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"
36 #include "target-reloc.h"
37 #include "target-select.h"
45 class Output_data_plt_i386
;
47 // The i386 target class.
48 // TLS info comes from
49 // http://people.redhat.com/drepper/tls.pdf
50 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
52 class Target_i386
: public Sized_target
<32, false>
55 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
58 : Sized_target
<32, false>(&i386_info
),
59 got_(NULL
), plt_(NULL
), got_plt_(NULL
), rel_dyn_(NULL
),
60 copy_relocs_(NULL
), dynbss_(NULL
), got_mod_index_offset_(-1U)
63 // Scan the relocations to look for symbol adjustments.
65 scan_relocs(const General_options
& options
,
68 Sized_relobj
<32, false>* object
,
69 unsigned int data_shndx
,
71 const unsigned char* prelocs
,
73 Output_section
* output_section
,
74 bool needs_special_offset_handling
,
75 size_t local_symbol_count
,
76 const unsigned char* plocal_symbols
);
78 // Finalize the sections.
80 do_finalize_sections(Layout
*);
82 // Return the value to use for a dynamic which requires special
85 do_dynsym_value(const Symbol
*) const;
87 // Relocate a section.
89 relocate_section(const Relocate_info
<32, false>*,
91 const unsigned char* prelocs
,
93 Output_section
* output_section
,
94 bool needs_special_offset_handling
,
96 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
97 section_size_type view_size
);
99 // Scan the relocs during a relocatable link.
101 scan_relocatable_relocs(const General_options
& options
,
102 Symbol_table
* symtab
,
104 Sized_relobj
<32, false>* object
,
105 unsigned int data_shndx
,
106 unsigned int sh_type
,
107 const unsigned char* prelocs
,
109 Output_section
* output_section
,
110 bool needs_special_offset_handling
,
111 size_t local_symbol_count
,
112 const unsigned char* plocal_symbols
,
113 Relocatable_relocs
*);
115 // Relocate a section during a relocatable link.
117 relocate_for_relocatable(const Relocate_info
<32, false>*,
118 unsigned int sh_type
,
119 const unsigned char* prelocs
,
121 Output_section
* output_section
,
122 off_t offset_in_output_section
,
123 const Relocatable_relocs
*,
125 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
126 section_size_type view_size
,
127 unsigned char* reloc_view
,
128 section_size_type reloc_view_size
);
130 // Return a string used to fill a code section with nops.
132 do_code_fill(section_size_type length
) const;
134 // Return whether SYM is defined by the ABI.
136 do_is_defined_by_abi(Symbol
* sym
) const
137 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
139 // Return the size of the GOT section.
143 gold_assert(this->got_
!= NULL
);
144 return this->got_
->data_size();
148 // The class which scans relocations.
152 local(const General_options
& options
, Symbol_table
* symtab
,
153 Layout
* layout
, Target_i386
* target
,
154 Sized_relobj
<32, false>* object
,
155 unsigned int data_shndx
,
156 Output_section
* output_section
,
157 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
158 const elfcpp::Sym
<32, false>& lsym
);
161 global(const General_options
& options
, Symbol_table
* symtab
,
162 Layout
* layout
, Target_i386
* target
,
163 Sized_relobj
<32, false>* object
,
164 unsigned int data_shndx
,
165 Output_section
* output_section
,
166 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
170 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
173 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
177 // The class which implements relocation.
182 : skip_call_tls_get_addr_(false),
183 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
188 if (this->skip_call_tls_get_addr_
)
190 // FIXME: This needs to specify the location somehow.
191 gold_error(_("missing expected TLS relocation"));
195 // Return whether the static relocation needs to be applied.
197 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
201 // Do a relocation. Return false if the caller should not issue
202 // any warnings about this relocation.
204 relocate(const Relocate_info
<32, false>*, Target_i386
*, size_t relnum
,
205 const elfcpp::Rel
<32, false>&,
206 unsigned int r_type
, const Sized_symbol
<32>*,
207 const Symbol_value
<32>*,
208 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
212 // Do a TLS relocation.
214 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
215 size_t relnum
, const elfcpp::Rel
<32, false>&,
216 unsigned int r_type
, const Sized_symbol
<32>*,
217 const Symbol_value
<32>*,
218 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
221 // Do a TLS General-Dynamic to Initial-Exec transition.
223 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
224 Output_segment
* tls_segment
,
225 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
226 elfcpp::Elf_types
<32>::Elf_Addr value
,
228 section_size_type view_size
);
230 // Do a TLS General-Dynamic to Local-Exec transition.
232 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
233 Output_segment
* tls_segment
,
234 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
235 elfcpp::Elf_types
<32>::Elf_Addr value
,
237 section_size_type view_size
);
239 // Do a TLS Local-Dynamic to Local-Exec transition.
241 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
242 Output_segment
* tls_segment
,
243 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
244 elfcpp::Elf_types
<32>::Elf_Addr value
,
246 section_size_type view_size
);
248 // Do a TLS Initial-Exec to Local-Exec transition.
250 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
251 Output_segment
* tls_segment
,
252 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
253 elfcpp::Elf_types
<32>::Elf_Addr value
,
255 section_size_type view_size
);
257 // We need to keep track of which type of local dynamic relocation
258 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
259 enum Local_dynamic_type
266 // This is set if we should skip the next reloc, which should be a
267 // PLT32 reloc against ___tls_get_addr.
268 bool skip_call_tls_get_addr_
;
269 // The type of local dynamic relocation we have seen in the section
270 // being relocated, if any.
271 Local_dynamic_type local_dynamic_type_
;
274 // A class which returns the size required for a relocation type,
275 // used while scanning relocs during a relocatable link.
276 class Relocatable_size_for_reloc
280 get_size_for_reloc(unsigned int, Relobj
*);
283 // Adjust TLS relocation type based on the options and whether this
284 // is a local symbol.
285 static tls::Tls_optimization
286 optimize_tls_reloc(bool is_final
, int r_type
);
288 // Get the GOT section, creating it if necessary.
289 Output_data_got
<32, false>*
290 got_section(Symbol_table
*, Layout
*);
292 // Get the GOT PLT section.
294 got_plt_section() const
296 gold_assert(this->got_plt_
!= NULL
);
297 return this->got_plt_
;
300 // Create a PLT entry for a global symbol.
302 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
304 // Create a GOT entry for the TLS module index.
306 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
307 Sized_relobj
<32, false>* object
);
309 // Get the PLT section.
310 const Output_data_plt_i386
*
313 gold_assert(this->plt_
!= NULL
);
317 // Get the dynamic reloc section, creating it if necessary.
319 rel_dyn_section(Layout
*);
321 // Return true if the symbol may need a COPY relocation.
322 // References from an executable object to non-function symbols
323 // defined in a dynamic object may need a COPY relocation.
325 may_need_copy_reloc(Symbol
* gsym
)
327 return (!parameters
->options().shared()
328 && gsym
->is_from_dynobj()
329 && gsym
->type() != elfcpp::STT_FUNC
);
332 // Copy a relocation against a global symbol.
334 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
335 Sized_relobj
<32, false>*, unsigned int,
336 Output_section
*, Symbol
*, const elfcpp::Rel
<32, false>&);
338 // Information about this specific target which we pass to the
339 // general Target structure.
340 static const Target::Target_info i386_info
;
342 // The types of GOT entries needed for this platform.
345 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
346 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
347 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
348 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
352 Output_data_got
<32, false>* got_
;
354 Output_data_plt_i386
* plt_
;
355 // The GOT PLT section.
356 Output_data_space
* got_plt_
;
357 // The dynamic reloc section.
358 Reloc_section
* rel_dyn_
;
359 // Relocs saved to avoid a COPY reloc.
360 Copy_relocs
<32, false>* copy_relocs_
;
361 // Space for variables copied with a COPY reloc.
