcpp::R_386_TLS_GD_PUSH:
1598 case elfcpp::R_386_TLS_GD_CALL:
1599 case elfcpp::R_386_TLS_GD_POP:
1600 case elfcpp::R_386_TLS_LDM_32:
1601 case elfcpp::R_386_TLS_LDM_PUSH:
1602 case elfcpp::R_386_TLS_LDM_CALL:
1603 case elfcpp::R_386_TLS_LDM_POP:
1604 case elfcpp::R_386_USED_BY_INTEL_200:
1606 unsupported_reloc_global(object, r_type, gsym);
1611 // Process relocations for gc.
1614 Target_i386::gc_process_relocs(Symbol_table* symtab,
1616 Sized_relobj<32, false>* object,
1617 unsigned int data_shndx,
1619 const unsigned char* prelocs,
1621 Output_section* output_section,
1622 bool needs_special_offset_handling,
1623 size_t local_symbol_count,
1624 const unsigned char* plocal_symbols)
1626 gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1628 Target_i386::Relocatable_size_for_reloc>(
1637 needs_special_offset_handling,
1642 // Scan relocations for a section.
1645 Target_i386::scan_relocs(Symbol_table* symtab,
1647 Sized_relobj<32, false>* object,
1648 unsigned int data_shndx,
1649 unsigned int sh_type,
1650 const unsigned char* prelocs,
1652 Output_section* output_section,
1653 bool needs_special_offset_handling,
1654 size_t local_symbol_count,
1655 const unsigned char* plocal_symbols)
1657 if (sh_type == elfcpp::SHT_RELA)
1659 gold_error(_("%s: unsupported RELA reloc section"),
1660 object->name().c_str());
1664 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1674 needs_special_offset_handling,
1679 // Finalize the sections.
1682 Target_i386::do_finalize_sections(
1684 const Input_objects*,
1685 Symbol_table* symtab)
1687 const Reloc_section* rel_plt = (this->plt_ == NULL
1689 : this->plt_->rel_plt());
1690 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
1691 this->rel_dyn_, true, false);
1693 // Emit any relocs we saved in an attempt to avoid generating COPY
1695 if (this->copy_relocs_.any_saved_relocs())
1696 this->copy_relocs_.emit(this->rel_dyn_section(layout));
1698 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1699 // the .got.plt section.
1700 Symbol* sym = this->global_offset_table_;
1703 uint32_t data_size = this->got_plt_->current_data_size();
1704 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
1708 // Return whether a direct absolute static relocation needs to be applied.
1709 // In cases where Scan::local() or Scan::global() has created
1710 // a dynamic relocation other than R_386_RELATIVE, the addend
1711 // of the relocation is carried in the data, and we must not
1712 // apply the static relocation.
1715 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1718 Output_section* output_section)
1720 // If the output section is not allocated, then we didn't call
1721 // scan_relocs, we didn't create a dynamic reloc, and we must apply
1723 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1726 // For local symbols, we will have created a non-RELATIVE dynamic
1727 // relocation only if (a) the output is position independent,
1728 // (b) the relocation is absolute (not pc- or segment-relative), and
1729 // (c) the relocation is not 32 bits wide.
1731 return !(parameters->options().output_is_position_independent()
1732 && (ref_flags & Symbol::ABSOLUTE_REF)
1735 // For global symbols, we use the same helper routines used in the
1736 // scan pass. If we did not create a dynamic relocation, or if we
1737 // created a RELATIVE dynamic relocation, we should apply the static
1739 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1740 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1741 && gsym->can_use_relative_reloc(ref_flags
1742 & Symbol::FUNCTION_CALL);
1743 return !has_dyn || is_rel;
1746 // Perform a relocation.
1749 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1750 Target_i386* target,
1751 Output_section *output_section,
1753 const elfcpp::Rel<32, false>& rel,
1754 unsigned int r_type,
1755 const Sized_symbol<32>* gsym,
1756 const Symbol_value<32>* psymval,
1757 unsigned char* view,
1758 elfcpp::Elf_types<32>::Elf_Addr address,
1759 section_size_type view_size)
1761 if (this->skip_call_tls_get_addr_)
1763 if ((r_type != elfcpp::R_386_PLT32
1764 && r_type != elfcpp::R_386_PC32)
1766 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1767 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1768 _("missing expected TLS relocation"));
1771 this->skip_call_tls_get_addr_ = false;
1776 // Pick the value to use for symbols defined in shared objects.
