1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
28 #include "parameters.h"
35 #include "copy-relocs.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
46 class Output_data_plt_i386
;
48 // The i386 target class.
49 // TLS info comes from
50 // http://people.redhat.com/drepper/tls.pdf
51 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
53 class Target_i386
: public Sized_target
<32, false>
56 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
59 : Sized_target
<32, false>(&i386_info
),
60 got_(NULL
), plt_(NULL
), got_plt_(NULL
), rel_dyn_(NULL
),
61 copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
62 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
65 // Scan the relocations to look for symbol adjustments.
67 scan_relocs(const General_options
& options
,
70 Sized_relobj
<32, false>* object
,
71 unsigned int data_shndx
,
73 const unsigned char* prelocs
,
75 Output_section
* output_section
,
76 bool needs_special_offset_handling
,
77 size_t local_symbol_count
,
78 const unsigned char* plocal_symbols
);
80 // Finalize the sections.
82 do_finalize_sections(Layout
*);
84 // Return the value to use for a dynamic which requires special
87 do_dynsym_value(const Symbol
*) const;
89 // Relocate a section.
91 relocate_section(const Relocate_info
<32, false>*,
93 const unsigned char* prelocs
,
95 Output_section
* output_section
,
96 bool needs_special_offset_handling
,
98 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
99 section_size_type view_size
);
101 // Scan the relocs during a relocatable link.
103 scan_relocatable_relocs(const General_options
& options
,
104 Symbol_table
* symtab
,
106 Sized_relobj
<32, false>* object
,
107 unsigned int data_shndx
,
108 unsigned int sh_type
,
109 const unsigned char* prelocs
,
111 Output_section
* output_section
,
112 bool needs_special_offset_handling
,
113 size_t local_symbol_count
,
114 const unsigned char* plocal_symbols
,
115 Relocatable_relocs
*);
117 // Relocate a section during a relocatable link.
119 relocate_for_relocatable(const Relocate_info
<32, false>*,
120 unsigned int sh_type
,
121 const unsigned char* prelocs
,
123 Output_section
* output_section
,
124 off_t offset_in_output_section
,
125 const Relocatable_relocs
*,
127 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
128 section_size_type view_size
,
129 unsigned char* reloc_view
,
130 section_size_type reloc_view_size
);
132 // Return a string used to fill a code section with nops.
134 do_code_fill(section_size_type length
) const;
136 // Return whether SYM is defined by the ABI.
138 do_is_defined_by_abi(Symbol
* sym
) const
139 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
141 // Return the size of the GOT section.
145 gold_assert(this->got_
!= NULL
);
146 return this->got_
->data_size();
150 // The class which scans relocations.
154 local(const General_options
& options
, Symbol_table
* symtab
,
155 Layout
* layout
, Target_i386
* target
,
156 Sized_relobj
<32, false>* object
,
157 unsigned int data_shndx
,
158 Output_section
* output_section
,
159 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
160 const elfcpp::Sym
<32, false>& lsym
);
163 global(const General_options
& options
, Symbol_table
* symtab
,
164 Layout
* layout
, Target_i386
* target
,
165 Sized_relobj
<32, false>* object
,
166 unsigned int data_shndx
,
167 Output_section
* output_section
,
168 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
172 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
175 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
179 // The class which implements relocation.
184 : skip_call_tls_get_addr_(false),
185 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
190 if (this->skip_call_tls_get_addr_
)
192 // FIXME: This needs to specify the location somehow.
193 gold_error(_("missing expected TLS relocation"));
197 // Return whether the static relocation needs to be applied.
199 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
203 // Do a relocation. Return false if the caller should not issue
204 // any warnings about this relocation.
206 relocate(const Relocate_info
<32, false>*, Target_i386
*, size_t relnum
,
207 const elfcpp::Rel
<32, false>&,
208 unsigned int r_type
, const Sized_symbol
<32>*,
209 const Symbol_value
<32>*,
210 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
214 // Do a TLS relocation.
216 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
217 size_t relnum
, const elfcpp::Rel
<32, false>&,
218 unsigned int r_type
, const Sized_symbol
<32>*,
219 const Symbol_value
<32>*,
220 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
223 // Do a TLS General-Dynamic to Initial-Exec transition.
225 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
226 Output_segment
* tls_segment
,
227 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
228 elfcpp::Elf_types
<32>::Elf_Addr value
,
230 section_size_type view_size
);
232 // Do a TLS General-Dynamic to Local-Exec transition.
234 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
235 Output_segment
* tls_segment
,
236 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
237 elfcpp::Elf_types
<32>::Elf_Addr value
,
239 section_size_type view_size
);
241 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
244 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
245 Output_segment
* tls_segment
,
246 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
247 elfcpp::Elf_types
<32>::Elf_Addr value
,
249 section_size_type view_size
);
251 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
254 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
255 Output_segment
* tls_segment
,
256 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
257 elfcpp::Elf_types
<32>::Elf_Addr value
,
259 section_size_type view_size
);
261 // Do a TLS Local-Dynamic to Local-Exec transition.
263 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
264 Output_segment
* tls_segment
,
265 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
266 elfcpp::Elf_types
<32>::Elf_Addr value
,
268 section_size_type view_size
);
270 // Do a TLS Initial-Exec to Local-Exec transition.
272 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
273 Output_segment
* tls_segment
,
274 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
275 elfcpp::Elf_types
<32>::Elf_Addr value
,
277 section_size_type view_size
);
279 // We need to keep track of which type of local dynamic relocation
280 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
281 enum Local_dynamic_type
288 // This is set if we should skip the next reloc, which should be a
289 // PLT32 reloc against ___tls_get_addr.
290 bool skip_call_tls_get_addr_
;
291 // The type of local dynamic relocation we have seen in the section
292 // being relocated, if any.
293 Local_dynamic_type local_dynamic_type_
;
296 // A class which returns the size required for a relocation type,
297 // used while scanning relocs during a relocatable link.
298 class Relocatable_size_for_reloc
302 get_size_for_reloc(unsigned int, Relobj
*);
305 // Adjust TLS relocation type based on the options and whether this
306 // is a local symbol.
307 static tls::Tls_optimization
308 optimize_tls_reloc(bool is_final
, int r_type
);
310 // Get the GOT section, creating it if necessary.
311 Output_data_got
<32, false>*
312 got_section(Symbol_table
*, Layout
*);
314 // Get the GOT PLT section.
316 got_plt_section() const
318 gold_assert(this->got_plt_
!= NULL
);
319 return this->got_plt_
;
322 // Create a PLT entry for a global symbol.
324 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
326 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
328 define_tls_base_symbol(Symbol_table
*, Layout
*);
330 // Create a GOT entry for the TLS module index.
332 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
333 Sized_relobj
<32, false>* object
);
335 // Get the PLT section.
336 const Output_data_plt_i386
*
339 gold_assert(this->plt_
!= NULL
);
343 // Get the dynamic reloc section, creating it if necessary.
345 rel_dyn_section(Layout
*);
347 // Return true if the symbol may need a COPY relocation.
348 // References from an executable object to non-function symbols
349 // defined in a dynamic object may need a COPY relocation.
351 may_need_copy_reloc(Symbol
* gsym
)
353 return (!parameters
->options().shared()
354 && gsym
->is_from_dynobj()
355 && gsym
->type() != elfcpp::STT_FUNC
);
358 // Add a potential copy relocation.
360 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
361 Sized_relobj
<32, false>* object
,
362 unsigned int shndx
, Output_section
* output_section
,
363 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
365 this->copy_relocs_
.copy_reloc(symtab
, layout
,
366 symtab
->get_sized_symbol
<32>(sym
),
367 object
, shndx
, output_section
, reloc
,
368 this->rel_dyn_section(layout
));
371 // Information about this specific target which we pass to the
372 // general Target structure.
373 static const Target::Target_info i386_info
;
375 // The types of GOT entries needed for this platform.
