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"
44 class Output_data_plt_i386;
46 // The i386 target class.
48 class Target_i386 : public Sized_target<32, false>
51 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
54 : Sized_target<32, false>(&i386_info),
55 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
56 copy_relocs_(NULL), dynbss_(NULL)
59 // Scan the relocations to look for symbol adjustments.
61 scan_relocs(const General_options& options,
64 Sized_relobj<32, false>* object,
65 unsigned int data_shndx,
67 const unsigned char* prelocs,
69 size_t local_symbol_count,
70 const unsigned char* plocal_symbols,
71 Symbol** global_symbols);
73 // Finalize the sections.
75 do_finalize_sections(Layout*);
77 // Return the value to use for a dynamic which requires special
80 do_dynsym_value(const Symbol*) const;
82 // Relocate a section.
84 relocate_section(const Relocate_info<32, false>*,
86 const unsigned char* prelocs,
89 elfcpp::Elf_types<32>::Elf_Addr view_address,
92 // Return a string used to fill a code section with nops.
94 do_code_fill(off_t length);
97 // The class which scans relocations.
101 local(const General_options& options, Symbol_table* symtab,
102 Layout* layout, Target_i386* target,
103 Sized_relobj<32, false>* object,
104 unsigned int data_shndx,
105 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
106 const elfcpp::Sym<32, false>& lsym);
109 global(const General_options& options, Symbol_table* symtab,
110 Layout* layout, Target_i386* target,
111 Sized_relobj<32, false>* object,
112 unsigned int data_shndx,
113 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
117 // The class which implements relocation.
122 : skip_call_tls_get_addr_(false),
123 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
128 if (this->skip_call_tls_get_addr_)
130 // FIXME: This needs to specify the location somehow.
131 fprintf(stderr, _("%s: missing expected TLS relocation\n"),
137 // Do a relocation. Return false if the caller should not issue
138 // any warnings about this relocation.
140 relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
141 const elfcpp::Rel<32, false>&,
142 unsigned int r_type, const Sized_symbol<32>*,
143 const Symbol_value<32>*,
144 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
148 // Do a TLS relocation.
150 relocate_tls(const Relocate_info<32, false>*, size_t relnum,
151 const elfcpp::Rel<32, false>&,
152 unsigned int r_type, const Sized_symbol<32>*,
153 const Symbol_value<32>*,
154 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);
156 // Do a TLS Initial-Exec to Local-Exec transition.
158 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
159 Output_segment* tls_segment,
160 const elfcpp::Rel<32, false>&, unsigned int r_type,
161 elfcpp::Elf_types<32>::Elf_Addr value,
165 // Do a TLS Global-Dynamic to Local-Exec transition.
167 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
168 Output_segment* tls_segment,
169 const elfcpp::Rel<32, false>&, unsigned int r_type,
170 elfcpp::Elf_types<32>::Elf_Addr value,
174 // Do a TLS Local-Dynamic to Local-Exec transition.
176 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
177 Output_segment* tls_segment,
178 const elfcpp::Rel<32, false>&, unsigned int r_type,
179 elfcpp::Elf_types<32>::Elf_Addr value,
183 // Check the range for a TLS relocation.
185 check_range(const Relocate_info<32, false>*, size_t relnum,
186 const elfcpp::Rel<32, false>&, off_t, off_t);
188 // Check the validity of a TLS relocation. This is like assert.
190 check_tls(const Relocate_info<32, false>*, size_t relnum,
191 const elfcpp::Rel<32, false>&, bool);
193 // We need to keep track of which type of local dynamic relocation
194 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
195 enum Local_dynamic_type
202 // This is set if we should skip the next reloc, which should be a
203 // PLT32 reloc against ___tls_get_addr.
204 bool skip_call_tls_get_addr_;
205 // The type of local dynamic relocation we have seen in the section
206 // being relocated, if any.
207 Local_dynamic_type local_dynamic_type_;
210 // Adjust TLS relocation type based on the options and whether this
211 // is a local symbol.
213 optimize_tls_reloc(bool is_final, int r_type);
215 // Get the GOT section, creating it if necessary.
216 Output_data_got<32, false>*
217 got_section(Symbol_table*, Layout*);
219 // Create a PLT entry for a global symbol.
221 make_plt_entry(Symbol_table*, Layout*, Symbol*);
223 // Get the PLT section.
224 const Output_data_plt_i386*
227 gold_assert(this->plt_ != NULL);
231 // Get the dynamic reloc section, creating it if necessary.
233 rel_dyn_section(Layout*);
235 // Copy a relocation against a global symbol.
237 copy_reloc(const General_options*, Symbol_table*, Layout*,
238 Sized_relobj<32, false>*, unsigned int,
239 Symbol*, const elfcpp::Rel<32, false>&);
241 // Information about this specific target which we pass to the
242 // general Target structure.
243 static const Target::Target_info i386_info;
246 Output_data_got<32, false>* got_;
248 Output_data_plt_i386* plt_;
249 // The GOT PLT section.
250 Output_data_space* got_plt_;
251 // The dynamic reloc section.
252 Reloc_section* rel_dyn_;
253 // Relocs saved to avoid a COPY reloc.
254 Copy_relocs<32, false>* copy_relocs_;
255 // Space for variables copied with a COPY reloc.