362 Output_data_space
* dynbss_
;
363 // Offset of the GOT entry for the TLS module index;
364 unsigned int got_mod_index_offset_
;
367 const Target::Target_info
Target_i386::i386_info
=
370 false, // is_big_endian
371 elfcpp::EM_386
, // machine_code
372 false, // has_make_symbol
373 false, // has_resolve
374 true, // has_code_fill
375 true, // is_default_stack_executable
377 "/usr/lib/libc.so.1", // dynamic_linker
378 0x08048000, // default_text_segment_address
379 0x1000, // abi_pagesize (overridable by -z max-page-size)
380 0x1000 // common_pagesize (overridable by -z common-page-size)
383 // Get the GOT section, creating it if necessary.
385 Output_data_got
<32, false>*
386 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
388 if (this->got_
== NULL
)
390 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
392 this->got_
= new Output_data_got
<32, false>();
394 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
395 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
398 // The old GNU linker creates a .got.plt section. We just
399 // create another set of data in the .got section. Note that we
400 // always create a PLT if we create a GOT, although the PLT
402 this->got_plt_
= new Output_data_space(4);
403 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
404 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
407 // The first three entries are reserved.
408 this->got_plt_
->set_current_data_size(3 * 4);
410 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
411 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
413 0, 0, elfcpp::STT_OBJECT
,
415 elfcpp::STV_HIDDEN
, 0,
422 // Get the dynamic reloc section, creating it if necessary.
424 Target_i386::Reloc_section
*
425 Target_i386::rel_dyn_section(Layout
* layout
)
427 if (this->rel_dyn_
== NULL
)
429 gold_assert(layout
!= NULL
);
430 this->rel_dyn_
= new Reloc_section();
431 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
432 elfcpp::SHF_ALLOC
, this->rel_dyn_
);
434 return this->rel_dyn_
;
437 // A class to handle the PLT data.
439 class Output_data_plt_i386
: public Output_section_data
442 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
444 Output_data_plt_i386(Layout
*, Output_data_space
*);
446 // Add an entry to the PLT.
448 add_entry(Symbol
* gsym
);
450 // Return the .rel.plt section data.
453 { return this->rel_
; }
457 do_adjust_output_section(Output_section
* os
);
460 // The size of an entry in the PLT.
461 static const int plt_entry_size
= 16;
463 // The first entry in the PLT for an executable.
464 static unsigned char exec_first_plt_entry
[plt_entry_size
];
466 // The first entry in the PLT for a shared object.
467 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
469 // Other entries in the PLT for an executable.
470 static unsigned char exec_plt_entry
[plt_entry_size
];
472 // Other entries in the PLT for a shared object.
473 static unsigned char dyn_plt_entry
[plt_entry_size
];
475 // Set the final size.
477 set_final_data_size()
478 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
480 // Write out the PLT data.
482 do_write(Output_file
*);
484 // The reloc section.
486 // The .got.plt section.
487 Output_data_space
* got_plt_
;
488 // The number of PLT entries.
492 // Create the PLT section. The ordinary .got section is an argument,
493 // since we need to refer to the start. We also create our own .got
494 // section just for PLT entries.
496 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
497 Output_data_space
* got_plt
)
498 : Output_section_data(4), got_plt_(got_plt
), count_(0)
500 this->rel_
= new Reloc_section();
501 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
502 elfcpp::SHF_ALLOC
, this->rel_
);
506 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
508 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
509 // linker, and so do we.
513 // Add an entry to the PLT.
516 Output_data_plt_i386::add_entry(Symbol
* gsym
)
518 gold_assert(!gsym
->has_plt_offset());
520 // Note that when setting the PLT offset we skip the initial
521 // reserved PLT entry.
522 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
526 section_offset_type got_offset
= this->got_plt_
->current_data_size();
528 // Every PLT entry needs a GOT entry which points back to the PLT
529 // entry (this will be changed by the dynamic linker, normally
530 // lazily when the function is called).
531 this->got_plt_
->set_current_data_size(got_offset
+ 4);
533 // Every PLT entry needs a reloc.
534 gsym
->set_needs_dynsym_entry();
535 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
538 // Note that we don't need to save the symbol. The contents of the
539 // PLT are independent of which symbols are used. The symbols only
540 // appear in the relocations.
543 // The first entry in the PLT for an executable.
545 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
547 0xff, 0x35, // pushl contents of memory address
548 0, 0, 0, 0, // replaced with address of .got + 4
549 0xff, 0x25, // jmp indirect
550 0, 0, 0, 0, // replaced with address of .got + 8
554 // The first entry in the PLT for a shared object.
556 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
558 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
559 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
563 // Subsequent entries in the PLT for an executable.
565 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
567 0xff, 0x25, // jmp indirect
568 0, 0, 0, 0, // replaced with address of symbol in .got
569 0x68, // pushl immediate
570 0, 0, 0, 0, // replaced with offset into relocation table
571 0xe9, // jmp relative
572 0, 0, 0, 0 // replaced with offset to start of .plt
575 // Subsequent entries in the PLT for a shared object.
577 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
579 0xff, 0xa3, // jmp *offset(%ebx)
580 0, 0, 0, 0, // replaced with offset of symbol in .got
581 0x68, // pushl immediate
582 0, 0, 0, 0, // replaced with offset into relocation table
583 0xe9, // jmp relative
584 0, 0, 0, 0 // replaced with offset to start of .plt
587 // Write out the PLT. This uses the hand-coded instructions above,
588 // and adjusts them as needed. This is all specified by the i386 ELF
589 // Processor Supplement.
592 Output_data_plt_i386::do_write(Output_file
* of
)
594 const off_t offset
= this->offset();
595 const section_size_type oview_size
=
596 convert_to_section_size_type(this->data_size());
597 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
599 const off_t got_file_offset
= this->got_plt_
->offset();
600 const section_size_type got_size
=
601 convert_to_section_size_type(this->got_plt_
->data_size());
602 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
605 unsigned char* pov
= oview
;
607 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
608 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
610 if (parameters
->options().shared())
611 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
614 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
615 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
616 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
618 pov
+= plt_entry_size
;
620 unsigned char* got_pov
= got_view
;
622 memset(got_pov
, 0, 12);
625 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
627 unsigned int plt_offset
= plt_entry_size
;
628 unsigned int plt_rel_offset
= 0;
629 unsigned int got_offset
= 12;
630 const unsigned int count
= this->count_
;
631 for (unsigned int i
= 0;
634 pov
+= plt_entry_size
,
636 plt_offset
+= plt_entry_size
,
637 plt_rel_offset
+= rel_size
,
640 // Set and adjust the PLT entry itself.
642 if (parameters
->options().shared())
644 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
645 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
649 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
650 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
655 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
656 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
657 - (plt_offset
+ plt_entry_size
));
659 // Set the entry in the GOT.
660 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
663 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
664 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
666 of
->write_output_view(offset
, oview_size
, oview
);
667 of
->write_output_view(got_file_offset
, got_size
, got_view
);
670 // Create a PLT entry for a global symbol.
673 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
675 if (gsym
->has_plt_offset())
678 if (this->plt_
== NULL
)
680 // Create the GOT sections first.
681 this->got_section(symtab
, layout
);
683 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
684 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
686 | elfcpp::SHF_EXECINSTR
),
690 this->plt_
->add_entry(gsym
);
693 // Create a GOT entry for the TLS module index.
