1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007 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"
36 #include "target-reloc.h"
37 #include "target-select.h"
45 class Output_data_plt_i386;
47 // The i386 target class.
48 // TLS info comes from
49 // http://people.redhat.com/drepper/tls.pdf
50 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
52 class Target_i386 : public Sized_target<32, false>
55 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
58 : Sized_target<32, false>(&i386_info),
59 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
60 copy_relocs_(NULL), dynbss_(NULL), got_mod_index_offset_(-1U)
63 // Scan the relocations to look for symbol adjustments.
65 scan_relocs(const General_options& options,
68 Sized_relobj<32, false>* object,
69 unsigned int data_shndx,
71 const unsigned char* prelocs,
73 Output_section* output_section,
74 bool needs_special_offset_handling,
75 size_t local_symbol_count,
76 const unsigned char* plocal_symbols);
78 // Finalize the sections.
80 do_finalize_sections(Layout*);
82 // Return the value to use for a dynamic which requires special
85 do_dynsym_value(const Symbol*) const;
87 // Relocate a section.
89 relocate_section(const Relocate_info<32, false>*,
91 const unsigned char* prelocs,
93 Output_section* output_section,
94 bool needs_special_offset_handling,
96 elfcpp::Elf_types<32>::Elf_Addr view_address,
97 section_size_type view_size);
99 // Scan the relocs during a relocatable link.
101 scan_relocatable_relocs(const General_options& options,
102 Symbol_table* symtab,
104 Sized_relobj<32, false>* object,
105 unsigned int data_shndx,
106 unsigned int sh_type,
107 const unsigned char* prelocs,
109 Output_section* output_section,
110 bool needs_special_offset_handling,
111 size_t local_symbol_count,
112 const unsigned char* plocal_symbols,
113 Relocatable_relocs*);
115 // Relocate a section during a relocatable link.
117 relocate_for_relocatable(const Relocate_info<32, false>*,
118 unsigned int sh_type,
119 const unsigned char* prelocs,
121 Output_section* output_section,
122 off_t offset_in_output_section,
123 const Relocatable_relocs*,
125 elfcpp::Elf_types<32>::Elf_Addr view_address,
126 section_size_type view_size,
127 unsigned char* reloc_view,
128 section_size_type reloc_view_size);
130 // Return a string used to fill a code section with nops.
132 do_code_fill(section_size_type length);
134 // Return whether SYM is defined by the ABI.
136 do_is_defined_by_abi(Symbol* sym) const
137 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
139 // Return the size of the GOT section.
143 gold_assert(this->got_ != NULL);
144 return this->got_->data_size();
148 // The class which scans relocations.
152 local(const General_options& options, Symbol_table* symtab,
153 Layout* layout, Target_i386* target,
154 Sized_relobj<32, false>* object,
155 unsigned int data_shndx,
156 Output_section* output_section,
157 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
158 const elfcpp::Sym<32, false>& lsym);
161 global(const General_options& options, Symbol_table* symtab,
162 Layout* layout, Target_i386* target,
163 Sized_relobj<32, false>* object,
164 unsigned int data_shndx,
165 Output_section* output_section,
166 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
170 unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
173 unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
177 // The class which implements relocation.
182 : skip_call_tls_get_addr_(false),
183 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
188 if (this->skip_call_tls_get_addr_)
190 // FIXME: This needs to specify the location somehow.
191 gold_error(_("missing expected TLS relocation"));
195 // Return whether the static relocation needs to be applied.
197 should_apply_static_reloc(const Sized_symbol<32>* gsym,
201 // Do a relocation. Return false if the caller should not issue
202 // any warnings about this relocation.
204 relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
205 const elfcpp::Rel<32, false>&,
206 unsigned int r_type, const Sized_symbol<32>*,
207 const Symbol_value<32>*,
208 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
212 // Do a TLS relocation.
214 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
215 size_t relnum, const elfcpp::Rel<32, false>&,
216 unsigned int r_type, const Sized_symbol<32>*,
217 const Symbol_value<32>*,
218 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
221 // Do a TLS General-Dynamic to Initial-Exec transition.
223 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
224 Output_segment* tls_segment,
225 const elfcpp::Rel<32, false>&, unsigned int r_type,
226 elfcpp::Elf_types<32>::Elf_Addr value,
228 section_size_type view_size);
230 // Do a TLS General-Dynamic to Local-Exec transition.
232 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
233 Output_segment* tls_segment,
234 const elfcpp::Rel<32, false>&, unsigned int r_type,
235 elfcpp::Elf_types<32>::Elf_Addr value,
237 section_size_type view_size);
239 // Do a TLS Local-Dynamic to Local-Exec transition.
241 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
242 Output_segment* tls_segment,
243 const elfcpp::Rel<32, false>&, unsigned int r_type,
244 elfcpp::Elf_types<32>::Elf_Addr value,
246 section_size_type view_size);
248 // Do a TLS Initial-Exec to Local-Exec transition.
250 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
251 Output_segment* tls_segment,
252 const elfcpp::Rel<32, false>&, unsigned int r_type,
253 elfcpp::Elf_types<32>::Elf_Addr value,
255 section_size_type view_size);
257 // We need to keep track of which type of local dynamic relocation
258 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
259 enum Local_dynamic_type
266 // This is set if we should skip the next reloc, which should be a
267 // PLT32 reloc against ___tls_get_addr.
268 bool skip_call_tls_get_addr_;
269 // The type of local dynamic relocation we have seen in the section
270 // being relocated, if any.
271 Local_dynamic_type local_dynamic_type_;
274 // A class which returns the size required for a relocation type,
275 // used while scanning relocs during a relocatable link.
276 class Relocatable_size_for_reloc
280 get_size_for_reloc(unsigned int, Relobj*);
283 // Adjust TLS relocation type based on the options and whether this
284 // is a local symbol.
285 static tls::Tls_optimization
286 optimize_tls_reloc(bool is_final, int r_type);
288 // Get the GOT section, creating it if necessary.
289 Output_data_got<32, false>*
290 got_section(Symbol_table*, Layout*);
292 // Get the GOT PLT section.
294 got_plt_section() const
296 gold_assert(this->got_plt_ != NULL);
297 return this->got_plt_;
300 // Create a PLT entry for a global symbol.
302 make_plt_entry(Symbol_table*, Layout*, Symbol*);
304 // Create a GOT entry for the TLS module index.
306 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
307 Sized_relobj<32, false>* object);
309 // Get the PLT section.
310 const Output_data_plt_i386*
313 gold_assert(this->plt_ != NULL);
317 // Get the dynamic reloc section, creating it if necessary.
319 rel_dyn_section(Layout*);
321 // Return true if the symbol may need a COPY relocation.
322 // References from an executable object to non-function symbols
323 // defined in a dynamic object may need a COPY relocation.
325 may_need_copy_reloc(Symbol* gsym)
327 return (!parameters->output_is_shared()
328 && gsym->is_from_dynobj()
329 && gsym->type() != elfcpp::STT_FUNC);
332 // Copy a relocation against a global symbol.
334 copy_reloc(const General_options*, Symbol_table*, Layout*,
335 Sized_relobj<32, false>*, unsigned int,
336 Output_section*, Symbol*, const elfcpp::Rel<32, false>&);
338 // Information about this specific target which we pass to the
339 // general Target structure.
340 static const Target::Target_info i386_info;
343 Output_data_got<32, false>* got_;
345 Output_data_plt_i386* plt_;
346 // The GOT PLT section.
347 Output_data_space* got_plt_;
348 // The dynamic reloc section.
349 Reloc_section* rel_dyn_;
350 // Relocs saved to avoid a COPY reloc.
351 Copy_relocs<32, false>* copy_relocs_;
352 // Space for variables copied with a COPY reloc.
