1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009 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"
48 class Output_data_plt_i386
;
50 // The i386 target class.
51 // TLS info comes from
52 // http://people.redhat.com/drepper/tls.pdf
53 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
55 class Target_i386
: public Target_freebsd
<32, false>
58 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
61 : Target_freebsd
<32, false>(&i386_info
),
62 got_(NULL
), plt_(NULL
), got_plt_(NULL
), global_offset_table_(NULL
),
63 rel_dyn_(NULL
), copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
64 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
67 // Process the relocations to determine unreferenced sections for
68 // garbage collection.
70 gc_process_relocs(Symbol_table
* symtab
,
72 Sized_relobj
<32, false>* object
,
73 unsigned int data_shndx
,
75 const unsigned char* prelocs
,
77 Output_section
* output_section
,
78 bool needs_special_offset_handling
,
79 size_t local_symbol_count
,
80 const unsigned char* plocal_symbols
);
82 // Scan the relocations to look for symbol adjustments.
84 scan_relocs(Symbol_table
* symtab
,
86 Sized_relobj
<32, false>* object
,
87 unsigned int data_shndx
,
89 const unsigned char* prelocs
,
91 Output_section
* output_section
,
92 bool needs_special_offset_handling
,
93 size_t local_symbol_count
,
94 const unsigned char* plocal_symbols
);
96 // Finalize the sections.
98 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
100 // Return the value to use for a dynamic which requires special
103 do_dynsym_value(const Symbol
*) const;
105 // Relocate a section.
107 relocate_section(const Relocate_info
<32, false>*,
108 unsigned int sh_type
,
109 const unsigned char* prelocs
,
111 Output_section
* output_section
,
112 bool needs_special_offset_handling
,
114 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
115 section_size_type view_size
,
116 const Reloc_symbol_changes
*);
118 // Scan the relocs during a relocatable link.
120 scan_relocatable_relocs(Symbol_table
* symtab
,
122 Sized_relobj
<32, false>* object
,
123 unsigned int data_shndx
,
124 unsigned int sh_type
,
125 const unsigned char* prelocs
,
127 Output_section
* output_section
,
128 bool needs_special_offset_handling
,
129 size_t local_symbol_count
,
130 const unsigned char* plocal_symbols
,
131 Relocatable_relocs
*);
133 // Relocate a section during a relocatable link.
135 relocate_for_relocatable(const Relocate_info
<32, false>*,
136 unsigned int sh_type
,
137 const unsigned char* prelocs
,
139 Output_section
* output_section
,
140 off_t offset_in_output_section
,
141 const Relocatable_relocs
*,
143 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
144 section_size_type view_size
,
145 unsigned char* reloc_view
,
146 section_size_type reloc_view_size
);
148 // Return a string used to fill a code section with nops.
150 do_code_fill(section_size_type length
) const;
152 // Return whether SYM is defined by the ABI.
154 do_is_defined_by_abi(const Symbol
* sym
) const
155 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
157 // Return whether a symbol name implies a local label. The UnixWare
158 // 2.1 cc generates temporary symbols that start with .X, so we
159 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
160 // If so, we should move the .X recognition into
161 // Target::do_is_local_label_name.
163 do_is_local_label_name(const char* name
) const
165 if (name
[0] == '.' && name
[1] == 'X')
167 return Target::do_is_local_label_name(name
);
170 // Adjust -fstack-split code which calls non-stack-split code.
172 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
173 section_offset_type fnoffset
, section_size_type fnsize
,
174 unsigned char* view
, section_size_type view_size
,
175 std::string
* from
, std::string
* to
) const;
177 // Return the size of the GOT section.
181 gold_assert(this->got_
!= NULL
);
182 return this->got_
->data_size();
186 // The class which scans relocations.
190 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
191 Sized_relobj
<32, false>* object
,
192 unsigned int data_shndx
,
193 Output_section
* output_section
,
194 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
195 const elfcpp::Sym
<32, false>& lsym
);
198 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
199 Sized_relobj
<32, false>* object
,
200 unsigned int data_shndx
,
201 Output_section
* output_section
,
202 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
206 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
209 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
213 // The class which implements relocation.
218 : skip_call_tls_get_addr_(false),
219 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
224 if (this->skip_call_tls_get_addr_
)
226 // FIXME: This needs to specify the location somehow.
227 gold_error(_("missing expected TLS relocation"));
231 // Return whether the static relocation needs to be applied.
233 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
236 Output_section
* output_section
);
238 // Do a relocation. Return false if the caller should not issue
239 // any warnings about this relocation.
241 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
242 size_t relnum
, const elfcpp::Rel
<32, false>&,
243 unsigned int r_type
, const Sized_symbol
<32>*,
244 const Symbol_value
<32>*,
245 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
249 // Do a TLS relocation.
251 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
252 size_t relnum
, const elfcpp::Rel
<32, false>&,
253 unsigned int r_type
, const Sized_symbol
<32>*,
254 const Symbol_value
<32>*,
255 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
258 // Do a TLS General-Dynamic to Initial-Exec transition.
260 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
261 Output_segment
* tls_segment
,
262 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
263 elfcpp::Elf_types
<32>::Elf_Addr value
,
265 section_size_type view_size
);
267 // Do a TLS General-Dynamic to Local-Exec transition.
269 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
270 Output_segment
* tls_segment
,
271 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
272 elfcpp::Elf_types
<32>::Elf_Addr value
,
274 section_size_type view_size
);
276 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
279 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
280 Output_segment
* tls_segment
,
281 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
282 elfcpp::Elf_types
<32>::Elf_Addr value
,
284 section_size_type view_size
);
286 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
289 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
290 Output_segment
* tls_segment
,
291 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
292 elfcpp::Elf_types
<32>::Elf_Addr value
,
294 section_size_type view_size
);
296 // Do a TLS Local-Dynamic to Local-Exec transition.
298 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
299 Output_segment
* tls_segment
,
300 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
301 elfcpp::Elf_types
<32>::Elf_Addr value
,
303 section_size_type view_size
);
305 // Do a TLS Initial-Exec to Local-Exec transition.
307 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
308 Output_segment
* tls_segment
,
309 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
310 elfcpp::Elf_types
<32>::Elf_Addr value
,
312 section_size_type view_size
);
314 // We need to keep track of which type of local dynamic relocation
315 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
316 enum Local_dynamic_type
323 // This is set if we should skip the next reloc, which should be a
324 // PLT32 reloc against ___tls_get_addr.
325 bool skip_call_tls_get_addr_
;
326 // The type of local dynamic relocation we have seen in the section
327 // being relocated, if any.
328 Local_dynamic_type local_dynamic_type_
;
331 // A class which returns the size required for a relocation type,
332 // used while scanning relocs during a relocatable link.
333 class Relocatable_size_for_reloc
337 get_size_for_reloc(unsigned int, Relobj
*);
340 // Adjust TLS relocation type based on the options and whether this
341 // is a local symbol.
342 static tls::Tls_optimization
343 optimize_tls_reloc(bool is_final
, int r_type
);
345 // Get the GOT section, creating it if necessary.
346 Output_data_got
<32, false>*
347 got_section(Symbol_table
*, Layout
*);
349 // Get the GOT PLT section.
351 got_plt_section() const
353 gold_assert(this->got_plt_
!= NULL
);
354 return this->got_plt_
;
357 // Create a PLT entry for a global symbol.
359 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
361 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
363 define_tls_base_symbol(Symbol_table
*, Layout
*);
365 // Create a GOT entry for the TLS module index.
367 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
368 Sized_relobj
<32, false>* object
);
370 // Get the PLT section.
371 Output_data_plt_i386
*
374 gold_assert(this->plt_
!= NULL
);
378 // Get the dynamic reloc section, creating it if necessary.
380 rel_dyn_section(Layout
*);
382 // Get the section to use for TLS_DESC relocations.
384 rel_tls_desc_section(Layout
*) const;
386 // Add a potential copy relocation.
388 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
389 Sized_relobj
<32, false>* object
,
390 unsigned int shndx
, Output_section
* output_section
,
391 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
393 this->copy_relocs_
.copy_reloc(symtab
, layout
,
394 symtab
->get_sized_symbol
<32>(sym
),
395 object
, shndx
, output_section
, reloc
,
396 this->rel_dyn_section(layout
));
399 // Information about this specific target which we pass to the
400 // general Target structure.
401 static const Target::Target_info i386_info
;
403 // The types of GOT entries needed for this platform.