696 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
697 Sized_relobj
<32, false>* object
)
699 if (this->got_mod_index_offset_
== -1U)
701 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
702 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
703 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
704 unsigned int got_offset
= got
->add_constant(0);
705 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
707 got
->add_constant(0);
708 this->got_mod_index_offset_
= got_offset
;
710 return this->got_mod_index_offset_
;
713 // Handle a relocation against a non-function symbol defined in a
714 // dynamic object. The traditional way to handle this is to generate
715 // a COPY relocation to copy the variable at runtime from the shared
716 // object into the executable's data segment. However, this is
717 // undesirable in general, as if the size of the object changes in the
718 // dynamic object, the executable will no longer work correctly. If
719 // this relocation is in a writable section, then we can create a
720 // dynamic reloc and the dynamic linker will resolve it to the correct
721 // address at runtime. However, we do not want do that if the
722 // relocation is in a read-only section, as it would prevent the
723 // readonly segment from being shared. And if we have to eventually
724 // generate a COPY reloc, then any dynamic relocations will be
725 // useless. So this means that if this is a writable section, we need
726 // to save the relocation until we see whether we have to create a
727 // COPY relocation for this symbol for any other relocation.
730 Target_i386::copy_reloc(const General_options
* options
,
731 Symbol_table
* symtab
,
733 Sized_relobj
<32, false>* object
,
734 unsigned int data_shndx
,
735 Output_section
* output_section
,
737 const elfcpp::Rel
<32, false>& rel
)
739 Sized_symbol
<32>* ssym
= symtab
->get_sized_symbol
<32>(gsym
);
741 if (!Copy_relocs
<32, false>::need_copy_reloc(options
, object
,
744 // So far we do not need a COPY reloc. Save this relocation.
745 // If it turns out that we never need a COPY reloc for this
746 // symbol, then we will emit the relocation.
747 if (this->copy_relocs_
== NULL
)
748 this->copy_relocs_
= new Copy_relocs
<32, false>();
749 this->copy_relocs_
->save(ssym
, object
, data_shndx
, output_section
, rel
);
753 // Allocate space for this symbol in the .bss section.
755 elfcpp::Elf_types
<32>::Elf_WXword symsize
= ssym
->symsize();
757 // There is no defined way to determine the required alignment
758 // of the symbol. We pick the alignment based on the size. We
759 // set an arbitrary maximum of 256.
761 for (align
= 1; align
< 512; align
<<= 1)
762 if ((symsize
& align
) != 0)
765 if (this->dynbss_
== NULL
)
767 this->dynbss_
= new Output_data_space(align
);
768 layout
->add_output_section_data(".bss",
771 | elfcpp::SHF_WRITE
),
775 Output_data_space
* dynbss
= this->dynbss_
;
777 if (align
> dynbss
->addralign())
778 dynbss
->set_space_alignment(align
);
780 section_size_type dynbss_size
=
781 convert_to_section_size_type(dynbss
->current_data_size());
782 dynbss_size
= align_address(dynbss_size
, align
);
783 section_size_type offset
= dynbss_size
;
784 dynbss
->set_current_data_size(dynbss_size
+ symsize
);
786 symtab
->define_with_copy_reloc(ssym
, dynbss
, offset
);
788 // Add the COPY reloc.
789 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
790 rel_dyn
->add_global(ssym
, elfcpp::R_386_COPY
, dynbss
, offset
);
794 // Optimize the TLS relocation type based on what we know about the
795 // symbol. IS_FINAL is true if the final address of this symbol is
796 // known at link time.
798 tls::Tls_optimization
799 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
801 // If we are generating a shared library, then we can't do anything
803 if (parameters
->options().shared())
804 return tls::TLSOPT_NONE
;
808 case elfcpp::R_386_TLS_GD
:
809 case elfcpp::R_386_TLS_GOTDESC
:
810 case elfcpp::R_386_TLS_DESC_CALL
:
811 // These are General-Dynamic which permits fully general TLS
812 // access. Since we know that we are generating an executable,
813 // we can convert this to Initial-Exec. If we also know that
814 // this is a local symbol, we can further switch to Local-Exec.
816 return tls::TLSOPT_TO_LE
;
817 return tls::TLSOPT_TO_IE
;
819 case elfcpp::R_386_TLS_LDM
:
820 // This is Local-Dynamic, which refers to a local symbol in the
821 // dynamic TLS block. Since we know that we generating an
822 // executable, we can switch to Local-Exec.
823 return tls::TLSOPT_TO_LE
;
825 case elfcpp::R_386_TLS_LDO_32
:
826 // Another type of Local-Dynamic relocation.
827 return tls::TLSOPT_TO_LE
;
829 case elfcpp::R_386_TLS_IE
:
830 case elfcpp::R_386_TLS_GOTIE
:
831 case elfcpp::R_386_TLS_IE_32
:
832 // These are Initial-Exec relocs which get the thread offset
833 // from the GOT. If we know that we are linking against the
834 // local symbol, we can switch to Local-Exec, which links the
835 // thread offset into the instruction.
837 return tls::TLSOPT_TO_LE
;
838 return tls::TLSOPT_NONE
;
840 case elfcpp::R_386_TLS_LE
:
841 case elfcpp::R_386_TLS_LE_32
:
842 // When we already have Local-Exec, there is nothing further we
844 return tls::TLSOPT_NONE
;
851 // Report an unsupported relocation against a local symbol.
854 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
857 gold_error(_("%s: unsupported reloc %u against local symbol"),
858 object
->name().c_str(), r_type
);
861 // Scan a relocation for a local symbol.
864 Target_i386::Scan::local(const General_options
&,
865 Symbol_table
* symtab
,
868 Sized_relobj
<32, false>* object
,
869 unsigned int data_shndx
,
870 Output_section
* output_section
,
871 const elfcpp::Rel
<32, false>& reloc
,
873 const elfcpp::Sym
<32, false>& lsym
)
877 case elfcpp::R_386_NONE
:
878 case elfcpp::R_386_GNU_VTINHERIT
:
879 case elfcpp::R_386_GNU_VTENTRY
:
882 case elfcpp::R_386_32
:
883 // If building a shared library (or a position-independent
884 // executable), we need to create a dynamic relocation for
885 // this location. The relocation applied at link time will
886 // apply the link-time value, so we flag the location with
887 // an R_386_RELATIVE relocation so the dynamic loader can
888 // relocate it easily.
889 if (parameters
->options().output_is_position_independent())
891 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
892 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
893 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
894 output_section
, data_shndx
,
895 reloc
.get_r_offset());
899 case elfcpp::R_386_16
:
900 case elfcpp::R_386_8
:
901 // If building a shared library (or a position-independent
902 // executable), we need to create a dynamic relocation for
903 // this location. Because the addend needs to remain in the
904 // data section, we need to be careful not to apply this
905 // relocation statically.
906 if (parameters
->options().output_is_position_independent())
908 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
909 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
911 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
912 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
913 data_shndx
, reloc
.get_r_offset());
917 gold_assert(lsym
.get_st_value() == 0);
918 rel_dyn
->add_local_section(object
, lsym
.get_st_shndx(),
919 r_type
, output_section
,
920 data_shndx
, reloc
.get_r_offset());
925 case elfcpp::R_386_PC32
:
926 case elfcpp::R_386_PC16
:
927 case elfcpp::R_386_PC8
:
930 case elfcpp::R_386_PLT32
:
931 // Since we know this is a local symbol, we can handle this as a
935 case elfcpp::R_386_GOTOFF
:
936 case elfcpp::R_386_GOTPC
:
937 // We need a GOT section.
938 target
->got_section(symtab
, layout
);
941 case elfcpp::R_386_GOT32
:
943 // The symbol requires a GOT entry.
944 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
945 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
946 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
948 // If we are generating a shared object, we need to add a
949 // dynamic RELATIVE relocation for this symbol's GOT entry.
950 if (parameters
->options().output_is_position_independent())
952 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
953 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
954 rel_dyn
->add_local_relative(
955 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
956 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
962 // These are relocations which should only be seen by the
963 // dynamic linker, and should never be seen here.
