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>();
429 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
430 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
433 // The old GNU linker creates a .got.plt section. We just
434 // create another set of data in the .got section. Note that we
435 // always create a PLT if we create a GOT, although the PLT
437 this->got_plt_
= new Output_data_space(4);
438 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
439 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
442 // The first three entries are reserved.
443 this->got_plt_
->set_current_data_size(3 * 4);
445 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
446 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
448 0, 0, elfcpp::STT_OBJECT
,
450 elfcpp::STV_HIDDEN
, 0,
457 // Get the dynamic reloc section, creating it if necessary.
459 Target_i386::Reloc_section
*
460 Target_i386::rel_dyn_section(Layout
* layout
)
462 if (this->rel_dyn_
== NULL
)
464 gold_assert(layout
!= NULL
);
465 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
466 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
467 elfcpp::SHF_ALLOC
, this->rel_dyn_
);
469 return this->rel_dyn_
;
472 // A class to handle the PLT data.
474 class Output_data_plt_i386
: public Output_section_data
477 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
479 Output_data_plt_i386(Layout
*, Output_data_space
*);
481 // Add an entry to the PLT.
483 add_entry(Symbol
* gsym
);
485 // Return the .rel.plt section data.
488 { return this->rel_
; }
492 do_adjust_output_section(Output_section
* os
);
495 // The size of an entry in the PLT.
496 static const int plt_entry_size
= 16;
498 // The first entry in the PLT for an executable.
499 static unsigned char exec_first_plt_entry
[plt_entry_size
];
501 // The first entry in the PLT for a shared object.
502 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
504 // Other entries in the PLT for an executable.
505 static unsigned char exec_plt_entry
[plt_entry_size
];
507 // Other entries in the PLT for a shared object.
508 static unsigned char dyn_plt_entry
[plt_entry_size
];
510 // Set the final size.
512 set_final_data_size()
513 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
515 // Write out the PLT data.
517 do_write(Output_file
*);
519 // The reloc section.
521 // The .got.plt section.
522 Output_data_space
* got_plt_
;
523 // The number of PLT entries.
527 // Create the PLT section. The ordinary .got section is an argument,
528 // since we need to refer to the start. We also create our own .got
529 // section just for PLT entries.
531 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
532 Output_data_space
* got_plt
)
533 : Output_section_data(4), got_plt_(got_plt
), count_(0)
535 this->rel_
= new Reloc_section(false);
536 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
537 elfcpp::SHF_ALLOC
, this->rel_
);
541 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
543 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
544 // linker, and so do we.
548 // Add an entry to the PLT.
551 Output_data_plt_i386::add_entry(Symbol
* gsym
)
553 gold_assert(!gsym
->has_plt_offset());
555 // Note that when setting the PLT offset we skip the initial
556 // reserved PLT entry.
557 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
561 section_offset_type got_offset
= this->got_plt_
->current_data_size();
563 // Every PLT entry needs a GOT entry which points back to the PLT
564 // entry (this will be changed by the dynamic linker, normally
565 // lazily when the function is called).
566 this->got_plt_
->set_current_data_size(got_offset
+ 4);
568 // Every PLT entry needs a reloc.
569 gsym
->set_needs_dynsym_entry();
570 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
573 // Note that we don't need to save the symbol. The contents of the
574 // PLT are independent of which symbols are used. The symbols only
575 // appear in the relocations.
578 // The first entry in the PLT for an executable.
580 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
582 0xff, 0x35, // pushl contents of memory address
583 0, 0, 0, 0, // replaced with address of .got + 4
584 0xff, 0x25, // jmp indirect
585 0, 0, 0, 0, // replaced with address of .got + 8
589 // The first entry in the PLT for a shared object.
591 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
593 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
594 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
598 // Subsequent entries in the PLT for an executable.
600 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
602 0xff, 0x25, // jmp indirect
603 0, 0, 0, 0, // replaced with address of symbol in .got
604 0x68, // pushl immediate
605 0, 0, 0, 0, // replaced with offset into relocation table
606 0xe9, // jmp relative
607 0, 0, 0, 0 // replaced with offset to start of .plt
610 // Subsequent entries in the PLT for a shared object.
612 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
614 0xff, 0xa3, // jmp *offset(%ebx)
615 0, 0, 0, 0, // replaced with offset of symbol in .got
616 0x68, // pushl immediate
617 0, 0, 0, 0, // replaced with offset into relocation table
618 0xe9, // jmp relative
619 0, 0, 0, 0 // replaced with offset to start of .plt
622 // Write out the PLT. This uses the hand-coded instructions above,
623 // and adjusts them as needed. This is all specified by the i386 ELF
624 // Processor Supplement.
627 Output_data_plt_i386::do_write(Output_file
* of
)
629 const off_t offset
= this->offset();
630 const section_size_type oview_size
=
631 convert_to_section_size_type(this->data_size());
632 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
634 const off_t got_file_offset
= this->got_plt_
->offset();
635 const section_size_type got_size
=
636 convert_to_section_size_type(this->got_plt_
->data_size());
637 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
640 unsigned char* pov
= oview
;
642 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
643 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
645 if (parameters
->options().shared())
646 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
649 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
650 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
651 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
653 pov
+= plt_entry_size
;
655 unsigned char* got_pov
= got_view
;
657 memset(got_pov
, 0, 12);
660 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
662 unsigned int plt_offset
= plt_entry_size
;
663 unsigned int plt_rel_offset
= 0;
664 unsigned int got_offset
= 12;
665 const unsigned int count
= this->count_
;
666 for (unsigned int i
= 0;
669 pov
+= plt_entry_size
,
671 plt_offset
+= plt_entry_size
,
672 plt_rel_offset
+= rel_size
,
675 // Set and adjust the PLT entry itself.
677 if (parameters
->options().shared())
679 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
680 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
684 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
685 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
690 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
691 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
692 - (plt_offset
+ plt_entry_size
));
694 // Set the entry in the GOT.
695 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
698 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
699 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
701 of
->write_output_view(offset
, oview_size
, oview
);
702 of
->write_output_view(got_file_offset
, got_size
, got_view
);
705 // Create a PLT entry for a global symbol.
708 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
710 if (gsym
->has_plt_offset())
713 if (this->plt_
== NULL
)
715 // Create the GOT sections first.
716 this->got_section(symtab
, layout
);
718 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
719 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
721 | elfcpp::SHF_EXECINSTR
),
725 this->plt_
->add_entry(gsym
);
728 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
731 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
733 if (this->tls_base_symbol_defined_
)
736 Output_segment
* tls_segment
= layout
->tls_segment();
737 if (tls_segment
!= NULL
)
739 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
743 elfcpp::STV_HIDDEN
, 0,
744 Symbol::SEGMENT_END
, true);
746 this->tls_base_symbol_defined_
= true;
749 // Create a GOT entry for the TLS module index.