378 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
379 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
380 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
381 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
382 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
386 Output_data_got
<32, false>* got_
;
388 Output_data_plt_i386
* plt_
;
389 // The GOT PLT section.
390 Output_data_space
* got_plt_
;
391 // The dynamic reloc section.
392 Reloc_section
* rel_dyn_
;
393 // Relocs saved to avoid a COPY reloc.
394 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
395 // Space for variables copied with a COPY reloc.
396 Output_data_space
* dynbss_
;
397 // Offset of the GOT entry for the TLS module index.
398 unsigned int got_mod_index_offset_
;
399 // True if the _TLS_MODULE_BASE_ symbol has been defined.
400 bool tls_base_symbol_defined_
;
403 const Target::Target_info
Target_i386::i386_info
=
406 false, // is_big_endian
407 elfcpp::EM_386
, // machine_code
408 false, // has_make_symbol
409 false, // has_resolve
410 true, // has_code_fill
411 true, // is_default_stack_executable
413 "/usr/lib/libc.so.1", // dynamic_linker
414 0x08048000, // default_text_segment_address
415 0x1000, // abi_pagesize (overridable by -z max-page-size)
416 0x1000 // common_pagesize (overridable by -z common-page-size)
419 // Get the GOT section, creating it if necessary.
421 Output_data_got
<32, false>*
422 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
424 if (this->got_
== NULL
)
426 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
428 this->got_
= new Output_data_got
<32, false>();
431 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
433 | elfcpp::SHF_WRITE
),
437 // The old GNU linker creates a .got.plt section. We just
438 // create another set of data in the .got section. Note that we
439 // always create a PLT if we create a GOT, although the PLT
441 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
442 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
444 | elfcpp::SHF_WRITE
),
448 // The first three entries are reserved.
449 this->got_plt_
->set_current_data_size(3 * 4);
451 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
452 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
454 0, 0, elfcpp::STT_OBJECT
,
456 elfcpp::STV_HIDDEN
, 0,
463 // Get the dynamic reloc section, creating it if necessary.
465 Target_i386::Reloc_section
*
466 Target_i386::rel_dyn_section(Layout
* layout
)
468 if (this->rel_dyn_
== NULL
)
470 gold_assert(layout
!= NULL
);
471 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
472 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
473 elfcpp::SHF_ALLOC
, this->rel_dyn_
);
475 return this->rel_dyn_
;
478 // A class to handle the PLT data.
480 class Output_data_plt_i386
: public Output_section_data
483 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
485 Output_data_plt_i386(Layout
*, Output_data_space
*);
487 // Add an entry to the PLT.
489 add_entry(Symbol
* gsym
);
491 // Return the .rel.plt section data.
494 { return this->rel_
; }
498 do_adjust_output_section(Output_section
* os
);
500 // Write to a map file.
502 do_print_to_mapfile(Mapfile
* mapfile
) const
503 { mapfile
->print_output_data(this, _("** PLT")); }
506 // The size of an entry in the PLT.
507 static const int plt_entry_size
= 16;
509 // The first entry in the PLT for an executable.
510 static unsigned char exec_first_plt_entry
[plt_entry_size
];
512 // The first entry in the PLT for a shared object.
513 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
515 // Other entries in the PLT for an executable.
516 static unsigned char exec_plt_entry
[plt_entry_size
];
518 // Other entries in the PLT for a shared object.
519 static unsigned char dyn_plt_entry
[plt_entry_size
];
521 // Set the final size.
523 set_final_data_size()
524 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
526 // Write out the PLT data.
528 do_write(Output_file
*);
530 // The reloc section.
532 // The .got.plt section.
533 Output_data_space
* got_plt_
;
534 // The number of PLT entries.
538 // Create the PLT section. The ordinary .got section is an argument,
539 // since we need to refer to the start. We also create our own .got
540 // section just for PLT entries.
542 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
543 Output_data_space
* got_plt
)
544 : Output_section_data(4), got_plt_(got_plt
), count_(0)
546 this->rel_
= new Reloc_section(false);
547 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
548 elfcpp::SHF_ALLOC
, this->rel_
);
552 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
554 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
555 // linker, and so do we.
559 // Add an entry to the PLT.
562 Output_data_plt_i386::add_entry(Symbol
* gsym
)
564 gold_assert(!gsym
->has_plt_offset());
566 // Note that when setting the PLT offset we skip the initial
567 // reserved PLT entry.
568 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
572 section_offset_type got_offset
= this->got_plt_
->current_data_size();
574 // Every PLT entry needs a GOT entry which points back to the PLT
575 // entry (this will be changed by the dynamic linker, normally
576 // lazily when the function is called).
577 this->got_plt_
->set_current_data_size(got_offset
+ 4);
579 // Every PLT entry needs a reloc.
580 gsym
->set_needs_dynsym_entry();
581 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
584 // Note that we don't need to save the symbol. The contents of the
585 // PLT are independent of which symbols are used. The symbols only
586 // appear in the relocations.
589 // The first entry in the PLT for an executable.
591 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
593 0xff, 0x35, // pushl contents of memory address
594 0, 0, 0, 0, // replaced with address of .got + 4
595 0xff, 0x25, // jmp indirect
596 0, 0, 0, 0, // replaced with address of .got + 8
600 // The first entry in the PLT for a shared object.
602 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
604 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
605 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
609 // Subsequent entries in the PLT for an executable.
611 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
613 0xff, 0x25, // jmp indirect
614 0, 0, 0, 0, // replaced with address of symbol in .got
615 0x68, // pushl immediate
616 0, 0, 0, 0, // replaced with offset into relocation table
617 0xe9, // jmp relative
618 0, 0, 0, 0 // replaced with offset to start of .plt
621 // Subsequent entries in the PLT for a shared object.
623 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
625 0xff, 0xa3, // jmp *offset(%ebx)
626 0, 0, 0, 0, // replaced with offset of symbol in .got
627 0x68, // pushl immediate
628 0, 0, 0, 0, // replaced with offset into relocation table
629 0xe9, // jmp relative
630 0, 0, 0, 0 // replaced with offset to start of .plt
633 // Write out the PLT. This uses the hand-coded instructions above,
634 // and adjusts them as needed. This is all specified by the i386 ELF
635 // Processor Supplement.
638 Output_data_plt_i386::do_write(Output_file
* of
)
640 const off_t offset
= this->offset();
641 const section_size_type oview_size
=
642 convert_to_section_size_type(this->data_size());
643 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
645 const off_t got_file_offset
= this->got_plt_
->offset();
646 const section_size_type got_size
=
647 convert_to_section_size_type(this->got_plt_
->data_size());
648 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
651 unsigned char* pov
= oview
;
653 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
654 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
656 if (parameters
->options().shared())
657 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
660 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
661 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
662 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
664 pov
+= plt_entry_size
;
666 unsigned char* got_pov
= got_view
;
668 memset(got_pov
, 0, 12);
671 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
673 unsigned int plt_offset
= plt_entry_size
;
674 unsigned int plt_rel_offset
= 0;
675 unsigned int got_offset
= 12;
676 const unsigned int count
= this->count_
;
677 for (unsigned int i
= 0;
680 pov
+= plt_entry_size
,
682 plt_offset
+= plt_entry_size
,
683 plt_rel_offset
+= rel_size
,
686 // Set and adjust the PLT entry itself.
688 if (parameters
->options().shared())
690 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
691 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
695 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
696 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
701 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
702 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
703 - (plt_offset
+ plt_entry_size
));
705 // Set the entry in the GOT.
706 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
709 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
710 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
712 of
->write_output_view(offset
, oview_size
, oview
);
713 of
->write_output_view(got_file_offset
, got_size
, got_view
);
716 // Create a PLT entry for a global symbol.
719 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
721 if (gsym
->has_plt_offset())
724 if (this->plt_
== NULL
)
726 // Create the GOT sections first.