256 Output_data_space* dynbss_;
259 const Target::Target_info Target_i386::i386_info =
262 false, // is_big_endian
263 elfcpp::EM_386, // machine_code
264 false, // has_make_symbol
265 false, // has_resolve
266 true, // has_code_fill
267 "/usr/lib/libc.so.1", // dynamic_linker
268 0x08048000, // text_segment_address
269 0x1000, // abi_pagesize
270 0x1000 // common_pagesize
273 // Get the GOT section, creating it if necessary.
275 Output_data_got<32, false>*
276 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
278 if (this->got_ == NULL)
280 gold_assert(symtab != NULL && layout != NULL);
282 this->got_ = new Output_data_got<32, false>();
284 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
285 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
288 // The old GNU linker creates a .got.plt section. We just
289 // create another set of data in the .got section. Note that we
290 // always create a PLT if we create a GOT, although the PLT
292 this->got_plt_ = new Output_data_space(4);
293 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
294 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
297 // The first three entries are reserved.
298 this->got_plt_->set_space_size(3 * 4);
300 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
301 symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
303 0, 0, elfcpp::STT_OBJECT,
305 elfcpp::STV_HIDDEN, 0,
312 // Get the dynamic reloc section, creating it if necessary.
314 Target_i386::Reloc_section*
315 Target_i386::rel_dyn_section(Layout* layout)
317 if (this->rel_dyn_ == NULL)
319 gold_assert(layout != NULL);
320 this->rel_dyn_ = new Reloc_section();
321 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
322 elfcpp::SHF_ALLOC, this->rel_dyn_);
324 return this->rel_dyn_;
327 // A class to handle the PLT data.
329 class Output_data_plt_i386 : public Output_section_data
332 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
334 Output_data_plt_i386(Layout*, Output_data_space*);
336 // Add an entry to the PLT.
338 add_entry(Symbol* gsym);
340 // Return the .rel.plt section data.
343 { return this->rel_; }
347 do_adjust_output_section(Output_section* os);
350 // The size of an entry in the PLT.
351 static const int plt_entry_size = 16;
353 // The first entry in the PLT for an executable.
354 static unsigned char exec_first_plt_entry[plt_entry_size];
356 // The first entry in the PLT for a shared object.
357 static unsigned char dyn_first_plt_entry[plt_entry_size];
359 // Other entries in the PLT for an executable.
360 static unsigned char exec_plt_entry[plt_entry_size];
362 // Other entries in the PLT for a shared object.
363 static unsigned char dyn_plt_entry[plt_entry_size];
365 // Set the final size.
367 do_set_address(uint64_t, off_t)
368 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
370 // Write out the PLT data.
372 do_write(Output_file*);
374 // The reloc section.
376 // The .got.plt section.
377 Output_data_space* got_plt_;
378 // The number of PLT entries.
382 // Create the PLT section. The ordinary .got section is an argument,
383 // since we need to refer to the start. We also create our own .got
384 // section just for PLT entries.
386 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
387 Output_data_space* got_plt)
388 : Output_section_data(4), got_plt_(got_plt), count_(0)
390 this->rel_ = new Reloc_section();
391 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
392 elfcpp::SHF_ALLOC, this->rel_);
396 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
398 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
399 // linker, and so do we.
403 // Add an entry to the PLT.
406 Output_data_plt_i386::add_entry(Symbol* gsym)
408 gold_assert(!gsym->has_plt_offset());
410 // Note that when setting the PLT offset we skip the initial
411 // reserved PLT entry.
412 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
416 off_t got_offset = this->got_plt_->data_size();
418 // Every PLT entry needs a GOT entry which points back to the PLT
419 // entry (this will be changed by the dynamic linker, normally
420 // lazily when the function is called).
421 this->got_plt_->set_space_size(got_offset + 4);
423 // Every PLT entry needs a reloc.
424 gsym->set_needs_dynsym_entry();
425 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
428 // Note that we don't need to save the symbol. The contents of the
429 // PLT are independent of which symbols are used. The symbols only
430 // appear in the relocations.
433 // The first entry in the PLT for an executable.
435 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
437 0xff, 0x35, // pushl contents of memory address
438 0, 0, 0, 0, // replaced with address of .got + 4
439 0xff, 0x25, // jmp indirect
440 0, 0, 0, 0, // replaced with address of .got + 8
444 // The first entry in the PLT for a shared object.
446 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
448 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
449 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
453 // Subsequent entries in the PLT for an executable.
455 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
457 0xff, 0x25, // jmp indirect
458 0, 0, 0, 0, // replaced with address of symbol in .got
459 0x68, // pushl immediate
460 0, 0, 0, 0, // replaced with offset into relocation table
461 0xe9, // jmp relative
462 0, 0, 0, 0 // replaced with offset to start of .plt
465 // Subsequent entries in the PLT for a shared object.
467 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
469 0xff, 0xa3, // jmp *offset(%ebx)
470 0, 0, 0, 0, // replaced with offset of symbol in .got
471 0x68, // pushl immediate
472 0, 0, 0, 0, // replaced with offset into relocation table
473 0xe9, // jmp relative
474 0, 0, 0, 0 // replaced with offset to start of .plt
477 // Write out the PLT. This uses the hand-coded instructions above,
478 // and adjusts them as needed. This is all specified by the i386 ELF
479 // Processor Supplement.