752 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
753 Sized_relobj
<32, false>* object
)
755 if (this->got_mod_index_offset_
== -1U)
757 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
758 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
759 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
760 unsigned int got_offset
= got
->add_constant(0);
761 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
763 got
->add_constant(0);
764 this->got_mod_index_offset_
= got_offset
;
766 return this->got_mod_index_offset_
;
769 // Optimize the TLS relocation type based on what we know about the
770 // symbol. IS_FINAL is true if the final address of this symbol is
771 // known at link time.
773 tls::Tls_optimization
774 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
776 // If we are generating a shared library, then we can't do anything
778 if (parameters
->options().shared())
779 return tls::TLSOPT_NONE
;
783 case elfcpp::R_386_TLS_GD
:
784 case elfcpp::R_386_TLS_GOTDESC
:
785 case elfcpp::R_386_TLS_DESC_CALL
:
786 // These are General-Dynamic which permits fully general TLS
787 // access. Since we know that we are generating an executable,
788 // we can convert this to Initial-Exec. If we also know that
789 // this is a local symbol, we can further switch to Local-Exec.
791 return tls::TLSOPT_TO_LE
;
792 return tls::TLSOPT_TO_IE
;
794 case elfcpp::R_386_TLS_LDM
:
795 // This is Local-Dynamic, which refers to a local symbol in the
796 // dynamic TLS block. Since we know that we generating an
797 // executable, we can switch to Local-Exec.
798 return tls::TLSOPT_TO_LE
;
800 case elfcpp::R_386_TLS_LDO_32
:
801 // Another type of Local-Dynamic relocation.
802 return tls::TLSOPT_TO_LE
;
804 case elfcpp::R_386_TLS_IE
:
805 case elfcpp::R_386_TLS_GOTIE
:
806 case elfcpp::R_386_TLS_IE_32
:
807 // These are Initial-Exec relocs which get the thread offset
808 // from the GOT. If we know that we are linking against the
809 // local symbol, we can switch to Local-Exec, which links the
810 // thread offset into the instruction.
812 return tls::TLSOPT_TO_LE
;
813 return tls::TLSOPT_NONE
;
815 case elfcpp::R_386_TLS_LE
:
816 case elfcpp::R_386_TLS_LE_32
:
817 // When we already have Local-Exec, there is nothing further we
819 return tls::TLSOPT_NONE
;
826 // Report an unsupported relocation against a local symbol.
829 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
832 gold_error(_("%s: unsupported reloc %u against local symbol"),
833 object
->name().c_str(), r_type
);
836 // Scan a relocation for a local symbol.
839 Target_i386::Scan::local(const General_options
&,
840 Symbol_table
* symtab
,
843 Sized_relobj
<32, false>* object
,
844 unsigned int data_shndx
,
845 Output_section
* output_section
,
846 const elfcpp::Rel
<32, false>& reloc
,
848 const elfcpp::Sym
<32, false>& lsym
)
852 case elfcpp::R_386_NONE
:
853 case elfcpp::R_386_GNU_VTINHERIT
:
854 case elfcpp::R_386_GNU_VTENTRY
:
857 case elfcpp::R_386_32
:
858 // If building a shared library (or a position-independent
859 // executable), we need to create a dynamic relocation for
860 // this location. The relocation applied at link time will
861 // apply the link-time value, so we flag the location with
862 // an R_386_RELATIVE relocation so the dynamic loader can
863 // relocate it easily.
864 if (parameters
->options().output_is_position_independent())
866 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
867 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
868 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
869 output_section
, data_shndx
,
870 reloc
.get_r_offset());
874 case elfcpp::R_386_16
:
875 case elfcpp::R_386_8
:
876 // If building a shared library (or a position-independent
877 // executable), we need to create a dynamic relocation for
878 // this location. Because the addend needs to remain in the
879 // data section, we need to be careful not to apply this
880 // relocation statically.
881 if (parameters
->options().output_is_position_independent())
883 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
884 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
885 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
886 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
887 data_shndx
, reloc
.get_r_offset());
890 gold_assert(lsym
.get_st_value() == 0);
891 unsigned int shndx
= lsym
.get_st_shndx();
893 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
896 object
->error(_("section symbol %u has bad shndx %u"),
899 rel_dyn
->add_local_section(object
, shndx
,
900 r_type
, output_section
,
901 data_shndx
, reloc
.get_r_offset());
906 case elfcpp::R_386_PC32
:
907 case elfcpp::R_386_PC16
:
908 case elfcpp::R_386_PC8
:
911 case elfcpp::R_386_PLT32
:
912 // Since we know this is a local symbol, we can handle this as a
916 case elfcpp::R_386_GOTOFF
:
917 case elfcpp::R_386_GOTPC
:
918 // We need a GOT section.
919 target
->got_section(symtab
, layout
);
922 case elfcpp::R_386_GOT32
:
924 // The symbol requires a GOT entry.
925 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
926 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
927 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
929 // If we are generating a shared object, we need to add a
930 // dynamic RELATIVE relocation for this symbol's GOT entry.
931 if (parameters
->options().output_is_position_independent())
933 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
934 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
935 rel_dyn
->add_local_relative(
936 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
937 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
943 // These are relocations which should only be seen by the
944 // dynamic linker, and should never be seen here.
945 case elfcpp::R_386_COPY
:
946 case elfcpp::R_386_GLOB_DAT
:
947 case elfcpp::R_386_JUMP_SLOT
:
948 case elfcpp::R_386_RELATIVE
:
949 case elfcpp::R_386_TLS_TPOFF
:
950 case elfcpp::R_386_TLS_DTPMOD32
:
951 case elfcpp::R_386_TLS_DTPOFF32
:
952 case elfcpp::R_386_TLS_TPOFF32
:
953 case elfcpp::R_386_TLS_DESC
:
954 gold_error(_("%s: unexpected reloc %u in object file"),
955 object
->name().c_str(), r_type
);
958 // These are initial TLS relocs, which are expected when
960 case elfcpp::R_386_TLS_GD
: // Global-dynamic
961 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
962 case elfcpp::R_386_TLS_DESC_CALL
:
963 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
964 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
965 case elfcpp::R_386_TLS_IE
: // Initial-exec
966 case elfcpp::R_386_TLS_IE_32
:
967 case elfcpp::R_386_TLS_GOTIE
:
968 case elfcpp::R_386_TLS_LE
: // Local-exec
969 case elfcpp::R_386_TLS_LE_32
:
971 bool output_is_shared
= parameters
->options().shared();
972 const tls::Tls_optimization optimized_type
973 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
976 case elfcpp::R_386_TLS_GD
: // Global-dynamic
977 if (optimized_type
== tls::TLSOPT_NONE
)
979 // Create a pair of GOT entries for the module index and
980 // dtv-relative offset.
