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();
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();
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 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
886 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
887 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
888 data_shndx
, reloc
.get_r_offset());
892 gold_assert(lsym
.get_st_value() == 0);
893 rel_dyn
->add_local_section(object
, lsym
.get_st_shndx(),
894 r_type
, output_section
,
895 data_shndx
, reloc
.get_r_offset());
900 case elfcpp::R_386_PC32
:
901 case elfcpp::R_386_PC16
:
902 case elfcpp::R_386_PC8
:
905 case elfcpp::R_386_PLT32
:
906 // Since we know this is a local symbol, we can handle this as a
910 case elfcpp::R_386_GOTOFF
:
911 case elfcpp::R_386_GOTPC
:
912 // We need a GOT section.
913 target
->got_section(symtab
, layout
);
916 case elfcpp::R_386_GOT32
:
918 // The symbol requires a GOT entry.
919 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
920 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
921 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
923 // If we are generating a shared object, we need to add a
924 // dynamic RELATIVE relocation for this symbol's GOT entry.
925 if (parameters
->options().output_is_position_independent())
927 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
928 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
929 rel_dyn
->add_local_relative(
930 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
931 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
937 // These are relocations which should only be seen by the
938 // dynamic linker, and should never be seen here.
939 case elfcpp::R_386_COPY
:
940 case elfcpp::R_386_GLOB_DAT
:
941 case elfcpp::R_386_JUMP_SLOT
:
942 case elfcpp::R_386_RELATIVE
:
943 case elfcpp::R_386_TLS_TPOFF
:
944 case elfcpp::R_386_TLS_DTPMOD32
:
945 case elfcpp::R_386_TLS_DTPOFF32
:
946 case elfcpp::R_386_TLS_TPOFF32
:
947 case elfcpp::R_386_TLS_DESC
:
948 gold_error(_("%s: unexpected reloc %u in object file"),
949 object
->name().c_str(), r_type
);
952 // These are initial TLS relocs, which are expected when
954 case elfcpp::R_386_TLS_GD
: // Global-dynamic
955 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
956 case elfcpp::R_386_TLS_DESC_CALL
:
957 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
958 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
959 case elfcpp::R_386_TLS_IE
: // Initial-exec
960 case elfcpp::R_386_TLS_IE_32
:
961 case elfcpp::R_386_TLS_GOTIE
:
962 case elfcpp::R_386_TLS_LE
: // Local-exec
963 case elfcpp::R_386_TLS_LE_32
:
965 bool output_is_shared
= parameters
->options().shared();
966 const tls::Tls_optimization optimized_type
967 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
970 case elfcpp::R_386_TLS_GD
: // Global-dynamic
971 if (optimized_type
== tls::TLSOPT_NONE
)
973 // Create a pair of GOT entries for the module index and
974 // dtv-relative offset.
975 Output_data_got
<32, false>* got
976 = target
->got_section(symtab
, layout
);
977 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
978 got
->add_local_pair_with_rel(object
, r_sym
,
981 target
->rel_dyn_section(layout
),
982 elfcpp::R_386_TLS_DTPMOD32
, 0);
984 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
985 unsupported_reloc_local(object
, r_type
);
988 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
989 target
->define_tls_base_symbol(symtab
, layout
);
990 if (optimized_type
== tls::TLSOPT_NONE
)
992 // Create a double GOT entry with an R_386_TLS_DESC reloc.
993 Output_data_got
<32, false>* got
994 = target
->got_section(symtab
, layout
);
995 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
996 got
->add_local_pair_with_rel(object
, r_sym
,
999 target
->rel_dyn_section(layout
),
1000 elfcpp::R_386_TLS_DESC
, 0);
1002 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1003 unsupported_reloc_local(object
, r_type
);
1006 case elfcpp::R_386_TLS_DESC_CALL
:
1009 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1010 if (optimized_type
== tls::TLSOPT_NONE
)
1012 // Create a GOT entry for the module index.
1013 target
->got_mod_index_entry(symtab
, layout
, object
);
1015 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1016 unsupported_reloc_local(object
, r_type
);
1019 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1022 case elfcpp::R_386_TLS_IE
: // Initial-exec
1023 case elfcpp::R_386_TLS_IE_32
:
1024 case elfcpp::R_386_TLS_GOTIE
:
1025 layout
->set_has_static_tls();
1026 if (optimized_type
== tls::TLSOPT_NONE
)
1028 // For the R_386_TLS_IE relocation, we need to create a
1029 // dynamic relocation when building a shared library.
1030 if (r_type
== elfcpp::R_386_TLS_IE
1031 && parameters
->options().shared())
1033 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1035 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1036 rel_dyn
->add_local_relative(object
, r_sym
,
1037 elfcpp::R_386_RELATIVE
,
1038 output_section
, data_shndx
,
1039 reloc
.get_r_offset());
1041 // Create a GOT entry for the tp-relative offset.
1042 Output_data_got
<32, false>* got
1043 = target
->got_section(symtab
, layout
);
1044 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1045 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1046 ? elfcpp::R_386_TLS_TPOFF32
1047 : elfcpp::R_386_TLS_TPOFF
);
1048 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1049 ? GOT_TYPE_TLS_OFFSET
1050 : GOT_TYPE_TLS_NOFFSET
);
1051 got
->add_local_with_rel(object
, r_sym
, got_type
,
1052 target
->rel_dyn_section(layout
),
1055 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1056 unsupported_reloc_local(object
, r_type
);
1059 case elfcpp::R_386_TLS_LE
: // Local-exec
1060 case elfcpp::R_386_TLS_LE_32
:
1061 layout
->set_has_static_tls();
1062 if (output_is_shared
)
1064 // We need to create a dynamic relocation.
