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
, Relobj
* object
,
361 unsigned int shndx
, Output_section
* output_section
,
362 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
364 this->copy_relocs_
.copy_reloc(symtab
, layout
,
365 symtab
->get_sized_symbol
<32>(sym
),
366 object
, shndx
, output_section
, reloc
,
367 this->rel_dyn_section(layout
));
370 // Information about this specific target which we pass to the
371 // general Target structure.
372 static const Target::Target_info i386_info
;
374 // The types of GOT entries needed for this platform.
377 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
378 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
379 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
380 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
381 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
385 Output_data_got
<32, false>* got_
;
387 Output_data_plt_i386
* plt_
;
388 // The GOT PLT section.
389 Output_data_space
* got_plt_
;
390 // The dynamic reloc section.
391 Reloc_section
* rel_dyn_
;
392 // Relocs saved to avoid a COPY reloc.
393 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
394 // Space for variables copied with a COPY reloc.
395 Output_data_space
* dynbss_
;
396 // Offset of the GOT entry for the TLS module index.
397 unsigned int got_mod_index_offset_
;
398 // True if the _TLS_MODULE_BASE_ symbol has been defined.
399 bool tls_base_symbol_defined_
;
402 const Target::Target_info
Target_i386::i386_info
=
405 false, // is_big_endian
406 elfcpp::EM_386
, // machine_code
407 false, // has_make_symbol
408 false, // has_resolve
409 true, // has_code_fill
410 true, // is_default_stack_executable
412 "/usr/lib/libc.so.1", // dynamic_linker
413 0x08048000, // default_text_segment_address
414 0x1000, // abi_pagesize (overridable by -z max-page-size)
415 0x1000 // common_pagesize (overridable by -z common-page-size)
418 // Get the GOT section, creating it if necessary.
420 Output_data_got
<32, false>*
421 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
423 if (this->got_
== NULL
)
425 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
427 this->got_
= new Output_data_got
<32, false>();
430 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
432 | elfcpp::SHF_WRITE
),
436 // The old GNU linker creates a .got.plt section. We just
437 // create another set of data in the .got section. Note that we
438 // always create a PLT if we create a GOT, although the PLT
440 this->got_plt_
= new Output_data_space(4);
441 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
443 | elfcpp::SHF_WRITE
),
447 // The first three entries are reserved.
448 this->got_plt_
->set_current_data_size(3 * 4);
450 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
451 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
453 0, 0, elfcpp::STT_OBJECT
,
455 elfcpp::STV_HIDDEN
, 0,
462 // Get the dynamic reloc section, creating it if necessary.
464 Target_i386::Reloc_section
*
465 Target_i386::rel_dyn_section(Layout
* layout
)
467 if (this->rel_dyn_
== NULL
)
469 gold_assert(layout
!= NULL
);
470 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
471 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
472 elfcpp::SHF_ALLOC
, this->rel_dyn_
);
474 return this->rel_dyn_
;
477 // A class to handle the PLT data.
479 class Output_data_plt_i386
: public Output_section_data
482 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
484 Output_data_plt_i386(Layout
*, Output_data_space
*);
486 // Add an entry to the PLT.
488 add_entry(Symbol
* gsym
);
490 // Return the .rel.plt section data.
493 { return this->rel_
; }
497 do_adjust_output_section(Output_section
* os
);
500 // The size of an entry in the PLT.
501 static const int plt_entry_size
= 16;
503 // The first entry in the PLT for an executable.
504 static unsigned char exec_first_plt_entry
[plt_entry_size
];
506 // The first entry in the PLT for a shared object.
507 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
509 // Other entries in the PLT for an executable.
510 static unsigned char exec_plt_entry
[plt_entry_size
];
512 // Other entries in the PLT for a shared object.
513 static unsigned char dyn_plt_entry
[plt_entry_size
];
515 // Set the final size.
517 set_final_data_size()
518 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
520 // Write out the PLT data.
522 do_write(Output_file
*);
524 // The reloc section.
526 // The .got.plt section.
527 Output_data_space
* got_plt_
;
528 // The number of PLT entries.
532 // Create the PLT section. The ordinary .got section is an argument,
533 // since we need to refer to the start. We also create our own .got
534 // section just for PLT entries.
536 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
537 Output_data_space
* got_plt
)
538 : Output_section_data(4), got_plt_(got_plt
), count_(0)
540 this->rel_
= new Reloc_section(false);
541 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
542 elfcpp::SHF_ALLOC
, this->rel_
);
546 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
548 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
549 // linker, and so do we.
553 // Add an entry to the PLT.
556 Output_data_plt_i386::add_entry(Symbol
* gsym
)
558 gold_assert(!gsym
->has_plt_offset());
560 // Note that when setting the PLT offset we skip the initial
561 // reserved PLT entry.
562 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
566 section_offset_type got_offset
= this->got_plt_
->current_data_size();
568 // Every PLT entry needs a GOT entry which points back to the PLT
569 // entry (this will be changed by the dynamic linker, normally
570 // lazily when the function is called).
571 this->got_plt_
->set_current_data_size(got_offset
+ 4);
573 // Every PLT entry needs a reloc.
574 gsym
->set_needs_dynsym_entry();
575 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
578 // Note that we don't need to save the symbol. The contents of the
579 // PLT are independent of which symbols are used. The symbols only
580 // appear in the relocations.
583 // The first entry in the PLT for an executable.
585 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
587 0xff, 0x35, // pushl contents of memory address
588 0, 0, 0, 0, // replaced with address of .got + 4
589 0xff, 0x25, // jmp indirect
590 0, 0, 0, 0, // replaced with address of .got + 8
594 // The first entry in the PLT for a shared object.
596 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
598 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
599 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
603 // Subsequent entries in the PLT for an executable.
605 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
607 0xff, 0x25, // jmp indirect
608 0, 0, 0, 0, // replaced with address of symbol in .got
609 0x68, // pushl immediate
610 0, 0, 0, 0, // replaced with offset into relocation table
611 0xe9, // jmp relative
612 0, 0, 0, 0 // replaced with offset to start of .plt
615 // Subsequent entries in the PLT for a shared object.
617 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
619 0xff, 0xa3, // jmp *offset(%ebx)
620 0, 0, 0, 0, // replaced with offset of symbol in .got
621 0x68, // pushl immediate
622 0, 0, 0, 0, // replaced with offset into relocation table
623 0xe9, // jmp relative
624 0, 0, 0, 0 // replaced with offset to start of .plt
627 // Write out the PLT. This uses the hand-coded instructions above,
628 // and adjusts them as needed. This is all specified by the i386 ELF
629 // Processor Supplement.