406 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
407 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
408 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
409 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
410 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
414 Output_data_got
<32, false>* got_
;
416 Output_data_plt_i386
* plt_
;
417 // The GOT PLT section.
418 Output_data_space
* got_plt_
;
419 // The _GLOBAL_OFFSET_TABLE_ symbol.
420 Symbol
* global_offset_table_
;
421 // The dynamic reloc section.
422 Reloc_section
* rel_dyn_
;
423 // Relocs saved to avoid a COPY reloc.
424 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
425 // Space for variables copied with a COPY reloc.
426 Output_data_space
* dynbss_
;
427 // Offset of the GOT entry for the TLS module index.
428 unsigned int got_mod_index_offset_
;
429 // True if the _TLS_MODULE_BASE_ symbol has been defined.
430 bool tls_base_symbol_defined_
;
433 const Target::Target_info
Target_i386::i386_info
=
436 false, // is_big_endian
437 elfcpp::EM_386
, // machine_code
438 false, // has_make_symbol
439 false, // has_resolve
440 true, // has_code_fill
441 true, // is_default_stack_executable
443 "/usr/lib/libc.so.1", // dynamic_linker
444 0x08048000, // default_text_segment_address
445 0x1000, // abi_pagesize (overridable by -z max-page-size)
446 0x1000, // common_pagesize (overridable by -z common-page-size)
447 elfcpp::SHN_UNDEF
, // small_common_shndx
448 elfcpp::SHN_UNDEF
, // large_common_shndx
449 0, // small_common_section_flags
450 0, // large_common_section_flags
451 NULL
, // attributes_section
452 NULL
// attributes_vendor
455 // Get the GOT section, creating it if necessary.
457 Output_data_got
<32, false>*
458 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
460 if (this->got_
== NULL
)
462 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
464 this->got_
= new Output_data_got
<32, false>();
467 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
469 | elfcpp::SHF_WRITE
),
470 this->got_
, false, true, true,
473 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
474 os
= layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
476 | elfcpp::SHF_WRITE
),
477 this->got_plt_
, false, false, false,
480 // The first three entries are reserved.
481 this->got_plt_
->set_current_data_size(3 * 4);
483 // Those bytes can go into the relro segment.
484 layout
->increase_relro(3 * 4);
486 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
487 this->global_offset_table_
=
488 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
489 Symbol_table::PREDEFINED
,
491 0, 0, elfcpp::STT_OBJECT
,
493 elfcpp::STV_HIDDEN
, 0,
500 // Get the dynamic reloc section, creating it if necessary.
502 Target_i386::Reloc_section
*
503 Target_i386::rel_dyn_section(Layout
* layout
)
505 if (this->rel_dyn_
== NULL
)
507 gold_assert(layout
!= NULL
);
508 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
509 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
510 elfcpp::SHF_ALLOC
, this->rel_dyn_
, true,
511 false, false, false);
513 return this->rel_dyn_
;
516 // A class to handle the PLT data.
518 class Output_data_plt_i386
: public Output_section_data
521 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
523 Output_data_plt_i386(Layout
*, Output_data_space
*);
525 // Add an entry to the PLT.
527 add_entry(Symbol
* gsym
);
529 // Return the .rel.plt section data.
532 { return this->rel_
; }
534 // Return where the TLS_DESC relocations should go.
536 rel_tls_desc(Layout
*);
540 do_adjust_output_section(Output_section
* os
);
542 // Write to a map file.
544 do_print_to_mapfile(Mapfile
* mapfile
) const
545 { mapfile
->print_output_data(this, _("** PLT")); }
548 // The size of an entry in the PLT.
549 static const int plt_entry_size
= 16;
551 // The first entry in the PLT for an executable.
552 static unsigned char exec_first_plt_entry
[plt_entry_size
];
554 // The first entry in the PLT for a shared object.
555 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
557 // Other entries in the PLT for an executable.
558 static unsigned char exec_plt_entry
[plt_entry_size
];
560 // Other entries in the PLT for a shared object.
561 static unsigned char dyn_plt_entry
[plt_entry_size
];
563 // Set the final size.
565 set_final_data_size()
566 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
568 // Write out the PLT data.
570 do_write(Output_file
*);
572 // The reloc section.
574 // The TLS_DESC relocations, if necessary. These must follow the
575 // regular PLT relocs.
576 Reloc_section
* tls_desc_rel_
;
577 // The .got.plt section.
578 Output_data_space
* got_plt_
;
579 // The number of PLT entries.
583 // Create the PLT section. The ordinary .got section is an argument,
584 // since we need to refer to the start. We also create our own .got
585 // section just for PLT entries.
587 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
588 Output_data_space
* got_plt
)
589 : Output_section_data(4), tls_desc_rel_(NULL
), got_plt_(got_plt
), count_(0)
591 this->rel_
= new Reloc_section(false);
592 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
593 elfcpp::SHF_ALLOC
, this->rel_
, true,
594 false, false, false);
598 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
600 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
601 // linker, and so do we.
605 // Add an entry to the PLT.
608 Output_data_plt_i386::add_entry(Symbol
* gsym
)
610 gold_assert(!gsym
->has_plt_offset());
612 // Note that when setting the PLT offset we skip the initial
613 // reserved PLT entry.
614 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
618 section_offset_type got_offset
= this->got_plt_
->current_data_size();
620 // Every PLT entry needs a GOT entry which points back to the PLT
621 // entry (this will be changed by the dynamic linker, normally
622 // lazily when the function is called).
623 this->got_plt_
->set_current_data_size(got_offset
+ 4);
625 // Every PLT entry needs a reloc.
626 gsym
->set_needs_dynsym_entry();
627 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
630 // Note that we don't need to save the symbol. The contents of the
631 // PLT are independent of which symbols are used. The symbols only
632 // appear in the relocations.
635 // Return where the TLS_DESC relocations should go, creating it if
636 // necessary. These follow the JUMP_SLOT relocations.
638 Output_data_plt_i386::Reloc_section
*
639 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
641 if (this->tls_desc_rel_
== NULL
)
643 this->tls_desc_rel_
= new Reloc_section(false);
644 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
645 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
646 true, false, false, false);
647 gold_assert(this->tls_desc_rel_
->output_section() ==
648 this->rel_
->output_section());
650 return this->tls_desc_rel_
;
653 // The first entry in the PLT for an executable.
655 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
657 0xff, 0x35, // pushl contents of memory address
658 0, 0, 0, 0, // replaced with address of .got + 4
659 0xff, 0x25, // jmp indirect
660 0, 0, 0, 0, // replaced with address of .got + 8
664 // The first entry in the PLT for a shared object.
666 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
668 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
669 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
673 // Subsequent entries in the PLT for an executable.
675 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
677 0xff, 0x25, // jmp indirect
678 0, 0, 0, 0, // replaced with address of symbol in .got
679 0x68, // pushl immediate
680 0, 0, 0, 0, // replaced with offset into relocation table
681 0xe9, // jmp relative
682 0, 0, 0, 0 // replaced with offset to start of .plt
685 // Subsequent entries in the PLT for a shared object.
687 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
689 0xff, 0xa3, // jmp *offset(%ebx)
690 0, 0, 0, 0, // replaced with offset of symbol in .got
691 0x68, // pushl immediate
692 0, 0, 0, 0, // replaced with offset into relocation table
693 0xe9, // jmp relative
694 0, 0, 0, 0 // replaced with offset to start of .plt
697 // Write out the PLT. This uses the hand-coded instructions above,
698 // and adjusts them as needed. This is all specified by the i386 ELF
699 // Processor Supplement.
702 Output_data_plt_i386::do_write(Output_file
* of
)
704 const off_t offset
= this->offset();
705 const section_size_type oview_size
=
706 convert_to_section_size_type(this->data_size());
707 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
709 const off_t got_file_offset
= this->got_plt_
->offset();
710 const section_size_type got_size
=
711 convert_to_section_size_type(this->got_plt_
->data_size());
712 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
715 unsigned char* pov
= oview
;
717 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
718 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
720 if (parameters
->options().output_is_position_independent())
721 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
724 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
725 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
726 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
728 pov
+= plt_entry_size
;
730 unsigned char* got_pov
= got_view
;
732 memset(got_pov
, 0, 12);
735 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
737 unsigned int plt_offset
= plt_entry_size
;
738 unsigned int plt_rel_offset
= 0;
739 unsigned int got_offset
= 12;
740 const unsigned int count
= this->count_
;
741 for (unsigned int i
= 0;
744 pov
+= plt_entry_size
,
746 plt_offset
+= plt_entry_size
,
747 plt_rel_offset
+= rel_size
,
750 // Set and adjust the PLT entry itself.