1777 Symbol_value<32> symval;
1779 && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1780 || r_type == elfcpp::R_386_PC16
1781 || r_type == elfcpp::R_386_PC32))
1783 symval.set_output_value(target->plt_section()->address()
1784 + gsym->plt_offset());
1788 const Sized_relobj<32, false>* object = relinfo->object;
1790 // Get the GOT offset if needed.
1791 // The GOT pointer points to the end of the GOT section.
1792 // We need to subtract the size of the GOT section to get
1793 // the actual offset to use in the relocation.
1794 bool have_got_offset = false;
1795 unsigned int got_offset = 0;
1798 case elfcpp::R_386_GOT32:
1801 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1802 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1803 - target->got_size());
1807 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1808 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1809 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1810 - target->got_size());
1812 have_got_offset = true;
1821 case elfcpp::R_386_NONE:
1822 case elfcpp::R_386_GNU_VTINHERIT:
1823 case elfcpp::R_386_GNU_VTENTRY:
1826 case elfcpp::R_386_32:
1827 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1829 Relocate_functions<32, false>::rel32(view, object, psymval);
1832 case elfcpp::R_386_PC32:
1834 int ref_flags = Symbol::NON_PIC_REF;
1835 if (gsym != NULL && gsym->is_func())
1836 ref_flags |= Symbol::FUNCTION_CALL;
1837 if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1838 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1842 case elfcpp::R_386_16:
1843 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1845 Relocate_functions<32, false>::rel16(view, object, psymval);
1848 case elfcpp::R_386_PC16:
1850 int ref_flags = Symbol::NON_PIC_REF;
1851 if (gsym != NULL && gsym->is_func())
1852 ref_flags |= Symbol::FUNCTION_CALL;
1853 if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1854 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1858 case elfcpp::R_386_8:
1859 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1861 Relocate_functions<32, false>::rel8(view, object, psymval);
1864 case elfcpp::R_386_PC8:
1866 int ref_flags = Symbol::NON_PIC_REF;
1867 if (gsym != NULL && gsym->is_func())
1868 ref_flags |= Symbol::FUNCTION_CALL;
1869 if (should_apply_static_reloc(gsym, ref_flags, false,
1871 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1875 case elfcpp::R_386_PLT32:
1876 gold_assert(gsym == NULL
1877 || gsym->has_plt_offset()
1878 || gsym->final_value_is_known()
1879 || (gsym->is_defined()
1880 && !gsym->is_from_dynobj()
1881 && !gsym->is_preemptible()));
1882 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1885 case elfcpp::R_386_GOT32:
1886 gold_assert(have_got_offset);
1887 Relocate_functions<32, false>::rel32(view, got_offset);
1890 case elfcpp::R_386_GOTOFF:
1892 elfcpp::Elf_types<32>::Elf_Addr value;
1893 value = (psymval->value(object, 0)
1894 - target->got_plt_section()->address());
1895 Relocate_functions<32, false>::rel32(view, value);
1899 case elfcpp::R_386_GOTPC:
1901 elfcpp::Elf_types<32>::Elf_Addr value;
1902 value = target->got_plt_section()->address();
1903 Relocate_functions<32, false>::pcrel32(view, value, address);
1907 case elfcpp::R_386_COPY:
1908 case elfcpp::R_386_GLOB_DAT:
1909 case elfcpp::R_386_JUMP_SLOT:
1910 case elfcpp::R_386_RELATIVE:
1911 // These are outstanding tls relocs, which are unexpected when
1913 case elfcpp::R_386_TLS_TPOFF:
1914 case elfcpp::R_386_TLS_DTPMOD32:
1915 case elfcpp::R_386_TLS_DTPOFF32:
1916 case elfcpp::R_386_TLS_TPOFF32:
1917 case elfcpp::R_386_TLS_DESC:
1918 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1919 _("unexpected reloc %u in object file"),
1923 // These are initial tls relocs, which are expected when
1925 case elfcpp::R_386_TLS_GD: // Global-dynamic
1926 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1927 case elfcpp::R_386_TLS_DESC_CALL:
1928 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1929 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1930 case elfcpp::R_386_TLS_IE: // Initial-exec
1931 case elfcpp::R_386_TLS_IE_32:
1932 case elfcpp::R_386_TLS_GOTIE:
1933 case elfcpp::R_386_TLS_LE: // Local-exec
1934 case elfcpp::R_386_TLS_LE_32:
1935 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1936 view, address, view_size);
1939 case elfcpp::R_386_32PLT:
1940 case elfcpp::R_386_TLS_GD_32:
1941 case elfcpp::R_386_TLS_GD_PUSH:
1942 case elfcpp::R_386_TLS_GD_CALL:
1943 case elfcpp::R_386_TLS_GD_POP:
1944 case elfcpp::R_386_TLS_LDM_32:
1945 case elfcpp::R_386_TLS_LDM_PUSH:
1946 case elfcpp::R_386_TLS_LDM_CALL:
1947 case elfcpp::R_386_TLS_LDM_POP:
1948 case elfcpp::R_386_USED_BY_INTEL_200:
1950 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1951 _("unsupported reloc %u"),
1959 // Perform a TLS relocation.