353 Output_data_space* dynbss_;
354 // Offset of the GOT entry for the TLS module index;
355 unsigned int got_mod_index_offset_;
358 const Target::Target_info Target_i386::i386_info =
361 false, // is_big_endian
362 elfcpp::EM_386, // machine_code
363 false, // has_make_symbol
364 false, // has_resolve
365 true, // has_code_fill
366 true, // is_default_stack_executable
367 "/usr/lib/libc.so.1", // dynamic_linker
368 0x08048000, // default_text_segment_address
369 0x1000, // abi_pagesize (overridable by -z max-page-size)
370 0x1000 // common_pagesize (overridable by -z common-page-size)
373 // Get the GOT section, creating it if necessary.
375 Output_data_got<32, false>*
376 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
378 if (this->got_ == NULL)
380 gold_assert(symtab != NULL && layout != NULL);
382 this->got_ = new Output_data_got<32, false>();
384 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
385 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
388 // The old GNU linker creates a .got.plt section. We just
389 // create another set of data in the .got section. Note that we
390 // always create a PLT if we create a GOT, although the PLT
392 this->got_plt_ = new Output_data_space(4);
393 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
394 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
397 // The first three entries are reserved.
398 this->got_plt_->set_current_data_size(3 * 4);
400 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
401 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
403 0, 0, elfcpp::STT_OBJECT,
405 elfcpp::STV_HIDDEN, 0,
412 // Get the dynamic reloc section, creating it if necessary.
414 Target_i386::Reloc_section*
415 Target_i386::rel_dyn_section(Layout* layout)
417 if (this->rel_dyn_ == NULL)
419 gold_assert(layout != NULL);
420 this->rel_dyn_ = new Reloc_section();
421 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
422 elfcpp::SHF_ALLOC, this->rel_dyn_);
424 return this->rel_dyn_;
427 // A class to handle the PLT data.
429 class Output_data_plt_i386 : public Output_section_data
432 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
434 Output_data_plt_i386(Layout*, Output_data_space*);
436 // Add an entry to the PLT.
438 add_entry(Symbol* gsym);
440 // Return the .rel.plt section data.
443 { return this->rel_; }
447 do_adjust_output_section(Output_section* os);
450 // The size of an entry in the PLT.
451 static const int plt_entry_size = 16;
453 // The first entry in the PLT for an executable.
454 static unsigned char exec_first_plt_entry[plt_entry_size];
456 // The first entry in the PLT for a shared object.
457 static unsigned char dyn_first_plt_entry[plt_entry_size];
459 // Other entries in the PLT for an executable.
460 static unsigned char exec_plt_entry[plt_entry_size];
462 // Other entries in the PLT for a shared object.
463 static unsigned char dyn_plt_entry[plt_entry_size];
465 // Set the final size.
467 set_final_data_size()
468 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
470 // Write out the PLT data.
472 do_write(Output_file*);
474 // The reloc section.
476 // The .got.plt section.
477 Output_data_space* got_plt_;
478 // The number of PLT entries.
482 // Create the PLT section. The ordinary .got section is an argument,
483 // since we need to refer to the start. We also create our own .got
484 // section just for PLT entries.
486 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
487 Output_data_space* got_plt)
488 : Output_section_data(4), got_plt_(got_plt), count_(0)
490 this->rel_ = new Reloc_section();
491 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
492 elfcpp::SHF_ALLOC, this->rel_);
496 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
498 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
499 // linker, and so do we.
503 // Add an entry to the PLT.
506 Output_data_plt_i386::add_entry(Symbol* gsym)
508 gold_assert(!gsym->has_plt_offset());
510 // Note that when setting the PLT offset we skip the initial
511 // reserved PLT entry.
512 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
516 section_offset_type got_offset = this->got_plt_->current_data_size();
518 // Every PLT entry needs a GOT entry which points back to the PLT
519 // entry (this will be changed by the dynamic linker, normally
520 // lazily when the function is called).
521 this->got_plt_->set_current_data_size(got_offset + 4);
523 // Every PLT entry needs a reloc.
524 gsym->set_needs_dynsym_entry();
525 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
528 // Note that we don't need to save the symbol. The contents of the
529 // PLT are independent of which symbols are used. The symbols only
530 // appear in the relocations.
533 // The first entry in the PLT for an executable.
535 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
537 0xff, 0x35, // pushl contents of memory address
538 0, 0, 0, 0, // replaced with address of .got + 4
539 0xff, 0x25, // jmp indirect
540 0, 0, 0, 0, // replaced with address of .got + 8
544 // The first entry in the PLT for a shared object.
546 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
548 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
549 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
553 // Subsequent entries in the PLT for an executable.
555 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
557 0xff, 0x25, // jmp indirect
558 0, 0, 0, 0, // replaced with address of symbol in .got
559 0x68, // pushl immediate
560 0, 0, 0, 0, // replaced with offset into relocation table
561 0xe9, // jmp relative
562 0, 0, 0, 0 // replaced with offset to start of .plt
565 // Subsequent entries in the PLT for a shared object.
567 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
569 0xff, 0xa3, // jmp *offset(%ebx)
570 0, 0, 0, 0, // replaced with offset of symbol in .got
571 0x68, // pushl immediate
572 0, 0, 0, 0, // replaced with offset into relocation table
573 0xe9, // jmp relative
574 0, 0, 0, 0 // replaced with offset to start of .plt
577 // Write out the PLT. This uses the hand-coded instructions above,
578 // and adjusts them as needed. This is all specified by the i386 ELF
579 // Processor Supplement.
582 Output_data_plt_i386::do_write(Output_file* of)
584 const off_t offset = this->offset();
585 const section_size_type oview_size =
586 convert_to_section_size_type(this->data_size());
587 unsigned char* const oview = of->get_output_view(offset, oview_size);
589 const off_t got_file_offset = this->got_plt_->offset();
590 const section_size_type got_size =
591 convert_to_section_size_type(this->got_plt_->data_size());
592 unsigned char* const got_view = of->get_output_view(got_file_offset,
595 unsigned char* pov = oview;
597 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
598 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
600 if (parameters->output_is_shared())
601 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
604 memcpy(pov, exec_first_plt_entry, plt_entry_size);
605 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
606 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
608 pov += plt_entry_size;
610 unsigned char* got_pov = got_view;
612 memset(got_pov, 0, 12);
615 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
617 unsigned int plt_offset = plt_entry_size;
618 unsigned int plt_rel_offset = 0;
619 unsigned int got_offset = 12;
620 const unsigned int count = this->count_;
621 for (unsigned int i = 0;
624 pov += plt_entry_size,
626 plt_offset += plt_entry_size,
627 plt_rel_offset += rel_size,
630 // Set and adjust the PLT entry itself.
632 if (parameters->output_is_shared())
634 memcpy(pov, dyn_plt_entry, plt_entry_size);
635 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
639 memcpy(pov, exec_plt_entry, plt_entry_size);
640 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
645 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
646 elfcpp::Swap<32, false>::writeval(pov + 12,
647 - (plt_offset + plt_entry_size));
649 // Set the entry in the GOT.
650 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
653 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
654 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
656 of->write_output_view(offset, oview_size, oview);
657 of->write_output_view(got_file_offset, got_size, got_view);
660 // Create a PLT entry for a global symbol.
663 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
665 if (gsym->has_plt_offset())
668 if (this->plt_ == NULL)
670 // Create the GOT sections first.
671 this->got_section(symtab, layout);
673 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
674 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
676 | elfcpp::SHF_EXECINSTR),
680 this->plt_->add_entry(gsym);
683 // Create a GOT entry for the TLS module index.
686 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
687 Sized_relobj<32, false>* object)
689 if (this->got_mod_index_offset_ == -1U)
691 gold_assert(symtab != NULL && layout != NULL && object != NULL);
692 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
693 Output_data_got<32, false>* got = this->got_section(symtab, layout);
694 unsigned int got_offset = got->add_constant(0);
695 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
697 got->add_constant(0);
698 this->got_mod_index_offset_ = got_offset;
700 return this->got_mod_index_offset_;
703 // Handle a relocation against a non-function symbol defined in a
704 // dynamic object. The traditional way to handle this is to generate
705 // a COPY relocation to copy the variable at runtime from the shared
706 // object into the executable's data segment. However, this is
707 // undesirable in general, as if the size of the object changes in the
708 // dynamic object, the executable will no longer work correctly. If
709 // this relocation is in a writable section, then we can create a
710 // dynamic reloc and the dynamic linker will resolve it to the correct
711 // address at runtime. However, we do not want do that if the
712 // relocation is in a read-only section, as it would prevent the
713 // readonly segment from being shared. And if we have to eventually
714 // generate a COPY reloc, then any dynamic relocations will be
715 // useless. So this means that if this is a writable section, we need
716 // to save the relocation until we see whether we have to create a
717 // COPY relocation for this symbol for any other relocation.