752 if (parameters
->options().output_is_position_independent())
754 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
755 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
759 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
760 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
765 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
766 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
767 - (plt_offset
+ plt_entry_size
));
769 // Set the entry in the GOT.
770 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
773 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
774 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
776 of
->write_output_view(offset
, oview_size
, oview
);
777 of
->write_output_view(got_file_offset
, got_size
, got_view
);
780 // Create a PLT entry for a global symbol.
783 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
785 if (gsym
->has_plt_offset())
788 if (this->plt_
== NULL
)
790 // Create the GOT sections first.
791 this->got_section(symtab
, layout
);
793 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
794 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
796 | elfcpp::SHF_EXECINSTR
),
797 this->plt_
, false, false, false, false);
800 this->plt_
->add_entry(gsym
);
803 // Get the section to use for TLS_DESC relocations.
805 Target_i386::Reloc_section
*
806 Target_i386::rel_tls_desc_section(Layout
* layout
) const
808 return this->plt_section()->rel_tls_desc(layout
);
811 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
814 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
816 if (this->tls_base_symbol_defined_
)
819 Output_segment
* tls_segment
= layout
->tls_segment();
820 if (tls_segment
!= NULL
)
822 bool is_exec
= parameters
->options().output_is_executable();
823 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
824 Symbol_table::PREDEFINED
,
828 elfcpp::STV_HIDDEN
, 0,
830 ? Symbol::SEGMENT_END
831 : Symbol::SEGMENT_START
),
834 this->tls_base_symbol_defined_
= true;
837 // Create a GOT entry for the TLS module index.
840 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
841 Sized_relobj
<32, false>* object
)
843 if (this->got_mod_index_offset_
== -1U)
845 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
846 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
847 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
848 unsigned int got_offset
= got
->add_constant(0);
849 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
851 got
->add_constant(0);
852 this->got_mod_index_offset_
= got_offset
;
854 return this->got_mod_index_offset_
;
857 // Optimize the TLS relocation type based on what we know about the
858 // symbol. IS_FINAL is true if the final address of this symbol is
859 // known at link time.
861 tls::Tls_optimization
862 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
864 // If we are generating a shared library, then we can't do anything
866 if (parameters
->options().shared())
867 return tls::TLSOPT_NONE
;
871 case elfcpp::R_386_TLS_GD
:
872 case elfcpp::R_386_TLS_GOTDESC
:
873 case elfcpp::R_386_TLS_DESC_CALL
:
874 // These are General-Dynamic which permits fully general TLS
875 // access. Since we know that we are generating an executable,
876 // we can convert this to Initial-Exec. If we also know that
877 // this is a local symbol, we can further switch to Local-Exec.
879 return tls::TLSOPT_TO_LE
;
880 return tls::TLSOPT_TO_IE
;
882 case elfcpp::R_386_TLS_LDM
:
883 // This is Local-Dynamic, which refers to a local symbol in the
884 // dynamic TLS block. Since we know that we generating an
885 // executable, we can switch to Local-Exec.
886 return tls::TLSOPT_TO_LE
;
888 case elfcpp::R_386_TLS_LDO_32
:
889 // Another type of Local-Dynamic relocation.
890 return tls::TLSOPT_TO_LE
;
892 case elfcpp::R_386_TLS_IE
:
893 case elfcpp::R_386_TLS_GOTIE
:
894 case elfcpp::R_386_TLS_IE_32
:
895 // These are Initial-Exec relocs which get the thread offset
896 // from the GOT. If we know that we are linking against the
897 // local symbol, we can switch to Local-Exec, which links the
898 // thread offset into the instruction.
900 return tls::TLSOPT_TO_LE
;
901 return tls::TLSOPT_NONE
;
903 case elfcpp::R_386_TLS_LE
:
904 case elfcpp::R_386_TLS_LE_32
:
905 // When we already have Local-Exec, there is nothing further we
907 return tls::TLSOPT_NONE
;
914 // Report an unsupported relocation against a local symbol.
917 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
920 gold_error(_("%s: unsupported reloc %u against local symbol"),
921 object
->name().c_str(), r_type
);
924 // Scan a relocation for a local symbol.
927 Target_i386::Scan::local(Symbol_table
* symtab
,
930 Sized_relobj
<32, false>* object
,
931 unsigned int data_shndx
,
932 Output_section
* output_section
,
933 const elfcpp::Rel
<32, false>& reloc
,
935 const elfcpp::Sym
<32, false>& lsym
)
939 case elfcpp::R_386_NONE
:
940 case elfcpp::R_386_GNU_VTINHERIT
:
941 case elfcpp::R_386_GNU_VTENTRY
:
944 case elfcpp::R_386_32
:
945 // If building a shared library (or a position-independent
946 // executable), we need to create a dynamic relocation for
947 // this location. The relocation applied at link time will
948 // apply the link-time value, so we flag the location with
949 // an R_386_RELATIVE relocation so the dynamic loader can
950 // relocate it easily.
951 if (parameters
->options().output_is_position_independent())
953 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
954 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
955 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
956 output_section
, data_shndx
,
957 reloc
.get_r_offset());
961 case elfcpp::R_386_16
:
962 case elfcpp::R_386_8
:
963 // If building a shared library (or a position-independent
964 // executable), we need to create a dynamic relocation for
965 // this location. Because the addend needs to remain in the
966 // data section, we need to be careful not to apply this
967 // relocation statically.
968 if (parameters
->options().output_is_position_independent())
970 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
971 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
972 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
973 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
974 data_shndx
, reloc
.get_r_offset());
977 gold_assert(lsym
.get_st_value() == 0);
978 unsigned int shndx
= lsym
.get_st_shndx();
980 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
983 object
->error(_("section symbol %u has bad shndx %u"),
986 rel_dyn
->add_local_section(object
, shndx
,
987 r_type
, output_section
,
988 data_shndx
, reloc
.get_r_offset());
993 case elfcpp::R_386_PC32
:
994 case elfcpp::R_386_PC16
:
995 case elfcpp::R_386_PC8
:
998 case elfcpp::R_386_PLT32
:
999 // Since we know this is a local symbol, we can handle this as a
1003 case elfcpp::R_386_GOTOFF
:
1004 case elfcpp::R_386_GOTPC
:
1005 // We need a GOT section.
1006 target
->got_section(symtab
, layout
);
1009 case elfcpp::R_386_GOT32
:
1011 // The symbol requires a GOT entry.
1012 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1013 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1014 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
1016 // If we are generating a shared object, we need to add a
1017 // dynamic RELATIVE relocation for this symbol's GOT entry.
1018 if (parameters
->options().output_is_position_independent())
1020 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1021 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1022 rel_dyn
->add_local_relative(
1023 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
1024 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1030 // These are relocations which should only be seen by the
1031 // dynamic linker, and should never be seen here.
1032 case elfcpp::R_386_COPY
:
1033 case elfcpp::R_386_GLOB_DAT
:
1034 case elfcpp::R_386_JUMP_SLOT
:
1035 case elfcpp::R_386_RELATIVE
:
1036 case elfcpp::R_386_TLS_TPOFF
:
1037 case elfcpp::R_386_TLS_DTPMOD32
:
1038 case elfcpp::R_386_TLS_DTPOFF32
:
1039 case elfcpp::R_386_TLS_TPOFF32
:
1040 case elfcpp::R_386_TLS_DESC
:
1041 gold_error(_("%s: unexpected reloc %u in object file"),
1042 object
->name().c_str(), r_type
);
1045 // These are initial TLS relocs, which are expected when
1047 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1048 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1049 case elfcpp::R_386_TLS_DESC_CALL
:
1050 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1051 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1052 case elfcpp::R_386_TLS_IE
: // Initial-exec
1053 case elfcpp::R_386_TLS_IE_32
:
1054 case elfcpp::R_386_TLS_GOTIE
:
1055 case elfcpp::R_386_TLS_LE
: // Local-exec
1056 case elfcpp::R_386_TLS_LE_32
:
1058 bool output_is_shared
= parameters
->options().shared();
1059 const tls::Tls_optimization optimized_type
1060 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1063 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1064 if (optimized_type
== tls::TLSOPT_NONE
)
1066 // Create a pair of GOT entries for the module index and
1067 // dtv-relative offset.