632 Output_data_plt_i386::do_write(Output_file
* of
)
634 const off_t offset
= this->offset();
635 const section_size_type oview_size
=
636 convert_to_section_size_type(this->data_size());
637 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
639 const off_t got_file_offset
= this->got_plt_
->offset();
640 const section_size_type got_size
=
641 convert_to_section_size_type(this->got_plt_
->data_size());
642 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
645 unsigned char* pov
= oview
;
647 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
648 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
650 if (parameters
->options().shared())
651 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
654 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
655 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
656 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
658 pov
+= plt_entry_size
;
660 unsigned char* got_pov
= got_view
;
662 memset(got_pov
, 0, 12);
665 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
667 unsigned int plt_offset
= plt_entry_size
;
668 unsigned int plt_rel_offset
= 0;
669 unsigned int got_offset
= 12;
670 const unsigned int count
= this->count_
;
671 for (unsigned int i
= 0;
674 pov
+= plt_entry_size
,
676 plt_offset
+= plt_entry_size
,
677 plt_rel_offset
+= rel_size
,
680 // Set and adjust the PLT entry itself.
682 if (parameters
->options().shared())
684 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
685 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
689 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
690 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
695 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
696 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
697 - (plt_offset
+ plt_entry_size
));
699 // Set the entry in the GOT.
700 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
703 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
704 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
706 of
->write_output_view(offset
, oview_size
, oview
);
707 of
->write_output_view(got_file_offset
, got_size
, got_view
);
710 // Create a PLT entry for a global symbol.
713 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
715 if (gsym
->has_plt_offset())
718 if (this->plt_
== NULL
)
720 // Create the GOT sections first.
721 this->got_section(symtab
, layout
);
723 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
724 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
726 | elfcpp::SHF_EXECINSTR
),
730 this->plt_
->add_entry(gsym
);
733 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
736 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
738 if (this->tls_base_symbol_defined_
)
741 Output_segment
* tls_segment
= layout
->tls_segment();
742 if (tls_segment
!= NULL
)
744 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
748 elfcpp::STV_HIDDEN
, 0,
749 Symbol::SEGMENT_END
, true);
751 this->tls_base_symbol_defined_
= true;
754 // Create a GOT entry for the TLS module index.
757 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
758 Sized_relobj
<32, false>* object
)
760 if (this->got_mod_index_offset_
== -1U)
762 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
763 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
764 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
765 unsigned int got_offset
= got
->add_constant(0);
766 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
768 got
->add_constant(0);
769 this->got_mod_index_offset_
= got_offset
;
771 return this->got_mod_index_offset_
;
774 // Optimize the TLS relocation type based on what we know about the
775 // symbol. IS_FINAL is true if the final address of this symbol is
776 // known at link time.
778 tls::Tls_optimization
779 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
781 // If we are generating a shared library, then we can't do anything
783 if (parameters
->options().shared())
784 return tls::TLSOPT_NONE
;
788 case elfcpp::R_386_TLS_GD
:
789 case elfcpp::R_386_TLS_GOTDESC
:
790 case elfcpp::R_386_TLS_DESC_CALL
:
791 // These are General-Dynamic which permits fully general TLS
792 // access. Since we know that we are generating an executable,
793 // we can convert this to Initial-Exec. If we also know that
794 // this is a local symbol, we can further switch to Local-Exec.
796 return tls::TLSOPT_TO_LE
;
797 return tls::TLSOPT_TO_IE
;
799 case elfcpp::R_386_TLS_LDM
:
800 // This is Local-Dynamic, which refers to a local symbol in the
801 // dynamic TLS block. Since we know that we generating an
802 // executable, we can switch to Local-Exec.
803 return tls::TLSOPT_TO_LE
;
805 case elfcpp::R_386_TLS_LDO_32
:
806 // Another type of Local-Dynamic relocation.
807 return tls::TLSOPT_TO_LE
;
809 case elfcpp::R_386_TLS_IE
:
810 case elfcpp::R_386_TLS_GOTIE
:
811 case elfcpp::R_386_TLS_IE_32
:
812 // These are Initial-Exec relocs which get the thread offset
813 // from the GOT. If we know that we are linking against the
814 // local symbol, we can switch to Local-Exec, which links the
815 // thread offset into the instruction.
817 return tls::TLSOPT_TO_LE
;
818 return tls::TLSOPT_NONE
;
820 case elfcpp::R_386_TLS_LE
:
821 case elfcpp::R_386_TLS_LE_32
:
822 // When we already have Local-Exec, there is nothing further we
824 return tls::TLSOPT_NONE
;
831 // Report an unsupported relocation against a local symbol.
834 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
837 gold_error(_("%s: unsupported reloc %u against local symbol"),
838 object
->name().c_str(), r_type
);
841 // Scan a relocation for a local symbol.
844 Target_i386::Scan::local(const General_options
&,
845 Symbol_table
* symtab
,
848 Sized_relobj
<32, false>* object
,
849 unsigned int data_shndx
,
850 Output_section
* output_section
,
851 const elfcpp::Rel
<32, false>& reloc
,
853 const elfcpp::Sym
<32, false>& lsym
)
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 // If building a shared library (or a position-independent
864 // executable), we need to create a dynamic relocation for
865 // this location. The relocation applied at link time will
866 // apply the link-time value, so we flag the location with
867 // an R_386_RELATIVE relocation so the dynamic loader can
868 // relocate it easily.
869 if (parameters
->options().output_is_position_independent())
871 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
872 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
873 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
874 output_section
, data_shndx
,
875 reloc
.get_r_offset());
879 case elfcpp::R_386_16
:
880 case elfcpp::R_386_8
:
881 // If building a shared library (or a position-independent
882 // executable), we need to create a dynamic relocation for
883 // this location. Because the addend needs to remain in the
884 // data section, we need to be careful not to apply this
885 // relocation statically.
886 if (parameters
->options().output_is_position_independent())
888 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
889 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
890 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
891 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
892 data_shndx
, reloc
.get_r_offset());
895 gold_assert(lsym
.get_st_value() == 0);
896 unsigned int shndx
= lsym
.get_st_shndx();
898 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
901 object
->error(_("section symbol %u has bad shndx %u"),
904 rel_dyn
->add_local_section(object
, shndx
,
905 r_type
, output_section
,
906 data_shndx
, reloc
.get_r_offset());
911 case elfcpp::R_386_PC32
:
912 case elfcpp::R_386_PC16
:
913 case elfcpp::R_386_PC8
:
916 case elfcpp::R_386_PLT32
:
917 // Since we know this is a local symbol, we can handle this as a
921 case elfcpp::R_386_GOTOFF
:
922 case elfcpp::R_386_GOTPC
:
923 // We need a GOT section.
924 target
->got_section(symtab
, layout
);
927 case elfcpp::R_386_GOT32
:
929 // The symbol requires a GOT entry.
930 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
931 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
932 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
934 // If we are generating a shared object, we need to add a
935 // dynamic RELATIVE relocation for this symbol's GOT entry.
936 if (parameters
->options().output_is_position_independent())
938 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
939 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
940 rel_dyn
->add_local_relative(
941 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
942 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
948 // These are relocations which should only be seen by the
949 // dynamic linker, and should never be seen here.