720 Target_i386::copy_reloc(const General_options* options,
721 Symbol_table* symtab,
723 Sized_relobj<32, false>* object,
724 unsigned int data_shndx,
725 Output_section* output_section,
727 const elfcpp::Rel<32, false>& rel)
729 Sized_symbol<32>* ssym;
730 ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
733 if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
736 // So far we do not need a COPY reloc. Save this relocation.
737 // If it turns out that we never need a COPY reloc for this
738 // symbol, then we will emit the relocation.
739 if (this->copy_relocs_ == NULL)
740 this->copy_relocs_ = new Copy_relocs<32, false>();
741 this->copy_relocs_->save(ssym, object, data_shndx, output_section, rel);
745 // Allocate space for this symbol in the .bss section.
747 elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
749 // There is no defined way to determine the required alignment
750 // of the symbol. We pick the alignment based on the size. We
751 // set an arbitrary maximum of 256.
753 for (align = 1; align < 512; align <<= 1)
754 if ((symsize & align) != 0)
757 if (this->dynbss_ == NULL)
759 this->dynbss_ = new Output_data_space(align);
760 layout->add_output_section_data(".bss",
763 | elfcpp::SHF_WRITE),
767 Output_data_space* dynbss = this->dynbss_;
769 if (align > dynbss->addralign())
770 dynbss->set_space_alignment(align);
772 section_size_type dynbss_size =
773 convert_to_section_size_type(dynbss->current_data_size());
774 dynbss_size = align_address(dynbss_size, align);
775 section_size_type offset = dynbss_size;
776 dynbss->set_current_data_size(dynbss_size + symsize);
778 symtab->define_with_copy_reloc(ssym, dynbss, offset);
780 // Add the COPY reloc.
781 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
782 rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
786 // Optimize the TLS relocation type based on what we know about the
787 // symbol. IS_FINAL is true if the final address of this symbol is
788 // known at link time.
790 tls::Tls_optimization
791 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
793 // If we are generating a shared library, then we can't do anything
795 if (parameters->output_is_shared())
796 return tls::TLSOPT_NONE;
800 case elfcpp::R_386_TLS_GD:
801 case elfcpp::R_386_TLS_GOTDESC:
802 case elfcpp::R_386_TLS_DESC_CALL:
803 // These are General-Dynamic which permits fully general TLS
804 // access. Since we know that we are generating an executable,
805 // we can convert this to Initial-Exec. If we also know that
806 // this is a local symbol, we can further switch to Local-Exec.
808 return tls::TLSOPT_TO_LE;
809 return tls::TLSOPT_TO_IE;
811 case elfcpp::R_386_TLS_LDM:
812 // This is Local-Dynamic, which refers to a local symbol in the
813 // dynamic TLS block. Since we know that we generating an
814 // executable, we can switch to Local-Exec.
815 return tls::TLSOPT_TO_LE;
817 case elfcpp::R_386_TLS_LDO_32:
818 // Another type of Local-Dynamic relocation.
819 return tls::TLSOPT_TO_LE;
821 case elfcpp::R_386_TLS_IE:
822 case elfcpp::R_386_TLS_GOTIE:
823 case elfcpp::R_386_TLS_IE_32:
824 // These are Initial-Exec relocs which get the thread offset
825 // from the GOT. If we know that we are linking against the
826 // local symbol, we can switch to Local-Exec, which links the
827 // thread offset into the instruction.
829 return tls::TLSOPT_TO_LE;
830 return tls::TLSOPT_NONE;
832 case elfcpp::R_386_TLS_LE:
833 case elfcpp::R_386_TLS_LE_32:
834 // When we already have Local-Exec, there is nothing further we
836 return tls::TLSOPT_NONE;
843 // Report an unsupported relocation against a local symbol.
846 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
849 gold_error(_("%s: unsupported reloc %u against local symbol"),
850 object->name().c_str(), r_type);
853 // Scan a relocation for a local symbol.
856 Target_i386::Scan::local(const General_options&,
857 Symbol_table* symtab,
860 Sized_relobj<32, false>* object,
861 unsigned int data_shndx,
862 Output_section* output_section,
863 const elfcpp::Rel<32, false>& reloc,
865 const elfcpp::Sym<32, false>& lsym)
869 case elfcpp::R_386_NONE:
870 case elfcpp::R_386_GNU_VTINHERIT:
871 case elfcpp::R_386_GNU_VTENTRY:
874 case elfcpp::R_386_32:
875 // If building a shared library (or a position-independent
876 // executable), we need to create a dynamic relocation for
877 // this location. The relocation applied at link time will
878 // apply the link-time value, so we flag the location with
879 // an R_386_RELATIVE relocation so the dynamic loader can
880 // relocate it easily.
881 if (parameters->output_is_position_independent())
883 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
884 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
885 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
886 output_section, data_shndx,
887 reloc.get_r_offset());
891 case elfcpp::R_386_16:
892 case elfcpp::R_386_8:
893 // If building a shared library (or a position-independent
894 // executable), we need to create a dynamic relocation for
895 // this location. Because the addend needs to remain in the
896 // data section, we need to be careful not to apply this
897 // relocation statically.
898 if (parameters->output_is_position_independent())
900 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
901 if (lsym.get_st_type() != elfcpp::STT_SECTION)
903 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
904 rel_dyn->add_local(object, r_sym, r_type, output_section,
905 data_shndx, reloc.get_r_offset());
909 gold_assert(lsym.get_st_value() == 0);
910 rel_dyn->add_local_section(object, lsym.get_st_shndx(),
911 r_type, output_section,
912 data_shndx, reloc.get_r_offset());
917 case elfcpp::R_386_PC32:
918 case elfcpp::R_386_PC16:
919 case elfcpp::R_386_PC8:
922 case elfcpp::R_386_PLT32:
923 // Since we know this is a local symbol, we can handle this as a
927 case elfcpp::R_386_GOTOFF:
928 case elfcpp::R_386_GOTPC:
929 // We need a GOT section.
930 target->got_section(symtab, layout);
933 case elfcpp::R_386_GOT32:
935 // The symbol requires a GOT entry.
936 Output_data_got<32, false>* got = target->got_section(symtab, layout);
937 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
938 if (got->add_local(object, r_sym))
940 // If we are generating a shared object, we need to add a
941 // dynamic RELATIVE relocation for this symbol's GOT entry.
942 if (parameters->output_is_position_independent())
944 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
945 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
946 rel_dyn->add_local_relative(object, r_sym,
947 elfcpp::R_386_RELATIVE,
949 object->local_got_offset(r_sym));
955 // These are relocations which should only be seen by the
956 // dynamic linker, and should never be seen here.
957 case elfcpp::R_386_COPY:
958 case elfcpp::R_386_GLOB_DAT:
959 case elfcpp::R_386_JUMP_SLOT:
960 case elfcpp::R_386_RELATIVE:
961 case elfcpp::R_386_TLS_TPOFF:
962 case elfcpp::R_386_TLS_DTPMOD32:
963 case elfcpp::R_386_TLS_DTPOFF32:
964 case elfcpp::R_386_TLS_TPOFF32:
965 case elfcpp::R_386_TLS_DESC:
966 gold_error(_("%s: unexpected reloc %u in object file"),
967 object->name().c_str(), r_type);
970 // These are initial TLS relocs, which are expected when
972 case elfcpp::R_386_TLS_GD: // Global-dynamic
973 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
974 case elfcpp::R_386_TLS_DESC_CALL:
975 case elfcpp::R_386_TLS_LDM: // Local-dynamic
976 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
977 case elfcpp::R_386_TLS_IE: // Initial-exec
978 case elfcpp::R_386_TLS_IE_32:
979 case elfcpp::R_386_TLS_GOTIE:
980 case elfcpp::R_386_TLS_LE: // Local-exec
981 case elfcpp::R_386_TLS_LE_32:
983 bool output_is_shared = parameters->output_is_shared();
984 const tls::Tls_optimization optimized_type
985 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
988 case elfcpp::R_386_TLS_GD: // Global-dynamic
989 if (optimized_type == tls::TLSOPT_NONE)
991 // Create a pair of GOT entries for the module index and
992 // dtv-relative offset.