981 Output_data_got
<32, false>* got
982 = target
->got_section(symtab
, layout
);
983 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
984 unsigned int shndx
= lsym
.get_st_shndx();
986 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
988 object
->error(_("local symbol %u has bad shndx %u"),
991 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
993 target
->rel_dyn_section(layout
),
994 elfcpp::R_386_TLS_DTPMOD32
, 0);
996 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
997 unsupported_reloc_local(object
, r_type
);
1000 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1001 target
->define_tls_base_symbol(symtab
, layout
);
1002 if (optimized_type
== tls::TLSOPT_NONE
)
1004 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1005 Output_data_got
<32, false>* got
1006 = target
->got_section(symtab
, layout
);
1007 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1008 unsigned int shndx
= lsym
.get_st_shndx();
1010 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1012 object
->error(_("local symbol %u has bad shndx %u"),
1015 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1017 target
->rel_dyn_section(layout
),
1018 elfcpp::R_386_TLS_DESC
, 0);
1020 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1021 unsupported_reloc_local(object
, r_type
);
1024 case elfcpp::R_386_TLS_DESC_CALL
:
1027 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1028 if (optimized_type
== tls::TLSOPT_NONE
)
1030 // Create a GOT entry for the module index.
1031 target
->got_mod_index_entry(symtab
, layout
, object
);
1033 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1034 unsupported_reloc_local(object
, r_type
);
1037 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1040 case elfcpp::R_386_TLS_IE
: // Initial-exec
1041 case elfcpp::R_386_TLS_IE_32
:
1042 case elfcpp::R_386_TLS_GOTIE
:
1043 layout
->set_has_static_tls();
1044 if (optimized_type
== tls::TLSOPT_NONE
)
1046 // For the R_386_TLS_IE relocation, we need to create a
1047 // dynamic relocation when building a shared library.
1048 if (r_type
== elfcpp::R_386_TLS_IE
1049 && parameters
->options().shared())
1051 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1053 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1054 rel_dyn
->add_local_relative(object
, r_sym
,
1055 elfcpp::R_386_RELATIVE
,
1056 output_section
, data_shndx
,
1057 reloc
.get_r_offset());
1059 // Create a GOT entry for the tp-relative offset.
1060 Output_data_got
<32, false>* got
1061 = target
->got_section(symtab
, layout
);
1062 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1063 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1064 ? elfcpp::R_386_TLS_TPOFF32
1065 : elfcpp::R_386_TLS_TPOFF
);
1066 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1067 ? GOT_TYPE_TLS_OFFSET
1068 : GOT_TYPE_TLS_NOFFSET
);
1069 got
->add_local_with_rel(object
, r_sym
, got_type
,
1070 target
->rel_dyn_section(layout
),
1073 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1074 unsupported_reloc_local(object
, r_type
);
1077 case elfcpp::R_386_TLS_LE
: // Local-exec
1078 case elfcpp::R_386_TLS_LE_32
:
1079 layout
->set_has_static_tls();
1080 if (output_is_shared
)
1082 // We need to create a dynamic relocation.
1083 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1084 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1085 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1086 ? elfcpp::R_386_TLS_TPOFF32
1087 : elfcpp::R_386_TLS_TPOFF
);
1088 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1089 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1090 data_shndx
, reloc
.get_r_offset());
1100 case elfcpp::R_386_32PLT
:
1101 case elfcpp::R_386_TLS_GD_32
:
1102 case elfcpp::R_386_TLS_GD_PUSH
:
1103 case elfcpp::R_386_TLS_GD_CALL
:
1104 case elfcpp::R_386_TLS_GD_POP
:
1105 case elfcpp::R_386_TLS_LDM_32
:
1106 case elfcpp::R_386_TLS_LDM_PUSH
:
1107 case elfcpp::R_386_TLS_LDM_CALL
:
1108 case elfcpp::R_386_TLS_LDM_POP
:
1109 case elfcpp::R_386_USED_BY_INTEL_200
:
1111 unsupported_reloc_local(object
, r_type
);
1116 // Report an unsupported relocation against a global symbol.
1119 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1120 unsigned int r_type
,
1123 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1124 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1127 // Scan a relocation for a global symbol.
1130 Target_i386::Scan::global(const General_options
&,
1131 Symbol_table
* symtab
,
1133 Target_i386
* target
,
1134 Sized_relobj
<32, false>* object
,
1135 unsigned int data_shndx
,
1136 Output_section
* output_section
,
1137 const elfcpp::Rel
<32, false>& reloc
,
1138 unsigned int r_type
,
1143 case elfcpp::R_386_NONE
:
1144 case elfcpp::R_386_GNU_VTINHERIT
:
1145 case elfcpp::R_386_GNU_VTENTRY
:
1148 case elfcpp::R_386_32
:
1149 case elfcpp::R_386_16
:
1150 case elfcpp::R_386_8
:
1152 // Make a PLT entry if necessary.
1153 if (gsym
->needs_plt_entry())
1155 target
->make_plt_entry(symtab
, layout
, gsym
);
1156 // Since this is not a PC-relative relocation, we may be
1157 // taking the address of a function. In that case we need to
1158 // set the entry in the dynamic symbol table to the address of
1160 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1161 gsym
->set_needs_dynsym_value();
1163 // Make a dynamic relocation if necessary.
1164 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1166 if (target
->may_need_copy_reloc(gsym
))
1168 target
->copy_reloc(symtab
, layout
, object
,
1169 data_shndx
, output_section
, gsym
, reloc
);
1171 else if (r_type
== elfcpp::R_386_32
1172 && gsym
->can_use_relative_reloc(false))
1174 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1175 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1176 output_section
, object
,
1177 data_shndx
, reloc
.get_r_offset());
1181 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1182 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1183 data_shndx
, reloc
.get_r_offset());
1189 case elfcpp::R_386_PC32
:
1190 case elfcpp::R_386_PC16
:
1191 case elfcpp::R_386_PC8
:
1193 // Make a PLT entry if necessary.
1194 if (gsym
->needs_plt_entry())
1196 // These relocations are used for function calls only in
1197 // non-PIC code. For a 32-bit relocation in a shared library,
1198 // we'll need a text relocation anyway, so we can skip the
1199 // PLT entry and let the dynamic linker bind the call directly
1200 // to the target. For smaller relocations, we should use a
1201 // PLT entry to ensure that the call can reach.
1202 if (!parameters
->options().shared()
1203 || r_type
!= elfcpp::R_386_PC32
)
1204 target
->make_plt_entry(symtab
, layout
, gsym
);
1206 // Make a dynamic relocation if necessary.