950 case elfcpp::R_386_COPY
:
951 case elfcpp::R_386_GLOB_DAT
:
952 case elfcpp::R_386_JUMP_SLOT
:
953 case elfcpp::R_386_RELATIVE
:
954 case elfcpp::R_386_TLS_TPOFF
:
955 case elfcpp::R_386_TLS_DTPMOD32
:
956 case elfcpp::R_386_TLS_DTPOFF32
:
957 case elfcpp::R_386_TLS_TPOFF32
:
958 case elfcpp::R_386_TLS_DESC
:
959 gold_error(_("%s: unexpected reloc %u in object file"),
960 object
->name().c_str(), r_type
);
963 // These are initial TLS relocs, which are expected when
965 case elfcpp::R_386_TLS_GD
: // Global-dynamic
966 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
967 case elfcpp::R_386_TLS_DESC_CALL
:
968 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
969 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
970 case elfcpp::R_386_TLS_IE
: // Initial-exec
971 case elfcpp::R_386_TLS_IE_32
:
972 case elfcpp::R_386_TLS_GOTIE
:
973 case elfcpp::R_386_TLS_LE
: // Local-exec
974 case elfcpp::R_386_TLS_LE_32
:
976 bool output_is_shared
= parameters
->options().shared();
977 const tls::Tls_optimization optimized_type
978 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
981 case elfcpp::R_386_TLS_GD
: // Global-dynamic
982 if (optimized_type
== tls::TLSOPT_NONE
)
984 // Create a pair of GOT entries for the module index and
985 // dtv-relative offset.
986 Output_data_got
<32, false>* got
987 = target
->got_section(symtab
, layout
);
988 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
989 unsigned int shndx
= lsym
.get_st_shndx();
991 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
993 object
->error(_("local symbol %u has bad shndx %u"),
996 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
998 target
->rel_dyn_section(layout
),
999 elfcpp::R_386_TLS_DTPMOD32
, 0);
1001 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1002 unsupported_reloc_local(object
, r_type
);
1005 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1006 target
->define_tls_base_symbol(symtab
, layout
);
1007 if (optimized_type
== tls::TLSOPT_NONE
)
1009 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1010 Output_data_got
<32, false>* got
1011 = target
->got_section(symtab
, layout
);
1012 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1013 unsigned int shndx
= lsym
.get_st_shndx();
1015 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1017 object
->error(_("local symbol %u has bad shndx %u"),
1020 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1022 target
->rel_dyn_section(layout
),
1023 elfcpp::R_386_TLS_DESC
, 0);
1025 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1026 unsupported_reloc_local(object
, r_type
);
1029 case elfcpp::R_386_TLS_DESC_CALL
:
1032 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1033 if (optimized_type
== tls::TLSOPT_NONE
)
1035 // Create a GOT entry for the module index.
1036 target
->got_mod_index_entry(symtab
, layout
, object
);
1038 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1039 unsupported_reloc_local(object
, r_type
);
1042 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1045 case elfcpp::R_386_TLS_IE
: // Initial-exec
1046 case elfcpp::R_386_TLS_IE_32
:
1047 case elfcpp::R_386_TLS_GOTIE
:
1048 layout
->set_has_static_tls();
1049 if (optimized_type
== tls::TLSOPT_NONE
)
1051 // For the R_386_TLS_IE relocation, we need to create a
1052 // dynamic relocation when building a shared library.
1053 if (r_type
== elfcpp::R_386_TLS_IE
1054 && parameters
->options().shared())
1056 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1058 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1059 rel_dyn
->add_local_relative(object
, r_sym
,
1060 elfcpp::R_386_RELATIVE
,
1061 output_section
, data_shndx
,
1062 reloc
.get_r_offset());
1064 // Create a GOT entry for the tp-relative offset.
1065 Output_data_got
<32, false>* got
1066 = target
->got_section(symtab
, layout
);
1067 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1068 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1069 ? elfcpp::R_386_TLS_TPOFF32
1070 : elfcpp::R_386_TLS_TPOFF
);
1071 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1072 ? GOT_TYPE_TLS_OFFSET
1073 : GOT_TYPE_TLS_NOFFSET
);
1074 got
->add_local_with_rel(object
, r_sym
, got_type
,
1075 target
->rel_dyn_section(layout
),
1078 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1079 unsupported_reloc_local(object
, r_type
);
1082 case elfcpp::R_386_TLS_LE
: // Local-exec
1083 case elfcpp::R_386_TLS_LE_32
:
1084 layout
->set_has_static_tls();
1085 if (output_is_shared
)
1087 // We need to create a dynamic relocation.
1088 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1089 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1090 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1091 ? elfcpp::R_386_TLS_TPOFF32
1092 : elfcpp::R_386_TLS_TPOFF
);
1093 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1094 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1095 data_shndx
, reloc
.get_r_offset());
1105 case elfcpp::R_386_32PLT
:
1106 case elfcpp::R_386_TLS_GD_32
:
1107 case elfcpp::R_386_TLS_GD_PUSH
:
1108 case elfcpp::R_386_TLS_GD_CALL
:
1109 case elfcpp::R_386_TLS_GD_POP
:
1110 case elfcpp::R_386_TLS_LDM_32
:
1111 case elfcpp::R_386_TLS_LDM_PUSH
:
1112 case elfcpp::R_386_TLS_LDM_CALL
:
1113 case elfcpp::R_386_TLS_LDM_POP
:
1114 case elfcpp::R_386_USED_BY_INTEL_200
:
1116 unsupported_reloc_local(object
, r_type
);
1121 // Report an unsupported relocation against a global symbol.
1124 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1125 unsigned int r_type
,
1128 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1129 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1132 // Scan a relocation for a global symbol.
1135 Target_i386::Scan::global(const General_options
&,
1136 Symbol_table
* symtab
,
1138 Target_i386
* target
,
1139 Sized_relobj
<32, false>* object
,
1140 unsigned int data_shndx
,
1141 Output_section
* output_section
,
1142 const elfcpp::Rel
<32, false>& reloc
,
1143 unsigned int r_type
,
1148 case elfcpp::R_386_NONE
:
1149 case elfcpp::R_386_GNU_VTINHERIT
:
1150 case elfcpp::R_386_GNU_VTENTRY
:
1153 case elfcpp::R_386_32
:
1154 case elfcpp::R_386_16
:
1155 case elfcpp::R_386_8
:
1157 // Make a PLT entry if necessary.
1158 if (gsym
->needs_plt_entry())
1160 target
->make_plt_entry(symtab
, layout
, gsym
);
1161 // Since this is not a PC-relative relocation, we may be
1162 // taking the address of a function. In that case we need to
1163 // set the entry in the dynamic symbol table to the address of
1165 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1166 gsym
->set_needs_dynsym_value();
1168 // Make a dynamic relocation if necessary.
1169 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1171 if (target
->may_need_copy_reloc(gsym
))
1173 target
->copy_reloc(symtab
, layout
, object
,
1174 data_shndx
, output_section
, gsym
, reloc
);
1176 else if (r_type
== elfcpp::R_386_32
1177 && gsym
->can_use_relative_reloc(false))
1179 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1180 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1181 output_section
, object
,
1182 data_shndx
, reloc
.get_r_offset());
1186 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1187 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1188 data_shndx
, reloc
.get_r_offset());
1194 case elfcpp::R_386_PC32
:
1195 case elfcpp::R_386_PC16
:
1196 case elfcpp::R_386_PC8
:
1198 // Make a PLT entry if necessary.