993 Output_data_got<32, false>* got
994 = target->got_section(symtab, layout);
995 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
996 got->add_local_tls_with_rel(object, r_sym,
997 lsym.get_st_shndx(), true,
998 target->rel_dyn_section(layout),
999 elfcpp::R_386_TLS_DTPMOD32);
1001 else if (optimized_type != tls::TLSOPT_TO_LE)
1002 unsupported_reloc_local(object, r_type);
1005 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1006 case elfcpp::R_386_TLS_DESC_CALL:
1007 // FIXME: If not relaxing to LE, we need to generate
1008 // a GOT entry with an R_386_TLS_DESC reloc.
1009 if (optimized_type != tls::TLSOPT_TO_LE)
1010 unsupported_reloc_local(object, r_type);
1013 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1014 if (optimized_type == tls::TLSOPT_NONE)
1016 // Create a GOT entry for the module index.
1017 target->got_mod_index_entry(symtab, layout, object);
1019 else if (optimized_type != tls::TLSOPT_TO_LE)
1020 unsupported_reloc_local(object, r_type);
1023 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1026 case elfcpp::R_386_TLS_IE: // Initial-exec
1027 case elfcpp::R_386_TLS_IE_32:
1028 case elfcpp::R_386_TLS_GOTIE:
1029 layout->set_has_static_tls();
1030 if (optimized_type == tls::TLSOPT_NONE)
1032 // For the R_386_TLS_IE relocation, we need to create a
1033 // dynamic relocation when building a shared library.
1034 if (r_type == elfcpp::R_386_TLS_IE
1035 && parameters->output_is_shared())
1037 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1039 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1040 rel_dyn->add_local_relative(object, r_sym,
1041 elfcpp::R_386_RELATIVE,
1042 output_section, data_shndx,
1043 reloc.get_r_offset());
1045 // Create a GOT entry for the tp-relative offset.
1046 Output_data_got<32, false>* got
1047 = target->got_section(symtab, layout);
1048 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1049 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1050 ? elfcpp::R_386_TLS_TPOFF32
1051 : elfcpp::R_386_TLS_TPOFF);
1052 got->add_local_with_rel(object, r_sym,
1053 target->rel_dyn_section(layout),
1056 else if (optimized_type != tls::TLSOPT_TO_LE)
1057 unsupported_reloc_local(object, r_type);
1060 case elfcpp::R_386_TLS_LE: // Local-exec
1061 case elfcpp::R_386_TLS_LE_32:
1062 layout->set_has_static_tls();
1063 if (output_is_shared)
1065 // We need to create a dynamic relocation.
1066 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1067 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1068 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1069 ? elfcpp::R_386_TLS_TPOFF32
1070 : elfcpp::R_386_TLS_TPOFF);
1071 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1072 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1073 data_shndx, reloc.get_r_offset());
1083 case elfcpp::R_386_32PLT:
1084 case elfcpp::R_386_TLS_GD_32:
1085 case elfcpp::R_386_TLS_GD_PUSH:
1086 case elfcpp::R_386_TLS_GD_CALL:
1087 case elfcpp::R_386_TLS_GD_POP:
1088 case elfcpp::R_386_TLS_LDM_32:
1089 case elfcpp::R_386_TLS_LDM_PUSH:
1090 case elfcpp::R_386_TLS_LDM_CALL:
1091 case elfcpp::R_386_TLS_LDM_POP:
1092 case elfcpp::R_386_USED_BY_INTEL_200:
1094 unsupported_reloc_local(object, r_type);
1099 // Report an unsupported relocation against a global symbol.
1102 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1103 unsigned int r_type,
1106 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1107 object->name().c_str(), r_type, gsym->demangled_name().c_str());
1110 // Scan a relocation for a global symbol.
1113 Target_i386::Scan::global(const General_options& options,
1114 Symbol_table* symtab,
1116 Target_i386* target,
1117 Sized_relobj<32, false>* object,
1118 unsigned int data_shndx,
1119 Output_section* output_section,
1120 const elfcpp::Rel<32, false>& reloc,
1121 unsigned int r_type,
1126 case elfcpp::R_386_NONE:
1127 case elfcpp::R_386_GNU_VTINHERIT:
1128 case elfcpp::R_386_GNU_VTENTRY:
1131 case elfcpp::R_386_32:
1132 case elfcpp::R_386_16:
1133 case elfcpp::R_386_8:
1135 // Make a PLT entry if necessary.
1136 if (gsym->needs_plt_entry())
1138 target->make_plt_entry(symtab, layout, gsym);
1139 // Since this is not a PC-relative relocation, we may be
1140 // taking the address of a function. In that case we need to
1141 // set the entry in the dynamic symbol table to the address of
1143 if (gsym->is_from_dynobj() && !parameters->output_is_shared())
1144 gsym->set_needs_dynsym_value();
1146 // Make a dynamic relocation if necessary.
1147 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1149 if (target->may_need_copy_reloc(gsym))
1151 target->copy_reloc(&options, symtab, layout, object,
1152 data_shndx, output_section, gsym, reloc);
1154 else if (r_type == elfcpp::R_386_32
1155 && gsym->can_use_relative_reloc(false))
1157 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1158 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1159 output_section, object,
1160 data_shndx, reloc.get_r_offset());
1164 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1165 rel_dyn->add_global(gsym, r_type, output_section, object,
1166 data_shndx, reloc.get_r_offset());
1172 case elfcpp::R_386_PC32:
1173 case elfcpp::R_386_PC16:
1174 case elfcpp::R_386_PC8:
1176 // Make a PLT entry if necessary.
1177 if (gsym->needs_plt_entry())
1179 // These relocations are used for function calls only in
1180 // non-PIC code. For a 32-bit relocation in a shared library,
1181 // we'll need a text relocation anyway, so we can skip the
1182 // PLT entry and let the dynamic linker bind the call directly
1183 // to the target. For smaller relocations, we should use a
1184 // PLT entry to ensure that the call can reach.
1185 if (!parameters->output_is_shared()
1186 || r_type != elfcpp::R_386_PC32)
1187 target->make_plt_entry(symtab, layout, gsym);
1189 // Make a dynamic relocation if necessary.
1190 int flags = Symbol::NON_PIC_REF;
1191 if (gsym->type() == elfcpp::STT_FUNC)
1192 flags |= Symbol::FUNCTION_CALL;
1193 if (gsym->needs_dynamic_reloc(flags))
1195 if (target->may_need_copy_reloc(gsym))
1197 target->copy_reloc(&options, symtab, layout, object,
1198 data_shndx, output_section, gsym, reloc);
1202 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1203 rel_dyn->add_global(gsym, r_type, output_section, object,
1204 data_shndx, reloc.get_r_offset());
1210 case elfcpp::R_386_GOT32:
1212 // The symbol requires a GOT entry.
1213 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1214 if (gsym->final_value_is_known())
1215 got->add_global(gsym);
1218 // If this symbol is not fully resolved, we need to add a
1219 // GOT entry with a dynamic relocation.
1220 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1221 if (gsym->is_from_dynobj()
1222 || gsym->is_undefined()
1223 || gsym->is_preemptible())
1224 got->add_global_with_rel(gsym, rel_dyn, elfcpp::R_386_GLOB_DAT);
1227 if (got->add_global(gsym))
1228 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1229 got, gsym->got_offset());
1235 case elfcpp::R_386_PLT32:
1236 // If the symbol is fully resolved, this is just a PC32 reloc.