1207 int flags
= Symbol::NON_PIC_REF
;
1208 if (gsym
->type() == elfcpp::STT_FUNC
)
1209 flags
|= Symbol::FUNCTION_CALL
;
1210 if (gsym
->needs_dynamic_reloc(flags
))
1212 if (target
->may_need_copy_reloc(gsym
))
1214 target
->copy_reloc(symtab
, layout
, object
,
1215 data_shndx
, output_section
, gsym
, reloc
);
1219 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1220 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1221 data_shndx
, reloc
.get_r_offset());
1227 case elfcpp::R_386_GOT32
:
1229 // The symbol requires a GOT entry.
1230 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1231 if (gsym
->final_value_is_known())
1232 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1235 // If this symbol is not fully resolved, we need to add a
1236 // GOT entry with a dynamic relocation.
1237 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1238 if (gsym
->is_from_dynobj()
1239 || gsym
->is_undefined()
1240 || gsym
->is_preemptible())
1241 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1242 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1245 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1246 rel_dyn
->add_global_relative(
1247 gsym
, elfcpp::R_386_RELATIVE
, got
,
1248 gsym
->got_offset(GOT_TYPE_STANDARD
));
1254 case elfcpp::R_386_PLT32
:
1255 // If the symbol is fully resolved, this is just a PC32 reloc.
1256 // Otherwise we need a PLT entry.
1257 if (gsym
->final_value_is_known())
1259 // If building a shared library, we can also skip the PLT entry
1260 // if the symbol is defined in the output file and is protected
1262 if (gsym
->is_defined()
1263 && !gsym
->is_from_dynobj()
1264 && !gsym
->is_preemptible())
1266 target
->make_plt_entry(symtab
, layout
, gsym
);
1269 case elfcpp::R_386_GOTOFF
:
1270 case elfcpp::R_386_GOTPC
:
1271 // We need a GOT section.
1272 target
->got_section(symtab
, layout
);
1275 // These are relocations which should only be seen by the
1276 // dynamic linker, and should never be seen here.
1277 case elfcpp::R_386_COPY
:
1278 case elfcpp::R_386_GLOB_DAT
:
1279 case elfcpp::R_386_JUMP_SLOT
:
1280 case elfcpp::R_386_RELATIVE
:
1281 case elfcpp::R_386_TLS_TPOFF
:
1282 case elfcpp::R_386_TLS_DTPMOD32
:
1283 case elfcpp::R_386_TLS_DTPOFF32
:
1284 case elfcpp::R_386_TLS_TPOFF32
:
1285 case elfcpp::R_386_TLS_DESC
:
1286 gold_error(_("%s: unexpected reloc %u in object file"),
1287 object
->name().c_str(), r_type
);
1290 // These are initial tls relocs, which are expected when
1292 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1293 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1294 case elfcpp::R_386_TLS_DESC_CALL
:
1295 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1296 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1297 case elfcpp::R_386_TLS_IE
: // Initial-exec
1298 case elfcpp::R_386_TLS_IE_32
:
1299 case elfcpp::R_386_TLS_GOTIE
:
1300 case elfcpp::R_386_TLS_LE
: // Local-exec
1301 case elfcpp::R_386_TLS_LE_32
:
1303 const bool is_final
= gsym
->final_value_is_known();
1304 const tls::Tls_optimization optimized_type
1305 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1308 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1309 if (optimized_type
== tls::TLSOPT_NONE
)
1311 // Create a pair of GOT entries for the module index and
1312 // dtv-relative offset.
1313 Output_data_got
<32, false>* got
1314 = target
->got_section(symtab
, layout
);
1315 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1316 target
->rel_dyn_section(layout
),
1317 elfcpp::R_386_TLS_DTPMOD32
,
1318 elfcpp::R_386_TLS_DTPOFF32
);
1320 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1322 // Create a GOT entry for the tp-relative offset.
1323 Output_data_got
<32, false>* got
1324 = target
->got_section(symtab
, layout
);
1325 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1326 target
->rel_dyn_section(layout
),
1327 elfcpp::R_386_TLS_TPOFF
);
1329 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1330 unsupported_reloc_global(object
, r_type
, gsym
);
1333 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1334 target
->define_tls_base_symbol(symtab
, layout
);
1335 if (optimized_type
== tls::TLSOPT_NONE
)
1337 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1338 Output_data_got
<32, false>* got
1339 = target
->got_section(symtab
, layout
);
1340 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
,
1341 target
->rel_dyn_section(layout
),
1342 elfcpp::R_386_TLS_DESC
, 0);
1344 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1346 // Create a GOT entry for the tp-relative offset.
1347 Output_data_got
<32, false>* got
1348 = target
->got_section(symtab
, layout
);
1349 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1350 target
->rel_dyn_section(layout
),
1351 elfcpp::R_386_TLS_TPOFF
);
1353 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1354 unsupported_reloc_global(object
, r_type
, gsym
);
1357 case elfcpp::R_386_TLS_DESC_CALL
:
1360 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1361 if (optimized_type
== tls::TLSOPT_NONE
)
1363 // Create a GOT entry for the module index.
1364 target
->got_mod_index_entry(symtab
, layout
, object
);
1366 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1367 unsupported_reloc_global(object
, r_type
, gsym
);
1370 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1373 case elfcpp::R_386_TLS_IE
: // Initial-exec
1374 case elfcpp::R_386_TLS_IE_32
:
1375 case elfcpp::R_386_TLS_GOTIE
:
1376 layout
->set_has_static_tls();
1377 if (optimized_type
== tls::TLSOPT_NONE
)
1379 // For the R_386_TLS_IE relocation, we need to create a
1380 // dynamic relocation when building a shared library.
1381 if (r_type
== elfcpp::R_386_TLS_IE
1382 && parameters
->options().shared())
1384 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1385 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1386 output_section
, object
,
1388 reloc
.get_r_offset());
1390 // Create a GOT entry for the tp-relative offset.
1391 Output_data_got
<32, false>* got
1392 = target
->got_section(symtab
, layout
);
1393 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1394 ? elfcpp::R_386_TLS_TPOFF32
1395 : elfcpp::R_386_TLS_TPOFF
);
1396 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1397 ? GOT_TYPE_TLS_OFFSET
1398 : GOT_TYPE_TLS_NOFFSET
);
1399 got
->add_global_with_rel(gsym
, got_type
,
1400 target
->rel_dyn_section(layout
),
1403 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1404 unsupported_reloc_global(object
, r_type
, gsym
);
1407 case elfcpp::R_386_TLS_LE
: // Local-exec
1408 case elfcpp::R_386_TLS_LE_32
:
1409 layout
->set_has_static_tls();
1410 if (parameters
->options().shared())
1412 // We need to create a dynamic relocation.
