1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010 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
), got_tlsdesc_(NULL
),
63 global_offset_table_(NULL
), rel_dyn_(NULL
),
64 copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
65 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
69 can_check_for_function_pointers() const
72 // Process the relocations to determine unreferenced sections for
73 // garbage collection.
75 gc_process_relocs(Symbol_table
* symtab
,
77 Sized_relobj
<32, false>* object
,
78 unsigned int data_shndx
,
80 const unsigned char* prelocs
,
82 Output_section
* output_section
,
83 bool needs_special_offset_handling
,
84 size_t local_symbol_count
,
85 const unsigned char* plocal_symbols
);
87 // Scan the relocations to look for symbol adjustments.
89 scan_relocs(Symbol_table
* symtab
,
91 Sized_relobj
<32, false>* object
,
92 unsigned int data_shndx
,
94 const unsigned char* prelocs
,
96 Output_section
* output_section
,
97 bool needs_special_offset_handling
,
98 size_t local_symbol_count
,
99 const unsigned char* plocal_symbols
);
101 // Finalize the sections.
103 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
105 // Return the value to use for a dynamic which requires special
108 do_dynsym_value(const Symbol
*) const;
110 // Relocate a section.
112 relocate_section(const Relocate_info
<32, false>*,
113 unsigned int sh_type
,
114 const unsigned char* prelocs
,
116 Output_section
* output_section
,
117 bool needs_special_offset_handling
,
119 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
120 section_size_type view_size
,
121 const Reloc_symbol_changes
*);
123 // Scan the relocs during a relocatable link.
125 scan_relocatable_relocs(Symbol_table
* symtab
,
127 Sized_relobj
<32, false>* object
,
128 unsigned int data_shndx
,
129 unsigned int sh_type
,
130 const unsigned char* prelocs
,
132 Output_section
* output_section
,
133 bool needs_special_offset_handling
,
134 size_t local_symbol_count
,
135 const unsigned char* plocal_symbols
,
136 Relocatable_relocs
*);
138 // Relocate a section during a relocatable link.
140 relocate_for_relocatable(const Relocate_info
<32, false>*,
141 unsigned int sh_type
,
142 const unsigned char* prelocs
,
144 Output_section
* output_section
,
145 off_t offset_in_output_section
,
146 const Relocatable_relocs
*,
148 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
149 section_size_type view_size
,
150 unsigned char* reloc_view
,
151 section_size_type reloc_view_size
);
153 // Return a string used to fill a code section with nops.
155 do_code_fill(section_size_type length
) const;
157 // Return whether SYM is defined by the ABI.
159 do_is_defined_by_abi(const Symbol
* sym
) const
160 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
162 // Return whether a symbol name implies a local label. The UnixWare
163 // 2.1 cc generates temporary symbols that start with .X, so we
164 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
165 // If so, we should move the .X recognition into
166 // Target::do_is_local_label_name.
168 do_is_local_label_name(const char* name
) const
170 if (name
[0] == '.' && name
[1] == 'X')
172 return Target::do_is_local_label_name(name
);
175 // Return whether SYM is call to a non-split function.
177 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
179 // Adjust -fstack-split code which calls non-stack-split code.
181 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
182 section_offset_type fnoffset
, section_size_type fnsize
,
183 unsigned char* view
, section_size_type view_size
,
184 std::string
* from
, std::string
* to
) const;
186 // Return the size of the GOT section.
190 gold_assert(this->got_
!= NULL
);
191 return this->got_
->data_size();
194 // Return the number of entries in the GOT.
196 got_entry_count() const
198 if (this->got_
== NULL
)
200 return this->got_size() / 4;
203 // Return the number of entries in the PLT.
205 plt_entry_count() const;
207 // Return the offset of the first non-reserved PLT entry.
209 first_plt_entry_offset() const;
211 // Return the size of each PLT entry.
213 plt_entry_size() const;
216 // The class which scans relocations.