1068 Output_data_got
<32, false>* got
1069 = target
->got_section(symtab
, layout
);
1070 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1071 unsigned int shndx
= lsym
.get_st_shndx();
1073 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1075 object
->error(_("local symbol %u has bad shndx %u"),
1078 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1080 target
->rel_dyn_section(layout
),
1081 elfcpp::R_386_TLS_DTPMOD32
, 0);
1083 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1084 unsupported_reloc_local(object
, r_type
);
1087 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1088 target
->define_tls_base_symbol(symtab
, layout
);
1089 if (optimized_type
== tls::TLSOPT_NONE
)
1091 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1092 Output_data_got
<32, false>* got
1093 = target
->got_section(symtab
, layout
);
1094 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1095 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1097 unsigned int got_offset
= got
->add_constant(0);
1098 // The local symbol value is stored in the second
1100 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1101 // That set the GOT offset of the local symbol to
1102 // point to the second entry, but we want it to
1103 // point to the first.
1104 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1106 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1107 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1110 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1111 unsupported_reloc_local(object
, r_type
);
1114 case elfcpp::R_386_TLS_DESC_CALL
:
1117 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1118 if (optimized_type
== tls::TLSOPT_NONE
)
1120 // Create a GOT entry for the module index.
1121 target
->got_mod_index_entry(symtab
, layout
, object
);
1123 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1124 unsupported_reloc_local(object
, r_type
);
1127 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1130 case elfcpp::R_386_TLS_IE
: // Initial-exec
1131 case elfcpp::R_386_TLS_IE_32
:
1132 case elfcpp::R_386_TLS_GOTIE
:
1133 layout
->set_has_static_tls();
1134 if (optimized_type
== tls::TLSOPT_NONE
)
1136 // For the R_386_TLS_IE relocation, we need to create a
1137 // dynamic relocation when building a shared library.
1138 if (r_type
== elfcpp::R_386_TLS_IE
1139 && parameters
->options().shared())
1141 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1143 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1144 rel_dyn
->add_local_relative(object
, r_sym
,
1145 elfcpp::R_386_RELATIVE
,
1146 output_section
, data_shndx
,
1147 reloc
.get_r_offset());
1149 // Create a GOT entry for the tp-relative offset.
1150 Output_data_got
<32, false>* got
1151 = target
->got_section(symtab
, layout
);
1152 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1153 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1154 ? elfcpp::R_386_TLS_TPOFF32
1155 : elfcpp::R_386_TLS_TPOFF
);
1156 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1157 ? GOT_TYPE_TLS_OFFSET
1158 : GOT_TYPE_TLS_NOFFSET
);
1159 got
->add_local_with_rel(object
, r_sym
, got_type
,
1160 target
->rel_dyn_section(layout
),
1163 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1164 unsupported_reloc_local(object
, r_type
);
1167 case elfcpp::R_386_TLS_LE
: // Local-exec
1168 case elfcpp::R_386_TLS_LE_32
:
1169 layout
->set_has_static_tls();
1170 if (output_is_shared
)
1172 // We need to create a dynamic relocation.
1173 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1174 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1175 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1176 ? elfcpp::R_386_TLS_TPOFF32
1177 : elfcpp::R_386_TLS_TPOFF
);
1178 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1179 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1180 data_shndx
, reloc
.get_r_offset());
1190 case elfcpp::R_386_32PLT
:
1191 case elfcpp::R_386_TLS_GD_32
:
1192 case elfcpp::R_386_TLS_GD_PUSH
:
1193 case elfcpp::R_386_TLS_GD_CALL
:
1194 case elfcpp::R_386_TLS_GD_POP
:
1195 case elfcpp::R_386_TLS_LDM_32
:
1196 case elfcpp::R_386_TLS_LDM_PUSH
:
1197 case elfcpp::R_386_TLS_LDM_CALL
:
1198 case elfcpp::R_386_TLS_LDM_POP
:
1199 case elfcpp::R_386_USED_BY_INTEL_200
:
1201 unsupported_reloc_local(object
, r_type
);
1206 // Report an unsupported relocation against a global symbol.
1209 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1210 unsigned int r_type
,
1213 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1214 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1217 // Scan a relocation for a global symbol.
1220 Target_i386::Scan::global(Symbol_table
* symtab
,
1222 Target_i386
* target
,
1223 Sized_relobj
<32, false>* object
,
1224 unsigned int data_shndx
,
1225 Output_section
* output_section
,
1226 const elfcpp::Rel
<32, false>& reloc
,
1227 unsigned int r_type
,
1232 case elfcpp::R_386_NONE
:
1233 case elfcpp::R_386_GNU_VTINHERIT
:
1234 case elfcpp::R_386_GNU_VTENTRY
:
1237 case elfcpp::R_386_32
:
1238 case elfcpp::R_386_16
:
1239 case elfcpp::R_386_8
:
1241 // Make a PLT entry if necessary.
1242 if (gsym
->needs_plt_entry())
1244 target
->make_plt_entry(symtab
, layout
, gsym
);
1245 // Since this is not a PC-relative relocation, we may be
1246 // taking the address of a function. In that case we need to
1247 // set the entry in the dynamic symbol table to the address of
1249 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1250 gsym
->set_needs_dynsym_value();
1252 // Make a dynamic relocation if necessary.
1253 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1255 if (gsym
->may_need_copy_reloc())
1257 target
->copy_reloc(symtab
, layout
, object
,
1258 data_shndx
, output_section
, gsym
, reloc
);
1260 else if (r_type
== elfcpp::R_386_32
1261 && gsym
->can_use_relative_reloc(false))
1263 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1264 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1265 output_section
, object
,
1266 data_shndx
, reloc
.get_r_offset());
1270 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1271 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1272 data_shndx
, reloc
.get_r_offset());
1278 case elfcpp::R_386_PC32
:
1279 case elfcpp::R_386_PC16
:
1280 case elfcpp::R_386_PC8
:
1282 // Make a PLT entry if necessary.
1283 if (gsym
->needs_plt_entry())
1285 // These relocations are used for function calls only in
1286 // non-PIC code. For a 32-bit relocation in a shared library,
1287 // we'll need a text relocation anyway, so we can skip the
1288 // PLT entry and let the dynamic linker bind the call directly
1289 // to the target. For smaller relocations, we should use a
1290 // PLT entry to ensure that the call can reach.
1291 if (!parameters
->options().shared()
1292 || r_type
!= elfcpp::R_386_PC32
)
1293 target
->make_plt_entry(symtab
, layout
, gsym
);
1295 // Make a dynamic relocation if necessary.
1296 int flags
= Symbol::NON_PIC_REF
;
1297 if (gsym
->is_func())
1298 flags
|= Symbol::FUNCTION_CALL
;
1299 if (gsym
->needs_dynamic_reloc(flags
))
1301 if (gsym
->may_need_copy_reloc())
1303 target
->copy_reloc(symtab
, layout
, object
,
1304 data_shndx
, output_section
, gsym
, reloc
);
1308 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1309 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1310 data_shndx
, reloc
.get_r_offset());
1316 case elfcpp::R_386_GOT32
:
1318 // The symbol requires a GOT entry.
1319 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1320 if (gsym
->final_value_is_known())
1321 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1324 // If this symbol is not fully resolved, we need to add a
1325 // GOT entry with a dynamic relocation.
1326 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1327 if (gsym
->is_from_dynobj()
1328 || gsym
->is_undefined()
1329 || gsym
->is_preemptible())
1330 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1331 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1334 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1335 rel_dyn
->add_global_relative(
1336 gsym
, elfcpp::R_386_RELATIVE
, got
,
1337 gsym
->got_offset(GOT_TYPE_STANDARD
));
1343 case elfcpp::R_386_PLT32
:
1344 // If the symbol is fully resolved, this is just a PC32 reloc.
1345 // Otherwise we need a PLT entry.
1346 if (gsym
->final_value_is_known())
1348 // If building a shared library, we can also skip the PLT entry
1349 // if the symbol is defined in the output file and is protected
1351 if (gsym
->is_defined()
1352 && !gsym
->is_from_dynobj()
1353 && !gsym
->is_preemptible())
1355 target
->make_plt_entry(symtab
, layout
, gsym
);
1358 case elfcpp::R_386_GOTOFF
:
1359 case elfcpp::R_386_GOTPC
:
1360 // We need a GOT section.
1361 target
->got_section(symtab
, layout
);
1364 // These are relocations which should only be seen by the
1365 // dynamic linker, and should never be seen here.