1413 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1414 ? elfcpp::R_386_TLS_TPOFF32
1415 : elfcpp::R_386_TLS_TPOFF
);
1416 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1417 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1418 data_shndx
, reloc
.get_r_offset());
1428 case elfcpp::R_386_32PLT
:
1429 case elfcpp::R_386_TLS_GD_32
:
1430 case elfcpp::R_386_TLS_GD_PUSH
:
1431 case elfcpp::R_386_TLS_GD_CALL
:
1432 case elfcpp::R_386_TLS_GD_POP
:
1433 case elfcpp::R_386_TLS_LDM_32
:
1434 case elfcpp::R_386_TLS_LDM_PUSH
:
1435 case elfcpp::R_386_TLS_LDM_CALL
:
1436 case elfcpp::R_386_TLS_LDM_POP
:
1437 case elfcpp::R_386_USED_BY_INTEL_200
:
1439 unsupported_reloc_global(object
, r_type
, gsym
);
1444 // Scan relocations for a section.
1447 Target_i386::scan_relocs(const General_options
& options
,
1448 Symbol_table
* symtab
,
1450 Sized_relobj
<32, false>* object
,
1451 unsigned int data_shndx
,
1452 unsigned int sh_type
,
1453 const unsigned char* prelocs
,
1455 Output_section
* output_section
,
1456 bool needs_special_offset_handling
,
1457 size_t local_symbol_count
,
1458 const unsigned char* plocal_symbols
)
1460 if (sh_type
== elfcpp::SHT_RELA
)
1462 gold_error(_("%s: unsupported RELA reloc section"),
1463 object
->name().c_str());
1467 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1478 needs_special_offset_handling
,
1483 // Finalize the sections.
1486 Target_i386::do_finalize_sections(Layout
* layout
)
1488 // Fill in some more dynamic tags.
1489 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1492 if (this->got_plt_
!= NULL
)
1493 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1495 if (this->plt_
!= NULL
)
1497 const Output_data
* od
= this->plt_
->rel_plt();
1498 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1499 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1500 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
1503 if (this->rel_dyn_
!= NULL
)
1505 const Output_data
* od
= this->rel_dyn_
;
1506 odyn
->add_section_address(elfcpp::DT_REL
, od
);
1507 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
1508 odyn
->add_constant(elfcpp::DT_RELENT
,
1509 elfcpp::Elf_sizes
<32>::rel_size
);
1512 if (!parameters
->options().shared())
1514 // The value of the DT_DEBUG tag is filled in by the dynamic
1515 // linker at run time, and used by the debugger.
1516 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1520 // Emit any relocs we saved in an attempt to avoid generating COPY
1522 if (this->copy_relocs_
.any_saved_relocs())
1523 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1526 // Return whether a direct absolute static relocation needs to be applied.
1527 // In cases where Scan::local() or Scan::global() has created
1528 // a dynamic relocation other than R_386_RELATIVE, the addend
1529 // of the relocation is carried in the data, and we must not
1530 // apply the static relocation.
1533 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1537 // For local symbols, we will have created a non-RELATIVE dynamic
1538 // relocation only if (a) the output is position independent,
1539 // (b) the relocation is absolute (not pc- or segment-relative), and
1540 // (c) the relocation is not 32 bits wide.
1542 return !(parameters
->options().output_is_position_independent()
1543 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1546 // For global symbols, we use the same helper routines used in the
1547 // scan pass. If we did not create a dynamic relocation, or if we
1548 // created a RELATIVE dynamic relocation, we should apply the static
1550 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1551 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1552 && gsym
->can_use_relative_reloc(ref_flags
1553 & Symbol::FUNCTION_CALL
);
1554 return !has_dyn
|| is_rel
;
1557 // Perform a relocation.
1560 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1561 Target_i386
* target
,
1563 const elfcpp::Rel
<32, false>& rel
,
1564 unsigned int r_type
,
1565 const Sized_symbol
<32>* gsym
,
1566 const Symbol_value
<32>* psymval
,
1567 unsigned char* view
,
1568 elfcpp::Elf_types
<32>::Elf_Addr address
,
1569 section_size_type view_size
)
1571 if (this->skip_call_tls_get_addr_
)
1573 if (r_type
!= elfcpp::R_386_PLT32
1575 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1576 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1577 _("missing expected TLS relocation"));
1580 this->skip_call_tls_get_addr_
= false;
1585 // Pick the value to use for symbols defined in shared objects.
1586 Symbol_value
<32> symval
;
1587 bool is_nonpic
= (r_type
== elfcpp::R_386_PC8
1588 || r_type
== elfcpp::R_386_PC16
1589 || r_type
== elfcpp::R_386_PC32
);
1591 && (gsym
->is_from_dynobj()
1592 || (parameters
->options().shared()
1593 && (gsym
->is_undefined() || gsym
->is_preemptible())))
1594 && gsym
->has_plt_offset()
1595 && (!is_nonpic
|| !parameters
->options().shared()))
1597 symval
.set_output_value(target
->plt_section()->address()
1598 + gsym
->plt_offset());
1602 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1604 // Get the GOT offset if needed.
1605 // The GOT pointer points to the end of the GOT section.
1606 // We need to subtract the size of the GOT section to get
1607 // the actual offset to use in the relocation.