964 case elfcpp::R_386_COPY
:
965 case elfcpp::R_386_GLOB_DAT
:
966 case elfcpp::R_386_JUMP_SLOT
:
967 case elfcpp::R_386_RELATIVE
:
968 case elfcpp::R_386_TLS_TPOFF
:
969 case elfcpp::R_386_TLS_DTPMOD32
:
970 case elfcpp::R_386_TLS_DTPOFF32
:
971 case elfcpp::R_386_TLS_TPOFF32
:
972 case elfcpp::R_386_TLS_DESC
:
973 gold_error(_("%s: unexpected reloc %u in object file"),
974 object
->name().c_str(), r_type
);
977 // These are initial TLS relocs, which are expected when
979 case elfcpp::R_386_TLS_GD
: // Global-dynamic
980 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
981 case elfcpp::R_386_TLS_DESC_CALL
:
982 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
983 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
984 case elfcpp::R_386_TLS_IE
: // Initial-exec
985 case elfcpp::R_386_TLS_IE_32
:
986 case elfcpp::R_386_TLS_GOTIE
:
987 case elfcpp::R_386_TLS_LE
: // Local-exec
988 case elfcpp::R_386_TLS_LE_32
:
990 bool output_is_shared
= parameters
->options().shared();
991 const tls::Tls_optimization optimized_type
992 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
995 case elfcpp::R_386_TLS_GD
: // Global-dynamic
996 if (optimized_type
== tls::TLSOPT_NONE
)
998 // Create a pair of GOT entries for the module index and
999 // dtv-relative offset.
1000 Output_data_got
<32, false>* got
1001 = target
->got_section(symtab
, layout
);
1002 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1003 got
->add_local_pair_with_rel(object
, r_sym
,
1004 lsym
.get_st_shndx(),
1006 target
->rel_dyn_section(layout
),
1007 elfcpp::R_386_TLS_DTPMOD32
, 0);
1009 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1010 unsupported_reloc_local(object
, r_type
);
1013 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1014 case elfcpp::R_386_TLS_DESC_CALL
:
1015 // FIXME: If not relaxing to LE, we need to generate
1016 // a GOT entry with an R_386_TLS_DESC reloc.
1017 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1018 unsupported_reloc_local(object
, r_type
);
1021 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1022 if (optimized_type
== tls::TLSOPT_NONE
)
1024 // Create a GOT entry for the module index.
1025 target
->got_mod_index_entry(symtab
, layout
, object
);
1027 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1028 unsupported_reloc_local(object
, r_type
);
1031 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1034 case elfcpp::R_386_TLS_IE
: // Initial-exec
1035 case elfcpp::R_386_TLS_IE_32
:
1036 case elfcpp::R_386_TLS_GOTIE
:
1037 layout
->set_has_static_tls();
1038 if (optimized_type
== tls::TLSOPT_NONE
)
1040 // For the R_386_TLS_IE relocation, we need to create a
1041 // dynamic relocation when building a shared library.
1042 if (r_type
== elfcpp::R_386_TLS_IE
1043 && parameters
->options().shared())
1045 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1047 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1048 rel_dyn
->add_local_relative(object
, r_sym
,
1049 elfcpp::R_386_RELATIVE
,
1050 output_section
, data_shndx
,
1051 reloc
.get_r_offset());
1053 // Create a GOT entry for the tp-relative offset.
1054 Output_data_got
<32, false>* got
1055 = target
->got_section(symtab
, layout
);
1056 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1057 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1058 ? elfcpp::R_386_TLS_TPOFF32
1059 : elfcpp::R_386_TLS_TPOFF
);
1060 got
->add_local_with_rel(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
1061 target
->rel_dyn_section(layout
),
1064 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1065 unsupported_reloc_local(object
, r_type
);
1068 case elfcpp::R_386_TLS_LE
: // Local-exec
1069 case elfcpp::R_386_TLS_LE_32
:
1070 layout
->set_has_static_tls();
1071 if (output_is_shared
)
1073 // We need to create a dynamic relocation.
1074 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1075 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1076 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1077 ? elfcpp::R_386_TLS_TPOFF32
1078 : elfcpp::R_386_TLS_TPOFF
);
1079 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1080 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1081 data_shndx
, reloc
.get_r_offset());
1091 case elfcpp::R_386_32PLT
:
1092 case elfcpp::R_386_TLS_GD_32
:
1093 case elfcpp::R_386_TLS_GD_PUSH
:
1094 case elfcpp::R_386_TLS_GD_CALL
:
1095 case elfcpp::R_386_TLS_GD_POP
:
1096 case elfcpp::R_386_TLS_LDM_32
:
1097 case elfcpp::R_386_TLS_LDM_PUSH
:
1098 case elfcpp::R_386_TLS_LDM_CALL
:
1099 case elfcpp::R_386_TLS_LDM_POP
:
1100 case elfcpp::R_386_USED_BY_INTEL_200
:
1102 unsupported_reloc_local(object
, r_type
);
1107 // Report an unsupported relocation against a global symbol.
1110 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1111 unsigned int r_type
,
1114 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1115 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1118 // Scan a relocation for a global symbol.
1121 Target_i386::Scan::global(const General_options
& options
,
1122 Symbol_table
* symtab
,
1124 Target_i386
* target
,
1125 Sized_relobj
<32, false>* object
,
1126 unsigned int data_shndx
,
1127 Output_section
* output_section
,
1128 const elfcpp::Rel
<32, false>& reloc
,
1129 unsigned int r_type
,
1134 case elfcpp::R_386_NONE
:
1135 case elfcpp::R_386_GNU_VTINHERIT
:
1136 case elfcpp::R_386_GNU_VTENTRY
:
1139 case elfcpp::R_386_32
:
1140 case elfcpp::R_386_16
:
1141 case elfcpp::R_386_8
:
1143 // Make a PLT entry if necessary.
1144 if (gsym
->needs_plt_entry())
1146 target
->make_plt_entry(symtab
, layout
, gsym
);
1147 // Since this is not a PC-relative relocation, we may be
1148 // taking the address of a function. In that case we need to
1149 // set the entry in the dynamic symbol table to the address of
1151 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1152 gsym
->set_needs_dynsym_value();
1154 // Make a dynamic relocation if necessary.
1155 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1157 if (target
->may_need_copy_reloc(gsym
))
1159 target
->copy_reloc(&options
, symtab
, layout
, object
,
1160 data_shndx
, output_section
, gsym
, reloc
);
1162 else if (r_type
== elfcpp::R_386_32
1163 && gsym
->can_use_relative_reloc(false))
1165 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1166 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1167 output_section
, object
,
1168 data_shndx
, reloc
.get_r_offset());
1172 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1173 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1174 data_shndx
, reloc
.get_r_offset());
1180 case elfcpp::R_386_PC32
:
1181 case elfcpp::R_386_PC16
:
1182 case elfcpp::R_386_PC8
:
1184 // Make a PLT entry if necessary.
1185 if (gsym
->needs_plt_entry())
1187 // These relocations are used for function calls only in
1188 // non-PIC code. For a 32-bit relocation in a shared library,
1189 // we'll need a text relocation anyway, so we can skip the
1190 // PLT entry and let the dynamic linker bind the call directly
1191 // to the target. For smaller relocations, we should use a
1192 // PLT entry to ensure that the call can reach.
1193 if (!parameters
->options().shared()
1194 || r_type
!= elfcpp::R_386_PC32
)
1195 target
->make_plt_entry(symtab
, layout
, gsym
);
1197 // Make a dynamic relocation if necessary.
1198 int flags
= Symbol::NON_PIC_REF
;
1199 if (gsym
->type() == elfcpp::STT_FUNC
)
1200 flags
|= Symbol::FUNCTION_CALL
;
1201 if (gsym
->needs_dynamic_reloc(flags
))
1203 if (target
->may_need_copy_reloc(gsym
))
1205 target
->copy_reloc(&options
, symtab
, layout
, object
,
1206 data_shndx
, output_section
, gsym
, reloc
);
1210 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1211 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1212 data_shndx
, reloc
.get_r_offset());
1218 case elfcpp::R_386_GOT32
:
1220 // The symbol requires a GOT entry.