220 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
221 Sized_relobj
<32, false>* object
,
222 unsigned int data_shndx
,
223 Output_section
* output_section
,
224 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
225 const elfcpp::Sym
<32, false>& lsym
);
228 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
229 Sized_relobj
<32, false>* object
,
230 unsigned int data_shndx
,
231 Output_section
* output_section
,
232 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
236 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
238 Sized_relobj
<32, false>* object
,
239 unsigned int data_shndx
,
240 Output_section
* output_section
,
241 const elfcpp::Rel
<32, false>& reloc
,
243 const elfcpp::Sym
<32, false>& lsym
);
246 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
248 Sized_relobj
<32, false>* object
,
249 unsigned int data_shndx
,
250 Output_section
* output_section
,
251 const elfcpp::Rel
<32, false>& reloc
,
256 possible_function_pointer_reloc(unsigned int r_type
);
259 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
262 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
266 // The class which implements relocation.
271 : skip_call_tls_get_addr_(false),
272 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
277 if (this->skip_call_tls_get_addr_
)
279 // FIXME: This needs to specify the location somehow.
280 gold_error(_("missing expected TLS relocation"));
284 // Return whether the static relocation needs to be applied.
286 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
289 Output_section
* output_section
);
291 // Do a relocation. Return false if the caller should not issue
292 // any warnings about this relocation.
294 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
295 size_t relnum
, const elfcpp::Rel
<32, false>&,
296 unsigned int r_type
, const Sized_symbol
<32>*,
297 const Symbol_value
<32>*,
298 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
302 // Do a TLS relocation.
304 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
305 size_t relnum
, const elfcpp::Rel
<32, false>&,
306 unsigned int r_type
, const Sized_symbol
<32>*,
307 const Symbol_value
<32>*,
308 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
311 // Do a TLS General-Dynamic to Initial-Exec transition.
313 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
314 Output_segment
* tls_segment
,
315 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
316 elfcpp::Elf_types
<32>::Elf_Addr value
,
318 section_size_type view_size
);
320 // Do a TLS General-Dynamic to Local-Exec transition.
322 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
323 Output_segment
* tls_segment
,
324 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
325 elfcpp::Elf_types
<32>::Elf_Addr value
,
327 section_size_type view_size
);
329 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
332 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
333 Output_segment
* tls_segment
,
334 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
335 elfcpp::Elf_types
<32>::Elf_Addr value
,
337 section_size_type view_size
);
339 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
342 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
343 Output_segment
* tls_segment
,
344 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
345 elfcpp::Elf_types
<32>::Elf_Addr value
,
347 section_size_type view_size
);
349 // Do a TLS Local-Dynamic to Local-Exec transition.
351 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
352 Output_segment
* tls_segment
,
353 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
354 elfcpp::Elf_types
<32>::Elf_Addr value
,
356 section_size_type view_size
);
358 // Do a TLS Initial-Exec to Local-Exec transition.
360 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
361 Output_segment
* tls_segment
,
362 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
363 elfcpp::Elf_types
<32>::Elf_Addr value
,
365 section_size_type view_size
);
367 // We need to keep track of which type of local dynamic relocation
368 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
369 enum Local_dynamic_type
376 // This is set if we should skip the next reloc, which should be a
377 // PLT32 reloc against ___tls_get_addr.
378 bool skip_call_tls_get_addr_
;
379 // The type of local dynamic relocation we have seen in the section
380 // being relocated, if any.
381 Local_dynamic_type local_dynamic_type_
;
384 // A class which returns the size required for a relocation type,
385 // used while scanning relocs during a relocatable link.
386 class Relocatable_size_for_reloc
390 get_size_for_reloc(unsigned int, Relobj
*);
393 // Adjust TLS relocation type based on the options and whether this
394 // is a local symbol.
395 static tls::Tls_optimization
396 optimize_tls_reloc(bool is_final
, int r_type
);
398 // Get the GOT section, creating it if necessary.