1199 if (gsym
->needs_plt_entry())
1201 // These relocations are used for function calls only in
1202 // non-PIC code. For a 32-bit relocation in a shared library,
1203 // we'll need a text relocation anyway, so we can skip the
1204 // PLT entry and let the dynamic linker bind the call directly
1205 // to the target. For smaller relocations, we should use a
1206 // PLT entry to ensure that the call can reach.
1207 if (!parameters
->options().shared()
1208 || r_type
!= elfcpp::R_386_PC32
)
1209 target
->make_plt_entry(symtab
, layout
, gsym
);
1211 // Make a dynamic relocation if necessary.
1212 int flags
= Symbol::NON_PIC_REF
;
1213 if (gsym
->type() == elfcpp::STT_FUNC
)
1214 flags
|= Symbol::FUNCTION_CALL
;
1215 if (gsym
->needs_dynamic_reloc(flags
))
1217 if (target
->may_need_copy_reloc(gsym
))
1219 target
->copy_reloc(symtab
, layout
, object
,
1220 data_shndx
, output_section
, gsym
, reloc
);
1224 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1225 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1226 data_shndx
, reloc
.get_r_offset());
1232 case elfcpp::R_386_GOT32
:
1234 // The symbol requires a GOT entry.
1235 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1236 if (gsym
->final_value_is_known())
1237 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1240 // If this symbol is not fully resolved, we need to add a
1241 // GOT entry with a dynamic relocation.
1242 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1243 if (gsym
->is_from_dynobj()
1244 || gsym
->is_undefined()
1245 || gsym
->is_preemptible())
1246 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1247 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1250 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1251 rel_dyn
->add_global_relative(
1252 gsym
, elfcpp::R_386_RELATIVE
, got
,
1253 gsym
->got_offset(GOT_TYPE_STANDARD
));
1259 case elfcpp::R_386_PLT32
:
1260 // If the symbol is fully resolved, this is just a PC32 reloc.
1261 // Otherwise we need a PLT entry.
1262 if (gsym
->final_value_is_known())
1264 // If building a shared library, we can also skip the PLT entry
1265 // if the symbol is defined in the output file and is protected
1267 if (gsym
->is_defined()
1268 && !gsym
->is_from_dynobj()
1269 && !gsym
->is_preemptible())
1271 target
->make_plt_entry(symtab
, layout
, gsym
);
1274 case elfcpp::R_386_GOTOFF
:
1275 case elfcpp::R_386_GOTPC
:
1276 // We need a GOT section.
1277 target
->got_section(symtab
, layout
);
1280 // These are relocations which should only be seen by the
1281 // dynamic linker, and should never be seen here.
1282 case elfcpp::R_386_COPY
:
1283 case elfcpp::R_386_GLOB_DAT
:
1284 case elfcpp::R_386_JUMP_SLOT
:
1285 case elfcpp::R_386_RELATIVE
:
1286 case elfcpp::R_386_TLS_TPOFF
:
1287 case elfcpp::R_386_TLS_DTPMOD32
:
1288 case elfcpp::R_386_TLS_DTPOFF32
:
1289 case elfcpp::R_386_TLS_TPOFF32
:
1290 case elfcpp::R_386_TLS_DESC
:
1291 gold_error(_("%s: unexpected reloc %u in object file"),
1292 object
->name().c_str(), r_type
);
1295 // These are initial tls relocs, which are expected when
1297 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1298 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1299 case elfcpp::R_386_TLS_DESC_CALL
:
1300 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1301 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1302 case elfcpp::R_386_TLS_IE
: // Initial-exec
1303 case elfcpp::R_386_TLS_IE_32
:
1304 case elfcpp::R_386_TLS_GOTIE
:
1305 case elfcpp::R_386_TLS_LE
: // Local-exec
1306 case elfcpp::R_386_TLS_LE_32
:
1308 const bool is_final
= gsym
->final_value_is_known();
1309 const tls::Tls_optimization optimized_type
1310 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1313 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1314 if (optimized_type
== tls::TLSOPT_NONE
)
1316 // Create a pair of GOT entries for the module index and
1317 // dtv-relative offset.
1318 Output_data_got
<32, false>* got
1319 = target
->got_section(symtab
, layout
);
1320 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1321 target
->rel_dyn_section(layout
),
1322 elfcpp::R_386_TLS_DTPMOD32
,
1323 elfcpp::R_386_TLS_DTPOFF32
);
1325 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1327 // Create a GOT entry for the tp-relative offset.
1328 Output_data_got
<32, false>* got
1329 = target
->got_section(symtab
, layout
);
1330 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1331 target
->rel_dyn_section(layout
),
1332 elfcpp::R_386_TLS_TPOFF
);
1334 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1335 unsupported_reloc_global(object
, r_type
, gsym
);
1338 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1339 target
->define_tls_base_symbol(symtab
, layout
);
1340 if (optimized_type
== tls::TLSOPT_NONE
)
1342 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1343 Output_data_got
<32, false>* got
1344 = target
->got_section(symtab
, layout
);
1345 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
,
1346 target
->rel_dyn_section(layout
),
1347 elfcpp::R_386_TLS_DESC
, 0);
1349 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1351 // Create a GOT entry for the tp-relative offset.
1352 Output_data_got
<32, false>* got
1353 = target
->got_section(symtab
, layout
);
1354 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1355 target
->rel_dyn_section(layout
),
1356 elfcpp::R_386_TLS_TPOFF
);
1358 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1359 unsupported_reloc_global(object
, r_type
, gsym
);
1362 case elfcpp::R_386_TLS_DESC_CALL
:
1365 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1366 if (optimized_type
== tls::TLSOPT_NONE
)
1368 // Create a GOT entry for the module index.
1369 target
->got_mod_index_entry(symtab
, layout
, object
);
1371 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1372 unsupported_reloc_global(object
, r_type
, gsym
);
1375 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1378 case elfcpp::R_386_TLS_IE
: // Initial-exec
1379 case elfcpp::R_386_TLS_IE_32
:
1380 case elfcpp::R_386_TLS_GOTIE
:
1381 layout
->set_has_static_tls();
1382 if (optimized_type
== tls::TLSOPT_NONE
)
1384 // For the R_386_TLS_IE relocation, we need to create a
1385 // dynamic relocation when building a shared library.
1386 if (r_type
== elfcpp::R_386_TLS_IE
1387 && parameters
->options().shared())
1389 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1390 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1391 output_section
, object
,
1393 reloc
.get_r_offset());
1395 // Create a GOT entry for the tp-relative offset.