727 this->got_section(symtab
, layout
);
729 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
730 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
732 | elfcpp::SHF_EXECINSTR
),
736 this->plt_
->add_entry(gsym
);
739 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
742 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
744 if (this->tls_base_symbol_defined_
)
747 Output_segment
* tls_segment
= layout
->tls_segment();
748 if (tls_segment
!= NULL
)
750 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
754 elfcpp::STV_HIDDEN
, 0,
755 Symbol::SEGMENT_END
, true);
757 this->tls_base_symbol_defined_
= true;
760 // Create a GOT entry for the TLS module index.
763 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
764 Sized_relobj
<32, false>* object
)
766 if (this->got_mod_index_offset_
== -1U)
768 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
769 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
770 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
771 unsigned int got_offset
= got
->add_constant(0);
772 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
774 got
->add_constant(0);
775 this->got_mod_index_offset_
= got_offset
;
777 return this->got_mod_index_offset_
;
780 // Optimize the TLS relocation type based on what we know about the
781 // symbol. IS_FINAL is true if the final address of this symbol is
782 // known at link time.
784 tls::Tls_optimization
785 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
787 // If we are generating a shared library, then we can't do anything
789 if (parameters
->options().shared())
790 return tls::TLSOPT_NONE
;
794 case elfcpp::R_386_TLS_GD
:
795 case elfcpp::R_386_TLS_GOTDESC
:
796 case elfcpp::R_386_TLS_DESC_CALL
:
797 // These are General-Dynamic which permits fully general TLS
798 // access. Since we know that we are generating an executable,
799 // we can convert this to Initial-Exec. If we also know that
800 // this is a local symbol, we can further switch to Local-Exec.
802 return tls::TLSOPT_TO_LE
;
803 return tls::TLSOPT_TO_IE
;
805 case elfcpp::R_386_TLS_LDM
:
806 // This is Local-Dynamic, which refers to a local symbol in the
807 // dynamic TLS block. Since we know that we generating an
808 // executable, we can switch to Local-Exec.
809 return tls::TLSOPT_TO_LE
;
811 case elfcpp::R_386_TLS_LDO_32
:
812 // Another type of Local-Dynamic relocation.
813 return tls::TLSOPT_TO_LE
;
815 case elfcpp::R_386_TLS_IE
:
816 case elfcpp::R_386_TLS_GOTIE
:
817 case elfcpp::R_386_TLS_IE_32
:
818 // These are Initial-Exec relocs which get the thread offset
819 // from the GOT. If we know that we are linking against the
820 // local symbol, we can switch to Local-Exec, which links the
821 // thread offset into the instruction.
823 return tls::TLSOPT_TO_LE
;
824 return tls::TLSOPT_NONE
;
826 case elfcpp::R_386_TLS_LE
:
827 case elfcpp::R_386_TLS_LE_32
:
828 // When we already have Local-Exec, there is nothing further we
830 return tls::TLSOPT_NONE
;
837 // Report an unsupported relocation against a local symbol.
840 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
843 gold_error(_("%s: unsupported reloc %u against local symbol"),
844 object
->name().c_str(), r_type
);
847 // Scan a relocation for a local symbol.
850 Target_i386::Scan::local(const General_options
&,
851 Symbol_table
* symtab
,
854 Sized_relobj
<32, false>* object
,
855 unsigned int data_shndx
,
856 Output_section
* output_section
,
857 const elfcpp::Rel
<32, false>& reloc
,
859 const elfcpp::Sym
<32, false>& lsym
)
863 case elfcpp::R_386_NONE
:
864 case elfcpp::R_386_GNU_VTINHERIT
:
865 case elfcpp::R_386_GNU_VTENTRY
:
868 case elfcpp::R_386_32
:
869 // If building a shared library (or a position-independent
870 // executable), we need to create a dynamic relocation for
871 // this location. The relocation applied at link time will
872 // apply the link-time value, so we flag the location with
873 // an R_386_RELATIVE relocation so the dynamic loader can
874 // relocate it easily.
875 if (parameters
->options().output_is_position_independent())
877 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
878 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
879 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
880 output_section
, data_shndx
,
881 reloc
.get_r_offset());
885 case elfcpp::R_386_16
:
886 case elfcpp::R_386_8
:
887 // If building a shared library (or a position-independent
888 // executable), we need to create a dynamic relocation for
889 // this location. Because the addend needs to remain in the
890 // data section, we need to be careful not to apply this
891 // relocation statically.
892 if (parameters
->options().output_is_position_independent())
894 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
895 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
896 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
897 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
898 data_shndx
, reloc
.get_r_offset());
901 gold_assert(lsym
.get_st_value() == 0);
902 unsigned int shndx
= lsym
.get_st_shndx();
904 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
907 object
->error(_("section symbol %u has bad shndx %u"),
910 rel_dyn
->add_local_section(object
, 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
, GOT_TYPE_STANDARD
))
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
->options().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(
947 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
948 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
954 // These are relocations which should only be seen by the
955 // dynamic linker, and should never be seen here.
956 case elfcpp::R_386_COPY
:
957 case elfcpp::R_386_GLOB_DAT
:
958 case elfcpp::R_386_JUMP_SLOT
:
959 case elfcpp::R_386_RELATIVE
:
960 case elfcpp::R_386_TLS_TPOFF
:
961 case elfcpp::R_386_TLS_DTPMOD32
:
962 case elfcpp::R_386_TLS_DTPOFF32
:
963 case elfcpp::R_386_TLS_TPOFF32
:
964 case elfcpp::R_386_TLS_DESC
:
965 gold_error(_("%s: unexpected reloc %u in object file"),
966 object
->name().c_str(), r_type
);
969 // These are initial TLS relocs, which are expected when
971 case elfcpp::R_386_TLS_GD
: // Global-dynamic
972 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
973 case elfcpp::R_386_TLS_DESC_CALL
:
974 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
975 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
976 case elfcpp::R_386_TLS_IE
: // Initial-exec
977 case elfcpp::R_386_TLS_IE_32
:
978 case elfcpp::R_386_TLS_GOTIE
:
979 case elfcpp::R_386_TLS_LE
: // Local-exec
980 case elfcpp::R_386_TLS_LE_32
:
982 bool output_is_shared
= parameters
->options().shared();
983 const tls::Tls_optimization optimized_type
984 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
987 case elfcpp::R_386_TLS_GD
: // Global-dynamic
988 if (optimized_type
== tls::TLSOPT_NONE
)
990 // Create a pair of GOT entries for the module index and
991 // dtv-relative offset.
992 Output_data_got
<32, false>* got
993 = target
->got_section(symtab
, layout
);
994 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
995 unsigned int shndx
= lsym
.get_st_shndx();
997 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
999 object
->error(_("local symbol %u has bad shndx %u"),
1002 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1004 target
->rel_dyn_section(layout
),
1005 elfcpp::R_386_TLS_DTPMOD32
, 0);
1007 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1008 unsupported_reloc_local(object
, r_type
);
1011 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1012 target
->define_tls_base_symbol(symtab
, layout
);
1013 if (optimized_type
== tls::TLSOPT_NONE
)
1015 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1016 Output_data_got
<32, false>* got
1017 = target
->got_section(symtab
, layout
);
1018 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1019 unsigned int shndx
= lsym
.get_st_shndx();
1021 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1023 object
->error(_("local symbol %u has bad shndx %u"),
1026 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1028 target
->rel_dyn_section(layout
),
1029 elfcpp::R_386_TLS_DESC
, 0);
1031 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1032 unsupported_reloc_local(object
, r_type
);
1035 case elfcpp::R_386_TLS_DESC_CALL
:
1038 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1039 if (optimized_type
== tls::TLSOPT_NONE
)
1041 // Create a GOT entry for the module index.