1065 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1066 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1067 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1068 ? elfcpp::R_386_TLS_TPOFF32
1069 : elfcpp::R_386_TLS_TPOFF
);
1070 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1071 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1072 data_shndx
, reloc
.get_r_offset());
1082 case elfcpp::R_386_32PLT
:
1083 case elfcpp::R_386_TLS_GD_32
:
1084 case elfcpp::R_386_TLS_GD_PUSH
:
1085 case elfcpp::R_386_TLS_GD_CALL
:
1086 case elfcpp::R_386_TLS_GD_POP
:
1087 case elfcpp::R_386_TLS_LDM_32
:
1088 case elfcpp::R_386_TLS_LDM_PUSH
:
1089 case elfcpp::R_386_TLS_LDM_CALL
:
1090 case elfcpp::R_386_TLS_LDM_POP
:
1091 case elfcpp::R_386_USED_BY_INTEL_200
:
1093 unsupported_reloc_local(object
, r_type
);
1098 // Report an unsupported relocation against a global symbol.
1101 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1102 unsigned int r_type
,
1105 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1106 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1109 // Scan a relocation for a global symbol.
1112 Target_i386::Scan::global(const General_options
&,
1113 Symbol_table
* symtab
,
1115 Target_i386
* target
,
1116 Sized_relobj
<32, false>* object
,
1117 unsigned int data_shndx
,
1118 Output_section
* output_section
,
1119 const elfcpp::Rel
<32, false>& reloc
,
1120 unsigned int r_type
,
1125 case elfcpp::R_386_NONE
:
1126 case elfcpp::R_386_GNU_VTINHERIT
:
1127 case elfcpp::R_386_GNU_VTENTRY
:
1130 case elfcpp::R_386_32
:
1131 case elfcpp::R_386_16
:
1132 case elfcpp::R_386_8
:
1134 // Make a PLT entry if necessary.
1135 if (gsym
->needs_plt_entry())
1137 target
->make_plt_entry(symtab
, layout
, gsym
);
1138 // Since this is not a PC-relative relocation, we may be
1139 // taking the address of a function. In that case we need to
1140 // set the entry in the dynamic symbol table to the address of
1142 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1143 gsym
->set_needs_dynsym_value();
1145 // Make a dynamic relocation if necessary.
1146 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1148 if (target
->may_need_copy_reloc(gsym
))
1150 target
->copy_reloc(symtab
, layout
, object
,
1151 data_shndx
, output_section
, gsym
, reloc
);
1153 else if (r_type
== elfcpp::R_386_32
1154 && gsym
->can_use_relative_reloc(false))
1156 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1157 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1158 output_section
, object
,
1159 data_shndx
, reloc
.get_r_offset());
1163 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1164 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1165 data_shndx
, reloc
.get_r_offset());
1171 case elfcpp::R_386_PC32
:
1172 case elfcpp::R_386_PC16
:
1173 case elfcpp::R_386_PC8
:
1175 // Make a PLT entry if necessary.
1176 if (gsym
->needs_plt_entry())
1178 // These relocations are used for function calls only in
1179 // non-PIC code. For a 32-bit relocation in a shared library,
1180 // we'll need a text relocation anyway, so we can skip the
1181 // PLT entry and let the dynamic linker bind the call directly
1182 // to the target. For smaller relocations, we should use a
1183 // PLT entry to ensure that the call can reach.
1184 if (!parameters
->options().shared()
1185 || r_type
!= elfcpp::R_386_PC32
)
1186 target
->make_plt_entry(symtab
, layout
, gsym
);
1188 // Make a dynamic relocation if necessary.
1189 int flags
= Symbol::NON_PIC_REF
;
1190 if (gsym
->type() == elfcpp::STT_FUNC
)
1191 flags
|= Symbol::FUNCTION_CALL
;
1192 if (gsym
->needs_dynamic_reloc(flags
))
1194 if (target
->may_need_copy_reloc(gsym
))
1196 target
->copy_reloc(symtab
, layout
, object
,
1197 data_shndx
, output_section
, gsym
, reloc
);
1201 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1202 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1203 data_shndx
, reloc
.get_r_offset());
1209 case elfcpp::R_386_GOT32
:
1211 // The symbol requires a GOT entry.
1212 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1213 if (gsym
->final_value_is_known())
1214 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1217 // If this symbol is not fully resolved, we need to add a
1218 // GOT entry with a dynamic relocation.
1219 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1220 if (gsym
->is_from_dynobj()
1221 || gsym
->is_undefined()
1222 || gsym
->is_preemptible())
1223 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1224 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1227 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1228 rel_dyn
->add_global_relative(
1229 gsym
, elfcpp::R_386_RELATIVE
, got
,
1230 gsym
->got_offset(GOT_TYPE_STANDARD
));
1236 case elfcpp::R_386_PLT32
:
1237 // If the symbol is fully resolved, this is just a PC32 reloc.
1238 // Otherwise we need a PLT entry.
1239 if (gsym
->final_value_is_known())
1241 // If building a shared library, we can also skip the PLT entry
1242 // if the symbol is defined in the output file and is protected
1244 if (gsym
->is_defined()
1245 && !gsym
->is_from_dynobj()
1246 && !gsym
->is_preemptible())
1248 target
->make_plt_entry(symtab
, layout
, gsym
);
1251 case elfcpp::R_386_GOTOFF
:
1252 case elfcpp::R_386_GOTPC
:
1253 // We need a GOT section.