1396 Output_data_got
<32, false>* got
1397 = target
->got_section(symtab
, layout
);
1398 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1399 ? elfcpp::R_386_TLS_TPOFF32
1400 : elfcpp::R_386_TLS_TPOFF
);
1401 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1402 ? GOT_TYPE_TLS_OFFSET
1403 : GOT_TYPE_TLS_NOFFSET
);
1404 got
->add_global_with_rel(gsym
, got_type
,
1405 target
->rel_dyn_section(layout
),
1408 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1409 unsupported_reloc_global(object
, r_type
, gsym
);
1412 case elfcpp::R_386_TLS_LE
: // Local-exec
1413 case elfcpp::R_386_TLS_LE_32
:
1414 layout
->set_has_static_tls();
1415 if (parameters
->options().shared())
1417 // We need to create a dynamic relocation.
1418 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1419 ? elfcpp::R_386_TLS_TPOFF32
1420 : elfcpp::R_386_TLS_TPOFF
);
1421 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1422 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1423 data_shndx
, reloc
.get_r_offset());
1433 case elfcpp::R_386_32PLT
:
1434 case elfcpp::R_386_TLS_GD_32
:
1435 case elfcpp::R_386_TLS_GD_PUSH
:
1436 case elfcpp::R_386_TLS_GD_CALL
:
1437 case elfcpp::R_386_TLS_GD_POP
:
1438 case elfcpp::R_386_TLS_LDM_32
:
1439 case elfcpp::R_386_TLS_LDM_PUSH
:
1440 case elfcpp::R_386_TLS_LDM_CALL
:
1441 case elfcpp::R_386_TLS_LDM_POP
:
1442 case elfcpp::R_386_USED_BY_INTEL_200
:
1444 unsupported_reloc_global(object
, r_type
, gsym
);
1449 // Scan relocations for a section.
1452 Target_i386::scan_relocs(const General_options
& options
,
1453 Symbol_table
* symtab
,
1455 Sized_relobj
<32, false>* object
,
1456 unsigned int data_shndx
,
1457 unsigned int sh_type
,
1458 const unsigned char* prelocs
,
1460 Output_section
* output_section
,
1461 bool needs_special_offset_handling
,
1462 size_t local_symbol_count
,
1463 const unsigned char* plocal_symbols
)
1465 if (sh_type
== elfcpp::SHT_RELA
)
1467 gold_error(_("%s: unsupported RELA reloc section"),
1468 object
->name().c_str());
1472 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1483 needs_special_offset_handling
,
1488 // Finalize the sections.
1491 Target_i386::do_finalize_sections(Layout
* layout
)
1493 // Fill in some more dynamic tags.
1494 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1497 if (this->got_plt_
!= NULL
)
1498 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1500 if (this->plt_
!= NULL
)
1502 const Output_data
* od
= this->plt_
->rel_plt();
1503 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1504 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1505 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
1508 if (this->rel_dyn_
!= NULL
)
1510 const Output_data
* od
= this->rel_dyn_
;
1511 odyn
->add_section_address(elfcpp::DT_REL
, od
);
1512 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
1513 odyn
->add_constant(elfcpp::DT_RELENT
,
1514 elfcpp::Elf_sizes
<32>::rel_size
);
1517 if (!parameters
->options().shared())
1519 // The value of the DT_DEBUG tag is filled in by the dynamic
1520 // linker at run time, and used by the debugger.
1521 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1525 // Emit any relocs we saved in an attempt to avoid generating COPY
1527 if (this->copy_relocs_
.any_saved_relocs())
1528 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1531 // Return whether a direct absolute static relocation needs to be applied.
1532 // In cases where Scan::local() or Scan::global() has created
1533 // a dynamic relocation other than R_386_RELATIVE, the addend
1534 // of the relocation is carried in the data, and we must not
1535 // apply the static relocation.
1538 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1542 // For local symbols, we will have created a non-RELATIVE dynamic
1543 // relocation only if (a) the output is position independent,
1544 // (b) the relocation is absolute (not pc- or segment-relative), and
1545 // (c) the relocation is not 32 bits wide.
1547 return !(parameters
->options().output_is_position_independent()
1548 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1551 // For global symbols, we use the same helper routines used in the
1552 // scan pass. If we did not create a dynamic relocation, or if we
1553 // created a RELATIVE dynamic relocation, we should apply the static
1555 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1556 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1557 && gsym
->can_use_relative_reloc(ref_flags
1558 & Symbol::FUNCTION_CALL
);
1559 return !has_dyn
|| is_rel
;
1562 // Perform a relocation.
1565 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1566 Target_i386
* target
,
1568 const elfcpp::Rel
<32, false>& rel
,
1569 unsigned int r_type
,
1570 const Sized_symbol
<32>* gsym
,
1571 const Symbol_value
<32>* psymval
,
1572 unsigned char* view
,
1573 elfcpp::Elf_types
<32>::Elf_Addr address
,
1574 section_size_type view_size
)
1576 if (this->skip_call_tls_get_addr_
)
1578 if (r_type
!= elfcpp::R_386_PLT32
1580 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1581 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1582 _("missing expected TLS relocation"));
1585 this->skip_call_tls_get_addr_
= false;
1590 // Pick the value to use for symbols defined in shared objects.
1591 Symbol_value
<32> symval
;
1592 bool is_nonpic
= (r_type
== elfcpp::R_386_PC8
1593 || r_type
== elfcpp::R_386_PC16
1594 || r_type
== elfcpp::R_386_PC32
);
1596 && (gsym
->is_from_dynobj()
1597 || (parameters
->options().shared()
1598 && (gsym
->is_undefined() || gsym
->is_preemptible())))
1599 && gsym
->has_plt_offset()
1600 && (!is_nonpic
|| !parameters
->options().shared()))
1602 symval
.set_output_value(target
->plt_section()->address()
1603 + gsym
->plt_offset());
1607 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1609 // Get the GOT offset if needed.
1610 // The GOT pointer points to the end of the GOT section.
1611 // We need to subtract the size of the GOT section to get
1612 // the actual offset to use in the relocation.