1962 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1963 Target_i386* target,
1965 const elfcpp::Rel<32, false>& rel,
1966 unsigned int r_type,
1967 const Sized_symbol<32>* gsym,
1968 const Symbol_value<32>* psymval,
1969 unsigned char* view,
1970 elfcpp::Elf_types<32>::Elf_Addr,
1971 section_size_type view_size)
1973 Output_segment* tls_segment = relinfo->layout->tls_segment();
1975 const Sized_relobj<32, false>* object = relinfo->object;
1977 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1979 const bool is_final = (gsym == NULL
1980 ? !parameters->options().shared()
1981 : gsym->final_value_is_known());
1982 const tls::Tls_optimization optimized_type
1983 = Target_i386::optimize_tls_reloc(is_final, r_type);
1986 case elfcpp::R_386_TLS_GD: // Global-dynamic
1987 if (optimized_type == tls::TLSOPT_TO_LE)
1989 gold_assert(tls_segment != NULL);
1990 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1991 rel, r_type, value, view,
1997 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1998 ? GOT_TYPE_TLS_NOFFSET
1999 : GOT_TYPE_TLS_PAIR);
2000 unsigned int got_offset;
2003 gold_assert(gsym->has_got_offset(got_type));
2004 got_offset = gsym->got_offset(got_type) - target->got_size();
2008 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2009 gold_assert(object->local_has_got_offset(r_sym, got_type));
2010 got_offset = (object->local_got_offset(r_sym, got_type)
2011 - target->got_size());
2013 if (optimized_type == tls::TLSOPT_TO_IE)
2015 gold_assert(tls_segment != NULL);
2016 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2017 got_offset, view, view_size);
2020 else if (optimized_type == tls::TLSOPT_NONE)
2022 // Relocate the field with the offset of the pair of GOT
2024 Relocate_functions<32, false>::rel32(view, got_offset);
2028 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2029 _("unsupported reloc %u"),
2033 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2034 case elfcpp::R_386_TLS_DESC_CALL:
2035 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2036 if (optimized_type == tls::TLSOPT_TO_LE)
2038 gold_assert(tls_segment != NULL);
2039 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2040 rel, r_type, value, view,
2046 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2047 ? GOT_TYPE_TLS_NOFFSET
2048 : GOT_TYPE_TLS_DESC);
2049 unsigned int got_offset;
2052 gold_assert(gsym->has_got_offset(got_type));
2053 got_offset = gsym->got_offset(got_type) - target->got_size();
2057 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2058 gold_assert(object->local_has_got_offset(r_sym, got_type));
2059 got_offset = (object->local_got_offset(r_sym, got_type)
2060 - target->got_size());
2062 if (optimized_type == tls::TLSOPT_TO_IE)
2064 gold_assert(tls_segment != NULL);
2065 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2066 got_offset, view, view_size);
2069 else if (optimized_type == tls::TLSOPT_NONE)
2071 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2073 // Relocate the field with the offset of the pair of GOT
2075 Relocate_functions<32, false>::rel32(view, got_offset);
2080 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2081 _("unsupported reloc %u"),
2085 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2086 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2088 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2089 _("both SUN and GNU model "
2090 "TLS relocations"));
2093 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2094 if (optimized_type == tls::TLSOPT_TO_LE)
2096 gold_assert(tls_segment != NULL);
2097 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2098 value, view, view_size);
2101 else if (optimized_type == tls::TLSOPT_NONE)
2103 // Relocate the field with the offset of the GOT entry for
2104 // the module index.