1254 target
->got_section(symtab
, layout
);
1257 // These are relocations which should only be seen by the
1258 // dynamic linker, and should never be seen here.
1259 case elfcpp::R_386_COPY
:
1260 case elfcpp::R_386_GLOB_DAT
:
1261 case elfcpp::R_386_JUMP_SLOT
:
1262 case elfcpp::R_386_RELATIVE
:
1263 case elfcpp::R_386_TLS_TPOFF
:
1264 case elfcpp::R_386_TLS_DTPMOD32
:
1265 case elfcpp::R_386_TLS_DTPOFF32
:
1266 case elfcpp::R_386_TLS_TPOFF32
:
1267 case elfcpp::R_386_TLS_DESC
:
1268 gold_error(_("%s: unexpected reloc %u in object file"),
1269 object
->name().c_str(), r_type
);
1272 // These are initial tls relocs, which are expected when
1274 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1275 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1276 case elfcpp::R_386_TLS_DESC_CALL
:
1277 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1278 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1279 case elfcpp::R_386_TLS_IE
: // Initial-exec
1280 case elfcpp::R_386_TLS_IE_32
:
1281 case elfcpp::R_386_TLS_GOTIE
:
1282 case elfcpp::R_386_TLS_LE
: // Local-exec
1283 case elfcpp::R_386_TLS_LE_32
:
1285 const bool is_final
= gsym
->final_value_is_known();
1286 const tls::Tls_optimization optimized_type
1287 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1290 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1291 if (optimized_type
== tls::TLSOPT_NONE
)
1293 // Create a pair of GOT entries for the module index and
1294 // dtv-relative offset.
1295 Output_data_got
<32, false>* got
1296 = target
->got_section(symtab
, layout
);
1297 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1298 target
->rel_dyn_section(layout
),
1299 elfcpp::R_386_TLS_DTPMOD32
,
1300 elfcpp::R_386_TLS_DTPOFF32
);
1302 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1304 // Create a GOT entry for the tp-relative offset.
1305 Output_data_got
<32, false>* got
1306 = target
->got_section(symtab
, layout
);
1307 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1308 target
->rel_dyn_section(layout
),
1309 elfcpp::R_386_TLS_TPOFF
);
1311 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1312 unsupported_reloc_global(object
, r_type
, gsym
);
1315 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1316 target
->define_tls_base_symbol(symtab
, layout
);
1317 if (optimized_type
== tls::TLSOPT_NONE
)
1319 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1320 Output_data_got
<32, false>* got
1321 = target
->got_section(symtab
, layout
);
1322 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
,
1323 target
->rel_dyn_section(layout
),
1324 elfcpp::R_386_TLS_DESC
, 0);
1326 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1328 // Create a GOT entry for the tp-relative offset.
1329 Output_data_got
<32, false>* got
1330 = target
->got_section(symtab
, layout
);
1331 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1332 target
->rel_dyn_section(layout
),
1333 elfcpp::R_386_TLS_TPOFF
);
1335 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1336 unsupported_reloc_global(object
, r_type
, gsym
);
1339 case elfcpp::R_386_TLS_DESC_CALL
:
1342 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1343 if (optimized_type
== tls::TLSOPT_NONE
)
1345 // Create a GOT entry for the module index.
1346 target
->got_mod_index_entry(symtab
, layout
, object
);
1348 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1349 unsupported_reloc_global(object
, r_type
, gsym
);
1352 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1355 case elfcpp::R_386_TLS_IE
: // Initial-exec
1356 case elfcpp::R_386_TLS_IE_32
:
1357 case elfcpp::R_386_TLS_GOTIE
:
1358 layout
->set_has_static_tls();
1359 if (optimized_type
== tls::TLSOPT_NONE
)
1361 // For the R_386_TLS_IE relocation, we need to create a
1362 // dynamic relocation when building a shared library.
1363 if (r_type
== elfcpp::R_386_TLS_IE
1364 && parameters
->options().shared())
1366 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1367 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1368 output_section
, object
,
1370 reloc
.get_r_offset());
1372 // Create a GOT entry for the tp-relative offset.
1373 Output_data_got
<32, false>* got
1374 = target
->got_section(symtab
, layout
);
1375 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1376 ? elfcpp::R_386_TLS_TPOFF32
1377 : elfcpp::R_386_TLS_TPOFF
);
1378 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1379 ? GOT_TYPE_TLS_OFFSET
1380 : GOT_TYPE_TLS_NOFFSET
);
1381 got
->add_global_with_rel(gsym
, got_type
,
1382 target
->rel_dyn_section(layout
),
1385 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1386 unsupported_reloc_global(object
, r_type
, gsym
);
1389 case elfcpp::R_386_TLS_LE
: // Local-exec
1390 case elfcpp::R_386_TLS_LE_32
:
1391 layout
->set_has_static_tls();
1392 if (parameters
->options().shared())
1394 // We need to create a dynamic relocation.