1366 case elfcpp::R_386_COPY
:
1367 case elfcpp::R_386_GLOB_DAT
:
1368 case elfcpp::R_386_JUMP_SLOT
:
1369 case elfcpp::R_386_RELATIVE
:
1370 case elfcpp::R_386_TLS_TPOFF
:
1371 case elfcpp::R_386_TLS_DTPMOD32
:
1372 case elfcpp::R_386_TLS_DTPOFF32
:
1373 case elfcpp::R_386_TLS_TPOFF32
:
1374 case elfcpp::R_386_TLS_DESC
:
1375 gold_error(_("%s: unexpected reloc %u in object file"),
1376 object
->name().c_str(), r_type
);
1379 // These are initial tls relocs, which are expected when
1381 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1382 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1383 case elfcpp::R_386_TLS_DESC_CALL
:
1384 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1385 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1386 case elfcpp::R_386_TLS_IE
: // Initial-exec
1387 case elfcpp::R_386_TLS_IE_32
:
1388 case elfcpp::R_386_TLS_GOTIE
:
1389 case elfcpp::R_386_TLS_LE
: // Local-exec
1390 case elfcpp::R_386_TLS_LE_32
:
1392 const bool is_final
= gsym
->final_value_is_known();
1393 const tls::Tls_optimization optimized_type
1394 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1397 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1398 if (optimized_type
== tls::TLSOPT_NONE
)
1400 // Create a pair of GOT entries for the module index and
1401 // dtv-relative offset.
1402 Output_data_got
<32, false>* got
1403 = target
->got_section(symtab
, layout
);
1404 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1405 target
->rel_dyn_section(layout
),
1406 elfcpp::R_386_TLS_DTPMOD32
,
1407 elfcpp::R_386_TLS_DTPOFF32
);
1409 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1411 // Create a GOT entry for the tp-relative offset.
1412 Output_data_got
<32, false>* got
1413 = target
->got_section(symtab
, layout
);
1414 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1415 target
->rel_dyn_section(layout
),
1416 elfcpp::R_386_TLS_TPOFF
);
1418 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1419 unsupported_reloc_global(object
, r_type
, gsym
);
1422 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1423 target
->define_tls_base_symbol(symtab
, layout
);
1424 if (optimized_type
== tls::TLSOPT_NONE
)
1426 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1427 Output_data_got
<32, false>* got
1428 = target
->got_section(symtab
, layout
);
1429 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1430 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1431 elfcpp::R_386_TLS_DESC
, 0);
1433 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1435 // Create a GOT entry for the tp-relative offset.
1436 Output_data_got
<32, false>* got
1437 = target
->got_section(symtab
, layout
);
1438 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1439 target
->rel_dyn_section(layout
),
1440 elfcpp::R_386_TLS_TPOFF
);
1442 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1443 unsupported_reloc_global(object
, r_type
, gsym
);
1446 case elfcpp::R_386_TLS_DESC_CALL
:
1449 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1450 if (optimized_type
== tls::TLSOPT_NONE
)
1452 // Create a GOT entry for the module index.
1453 target
->got_mod_index_entry(symtab
, layout
, object
);
1455 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1456 unsupported_reloc_global(object
, r_type
, gsym
);
1459 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1462 case elfcpp::R_386_TLS_IE
: // Initial-exec
1463 case elfcpp::R_386_TLS_IE_32
:
1464 case elfcpp::R_386_TLS_GOTIE
:
1465 layout
->set_has_static_tls();
1466 if (optimized_type
== tls::TLSOPT_NONE
)
1468 // For the R_386_TLS_IE relocation, we need to create a
1469 // dynamic relocation when building a shared library.
1470 if (r_type
== elfcpp::R_386_TLS_IE
1471 && parameters
->options().shared())
1473 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1474 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1475 output_section
, object
,
1477 reloc
.get_r_offset());
1479 // Create a GOT entry for the tp-relative offset.
1480 Output_data_got
<32, false>* got
1481 = target
->got_section(symtab
, layout
);
1482 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1483 ? elfcpp::R_386_TLS_TPOFF32
1484 : elfcpp::R_386_TLS_TPOFF
);
1485 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1486 ? GOT_TYPE_TLS_OFFSET
1487 : GOT_TYPE_TLS_NOFFSET
);
1488 got
->add_global_with_rel(gsym
, got_type
,
1489 target
->rel_dyn_section(layout
),
1492 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1493 unsupported_reloc_global(object
, r_type
, gsym
);
1496 case elfcpp::R_386_TLS_LE
: // Local-exec
1497 case elfcpp::R_386_TLS_LE_32
:
1498 layout
->set_has_static_tls();
1499 if (parameters
->options().shared())
1501 // We need to create a dynamic relocation.
1502 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1503 ? elfcpp::R_386_TLS_TPOFF32
1504 : elfcpp::R_386_TLS_TPOFF
);
1505 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1506 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1507 data_shndx
, reloc
.get_r_offset());
1517 case elfcpp::R_386_32PLT
:
1518 case elfcpp::R_386_TLS_GD_32
:
1519 case elfcpp::R_386_TLS_GD_PUSH
:
1520 case elfcpp::R_386_TLS_GD_CALL
:
1521 case elfcpp::R_386_TLS_GD_POP
:
1522 case elfcpp::R_386_TLS_LDM_32
:
1523 case elfcpp::R_386_TLS_LDM_PUSH
:
1524 case elfcpp::R_386_TLS_LDM_CALL
:
1525 case elfcpp::R_386_TLS_LDM_POP
:
1526 case elfcpp::R_386_USED_BY_INTEL_200
:
1528 unsupported_reloc_global(object
, r_type
, gsym
);
1533 // Process relocations for gc.
1536 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
1538 Sized_relobj
<32, false>* object
,
1539 unsigned int data_shndx
,
1541 const unsigned char* prelocs
,
1543 Output_section
* output_section
,
1544 bool needs_special_offset_handling
,
1545 size_t local_symbol_count
,
1546 const unsigned char* plocal_symbols
)
1548 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1558 needs_special_offset_handling
,
1563 // Scan relocations for a section.
1566 Target_i386::scan_relocs(Symbol_table
* symtab
,
1568 Sized_relobj
<32, false>* object
,
1569 unsigned int data_shndx
,
1570 unsigned int sh_type
,
1571 const unsigned char* prelocs
,
1573 Output_section
* output_section
,
1574 bool needs_special_offset_handling
,
1575 size_t local_symbol_count
,
1576 const unsigned char* plocal_symbols
)
1578 if (sh_type
== elfcpp::SHT_RELA
)
1580 gold_error(_("%s: unsupported RELA reloc section"),
1581 object
->name().c_str());
1585 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1595 needs_special_offset_handling
,
1600 // Finalize the sections.
1603 Target_i386::do_finalize_sections(
1605 const Input_objects
*,
1606 Symbol_table
* symtab
)
1608 const Reloc_section
* rel_plt
= (this->plt_
== NULL
1610 : this->plt_
->rel_plt());
1611 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
1612 this->rel_dyn_
, true);
1614 // Emit any relocs we saved in an attempt to avoid generating COPY
1616 if (this->copy_relocs_
.any_saved_relocs())
1617 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1619 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1620 // the .got.plt section.
1621 Symbol
* sym
= this->global_offset_table_
;
1624 uint32_t data_size
= this->got_plt_
->current_data_size();
1625 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
1629 // Return whether a direct absolute static relocation needs to be applied.
1630 // In cases where Scan::local() or Scan::global() has created
1631 // a dynamic relocation other than R_386_RELATIVE, the addend
1632 // of the relocation is carried in the data, and we must not
1633 // apply the static relocation.
1636 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1639 Output_section
* output_section
)
1641 // If the output section is not allocated, then we didn't call
1642 // scan_relocs, we didn't create a dynamic reloc, and we must apply
1644 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
1647 // For local symbols, we will have created a non-RELATIVE dynamic
1648 // relocation only if (a) the output is position independent,
1649 // (b) the relocation is absolute (not pc- or segment-relative), and
1650 // (c) the relocation is not 32 bits wide.
1652 return !(parameters
->options().output_is_position_independent()
1653 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1656 // For global symbols, we use the same helper routines used in the
1657 // scan pass. If we did not create a dynamic relocation, or if we
1658 // created a RELATIVE dynamic relocation, we should apply the static
1660 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1661 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1662 && gsym
->can_use_relative_reloc(ref_flags
1663 & Symbol::FUNCTION_CALL
);
1664 return !has_dyn
|| is_rel
;
1667 // Perform a relocation.