1237 // Otherwise we need a PLT entry.
1238 if (gsym->final_value_is_known())
1240 // If building a shared library, we can also skip the PLT entry
1241 // if the symbol is defined in the output file and is protected
1243 if (gsym->is_defined()
1244 && !gsym->is_from_dynobj()
1245 && !gsym->is_preemptible())
1247 target->make_plt_entry(symtab, layout, gsym);
1250 case elfcpp::R_386_GOTOFF:
1251 case elfcpp::R_386_GOTPC:
1252 // We need a GOT section.
1253 target->got_section(symtab, layout);
1256 // These are relocations which should only be seen by the
1257 // dynamic linker, and should never be seen here.
1258 case elfcpp::R_386_COPY:
1259 case elfcpp::R_386_GLOB_DAT:
1260 case elfcpp::R_386_JUMP_SLOT:
1261 case elfcpp::R_386_RELATIVE:
1262 case elfcpp::R_386_TLS_TPOFF:
1263 case elfcpp::R_386_TLS_DTPMOD32:
1264 case elfcpp::R_386_TLS_DTPOFF32:
1265 case elfcpp::R_386_TLS_TPOFF32:
1266 case elfcpp::R_386_TLS_DESC:
1267 gold_error(_("%s: unexpected reloc %u in object file"),
1268 object->name().c_str(), r_type);
1271 // These are initial tls relocs, which are expected when
1273 case elfcpp::R_386_TLS_GD: // Global-dynamic
1274 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1275 case elfcpp::R_386_TLS_DESC_CALL:
1276 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1277 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1278 case elfcpp::R_386_TLS_IE: // Initial-exec
1279 case elfcpp::R_386_TLS_IE_32:
1280 case elfcpp::R_386_TLS_GOTIE:
1281 case elfcpp::R_386_TLS_LE: // Local-exec
1282 case elfcpp::R_386_TLS_LE_32:
1284 const bool is_final = gsym->final_value_is_known();
1285 const tls::Tls_optimization optimized_type
1286 = Target_i386::optimize_tls_reloc(is_final, r_type);
1289 case elfcpp::R_386_TLS_GD: // Global-dynamic
1290 if (optimized_type == tls::TLSOPT_NONE)
1292 // Create a pair of GOT entries for the module index and
1293 // dtv-relative offset.
1294 Output_data_got<32, false>* got
1295 = target->got_section(symtab, layout);
1296 got->add_global_tls_with_rel(gsym,
1297 target->rel_dyn_section(layout),
1298 elfcpp::R_386_TLS_DTPMOD32,
1299 elfcpp::R_386_TLS_DTPOFF32);
1301 else if (optimized_type == tls::TLSOPT_TO_IE)
1303 // Create a GOT entry for the tp-relative offset.
1304 Output_data_got<32, false>* got
1305 = target->got_section(symtab, layout);
1306 got->add_global_with_rel(gsym, target->rel_dyn_section(layout),
1307 elfcpp::R_386_TLS_TPOFF32);
1309 else if (optimized_type != tls::TLSOPT_TO_LE)
1310 unsupported_reloc_global(object, r_type, gsym);
1313 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
1314 case elfcpp::R_386_TLS_DESC_CALL:
1315 // FIXME: If not relaxing to LE, we need to generate
1316 // a GOT entry with an R_386_TLS_DESC reloc.
1317 if (optimized_type != tls::TLSOPT_TO_LE)
1318 unsupported_reloc_global(object, r_type, gsym);
1319 unsupported_reloc_global(object, r_type, gsym);
1322 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1323 if (optimized_type == tls::TLSOPT_NONE)
1325 // Create a GOT entry for the module index.
1326 target->got_mod_index_entry(symtab, layout, object);
1328 else if (optimized_type != tls::TLSOPT_TO_LE)
1329 unsupported_reloc_global(object, r_type, gsym);
1332 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1335 case elfcpp::R_386_TLS_IE: // Initial-exec
1336 case elfcpp::R_386_TLS_IE_32:
1337 case elfcpp::R_386_TLS_GOTIE:
1338 layout->set_has_static_tls();
1339 if (optimized_type == tls::TLSOPT_NONE)
1341 // For the R_386_TLS_IE relocation, we need to create a
1342 // dynamic relocation when building a shared library.
1343 if (r_type == elfcpp::R_386_TLS_IE
1344 && parameters->output_is_shared())
1346 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1347 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1348 output_section, object,
1350 reloc.get_r_offset());
1352 // Create a GOT entry for the tp-relative offset.
1353 Output_data_got<32, false>* got
1354 = target->got_section(symtab, layout);
1355 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1356 ? elfcpp::R_386_TLS_TPOFF32
1357 : elfcpp::R_386_TLS_TPOFF);
1358 got->add_global_with_rel(gsym,
1359 target->rel_dyn_section(layout),
1362 else if (optimized_type != tls::TLSOPT_TO_LE)
1363 unsupported_reloc_global(object, r_type, gsym);
1366 case elfcpp::R_386_TLS_LE: // Local-exec
1367 case elfcpp::R_386_TLS_LE_32:
1368 layout->set_has_static_tls();
1369 if (parameters->output_is_shared())
1371 // We need to create a dynamic relocation.
1372 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1373 ? elfcpp::R_386_TLS_TPOFF32
1374 : elfcpp::R_386_TLS_TPOFF);
1375 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1376 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1377 data_shndx, reloc.get_r_offset());
1387 case elfcpp::R_386_32PLT:
1388 case elfcpp::R_386_TLS_GD_32:
1389 case elfcpp::R_386_TLS_GD_PUSH:
1390 case elfcpp::R_386_TLS_GD_CALL:
1391 case elfcpp::R_386_TLS_GD_POP:
1392 case elfcpp::R_386_TLS_LDM_32:
1393 case elfcpp::R_386_TLS_LDM_PUSH:
1394 case elfcpp::R_386_TLS_LDM_CALL:
1395 case elfcpp::R_386_TLS_LDM_POP:
1396 case elfcpp::R_386_USED_BY_INTEL_200:
1398 unsupported_reloc_global(object, r_type, gsym);
1403 // Scan relocations for a section.
1406 Target_i386::scan_relocs(const General_options& options,
1407 Symbol_table* symtab,
1409 Sized_relobj<32, false>* object,
1410 unsigned int data_shndx,
1411 unsigned int sh_type,
1412 const unsigned char* prelocs,
1414 Output_section* output_section,
1415 bool needs_special_offset_handling,
1416 size_t local_symbol_count,
1417 const unsigned char* plocal_symbols)
1419 if (sh_type == elfcpp::SHT_RELA)
1421 gold_error(_("%s: unsupported RELA reloc section"),
1422 object->name().c_str());
1426 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1437 needs_special_offset_handling,
1442 // Finalize the sections.
1445 Target_i386::do_finalize_sections(Layout* layout)
1447 // Fill in some more dynamic tags.
1448 Output_data_dynamic* const odyn = layout->dynamic_data();
1451 if (this->got_plt_ != NULL)
1452 odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1454 if (this->plt_ != NULL)
1456 const Output_data* od = this->plt_->rel_plt();
1457 odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1458 odyn->add_section_address(elfcpp::DT_JMPREL, od);
1459 odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1462 if (this->rel_dyn_ != NULL)
1464 const Output_data* od = this->rel_dyn_;
1465 odyn->add_section_address(elfcpp::DT_REL, od);
1466 odyn->add_section_size(elfcpp::DT_RELSZ, od);
1467 odyn->add_constant(elfcpp::DT_RELENT,
1468 elfcpp::Elf_sizes<32>::rel_size);
1471 if (!parameters->output_is_shared())
1473 // The value of the DT_DEBUG tag is filled in by the dynamic
1474 // linker at run time, and used by the debugger.