1395 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1396 ? elfcpp::R_386_TLS_TPOFF32
1397 : elfcpp::R_386_TLS_TPOFF
);
1398 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1399 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1400 data_shndx
, reloc
.get_r_offset());
1410 case elfcpp::R_386_32PLT
:
1411 case elfcpp::R_386_TLS_GD_32
:
1412 case elfcpp::R_386_TLS_GD_PUSH
:
1413 case elfcpp::R_386_TLS_GD_CALL
:
1414 case elfcpp::R_386_TLS_GD_POP
:
1415 case elfcpp::R_386_TLS_LDM_32
:
1416 case elfcpp::R_386_TLS_LDM_PUSH
:
1417 case elfcpp::R_386_TLS_LDM_CALL
:
1418 case elfcpp::R_386_TLS_LDM_POP
:
1419 case elfcpp::R_386_USED_BY_INTEL_200
:
1421 unsupported_reloc_global(object
, r_type
, gsym
);
1426 // Scan relocations for a section.
1429 Target_i386::scan_relocs(const General_options
& options
,
1430 Symbol_table
* symtab
,
1432 Sized_relobj
<32, false>* object
,
1433 unsigned int data_shndx
,
1434 unsigned int sh_type
,
1435 const unsigned char* prelocs
,
1437 Output_section
* output_section
,
1438 bool needs_special_offset_handling
,
1439 size_t local_symbol_count
,
1440 const unsigned char* plocal_symbols
)
1442 if (sh_type
== elfcpp::SHT_RELA
)
1444 gold_error(_("%s: unsupported RELA reloc section"),
1445 object
->name().c_str());
1449 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1460 needs_special_offset_handling
,
1465 // Finalize the sections.
1468 Target_i386::do_finalize_sections(Layout
* layout
)
1470 // Fill in some more dynamic tags.
1471 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1474 if (this->got_plt_
!= NULL
)
1475 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1477 if (this->plt_
!= NULL
)
1479 const Output_data
* od
= this->plt_
->rel_plt();
1480 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1481 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1482 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
1485 if (this->rel_dyn_
!= NULL
)
1487 const Output_data
* od
= this->rel_dyn_
;
1488 odyn
->add_section_address(elfcpp::DT_REL
, od
);
1489 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
1490 odyn
->add_constant(elfcpp::DT_RELENT
,
1491 elfcpp::Elf_sizes
<32>::rel_size
);
1494 if (!parameters
->options().shared())
1496 // The value of the DT_DEBUG tag is filled in by the dynamic
1497 // linker at run time, and used by the debugger.
1498 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1502 // Emit any relocs we saved in an attempt to avoid generating COPY
1504 if (this->copy_relocs_
.any_saved_relocs())
1505 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1508 // Return whether a direct absolute static relocation needs to be applied.
1509 // In cases where Scan::local() or Scan::global() has created
1510 // a dynamic relocation other than R_386_RELATIVE, the addend
1511 // of the relocation is carried in the data, and we must not
1512 // apply the static relocation.
1515 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1519 // For local symbols, we will have created a non-RELATIVE dynamic
1520 // relocation only if (a) the output is position independent,
1521 // (b) the relocation is absolute (not pc- or segment-relative), and
1522 // (c) the relocation is not 32 bits wide.
1524 return !(parameters
->options().output_is_position_independent()
1525 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1528 // For global symbols, we use the same helper routines used in the
1529 // scan pass. If we did not create a dynamic relocation, or if we
1530 // created a RELATIVE dynamic relocation, we should apply the static
1532 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1533 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1534 && gsym
->can_use_relative_reloc(ref_flags
1535 & Symbol::FUNCTION_CALL
);
1536 return !has_dyn
|| is_rel
;
1539 // Perform a relocation.
1542 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1543 Target_i386
* target
,
1545 const elfcpp::Rel
<32, false>& rel
,
1546 unsigned int r_type
,
1547 const Sized_symbol
<32>* gsym
,
1548 const Symbol_value
<32>* psymval
,
1549 unsigned char* view
,
1550 elfcpp::Elf_types
<32>::Elf_Addr address
,
1551 section_size_type view_size
)
1553 if (this->skip_call_tls_get_addr_
)
1555 if (r_type
!= elfcpp::R_386_PLT32
1557 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1558 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1559 _("missing expected TLS relocation"));
1562 this->skip_call_tls_get_addr_
= false;
1567 // Pick the value to use for symbols defined in shared objects.
1568 Symbol_value
<32> symval
;
1569 bool is_nonpic
= (r_type
== elfcpp::R_386_PC8
1570 || r_type
== elfcpp::R_386_PC16
1571 || r_type
== elfcpp::R_386_PC32
);
1573 && (gsym
->is_from_dynobj()
1574 || (parameters
->options().shared()
1575 && (gsym
->is_undefined() || gsym
->is_preemptible())))
1576 && gsym
->has_plt_offset()
1577 && (!is_nonpic
|| !parameters
->options().shared()))
1579 symval
.set_output_value(target
->plt_section()->address()
1580 + gsym
->plt_offset());
1584 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1586 // Get the GOT offset if needed.
1587 // The GOT pointer points to the end of the GOT section.
1588 // We need to subtract the size of the GOT section to get
1589 // the actual offset to use in the relocation.