399 Output_data_got
<32, false>*
400 got_section(Symbol_table
*, Layout
*);
402 // Get the GOT PLT section.
404 got_plt_section() const
406 gold_assert(this->got_plt_
!= NULL
);
407 return this->got_plt_
;
410 // Get the GOT section for TLSDESC entries.
411 Output_data_got
<32, false>*
412 got_tlsdesc_section() const
414 gold_assert(this->got_tlsdesc_
!= NULL
);
415 return this->got_tlsdesc_
;
418 // Create a PLT entry for a global symbol.
420 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
422 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
424 define_tls_base_symbol(Symbol_table
*, Layout
*);
426 // Create a GOT entry for the TLS module index.
428 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
429 Sized_relobj
<32, false>* object
);
431 // Get the PLT section.
432 Output_data_plt_i386
*
435 gold_assert(this->plt_
!= NULL
);
439 // Get the dynamic reloc section, creating it if necessary.
441 rel_dyn_section(Layout
*);
443 // Get the section to use for TLS_DESC relocations.
445 rel_tls_desc_section(Layout
*) const;
447 // Add a potential copy relocation.
449 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
450 Sized_relobj
<32, false>* object
,
451 unsigned int shndx
, Output_section
* output_section
,
452 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
454 this->copy_relocs_
.copy_reloc(symtab
, layout
,
455 symtab
->get_sized_symbol
<32>(sym
),
456 object
, shndx
, output_section
, reloc
,
457 this->rel_dyn_section(layout
));
460 // Information about this specific target which we pass to the
461 // general Target structure.
462 static const Target::Target_info i386_info
;
464 // The types of GOT entries needed for this platform.
465 // These values are exposed to the ABI in an incremental link.
466 // Do not renumber existing values without changing the version
467 // number of the .gnu_incremental_inputs section.
470 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
471 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
472 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
473 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
474 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
478 Output_data_got
<32, false>* got_
;
480 Output_data_plt_i386
* plt_
;
481 // The GOT PLT section.
482 Output_data_space
* got_plt_
;
483 // The GOT section for TLSDESC relocations.
484 Output_data_got
<32, false>* got_tlsdesc_
;
485 // The _GLOBAL_OFFSET_TABLE_ symbol.
486 Symbol
* global_offset_table_
;
487 // The dynamic reloc section.
488 Reloc_section
* rel_dyn_
;
489 // Relocs saved to avoid a COPY reloc.
490 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
491 // Space for variables copied with a COPY reloc.
492 Output_data_space
* dynbss_
;
493 // Offset of the GOT entry for the TLS module index.
494 unsigned int got_mod_index_offset_
;
495 // True if the _TLS_MODULE_BASE_ symbol has been defined.
496 bool tls_base_symbol_defined_
;
499 const Target::Target_info
Target_i386::i386_info
=
502 false, // is_big_endian
503 elfcpp::EM_386
, // machine_code
504 false, // has_make_symbol
505 false, // has_resolve
506 true, // has_code_fill
507 true, // is_default_stack_executable
509 "/usr/lib/libc.so.1", // dynamic_linker
510 0x08048000, // default_text_segment_address
511 0x1000, // abi_pagesize (overridable by -z max-page-size)
512 0x1000, // common_pagesize (overridable by -z common-page-size)
513 elfcpp::SHN_UNDEF
, // small_common_shndx
514 elfcpp::SHN_UNDEF
, // large_common_shndx
515 0, // small_common_section_flags
516 0, // large_common_section_flags
517 NULL
, // attributes_section
518 NULL
// attributes_vendor
521 // Get the GOT section, creating it if necessary.
523 Output_data_got
<32, false>*
524 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
526 if (this->got_
== NULL
)
528 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
530 this->got_
= new Output_data_got
<32, false>();
532 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
534 | elfcpp::SHF_WRITE
),
535 this->got_
, ORDER_RELRO_LAST
, true);
537 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
538 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
540 | elfcpp::SHF_WRITE
),
541 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
544 // The first three entries are reserved.