482 Output_data_plt_i386::do_write(Output_file* of)
484 const off_t offset = this->offset();
485 const off_t oview_size = this->data_size();
486 unsigned char* const oview = of->get_output_view(offset, oview_size);
488 const off_t got_file_offset = this->got_plt_->offset();
489 const off_t got_size = this->got_plt_->data_size();
490 unsigned char* const got_view = of->get_output_view(got_file_offset,
493 unsigned char* pov = oview;
495 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
496 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
498 if (parameters->output_is_shared())
499 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
502 memcpy(pov, exec_first_plt_entry, plt_entry_size);
503 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
504 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
506 pov += plt_entry_size;
508 unsigned char* got_pov = got_view;
510 memset(got_pov, 0, 12);
513 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
515 unsigned int plt_offset = plt_entry_size;
516 unsigned int plt_rel_offset = 0;
517 unsigned int got_offset = 12;
518 const unsigned int count = this->count_;
519 for (unsigned int i = 0;
522 pov += plt_entry_size,
524 plt_offset += plt_entry_size,
525 plt_rel_offset += rel_size,
528 // Set and adjust the PLT entry itself.
530 if (parameters->output_is_shared())
532 memcpy(pov, dyn_plt_entry, plt_entry_size);
533 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
537 memcpy(pov, exec_plt_entry, plt_entry_size);
538 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
543 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
544 elfcpp::Swap<32, false>::writeval(pov + 12,
545 - (plt_offset + plt_entry_size));
547 // Set the entry in the GOT.
548 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
551 gold_assert(pov - oview == oview_size);
552 gold_assert(got_pov - got_view == got_size);
554 of->write_output_view(offset, oview_size, oview);
555 of->write_output_view(got_file_offset, got_size, got_view);
558 // Create a PLT entry for a global symbol.
561 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
563 if (gsym->has_plt_offset())
566 if (this->plt_ == NULL)
568 // Create the GOT sections first.
569 this->got_section(symtab, layout);
571 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
572 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
574 | elfcpp::SHF_EXECINSTR),
578 this->plt_->add_entry(gsym);
581 // Handle a relocation against a non-function symbol defined in a
582 // dynamic object. The traditional way to handle this is to generate
583 // a COPY relocation to copy the variable at runtime from the shared
584 // object into the executable's data segment. However, this is
585 // undesirable in general, as if the size of the object changes in the
586 // dynamic object, the executable will no longer work correctly. If
587 // this relocation is in a writable section, then we can create a
588 // dynamic reloc and the dynamic linker will resolve it to the correct
589 // address at runtime. However, we do not want do that if the
590 // relocation is in a read-only section, as it would prevent the
591 // readonly segment from being shared. And if we have to eventually
592 // generate a COPY reloc, then any dynamic relocations will be
593 // useless. So this means that if this is a writable section, we need
594 // to save the relocation until we see whether we have to create a
595 // COPY relocation for this symbol for any other relocation.
598 Target_i386::copy_reloc(const General_options* options,
599 Symbol_table* symtab,
601 Sized_relobj<32, false>* object,
602 unsigned int data_shndx, Symbol* gsym,
603 const elfcpp::Rel<32, false>& rel)
605 Sized_symbol<32>* ssym;
606 ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
609 if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
612 // So far we do not need a COPY reloc. Save this relocation.
613 // If it turns out that we never need a COPY reloc for this
614 // symbol, then we will emit the relocation.
615 if (this->copy_relocs_ == NULL)
616 this->copy_relocs_ = new Copy_relocs<32, false>();
617 this->copy_relocs_->save(ssym, object, data_shndx, rel);
621 // Allocate space for this symbol in the .bss section.
623 elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
625 // There is no defined way to determine the required alignment
626 // of the symbol. We pick the alignment based on the size. We
627 // set an arbitrary maximum of 256.
629 for (align = 1; align < 512; align <<= 1)
630 if ((symsize & align) != 0)
633 if (this->dynbss_ == NULL)
635 this->dynbss_ = new Output_data_space(align);
636 layout->add_output_section_data(".bss",
639 | elfcpp::SHF_WRITE),
643 Output_data_space* dynbss = this->dynbss_;
645 if (align > dynbss->addralign())
646 dynbss->set_space_alignment(align);
648 off_t dynbss_size = dynbss->data_size();
649 dynbss_size = align_address(dynbss_size, align);
650 off_t offset = dynbss_size;
651 dynbss->set_space_size(dynbss_size + symsize);
653 // Define the symbol in the .dynbss section.
654 symtab->define_in_output_data(this, ssym->name(), ssym->version(),
655 dynbss, offset, symsize, ssym->type(),
656 ssym->binding(), ssym->visibility(),
657 ssym->nonvis(), false, false);
659 // Add the COPY reloc.
660 ssym->set_needs_dynsym_entry();
661 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
662 rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
666 // Optimize the TLS relocation type based on what we know about the
667 // symbol. IS_FINAL is true if the final address of this symbol is
668 // known at link time.
671 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
673 // If we are generating a shared library, then we can't do anything
675 if (parameters->output_is_shared())
680 case elfcpp::R_386_TLS_GD:
681 case elfcpp::R_386_TLS_GOTDESC:
682 case elfcpp::R_386_TLS_DESC_CALL:
683 // These are Global-Dynamic which permits fully general TLS
684 // access. Since we know that we are generating an executable,
685 // we can convert this to Initial-Exec. If we also know that
686 // this is a local symbol, we can further switch to Local-Exec.