1590 bool have_got_offset
= false;
1591 unsigned int got_offset
= 0;
1594 case elfcpp::R_386_GOT32
:
1597 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1598 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1599 - target
->got_size());
1603 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1604 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1605 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1606 - target
->got_size());
1608 have_got_offset
= true;
1617 case elfcpp::R_386_NONE
:
1618 case elfcpp::R_386_GNU_VTINHERIT
:
1619 case elfcpp::R_386_GNU_VTENTRY
:
1622 case elfcpp::R_386_32
:
1623 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true))
1624 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1627 case elfcpp::R_386_PC32
:
1629 int ref_flags
= Symbol::NON_PIC_REF
;
1630 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1631 ref_flags
|= Symbol::FUNCTION_CALL
;
1632 if (should_apply_static_reloc(gsym
, ref_flags
, true))
1633 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1637 case elfcpp::R_386_16
:
1638 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1639 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1642 case elfcpp::R_386_PC16
:
1644 int ref_flags
= Symbol::NON_PIC_REF
;
1645 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1646 ref_flags
|= Symbol::FUNCTION_CALL
;
1647 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1648 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1652 case elfcpp::R_386_8
:
1653 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1654 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1657 case elfcpp::R_386_PC8
:
1659 int ref_flags
= Symbol::NON_PIC_REF
;
1660 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1661 ref_flags
|= Symbol::FUNCTION_CALL
;
1662 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1663 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1667 case elfcpp::R_386_PLT32
:
1668 gold_assert(gsym
== NULL
1669 || gsym
->has_plt_offset()
1670 || gsym
->final_value_is_known()
1671 || (gsym
->is_defined()
1672 && !gsym
->is_from_dynobj()
1673 && !gsym
->is_preemptible()));
1674 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1677 case elfcpp::R_386_GOT32
:
1678 gold_assert(have_got_offset
);
1679 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1682 case elfcpp::R_386_GOTOFF
:
1684 elfcpp::Elf_types
<32>::Elf_Addr value
;
1685 value
= (psymval
->value(object
, 0)
1686 - target
->got_plt_section()->address());
1687 Relocate_functions
<32, false>::rel32(view
, value
);
1691 case elfcpp::R_386_GOTPC
:
1693 elfcpp::Elf_types
<32>::Elf_Addr value
;
1694 value
= target
->got_plt_section()->address();
1695 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1699 case elfcpp::R_386_COPY
:
1700 case elfcpp::R_386_GLOB_DAT
:
1701 case elfcpp::R_386_JUMP_SLOT
:
1702 case elfcpp::R_386_RELATIVE
:
1703 // These are outstanding tls relocs, which are unexpected when
1705 case elfcpp::R_386_TLS_TPOFF
:
1706 case elfcpp::R_386_TLS_DTPMOD32
:
1707 case elfcpp::R_386_TLS_DTPOFF32
:
1708 case elfcpp::R_386_TLS_TPOFF32
:
1709 case elfcpp::R_386_TLS_DESC
:
1710 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1711 _("unexpected reloc %u in object file"),
1715 // These are initial tls relocs, which are expected when
1717 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1718 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1719 case elfcpp::R_386_TLS_DESC_CALL
:
1720 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1721 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1722 case elfcpp::R_386_TLS_IE
: // Initial-exec
1723 case elfcpp::R_386_TLS_IE_32
:
1724 case elfcpp::R_386_TLS_GOTIE
:
1725 case elfcpp::R_386_TLS_LE
: // Local-exec
1726 case elfcpp::R_386_TLS_LE_32
:
1727 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1728 view
, address
, view_size
);
1731 case elfcpp::R_386_32PLT
:
1732 case elfcpp::R_386_TLS_GD_32
:
1733 case elfcpp::R_386_TLS_GD_PUSH
:
1734 case elfcpp::R_386_TLS_GD_CALL
:
1735 case elfcpp::R_386_TLS_GD_POP
:
1736 case elfcpp::R_386_TLS_LDM_32
:
1737 case elfcpp::R_386_TLS_LDM_PUSH
:
1738 case elfcpp::R_386_TLS_LDM_CALL
:
1739 case elfcpp::R_386_TLS_LDM_POP
:
1740 case elfcpp::R_386_USED_BY_INTEL_200
:
1742 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1743 _("unsupported reloc %u"),
1751 // Perform a TLS relocation.
1754 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1755 Target_i386
* target
,
1757 const elfcpp::Rel
<32, false>& rel
,
1758 unsigned int r_type
,
1759 const Sized_symbol
<32>* gsym
,
1760 const Symbol_value
<32>* psymval
,
1761 unsigned char* view
,
1762 elfcpp::Elf_types
<32>::Elf_Addr
,
1763 section_size_type view_size
)
1765 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1767 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1769 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1771 const bool is_final
=
1773 ? !parameters
->options().output_is_position_independent()
1774 : gsym
->final_value_is_known());
1775 const tls::Tls_optimization optimized_type
1776 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1779 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1780 if (optimized_type
== tls::TLSOPT_TO_LE
)
1782 gold_assert(tls_segment
!= NULL
);
1783 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1784 rel
, r_type
, value
, view
,
1790 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1791 ? GOT_TYPE_TLS_NOFFSET
1792 : GOT_TYPE_TLS_PAIR
);
1793 unsigned int got_offset
;
1796 gold_assert(gsym
->has_got_offset(got_type
));
1797 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1801 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1802 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1803 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1804 - target
->got_size());
1806 if (optimized_type
== tls::TLSOPT_TO_IE
)
1808 gold_assert(tls_segment
!= NULL
);
1809 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1810 got_offset
, view
, view_size
);
1813 else if (optimized_type
== tls::TLSOPT_NONE
)
1815 // Relocate the field with the offset of the pair of GOT
1817 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1821 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1822 _("unsupported reloc %u"),
1826 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1827 case elfcpp::R_386_TLS_DESC_CALL
:
1828 if (optimized_type
== tls::TLSOPT_TO_LE
)
1830 gold_assert(tls_segment
!= NULL
);
1831 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
1832 rel
, r_type
, value
, view
,
1838 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1839 ? GOT_TYPE_TLS_NOFFSET
1840 : GOT_TYPE_TLS_DESC
);
1841 unsigned int got_offset
;
1844 gold_assert(gsym
->has_got_offset(got_type
));
1845 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1849 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1850 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1851 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1852 - target
->got_size());
1854 if (optimized_type
== tls::TLSOPT_TO_IE
)
1856 gold_assert(tls_segment
!= NULL
);
1857 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1858 got_offset
, view
, view_size
);
1861 else if (optimized_type
== tls::TLSOPT_NONE
)
1863 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
1865 // Relocate the field with the offset of the pair of GOT
1867 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1872 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1873 _("unsupported reloc %u"),
1877 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1878 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
1880 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1881 _("both SUN and GNU model "
1882 "TLS relocations"));
1885 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1886 if (optimized_type
== tls::TLSOPT_TO_LE
)
1888 gold_assert(tls_segment
!= NULL
);
1889 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1890 value
, view
, view_size
);
1893 else if (optimized_type
== tls::TLSOPT_NONE
)
1895 // Relocate the field with the offset of the GOT entry for
1896 // the module index.