1042 target
->got_mod_index_entry(symtab
, layout
, object
);
1044 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1045 unsupported_reloc_local(object
, r_type
);
1048 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1051 case elfcpp::R_386_TLS_IE
: // Initial-exec
1052 case elfcpp::R_386_TLS_IE_32
:
1053 case elfcpp::R_386_TLS_GOTIE
:
1054 layout
->set_has_static_tls();
1055 if (optimized_type
== tls::TLSOPT_NONE
)
1057 // For the R_386_TLS_IE relocation, we need to create a
1058 // dynamic relocation when building a shared library.
1059 if (r_type
== elfcpp::R_386_TLS_IE
1060 && parameters
->options().shared())
1062 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1064 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1065 rel_dyn
->add_local_relative(object
, r_sym
,
1066 elfcpp::R_386_RELATIVE
,
1067 output_section
, data_shndx
,
1068 reloc
.get_r_offset());
1070 // Create a GOT entry for the tp-relative offset.
1071 Output_data_got
<32, false>* got
1072 = target
->got_section(symtab
, layout
);
1073 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1074 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1075 ? elfcpp::R_386_TLS_TPOFF32
1076 : elfcpp::R_386_TLS_TPOFF
);
1077 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1078 ? GOT_TYPE_TLS_OFFSET
1079 : GOT_TYPE_TLS_NOFFSET
);
1080 got
->add_local_with_rel(object
, r_sym
, got_type
,
1081 target
->rel_dyn_section(layout
),
1084 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1085 unsupported_reloc_local(object
, r_type
);
1088 case elfcpp::R_386_TLS_LE
: // Local-exec
1089 case elfcpp::R_386_TLS_LE_32
:
1090 layout
->set_has_static_tls();
1091 if (output_is_shared
)
1093 // We need to create a dynamic relocation.
1094 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1095 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1096 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1097 ? elfcpp::R_386_TLS_TPOFF32
1098 : elfcpp::R_386_TLS_TPOFF
);
1099 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1100 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1101 data_shndx
, reloc
.get_r_offset());
1111 case elfcpp::R_386_32PLT
:
1112 case elfcpp::R_386_TLS_GD_32
:
1113 case elfcpp::R_386_TLS_GD_PUSH
:
1114 case elfcpp::R_386_TLS_GD_CALL
:
1115 case elfcpp::R_386_TLS_GD_POP
:
1116 case elfcpp::R_386_TLS_LDM_32
:
1117 case elfcpp::R_386_TLS_LDM_PUSH
:
1118 case elfcpp::R_386_TLS_LDM_CALL
:
1119 case elfcpp::R_386_TLS_LDM_POP
:
1120 case elfcpp::R_386_USED_BY_INTEL_200
:
1122 unsupported_reloc_local(object
, r_type
);
1127 // Report an unsupported relocation against a global symbol.
1130 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1131 unsigned int r_type
,
1134 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1135 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1138 // Scan a relocation for a global symbol.
1141 Target_i386::Scan::global(const General_options
&,
1142 Symbol_table
* symtab
,
1144 Target_i386
* target
,
1145 Sized_relobj
<32, false>* object
,
1146 unsigned int data_shndx
,
1147 Output_section
* output_section
,
1148 const elfcpp::Rel
<32, false>& reloc
,
1149 unsigned int r_type
,
1154 case elfcpp::R_386_NONE
:
1155 case elfcpp::R_386_GNU_VTINHERIT
:
1156 case elfcpp::R_386_GNU_VTENTRY
:
1159 case elfcpp::R_386_32
:
1160 case elfcpp::R_386_16
:
1161 case elfcpp::R_386_8
:
1163 // Make a PLT entry if necessary.
1164 if (gsym
->needs_plt_entry())
1166 target
->make_plt_entry(symtab
, layout
, gsym
);
1167 // Since this is not a PC-relative relocation, we may be
1168 // taking the address of a function. In that case we need to
1169 // set the entry in the dynamic symbol table to the address of
1171 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1172 gsym
->set_needs_dynsym_value();
1174 // Make a dynamic relocation if necessary.
1175 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1177 if (target
->may_need_copy_reloc(gsym
))
1179 target
->copy_reloc(symtab
, layout
, object
,
1180 data_shndx
, output_section
, gsym
, reloc
);
1182 else if (r_type
== elfcpp::R_386_32
1183 && gsym
->can_use_relative_reloc(false))
1185 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1186 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1187 output_section
, object
,
1188 data_shndx
, reloc
.get_r_offset());
1192 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1193 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1194 data_shndx
, reloc
.get_r_offset());
1200 case elfcpp::R_386_PC32
:
1201 case elfcpp::R_386_PC16
:
1202 case elfcpp::R_386_PC8
:
1204 // Make a PLT entry if necessary.
1205 if (gsym
->needs_plt_entry())
1207 // These relocations are used for function calls only in
1208 // non-PIC code. For a 32-bit relocation in a shared library,
1209 // we'll need a text relocation anyway, so we can skip the
1210 // PLT entry and let the dynamic linker bind the call directly
1211 // to the target. For smaller relocations, we should use a
1212 // PLT entry to ensure that the call can reach.
1213 if (!parameters
->options().shared()
1214 || r_type
!= elfcpp::R_386_PC32
)
1215 target
->make_plt_entry(symtab
, layout
, gsym
);
1217 // Make a dynamic relocation if necessary.
1218 int flags
= Symbol::NON_PIC_REF
;
1219 if (gsym
->type() == elfcpp::STT_FUNC
)
1220 flags
|= Symbol::FUNCTION_CALL
;
1221 if (gsym
->needs_dynamic_reloc(flags
))
1223 if (target
->may_need_copy_reloc(gsym
))
1225 target
->copy_reloc(symtab
, layout
, object
,
1226 data_shndx
, output_section
, gsym
, reloc
);
1230 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1231 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1232 data_shndx
, reloc
.get_r_offset());
1238 case elfcpp::R_386_GOT32
:
1240 // The symbol requires a GOT entry.
1241 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1242 if (gsym
->final_value_is_known())
1243 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1246 // If this symbol is not fully resolved, we need to add a
1247 // GOT entry with a dynamic relocation.
1248 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1249 if (gsym
->is_from_dynobj()
1250 || gsym
->is_undefined()
1251 || gsym
->is_preemptible())
1252 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1253 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1256 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1257 rel_dyn
->add_global_relative(
1258 gsym
, elfcpp::R_386_RELATIVE
, got
,
1259 gsym
->got_offset(GOT_TYPE_STANDARD
));
1265 case elfcpp::R_386_PLT32
:
1266 // If the symbol is fully resolved, this is just a PC32 reloc.
1267 // Otherwise we need a PLT entry.
1268 if (gsym
->final_value_is_known())
1270 // If building a shared library, we can also skip the PLT entry
1271 // if the symbol is defined in the output file and is protected
1273 if (gsym
->is_defined()
1274 && !gsym
->is_from_dynobj()
1275 && !gsym
->is_preemptible())
1277 target
->make_plt_entry(symtab
, layout
, gsym
);
1280 case elfcpp::R_386_GOTOFF
:
1281 case elfcpp::R_386_GOTPC
:
1282 // We need a GOT section.
1283 target
->got_section(symtab
, layout
);
1286 // These are relocations which should only be seen by the
1287 // dynamic linker, and should never be seen here.