545 this->got_plt_
->set_current_data_size(3 * 4);
547 // Those bytes can go into the relro segment.
548 layout
->increase_relro(3 * 4);
550 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
551 this->global_offset_table_
=
552 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
553 Symbol_table::PREDEFINED
,
555 0, 0, elfcpp::STT_OBJECT
,
557 elfcpp::STV_HIDDEN
, 0,
560 // If there are any TLSDESC relocations, they get GOT entries in
561 // .got.plt after the jump slot entries.
562 this->got_tlsdesc_
= new Output_data_got
<32, false>();
563 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
565 | elfcpp::SHF_WRITE
),
567 ORDER_NON_RELRO_FIRST
, false);
573 // Get the dynamic reloc section, creating it if necessary.
575 Target_i386::Reloc_section
*
576 Target_i386::rel_dyn_section(Layout
* layout
)
578 if (this->rel_dyn_
== NULL
)
580 gold_assert(layout
!= NULL
);
581 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
582 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
583 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
584 ORDER_DYNAMIC_RELOCS
, false);
586 return this->rel_dyn_
;
589 // A class to handle the PLT data.
591 class Output_data_plt_i386
: public Output_section_data
594 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
596 Output_data_plt_i386(Layout
*, Output_data_space
*);
598 // Add an entry to the PLT.
600 add_entry(Symbol
* gsym
);
602 // Return the .rel.plt section data.
605 { return this->rel_
; }
607 // Return where the TLS_DESC relocations should go.
609 rel_tls_desc(Layout
*);
611 // Return the number of PLT entries.
614 { return this->count_
; }
616 // Return the offset of the first non-reserved PLT entry.
618 first_plt_entry_offset()
619 { return plt_entry_size
; }
621 // Return the size of a PLT entry.
624 { return plt_entry_size
; }
628 do_adjust_output_section(Output_section
* os
);
630 // Write to a map file.
632 do_print_to_mapfile(Mapfile
* mapfile
) const
633 { mapfile
->print_output_data(this, _("** PLT")); }
636 // The size of an entry in the PLT.
637 static const int plt_entry_size
= 16;
639 // The first entry in the PLT for an executable.
640 static unsigned char exec_first_plt_entry
[plt_entry_size
];
642 // The first entry in the PLT for a shared object.
643 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
645 // Other entries in the PLT for an executable.
646 static unsigned char exec_plt_entry
[plt_entry_size
];
648 // Other entries in the PLT for a shared object.
649 static unsigned char dyn_plt_entry
[plt_entry_size
];
651 // Set the final size.
653 set_final_data_size()
654 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
656 // Write out the PLT data.
658 do_write(Output_file
*);
660 // The reloc section.
662 // The TLS_DESC relocations, if necessary. These must follow the
663 // regular PLT relocs.
664 Reloc_section
* tls_desc_rel_
;
665 // The .got.plt section.
666 Output_data_space
* got_plt_
;
667 // The number of PLT entries.
671 // Create the PLT section. The ordinary .got section is an argument,
672 // since we need to refer to the start. We also create our own .got
673 // section just for PLT entries.
675 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
676 Output_data_space
* got_plt
)
677 : Output_section_data(4), tls_desc_rel_(NULL
), got_plt_(got_plt
), count_(0)
679 this->rel_
= new Reloc_section(false);
680 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
681 elfcpp::SHF_ALLOC
, this->rel_
,
682 ORDER_DYNAMIC_PLT_RELOCS
, false);
686 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
688 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
689 // linker, and so do we.
693 // Add an entry to the PLT.
696 Output_data_plt_i386::add_entry(Symbol
* gsym
)
698 gold_assert(!gsym
->has_plt_offset());
700 // Note that when setting the PLT offset we skip the initial
701 // reserved PLT entry.