2105 unsigned int got_offset;
2106 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2107 - target->got_size());
2108 Relocate_functions<32, false>::rel32(view, got_offset);
2111 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2112 _("unsupported reloc %u"),
2116 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2117 if (optimized_type == tls::TLSOPT_TO_LE)
2119 // This reloc can appear in debugging sections, in which
2120 // case we must not convert to local-exec. We decide what
2121 // to do based on whether the section is marked as
2122 // containing executable code. That is what the GNU linker
2124 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2125 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2127 gold_assert(tls_segment != NULL);
2128 value -= tls_segment->memsz();
2131 Relocate_functions<32, false>::rel32(view, value);
2134 case elfcpp::R_386_TLS_IE: // Initial-exec
2135 case elfcpp::R_386_TLS_GOTIE:
2136 case elfcpp::R_386_TLS_IE_32:
2137 if (optimized_type == tls::TLSOPT_TO_LE)
2139 gold_assert(tls_segment != NULL);
2140 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2141 rel, r_type, value, view,
2145 else if (optimized_type == tls::TLSOPT_NONE)
2147 // Relocate the field with the offset of the GOT entry for
2148 // the tp-relative offset of the symbol.
2149 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2150 ? GOT_TYPE_TLS_OFFSET
2151 : GOT_TYPE_TLS_NOFFSET);
2152 unsigned int got_offset;
2155 gold_assert(gsym->has_got_offset(got_type));
2156 got_offset = gsym->got_offset(got_type);
2160 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2161 gold_assert(object->local_has_got_offset(r_sym, got_type));
2162 got_offset = object->local_got_offset(r_sym, got_type);
2164 // For the R_386_TLS_IE relocation, we need to apply the
2165 // absolute address of the GOT entry.
2166 if (r_type == elfcpp::R_386_TLS_IE)
2167 got_offset += target->got_plt_section()->address();
2168 // All GOT offsets are relative to the end of the GOT.
2169 got_offset -= target->got_size();
2170 Relocate_functions<32, false>::rel32(view, got_offset);
2173 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2174 _("unsupported reloc %u"),
2178 case elfcpp::R_386_TLS_LE: // Local-exec
2179 // If we're creating a shared library, a dynamic relocation will
2180 // have been created for this location, so do not apply it now.
2181 if (!parameters->options().shared())
2183 gold_assert(tls_segment != NULL);
2184 value -= tls_segment->memsz();
2185 Relocate_functions<32, false>::rel32(view, value);
2189 case elfcpp::R_386_TLS_LE_32:
2190 // If we're creating a shared library, a dynamic relocation will
2191 // have been created for this location, so do not apply it now.
2192 if (!parameters->options().shared())
2194 gold_assert(tls_segment != NULL);
2195 value = tls_segment->memsz() - value;
2196 Relocate_functions<32, false>::rel32(view, value);
2202 // Do a relocation in which we convert a TLS General-Dynamic to a
2206 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2208 Output_segment* tls_segment,
2209 const elfcpp::Rel<32, false>& rel,
2211 elfcpp::Elf_types<32>::Elf_Addr value,
2212 unsigned char* view,
2213 section_size_type view_size)
2215 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2216 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2217 // leal foo(%reg),%eax; call ___tls_get_addr
2218 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2220 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2221 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2223 unsigned char op1 = view[-1];
2224 unsigned char op2 = view[-2];
2226 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2227 op2 == 0x8d || op2 == 0x04);
2228 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2234 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2235 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2236 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2237 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2238 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2242 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2243 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2244 if (rel.get_r_offset() + 9 < view_size
2247 // There is a trailing nop. Use the size byte subl.
2248 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2253 // Use the five byte subl.
2254 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2258 value = tls_segment->memsz() - value;
2259 Relocate_functions<32, false>::rel32(view + roff, value);
2261 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2263 this->skip_call_tls_get_addr_ = true;
2266 // Do a relocation in which we convert a TLS General-Dynamic to an
2270 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2273 const elfcpp::Rel<32, false>& rel,
2275 elfcpp::Elf_types<32>::Elf_Addr value,
2276 unsigned char* view,
2277 section_size_type view_size)
2279 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2280 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2282 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2283 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2285 unsigned char op1 = view[-1];
2286 unsigned char op2 = view[-2];
2288 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2289 op2 == 0x8d || op2 == 0x04);
2290 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2294 // FIXME: For now, support only the first (SIB) form.