1613 bool have_got_offset
= false;
1614 unsigned int got_offset
= 0;
1617 case elfcpp::R_386_GOT32
:
1620 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1621 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1622 - target
->got_size());
1626 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1627 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1628 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1629 - target
->got_size());
1631 have_got_offset
= true;
1640 case elfcpp::R_386_NONE
:
1641 case elfcpp::R_386_GNU_VTINHERIT
:
1642 case elfcpp::R_386_GNU_VTENTRY
:
1645 case elfcpp::R_386_32
:
1646 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true))
1647 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1650 case elfcpp::R_386_PC32
:
1652 int ref_flags
= Symbol::NON_PIC_REF
;
1653 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1654 ref_flags
|= Symbol::FUNCTION_CALL
;
1655 if (should_apply_static_reloc(gsym
, ref_flags
, true))
1656 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1660 case elfcpp::R_386_16
:
1661 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1662 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1665 case elfcpp::R_386_PC16
:
1667 int ref_flags
= Symbol::NON_PIC_REF
;
1668 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1669 ref_flags
|= Symbol::FUNCTION_CALL
;
1670 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1671 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1675 case elfcpp::R_386_8
:
1676 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1677 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1680 case elfcpp::R_386_PC8
:
1682 int ref_flags
= Symbol::NON_PIC_REF
;
1683 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1684 ref_flags
|= Symbol::FUNCTION_CALL
;
1685 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1686 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1690 case elfcpp::R_386_PLT32
:
1691 gold_assert(gsym
== NULL
1692 || gsym
->has_plt_offset()
1693 || gsym
->final_value_is_known()
1694 || (gsym
->is_defined()
1695 && !gsym
->is_from_dynobj()
1696 && !gsym
->is_preemptible()));
1697 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1700 case elfcpp::R_386_GOT32
:
1701 gold_assert(have_got_offset
);
1702 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1705 case elfcpp::R_386_GOTOFF
:
1707 elfcpp::Elf_types
<32>::Elf_Addr value
;
1708 value
= (psymval
->value(object
, 0)
1709 - target
->got_plt_section()->address());
1710 Relocate_functions
<32, false>::rel32(view
, value
);
1714 case elfcpp::R_386_GOTPC
:
1716 elfcpp::Elf_types
<32>::Elf_Addr value
;
1717 value
= target
->got_plt_section()->address();
1718 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1722 case elfcpp::R_386_COPY
:
1723 case elfcpp::R_386_GLOB_DAT
:
1724 case elfcpp::R_386_JUMP_SLOT
:
1725 case elfcpp::R_386_RELATIVE
:
1726 // These are outstanding tls relocs, which are unexpected when
1728 case elfcpp::R_386_TLS_TPOFF
:
1729 case elfcpp::R_386_TLS_DTPMOD32
:
1730 case elfcpp::R_386_TLS_DTPOFF32
:
1731 case elfcpp::R_386_TLS_TPOFF32
:
1732 case elfcpp::R_386_TLS_DESC
:
1733 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1734 _("unexpected reloc %u in object file"),
1738 // These are initial tls relocs, which are expected when
1740 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1741 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1742 case elfcpp::R_386_TLS_DESC_CALL
:
1743 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1744 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1745 case elfcpp::R_386_TLS_IE
: // Initial-exec
1746 case elfcpp::R_386_TLS_IE_32
:
1747 case elfcpp::R_386_TLS_GOTIE
:
1748 case elfcpp::R_386_TLS_LE
: // Local-exec
1749 case elfcpp::R_386_TLS_LE_32
:
1750 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1751 view
, address
, view_size
);
1754 case elfcpp::R_386_32PLT
:
1755 case elfcpp::R_386_TLS_GD_32
:
1756 case elfcpp::R_386_TLS_GD_PUSH
:
1757 case elfcpp::R_386_TLS_GD_CALL
:
1758 case elfcpp::R_386_TLS_GD_POP
:
1759 case elfcpp::R_386_TLS_LDM_32
:
1760 case elfcpp::R_386_TLS_LDM_PUSH
:
1761 case elfcpp::R_386_TLS_LDM_CALL
:
1762 case elfcpp::R_386_TLS_LDM_POP
:
1763 case elfcpp::R_386_USED_BY_INTEL_200
:
1765 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1766 _("unsupported reloc %u"),
1774 // Perform a TLS relocation.
1777 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1778 Target_i386
* target
,
1780 const elfcpp::Rel
<32, false>& rel
,
1781 unsigned int r_type
,
1782 const Sized_symbol
<32>* gsym
,
1783 const Symbol_value
<32>* psymval
,
1784 unsigned char* view
,
1785 elfcpp::Elf_types
<32>::Elf_Addr
,
1786 section_size_type view_size
)
1788 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1790 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1792 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1794 const bool is_final
=
1796 ? !parameters
->options().output_is_position_independent()
1797 : gsym
->final_value_is_known());
1798 const tls::Tls_optimization optimized_type
1799 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1802 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1803 if (optimized_type
== tls::TLSOPT_TO_LE
)
1805 gold_assert(tls_segment
!= NULL
);
1806 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1807 rel
, r_type
, value
, view
,
1813 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1814 ? GOT_TYPE_TLS_NOFFSET
1815 : GOT_TYPE_TLS_PAIR
);
1816 unsigned int got_offset
;
1819 gold_assert(gsym
->has_got_offset(got_type
));
1820 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1824 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1825 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1826 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1827 - target
->got_size());
1829 if (optimized_type
== tls::TLSOPT_TO_IE
)
1831 gold_assert(tls_segment
!= NULL
);
1832 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1833 got_offset
, view
, view_size
);
1836 else if (optimized_type
== tls::TLSOPT_NONE
)
1838 // Relocate the field with the offset of the pair of GOT
1840 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1844 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1845 _("unsupported reloc %u"),
1849 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1850 case elfcpp::R_386_TLS_DESC_CALL
:
1851 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1852 if (optimized_type
== tls::TLSOPT_TO_LE
)
1854 gold_assert(tls_segment
!= NULL
);
1855 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
1856 rel
, r_type
, value
, view
,
1862 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1863 ? GOT_TYPE_TLS_NOFFSET
1864 : GOT_TYPE_TLS_DESC
);
1865 unsigned int got_offset
;
1868 gold_assert(gsym
->has_got_offset(got_type
));
1869 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1873 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1874 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1875 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1876 - target
->got_size());
1878 if (optimized_type
== tls::TLSOPT_TO_IE
)
1880 gold_assert(tls_segment
!= NULL
);
1881 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1882 got_offset
, view
, view_size
);
1885 else if (optimized_type
== tls::TLSOPT_NONE
)
1887 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
1889 // Relocate the field with the offset of the pair of GOT
1891 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1896 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1897 _("unsupported reloc %u"),
1901 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1902 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
1904 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1905 _("both SUN and GNU model "
1906 "TLS relocations"));
1909 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1910 if (optimized_type
== tls::TLSOPT_TO_LE
)
1912 gold_assert(tls_segment
!= NULL
);
1913 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1914 value
, view
, view_size
);
1917 else if (optimized_type
== tls::TLSOPT_NONE
)
1919 // Relocate the field with the offset of the GOT entry for
1920 // the module index.
1921 unsigned int got_offset
;
1922 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
1923 - target
->got_size());
1924 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1927 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1928 _("unsupported reloc %u"),
1932 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1933 // This reloc can appear in debugging sections, in which case we
1934 // won't see the TLS_LDM reloc. The local_dynamic_type field
1936 if (optimized_type
== tls::TLSOPT_TO_LE
1937 && this->local_dynamic_type_
!= LOCAL_DYNAMIC_NONE
)
1939 gold_assert(tls_segment
!= NULL
);
1940 value
-= tls_segment
->memsz();
1942 Relocate_functions
<32, false>::rel32(view
, value
);
1945 case elfcpp::R_386_TLS_IE
: // Initial-exec
1946 case elfcpp::R_386_TLS_GOTIE
:
1947 case elfcpp::R_386_TLS_IE_32
:
1948 if (optimized_type
== tls::TLSOPT_TO_LE
)
1950 gold_assert(tls_segment
!= NULL
);
1951 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1952 rel
, r_type
, value
, view
,
1956 else if (optimized_type
== tls::TLSOPT_NONE
)
1958 // Relocate the field with the offset of the GOT entry for
1959 // the tp-relative offset of the symbol.