1288 case elfcpp::R_386_COPY
:
1289 case elfcpp::R_386_GLOB_DAT
:
1290 case elfcpp::R_386_JUMP_SLOT
:
1291 case elfcpp::R_386_RELATIVE
:
1292 case elfcpp::R_386_TLS_TPOFF
:
1293 case elfcpp::R_386_TLS_DTPMOD32
:
1294 case elfcpp::R_386_TLS_DTPOFF32
:
1295 case elfcpp::R_386_TLS_TPOFF32
:
1296 case elfcpp::R_386_TLS_DESC
:
1297 gold_error(_("%s: unexpected reloc %u in object file"),
1298 object
->name().c_str(), r_type
);
1301 // These are initial tls relocs, which are expected when
1303 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1304 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1305 case elfcpp::R_386_TLS_DESC_CALL
:
1306 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1307 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1308 case elfcpp::R_386_TLS_IE
: // Initial-exec
1309 case elfcpp::R_386_TLS_IE_32
:
1310 case elfcpp::R_386_TLS_GOTIE
:
1311 case elfcpp::R_386_TLS_LE
: // Local-exec
1312 case elfcpp::R_386_TLS_LE_32
:
1314 const bool is_final
= gsym
->final_value_is_known();
1315 const tls::Tls_optimization optimized_type
1316 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1319 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1320 if (optimized_type
== tls::TLSOPT_NONE
)
1322 // Create a pair of GOT entries for the module index and
1323 // dtv-relative offset.
1324 Output_data_got
<32, false>* got
1325 = target
->got_section(symtab
, layout
);
1326 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1327 target
->rel_dyn_section(layout
),
1328 elfcpp::R_386_TLS_DTPMOD32
,
1329 elfcpp::R_386_TLS_DTPOFF32
);
1331 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1333 // Create a GOT entry for the tp-relative offset.
1334 Output_data_got
<32, false>* got
1335 = target
->got_section(symtab
, layout
);
1336 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1337 target
->rel_dyn_section(layout
),
1338 elfcpp::R_386_TLS_TPOFF
);
1340 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1341 unsupported_reloc_global(object
, r_type
, gsym
);
1344 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1345 target
->define_tls_base_symbol(symtab
, layout
);
1346 if (optimized_type
== tls::TLSOPT_NONE
)
1348 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1349 Output_data_got
<32, false>* got
1350 = target
->got_section(symtab
, layout
);
1351 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
,
1352 target
->rel_dyn_section(layout
),
1353 elfcpp::R_386_TLS_DESC
, 0);
1355 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1357 // Create a GOT entry for the tp-relative offset.
1358 Output_data_got
<32, false>* got
1359 = target
->got_section(symtab
, layout
);
1360 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1361 target
->rel_dyn_section(layout
),
1362 elfcpp::R_386_TLS_TPOFF
);
1364 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1365 unsupported_reloc_global(object
, r_type
, gsym
);
1368 case elfcpp::R_386_TLS_DESC_CALL
:
1371 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1372 if (optimized_type
== tls::TLSOPT_NONE
)
1374 // Create a GOT entry for the module index.
1375 target
->got_mod_index_entry(symtab
, layout
, object
);
1377 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1378 unsupported_reloc_global(object
, r_type
, gsym
);
1381 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1384 case elfcpp::R_386_TLS_IE
: // Initial-exec
1385 case elfcpp::R_386_TLS_IE_32
:
1386 case elfcpp::R_386_TLS_GOTIE
:
1387 layout
->set_has_static_tls();
1388 if (optimized_type
== tls::TLSOPT_NONE
)
1390 // For the R_386_TLS_IE relocation, we need to create a
1391 // dynamic relocation when building a shared library.
1392 if (r_type
== elfcpp::R_386_TLS_IE
1393 && parameters
->options().shared())
1395 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1396 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1397 output_section
, object
,
1399 reloc
.get_r_offset());
1401 // Create a GOT entry for the tp-relative offset.
1402 Output_data_got
<32, false>* got
1403 = target
->got_section(symtab
, layout
);
1404 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1405 ? elfcpp::R_386_TLS_TPOFF32
1406 : elfcpp::R_386_TLS_TPOFF
);
1407 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1408 ? GOT_TYPE_TLS_OFFSET
1409 : GOT_TYPE_TLS_NOFFSET
);
1410 got
->add_global_with_rel(gsym
, got_type
,
1411 target
->rel_dyn_section(layout
),
1414 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1415 unsupported_reloc_global(object
, r_type
, gsym
);
1418 case elfcpp::R_386_TLS_LE
: // Local-exec
1419 case elfcpp::R_386_TLS_LE_32
:
1420 layout
->set_has_static_tls();
1421 if (parameters
->options().shared())
1423 // We need to create a dynamic relocation.
1424 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1425 ? elfcpp::R_386_TLS_TPOFF32
1426 : elfcpp::R_386_TLS_TPOFF
);
1427 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1428 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1429 data_shndx
, reloc
.get_r_offset());
1439 case elfcpp::R_386_32PLT
:
1440 case elfcpp::R_386_TLS_GD_32
:
1441 case elfcpp::R_386_TLS_GD_PUSH
:
1442 case elfcpp::R_386_TLS_GD_CALL
:
1443 case elfcpp::R_386_TLS_GD_POP
:
1444 case elfcpp::R_386_TLS_LDM_32
:
1445 case elfcpp::R_386_TLS_LDM_PUSH
:
1446 case elfcpp::R_386_TLS_LDM_CALL
:
1447 case elfcpp::R_386_TLS_LDM_POP
:
1448 case elfcpp::R_386_USED_BY_INTEL_200
:
1450 unsupported_reloc_global(object
, r_type
, gsym
);
1455 // Scan relocations for a section.
1458 Target_i386::scan_relocs(const General_options
& options
,
1459 Symbol_table
* symtab
,
1461 Sized_relobj
<32, false>* object
,
1462 unsigned int data_shndx
,
1463 unsigned int sh_type
,
1464 const unsigned char* prelocs
,
1466 Output_section
* output_section
,
1467 bool needs_special_offset_handling
,
1468 size_t local_symbol_count
,
1469 const unsigned char* plocal_symbols
)
1471 if (sh_type
== elfcpp::SHT_RELA
)
1473 gold_error(_("%s: unsupported RELA reloc section"),
1474 object
->name().c_str());
1478 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1489 needs_special_offset_handling
,
1494 // Finalize the sections.
1497 Target_i386::do_finalize_sections(Layout
* layout
)
1499 // Fill in some more dynamic tags.
1500 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1503 if (this->got_plt_
!= NULL
)
1504 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1506 if (this->plt_
!= NULL
)
1508 const Output_data
* od
= this->plt_
->rel_plt();
1509 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1510 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1511 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
1514 if (this->rel_dyn_
!= NULL
)
1516 const Output_data
* od
= this->rel_dyn_
;
1517 odyn
->add_section_address(elfcpp::DT_REL
, od
);
1518 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
1519 odyn
->add_constant(elfcpp::DT_RELENT
,
1520 elfcpp::Elf_sizes
<32>::rel_size
);
1523 if (!parameters
->options().shared())
1525 // The value of the DT_DEBUG tag is filled in by the dynamic
1526 // linker at run time, and used by the debugger.
1527 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1531 // Emit any relocs we saved in an attempt to avoid generating COPY
1533 if (this->copy_relocs_
.any_saved_relocs())
1534 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1537 // Return whether a direct absolute static relocation needs to be applied.
1538 // In cases where Scan::local() or Scan::global() has created
1539 // a dynamic relocation other than R_386_RELATIVE, the addend
1540 // of the relocation is carried in the data, and we must not
1541 // apply the static relocation.
1544 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1548 // For local symbols, we will have created a non-RELATIVE dynamic
1549 // relocation only if (a) the output is position independent,
1550 // (b) the relocation is absolute (not pc- or segment-relative), and
1551 // (c) the relocation is not 32 bits wide.
1553 return !(parameters
->options().output_is_position_independent()
1554 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1557 // For global symbols, we use the same helper routines used in the
1558 // scan pass. If we did not create a dynamic relocation, or if we
1559 // created a RELATIVE dynamic relocation, we should apply the static
1561 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1562 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1563 && gsym
->can_use_relative_reloc(ref_flags
1564 & Symbol::FUNCTION_CALL
);
1565 return !has_dyn
|| is_rel
;
1568 // Perform a relocation.