2295 tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2299 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2300 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2301 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2302 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2303 memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2307 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2308 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2309 if (rel.get_r_offset() + 9 < view_size
2312 // FIXME: This is not the right instruction sequence.
2313 // There is a trailing nop. Use the size byte subl.
2314 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2319 // FIXME: This is not the right instruction sequence.
2320 // Use the five byte subl.
2321 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2325 Relocate_functions<32, false>::rel32(view + roff, value);
2327 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2329 this->skip_call_tls_get_addr_ = true;
2332 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2333 // General-Dynamic to a Local-Exec.
2336 Target_i386::Relocate::tls_desc_gd_to_le(
2337 const Relocate_info<32, false>* relinfo,
2339 Output_segment* tls_segment,
2340 const elfcpp::Rel<32, false>& rel,
2341 unsigned int r_type,
2342 elfcpp::Elf_types<32>::Elf_Addr value,
2343 unsigned char* view,
2344 section_size_type view_size)
2346 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2348 // leal foo@TLSDESC(%ebx), %eax
2349 // ==> leal foo@NTPOFF, %eax
2350 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2351 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2352 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2353 view[-2] == 0x8d && view[-1] == 0x83);
2355 value -= tls_segment->memsz();
2356 Relocate_functions<32, false>::rel32(view, value);
2360 // call *foo@TLSCALL(%eax)
2362 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2363 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2364 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2365 view[0] == 0xff && view[1] == 0x10);
2371 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2372 // General-Dynamic to an Initial-Exec.
2375 Target_i386::Relocate::tls_desc_gd_to_ie(
2376 const Relocate_info<32, false>* relinfo,
2379 const elfcpp::Rel<32, false>& rel,
2380 unsigned int r_type,
2381 elfcpp::Elf_types<32>::Elf_Addr value,
2382 unsigned char* view,
2383 section_size_type view_size)
2385 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2387 // leal foo@TLSDESC(%ebx), %eax
2388 // ==> movl foo@GOTNTPOFF(%ebx), %eax
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);
2391 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2392 view[-2] == 0x8d && view[-1] == 0x83);
2394 Relocate_functions<32, false>::rel32(view, value);
2398 // call *foo@TLSCALL(%eax)
2400 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2401 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2402 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2403 view[0] == 0xff && view[1] == 0x10);
2409 // Do a relocation in which we convert a TLS Local-Dynamic to a
2413 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2416 const elfcpp::Rel<32, false>& rel,
2418 elfcpp::Elf_types<32>::Elf_Addr,
2419 unsigned char* view,
2420 section_size_type view_size)
2422 // leal foo(%reg), %eax; call ___tls_get_addr
2423 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2425 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2426 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2428 // FIXME: Does this test really always pass?
2429 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2430 view[-2] == 0x8d && view[-1] == 0x83);
2432 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2434 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2436 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2438 this->skip_call_tls_get_addr_ = true;
2441 // Do a relocation in which we convert a TLS Initial-Exec to a
2445 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2447 Output_segment* tls_segment,
2448 const elfcpp::Rel<32, false>& rel,
2449 unsigned int r_type,
2450 elfcpp::Elf_types<32>::Elf_Addr value,
2451 unsigned char* view,
2452 section_size_type view_size)
2454 // We have to actually change the instructions, which means that we
2455 // need to examine the opcodes to figure out which instruction we
2457 if (r_type == elfcpp::R_386_TLS_IE)
2459 // movl %gs:XX,%eax ==> movl $YY,%eax
2460 // movl %gs:XX,%reg ==> movl $YY,%reg
2461 // addl %gs:XX,%reg ==> addl $YY,%reg
2462 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2463 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2465 unsigned char op1 = view[-1];
2468 // movl XX,%eax ==> movl $YY,%eax
2473 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2475 unsigned char op2 = view[-2];
2478 // movl XX,%reg ==> movl $YY,%reg
2479 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2480 (op1 & 0xc7) == 0x05);
2482 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2484 else if (op2 == 0x03)
2486 // addl XX,%reg ==> addl $YY,%reg
2487 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2488 (op1 & 0xc7) == 0x05);
2490 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2493 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2498 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2499 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2500 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2501 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2502 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2504 unsigned char op1 = view[-1];
2505 unsigned char op2 = view[-2];
2506 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2507 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2510 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2512 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2514 else if (op2 == 0x2b)
2516 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2518 view[-1] = 0xe8 | ((op1 >> 3) & 7);
2520 else if (op2 == 0x03)
2522 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2524 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2527 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2530 value = tls_segment->memsz() - value;
2531 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2534 Relocate_functions<32, false>::rel32(view, value);
2537 // Relocate section data.