1960 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1961 ? GOT_TYPE_TLS_OFFSET
1962 : GOT_TYPE_TLS_NOFFSET
);
1963 unsigned int got_offset
;
1966 gold_assert(gsym
->has_got_offset(got_type
));
1967 got_offset
= gsym
->got_offset(got_type
);
1971 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1972 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1973 got_offset
= object
->local_got_offset(r_sym
, got_type
);
1975 // For the R_386_TLS_IE relocation, we need to apply the
1976 // absolute address of the GOT entry.
1977 if (r_type
== elfcpp::R_386_TLS_IE
)
1978 got_offset
+= target
->got_plt_section()->address();
1979 // All GOT offsets are relative to the end of the GOT.
1980 got_offset
-= target
->got_size();
1981 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1984 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1985 _("unsupported reloc %u"),
1989 case elfcpp::R_386_TLS_LE
: // Local-exec
1990 // If we're creating a shared library, a dynamic relocation will
1991 // have been created for this location, so do not apply it now.
1992 if (!parameters
->options().shared())
1994 gold_assert(tls_segment
!= NULL
);
1995 value
-= tls_segment
->memsz();
1996 Relocate_functions
<32, false>::rel32(view
, value
);
2000 case elfcpp::R_386_TLS_LE_32
:
2001 // If we're creating a shared library, a dynamic relocation will
2002 // have been created for this location, so do not apply it now.
2003 if (!parameters
->options().shared())
2005 gold_assert(tls_segment
!= NULL
);
2006 value
= tls_segment
->memsz() - value
;
2007 Relocate_functions
<32, false>::rel32(view
, value
);
2013 // Do a relocation in which we convert a TLS General-Dynamic to a
2017 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2019 Output_segment
* tls_segment
,
2020 const elfcpp::Rel
<32, false>& rel
,
2022 elfcpp::Elf_types
<32>::Elf_Addr value
,
2023 unsigned char* view
,
2024 section_size_type view_size
)
2026 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2027 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2028 // leal foo(%reg),%eax; call ___tls_get_addr
2029 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2031 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2032 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2034 unsigned char op1
= view
[-1];
2035 unsigned char op2
= view
[-2];
2037 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2038 op2
== 0x8d || op2
== 0x04);
2039 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2045 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2046 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2047 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2048 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2049 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2053 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2054 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2055 if (rel
.get_r_offset() + 9 < view_size
2058 // There is a trailing nop. Use the size byte subl.
2059 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2064 // Use the five byte subl.
2065 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2069 value
= tls_segment
->memsz() - value
;
2070 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2072 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2074 this->skip_call_tls_get_addr_
= true;
2077 // Do a relocation in which we convert a TLS General-Dynamic to an
2081 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2084 const elfcpp::Rel
<32, false>& rel
,
2086 elfcpp::Elf_types
<32>::Elf_Addr value
,
2087 unsigned char* view
,
2088 section_size_type view_size
)
2090 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2091 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2093 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2094 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2096 unsigned char op1
= view
[-1];
2097 unsigned char op2
= view
[-2];
2099 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2100 op2
== 0x8d || op2
== 0x04);
2101 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2105 // FIXME: For now, support only the first (SIB) form.
2106 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2110 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2111 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2112 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2113 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2114 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2118 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2119 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2120 if (rel
.get_r_offset() + 9 < view_size
2123 // FIXME: This is not the right instruction sequence.
2124 // There is a trailing nop. Use the size byte subl.
2125 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2130 // FIXME: This is not the right instruction sequence.
2131 // Use the five byte subl.
2132 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2136 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2138 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2140 this->skip_call_tls_get_addr_
= true;
2143 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2144 // General-Dynamic to a Local-Exec.
2147 Target_i386::Relocate::tls_desc_gd_to_le(
2148 const Relocate_info
<32, false>* relinfo
,
2150 Output_segment
* tls_segment
,
2151 const elfcpp::Rel
<32, false>& rel
,
2152 unsigned int r_type
,
2153 elfcpp::Elf_types
<32>::Elf_Addr value
,
2154 unsigned char* view
,
2155 section_size_type view_size
)
2157 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2159 // leal foo@TLSDESC(%ebx), %eax
2160 // ==> leal foo@NTPOFF, %eax
2161 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2162 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2163 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2164 view
[-2] == 0x8d && view
[-1] == 0x83);
2166 value
-= tls_segment
->memsz();
2167 Relocate_functions
<32, false>::rel32(view
, value
);
2171 // call *foo@TLSCALL(%eax)
2173 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2174 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2175 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2176 view
[0] == 0xff && view
[1] == 0x10);
2182 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2183 // General-Dynamic to an Initial-Exec.
2186 Target_i386::Relocate::tls_desc_gd_to_ie(
2187 const Relocate_info
<32, false>* relinfo
,
2190 const elfcpp::Rel
<32, false>& rel
,
2191 unsigned int r_type
,
2192 elfcpp::Elf_types
<32>::Elf_Addr value
,
2193 unsigned char* view
,
2194 section_size_type view_size
)
2196 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2198 // leal foo@TLSDESC(%ebx), %eax
2199 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2200 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2201 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2202 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2203 view
[-2] == 0x8d && view
[-1] == 0x83);
2205 Relocate_functions
<32, false>::rel32(view
, value
);
2209 // call *foo@TLSCALL(%eax)
2211 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2212 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2213 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2214 view
[0] == 0xff && view
[1] == 0x10);
2220 // Do a relocation in which we convert a TLS Local-Dynamic to a
2224 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2227 const elfcpp::Rel
<32, false>& rel
,
2229 elfcpp::Elf_types
<32>::Elf_Addr
,
2230 unsigned char* view
,
2231 section_size_type view_size
)
2233 // leal foo(%reg), %eax; call ___tls_get_addr
2234 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2236 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2237 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2239 // FIXME: Does this test really always pass?
2240 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2241 view
[-2] == 0x8d && view
[-1] == 0x83);
2243 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2245 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2247 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2249 this->skip_call_tls_get_addr_
= true;
2252 // Do a relocation in which we convert a TLS Initial-Exec to a
2256 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2258 Output_segment
* tls_segment
,
2259 const elfcpp::Rel
<32, false>& rel
,
2260 unsigned int r_type
,
2261 elfcpp::Elf_types
<32>::Elf_Addr value
,
2262 unsigned char* view
,
2263 section_size_type view_size
)
2265 // We have to actually change the instructions, which means that we
2266 // need to examine the opcodes to figure out which instruction we
2268 if (r_type
== elfcpp::R_386_TLS_IE
)
2270 // movl %gs:XX,%eax ==> movl $YY,%eax
2271 // movl %gs:XX,%reg ==> movl $YY,%reg
2272 // addl %gs:XX,%reg ==> addl $YY,%reg
2273 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2274 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2276 unsigned char op1
= view
[-1];
2279 // movl XX,%eax ==> movl $YY,%eax
2284 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2286 unsigned char op2
= view
[-2];
2289 // movl XX,%reg ==> movl $YY,%reg
2290 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2291 (op1
& 0xc7) == 0x05);
2293 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2295 else if (op2
== 0x03)
2297 // addl XX,%reg ==> addl $YY,%reg
2298 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2299 (op1
& 0xc7) == 0x05);
2301 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2304 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2309 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2310 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2311 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2312 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2313 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2315 unsigned char op1
= view
[-1];
2316 unsigned char op2
= view
[-2];
2317 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2318 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2321 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2323 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2325 else if (op2
== 0x2b)
2327 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2329 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2331 else if (op2
== 0x03)
2333 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2335 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2338 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2341 value
= tls_segment
->memsz() - value
;
2342 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2345 Relocate_functions
<32, false>::rel32(view
, value
);
2348 // Relocate section data.