1475 odyn->add_constant(elfcpp::DT_DEBUG, 0);
1479 // Emit any relocs we saved in an attempt to avoid generating COPY
1481 if (this->copy_relocs_ == NULL)
1483 if (this->copy_relocs_->any_to_emit())
1485 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1486 this->copy_relocs_->emit(rel_dyn);
1488 delete this->copy_relocs_;
1489 this->copy_relocs_ = NULL;
1492 // Return whether a direct absolute static relocation needs to be applied.
1493 // In cases where Scan::local() or Scan::global() has created
1494 // a dynamic relocation other than R_386_RELATIVE, the addend
1495 // of the relocation is carried in the data, and we must not
1496 // apply the static relocation.
1499 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1503 // For local symbols, we will have created a non-RELATIVE dynamic
1504 // relocation only if (a) the output is position independent,
1505 // (b) the relocation is absolute (not pc- or segment-relative), and
1506 // (c) the relocation is not 32 bits wide.
1508 return !(parameters->output_is_position_independent()
1509 && (ref_flags & Symbol::ABSOLUTE_REF)
1512 // For global symbols, we use the same helper routines used in the
1513 // scan pass. If we did not create a dynamic relocation, or if we
1514 // created a RELATIVE dynamic relocation, we should apply the static
1516 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1517 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1518 && gsym->can_use_relative_reloc(ref_flags
1519 & Symbol::FUNCTION_CALL);
1520 return !has_dyn || is_rel;
1523 // Perform a relocation.
1526 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1527 Target_i386* target,
1529 const elfcpp::Rel<32, false>& rel,
1530 unsigned int r_type,
1531 const Sized_symbol<32>* gsym,
1532 const Symbol_value<32>* psymval,
1533 unsigned char* view,
1534 elfcpp::Elf_types<32>::Elf_Addr address,
1535 section_size_type view_size)
1537 if (this->skip_call_tls_get_addr_)
1539 if (r_type != elfcpp::R_386_PLT32
1541 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1542 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1543 _("missing expected TLS relocation"));
1546 this->skip_call_tls_get_addr_ = false;
1551 // Pick the value to use for symbols defined in shared objects.
1552 Symbol_value<32> symval;
1553 bool is_nonpic = (r_type == elfcpp::R_386_PC8
1554 || r_type == elfcpp::R_386_PC16
1555 || r_type == elfcpp::R_386_PC32);
1557 && (gsym->is_from_dynobj()
1558 || (parameters->output_is_shared()
1559 && (gsym->is_undefined() || gsym->is_preemptible())))
1560 && gsym->has_plt_offset()
1561 && (!is_nonpic || !parameters->output_is_shared()))
1563 symval.set_output_value(target->plt_section()->address()
1564 + gsym->plt_offset());
1568 const Sized_relobj<32, false>* object = relinfo->object;
1570 // Get the GOT offset if needed.
1571 // The GOT pointer points to the end of the GOT section.
1572 // We need to subtract the size of the GOT section to get
1573 // the actual offset to use in the relocation.
1574 bool have_got_offset = false;
1575 unsigned int got_offset = 0;
1578 case elfcpp::R_386_GOT32:
1581 gold_assert(gsym->has_got_offset());
1582 got_offset = gsym->got_offset() - target->got_size();
1586 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1587 gold_assert(object->local_has_got_offset(r_sym));
1588 got_offset = object->local_got_offset(r_sym) - target->got_size();
1590 have_got_offset = true;
1599 case elfcpp::R_386_NONE:
1600 case elfcpp::R_386_GNU_VTINHERIT:
1601 case elfcpp::R_386_GNU_VTENTRY:
1604 case elfcpp::R_386_32:
1605 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true))
1606 Relocate_functions<32, false>::rel32(view, object, psymval);
1609 case elfcpp::R_386_PC32:
1611 int ref_flags = Symbol::NON_PIC_REF;
1612 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1613 ref_flags |= Symbol::FUNCTION_CALL;
1614 if (should_apply_static_reloc(gsym, ref_flags, true))
1615 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1619 case elfcpp::R_386_16:
1620 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
1621 Relocate_functions<32, false>::rel16(view, object, psymval);
1624 case elfcpp::R_386_PC16:
1626 int ref_flags = Symbol::NON_PIC_REF;
1627 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1628 ref_flags |= Symbol::FUNCTION_CALL;
1629 if (should_apply_static_reloc(gsym, ref_flags, false))
1630 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1634 case elfcpp::R_386_8:
1635 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
1636 Relocate_functions<32, false>::rel8(view, object, psymval);
1639 case elfcpp::R_386_PC8:
1641 int ref_flags = Symbol::NON_PIC_REF;
1642 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1643 ref_flags |= Symbol::FUNCTION_CALL;
1644 if (should_apply_static_reloc(gsym, ref_flags, false))
1645 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1649 case elfcpp::R_386_PLT32:
1650 gold_assert(gsym == NULL
1651 || gsym->has_plt_offset()
1652 || gsym->final_value_is_known()
1653 || (gsym->is_defined()
1654 && !gsym->is_from_dynobj()
1655 && !gsym->is_preemptible()));
1656 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1659 case elfcpp::R_386_GOT32:
1660 gold_assert(have_got_offset);
1661 Relocate_functions<32, false>::rel32(view, got_offset);
1664 case elfcpp::R_386_GOTOFF:
1666 elfcpp::Elf_types<32>::Elf_Addr value;
1667 value = (psymval->value(object, 0)
1668 - target->got_plt_section()->address());
1669 Relocate_functions<32, false>::rel32(view, value);
1673 case elfcpp::R_386_GOTPC:
1675 elfcpp::Elf_types<32>::Elf_Addr value;
1676 value = target->got_plt_section()->address();
1677 Relocate_functions<32, false>::pcrel32(view, value, address);
1681 case elfcpp::R_386_COPY:
1682 case elfcpp::R_386_GLOB_DAT:
1683 case elfcpp::R_386_JUMP_SLOT:
1684 case elfcpp::R_386_RELATIVE:
1685 // These are outstanding tls relocs, which are unexpected when
1687 case elfcpp::R_386_TLS_TPOFF:
1688 case elfcpp::R_386_TLS_DTPMOD32:
1689 case elfcpp::R_386_TLS_DTPOFF32:
1690 case elfcpp::R_386_TLS_TPOFF32:
1691 case elfcpp::R_386_TLS_DESC:
1692 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1693 _("unexpected reloc %u in object file"),
1697 // These are initial tls relocs, which are expected when
1699 case elfcpp::R_386_TLS_GD: // Global-dynamic
1700 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1701 case elfcpp::R_386_TLS_DESC_CALL:
1702 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1703 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1704 case elfcpp::R_386_TLS_IE: // Initial-exec
1705 case elfcpp::R_386_TLS_IE_32:
1706 case elfcpp::R_386_TLS_GOTIE:
1707 case elfcpp::R_386_TLS_LE: // Local-exec
1708 case elfcpp::R_386_TLS_LE_32:
1709 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1710 view, address, view_size);
1713 case elfcpp::R_386_32PLT:
1714 case elfcpp::R_386_TLS_GD_32:
1715 case elfcpp::R_386_TLS_GD_PUSH:
1716 case elfcpp::R_386_TLS_GD_CALL:
1717 case elfcpp::R_386_TLS_GD_POP:
1718 case elfcpp::R_386_TLS_LDM_32:
1719 case elfcpp::R_386_TLS_LDM_PUSH:
1720 case elfcpp::R_386_TLS_LDM_CALL:
1721 case elfcpp::R_386_TLS_LDM_POP:
1722 case elfcpp::R_386_USED_BY_INTEL_200:
1724 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1725 _("unsupported reloc %u"),
1733 // Perform a TLS relocation.