1897 unsigned int got_offset
;
1898 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
1899 - target
->got_size());
1900 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1903 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1904 _("unsupported reloc %u"),
1908 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1909 // This reloc can appear in debugging sections, in which case we
1910 // won't see the TLS_LDM reloc. The local_dynamic_type field
1912 if (optimized_type
== tls::TLSOPT_TO_LE
)
1914 gold_assert(tls_segment
!= NULL
);
1915 value
-= tls_segment
->memsz();
1917 Relocate_functions
<32, false>::rel32(view
, value
);
1920 case elfcpp::R_386_TLS_IE
: // Initial-exec
1921 case elfcpp::R_386_TLS_GOTIE
:
1922 case elfcpp::R_386_TLS_IE_32
:
1923 if (optimized_type
== tls::TLSOPT_TO_LE
)
1925 gold_assert(tls_segment
!= NULL
);
1926 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1927 rel
, r_type
, value
, view
,
1931 else if (optimized_type
== tls::TLSOPT_NONE
)
1933 // Relocate the field with the offset of the GOT entry for
1934 // the tp-relative offset of the symbol.
1935 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1936 ? GOT_TYPE_TLS_OFFSET
1937 : GOT_TYPE_TLS_NOFFSET
);
1938 unsigned int got_offset
;
1941 gold_assert(gsym
->has_got_offset(got_type
));
1942 got_offset
= gsym
->got_offset(got_type
);
1946 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1947 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1948 got_offset
= object
->local_got_offset(r_sym
, got_type
);
1950 // For the R_386_TLS_IE relocation, we need to apply the
1951 // absolute address of the GOT entry.
1952 if (r_type
== elfcpp::R_386_TLS_IE
)
1953 got_offset
+= target
->got_plt_section()->address();
1954 // All GOT offsets are relative to the end of the GOT.
1955 got_offset
-= target
->got_size();
1956 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1959 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1960 _("unsupported reloc %u"),
1964 case elfcpp::R_386_TLS_LE
: // Local-exec
1965 // If we're creating a shared library, a dynamic relocation will
1966 // have been created for this location, so do not apply it now.
1967 if (!parameters
->options().shared())
1969 gold_assert(tls_segment
!= NULL
);
1970 value
-= tls_segment
->memsz();
1971 Relocate_functions
<32, false>::rel32(view
, value
);
1975 case elfcpp::R_386_TLS_LE_32
:
1976 // If we're creating a shared library, a dynamic relocation will
1977 // have been created for this location, so do not apply it now.
1978 if (!parameters
->options().shared())
1980 gold_assert(tls_segment
!= NULL
);
1981 value
= tls_segment
->memsz() - value
;
1982 Relocate_functions
<32, false>::rel32(view
, value
);
1988 // Do a relocation in which we convert a TLS General-Dynamic to a
1992 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
1994 Output_segment
* tls_segment
,
1995 const elfcpp::Rel
<32, false>& rel
,
1997 elfcpp::Elf_types
<32>::Elf_Addr value
,
1998 unsigned char* view
,
1999 section_size_type view_size
)
2001 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2002 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2003 // leal foo(%reg),%eax; call ___tls_get_addr
2004 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2006 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2007 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2009 unsigned char op1
= view
[-1];
2010 unsigned char op2
= view
[-2];
2012 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2013 op2
== 0x8d || op2
== 0x04);
2014 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2020 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2021 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2022 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2023 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2024 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2028 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2029 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2030 if (rel
.get_r_offset() + 9 < view_size
2033 // There is a trailing nop. Use the size byte subl.
2034 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2039 // Use the five byte subl.
2040 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2044 value
= tls_segment
->memsz() - value
;
2045 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2047 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2049 this->skip_call_tls_get_addr_
= true;
2052 // Do a relocation in which we convert a TLS General-Dynamic to an
2056 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2059 const elfcpp::Rel
<32, false>& rel
,
2061 elfcpp::Elf_types
<32>::Elf_Addr value
,
2062 unsigned char* view
,
2063 section_size_type view_size
)
2065 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2066 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2068 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2069 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2071 unsigned char op1
= view
[-1];
2072 unsigned char op2
= view
[-2];
2074 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2075 op2
== 0x8d || op2
== 0x04);
2076 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2080 // FIXME: For now, support only the first (SIB) form.