688 return elfcpp::R_386_TLS_LE_32;
689 return elfcpp::R_386_TLS_IE_32;
691 case elfcpp::R_386_TLS_LDM:
692 // This is Local-Dynamic, which refers to a local symbol in the
693 // dynamic TLS block. Since we know that we generating an
694 // executable, we can switch to Local-Exec.
695 return elfcpp::R_386_TLS_LE_32;
697 case elfcpp::R_386_TLS_LDO_32:
698 // Another type of Local-Dynamic relocation. We return a
699 // different value as we need to negate the thread segment
700 // offset. FIXME: Returning reloc types makes no sense.
701 return elfcpp::R_386_TLS_LE;
703 case elfcpp::R_386_TLS_IE:
704 case elfcpp::R_386_TLS_GOTIE:
705 case elfcpp::R_386_TLS_IE_32:
706 // These are Initial-Exec relocs which get the thread offset
707 // from the GOT. If we know that we are linking against the
708 // local symbol, we can switch to Local-Exec, which links the
709 // thread offset into the instruction.
711 return elfcpp::R_386_TLS_LE_32;
714 case elfcpp::R_386_TLS_LE:
715 case elfcpp::R_386_TLS_LE_32:
716 // When we already have Local-Exec, there is nothing further we
725 // Scan a relocation for a local symbol.
728 Target_i386::Scan::local(const General_options&,
729 Symbol_table* symtab,
732 Sized_relobj<32, false>* object,
734 const elfcpp::Rel<32, false>&,
736 const elfcpp::Sym<32, false>&)
740 case elfcpp::R_386_NONE:
741 case elfcpp::R_386_GNU_VTINHERIT:
742 case elfcpp::R_386_GNU_VTENTRY:
745 case elfcpp::R_386_32:
746 case elfcpp::R_386_16:
747 case elfcpp::R_386_8:
748 // FIXME: If we are generating a shared object we need to copy
749 // this relocation into the object.
750 gold_assert(!parameters->output_is_shared());
753 case elfcpp::R_386_PC32:
754 case elfcpp::R_386_PC16:
755 case elfcpp::R_386_PC8:
758 case elfcpp::R_386_GOTOFF:
759 case elfcpp::R_386_GOTPC:
760 // We need a GOT section.
761 target->got_section(symtab, layout);
764 case elfcpp::R_386_COPY:
765 case elfcpp::R_386_GLOB_DAT:
766 case elfcpp::R_386_JUMP_SLOT:
767 case elfcpp::R_386_RELATIVE:
768 // These are outstanding tls relocs, which are unexpected when
770 case elfcpp::R_386_TLS_TPOFF:
771 case elfcpp::R_386_TLS_DTPMOD32:
772 case elfcpp::R_386_TLS_DTPOFF32:
773 case elfcpp::R_386_TLS_TPOFF32:
774 case elfcpp::R_386_TLS_DESC:
775 fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
776 program_name, object->name().c_str(), r_type);
780 // These are initial tls relocs, which are expected when
782 case elfcpp::R_386_TLS_IE:
783 case elfcpp::R_386_TLS_GOTIE:
784 case elfcpp::R_386_TLS_LE:
785 case elfcpp::R_386_TLS_GD:
786 case elfcpp::R_386_TLS_LDM:
787 case elfcpp::R_386_TLS_LDO_32:
788 case elfcpp::R_386_TLS_IE_32:
789 case elfcpp::R_386_TLS_LE_32:
790 case elfcpp::R_386_TLS_GOTDESC:
791 case elfcpp::R_386_TLS_DESC_CALL:
793 bool output_is_shared = parameters->output_is_shared();
794 r_type = Target_i386::optimize_tls_reloc(!output_is_shared,
798 case elfcpp::R_386_TLS_LE:
799 case elfcpp::R_386_TLS_LE_32:
800 // FIXME: If generating a shared object, we need to copy
801 // this relocation into the object.
802 gold_assert(!output_is_shared);
805 case elfcpp::R_386_TLS_LDM:
806 case elfcpp::R_386_TLS_LDO_32:
809 case elfcpp::R_386_TLS_IE:
810 case elfcpp::R_386_TLS_GOTIE:
811 case elfcpp::R_386_TLS_GD:
812 case elfcpp::R_386_TLS_IE_32:
813 case elfcpp::R_386_TLS_GOTDESC:
814 case elfcpp::R_386_TLS_DESC_CALL:
816 _("%s: %s: unsupported reloc %u against local symbol\n"),
817 program_name, object->name().c_str(), r_type);
823 case elfcpp::R_386_GOT32:
824 case elfcpp::R_386_PLT32:
825 case elfcpp::R_386_32PLT:
826 case elfcpp::R_386_TLS_GD_32:
827 case elfcpp::R_386_TLS_GD_PUSH:
828 case elfcpp::R_386_TLS_GD_CALL:
829 case elfcpp::R_386_TLS_GD_POP:
830 case elfcpp::R_386_TLS_LDM_32:
831 case elfcpp::R_386_TLS_LDM_PUSH:
832 case elfcpp::R_386_TLS_LDM_CALL:
833 case elfcpp::R_386_TLS_LDM_POP:
834 case elfcpp::R_386_USED_BY_INTEL_200:
836 fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"),
837 program_name, object->name().c_str(), r_type);
842 // Scan a relocation for a global symbol.