1608 bool have_got_offset
= false;
1609 unsigned int got_offset
= 0;
1612 case elfcpp::R_386_GOT32
:
1615 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1616 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1617 - target
->got_size());
1621 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1622 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1623 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1624 - target
->got_size());
1626 have_got_offset
= true;
1635 case elfcpp::R_386_NONE
:
1636 case elfcpp::R_386_GNU_VTINHERIT
:
1637 case elfcpp::R_386_GNU_VTENTRY
:
1640 case elfcpp::R_386_32
:
1641 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true))
1642 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1645 case elfcpp::R_386_PC32
:
1647 int ref_flags
= Symbol::NON_PIC_REF
;
1648 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1649 ref_flags
|= Symbol::FUNCTION_CALL
;
1650 if (should_apply_static_reloc(gsym
, ref_flags
, true))
1651 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1655 case elfcpp::R_386_16
:
1656 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1657 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1660 case elfcpp::R_386_PC16
:
1662 int ref_flags
= Symbol::NON_PIC_REF
;
1663 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1664 ref_flags
|= Symbol::FUNCTION_CALL
;
1665 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1666 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1670 case elfcpp::R_386_8
:
1671 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1672 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1675 case elfcpp::R_386_PC8
:
1677 int ref_flags
= Symbol::NON_PIC_REF
;
1678 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1679 ref_flags
|= Symbol::FUNCTION_CALL
;
1680 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1681 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1685 case elfcpp::R_386_PLT32
:
1686 gold_assert(gsym
== NULL
1687 || gsym
->has_plt_offset()
1688 || gsym
->final_value_is_known()
1689 || (gsym
->is_defined()
1690 && !gsym
->is_from_dynobj()
1691 && !gsym
->is_preemptible()));
1692 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1695 case elfcpp::R_386_GOT32
:
1696 gold_assert(have_got_offset
);
1697 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1700 case elfcpp::R_386_GOTOFF
:
1702 elfcpp::Elf_types
<32>::Elf_Addr value
;
1703 value
= (psymval
->value(object
, 0)
1704 - target
->got_plt_section()->address());
1705 Relocate_functions
<32, false>::rel32(view
, value
);
1709 case elfcpp::R_386_GOTPC
:
1711 elfcpp::Elf_types
<32>::Elf_Addr value
;
1712 value
= target
->got_plt_section()->address();
1713 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1717 case elfcpp::R_386_COPY
:
1718 case elfcpp::R_386_GLOB_DAT
:
1719 case elfcpp::R_386_JUMP_SLOT
:
1720 case elfcpp::R_386_RELATIVE
:
1721 // These are outstanding tls relocs, which are unexpected when
1723 case elfcpp::R_386_TLS_TPOFF
:
1724 case elfcpp::R_386_TLS_DTPMOD32
:
1725 case elfcpp::R_386_TLS_DTPOFF32
:
1726 case elfcpp::R_386_TLS_TPOFF32
:
1727 case elfcpp::R_386_TLS_DESC
:
1728 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1729 _("unexpected reloc %u in object file"),
1733 // These are initial tls relocs, which are expected when
1735 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1736 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1737 case elfcpp::R_386_TLS_DESC_CALL
:
1738 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1739 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1740 case elfcpp::R_386_TLS_IE
: // Initial-exec
1741 case elfcpp::R_386_TLS_IE_32
:
1742 case elfcpp::R_386_TLS_GOTIE
:
1743 case elfcpp::R_386_TLS_LE
: // Local-exec
1744 case elfcpp::R_386_TLS_LE_32
:
1745 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1746 view
, address
, view_size
);
1749 case elfcpp::R_386_32PLT
:
1750 case elfcpp::R_386_TLS_GD_32
:
1751 case elfcpp::R_386_TLS_GD_PUSH
:
1752 case elfcpp::R_386_TLS_GD_CALL
:
1753 case elfcpp::R_386_TLS_GD_POP
:
1754 case elfcpp::R_386_TLS_LDM_32
:
1755 case elfcpp::R_386_TLS_LDM_PUSH
:
1756 case elfcpp::R_386_TLS_LDM_CALL
:
1757 case elfcpp::R_386_TLS_LDM_POP
:
1758 case elfcpp::R_386_USED_BY_INTEL_200
:
1760 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1761 _("unsupported reloc %u"),
1769 // Perform a TLS relocation.
1772 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1773 Target_i386
* target
,
1775 const elfcpp::Rel
<32, false>& rel
,
1776 unsigned int r_type
,
1777 const Sized_symbol
<32>* gsym
,
1778 const Symbol_value
<32>* psymval
,
1779 unsigned char* view
,
1780 elfcpp::Elf_types
<32>::Elf_Addr
,
1781 section_size_type view_size
)
1783 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1785 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1787 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1789 const bool is_final
=
1791 ? !parameters
->options().output_is_position_independent()
1792 : gsym
->final_value_is_known());
1793 const tls::Tls_optimization optimized_type
1794 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1797 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1798 if (optimized_type
== tls::TLSOPT_TO_LE
)
1800 gold_assert(tls_segment
!= NULL
);
1801 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1802 rel
, r_type
, value
, view
,
1808 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1809 ? GOT_TYPE_TLS_NOFFSET
1810 : GOT_TYPE_TLS_PAIR
);
1811 unsigned int got_offset
;
1814 gold_assert(gsym
->has_got_offset(got_type
));
1815 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1819 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1820 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1821 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1822 - target
->got_size());
1824 if (optimized_type
== tls::TLSOPT_TO_IE
)
1826 gold_assert(tls_segment
!= NULL
);
1827 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1828 got_offset
, view
, view_size
);
1831 else if (optimized_type
== tls::TLSOPT_NONE
)
1833 // Relocate the field with the offset of the pair of GOT
1835 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1839 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1840 _("unsupported reloc %u"),
1844 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1845 case elfcpp::R_386_TLS_DESC_CALL
:
1846 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1847 if (optimized_type
== tls::TLSOPT_TO_LE
)
1849 gold_assert(tls_segment
!= NULL
);
1850 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
1851 rel
, r_type
, value
, view
,
1857 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1858 ? GOT_TYPE_TLS_NOFFSET
1859 : GOT_TYPE_TLS_DESC
);
1860 unsigned int got_offset
;
1863 gold_assert(gsym
->has_got_offset(got_type
));
1864 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1868 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1869 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1870 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1871 - target
->got_size());
1873 if (optimized_type
== tls::TLSOPT_TO_IE
)
1875 gold_assert(tls_segment
!= NULL
);
1876 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1877 got_offset
, view
, view_size
);
1880 else if (optimized_type
== tls::TLSOPT_NONE
)
1882 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
1884 // Relocate the field with the offset of the pair of GOT
1886 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1891 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1892 _("unsupported reloc %u"),
1896 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1897 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
1899 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1900 _("both SUN and GNU model "
1901 "TLS relocations"));
1904 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1905 if (optimized_type
== tls::TLSOPT_TO_LE
)
1907 gold_assert(tls_segment
!= NULL
);
1908 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1909 value
, view
, view_size
);
1912 else if (optimized_type
== tls::TLSOPT_NONE
)
1914 // Relocate the field with the offset of the GOT entry for
1915 // the module index.
1916 unsigned int got_offset
;
1917 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
1918 - target
->got_size());
1919 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1922 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1923 _("unsupported reloc %u"),
1927 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1928 // This reloc can appear in debugging sections, in which case we
1929 // won't see the TLS_LDM reloc. The local_dynamic_type field
1931 if (optimized_type
== tls::TLSOPT_TO_LE
1932 && this->local_dynamic_type_
!= LOCAL_DYNAMIC_NONE
)
1934 gold_assert(tls_segment
!= NULL
);
1935 value
-= tls_segment
->memsz();
1937 Relocate_functions
<32, false>::rel32(view
, value
);
1940 case elfcpp::R_386_TLS_IE
: // Initial-exec
1941 case elfcpp::R_386_TLS_GOTIE
:
1942 case elfcpp::R_386_TLS_IE_32
:
1943 if (optimized_type
== tls::TLSOPT_TO_LE
)
1945 gold_assert(tls_segment
!= NULL
);
1946 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1947 rel
, r_type
, value
, view
,
1951 else if (optimized_type
== tls::TLSOPT_NONE
)
1953 // Relocate the field with the offset of the GOT entry for
1954 // the tp-relative offset of the symbol.