1736 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1737 Target_i386* target,
1739 const elfcpp::Rel<32, false>& rel,
1740 unsigned int r_type,
1741 const Sized_symbol<32>* gsym,
1742 const Symbol_value<32>* psymval,
1743 unsigned char* view,
1744 elfcpp::Elf_types<32>::Elf_Addr,
1745 section_size_type view_size)
1747 Output_segment* tls_segment = relinfo->layout->tls_segment();
1749 const Sized_relobj<32, false>* object = relinfo->object;
1751 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1753 const bool is_final = (gsym == NULL
1754 ? !parameters->output_is_position_independent()
1755 : gsym->final_value_is_known());
1756 const tls::Tls_optimization optimized_type
1757 = Target_i386::optimize_tls_reloc(is_final, r_type);
1760 case elfcpp::R_386_TLS_GD: // Global-dynamic
1761 if (optimized_type == tls::TLSOPT_TO_LE)
1763 gold_assert(tls_segment != NULL);
1764 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1765 rel, r_type, value, view,
1771 unsigned int got_offset;
1774 gold_assert(gsym->has_tls_got_offset(true));
1775 got_offset = gsym->tls_got_offset(true) - target->got_size();
1779 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1780 gold_assert(object->local_has_tls_got_offset(r_sym, true));
1781 got_offset = (object->local_tls_got_offset(r_sym, true)
1782 - target->got_size());
1784 if (optimized_type == tls::TLSOPT_TO_IE)
1786 gold_assert(tls_segment != NULL);
1787 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1788 got_offset, view, view_size);
1791 else if (optimized_type == tls::TLSOPT_NONE)
1793 // Relocate the field with the offset of the pair of GOT
1795 Relocate_functions<32, false>::rel32(view, got_offset);
1799 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1800 _("unsupported reloc %u"),
1804 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1805 case elfcpp::R_386_TLS_DESC_CALL:
1806 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1807 _("unsupported reloc %u"),
1811 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1812 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1814 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1815 _("both SUN and GNU model "
1816 "TLS relocations"));
1819 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1820 if (optimized_type == tls::TLSOPT_TO_LE)
1822 gold_assert(tls_segment != NULL);
1823 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1824 value, view, view_size);
1827 else if (optimized_type == tls::TLSOPT_NONE)
1829 // Relocate the field with the offset of the GOT entry for
1830 // the module index.
1831 unsigned int got_offset;
1832 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
1833 - target->got_size());
1834 Relocate_functions<32, false>::rel32(view, got_offset);
1837 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1838 _("unsupported reloc %u"),
1842 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1843 // This reloc can appear in debugging sections, in which case we
1844 // won't see the TLS_LDM reloc. The local_dynamic_type field
1846 if (optimized_type == tls::TLSOPT_TO_LE)
1848 gold_assert(tls_segment != NULL);
1849 value -= tls_segment->memsz();
1851 Relocate_functions<32, false>::rel32(view, value);
1854 case elfcpp::R_386_TLS_IE: // Initial-exec
1855 case elfcpp::R_386_TLS_GOTIE:
1856 case elfcpp::R_386_TLS_IE_32:
1857 if (optimized_type == tls::TLSOPT_TO_LE)
1859 gold_assert(tls_segment != NULL);
1860 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1861 rel, r_type, value, view,
1865 else if (optimized_type == tls::TLSOPT_NONE)
1867 // Relocate the field with the offset of the GOT entry for
1868 // the tp-relative offset of the symbol.
1869 unsigned int got_offset;
1872 gold_assert(gsym->has_got_offset());
1873 got_offset = gsym->got_offset();
1877 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1878 gold_assert(object->local_has_got_offset(r_sym));
1879 got_offset = object->local_got_offset(r_sym);
1881 // For the R_386_TLS_IE relocation, we need to apply the
1882 // absolute address of the GOT entry.
1883 if (r_type == elfcpp::R_386_TLS_IE)
1884 got_offset += target->got_plt_section()->address();
1885 // All GOT offsets are relative to the end of the GOT.
1886 got_offset -= target->got_size();
1887 Relocate_functions<32, false>::rel32(view, got_offset);
1890 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1891 _("unsupported reloc %u"),
1895 case elfcpp::R_386_TLS_LE: // Local-exec
1896 // If we're creating a shared library, a dynamic relocation will
1897 // have been created for this location, so do not apply it now.
1898 if (!parameters->output_is_shared())
1900 gold_assert(tls_segment != NULL);
1901 value -= tls_segment->memsz();
1902 Relocate_functions<32, false>::rel32(view, value);
1906 case elfcpp::R_386_TLS_LE_32:
1907 // If we're creating a shared library, a dynamic relocation will
1908 // have been created for this location, so do not apply it now.
1909 if (!parameters->output_is_shared())
1911 gold_assert(tls_segment != NULL);
1912 value = tls_segment->memsz() - value;
1913 Relocate_functions<32, false>::rel32(view, value);
1919 // Do a relocation in which we convert a TLS General-Dynamic to a
1923 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1925 Output_segment* tls_segment,
1926 const elfcpp::Rel<32, false>& rel,
1928 elfcpp::Elf_types<32>::Elf_Addr value,
1929 unsigned char* view,
1930 section_size_type view_size)
1932 // leal foo(,%reg,1),%eax; call ___tls_get_addr
1933 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1934 // leal foo(%reg),%eax; call ___tls_get_addr
1935 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1937 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1938 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1940 unsigned char op1 = view[-1];
1941 unsigned char op2 = view[-2];
1943 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1944 op2 == 0x8d || op2 == 0x04);
1945 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1951 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
1952 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
1953 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1954 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
1955 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1959 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1960 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1961 if (rel.get_r_offset() + 9 < view_size
1964 // There is a trailing nop. Use the size byte subl.
1965 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1970 // Use the five byte subl.
1971 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1975 value = tls_segment->memsz() - value;
1976 Relocate_functions<32, false>::rel32(view + roff, value);
1978 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1980 this->skip_call_tls_get_addr_ = true;
1983 // Do a relocation in which we convert a TLS General-Dynamic to an
1987 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
1989 Output_segment* tls_segment,
1990 const elfcpp::Rel<32, false>& rel,
1992 elfcpp::Elf_types<32>::Elf_Addr value,
1993 unsigned char* view,
1994 section_size_type view_size)
1996 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
1997 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
1999 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2000 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2002 unsigned char op1 = view[-1];
2003 unsigned char op2 = view[-2];
2005 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2006 op2 == 0x8d || op2 == 0x04);
2007 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2011 // FIXME: For now, support only one form.
2012 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2013 op1 == 0x8d && op2 == 0x04);
2017 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2018 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2019 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2020 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2021 memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2025 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2026 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2027 if (rel.get_r_offset() + 9 < view_size
2030 // FIXME: This is not the right instruction sequence.
2031 // There is a trailing nop. Use the size byte subl.
2032 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2037 // FIXME: This is not the right instruction sequence.
2038 // Use the five byte subl.
2039 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2043 value = tls_segment->memsz() - value;
2044 Relocate_functions<32, false>::rel32(view + roff, value);
2046 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2048 this->skip_call_tls_get_addr_ = true;
2051 // Do a relocation in which we convert a TLS Local-Dynamic to a
2055 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2058 const elfcpp::Rel<32, false>& rel,
2060 elfcpp::Elf_types<32>::Elf_Addr,
2061 unsigned char* view,
2062 section_size_type view_size)
2064 // leal foo(%reg), %eax; call ___tls_get_addr
2065 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2067 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2068 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2070 // FIXME: Does this test really always pass?