845 Target_i386::Scan::global(const General_options& options,
846 Symbol_table* symtab,
849 Sized_relobj<32, false>* object,
850 unsigned int data_shndx,
851 const elfcpp::Rel<32, false>& reloc,
857 case elfcpp::R_386_NONE:
858 case elfcpp::R_386_GNU_VTINHERIT:
859 case elfcpp::R_386_GNU_VTENTRY:
862 case elfcpp::R_386_32:
863 case elfcpp::R_386_PC32:
864 case elfcpp::R_386_16:
865 case elfcpp::R_386_PC16:
866 case elfcpp::R_386_8:
867 case elfcpp::R_386_PC8:
868 // FIXME: If we are generating a shared object we may need to
869 // copy this relocation into the object. If this symbol is
870 // defined in a shared object, we may need to copy this
871 // relocation in order to avoid a COPY relocation.
872 gold_assert(!parameters->output_is_shared());
874 if (gsym->is_from_dynobj())
876 // This symbol is defined in a dynamic object. If it is a
877 // function, we make a PLT entry. Otherwise we need to
878 // either generate a COPY reloc or copy this reloc.
879 if (gsym->type() == elfcpp::STT_FUNC)
881 target->make_plt_entry(symtab, layout, gsym);
883 // If this is not a PC relative reference, then we may
884 // be taking the address of the function. In that case
885 // we need to set the entry in the dynamic symbol table
886 // to the address of the PLT entry.
887 if (r_type != elfcpp::R_386_PC32
888 && r_type != elfcpp::R_386_PC16
889 && r_type != elfcpp::R_386_PC8)
890 gsym->set_needs_dynsym_value();
893 target->copy_reloc(&options, symtab, layout, object, data_shndx,
899 case elfcpp::R_386_GOT32:
901 // The symbol requires a GOT entry.
902 Output_data_got<32, false>* got = target->got_section(symtab, layout);
903 if (got->add_global(gsym))
905 // If this symbol is not fully resolved, we need to add a
906 // dynamic relocation for it.
907 if (!gsym->final_value_is_known())
909 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
910 rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got,
917 case elfcpp::R_386_PLT32:
918 // If the symbol is fully resolved, this is just a PC32 reloc.
919 // Otherwise we need a PLT entry.
920 if (gsym->final_value_is_known())
922 target->make_plt_entry(symtab, layout, gsym);
925 case elfcpp::R_386_GOTOFF:
926 case elfcpp::R_386_GOTPC:
927 // We need a GOT section.
928 target->got_section(symtab, layout);
931 case elfcpp::R_386_COPY:
932 case elfcpp::R_386_GLOB_DAT:
933 case elfcpp::R_386_JUMP_SLOT:
934 case elfcpp::R_386_RELATIVE:
935 // These are outstanding tls relocs, which are unexpected when
937 case elfcpp::R_386_TLS_TPOFF:
938 case elfcpp::R_386_TLS_DTPMOD32:
939 case elfcpp::R_386_TLS_DTPOFF32:
940 case elfcpp::R_386_TLS_TPOFF32:
941 case elfcpp::R_386_TLS_DESC:
942 fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
943 program_name, object->name().c_str(), r_type);
947 // These are initial tls relocs, which are expected when
949 case elfcpp::R_386_TLS_IE:
950 case elfcpp::R_386_TLS_GOTIE:
951 case elfcpp::R_386_TLS_LE:
952 case elfcpp::R_386_TLS_GD:
953 case elfcpp::R_386_TLS_LDM:
954 case elfcpp::R_386_TLS_LDO_32:
955 case elfcpp::R_386_TLS_IE_32:
956 case elfcpp::R_386_TLS_LE_32:
957 case elfcpp::R_386_TLS_GOTDESC:
958 case elfcpp::R_386_TLS_DESC_CALL:
960 const bool is_final = gsym->final_value_is_known();
961 r_type = Target_i386::optimize_tls_reloc(is_final, r_type);
964 case elfcpp::R_386_TLS_LE:
965 case elfcpp::R_386_TLS_LE_32:
966 // FIXME: If generating a shared object, we need to copy
967 // this relocation into the object.
968 gold_assert(!parameters->output_is_shared());
971 case elfcpp::R_386_TLS_LDM:
972 case elfcpp::R_386_TLS_LDO_32:
975 case elfcpp::R_386_TLS_IE:
976 case elfcpp::R_386_TLS_GOTIE:
977 case elfcpp::R_386_TLS_GD:
978 case elfcpp::R_386_TLS_IE_32:
979 case elfcpp::R_386_TLS_GOTDESC:
980 case elfcpp::R_386_TLS_DESC_CALL:
982 _("%s: %s: unsupported reloc %u "
983 "against global symbol %s\n"),
984 program_name, object->name().c_str(), r_type,
991 case elfcpp::R_386_32PLT:
992 case elfcpp::R_386_TLS_GD_32:
993 case elfcpp::R_386_TLS_GD_PUSH:
994 case elfcpp::R_386_TLS_GD_CALL:
995 case elfcpp::R_386_TLS_GD_POP:
996 case elfcpp::R_386_TLS_LDM_32:
997 case elfcpp::R_386_TLS_LDM_PUSH:
998 case elfcpp::R_386_TLS_LDM_CALL:
999 case elfcpp::R_386_TLS_LDM_POP:
1000 case elfcpp::R_386_USED_BY_INTEL_200:
1003 _("%s: %s: unsupported reloc %u against global symbol %s\n"),
1004 program_name, object->name().c_str(), r_type, gsym->name());
1009 // Scan relocations for a section.