1670 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1671 Target_i386
* target
,
1672 Output_section
*output_section
,
1674 const elfcpp::Rel
<32, false>& rel
,
1675 unsigned int r_type
,
1676 const Sized_symbol
<32>* gsym
,
1677 const Symbol_value
<32>* psymval
,
1678 unsigned char* view
,
1679 elfcpp::Elf_types
<32>::Elf_Addr address
,
1680 section_size_type view_size
)
1682 if (this->skip_call_tls_get_addr_
)
1684 if ((r_type
!= elfcpp::R_386_PLT32
1685 && r_type
!= elfcpp::R_386_PC32
)
1687 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1688 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1689 _("missing expected TLS relocation"));
1692 this->skip_call_tls_get_addr_
= false;
1697 // Pick the value to use for symbols defined in shared objects.
1698 Symbol_value
<32> symval
;
1700 && gsym
->use_plt_offset(r_type
== elfcpp::R_386_PC8
1701 || r_type
== elfcpp::R_386_PC16
1702 || r_type
== elfcpp::R_386_PC32
))
1704 symval
.set_output_value(target
->plt_section()->address()
1705 + gsym
->plt_offset());
1709 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1711 // Get the GOT offset if needed.
1712 // The GOT pointer points to the end of the GOT section.
1713 // We need to subtract the size of the GOT section to get
1714 // the actual offset to use in the relocation.
1715 bool have_got_offset
= false;
1716 unsigned int got_offset
= 0;
1719 case elfcpp::R_386_GOT32
:
1722 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1723 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1724 - target
->got_size());
1728 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1729 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1730 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1731 - target
->got_size());
1733 have_got_offset
= true;
1742 case elfcpp::R_386_NONE
:
1743 case elfcpp::R_386_GNU_VTINHERIT
:
1744 case elfcpp::R_386_GNU_VTENTRY
:
1747 case elfcpp::R_386_32
:
1748 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
1750 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1753 case elfcpp::R_386_PC32
:
1755 int ref_flags
= Symbol::NON_PIC_REF
;
1756 if (gsym
!= NULL
&& gsym
->is_func())
1757 ref_flags
|= Symbol::FUNCTION_CALL
;
1758 if (should_apply_static_reloc(gsym
, ref_flags
, true, output_section
))
1759 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1763 case elfcpp::R_386_16
:
1764 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
1766 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1769 case elfcpp::R_386_PC16
:
1771 int ref_flags
= Symbol::NON_PIC_REF
;
1772 if (gsym
!= NULL
&& gsym
->is_func())
1773 ref_flags
|= Symbol::FUNCTION_CALL
;
1774 if (should_apply_static_reloc(gsym
, ref_flags
, false, output_section
))
1775 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1779 case elfcpp::R_386_8
:
1780 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
1782 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1785 case elfcpp::R_386_PC8
:
1787 int ref_flags
= Symbol::NON_PIC_REF
;
1788 if (gsym
!= NULL
&& gsym
->is_func())
1789 ref_flags
|= Symbol::FUNCTION_CALL
;
1790 if (should_apply_static_reloc(gsym
, ref_flags
, false,
1792 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1796 case elfcpp::R_386_PLT32
:
1797 gold_assert(gsym
== NULL
1798 || gsym
->has_plt_offset()
1799 || gsym
->final_value_is_known()
1800 || (gsym
->is_defined()
1801 && !gsym
->is_from_dynobj()
1802 && !gsym
->is_preemptible()));
1803 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1806 case elfcpp::R_386_GOT32
:
1807 gold_assert(have_got_offset
);
1808 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1811 case elfcpp::R_386_GOTOFF
:
1813 elfcpp::Elf_types
<32>::Elf_Addr value
;
1814 value
= (psymval
->value(object
, 0)
1815 - target
->got_plt_section()->address());
1816 Relocate_functions
<32, false>::rel32(view
, value
);
1820 case elfcpp::R_386_GOTPC
:
1822 elfcpp::Elf_types
<32>::Elf_Addr value
;
1823 value
= target
->got_plt_section()->address();
1824 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1828 case elfcpp::R_386_COPY
:
1829 case elfcpp::R_386_GLOB_DAT
:
1830 case elfcpp::R_386_JUMP_SLOT
:
1831 case elfcpp::R_386_RELATIVE
:
1832 // These are outstanding tls relocs, which are unexpected when
1834 case elfcpp::R_386_TLS_TPOFF
:
1835 case elfcpp::R_386_TLS_DTPMOD32
:
1836 case elfcpp::R_386_TLS_DTPOFF32
:
1837 case elfcpp::R_386_TLS_TPOFF32
:
1838 case elfcpp::R_386_TLS_DESC
:
1839 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1840 _("unexpected reloc %u in object file"),
1844 // These are initial tls relocs, which are expected when
1846 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1847 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1848 case elfcpp::R_386_TLS_DESC_CALL
:
1849 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1850 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1851 case elfcpp::R_386_TLS_IE
: // Initial-exec
1852 case elfcpp::R_386_TLS_IE_32
:
1853 case elfcpp::R_386_TLS_GOTIE
:
1854 case elfcpp::R_386_TLS_LE
: // Local-exec
1855 case elfcpp::R_386_TLS_LE_32
:
1856 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1857 view
, address
, view_size
);
1860 case elfcpp::R_386_32PLT
:
1861 case elfcpp::R_386_TLS_GD_32
:
1862 case elfcpp::R_386_TLS_GD_PUSH
:
1863 case elfcpp::R_386_TLS_GD_CALL
:
1864 case elfcpp::R_386_TLS_GD_POP
:
1865 case elfcpp::R_386_TLS_LDM_32
:
1866 case elfcpp::R_386_TLS_LDM_PUSH
:
1867 case elfcpp::R_386_TLS_LDM_CALL
:
1868 case elfcpp::R_386_TLS_LDM_POP
:
1869 case elfcpp::R_386_USED_BY_INTEL_200
:
1871 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1872 _("unsupported reloc %u"),
1880 // Perform a TLS relocation.
1883 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1884 Target_i386
* target
,
1886 const elfcpp::Rel
<32, false>& rel
,
1887 unsigned int r_type
,
1888 const Sized_symbol
<32>* gsym
,
1889 const Symbol_value
<32>* psymval
,
1890 unsigned char* view
,
1891 elfcpp::Elf_types
<32>::Elf_Addr
,
1892 section_size_type view_size
)
1894 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1896 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1898 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1900 const bool is_final
=
1902 ? !parameters
->options().output_is_position_independent()
1903 : gsym
->final_value_is_known());
1904 const tls::Tls_optimization optimized_type
1905 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1908 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1909 if (optimized_type
== tls::TLSOPT_TO_LE
)
1911 gold_assert(tls_segment
!= NULL
);
1912 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1913 rel
, r_type
, value
, view
,
1919 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1920 ? GOT_TYPE_TLS_NOFFSET
1921 : GOT_TYPE_TLS_PAIR
);
1922 unsigned int got_offset
;
1925 gold_assert(gsym
->has_got_offset(got_type
));
1926 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1930 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1931 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1932 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1933 - target
->got_size());
1935 if (optimized_type
== tls::TLSOPT_TO_IE
)
1937 gold_assert(tls_segment
!= NULL
);
1938 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1939 got_offset
, view
, view_size
);
1942 else if (optimized_type
== tls::TLSOPT_NONE
)
1944 // Relocate the field with the offset of the pair of GOT
1946 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1950 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1951 _("unsupported reloc %u"),
1955 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1956 case elfcpp::R_386_TLS_DESC_CALL
:
1957 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1958 if (optimized_type
== tls::TLSOPT_TO_LE
)
1960 gold_assert(tls_segment
!= NULL
);
1961 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
1962 rel
, r_type
, value
, view
,
1968 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1969 ? GOT_TYPE_TLS_NOFFSET
1970 : GOT_TYPE_TLS_DESC
);
1971 unsigned int got_offset
;
1974 gold_assert(gsym
->has_got_offset(got_type
));
1975 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1979 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1980 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1981 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1982 - target
->got_size());
1984 if (optimized_type
== tls::TLSOPT_TO_IE
)
1986 gold_assert(tls_segment
!= NULL
);
1987 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1988 got_offset
, view
, view_size
);
1991 else if (optimized_type
== tls::TLSOPT_NONE
)
1993 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
1995 // Relocate the field with the offset of the pair of GOT
1997 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2002 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2003 _("unsupported reloc %u"),
2007 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2008 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2010 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2011 _("both SUN and GNU model "
2012 "TLS relocations"));
2015 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2016 if (optimized_type
== tls::TLSOPT_TO_LE
)
2018 gold_assert(tls_segment
!= NULL
);
2019 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2020 value
, view
, view_size
);
2023 else if (optimized_type
== tls::TLSOPT_NONE
)
2025 // Relocate the field with the offset of the GOT entry for
2026 // the module index.