1571 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1572 Target_i386
* target
,
1574 const elfcpp::Rel
<32, false>& rel
,
1575 unsigned int r_type
,
1576 const Sized_symbol
<32>* gsym
,
1577 const Symbol_value
<32>* psymval
,
1578 unsigned char* view
,
1579 elfcpp::Elf_types
<32>::Elf_Addr address
,
1580 section_size_type view_size
)
1582 if (this->skip_call_tls_get_addr_
)
1584 if (r_type
!= elfcpp::R_386_PLT32
1586 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1587 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1588 _("missing expected TLS relocation"));
1591 this->skip_call_tls_get_addr_
= false;
1596 // Pick the value to use for symbols defined in shared objects.
1597 Symbol_value
<32> symval
;
1598 bool is_nonpic
= (r_type
== elfcpp::R_386_PC8
1599 || r_type
== elfcpp::R_386_PC16
1600 || r_type
== elfcpp::R_386_PC32
);
1602 && (gsym
->is_from_dynobj()
1603 || (parameters
->options().shared()
1604 && (gsym
->is_undefined() || gsym
->is_preemptible())))
1605 && gsym
->has_plt_offset()
1606 && (!is_nonpic
|| !parameters
->options().shared()))
1608 symval
.set_output_value(target
->plt_section()->address()
1609 + gsym
->plt_offset());
1613 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1615 // Get the GOT offset if needed.
1616 // The GOT pointer points to the end of the GOT section.
1617 // We need to subtract the size of the GOT section to get
1618 // the actual offset to use in the relocation.
1619 bool have_got_offset
= false;
1620 unsigned int got_offset
= 0;
1623 case elfcpp::R_386_GOT32
:
1626 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1627 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1628 - target
->got_size());
1632 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1633 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1634 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1635 - target
->got_size());
1637 have_got_offset
= true;
1646 case elfcpp::R_386_NONE
:
1647 case elfcpp::R_386_GNU_VTINHERIT
:
1648 case elfcpp::R_386_GNU_VTENTRY
:
1651 case elfcpp::R_386_32
:
1652 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true))
1653 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1656 case elfcpp::R_386_PC32
:
1658 int ref_flags
= Symbol::NON_PIC_REF
;
1659 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1660 ref_flags
|= Symbol::FUNCTION_CALL
;
1661 if (should_apply_static_reloc(gsym
, ref_flags
, true))
1662 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1666 case elfcpp::R_386_16
:
1667 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1668 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1671 case elfcpp::R_386_PC16
:
1673 int ref_flags
= Symbol::NON_PIC_REF
;
1674 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1675 ref_flags
|= Symbol::FUNCTION_CALL
;
1676 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1677 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1681 case elfcpp::R_386_8
:
1682 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1683 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1686 case elfcpp::R_386_PC8
:
1688 int ref_flags
= Symbol::NON_PIC_REF
;
1689 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1690 ref_flags
|= Symbol::FUNCTION_CALL
;
1691 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1692 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1696 case elfcpp::R_386_PLT32
:
1697 gold_assert(gsym
== NULL
1698 || gsym
->has_plt_offset()
1699 || gsym
->final_value_is_known()
1700 || (gsym
->is_defined()
1701 && !gsym
->is_from_dynobj()
1702 && !gsym
->is_preemptible()));
1703 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1706 case elfcpp::R_386_GOT32
:
1707 gold_assert(have_got_offset
);
1708 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1711 case elfcpp::R_386_GOTOFF
:
1713 elfcpp::Elf_types
<32>::Elf_Addr value
;
1714 value
= (psymval
->value(object
, 0)
1715 - target
->got_plt_section()->address());
1716 Relocate_functions
<32, false>::rel32(view
, value
);
1720 case elfcpp::R_386_GOTPC
:
1722 elfcpp::Elf_types
<32>::Elf_Addr value
;
1723 value
= target
->got_plt_section()->address();
1724 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1728 case elfcpp::R_386_COPY
:
1729 case elfcpp::R_386_GLOB_DAT
:
1730 case elfcpp::R_386_JUMP_SLOT
:
1731 case elfcpp::R_386_RELATIVE
:
1732 // These are outstanding tls relocs, which are unexpected when
1734 case elfcpp::R_386_TLS_TPOFF
:
1735 case elfcpp::R_386_TLS_DTPMOD32
:
1736 case elfcpp::R_386_TLS_DTPOFF32
:
1737 case elfcpp::R_386_TLS_TPOFF32
:
1738 case elfcpp::R_386_TLS_DESC
:
1739 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1740 _("unexpected reloc %u in object file"),
1744 // These are initial tls relocs, which are expected when
1746 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1747 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1748 case elfcpp::R_386_TLS_DESC_CALL
:
1749 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1750 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1751 case elfcpp::R_386_TLS_IE
: // Initial-exec
1752 case elfcpp::R_386_TLS_IE_32
:
1753 case elfcpp::R_386_TLS_GOTIE
:
1754 case elfcpp::R_386_TLS_LE
: // Local-exec
1755 case elfcpp::R_386_TLS_LE_32
:
1756 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1757 view
, address
, view_size
);
1760 case elfcpp::R_386_32PLT
:
1761 case elfcpp::R_386_TLS_GD_32
:
1762 case elfcpp::R_386_TLS_GD_PUSH
:
1763 case elfcpp::R_386_TLS_GD_CALL
:
1764 case elfcpp::R_386_TLS_GD_POP
:
1765 case elfcpp::R_386_TLS_LDM_32
:
1766 case elfcpp::R_386_TLS_LDM_PUSH
:
1767 case elfcpp::R_386_TLS_LDM_CALL
:
1768 case elfcpp::R_386_TLS_LDM_POP
:
1769 case elfcpp::R_386_USED_BY_INTEL_200
:
1771 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1772 _("unsupported reloc %u"),
1780 // Perform a TLS relocation.
1783 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1784 Target_i386
* target
,
1786 const elfcpp::Rel
<32, false>& rel
,
1787 unsigned int r_type
,
1788 const Sized_symbol
<32>* gsym
,
1789 const Symbol_value
<32>* psymval
,
1790 unsigned char* view
,
1791 elfcpp::Elf_types
<32>::Elf_Addr
,
1792 section_size_type view_size
)
1794 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1796 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1798 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1800 const bool is_final
=
1802 ? !parameters
->options().output_is_position_independent()
1803 : gsym
->final_value_is_known());
1804 const tls::Tls_optimization optimized_type
1805 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1808 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1809 if (optimized_type
== tls::TLSOPT_TO_LE
)
1811 gold_assert(tls_segment
!= NULL
);
1812 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1813 rel
, r_type
, value
, view
,
1819 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1820 ? GOT_TYPE_TLS_NOFFSET
1821 : GOT_TYPE_TLS_PAIR
);
1822 unsigned int got_offset
;
1825 gold_assert(gsym
->has_got_offset(got_type
));
1826 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1830 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1831 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1832 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1833 - target
->got_size());
1835 if (optimized_type
== tls::TLSOPT_TO_IE
)
1837 gold_assert(tls_segment
!= NULL
);
1838 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1839 got_offset
, view
, view_size
);
1842 else if (optimized_type
== tls::TLSOPT_NONE
)
1844 // Relocate the field with the offset of the pair of GOT
1846 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1850 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1851 _("unsupported reloc %u"),
1855 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1856 case elfcpp::R_386_TLS_DESC_CALL
:
1857 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1858 if (optimized_type
== tls::TLSOPT_TO_LE
)
1860 gold_assert(tls_segment
!= NULL
);
1861 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
1862 rel
, r_type
, value
, view
,
1868 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1869 ? GOT_TYPE_TLS_NOFFSET
1870 : GOT_TYPE_TLS_DESC
);
1871 unsigned int got_offset
;
1874 gold_assert(gsym
->has_got_offset(got_type
));
1875 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1879 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1880 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1881 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1882 - target
->got_size());
1884 if (optimized_type
== tls::TLSOPT_TO_IE
)
1886 gold_assert(tls_segment
!= NULL
);
1887 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1888 got_offset
, view
, view_size
);
1891 else if (optimized_type
== tls::TLSOPT_NONE
)
1893 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
1895 // Relocate the field with the offset of the pair of GOT
1897 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1902 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1903 _("unsupported reloc %u"),
1907 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1908 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
1910 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1911 _("both SUN and GNU model "
1912 "TLS relocations"));
1915 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1916 if (optimized_type
== tls::TLSOPT_TO_LE
)
1918 gold_assert(tls_segment
!= NULL
);
1919 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1920 value
, view
, view_size
);
1923 else if (optimized_type
== tls::TLSOPT_NONE
)
1925 // Relocate the field with the offset of the GOT entry for
1926 // the module index.