1012 Target_i386::scan_relocs(const General_options& options,
1013 Symbol_table* symtab,
1015 Sized_relobj<32, false>* object,
1016 unsigned int data_shndx,
1017 unsigned int sh_type,
1018 const unsigned char* prelocs,
1020 size_t local_symbol_count,
1021 const unsigned char* plocal_symbols,
1022 Symbol** global_symbols)
1024 if (sh_type == elfcpp::SHT_RELA)
1026 fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"),
1027 program_name, object->name().c_str());
1031 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1046 // Finalize the sections.
1049 Target_i386::do_finalize_sections(Layout* layout)
1051 // Fill in some more dynamic tags.
1052 Output_data_dynamic* const odyn = layout->dynamic_data();
1055 if (this->got_plt_ != NULL)
1056 odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1058 if (this->plt_ != NULL)
1060 const Output_data* od = this->plt_->rel_plt();
1061 odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1062 odyn->add_section_address(elfcpp::DT_JMPREL, od);
1063 odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1066 if (this->rel_dyn_ != NULL)
1068 const Output_data* od = this->rel_dyn_;
1069 odyn->add_section_address(elfcpp::DT_REL, od);
1070 odyn->add_section_size(elfcpp::DT_RELSZ, od);
1071 odyn->add_constant(elfcpp::DT_RELENT,
1072 elfcpp::Elf_sizes<32>::rel_size);
1075 if (!parameters->output_is_shared())
1077 // The value of the DT_DEBUG tag is filled in by the dynamic
1078 // linker at run time, and used by the debugger.
1079 odyn->add_constant(elfcpp::DT_DEBUG, 0);
1083 // Emit any relocs we saved in an attempt to avoid generating COPY
1085 if (this->copy_relocs_ == NULL)
1087 if (this->copy_relocs_->any_to_emit())
1089 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1090 this->copy_relocs_->emit(rel_dyn);
1092 delete this->copy_relocs_;
1093 this->copy_relocs_ = NULL;
1096 // Perform a relocation.
1099 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1100 Target_i386* target,
1102 const elfcpp::Rel<32, false>& rel,
1103 unsigned int r_type,
1104 const Sized_symbol<32>* gsym,
1105 const Symbol_value<32>* psymval,
1106 unsigned char* view,
1107 elfcpp::Elf_types<32>::Elf_Addr address,
1110 if (this->skip_call_tls_get_addr_)
1112 if (r_type != elfcpp::R_386_PLT32
1114 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1116 fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"),
1118 relinfo->location(relnum, rel.get_r_offset()).c_str());
1122 this->skip_call_tls_get_addr_ = false;
1127 // Pick the value to use for symbols defined in shared objects.
1128 Symbol_value<32> symval;
1129 if (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset())
1131 symval.set_output_value(target->plt_section()->address()
1132 + gsym->plt_offset());
1136 const Sized_relobj<32, false>* object = relinfo->object;
1140 case elfcpp::R_386_NONE:
1141 case elfcpp::R_386_GNU_VTINHERIT:
1142 case elfcpp::R_386_GNU_VTENTRY:
1145 case elfcpp::R_386_32:
1146 Relocate_functions<32, false>::rel32(view, object, psymval);
1149 case elfcpp::R_386_PC32:
1150 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1153 case elfcpp::R_386_16:
1154 Relocate_functions<32, false>::rel16(view, object, psymval);
1157 case elfcpp::R_386_PC16:
1158 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1161 case elfcpp::R_386_8:
1162 Relocate_functions<32, false>::rel8(view, object, psymval);
1165 case elfcpp::R_386_PC8:
1166 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1169 case elfcpp::R_386_PLT32:
1170 gold_assert(gsym->has_plt_offset()
1171 || gsym->final_value_is_known());
1172 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1175 case elfcpp::R_386_GOT32:
1176 // Local GOT offsets not yet supported.