2071 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2072 view[-2] == 0x8d && view[-1] == 0x83);
2074 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2076 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2078 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2080 this->skip_call_tls_get_addr_ = true;
2083 // Do a relocation in which we convert a TLS Initial-Exec to a
2087 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2089 Output_segment* tls_segment,
2090 const elfcpp::Rel<32, false>& rel,
2091 unsigned int r_type,
2092 elfcpp::Elf_types<32>::Elf_Addr value,
2093 unsigned char* view,
2094 section_size_type view_size)
2096 // We have to actually change the instructions, which means that we
2097 // need to examine the opcodes to figure out which instruction we
2099 if (r_type == elfcpp::R_386_TLS_IE)
2101 // movl %gs:XX,%eax ==> movl $YY,%eax
2102 // movl %gs:XX,%reg ==> movl $YY,%reg
2103 // addl %gs:XX,%reg ==> addl $YY,%reg
2104 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2105 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2107 unsigned char op1 = view[-1];
2110 // movl XX,%eax ==> movl $YY,%eax
2115 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2117 unsigned char op2 = view[-2];
2120 // movl XX,%reg ==> movl $YY,%reg
2121 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2122 (op1 & 0xc7) == 0x05);
2124 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2126 else if (op2 == 0x03)
2128 // addl XX,%reg ==> addl $YY,%reg
2129 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2130 (op1 & 0xc7) == 0x05);
2132 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2135 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2140 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2141 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2142 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2143 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2144 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2146 unsigned char op1 = view[-1];
2147 unsigned char op2 = view[-2];
2148 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2149 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2152 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2154 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2156 else if (op2 == 0x2b)
2158 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2160 view[-1] = 0xe8 | ((op1 >> 3) & 7);
2162 else if (op2 == 0x03)
2164 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2166 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2169 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2172 value = tls_segment->memsz() - value;
2173 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2176 Relocate_functions<32, false>::rel32(view, value);
2179 // Relocate section data.
2182 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2183 unsigned int sh_type,
2184 const unsigned char* prelocs,
2186 Output_section* output_section,
2187 bool needs_special_offset_handling,
2188 unsigned char* view,
2189 elfcpp::Elf_types<32>::Elf_Addr address,
2190 section_size_type view_size)
2192 gold_assert(sh_type == elfcpp::SHT_REL);
2194 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2195 Target_i386::Relocate>(
2201 needs_special_offset_handling,
2207 // Return the size of a relocation while scanning during a relocatable
2211 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2212 unsigned int r_type,
2217 case elfcpp::R_386_NONE:
2218 case elfcpp::R_386_GNU_VTINHERIT:
2219 case elfcpp::R_386_GNU_VTENTRY:
2220 case elfcpp::R_386_TLS_GD: // Global-dynamic
2221 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2222 case elfcpp::R_386_TLS_DESC_CALL:
2223 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2224 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2225 case elfcpp::R_386_TLS_IE: // Initial-exec
2226 case elfcpp::R_386_TLS_IE_32:
2227 case elfcpp::R_386_TLS_GOTIE:
2228 case elfcpp::R_386_TLS_LE: // Local-exec
2229 case elfcpp::R_386_TLS_LE_32:
2232 case elfcpp::R_386_32:
2233 case elfcpp::R_386_PC32:
2234 case elfcpp::R_386_GOT32:
2235 case elfcpp::R_386_PLT32:
2236 case elfcpp::R_386_GOTOFF:
2237 case elfcpp::R_386_GOTPC:
2240 case elfcpp::R_386_16:
2241 case elfcpp::R_386_PC16:
2244 case elfcpp::R_386_8:
2245 case elfcpp::R_386_PC8:
2248 // These are relocations which should only be seen by the
2249 // dynamic linker, and should never be seen here.
2250 case elfcpp::R_386_COPY:
2251 case elfcpp::R_386_GLOB_DAT:
2252 case elfcpp::R_386_JUMP_SLOT:
2253 case elfcpp::R_386_RELATIVE:
2254 case elfcpp::R_386_TLS_TPOFF:
2255 case elfcpp::R_386_TLS_DTPMOD32:
2256 case elfcpp::R_386_TLS_DTPOFF32:
2257 case elfcpp::R_386_TLS_TPOFF32:
2258 case elfcpp::R_386_TLS_DESC:
2259 object->error(_("unexpected reloc %u in object file"), r_type);
2262 case elfcpp::R_386_32PLT:
2263 case elfcpp::R_386_TLS_GD_32:
2264 case elfcpp::R_386_TLS_GD_PUSH:
2265 case elfcpp::R_386_TLS_GD_CALL:
2266 case elfcpp::R_386_TLS_GD_POP:
2267 case elfcpp::R_386_TLS_LDM_32:
2268 case elfcpp::R_386_TLS_LDM_PUSH:
2269 case elfcpp::R_386_TLS_LDM_CALL:
2270 case elfcpp::R_386_TLS_LDM_POP:
2271 case elfcpp::R_386_USED_BY_INTEL_200:
2273 object->error(_("unsupported reloc %u in object file"), r_type);
2278 // Scan the relocs during a relocatable link.
2281 Target_i386::scan_relocatable_relocs(const General_options& options,
2282 Symbol_table* symtab,
2284 Sized_relobj<32, false>* object,
2285 unsigned int data_shndx,
2286 unsigned int sh_type,
2287 const unsigned char* prelocs,
2289 Output_section* output_section,
2290 bool needs_special_offset_handling,
2291 size_t local_symbol_count,
2292 const unsigned char* plocal_symbols,
2293 Relocatable_relocs* rr)
2295 gold_assert(sh_type == elfcpp::SHT_REL);
2297 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2298 Relocatable_size_for_reloc> Scan_relocatable_relocs;
2300 gold::scan_relocatable_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2301 Scan_relocatable_relocs>(
2310 needs_special_offset_handling,
2316 // Relocate a section during a relocatable link.
2319 Target_i386::relocate_for_relocatable(
2320 const Relocate_info<32, false>* relinfo,
2321 unsigned int sh_type,
2322 const unsigned char* prelocs,
2324 Output_section* output_section,
2325 off_t offset_in_output_section,
2326 const Relocatable_relocs* rr,
2327 unsigned char* view,
2328 elfcpp::Elf_types<32>::Elf_Addr view_address,
2329 section_size_type view_size,
2330 unsigned char* reloc_view,
2331 section_size_type reloc_view_size)
2333 gold_assert(sh_type == elfcpp::SHT_REL);
2335 gold::relocate_for_relocatable<32, false, Target_i386, elfcpp::SHT_REL>(
2340 offset_in_output_section,
2349 // Return the value to use for a dynamic which requires special
2350 // treatment. This is how we support equality comparisons of function
2351 // pointers across shared library boundaries, as described in the
2352 // processor specific ABI supplement.
2355 Target_i386::do_dynsym_value(const Symbol* gsym) const
2357 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2358 return this->plt_section()->address() + gsym->plt_offset();
2361 // Return a string used to fill a code section with nops to take up
2362 // the specified length.
2365 Target_i386::do_code_fill(section_size_type length)
2369 // Build a jmp instruction to skip over the bytes.
2370 unsigned char jmp[5];
2372 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2373 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2374 + std::string(length - 5, '\0'));
2377 // Nop sequences of various lengths.
2378 const char nop1[1] = { 0x90 }; // nop
2379 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
2380 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2381 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2382 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2383 0x00 }; // leal 0(%esi,1),%esi
2384 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2386 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2388 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2389 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2390 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2391 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2393 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2394 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2396 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2397 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2399 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2400 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2401 0x00, 0x00, 0x00, 0x00 };
2402 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2403 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2404 0x27, 0x00, 0x00, 0x00,
2406 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2407 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2408 0xbc, 0x27, 0x00, 0x00,
2410 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2411 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2412 0x90, 0x90, 0x90, 0x90,
2415 const char* nops[16] = {
2417 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2418 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2421 return std::string(nops[length], length);
2424 // The selector for i386 object files.
2426 class Target_selector_i386 : public Target_selector
2429 Target_selector_i386()
2430 : Target_selector(elfcpp::EM_386, 32, false)
2434 recognize(int machine, int osabi, int abiversion);
2437 recognize_by_name(const char* name);
2440 Target_i386* target_;
2443 // Recognize an i386 object file when we already know that the machine
2444 // number is EM_386.
2447 Target_selector_i386::recognize(int, int, int)
2449 if (this->target_ == NULL)
2450 this->target_ = new Target_i386();
2451 return this->target_;
2455 Target_selector_i386::recognize_by_name(const char* name)
2457 if (strcmp(name, "elf32-i386") != 0)
2459 if (this->target_ == NULL)
2460 this->target_ = new Target_i386();
2461 return this->target_;
2464 Target_selector_i386 target_selector_i386;
2466 } // End anonymous namespace.