2540 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2541 unsigned int sh_type,
2542 const unsigned char* prelocs,
2544 Output_section* output_section,
2545 bool needs_special_offset_handling,
2546 unsigned char* view,
2547 elfcpp::Elf_types<32>::Elf_Addr address,
2548 section_size_type view_size,
2549 const Reloc_symbol_changes* reloc_symbol_changes)
2551 gold_assert(sh_type == elfcpp::SHT_REL);
2553 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2554 Target_i386::Relocate>(
2560 needs_special_offset_handling,
2564 reloc_symbol_changes);
2567 // Return the size of a relocation while scanning during a relocatable
2571 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2572 unsigned int r_type,
2577 case elfcpp::R_386_NONE:
2578 case elfcpp::R_386_GNU_VTINHERIT:
2579 case elfcpp::R_386_GNU_VTENTRY:
2580 case elfcpp::R_386_TLS_GD: // Global-dynamic
2581 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2582 case elfcpp::R_386_TLS_DESC_CALL:
2583 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2584 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2585 case elfcpp::R_386_TLS_IE: // Initial-exec
2586 case elfcpp::R_386_TLS_IE_32:
2587 case elfcpp::R_386_TLS_GOTIE:
2588 case elfcpp::R_386_TLS_LE: // Local-exec
2589 case elfcpp::R_386_TLS_LE_32:
2592 case elfcpp::R_386_32:
2593 case elfcpp::R_386_PC32:
2594 case elfcpp::R_386_GOT32:
2595 case elfcpp::R_386_PLT32:
2596 case elfcpp::R_386_GOTOFF:
2597 case elfcpp::R_386_GOTPC:
2600 case elfcpp::R_386_16:
2601 case elfcpp::R_386_PC16:
2604 case elfcpp::R_386_8:
2605 case elfcpp::R_386_PC8:
2608 // These are relocations which should only be seen by the
2609 // dynamic linker, and should never be seen here.
2610 case elfcpp::R_386_COPY:
2611 case elfcpp::R_386_GLOB_DAT:
2612 case elfcpp::R_386_JUMP_SLOT:
2613 case elfcpp::R_386_RELATIVE:
2614 case elfcpp::R_386_TLS_TPOFF:
2615 case elfcpp::R_386_TLS_DTPMOD32:
2616 case elfcpp::R_386_TLS_DTPOFF32:
2617 case elfcpp::R_386_TLS_TPOFF32:
2618 case elfcpp::R_386_TLS_DESC:
2619 object->error(_("unexpected reloc %u in object file"), r_type);
2622 case elfcpp::R_386_32PLT:
2623 case elfcpp::R_386_TLS_GD_32:
2624 case elfcpp::R_386_TLS_GD_PUSH:
2625 case elfcpp::R_386_TLS_GD_CALL:
2626 case elfcpp::R_386_TLS_GD_POP:
2627 case elfcpp::R_386_TLS_LDM_32:
2628 case elfcpp::R_386_TLS_LDM_PUSH:
2629 case elfcpp::R_386_TLS_LDM_CALL:
2630 case elfcpp::R_386_TLS_LDM_POP:
2631 case elfcpp::R_386_USED_BY_INTEL_200:
2633 object->error(_("unsupported reloc %u in object file"), r_type);
2638 // Scan the relocs during a relocatable link.
2641 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
2643 Sized_relobj<32, false>* object,
2644 unsigned int data_shndx,
2645 unsigned int sh_type,
2646 const unsigned char* prelocs,
2648 Output_section* output_section,
2649 bool needs_special_offset_handling,
2650 size_t local_symbol_count,
2651 const unsigned char* plocal_symbols,
2652 Relocatable_relocs* rr)
2654 gold_assert(sh_type == elfcpp::SHT_REL);
2656 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2657 Relocatable_size_for_reloc> Scan_relocatable_relocs;
2659 gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2660 Scan_relocatable_relocs>(
2668 needs_special_offset_handling,
2674 // Relocate a section during a relocatable link.