2351 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2352 unsigned int sh_type
,
2353 const unsigned char* prelocs
,
2355 Output_section
* output_section
,
2356 bool needs_special_offset_handling
,
2357 unsigned char* view
,
2358 elfcpp::Elf_types
<32>::Elf_Addr address
,
2359 section_size_type view_size
)
2361 gold_assert(sh_type
== elfcpp::SHT_REL
);
2363 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2364 Target_i386::Relocate
>(
2370 needs_special_offset_handling
,
2376 // Return the size of a relocation while scanning during a relocatable
2380 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2381 unsigned int r_type
,
2386 case elfcpp::R_386_NONE
:
2387 case elfcpp::R_386_GNU_VTINHERIT
:
2388 case elfcpp::R_386_GNU_VTENTRY
:
2389 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2390 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2391 case elfcpp::R_386_TLS_DESC_CALL
:
2392 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2393 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2394 case elfcpp::R_386_TLS_IE
: // Initial-exec
2395 case elfcpp::R_386_TLS_IE_32
:
2396 case elfcpp::R_386_TLS_GOTIE
:
2397 case elfcpp::R_386_TLS_LE
: // Local-exec
2398 case elfcpp::R_386_TLS_LE_32
:
2401 case elfcpp::R_386_32
:
2402 case elfcpp::R_386_PC32
:
2403 case elfcpp::R_386_GOT32
:
2404 case elfcpp::R_386_PLT32
:
2405 case elfcpp::R_386_GOTOFF
:
2406 case elfcpp::R_386_GOTPC
:
2409 case elfcpp::R_386_16
:
2410 case elfcpp::R_386_PC16
:
2413 case elfcpp::R_386_8
:
2414 case elfcpp::R_386_PC8
:
2417 // These are relocations which should only be seen by the
2418 // dynamic linker, and should never be seen here.
2419 case elfcpp::R_386_COPY
:
2420 case elfcpp::R_386_GLOB_DAT
:
2421 case elfcpp::R_386_JUMP_SLOT
:
2422 case elfcpp::R_386_RELATIVE
:
2423 case elfcpp::R_386_TLS_TPOFF
:
2424 case elfcpp::R_386_TLS_DTPMOD32
:
2425 case elfcpp::R_386_TLS_DTPOFF32
:
2426 case elfcpp::R_386_TLS_TPOFF32
:
2427 case elfcpp::R_386_TLS_DESC
:
2428 object
->error(_("unexpected reloc %u in object file"), r_type
);
2431 case elfcpp::R_386_32PLT
:
2432 case elfcpp::R_386_TLS_GD_32
:
2433 case elfcpp::R_386_TLS_GD_PUSH
:
2434 case elfcpp::R_386_TLS_GD_CALL
:
2435 case elfcpp::R_386_TLS_GD_POP
:
2436 case elfcpp::R_386_TLS_LDM_32
:
2437 case elfcpp::R_386_TLS_LDM_PUSH
:
2438 case elfcpp::R_386_TLS_LDM_CALL
:
2439 case elfcpp::R_386_TLS_LDM_POP
:
2440 case elfcpp::R_386_USED_BY_INTEL_200
:
2442 object
->error(_("unsupported reloc %u in object file"), r_type
);
2447 // Scan the relocs during a relocatable link.
2450 Target_i386::scan_relocatable_relocs(const General_options
& options
,
2451 Symbol_table
* symtab
,
2453 Sized_relobj
<32, false>* object
,
2454 unsigned int data_shndx
,
2455 unsigned int sh_type
,
2456 const unsigned char* prelocs
,
2458 Output_section
* output_section
,
2459 bool needs_special_offset_handling
,
2460 size_t local_symbol_count
,
2461 const unsigned char* plocal_symbols
,
2462 Relocatable_relocs
* rr
)
2464 gold_assert(sh_type
== elfcpp::SHT_REL
);
2466 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2467 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2469 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2470 Scan_relocatable_relocs
>(
2479 needs_special_offset_handling
,
2485 // Relocate a section during a relocatable link.
2488 Target_i386::relocate_for_relocatable(
2489 const Relocate_info
<32, false>* relinfo
,
2490 unsigned int sh_type
,
2491 const unsigned char* prelocs
,
2493 Output_section
* output_section
,
2494 off_t offset_in_output_section
,
2495 const Relocatable_relocs
* rr
,
2496 unsigned char* view
,
2497 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2498 section_size_type view_size
,
2499 unsigned char* reloc_view
,
2500 section_size_type reloc_view_size
)
2502 gold_assert(sh_type
== elfcpp::SHT_REL
);
2504 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2509 offset_in_output_section
,
2518 // Return the value to use for a dynamic which requires special
2519 // treatment. This is how we support equality comparisons of function
2520 // pointers across shared library boundaries, as described in the
2521 // processor specific ABI supplement.
2524 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2526 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2527 return this->plt_section()->address() + gsym
->plt_offset();
2530 // Return a string used to fill a code section with nops to take up
2531 // the specified length.
2534 Target_i386::do_code_fill(section_size_type length
) const
2538 // Build a jmp instruction to skip over the bytes.
2539 unsigned char jmp
[5];
2541 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2542 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2543 + std::string(length
- 5, '\0'));
2546 // Nop sequences of various lengths.
2547 const char nop1
[1] = { 0x90 }; // nop
2548 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2549 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2550 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2551 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2552 0x00 }; // leal 0(%esi,1),%esi
2553 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2555 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2557 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2558 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2559 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2560 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2562 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2563 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2565 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2566 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2568 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2569 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2570 0x00, 0x00, 0x00, 0x00 };
2571 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2572 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2573 0x27, 0x00, 0x00, 0x00,
2575 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2576 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2577 0xbc, 0x27, 0x00, 0x00,
2579 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2580 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2581 0x90, 0x90, 0x90, 0x90,
2584 const char* nops
[16] = {
2586 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2587 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2590 return std::string(nops
[length
], length
);
2593 // The selector for i386 object files.
2595 class Target_selector_i386
: public Target_selector
2598 Target_selector_i386()
2599 : Target_selector(elfcpp::EM_386
, 32, false, "elf32-i386")
2603 do_instantiate_target()
2604 { return new Target_i386(); }
2607 Target_selector_i386 target_selector_i386
;
2609 } // End anonymous namespace.