2027 unsigned int got_offset
;
2028 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2029 - target
->got_size());
2030 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2033 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2034 _("unsupported reloc %u"),
2038 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2039 if (optimized_type
== tls::TLSOPT_TO_LE
)
2041 // This reloc can appear in debugging sections, in which
2042 // case we must not convert to local-exec. We decide what
2043 // to do based on whether the section is marked as
2044 // containing executable code. That is what the GNU linker
2046 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
2047 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
2049 gold_assert(tls_segment
!= NULL
);
2050 value
-= tls_segment
->memsz();
2053 Relocate_functions
<32, false>::rel32(view
, value
);
2056 case elfcpp::R_386_TLS_IE
: // Initial-exec
2057 case elfcpp::R_386_TLS_GOTIE
:
2058 case elfcpp::R_386_TLS_IE_32
:
2059 if (optimized_type
== tls::TLSOPT_TO_LE
)
2061 gold_assert(tls_segment
!= NULL
);
2062 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2063 rel
, r_type
, value
, view
,
2067 else if (optimized_type
== tls::TLSOPT_NONE
)
2069 // Relocate the field with the offset of the GOT entry for
2070 // the tp-relative offset of the symbol.
2071 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2072 ? GOT_TYPE_TLS_OFFSET
2073 : GOT_TYPE_TLS_NOFFSET
);
2074 unsigned int got_offset
;
2077 gold_assert(gsym
->has_got_offset(got_type
));
2078 got_offset
= gsym
->got_offset(got_type
);
2082 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2083 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2084 got_offset
= object
->local_got_offset(r_sym
, got_type
);
2086 // For the R_386_TLS_IE relocation, we need to apply the
2087 // absolute address of the GOT entry.
2088 if (r_type
== elfcpp::R_386_TLS_IE
)
2089 got_offset
+= target
->got_plt_section()->address();
2090 // All GOT offsets are relative to the end of the GOT.
2091 got_offset
-= target
->got_size();
2092 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2095 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2096 _("unsupported reloc %u"),
2100 case elfcpp::R_386_TLS_LE
: // Local-exec
2101 // If we're creating a shared library, a dynamic relocation will
2102 // have been created for this location, so do not apply it now.
2103 if (!parameters
->options().shared())
2105 gold_assert(tls_segment
!= NULL
);
2106 value
-= tls_segment
->memsz();
2107 Relocate_functions
<32, false>::rel32(view
, value
);
2111 case elfcpp::R_386_TLS_LE_32
:
2112 // If we're creating a shared library, a dynamic relocation will
2113 // have been created for this location, so do not apply it now.
2114 if (!parameters
->options().shared())
2116 gold_assert(tls_segment
!= NULL
);
2117 value
= tls_segment
->memsz() - value
;
2118 Relocate_functions
<32, false>::rel32(view
, value
);
2124 // Do a relocation in which we convert a TLS General-Dynamic to a
2128 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2130 Output_segment
* tls_segment
,
2131 const elfcpp::Rel
<32, false>& rel
,
2133 elfcpp::Elf_types
<32>::Elf_Addr value
,
2134 unsigned char* view
,
2135 section_size_type view_size
)
2137 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2138 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2139 // leal foo(%reg),%eax; call ___tls_get_addr
2140 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2142 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2143 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2145 unsigned char op1
= view
[-1];
2146 unsigned char op2
= view
[-2];
2148 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2149 op2
== 0x8d || op2
== 0x04);
2150 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2156 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2157 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2158 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2159 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2160 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2164 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2165 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2166 if (rel
.get_r_offset() + 9 < view_size
2169 // There is a trailing nop. Use the size byte subl.
2170 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2175 // Use the five byte subl.
2176 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2180 value
= tls_segment
->memsz() - value
;
2181 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2183 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2185 this->skip_call_tls_get_addr_
= true;
2188 // Do a relocation in which we convert a TLS General-Dynamic to an
2192 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2195 const elfcpp::Rel
<32, false>& rel
,
2197 elfcpp::Elf_types
<32>::Elf_Addr value
,
2198 unsigned char* view
,
2199 section_size_type view_size
)
2201 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2202 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2204 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2205 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2207 unsigned char op1
= view
[-1];
2208 unsigned char op2
= view
[-2];
2210 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2211 op2
== 0x8d || op2
== 0x04);
2212 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2216 // FIXME: For now, support only the first (SIB) form.
2217 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2221 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2222 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2223 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2224 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2225 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2229 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2230 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2231 if (rel
.get_r_offset() + 9 < view_size
2234 // FIXME: This is not the right instruction sequence.
2235 // There is a trailing nop. Use the size byte subl.
2236 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2241 // FIXME: This is not the right instruction sequence.
2242 // Use the five byte subl.
2243 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2247 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2249 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2251 this->skip_call_tls_get_addr_
= true;
2254 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2255 // General-Dynamic to a Local-Exec.
2258 Target_i386::Relocate::tls_desc_gd_to_le(
2259 const Relocate_info
<32, false>* relinfo
,
2261 Output_segment
* tls_segment
,
2262 const elfcpp::Rel
<32, false>& rel
,
2263 unsigned int r_type
,
2264 elfcpp::Elf_types
<32>::Elf_Addr value
,
2265 unsigned char* view
,
2266 section_size_type view_size
)
2268 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2270 // leal foo@TLSDESC(%ebx), %eax
2271 // ==> leal foo@NTPOFF, %eax
2272 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2273 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2274 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2275 view
[-2] == 0x8d && view
[-1] == 0x83);
2277 value
-= tls_segment
->memsz();
2278 Relocate_functions
<32, false>::rel32(view
, value
);
2282 // call *foo@TLSCALL(%eax)
2284 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2285 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2286 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2287 view
[0] == 0xff && view
[1] == 0x10);
2293 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2294 // General-Dynamic to an Initial-Exec.
2297 Target_i386::Relocate::tls_desc_gd_to_ie(
2298 const Relocate_info
<32, false>* relinfo
,
2301 const elfcpp::Rel
<32, false>& rel
,
2302 unsigned int r_type
,
2303 elfcpp::Elf_types
<32>::Elf_Addr value
,
2304 unsigned char* view
,
2305 section_size_type view_size
)
2307 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2309 // leal foo@TLSDESC(%ebx), %eax
2310 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2311 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2312 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2313 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2314 view
[-2] == 0x8d && view
[-1] == 0x83);
2316 Relocate_functions
<32, false>::rel32(view
, value
);
2320 // call *foo@TLSCALL(%eax)
2322 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2323 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2324 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2325 view
[0] == 0xff && view
[1] == 0x10);
2331 // Do a relocation in which we convert a TLS Local-Dynamic to a
2335 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2338 const elfcpp::Rel
<32, false>& rel
,
2340 elfcpp::Elf_types
<32>::Elf_Addr
,
2341 unsigned char* view
,
2342 section_size_type view_size
)
2344 // leal foo(%reg), %eax; call ___tls_get_addr
2345 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2347 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2348 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2350 // FIXME: Does this test really always pass?
2351 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2352 view
[-2] == 0x8d && view
[-1] == 0x83);
2354 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2356 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2358 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2360 this->skip_call_tls_get_addr_
= true;
2363 // Do a relocation in which we convert a TLS Initial-Exec to a
2367 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2369 Output_segment
* tls_segment
,
2370 const elfcpp::Rel
<32, false>& rel
,
2371 unsigned int r_type
,
2372 elfcpp::Elf_types
<32>::Elf_Addr value
,
2373 unsigned char* view
,
2374 section_size_type view_size
)
2376 // We have to actually change the instructions, which means that we
2377 // need to examine the opcodes to figure out which instruction we
2379 if (r_type
== elfcpp::R_386_TLS_IE
)
2381 // movl %gs:XX,%eax ==> movl $YY,%eax
2382 // movl %gs:XX,%reg ==> movl $YY,%reg
2383 // addl %gs:XX,%reg ==> addl $YY,%reg
2384 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2385 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2387 unsigned char op1
= view
[-1];
2390 // movl XX,%eax ==> movl $YY,%eax
2395 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2397 unsigned char op2
= view
[-2];
2400 // movl XX,%reg ==> movl $YY,%reg
2401 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2402 (op1
& 0xc7) == 0x05);
2404 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2406 else if (op2
== 0x03)
2408 // addl XX,%reg ==> addl $YY,%reg
2409 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2410 (op1
& 0xc7) == 0x05);
2412 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2415 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2420 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2421 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2422 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2423 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2424 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2426 unsigned char op1
= view
[-1];
2427 unsigned char op2
= view
[-2];
2428 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2429 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2432 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2434 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2436 else if (op2
== 0x2b)
2438 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2440 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2442 else if (op2
== 0x03)
2444 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2446 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2449 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2452 value
= tls_segment
->memsz() - value
;
2453 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2456 Relocate_functions
<32, false>::rel32(view
, value
);
2459 // Relocate section data.