1178 gold_assert(gsym->has_got_offset());
1179 Relocate_functions<32, false>::rel32(view, gsym->got_offset());
1182 case elfcpp::R_386_GOTOFF:
1184 elfcpp::Elf_types<32>::Elf_Addr value;
1185 value = (psymval->value(object, 0)
1186 - target->got_section(NULL, NULL)->address());
1187 Relocate_functions<32, false>::rel32(view, value);
1191 case elfcpp::R_386_GOTPC:
1193 elfcpp::Elf_types<32>::Elf_Addr value;
1194 value = target->got_section(NULL, NULL)->address();
1195 Relocate_functions<32, false>::pcrel32(view, value, address);
1199 case elfcpp::R_386_COPY:
1200 case elfcpp::R_386_GLOB_DAT:
1201 case elfcpp::R_386_JUMP_SLOT:
1202 case elfcpp::R_386_RELATIVE:
1203 // These are outstanding tls relocs, which are unexpected when
1205 case elfcpp::R_386_TLS_TPOFF:
1206 case elfcpp::R_386_TLS_DTPMOD32:
1207 case elfcpp::R_386_TLS_DTPOFF32:
1208 case elfcpp::R_386_TLS_TPOFF32:
1209 case elfcpp::R_386_TLS_DESC:
1210 fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
1212 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1217 // These are initial tls relocs, which are expected when
1219 case elfcpp::R_386_TLS_IE:
1220 case elfcpp::R_386_TLS_GOTIE:
1221 case elfcpp::R_386_TLS_LE:
1222 case elfcpp::R_386_TLS_GD:
1223 case elfcpp::R_386_TLS_LDM:
1224 case elfcpp::R_386_TLS_LDO_32:
1225 case elfcpp::R_386_TLS_IE_32:
1226 case elfcpp::R_386_TLS_LE_32:
1227 case elfcpp::R_386_TLS_GOTDESC:
1228 case elfcpp::R_386_TLS_DESC_CALL:
1229 this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view,
1230 address, view_size);
1233 case elfcpp::R_386_32PLT:
1234 case elfcpp::R_386_TLS_GD_32:
1235 case elfcpp::R_386_TLS_GD_PUSH:
1236 case elfcpp::R_386_TLS_GD_CALL:
1237 case elfcpp::R_386_TLS_GD_POP:
1238 case elfcpp::R_386_TLS_LDM_32:
1239 case elfcpp::R_386_TLS_LDM_PUSH:
1240 case elfcpp::R_386_TLS_LDM_CALL:
1241 case elfcpp::R_386_TLS_LDM_POP:
1242 case elfcpp::R_386_USED_BY_INTEL_200:
1244 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1246 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1248 // gold_exit(false);
1255 // Perform a TLS relocation.
1258 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1260 const elfcpp::Rel<32, false>& rel,
1261 unsigned int r_type,
1262 const Sized_symbol<32>* gsym,
1263 const Symbol_value<32>* psymval,
1264 unsigned char* view,
1265 elfcpp::Elf_types<32>::Elf_Addr,
1268 Output_segment* tls_segment = relinfo->layout->tls_segment();
1269 if (tls_segment == NULL)
1271 fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"),
1273 relinfo->location(relnum, rel.get_r_offset()).c_str());
1277 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0);
1279 const bool is_final = (gsym == NULL
1280 ? !parameters->output_is_shared()
1281 : gsym->final_value_is_known());
1282 const unsigned int opt_r_type =
1283 Target_i386::optimize_tls_reloc(is_final, r_type);
1286 case elfcpp::R_386_TLS_LE_32:
1287 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1288 Relocate_functions<32, false>::rel32(view, value);
1291 case elfcpp::R_386_TLS_LE:
1292 value = value - (tls_segment->vaddr() + tls_segment->memsz());
1293 Relocate_functions<32, false>::rel32(view, value);
1296 case elfcpp::R_386_TLS_IE:
1297 case elfcpp::R_386_TLS_GOTIE:
1298 case elfcpp::R_386_TLS_IE_32:
1299 if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1301 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1302 rel, r_type, value, view,
1306 fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"),
1308 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1310 // gold_exit(false);
1313 case elfcpp::R_386_TLS_GD:
1314 if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1316 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1317 rel, r_type, value, view,
1321 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1323 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1325 // gold_exit(false);
1328 case elfcpp::R_386_TLS_LDM:
1329 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1332 _("%s: %s: both SUN and GNU model TLS relocations\n"),
1334 relinfo->location(relnum, rel.get_r_offset()).c_str());
1337 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1338 if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1340 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1341 value, view, view_size);
1344 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1346 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1348 // gold_exit(false);
1351 case elfcpp::R_386_TLS_LDO_32:
1352 // This reloc can appear in debugging sections, in which case we
1353 // won't see the TLS_LDM reloc. The local_dynamic_type field
1355 if (opt_r_type == elfcpp::R_386_TLS_LDO_32
1356 || this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE)
1357 value = value - tls_segment->vaddr();
1358 else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU)
1359 value = value - (tls_segment->vaddr() + tls_segment->memsz());
1361 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1362 Relocate_functions<32, false>::rel32(view, value);
1365 case elfcpp::R_386_TLS_GOTDESC:
1366 case elfcpp::R_386_TLS_DESC_CALL:
1367 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1369 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1371 // gold_exit(false);
1376 // Do a relocation in which we convert a TLS Initial-Exec to a
1380 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
1382 Output_segment* tls_segment,
1383 const elfcpp::Rel<32, false>& rel,
1384 unsigned int r_type,
1385 elfcpp::Elf_types<32>::Elf_Addr value,
1386 unsigned char* view,
1389 // We have to actually change the instructions, which means that we
1390 // need to examine the opcodes to figure out which instruction we
1392 if (r_type == elfcpp::R_386_TLS_IE)
1394 // movl %gs:XX,%eax ==> movl $YY,%eax
1395 // movl %gs:XX,%reg ==> movl $YY,%reg
1396 // addl %gs:XX,%reg ==> addl $YY,%reg
1397 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1);
1398 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
1400 unsigned char op1 = view[-1];
1403 // movl XX,%eax ==> movl $YY,%eax
1408 Target_i386::Relocate::check_range(relinfo, relnum, rel,
1411 unsigned char op2 = view[-2];
1414 // movl XX,%reg ==> movl $YY,%reg
1415 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1416 (op1 & 0xc7) == 0x05);
1418 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1420 else if (op2 == 0x03)
1422 // addl XX,%reg ==> addl $YY,%reg
1423 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1424 (op1 & 0xc7) == 0x05);
1426 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1429 Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
1434 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
1435 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
1436 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
1437 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1438 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
1440 unsigned char op1 = view[-1];
1441 unsigned char op2 = view[-2];
1442 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1443 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
1446 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
1448 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1450 else if (op2 == 0x2b)
1452 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
1454 view[-1] = 0xe8 | ((op1 >> 3) & 7);
1456 else if (op2 == 0x03)
1458 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
1460 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1463 Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
1466 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1467 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
1470 Relocate_functions<32, false>::rel32(view, value);
1473 // Do a relocation in which we convert a TLS Global-Dynamic to a
1477 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1479 Output_segment* tls_segment,
1480 const elfcpp::Rel<32, false>& rel,
1482 elfcpp::Elf_types<32>::Elf_Addr value,
1483 unsigned char* view,
1486 // leal foo(,%reg,1),%eax; call ___tls_get_addr
1487 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1488 // leal foo(%reg),%eax; call ___tls_get_addr
1489 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1491 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1492 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9);
1494 unsigned char op1 = view[-1];
1495 unsigned char op2 = view[-2];
1497 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1498 op2 == 0x8d || op2 == 0x04);
1499 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1506 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3);
1507 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1509 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1510 ((op1 & 0xc7) == 0x05
1511 && op1 != (4 << 3)));
1512 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1516 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1517 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1518 if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size
1521 // There is a trailing nop. Use the size byte subl.