1955 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1956 ? GOT_TYPE_TLS_OFFSET
1957 : GOT_TYPE_TLS_NOFFSET
);
1958 unsigned int got_offset
;
1961 gold_assert(gsym
->has_got_offset(got_type
));
1962 got_offset
= gsym
->got_offset(got_type
);
1966 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1967 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1968 got_offset
= object
->local_got_offset(r_sym
, got_type
);
1970 // For the R_386_TLS_IE relocation, we need to apply the
1971 // absolute address of the GOT entry.
1972 if (r_type
== elfcpp::R_386_TLS_IE
)
1973 got_offset
+= target
->got_plt_section()->address();
1974 // All GOT offsets are relative to the end of the GOT.
1975 got_offset
-= target
->got_size();
1976 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1979 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1980 _("unsupported reloc %u"),
1984 case elfcpp::R_386_TLS_LE
: // Local-exec
1985 // If we're creating a shared library, a dynamic relocation will
1986 // have been created for this location, so do not apply it now.
1987 if (!parameters
->options().shared())
1989 gold_assert(tls_segment
!= NULL
);
1990 value
-= tls_segment
->memsz();
1991 Relocate_functions
<32, false>::rel32(view
, value
);
1995 case elfcpp::R_386_TLS_LE_32
:
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() - value
;
2002 Relocate_functions
<32, false>::rel32(view
, value
);
2008 // Do a relocation in which we convert a TLS General-Dynamic to a
2012 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2014 Output_segment
* tls_segment
,
2015 const elfcpp::Rel
<32, false>& rel
,
2017 elfcpp::Elf_types
<32>::Elf_Addr value
,
2018 unsigned char* view
,
2019 section_size_type view_size
)
2021 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2022 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2023 // leal foo(%reg),%eax; call ___tls_get_addr
2024 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2026 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2027 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2029 unsigned char op1
= view
[-1];
2030 unsigned char op2
= view
[-2];
2032 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2033 op2
== 0x8d || op2
== 0x04);
2034 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2040 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2041 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2042 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2043 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2044 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2048 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2049 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2050 if (rel
.get_r_offset() + 9 < view_size
2053 // There is a trailing nop. Use the size byte subl.
2054 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2059 // Use the five byte subl.
2060 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2064 value
= tls_segment
->memsz() - value
;
2065 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2067 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2069 this->skip_call_tls_get_addr_
= true;
2072 // Do a relocation in which we convert a TLS General-Dynamic to an
2076 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2079 const elfcpp::Rel
<32, false>& rel
,
2081 elfcpp::Elf_types
<32>::Elf_Addr value
,
2082 unsigned char* view
,
2083 section_size_type view_size
)
2085 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2086 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2088 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2089 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2091 unsigned char op1
= view
[-1];
2092 unsigned char op2
= view
[-2];
2094 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2095 op2
== 0x8d || op2
== 0x04);
2096 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2100 // FIXME: For now, support only the first (SIB) form.
2101 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2105 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2106 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2107 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2108 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2109 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2113 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2114 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2115 if (rel
.get_r_offset() + 9 < view_size
2118 // FIXME: This is not the right instruction sequence.
2119 // There is a trailing nop. Use the size byte subl.
2120 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2125 // FIXME: This is not the right instruction sequence.
2126 // Use the five byte subl.
2127 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2131 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2133 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2135 this->skip_call_tls_get_addr_
= true;
2138 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2139 // General-Dynamic to a Local-Exec.
2142 Target_i386::Relocate::tls_desc_gd_to_le(
2143 const Relocate_info
<32, false>* relinfo
,
2145 Output_segment
* tls_segment
,
2146 const elfcpp::Rel
<32, false>& rel
,
2147 unsigned int r_type
,
2148 elfcpp::Elf_types
<32>::Elf_Addr value
,
2149 unsigned char* view
,
2150 section_size_type view_size
)
2152 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2154 // leal foo@TLSDESC(%ebx), %eax
2155 // ==> leal foo@NTPOFF, %eax
2156 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2157 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2158 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2159 view
[-2] == 0x8d && view
[-1] == 0x83);
2161 value
-= tls_segment
->memsz();
2162 Relocate_functions
<32, false>::rel32(view
, value
);
2166 // call *foo@TLSCALL(%eax)
2168 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2169 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2170 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2171 view
[0] == 0xff && view
[1] == 0x10);
2177 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2178 // General-Dynamic to an Initial-Exec.
2181 Target_i386::Relocate::tls_desc_gd_to_ie(
2182 const Relocate_info
<32, false>* relinfo
,
2185 const elfcpp::Rel
<32, false>& rel
,
2186 unsigned int r_type
,
2187 elfcpp::Elf_types
<32>::Elf_Addr value
,
2188 unsigned char* view
,
2189 section_size_type view_size
)
2191 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2193 // leal foo@TLSDESC(%ebx), %eax
2194 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2195 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2196 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2197 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2198 view
[-2] == 0x8d && view
[-1] == 0x83);
2200 Relocate_functions
<32, false>::rel32(view
, value
);
2204 // call *foo@TLSCALL(%eax)
2206 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2207 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2208 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2209 view
[0] == 0xff && view
[1] == 0x10);
2215 // Do a relocation in which we convert a TLS Local-Dynamic to a
2219 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2222 const elfcpp::Rel
<32, false>& rel
,
2224 elfcpp::Elf_types
<32>::Elf_Addr
,
2225 unsigned char* view
,
2226 section_size_type view_size
)
2228 // leal foo(%reg), %eax; call ___tls_get_addr
2229 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2231 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2232 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2234 // FIXME: Does this test really always pass?
2235 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2236 view
[-2] == 0x8d && view
[-1] == 0x83);
2238 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2240 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2242 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2244 this->skip_call_tls_get_addr_
= true;
2247 // Do a relocation in which we convert a TLS Initial-Exec to a
2251 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2253 Output_segment
* tls_segment
,
2254 const elfcpp::Rel
<32, false>& rel
,
2255 unsigned int r_type
,
2256 elfcpp::Elf_types
<32>::Elf_Addr value
,
2257 unsigned char* view
,
2258 section_size_type view_size
)
2260 // We have to actually change the instructions, which means that we
2261 // need to examine the opcodes to figure out which instruction we
2263 if (r_type
== elfcpp::R_386_TLS_IE
)
2265 // movl %gs:XX,%eax ==> movl $YY,%eax
2266 // movl %gs:XX,%reg ==> movl $YY,%reg
2267 // addl %gs:XX,%reg ==> addl $YY,%reg
2268 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2269 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2271 unsigned char op1
= view
[-1];
2274 // movl XX,%eax ==> movl $YY,%eax
2279 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2281 unsigned char op2
= view
[-2];
2284 // movl XX,%reg ==> movl $YY,%reg
2285 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2286 (op1
& 0xc7) == 0x05);
2288 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2290 else if (op2
== 0x03)
2292 // addl XX,%reg ==> addl $YY,%reg
2293 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2294 (op1
& 0xc7) == 0x05);
2296 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2299 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2304 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2305 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2306 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2307 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2308 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2310 unsigned char op1
= view
[-1];
2311 unsigned char op2
= view
[-2];
2312 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2313 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2316 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2318 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2320 else if (op2
== 0x2b)
2322 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2324 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2326 else if (op2
== 0x03)
2328 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2330 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2333 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2336 value
= tls_segment
->memsz() - value
;
2337 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2340 Relocate_functions
<32, false>::rel32(view
, value
);
2343 // Relocate section data.