1221 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1222 if (gsym
->final_value_is_known())
1223 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1226 // If this symbol is not fully resolved, we need to add a
1227 // GOT entry with a dynamic relocation.
1228 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1229 if (gsym
->is_from_dynobj()
1230 || gsym
->is_undefined()
1231 || gsym
->is_preemptible())
1232 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1233 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1236 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1237 rel_dyn
->add_global_relative(
1238 gsym
, elfcpp::R_386_RELATIVE
, got
,
1239 gsym
->got_offset(GOT_TYPE_STANDARD
));
1245 case elfcpp::R_386_PLT32
:
1246 // If the symbol is fully resolved, this is just a PC32 reloc.
1247 // Otherwise we need a PLT entry.
1248 if (gsym
->final_value_is_known())
1250 // If building a shared library, we can also skip the PLT entry
1251 // if the symbol is defined in the output file and is protected
1253 if (gsym
->is_defined()
1254 && !gsym
->is_from_dynobj()
1255 && !gsym
->is_preemptible())
1257 target
->make_plt_entry(symtab
, layout
, gsym
);
1260 case elfcpp::R_386_GOTOFF
:
1261 case elfcpp::R_386_GOTPC
:
1262 // We need a GOT section.
1263 target
->got_section(symtab
, layout
);
1266 // These are relocations which should only be seen by the
1267 // dynamic linker, and should never be seen here.
1268 case elfcpp::R_386_COPY
:
1269 case elfcpp::R_386_GLOB_DAT
:
1270 case elfcpp::R_386_JUMP_SLOT
:
1271 case elfcpp::R_386_RELATIVE
:
1272 case elfcpp::R_386_TLS_TPOFF
:
1273 case elfcpp::R_386_TLS_DTPMOD32
:
1274 case elfcpp::R_386_TLS_DTPOFF32
:
1275 case elfcpp::R_386_TLS_TPOFF32
:
1276 case elfcpp::R_386_TLS_DESC
:
1277 gold_error(_("%s: unexpected reloc %u in object file"),
1278 object
->name().c_str(), r_type
);
1281 // These are initial tls relocs, which are expected when
1283 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1284 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1285 case elfcpp::R_386_TLS_DESC_CALL
:
1286 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1287 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1288 case elfcpp::R_386_TLS_IE
: // Initial-exec
1289 case elfcpp::R_386_TLS_IE_32
:
1290 case elfcpp::R_386_TLS_GOTIE
:
1291 case elfcpp::R_386_TLS_LE
: // Local-exec
1292 case elfcpp::R_386_TLS_LE_32
:
1294 const bool is_final
= gsym
->final_value_is_known();
1295 const tls::Tls_optimization optimized_type
1296 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1299 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1300 if (optimized_type
== tls::TLSOPT_NONE
)
1302 // Create a pair of GOT entries for the module index and
1303 // dtv-relative offset.
1304 Output_data_got
<32, false>* got
1305 = target
->got_section(symtab
, layout
);
1306 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1307 target
->rel_dyn_section(layout
),
1308 elfcpp::R_386_TLS_DTPMOD32
,
1309 elfcpp::R_386_TLS_DTPOFF32
);
1311 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1313 // Create a GOT entry for the tp-relative offset.
1314 Output_data_got
<32, false>* got
1315 = target
->got_section(symtab
, layout
);
1316 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
1317 target
->rel_dyn_section(layout
),
1318 elfcpp::R_386_TLS_TPOFF32
);
1320 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1321 unsupported_reloc_global(object
, r_type
, gsym
);
1324 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1325 case elfcpp::R_386_TLS_DESC_CALL
:
1326 // FIXME: If not relaxing to LE, we need to generate
1327 // a GOT entry with an R_386_TLS_DESC reloc.
1328 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1329 unsupported_reloc_global(object
, r_type
, gsym
);
1330 unsupported_reloc_global(object
, r_type
, gsym
);
1333 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1334 if (optimized_type
== tls::TLSOPT_NONE
)
1336 // Create a GOT entry for the module index.
1337 target
->got_mod_index_entry(symtab
, layout
, object
);
1339 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1340 unsupported_reloc_global(object
, r_type
, gsym
);
1343 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1346 case elfcpp::R_386_TLS_IE
: // Initial-exec
1347 case elfcpp::R_386_TLS_IE_32
:
1348 case elfcpp::R_386_TLS_GOTIE
:
1349 layout
->set_has_static_tls();
1350 if (optimized_type
== tls::TLSOPT_NONE
)
1352 // For the R_386_TLS_IE relocation, we need to create a
1353 // dynamic relocation when building a shared library.
1354 if (r_type
== elfcpp::R_386_TLS_IE
1355 && parameters
->options().shared())
1357 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1358 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1359 output_section
, object
,
1361 reloc
.get_r_offset());
1363 // Create a GOT entry for the tp-relative offset.
1364 Output_data_got
<32, false>* got
1365 = target
->got_section(symtab
, layout
);
1366 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1367 ? elfcpp::R_386_TLS_TPOFF32
1368 : elfcpp::R_386_TLS_TPOFF
);
1369 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
1370 target
->rel_dyn_section(layout
),
1373 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1374 unsupported_reloc_global(object
, r_type
, gsym
);
1377 case elfcpp::R_386_TLS_LE
: // Local-exec
1378 case elfcpp::R_386_TLS_LE_32
:
1379 layout
->set_has_static_tls();
1380 if (parameters
->options().shared())
1382 // We need to create a dynamic relocation.
1383 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1384 ? elfcpp::R_386_TLS_TPOFF32
1385 : elfcpp::R_386_TLS_TPOFF
);
1386 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1387 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1388 data_shndx
, reloc
.get_r_offset());
1398 case elfcpp::R_386_32PLT
:
1399 case elfcpp::R_386_TLS_GD_32
:
1400 case elfcpp::R_386_TLS_GD_PUSH
:
1401 case elfcpp::R_386_TLS_GD_CALL
:
1402 case elfcpp::R_386_TLS_GD_POP
:
1403 case elfcpp::R_386_TLS_LDM_32
:
1404 case elfcpp::R_386_TLS_LDM_PUSH
:
1405 case elfcpp::R_386_TLS_LDM_CALL
:
1406 case elfcpp::R_386_TLS_LDM_POP
:
1407 case elfcpp::R_386_USED_BY_INTEL_200
:
1409 unsupported_reloc_global(object
, r_type
, gsym
);
1414 // Scan relocations for a section.
1417 Target_i386::scan_relocs(const General_options
& options
,
1418 Symbol_table
* symtab
,
1420 Sized_relobj
<32, false>* object
,
1421 unsigned int data_shndx
,
1422 unsigned int sh_type
,
1423 const unsigned char* prelocs
,
1425 Output_section
* output_section
,
1426 bool needs_special_offset_handling
,
1427 size_t local_symbol_count
,
1428 const unsigned char* plocal_symbols
)
1430 if (sh_type
== elfcpp::SHT_RELA
)
1432 gold_error(_("%s: unsupported RELA reloc section"),
1433 object
->name().c_str());
1437 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1448 needs_special_offset_handling
,
1453 // Finalize the sections.
1456 Target_i386::do_finalize_sections(Layout
* layout
)
1458 // Fill in some more dynamic tags.