2462 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2463 unsigned int sh_type
,
2464 const unsigned char* prelocs
,
2466 Output_section
* output_section
,
2467 bool needs_special_offset_handling
,
2468 unsigned char* view
,
2469 elfcpp::Elf_types
<32>::Elf_Addr address
,
2470 section_size_type view_size
,
2471 const Reloc_symbol_changes
* reloc_symbol_changes
)
2473 gold_assert(sh_type
== elfcpp::SHT_REL
);
2475 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2476 Target_i386::Relocate
>(
2482 needs_special_offset_handling
,
2486 reloc_symbol_changes
);
2489 // Return the size of a relocation while scanning during a relocatable
2493 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2494 unsigned int r_type
,
2499 case elfcpp::R_386_NONE
:
2500 case elfcpp::R_386_GNU_VTINHERIT
:
2501 case elfcpp::R_386_GNU_VTENTRY
:
2502 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2503 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2504 case elfcpp::R_386_TLS_DESC_CALL
:
2505 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2506 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2507 case elfcpp::R_386_TLS_IE
: // Initial-exec
2508 case elfcpp::R_386_TLS_IE_32
:
2509 case elfcpp::R_386_TLS_GOTIE
:
2510 case elfcpp::R_386_TLS_LE
: // Local-exec
2511 case elfcpp::R_386_TLS_LE_32
:
2514 case elfcpp::R_386_32
:
2515 case elfcpp::R_386_PC32
:
2516 case elfcpp::R_386_GOT32
:
2517 case elfcpp::R_386_PLT32
:
2518 case elfcpp::R_386_GOTOFF
:
2519 case elfcpp::R_386_GOTPC
:
2522 case elfcpp::R_386_16
:
2523 case elfcpp::R_386_PC16
:
2526 case elfcpp::R_386_8
:
2527 case elfcpp::R_386_PC8
:
2530 // These are relocations which should only be seen by the
2531 // dynamic linker, and should never be seen here.
2532 case elfcpp::R_386_COPY
:
2533 case elfcpp::R_386_GLOB_DAT
:
2534 case elfcpp::R_386_JUMP_SLOT
:
2535 case elfcpp::R_386_RELATIVE
:
2536 case elfcpp::R_386_TLS_TPOFF
:
2537 case elfcpp::R_386_TLS_DTPMOD32
:
2538 case elfcpp::R_386_TLS_DTPOFF32
:
2539 case elfcpp::R_386_TLS_TPOFF32
:
2540 case elfcpp::R_386_TLS_DESC
:
2541 object
->error(_("unexpected reloc %u in object file"), r_type
);
2544 case elfcpp::R_386_32PLT
:
2545 case elfcpp::R_386_TLS_GD_32
:
2546 case elfcpp::R_386_TLS_GD_PUSH
:
2547 case elfcpp::R_386_TLS_GD_CALL
:
2548 case elfcpp::R_386_TLS_GD_POP
:
2549 case elfcpp::R_386_TLS_LDM_32
:
2550 case elfcpp::R_386_TLS_LDM_PUSH
:
2551 case elfcpp::R_386_TLS_LDM_CALL
:
2552 case elfcpp::R_386_TLS_LDM_POP
:
2553 case elfcpp::R_386_USED_BY_INTEL_200
:
2555 object
->error(_("unsupported reloc %u in object file"), r_type
);
2560 // Scan the relocs during a relocatable link.
2563 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
2565 Sized_relobj
<32, false>* object
,
2566 unsigned int data_shndx
,
2567 unsigned int sh_type
,
2568 const unsigned char* prelocs
,
2570 Output_section
* output_section
,
2571 bool needs_special_offset_handling
,
2572 size_t local_symbol_count
,
2573 const unsigned char* plocal_symbols
,
2574 Relocatable_relocs
* rr
)
2576 gold_assert(sh_type
== elfcpp::SHT_REL
);
2578 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2579 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2581 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2582 Scan_relocatable_relocs
>(
2590 needs_special_offset_handling
,
2596 // Relocate a section during a relocatable link.
2599 Target_i386::relocate_for_relocatable(
2600 const Relocate_info
<32, false>* relinfo
,
2601 unsigned int sh_type
,
2602 const unsigned char* prelocs
,
2604 Output_section
* output_section
,
2605 off_t offset_in_output_section
,
2606 const Relocatable_relocs
* rr
,
2607 unsigned char* view
,
2608 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2609 section_size_type view_size
,
2610 unsigned char* reloc_view
,
2611 section_size_type reloc_view_size
)
2613 gold_assert(sh_type
== elfcpp::SHT_REL
);
2615 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2620 offset_in_output_section
,
2629 // Return the value to use for a dynamic which requires special
2630 // treatment. This is how we support equality comparisons of function
2631 // pointers across shared library boundaries, as described in the
2632 // processor specific ABI supplement.
2635 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2637 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2638 return this->plt_section()->address() + gsym
->plt_offset();
2641 // Return a string used to fill a code section with nops to take up
2642 // the specified length.
2645 Target_i386::do_code_fill(section_size_type length
) const
2649 // Build a jmp instruction to skip over the bytes.
2650 unsigned char jmp
[5];
2652 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2653 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2654 + std::string(length
- 5, '\0'));
2657 // Nop sequences of various lengths.
2658 const char nop1
[1] = { 0x90 }; // nop
2659 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2660 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2661 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2662 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2663 0x00 }; // leal 0(%esi,1),%esi
2664 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2666 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2668 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2669 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2670 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2671 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2673 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2674 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2676 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2677 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2679 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2680 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2681 0x00, 0x00, 0x00, 0x00 };
2682 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2683 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2684 0x27, 0x00, 0x00, 0x00,
2686 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2687 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2688 0xbc, 0x27, 0x00, 0x00,
2690 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2691 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2692 0x90, 0x90, 0x90, 0x90,
2695 const char* nops
[16] = {
2697 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2698 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2701 return std::string(nops
[length
], length
);
2704 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2705 // compiled with -fstack-split. The function calls non-stack-split
2706 // code. We have to change the function so that it always ensures
2707 // that it has enough stack space to run some random function.
2710 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
2711 section_offset_type fnoffset
,
2712 section_size_type fnsize
,
2713 unsigned char* view
,
2714 section_size_type view_size
,
2716 std::string
* to
) const
2718 // The function starts with a comparison of the stack pointer and a
2719 // field in the TCB. This is followed by a jump.
2722 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
2725 // We will call __morestack if the carry flag is set after this
2726 // comparison. We turn the comparison into an stc instruction
2728 view
[fnoffset
] = '\xf9';
2729 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
2731 // lea NN(%esp),%ecx
2732 // lea NN(%esp),%edx
2733 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
2734 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
2737 // This is loading an offset from the stack pointer for a
2738 // comparison. The offset is negative, so we decrease the
2739 // offset by the amount of space we need for the stack. This
2740 // means we will avoid calling __morestack if there happens to
2741 // be plenty of space on the stack already.
2742 unsigned char* pval
= view
+ fnoffset
+ 3;
2743 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
2744 val
-= parameters
->options().split_stack_adjust_size();
2745 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
2749 if (!object
->has_no_split_stack())
2750 object
->error(_("failed to match split-stack sequence at "
2751 "section %u offset %0zx"),
2752 shndx
, static_cast<size_t>(fnoffset
));
2756 // We have to change the function so that it calls
2757 // __morestack_non_split instead of __morestack. The former will
2758 // allocate additional stack space.
2759 *from
= "__morestack";
2760 *to
= "__morestack_non_split";
2763 // The selector for i386 object files.
2765 class Target_selector_i386
: public Target_selector_freebsd
2768 Target_selector_i386()
2769 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
2770 "elf32-i386", "elf32-i386-freebsd")
2774 do_instantiate_target()
2775 { return new Target_i386(); }
2778 Target_selector_i386 target_selector_i386
;
2780 } // End anonymous namespace.