2677 Target_i386::relocate_for_relocatable(
2678 const Relocate_info<32, false>* relinfo,
2679 unsigned int sh_type,
2680 const unsigned char* prelocs,
2682 Output_section* output_section,
2683 off_t offset_in_output_section,
2684 const Relocatable_relocs* rr,
2685 unsigned char* view,
2686 elfcpp::Elf_types<32>::Elf_Addr view_address,
2687 section_size_type view_size,
2688 unsigned char* reloc_view,
2689 section_size_type reloc_view_size)
2691 gold_assert(sh_type == elfcpp::SHT_REL);
2693 gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2698 offset_in_output_section,
2707 // Return the value to use for a dynamic which requires special
2708 // treatment. This is how we support equality comparisons of function
2709 // pointers across shared library boundaries, as described in the
2710 // processor specific ABI supplement.
2713 Target_i386::do_dynsym_value(const Symbol* gsym) const
2715 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2716 return this->plt_section()->address() + gsym->plt_offset();
2719 // Return a string used to fill a code section with nops to take up
2720 // the specified length.
2723 Target_i386::do_code_fill(section_size_type length) const
2727 // Build a jmp instruction to skip over the bytes.
2728 unsigned char jmp[5];
2730 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2731 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2732 + std::string(length - 5, '\0'));
2735 // Nop sequences of various lengths.
2736 const char nop1[1] = { 0x90 }; // nop
2737 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
2738 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2739 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2740 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2741 0x00 }; // leal 0(%esi,1),%esi
2742 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2744 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2746 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2747 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2748 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2749 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2751 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2752 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2754 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2755 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2757 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2758 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2759 0x00, 0x00, 0x00, 0x00 };
2760 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2761 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2762 0x27, 0x00, 0x00, 0x00,
2764 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2765 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2766 0xbc, 0x27, 0x00, 0x00,
2768 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2769 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2770 0x90, 0x90, 0x90, 0x90,
2773 const char* nops[16] = {
2775 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2776 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2779 return std::string(nops[length], length);
2782 // Return whether SYM should be treated as a call to a non-split
2783 // function. We don't want that to be true of a call to a
2784 // get_pc_thunk function.
2787 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
2789 return (sym->type() == elfcpp::STT_FUNC
2790 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
2793 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2794 // compiled with -fstack-split. The function calls non-stack-split
2795 // code. We have to change the function so that it always ensures
2796 // that it has enough stack space to run some random function.
2799 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
2800 section_offset_type fnoffset,
2801 section_size_type fnsize,
2802 unsigned char* view,
2803 section_size_type view_size,
2805 std::string* to) const
2807 // The function starts with a comparison of the stack pointer and a
2808 // field in the TCB. This is followed by a jump.
2811 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
2814 // We will call __morestack if the carry flag is set after this
2815 // comparison. We turn the comparison into an stc instruction
2817 view[fnoffset] = '\xf9';
2818 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
2820 // lea NN(%esp),%ecx
2821 // lea NN(%esp),%edx
2822 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
2823 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
2826 // This is loading an offset from the stack pointer for a
2827 // comparison. The offset is negative, so we decrease the
2828 // offset by the amount of space we need for the stack. This
2829 // means we will avoid calling __morestack if there happens to
2830 // be plenty of space on the stack already.
2831 unsigned char* pval = view + fnoffset + 3;
2832 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2833 val -= parameters->options().split_stack_adjust_size();
2834 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2838 if (!object->has_no_split_stack())
2839 object->error(_("failed to match split-stack sequence at "
2840 "section %u offset %0zx"),
2841 shndx, static_cast<size_t>(fnoffset));
2845 // We have to change the function so that it calls
2846 // __morestack_non_split instead of __morestack. The former will
2847 // allocate additional stack space.
2848 *from = "__morestack";
2849 *to = "__morestack_non_split";
2852 // The selector for i386 object files.
2854 class Target_selector_i386 : public Target_selector_freebsd
2857 Target_selector_i386()
2858 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2859 "elf32-i386", "elf32-i386-freebsd")
2863 do_instantiate_target()
2864 { return new Target_i386(); }
2867 Target_selector_i386 target_selector_i386;
2869 } // End anonymous namespace.