1459 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1462 if (this->got_plt_
!= NULL
)
1463 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1465 if (this->plt_
!= NULL
)
1467 const Output_data
* od
= this->plt_
->rel_plt();
1468 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1469 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1470 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
1473 if (this->rel_dyn_
!= NULL
)
1475 const Output_data
* od
= this->rel_dyn_
;
1476 odyn
->add_section_address(elfcpp::DT_REL
, od
);
1477 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
1478 odyn
->add_constant(elfcpp::DT_RELENT
,
1479 elfcpp::Elf_sizes
<32>::rel_size
);
1482 if (!parameters
->options().shared())
1484 // The value of the DT_DEBUG tag is filled in by the dynamic
1485 // linker at run time, and used by the debugger.
1486 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1490 // Emit any relocs we saved in an attempt to avoid generating COPY
1492 if (this->copy_relocs_
== NULL
)
1494 if (this->copy_relocs_
->any_to_emit())
1496 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1497 this->copy_relocs_
->emit(rel_dyn
);
1499 delete this->copy_relocs_
;
1500 this->copy_relocs_
= NULL
;
1503 // Return whether a direct absolute static relocation needs to be applied.
1504 // In cases where Scan::local() or Scan::global() has created
1505 // a dynamic relocation other than R_386_RELATIVE, the addend
1506 // of the relocation is carried in the data, and we must not
1507 // apply the static relocation.
1510 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1514 // For local symbols, we will have created a non-RELATIVE dynamic
1515 // relocation only if (a) the output is position independent,
1516 // (b) the relocation is absolute (not pc- or segment-relative), and
1517 // (c) the relocation is not 32 bits wide.
1519 return !(parameters
->options().output_is_position_independent()
1520 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1523 // For global symbols, we use the same helper routines used in the
1524 // scan pass. If we did not create a dynamic relocation, or if we
1525 // created a RELATIVE dynamic relocation, we should apply the static
1527 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1528 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1529 && gsym
->can_use_relative_reloc(ref_flags
1530 & Symbol::FUNCTION_CALL
);
1531 return !has_dyn
|| is_rel
;
1534 // Perform a relocation.
1537 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1538 Target_i386
* target
,
1540 const elfcpp::Rel
<32, false>& rel
,
1541 unsigned int r_type
,
1542 const Sized_symbol
<32>* gsym
,
1543 const Symbol_value
<32>* psymval
,
1544 unsigned char* view
,
1545 elfcpp::Elf_types
<32>::Elf_Addr address
,
1546 section_size_type view_size
)
1548 if (this->skip_call_tls_get_addr_
)
1550 if (r_type
!= elfcpp::R_386_PLT32
1552 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1553 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1554 _("missing expected TLS relocation"));
1557 this->skip_call_tls_get_addr_
= false;
1562 // Pick the value to use for symbols defined in shared objects.
1563 Symbol_value
<32> symval
;
1564 bool is_nonpic
= (r_type
== elfcpp::R_386_PC8
1565 || r_type
== elfcpp::R_386_PC16
1566 || r_type
== elfcpp::R_386_PC32
);
1568 && (gsym
->is_from_dynobj()
1569 || (parameters
->options().shared()
1570 && (gsym
->is_undefined() || gsym
->is_preemptible())))
1571 && gsym
->has_plt_offset()
1572 && (!is_nonpic
|| !parameters
->options().shared()))
1574 symval
.set_output_value(target
->plt_section()->address()
1575 + gsym
->plt_offset());
1579 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1581 // Get the GOT offset if needed.
1582 // The GOT pointer points to the end of the GOT section.
1583 // We need to subtract the size of the GOT section to get
1584 // the actual offset to use in the relocation.
1585 bool have_got_offset
= false;
1586 unsigned int got_offset
= 0;
1589 case elfcpp::R_386_GOT32
:
1592 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1593 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1594 - target
->got_size());
1598 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1599 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1600 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1601 - target
->got_size());
1603 have_got_offset
= true;
1612 case elfcpp::R_386_NONE
:
1613 case elfcpp::R_386_GNU_VTINHERIT
:
1614 case elfcpp::R_386_GNU_VTENTRY
:
1617 case elfcpp::R_386_32
:
1618 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true))
1619 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1622 case elfcpp::R_386_PC32
:
1624 int ref_flags
= Symbol::NON_PIC_REF
;
1625 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1626 ref_flags
|= Symbol::FUNCTION_CALL
;
1627 if (should_apply_static_reloc(gsym
, ref_flags
, true))
1628 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1632 case elfcpp::R_386_16
:
1633 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1634 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1637 case elfcpp::R_386_PC16
:
1639 int ref_flags
= Symbol::NON_PIC_REF
;
1640 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1641 ref_flags
|= Symbol::FUNCTION_CALL
;
1642 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1643 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1647 case elfcpp::R_386_8
:
1648 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false))
1649 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1652 case elfcpp::R_386_PC8
:
1654 int ref_flags
= Symbol::NON_PIC_REF
;
1655 if (gsym
!= NULL
&& gsym
->type() == elfcpp::STT_FUNC
)
1656 ref_flags
|= Symbol::FUNCTION_CALL
;
1657 if (should_apply_static_reloc(gsym
, ref_flags
, false))
1658 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1662 case elfcpp::R_386_PLT32
:
1663 gold_assert(gsym
== NULL
1664 || gsym
->has_plt_offset()
1665 || gsym
->final_value_is_known()
1666 || (gsym
->is_defined()
1667 && !gsym
->is_from_dynobj()
1668 && !gsym
->is_preemptible()));
1669 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1672 case elfcpp::R_386_GOT32
:
1673 gold_assert(have_got_offset
);
1674 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1677 case elfcpp::R_386_GOTOFF
:
1679 elfcpp::Elf_types
<32>::Elf_Addr value
;
1680 value
= (psymval
->value(object
, 0)
1681 - target
->got_plt_section()->address());
1682 Relocate_functions
<32, false>::rel32(view
, value
);
1686 case elfcpp::R_386_GOTPC
:
1688 elfcpp::Elf_types
<32>::Elf_Addr value
;
1689 value
= target
->got_plt_section()->address();
1690 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1694 case elfcpp::R_386_COPY
:
1695 case elfcpp::R_386_GLOB_DAT
:
1696 case elfcpp::R_386_JUMP_SLOT
:
1697 case elfcpp::R_386_RELATIVE
:
1698 // These are outstanding tls relocs, which are unexpected when
1700 case elfcpp::R_386_TLS_TPOFF
:
1701 case elfcpp::R_386_TLS_DTPMOD32
:
1702 case elfcpp::R_386_TLS_DTPOFF32
:
1703 case elfcpp::R_386_TLS_TPOFF32
:
1704 case elfcpp::R_386_TLS_DESC
:
1705 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1706 _("unexpected reloc %u in object file"),
1710 // These are initial tls relocs, which are expected when
1712 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1713 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1714 case elfcpp::R_386_TLS_DESC_CALL
:
1715 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1716 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1717 case elfcpp::R_386_TLS_IE
: // Initial-exec
1718 case elfcpp::R_386_TLS_IE_32
:
1719 case elfcpp::R_386_TLS_GOTIE
:
1720 case elfcpp::R_386_TLS_LE
: // Local-exec
1721 case elfcpp::R_386_TLS_LE_32
:
1722 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1723 view
, address
, view_size
);
1726 case elfcpp::R_386_32PLT
:
1727 case elfcpp::R_386_TLS_GD_32
:
1728 case elfcpp::R_386_TLS_GD_PUSH
:
1729 case elfcpp::R_386_TLS_GD_CALL
:
1730 case elfcpp::R_386_TLS_GD_POP
:
1731 case elfcpp::R_386_TLS_LDM_32
:
1732 case elfcpp::R_386_TLS_LDM_PUSH
:
1733 case elfcpp::R_386_TLS_LDM_CALL
:
1734 case elfcpp::R_386_TLS_LDM_POP
:
1735 case elfcpp::R_386_USED_BY_INTEL_200
:
1737 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1738 _("unsupported reloc %u"),
1746 // Perform a TLS relocation.