1927 unsigned int got_offset
;
1928 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
1929 - target
->got_size());
1930 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1933 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1934 _("unsupported reloc %u"),
1938 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1939 // This reloc can appear in debugging sections, in which case we
1940 // won't see the TLS_LDM reloc. The local_dynamic_type field
1942 if (optimized_type
== tls::TLSOPT_TO_LE
1943 && this->local_dynamic_type_
!= LOCAL_DYNAMIC_NONE
)
1945 gold_assert(tls_segment
!= NULL
);
1946 value
-= tls_segment
->memsz();
1948 Relocate_functions
<32, false>::rel32(view
, value
);
1951 case elfcpp::R_386_TLS_IE
: // Initial-exec
1952 case elfcpp::R_386_TLS_GOTIE
:
1953 case elfcpp::R_386_TLS_IE_32
:
1954 if (optimized_type
== tls::TLSOPT_TO_LE
)
1956 gold_assert(tls_segment
!= NULL
);
1957 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1958 rel
, r_type
, value
, view
,
1962 else if (optimized_type
== tls::TLSOPT_NONE
)
1964 // Relocate the field with the offset of the GOT entry for
1965 // the tp-relative offset of the symbol.
1966 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1967 ? GOT_TYPE_TLS_OFFSET
1968 : GOT_TYPE_TLS_NOFFSET
);
1969 unsigned int got_offset
;
1972 gold_assert(gsym
->has_got_offset(got_type
));
1973 got_offset
= gsym
->got_offset(got_type
);
1977 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1978 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1979 got_offset
= object
->local_got_offset(r_sym
, got_type
);
1981 // For the R_386_TLS_IE relocation, we need to apply the
1982 // absolute address of the GOT entry.
1983 if (r_type
== elfcpp::R_386_TLS_IE
)
1984 got_offset
+= target
->got_plt_section()->address();
1985 // All GOT offsets are relative to the end of the GOT.
1986 got_offset
-= target
->got_size();
1987 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1990 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1991 _("unsupported reloc %u"),
1995 case elfcpp::R_386_TLS_LE
: // Local-exec
1996 // If we're creating a shared library, a dynamic relocation will
1997 // have been created for this location, so do not apply it now.
1998 if (!parameters
->options().shared())
2000 gold_assert(tls_segment
!= NULL
);
2001 value
-= tls_segment
->memsz();
2002 Relocate_functions
<32, false>::rel32(view
, value
);
2006 case elfcpp::R_386_TLS_LE_32
:
2007 // If we're creating a shared library, a dynamic relocation will
2008 // have been created for this location, so do not apply it now.
2009 if (!parameters
->options().shared())
2011 gold_assert(tls_segment
!= NULL
);
2012 value
= tls_segment
->memsz() - value
;
2013 Relocate_functions
<32, false>::rel32(view
, value
);
2019 // Do a relocation in which we convert a TLS General-Dynamic to a
2023 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2025 Output_segment
* tls_segment
,
2026 const elfcpp::Rel
<32, false>& rel
,
2028 elfcpp::Elf_types
<32>::Elf_Addr value
,
2029 unsigned char* view
,
2030 section_size_type view_size
)
2032 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2033 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2034 // leal foo(%reg),%eax; call ___tls_get_addr
2035 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2037 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2038 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2040 unsigned char op1
= view
[-1];
2041 unsigned char op2
= view
[-2];
2043 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2044 op2
== 0x8d || op2
== 0x04);
2045 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2051 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2052 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2053 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2054 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2055 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2059 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2060 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2061 if (rel
.get_r_offset() + 9 < view_size
2064 // There is a trailing nop. Use the size byte subl.
2065 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2070 // Use the five byte subl.
2071 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2075 value
= tls_segment
->memsz() - value
;
2076 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
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 General-Dynamic to an
2087 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2090 const elfcpp::Rel
<32, false>& rel
,
2092 elfcpp::Elf_types
<32>::Elf_Addr value
,
2093 unsigned char* view
,
2094 section_size_type view_size
)
2096 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2097 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2099 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2100 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2102 unsigned char op1
= view
[-1];
2103 unsigned char op2
= view
[-2];
2105 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2106 op2
== 0x8d || op2
== 0x04);
2107 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2111 // FIXME: For now, support only the first (SIB) form.
2112 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2116 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2117 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2118 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2119 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2120 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2124 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2125 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2126 if (rel
.get_r_offset() + 9 < view_size
2129 // FIXME: This is not the right instruction sequence.
2130 // There is a trailing nop. Use the size byte subl.
2131 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2136 // FIXME: This is not the right instruction sequence.
2137 // Use the five byte subl.
2138 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2142 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2144 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2146 this->skip_call_tls_get_addr_
= true;
2149 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2150 // General-Dynamic to a Local-Exec.
2153 Target_i386::Relocate::tls_desc_gd_to_le(
2154 const Relocate_info
<32, false>* relinfo
,
2156 Output_segment
* tls_segment
,
2157 const elfcpp::Rel
<32, false>& rel
,
2158 unsigned int r_type
,
2159 elfcpp::Elf_types
<32>::Elf_Addr value
,
2160 unsigned char* view
,
2161 section_size_type view_size
)
2163 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2165 // leal foo@TLSDESC(%ebx), %eax
2166 // ==> leal foo@NTPOFF, %eax
2167 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2168 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2169 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2170 view
[-2] == 0x8d && view
[-1] == 0x83);
2172 value
-= tls_segment
->memsz();
2173 Relocate_functions
<32, false>::rel32(view
, value
);
2177 // call *foo@TLSCALL(%eax)
2179 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2180 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2181 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2182 view
[0] == 0xff && view
[1] == 0x10);
2188 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2189 // General-Dynamic to an Initial-Exec.
2192 Target_i386::Relocate::tls_desc_gd_to_ie(
2193 const Relocate_info
<32, false>* relinfo
,
2196 const elfcpp::Rel
<32, false>& rel
,
2197 unsigned int r_type
,
2198 elfcpp::Elf_types
<32>::Elf_Addr value
,
2199 unsigned char* view
,
2200 section_size_type view_size
)
2202 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2204 // leal foo@TLSDESC(%ebx), %eax
2205 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2206 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2207 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2208 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2209 view
[-2] == 0x8d && view
[-1] == 0x83);
2211 Relocate_functions
<32, false>::rel32(view
, value
);
2215 // call *foo@TLSCALL(%eax)
2217 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2218 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2219 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2220 view
[0] == 0xff && view
[1] == 0x10);
2226 // Do a relocation in which we convert a TLS Local-Dynamic to a
2230 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2233 const elfcpp::Rel
<32, false>& rel
,
2235 elfcpp::Elf_types
<32>::Elf_Addr
,
2236 unsigned char* view
,
2237 section_size_type view_size
)
2239 // leal foo(%reg), %eax; call ___tls_get_addr
2240 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2242 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2243 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2245 // FIXME: Does this test really always pass?