2346 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2347 unsigned int sh_type
,
2348 const unsigned char* prelocs
,
2350 Output_section
* output_section
,
2351 bool needs_special_offset_handling
,
2352 unsigned char* view
,
2353 elfcpp::Elf_types
<32>::Elf_Addr address
,
2354 section_size_type view_size
)
2356 gold_assert(sh_type
== elfcpp::SHT_REL
);
2358 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2359 Target_i386::Relocate
>(
2365 needs_special_offset_handling
,
2371 // Return the size of a relocation while scanning during a relocatable
2375 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2376 unsigned int r_type
,
2381 case elfcpp::R_386_NONE
:
2382 case elfcpp::R_386_GNU_VTINHERIT
:
2383 case elfcpp::R_386_GNU_VTENTRY
:
2384 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2385 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2386 case elfcpp::R_386_TLS_DESC_CALL
:
2387 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2388 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2389 case elfcpp::R_386_TLS_IE
: // Initial-exec
2390 case elfcpp::R_386_TLS_IE_32
:
2391 case elfcpp::R_386_TLS_GOTIE
:
2392 case elfcpp::R_386_TLS_LE
: // Local-exec
2393 case elfcpp::R_386_TLS_LE_32
:
2396 case elfcpp::R_386_32
:
2397 case elfcpp::R_386_PC32
:
2398 case elfcpp::R_386_GOT32
:
2399 case elfcpp::R_386_PLT32
:
2400 case elfcpp::R_386_GOTOFF
:
2401 case elfcpp::R_386_GOTPC
:
2404 case elfcpp::R_386_16
:
2405 case elfcpp::R_386_PC16
:
2408 case elfcpp::R_386_8
:
2409 case elfcpp::R_386_PC8
:
2412 // These are relocations which should only be seen by the
2413 // dynamic linker, and should never be seen here.
2414 case elfcpp::R_386_COPY
:
2415 case elfcpp::R_386_GLOB_DAT
:
2416 case elfcpp::R_386_JUMP_SLOT
:
2417 case elfcpp::R_386_RELATIVE
:
2418 case elfcpp::R_386_TLS_TPOFF
:
2419 case elfcpp::R_386_TLS_DTPMOD32
:
2420 case elfcpp::R_386_TLS_DTPOFF32
:
2421 case elfcpp::R_386_TLS_TPOFF32
:
2422 case elfcpp::R_386_TLS_DESC
:
2423 object
->error(_("unexpected reloc %u in object file"), r_type
);
2426 case elfcpp::R_386_32PLT
:
2427 case elfcpp::R_386_TLS_GD_32
:
2428 case elfcpp::R_386_TLS_GD_PUSH
:
2429 case elfcpp::R_386_TLS_GD_CALL
:
2430 case elfcpp::R_386_TLS_GD_POP
:
2431 case elfcpp::R_386_TLS_LDM_32
:
2432 case elfcpp::R_386_TLS_LDM_PUSH
:
2433 case elfcpp::R_386_TLS_LDM_CALL
:
2434 case elfcpp::R_386_TLS_LDM_POP
:
2435 case elfcpp::R_386_USED_BY_INTEL_200
:
2437 object
->error(_("unsupported reloc %u in object file"), r_type
);
2442 // Scan the relocs during a relocatable link.
2445 Target_i386::scan_relocatable_relocs(const General_options
& options
,
2446 Symbol_table
* symtab
,
2448 Sized_relobj
<32, false>* object
,
2449 unsigned int data_shndx
,
2450 unsigned int sh_type
,
2451 const unsigned char* prelocs
,
2453 Output_section
* output_section
,
2454 bool needs_special_offset_handling
,
2455 size_t local_symbol_count
,
2456 const unsigned char* plocal_symbols
,
2457 Relocatable_relocs
* rr
)
2459 gold_assert(sh_type
== elfcpp::SHT_REL
);
2461 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2462 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2464 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2465 Scan_relocatable_relocs
>(
2474 needs_special_offset_handling
,
2480 // Relocate a section during a relocatable link.
2483 Target_i386::relocate_for_relocatable(
2484 const Relocate_info
<32, false>* relinfo
,
2485 unsigned int sh_type
,
2486 const unsigned char* prelocs
,
2488 Output_section
* output_section
,
2489 off_t offset_in_output_section
,
2490 const Relocatable_relocs
* rr
,
2491 unsigned char* view
,
2492 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2493 section_size_type view_size
,
2494 unsigned char* reloc_view
,
2495 section_size_type reloc_view_size
)
2497 gold_assert(sh_type
== elfcpp::SHT_REL
);
2499 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2504 offset_in_output_section
,
2513 // Return the value to use for a dynamic which requires special
2514 // treatment. This is how we support equality comparisons of function
2515 // pointers across shared library boundaries, as described in the
2516 // processor specific ABI supplement.
2519 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2521 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2522 return this->plt_section()->address() + gsym
->plt_offset();
2525 // Return a string used to fill a code section with nops to take up
2526 // the specified length.
2529 Target_i386::do_code_fill(section_size_type length
) const
2533 // Build a jmp instruction to skip over the bytes.
2534 unsigned char jmp
[5];
2536 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2537 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2538 + std::string(length
- 5, '\0'));
2541 // Nop sequences of various lengths.
2542 const char nop1
[1] = { 0x90 }; // nop
2543 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2544 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2545 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2546 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2547 0x00 }; // leal 0(%esi,1),%esi
2548 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2550 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2552 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2553 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2554 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2555 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2557 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2558 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2560 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2561 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2563 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2564 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2565 0x00, 0x00, 0x00, 0x00 };
2566 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2567 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2568 0x27, 0x00, 0x00, 0x00,
2570 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2571 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2572 0xbc, 0x27, 0x00, 0x00,
2574 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2575 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2576 0x90, 0x90, 0x90, 0x90,
2579 const char* nops
[16] = {
2581 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2582 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2585 return std::string(nops
[length
], length
);
2588 // The selector for i386 object files.
2590 class Target_selector_i386
: public Target_selector
2593 Target_selector_i386()
2594 : Target_selector(elfcpp::EM_386
, 32, false, "elf32-i386")
2598 do_instantiate_target()
2599 { return new Target_i386(); }
2602 Target_selector_i386 target_selector_i386
;
2604 } // End anonymous namespace.