1749 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1750 Target_i386
* target
,
1752 const elfcpp::Rel
<32, false>& rel
,
1753 unsigned int r_type
,
1754 const Sized_symbol
<32>* gsym
,
1755 const Symbol_value
<32>* psymval
,
1756 unsigned char* view
,
1757 elfcpp::Elf_types
<32>::Elf_Addr
,
1758 section_size_type view_size
)
1760 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1762 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1764 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1766 const bool is_final
=
1768 ? !parameters
->options().output_is_position_independent()
1769 : gsym
->final_value_is_known());
1770 const tls::Tls_optimization optimized_type
1771 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1774 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1775 if (optimized_type
== tls::TLSOPT_TO_LE
)
1777 gold_assert(tls_segment
!= NULL
);
1778 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1779 rel
, r_type
, value
, view
,
1785 unsigned int got_offset
;
1788 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_PAIR
));
1789 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_PAIR
)
1790 - target
->got_size());
1794 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1795 gold_assert(object
->local_has_got_offset(r_sym
,
1796 GOT_TYPE_TLS_PAIR
));
1797 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_PAIR
)
1798 - target
->got_size());
1800 if (optimized_type
== tls::TLSOPT_TO_IE
)
1802 gold_assert(tls_segment
!= NULL
);
1803 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1804 got_offset
, view
, view_size
);
1807 else if (optimized_type
== tls::TLSOPT_NONE
)
1809 // Relocate the field with the offset of the pair of GOT
1811 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1815 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1816 _("unsupported reloc %u"),
1820 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1821 case elfcpp::R_386_TLS_DESC_CALL
:
1822 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1823 _("unsupported reloc %u"),
1827 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1828 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
1830 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1831 _("both SUN and GNU model "
1832 "TLS relocations"));
1835 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1836 if (optimized_type
== tls::TLSOPT_TO_LE
)
1838 gold_assert(tls_segment
!= NULL
);
1839 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1840 value
, view
, view_size
);
1843 else if (optimized_type
== tls::TLSOPT_NONE
)
1845 // Relocate the field with the offset of the GOT entry for
1846 // the module index.
1847 unsigned int got_offset
;
1848 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
1849 - target
->got_size());
1850 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1853 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1854 _("unsupported reloc %u"),
1858 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1859 // This reloc can appear in debugging sections, in which case we
1860 // won't see the TLS_LDM reloc. The local_dynamic_type field
1862 if (optimized_type
== tls::TLSOPT_TO_LE
)
1864 gold_assert(tls_segment
!= NULL
);
1865 value
-= tls_segment
->memsz();
1867 Relocate_functions
<32, false>::rel32(view
, value
);
1870 case elfcpp::R_386_TLS_IE
: // Initial-exec
1871 case elfcpp::R_386_TLS_GOTIE
:
1872 case elfcpp::R_386_TLS_IE_32
:
1873 if (optimized_type
== tls::TLSOPT_TO_LE
)
1875 gold_assert(tls_segment
!= NULL
);
1876 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1877 rel
, r_type
, value
, view
,
1881 else if (optimized_type
== tls::TLSOPT_NONE
)
1883 // Relocate the field with the offset of the GOT entry for
1884 // the tp-relative offset of the symbol.
1885 unsigned int got_offset
;
1888 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
1889 got_offset
= gsym
->got_offset(GOT_TYPE_TLS_OFFSET
);
1893 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1894 gold_assert(object
->local_has_got_offset(r_sym
,
1895 GOT_TYPE_TLS_OFFSET
));
1896 got_offset
= object
->local_got_offset(r_sym
,
1897 GOT_TYPE_TLS_OFFSET
);
1899 // For the R_386_TLS_IE relocation, we need to apply the
1900 // absolute address of the GOT entry.
1901 if (r_type
== elfcpp::R_386_TLS_IE
)
1902 got_offset
+= target
->got_plt_section()->address();
1903 // All GOT offsets are relative to the end of the GOT.
1904 got_offset
-= target
->got_size();
1905 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1908 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1909 _("unsupported reloc %u"),
1913 case elfcpp::R_386_TLS_LE
: // Local-exec
1914 // If we're creating a shared library, a dynamic relocation will
1915 // have been created for this location, so do not apply it now.
1916 if (!parameters
->options().shared())
1918 gold_assert(tls_segment
!= NULL
);
1919 value
-= tls_segment
->memsz();
1920 Relocate_functions
<32, false>::rel32(view
, value
);
1924 case elfcpp::R_386_TLS_LE_32
:
1925 // If we're creating a shared library, a dynamic relocation will
1926 // have been created for this location, so do not apply it now.
1927 if (!parameters
->options().shared())
1929 gold_assert(tls_segment
!= NULL
);
1930 value
= tls_segment
->memsz() - value
;
1931 Relocate_functions
<32, false>::rel32(view
, value
);
1937 // Do a relocation in which we convert a TLS General-Dynamic to a
1941 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
1943 Output_segment
* tls_segment
,
1944 const elfcpp::Rel
<32, false>& rel
,
1946 elfcpp::Elf_types
<32>::Elf_Addr value
,
1947 unsigned char* view
,
1948 section_size_type view_size
)
1950 // leal foo(,%reg,1),%eax; call ___tls_get_addr
1951 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1952 // leal foo(%reg),%eax; call ___tls_get_addr
1953 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1955 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
1956 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
1958 unsigned char op1
= view
[-1];
1959 unsigned char op2
= view
[-2];
1961 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
1962 op2
== 0x8d || op2
== 0x04);
1963 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
1969 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
1970 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
1971 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
1972 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
1973 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1977 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
1978 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
1979 if (rel
.get_r_offset() + 9 < view_size
1982 // There is a trailing nop. Use the size byte subl.
1983 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1988 // Use the five byte subl.
1989 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1993 value
= tls_segment
->memsz() - value
;
1994 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
1996 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1998 this->skip_call_tls_get_addr_
= true;
2001 // Do a relocation in which we convert a TLS General-Dynamic to an
2005 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2007 Output_segment
* tls_segment
,
2008 const elfcpp::Rel
<32, false>& rel
,
2010 elfcpp::Elf_types
<32>::Elf_Addr value
,
2011 unsigned char* view
,
2012 section_size_type view_size
)
2014 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2015 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2017 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2018 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2020 unsigned char op1
= view
[-1];
2021 unsigned char op2
= view
[-2];
2023 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2024 op2
== 0x8d || op2
== 0x04);
2025 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2029 // FIXME: For now, support only one form.
2030 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2031 op1
== 0x8d && op2
== 0x04);
2035 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2036 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2037 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2038 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2039 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2043 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2044 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2045 if (rel
.get_r_offset() + 9 < view_size
2048 // FIXME: This is not the right instruction sequence.
2049 // There is a trailing nop. Use the size byte subl.
2050 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2055 // FIXME: This is not the right instruction sequence.
2056 // Use the five byte subl.
2057 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2061 value
= tls_segment
->memsz() - value
;
2062 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2064 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2066 this->skip_call_tls_get_addr_
= true;
2069 // Do a relocation in which we convert a TLS Local-Dynamic to a
2073 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2076 const elfcpp::Rel
<32, false>& rel
,
2078 elfcpp::Elf_types
<32>::Elf_Addr
,
2079 unsigned char* view
,
2080 section_size_type view_size
)
2082 // leal foo(%reg), %eax; call ___tls_get_addr
2083 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2085 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2086 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2088 // FIXME: Does this test really always pass?