2246 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2247 view
[-2] == 0x8d && view
[-1] == 0x83);
2249 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2251 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2253 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2255 this->skip_call_tls_get_addr_
= true;
2258 // Do a relocation in which we convert a TLS Initial-Exec to a
2262 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2264 Output_segment
* tls_segment
,
2265 const elfcpp::Rel
<32, false>& rel
,
2266 unsigned int r_type
,
2267 elfcpp::Elf_types
<32>::Elf_Addr value
,
2268 unsigned char* view
,
2269 section_size_type view_size
)
2271 // We have to actually change the instructions, which means that we
2272 // need to examine the opcodes to figure out which instruction we
2274 if (r_type
== elfcpp::R_386_TLS_IE
)
2276 // movl %gs:XX,%eax ==> movl $YY,%eax
2277 // movl %gs:XX,%reg ==> movl $YY,%reg
2278 // addl %gs:XX,%reg ==> addl $YY,%reg
2279 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2280 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2282 unsigned char op1
= view
[-1];
2285 // movl XX,%eax ==> movl $YY,%eax
2290 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2292 unsigned char op2
= view
[-2];
2295 // movl XX,%reg ==> movl $YY,%reg
2296 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2297 (op1
& 0xc7) == 0x05);
2299 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2301 else if (op2
== 0x03)
2303 // addl XX,%reg ==> addl $YY,%reg
2304 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2305 (op1
& 0xc7) == 0x05);
2307 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2310 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2315 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2316 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2317 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2318 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2319 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2321 unsigned char op1
= view
[-1];
2322 unsigned char op2
= view
[-2];
2323 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2324 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2327 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2329 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2331 else if (op2
== 0x2b)
2333 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2335 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2337 else if (op2
== 0x03)
2339 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2341 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2344 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2347 value
= tls_segment
->memsz() - value
;
2348 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2351 Relocate_functions
<32, false>::rel32(view
, value
);
2354 // Relocate section data.
2357 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2358 unsigned int sh_type
,
2359 const unsigned char* prelocs
,
2361 Output_section
* output_section
,
2362 bool needs_special_offset_handling
,
2363 unsigned char* view
,
2364 elfcpp::Elf_types
<32>::Elf_Addr address
,
2365 section_size_type view_size
)
2367 gold_assert(sh_type
== elfcpp::SHT_REL
);
2369 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2370 Target_i386::Relocate
>(
2376 needs_special_offset_handling
,
2382 // Return the size of a relocation while scanning during a relocatable
2386 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2387 unsigned int r_type
,
2392 case elfcpp::R_386_NONE
:
2393 case elfcpp::R_386_GNU_VTINHERIT
:
2394 case elfcpp::R_386_GNU_VTENTRY
:
2395 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2396 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2397 case elfcpp::R_386_TLS_DESC_CALL
:
2398 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2399 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2400 case elfcpp::R_386_TLS_IE
: // Initial-exec
2401 case elfcpp::R_386_TLS_IE_32
:
2402 case elfcpp::R_386_TLS_GOTIE
:
2403 case elfcpp::R_386_TLS_LE
: // Local-exec
2404 case elfcpp::R_386_TLS_LE_32
:
2407 case elfcpp::R_386_32
:
2408 case elfcpp::R_386_PC32
:
2409 case elfcpp::R_386_GOT32
:
2410 case elfcpp::R_386_PLT32
:
2411 case elfcpp::R_386_GOTOFF
:
2412 case elfcpp::R_386_GOTPC
:
2415 case elfcpp::R_386_16
:
2416 case elfcpp::R_386_PC16
:
2419 case elfcpp::R_386_8
:
2420 case elfcpp::R_386_PC8
:
2423 // These are relocations which should only be seen by the
2424 // dynamic linker, and should never be seen here.
2425 case elfcpp::R_386_COPY
:
2426 case elfcpp::R_386_GLOB_DAT
:
2427 case elfcpp::R_386_JUMP_SLOT
:
2428 case elfcpp::R_386_RELATIVE
:
2429 case elfcpp::R_386_TLS_TPOFF
:
2430 case elfcpp::R_386_TLS_DTPMOD32
:
2431 case elfcpp::R_386_TLS_DTPOFF32
:
2432 case elfcpp::R_386_TLS_TPOFF32
:
2433 case elfcpp::R_386_TLS_DESC
:
2434 object
->error(_("unexpected reloc %u in object file"), r_type
);
2437 case elfcpp::R_386_32PLT
:
2438 case elfcpp::R_386_TLS_GD_32
:
2439 case elfcpp::R_386_TLS_GD_PUSH
:
2440 case elfcpp::R_386_TLS_GD_CALL
:
2441 case elfcpp::R_386_TLS_GD_POP
:
2442 case elfcpp::R_386_TLS_LDM_32
:
2443 case elfcpp::R_386_TLS_LDM_PUSH
:
2444 case elfcpp::R_386_TLS_LDM_CALL
:
2445 case elfcpp::R_386_TLS_LDM_POP
:
2446 case elfcpp::R_386_USED_BY_INTEL_200
:
2448 object
->error(_("unsupported reloc %u in object file"), r_type
);
2453 // Scan the relocs during a relocatable link.
2456 Target_i386::scan_relocatable_relocs(const General_options
& options
,
2457 Symbol_table
* symtab
,
2459 Sized_relobj
<32, false>* object
,
2460 unsigned int data_shndx
,
2461 unsigned int sh_type
,
2462 const unsigned char* prelocs
,
2464 Output_section
* output_section
,
2465 bool needs_special_offset_handling
,
2466 size_t local_symbol_count
,
2467 const unsigned char* plocal_symbols
,
2468 Relocatable_relocs
* rr
)
2470 gold_assert(sh_type
== elfcpp::SHT_REL
);
2472 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2473 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2475 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2476 Scan_relocatable_relocs
>(
2485 needs_special_offset_handling
,
2491 // Relocate a section during a relocatable link.
2494 Target_i386::relocate_for_relocatable(
2495 const Relocate_info
<32, false>* relinfo
,
2496 unsigned int sh_type
,
2497 const unsigned char* prelocs
,
2499 Output_section
* output_section
,
2500 off_t offset_in_output_section
,
2501 const Relocatable_relocs
* rr
,
2502 unsigned char* view
,
2503 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2504 section_size_type view_size
,
2505 unsigned char* reloc_view
,
2506 section_size_type reloc_view_size
)
2508 gold_assert(sh_type
== elfcpp::SHT_REL
);
2510 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2515 offset_in_output_section
,
2524 // Return the value to use for a dynamic which requires special
2525 // treatment. This is how we support equality comparisons of function
2526 // pointers across shared library boundaries, as described in the
2527 // processor specific ABI supplement.
2530 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2532 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2533 return this->plt_section()->address() + gsym
->plt_offset();
2536 // Return a string used to fill a code section with nops to take up
2537 // the specified length.
2540 Target_i386::do_code_fill(section_size_type length
) const
2544 // Build a jmp instruction to skip over the bytes.
2545 unsigned char jmp
[5];
2547 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2548 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2549 + std::string(length
- 5, '\0'));
2552 // Nop sequences of various lengths.
2553 const char nop1
[1] = { 0x90 }; // nop
2554 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2555 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2556 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2557 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2558 0x00 }; // leal 0(%esi,1),%esi
2559 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2561 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2563 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2564 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2565 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2566 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2568 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2569 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2571 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2572 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2574 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2575 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2576 0x00, 0x00, 0x00, 0x00 };
2577 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2578 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2579 0x27, 0x00, 0x00, 0x00,
2581 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2582 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2583 0xbc, 0x27, 0x00, 0x00,
2585 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2586 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2587 0x90, 0x90, 0x90, 0x90,
2590 const char* nops
[16] = {
2592 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2593 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2596 return std::string(nops
[length
], length
);
2599 // The selector for i386 object files.
2601 class Target_selector_i386
: public Target_selector
2604 Target_selector_i386()
2605 : Target_selector(elfcpp::EM_386
, 32, false, "elf32-i386")
2609 do_instantiate_target()
2610 { return new Target_i386(); }
2613 Target_selector_i386 target_selector_i386
;
2615 } // End anonymous namespace.