2081 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2085 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2086 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2087 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2088 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2089 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2093 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2094 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2095 if (rel
.get_r_offset() + 9 < view_size
2098 // FIXME: This is not the right instruction sequence.
2099 // There is a trailing nop. Use the size byte subl.
2100 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2105 // FIXME: This is not the right instruction sequence.
2106 // Use the five byte subl.
2107 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2111 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2113 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2115 this->skip_call_tls_get_addr_
= true;
2118 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2119 // General-Dynamic to a Local-Exec.
2122 Target_i386::Relocate::tls_desc_gd_to_le(
2123 const Relocate_info
<32, false>* relinfo
,
2125 Output_segment
* tls_segment
,
2126 const elfcpp::Rel
<32, false>& rel
,
2127 unsigned int r_type
,
2128 elfcpp::Elf_types
<32>::Elf_Addr value
,
2129 unsigned char* view
,
2130 section_size_type view_size
)
2132 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2134 // leal foo@TLSDESC(%ebx), %eax
2135 // ==> leal foo@NTPOFF, %eax
2136 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2137 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2138 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2139 view
[-2] == 0x8d && view
[-1] == 0x83);
2141 value
-= tls_segment
->memsz();
2142 Relocate_functions
<32, false>::rel32(view
, value
);
2146 // call *foo@TLSCALL(%eax)
2148 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2149 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2150 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2151 view
[0] == 0xff && view
[1] == 0x10);
2157 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2158 // General-Dynamic to an Initial-Exec.
2161 Target_i386::Relocate::tls_desc_gd_to_ie(
2162 const Relocate_info
<32, false>* relinfo
,
2165 const elfcpp::Rel
<32, false>& rel
,
2166 unsigned int r_type
,
2167 elfcpp::Elf_types
<32>::Elf_Addr value
,
2168 unsigned char* view
,
2169 section_size_type view_size
)
2171 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2173 // leal foo@TLSDESC(%ebx), %eax
2174 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2175 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2176 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2177 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2178 view
[-2] == 0x8d && view
[-1] == 0x83);
2180 Relocate_functions
<32, false>::rel32(view
, value
);
2184 // call *foo@TLSCALL(%eax)
2186 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2187 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2188 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2189 view
[0] == 0xff && view
[1] == 0x10);
2195 // Do a relocation in which we convert a TLS Local-Dynamic to a
2199 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2202 const elfcpp::Rel
<32, false>& rel
,
2204 elfcpp::Elf_types
<32>::Elf_Addr
,
2205 unsigned char* view
,
2206 section_size_type view_size
)
2208 // leal foo(%reg), %eax; call ___tls_get_addr
2209 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2211 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2212 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2214 // FIXME: Does this test really always pass?
2215 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2216 view
[-2] == 0x8d && view
[-1] == 0x83);
2218 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2220 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2222 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2224 this->skip_call_tls_get_addr_
= true;
2227 // Do a relocation in which we convert a TLS Initial-Exec to a
2231 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2233 Output_segment
* tls_segment
,
2234 const elfcpp::Rel
<32, false>& rel
,
2235 unsigned int r_type
,
2236 elfcpp::Elf_types
<32>::Elf_Addr value
,
2237 unsigned char* view
,
2238 section_size_type view_size
)
2240 // We have to actually change the instructions, which means that we
2241 // need to examine the opcodes to figure out which instruction we
2243 if (r_type
== elfcpp::R_386_TLS_IE
)
2245 // movl %gs:XX,%eax ==> movl $YY,%eax
2246 // movl %gs:XX,%reg ==> movl $YY,%reg
2247 // addl %gs:XX,%reg ==> addl $YY,%reg
2248 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2249 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2251 unsigned char op1
= view
[-1];
2254 // movl XX,%eax ==> movl $YY,%eax
2259 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2261 unsigned char op2
= view
[-2];
2264 // movl XX,%reg ==> movl $YY,%reg
2265 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2266 (op1
& 0xc7) == 0x05);
2268 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2270 else if (op2
== 0x03)
2272 // addl XX,%reg ==> addl $YY,%reg
2273 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2274 (op1
& 0xc7) == 0x05);
2276 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2279 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2284 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2285 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2286 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2287 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2288 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2290 unsigned char op1
= view
[-1];
2291 unsigned char op2
= view
[-2];
2292 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2293 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2296 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2298 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2300 else if (op2
== 0x2b)
2302 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2304 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2306 else if (op2
== 0x03)
2308 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2310 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2313 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2316 value
= tls_segment
->memsz() - value
;
2317 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2320 Relocate_functions
<32, false>::rel32(view
, value
);
2323 // Relocate section data.