1522 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1527 // Use the five byte subl.
1528 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1532 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1533 Relocate_functions<32, false>::rel32(view + roff, value);
1535 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1537 this->skip_call_tls_get_addr_ = true;
1540 // Do a relocation in which we convert a TLS Local-Dynamic to a
1544 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
1547 const elfcpp::Rel<32, false>& rel,
1549 elfcpp::Elf_types<32>::Elf_Addr,
1550 unsigned char* view,
1553 // leal foo(%reg), %eax; call ___tls_get_addr
1554 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
1556 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1557 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9);
1559 // FIXME: Does this test really always pass?
1560 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1561 view[-2] == 0x8d && view[-1] == 0x83);
1563 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1566 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
1568 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1570 this->skip_call_tls_get_addr_ = true;
1573 // Check the range for a TLS relocation.
1576 Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo,
1578 const elfcpp::Rel<32, false>& rel,
1579 off_t view_size, off_t off)
1581 off_t offset = rel.get_r_offset() + off;
1582 if (offset < 0 || offset > view_size)
1584 fprintf(stderr, _("%s: %s: TLS relocation out of range\n"),
1586 relinfo->location(relnum, rel.get_r_offset()).c_str());
1591 // Check the validity of a TLS relocation. This is like assert.
1594 Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo,
1596 const elfcpp::Rel<32, false>& rel,
1602 _("%s: %s: TLS relocation against invalid instruction\n"),
1604 relinfo->location(relnum, rel.get_r_offset()).c_str());
1609 // Relocate section data.
1612 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
1613 unsigned int sh_type,
1614 const unsigned char* prelocs,
1616 unsigned char* view,
1617 elfcpp::Elf_types<32>::Elf_Addr address,
1620 gold_assert(sh_type == elfcpp::SHT_REL);
1622 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
1623 Target_i386::Relocate>(
1633 // Return the value to use for a dynamic which requires special
1634 // treatment. This is how we support equality comparisons of function
1635 // pointers across shared library boundaries, as described in the
1636 // processor specific ABI supplement.
1639 Target_i386::do_dynsym_value(const Symbol* gsym) const
1641 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
1642 return this->plt_section()->address() + gsym->plt_offset();
1645 // Return a string used to fill a code section with nops to take up
1646 // the specified length.
1649 Target_i386::do_code_fill(off_t length)
1653 // Build a jmp instruction to skip over the bytes.
1654 unsigned char jmp[5];
1656 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
1657 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
1658 + std::string(length - 5, '\0'));
1661 // Nop sequences of various lengths.
1662 const char nop1[1] = { 0x90 }; // nop
1663 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
1664 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1665 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1666 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1667 0x00 }; // leal 0(%esi,1),%esi
1668 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1670 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1672 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1673 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1674 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1675 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1677 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1678 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1680 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1681 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1683 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1684 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1685 0x00, 0x00, 0x00, 0x00 };
1686 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1687 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1688 0x27, 0x00, 0x00, 0x00,
1690 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1691 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1692 0xbc, 0x27, 0x00, 0x00,
1694 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1695 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1696 0x90, 0x90, 0x90, 0x90,
1699 const char* nops[16] = {
1701 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
1702 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
1705 return std::string(nops[length], length);
1708 // The selector for i386 object files.
1710 class Target_selector_i386 : public Target_selector
1713 Target_selector_i386()
1714 : Target_selector(elfcpp::EM_386, 32, false)
1718 recognize(int machine, int osabi, int abiversion);
1721 Target_i386* target_;
1724 // Recognize an i386 object file when we already know that the machine
1725 // number is EM_386.
1728 Target_selector_i386::recognize(int, int, int)
1730 if (this->target_ == NULL)
1731 this->target_ = new Target_i386();
1732 return this->target_;
1735 Target_selector_i386 target_selector_i386;
1737 } // End anonymous namespace.