2089 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2090 view
[-2] == 0x8d && view
[-1] == 0x83);
2092 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2094 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2096 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2098 this->skip_call_tls_get_addr_
= true;
2101 // Do a relocation in which we convert a TLS Initial-Exec to a
2105 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2107 Output_segment
* tls_segment
,
2108 const elfcpp::Rel
<32, false>& rel
,
2109 unsigned int r_type
,
2110 elfcpp::Elf_types
<32>::Elf_Addr value
,
2111 unsigned char* view
,
2112 section_size_type view_size
)
2114 // We have to actually change the instructions, which means that we
2115 // need to examine the opcodes to figure out which instruction we
2117 if (r_type
== elfcpp::R_386_TLS_IE
)
2119 // movl %gs:XX,%eax ==> movl $YY,%eax
2120 // movl %gs:XX,%reg ==> movl $YY,%reg
2121 // addl %gs:XX,%reg ==> addl $YY,%reg
2122 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2123 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2125 unsigned char op1
= view
[-1];
2128 // movl XX,%eax ==> movl $YY,%eax
2133 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2135 unsigned char op2
= view
[-2];
2138 // movl XX,%reg ==> movl $YY,%reg
2139 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2140 (op1
& 0xc7) == 0x05);
2142 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2144 else if (op2
== 0x03)
2146 // addl XX,%reg ==> addl $YY,%reg
2147 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2148 (op1
& 0xc7) == 0x05);
2150 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2153 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2158 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2159 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2160 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2161 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2162 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2164 unsigned char op1
= view
[-1];
2165 unsigned char op2
= view
[-2];
2166 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2167 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2170 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2172 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2174 else if (op2
== 0x2b)
2176 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2178 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2180 else if (op2
== 0x03)
2182 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2184 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2187 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2190 value
= tls_segment
->memsz() - value
;
2191 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2194 Relocate_functions
<32, false>::rel32(view
, value
);
2197 // Relocate section data.
2200 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2201 unsigned int sh_type
,
2202 const unsigned char* prelocs
,
2204 Output_section
* output_section
,
2205 bool needs_special_offset_handling
,
2206 unsigned char* view
,
2207 elfcpp::Elf_types
<32>::Elf_Addr address
,
2208 section_size_type view_size
)
2210 gold_assert(sh_type
== elfcpp::SHT_REL
);
2212 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2213 Target_i386::Relocate
>(
2219 needs_special_offset_handling
,
2225 // Return the size of a relocation while scanning during a relocatable
2229 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2230 unsigned int r_type
,
2235 case elfcpp::R_386_NONE
:
2236 case elfcpp::R_386_GNU_VTINHERIT
:
2237 case elfcpp::R_386_GNU_VTENTRY
:
2238 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2239 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2240 case elfcpp::R_386_TLS_DESC_CALL
:
2241 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2242 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2243 case elfcpp::R_386_TLS_IE
: // Initial-exec
2244 case elfcpp::R_386_TLS_IE_32
:
2245 case elfcpp::R_386_TLS_GOTIE
:
2246 case elfcpp::R_386_TLS_LE
: // Local-exec
2247 case elfcpp::R_386_TLS_LE_32
:
2250 case elfcpp::R_386_32
:
2251 case elfcpp::R_386_PC32
:
2252 case elfcpp::R_386_GOT32
:
2253 case elfcpp::R_386_PLT32
:
2254 case elfcpp::R_386_GOTOFF
:
2255 case elfcpp::R_386_GOTPC
:
2258 case elfcpp::R_386_16
:
2259 case elfcpp::R_386_PC16
:
2262 case elfcpp::R_386_8
:
2263 case elfcpp::R_386_PC8
:
2266 // These are relocations which should only be seen by the
2267 // dynamic linker, and should never be seen here.
2268 case elfcpp::R_386_COPY
:
2269 case elfcpp::R_386_GLOB_DAT
:
2270 case elfcpp::R_386_JUMP_SLOT
:
2271 case elfcpp::R_386_RELATIVE
:
2272 case elfcpp::R_386_TLS_TPOFF
:
2273 case elfcpp::R_386_TLS_DTPMOD32
:
2274 case elfcpp::R_386_TLS_DTPOFF32
:
2275 case elfcpp::R_386_TLS_TPOFF32
:
2276 case elfcpp::R_386_TLS_DESC
:
2277 object
->error(_("unexpected reloc %u in object file"), r_type
);
2280 case elfcpp::R_386_32PLT
:
2281 case elfcpp::R_386_TLS_GD_32
:
2282 case elfcpp::R_386_TLS_GD_PUSH
:
2283 case elfcpp::R_386_TLS_GD_CALL
:
2284 case elfcpp::R_386_TLS_GD_POP
:
2285 case elfcpp::R_386_TLS_LDM_32
:
2286 case elfcpp::R_386_TLS_LDM_PUSH
:
2287 case elfcpp::R_386_TLS_LDM_CALL
:
2288 case elfcpp::R_386_TLS_LDM_POP
:
2289 case elfcpp::R_386_USED_BY_INTEL_200
:
2291 object
->error(_("unsupported reloc %u in object file"), r_type
);
2296 // Scan the relocs during a relocatable link.
2299 Target_i386::scan_relocatable_relocs(const General_options
& options
,
2300 Symbol_table
* symtab
,
2302 Sized_relobj
<32, false>* object
,
2303 unsigned int data_shndx
,
2304 unsigned int sh_type
,
2305 const unsigned char* prelocs
,
2307 Output_section
* output_section
,
2308 bool needs_special_offset_handling
,
2309 size_t local_symbol_count
,
2310 const unsigned char* plocal_symbols
,
2311 Relocatable_relocs
* rr
)
2313 gold_assert(sh_type
== elfcpp::SHT_REL
);
2315 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2316 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2318 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2319 Scan_relocatable_relocs
>(
2328 needs_special_offset_handling
,
2334 // Relocate a section during a relocatable link.
2337 Target_i386::relocate_for_relocatable(
2338 const Relocate_info
<32, false>* relinfo
,
2339 unsigned int sh_type
,
2340 const unsigned char* prelocs
,
2342 Output_section
* output_section
,
2343 off_t offset_in_output_section
,
2344 const Relocatable_relocs
* rr
,
2345 unsigned char* view
,
2346 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2347 section_size_type view_size
,
2348 unsigned char* reloc_view
,
2349 section_size_type reloc_view_size
)
2351 gold_assert(sh_type
== elfcpp::SHT_REL
);
2353 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2358 offset_in_output_section
,
2367 // Return the value to use for a dynamic which requires special
2368 // treatment. This is how we support equality comparisons of function
2369 // pointers across shared library boundaries, as described in the
2370 // processor specific ABI supplement.
2373 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2375 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2376 return this->plt_section()->address() + gsym
->plt_offset();
2379 // Return a string used to fill a code section with nops to take up
2380 // the specified length.
2383 Target_i386::do_code_fill(section_size_type length
) const
2387 // Build a jmp instruction to skip over the bytes.
2388 unsigned char jmp
[5];
2390 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2391 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2392 + std::string(length
- 5, '\0'));
2395 // Nop sequences of various lengths.
2396 const char nop1
[1] = { 0x90 }; // nop
2397 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2398 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2399 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2400 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2401 0x00 }; // leal 0(%esi,1),%esi
2402 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2404 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2406 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2407 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2408 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2409 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2411 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2412 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2414 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2415 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2417 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2418 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2419 0x00, 0x00, 0x00, 0x00 };
2420 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2421 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2422 0x27, 0x00, 0x00, 0x00,
2424 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2425 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2426 0xbc, 0x27, 0x00, 0x00,
2428 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2429 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2430 0x90, 0x90, 0x90, 0x90,
2433 const char* nops
[16] = {
2435 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2436 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2439 return std::string(nops
[length
], length
);
2442 // The selector for i386 object files.
2444 class Target_selector_i386
: public Target_selector
2447 Target_selector_i386()
2448 : Target_selector(elfcpp::EM_386
, 32, false, "elf32-i386")
2452 do_instantiate_target()
2453 { return new Target_i386(); }
2456 Target_selector_i386 target_selector_i386
;
2458 } // End anonymous namespace.