2326 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2327 unsigned int sh_type
,
2328 const unsigned char* prelocs
,
2330 Output_section
* output_section
,
2331 bool needs_special_offset_handling
,
2332 unsigned char* view
,
2333 elfcpp::Elf_types
<32>::Elf_Addr address
,
2334 section_size_type view_size
)
2336 gold_assert(sh_type
== elfcpp::SHT_REL
);
2338 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2339 Target_i386::Relocate
>(
2345 needs_special_offset_handling
,
2351 // Return the size of a relocation while scanning during a relocatable
2355 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2356 unsigned int r_type
,
2361 case elfcpp::R_386_NONE
:
2362 case elfcpp::R_386_GNU_VTINHERIT
:
2363 case elfcpp::R_386_GNU_VTENTRY
:
2364 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2365 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2366 case elfcpp::R_386_TLS_DESC_CALL
:
2367 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2368 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2369 case elfcpp::R_386_TLS_IE
: // Initial-exec
2370 case elfcpp::R_386_TLS_IE_32
:
2371 case elfcpp::R_386_TLS_GOTIE
:
2372 case elfcpp::R_386_TLS_LE
: // Local-exec
2373 case elfcpp::R_386_TLS_LE_32
:
2376 case elfcpp::R_386_32
:
2377 case elfcpp::R_386_PC32
:
2378 case elfcpp::R_386_GOT32
:
2379 case elfcpp::R_386_PLT32
:
2380 case elfcpp::R_386_GOTOFF
:
2381 case elfcpp::R_386_GOTPC
:
2384 case elfcpp::R_386_16
:
2385 case elfcpp::R_386_PC16
:
2388 case elfcpp::R_386_8
:
2389 case elfcpp::R_386_PC8
:
2392 // These are relocations which should only be seen by the
2393 // dynamic linker, and should never be seen here.
2394 case elfcpp::R_386_COPY
:
2395 case elfcpp::R_386_GLOB_DAT
:
2396 case elfcpp::R_386_JUMP_SLOT
:
2397 case elfcpp::R_386_RELATIVE
:
2398 case elfcpp::R_386_TLS_TPOFF
:
2399 case elfcpp::R_386_TLS_DTPMOD32
:
2400 case elfcpp::R_386_TLS_DTPOFF32
:
2401 case elfcpp::R_386_TLS_TPOFF32
:
2402 case elfcpp::R_386_TLS_DESC
:
2403 object
->error(_("unexpected reloc %u in object file"), r_type
);
2406 case elfcpp::R_386_32PLT
:
2407 case elfcpp::R_386_TLS_GD_32
:
2408 case elfcpp::R_386_TLS_GD_PUSH
:
2409 case elfcpp::R_386_TLS_GD_CALL
:
2410 case elfcpp::R_386_TLS_GD_POP
:
2411 case elfcpp::R_386_TLS_LDM_32
:
2412 case elfcpp::R_386_TLS_LDM_PUSH
:
2413 case elfcpp::R_386_TLS_LDM_CALL
:
2414 case elfcpp::R_386_TLS_LDM_POP
:
2415 case elfcpp::R_386_USED_BY_INTEL_200
:
2417 object
->error(_("unsupported reloc %u in object file"), r_type
);
2422 // Scan the relocs during a relocatable link.
2425 Target_i386::scan_relocatable_relocs(const General_options
& options
,
2426 Symbol_table
* symtab
,
2428 Sized_relobj
<32, false>* object
,
2429 unsigned int data_shndx
,
2430 unsigned int sh_type
,
2431 const unsigned char* prelocs
,
2433 Output_section
* output_section
,
2434 bool needs_special_offset_handling
,
2435 size_t local_symbol_count
,
2436 const unsigned char* plocal_symbols
,
2437 Relocatable_relocs
* rr
)
2439 gold_assert(sh_type
== elfcpp::SHT_REL
);
2441 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2442 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2444 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2445 Scan_relocatable_relocs
>(
2454 needs_special_offset_handling
,
2460 // Relocate a section during a relocatable link.
2463 Target_i386::relocate_for_relocatable(
2464 const Relocate_info
<32, false>* relinfo
,
2465 unsigned int sh_type
,
2466 const unsigned char* prelocs
,
2468 Output_section
* output_section
,
2469 off_t offset_in_output_section
,
2470 const Relocatable_relocs
* rr
,
2471 unsigned char* view
,
2472 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2473 section_size_type view_size
,
2474 unsigned char* reloc_view
,
2475 section_size_type reloc_view_size
)
2477 gold_assert(sh_type
== elfcpp::SHT_REL
);
2479 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2484 offset_in_output_section
,
2493 // Return the value to use for a dynamic which requires special
2494 // treatment. This is how we support equality comparisons of function
2495 // pointers across shared library boundaries, as described in the
2496 // processor specific ABI supplement.
2499 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2501 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2502 return this->plt_section()->address() + gsym
->plt_offset();
2505 // Return a string used to fill a code section with nops to take up
2506 // the specified length.
2509 Target_i386::do_code_fill(section_size_type length
) const
2513 // Build a jmp instruction to skip over the bytes.
2514 unsigned char jmp
[5];
2516 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2517 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2518 + std::string(length
- 5, '\0'));
2521 // Nop sequences of various lengths.
2522 const char nop1
[1] = { 0x90 }; // nop
2523 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2524 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2525 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2526 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2527 0x00 }; // leal 0(%esi,1),%esi
2528 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2530 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2532 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2533 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2534 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2535 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2537 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2538 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2540 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2541 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2543 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2544 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2545 0x00, 0x00, 0x00, 0x00 };
2546 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2547 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2548 0x27, 0x00, 0x00, 0x00,
2550 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2551 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2552 0xbc, 0x27, 0x00, 0x00,
2554 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2555 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2556 0x90, 0x90, 0x90, 0x90,
2559 const char* nops
[16] = {
2561 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2562 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2565 return std::string(nops
[length
], length
);
2568 // The selector for i386 object files.
2570 class Target_selector_i386
: public Target_selector
2573 Target_selector_i386()
2574 : Target_selector(elfcpp::EM_386
, 32, false, "elf32-i386")
2578 do_instantiate_target()
2579 { return new Target_i386(); }
2582 Target_selector_i386 target_selector_i386
;
2584 } // End anonymous namespace.