702 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
706 section_offset_type got_offset
= this->got_plt_
->current_data_size();
708 // Every PLT entry needs a GOT entry which points back to the PLT
709 // entry (this will be changed by the dynamic linker, normally
710 // lazily when the function is called).
711 this->got_plt_
->set_current_data_size(got_offset
+ 4);
713 // Every PLT entry needs a reloc.
714 gsym
->set_needs_dynsym_entry();
715 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
718 // Note that we don't need to save the symbol. The contents of the
719 // PLT are independent of which symbols are used. The symbols only
720 // appear in the relocations.
723 // Return where the TLS_DESC relocations should go, creating it if
724 // necessary. These follow the JUMP_SLOT relocations.
726 Output_data_plt_i386::Reloc_section
*
727 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
729 if (this->tls_desc_rel_
== NULL
)
731 this->tls_desc_rel_
= new Reloc_section(false);
732 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
733 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
734 ORDER_DYNAMIC_PLT_RELOCS
, false);
735 gold_assert(this->tls_desc_rel_
->output_section() ==
736 this->rel_
->output_section());
738 return this->tls_desc_rel_
;
741 // The first entry in the PLT for an executable.
743 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
745 0xff, 0x35, // pushl contents of memory address
746 0, 0, 0, 0, // replaced with address of .got + 4
747 0xff, 0x25, // jmp indirect
748 0, 0, 0, 0, // replaced with address of .got + 8
752 // The first entry in the PLT for a shared object.
754 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
756 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
757 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
761 // Subsequent entries in the PLT for an executable.
763 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
765 0xff, 0x25, // jmp indirect
766 0, 0, 0, 0, // replaced with address of symbol in .got
767 0x68, // pushl immediate
768 0, 0, 0, 0, // replaced with offset into relocation table
769 0xe9, // jmp relative
770 0, 0, 0, 0 // replaced with offset to start of .plt
773 // Subsequent entries in the PLT for a shared object.
775 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
777 0xff, 0xa3, // jmp *offset(%ebx)
778 0, 0, 0, 0, // replaced with offset of symbol in .got
779 0x68, // pushl immediate
780 0, 0, 0, 0, // replaced with offset into relocation table
781 0xe9, // jmp relative
782 0, 0, 0, 0 // replaced with offset to start of .plt
785 // Write out the PLT. This uses the hand-coded instructions above,
786 // and adjusts them as needed. This is all specified by the i386 ELF
787 // Processor Supplement.
790 Output_data_plt_i386::do_write(Output_file
* of
)
792 const off_t offset
= this->offset();
793 const section_size_type oview_size
=
794 convert_to_section_size_type(this->data_size());
795 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
797 const off_t got_file_offset
= this->got_plt_
->offset();
798 const section_size_type got_size
=
799 convert_to_section_size_type(this->got_plt_
->data_size());
800 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
803 unsigned char* pov
= oview
;
805 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
806 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
808 if (parameters
->options().output_is_position_independent())
809 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
812 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
813 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
814 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
816 pov
+= plt_entry_size
;
818 unsigned char* got_pov
= got_view
;
820 memset(got_pov
, 0, 12);
823 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
825 unsigned int plt_offset
= plt_entry_size
;
826 unsigned int plt_rel_offset
= 0;
827 unsigned int got_offset
= 12;
828 const unsigned int count
= this->count_
;
829 for (unsigned int i
= 0;
832 pov
+= plt_entry_size
,
834 plt_offset
+= plt_entry_size
,
835 plt_rel_offset
+= rel_size
,
838 // Set and adjust the PLT entry itself.
840 if (parameters
->options().output_is_position_independent())
842 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
843 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
847 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
848 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
853 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
854 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
855 - (plt_offset
+ plt_entry_size
));
857 // Set the entry in the GOT.
858 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
861 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
862 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
864 of
->write_output_view(offset
, oview_size
, oview
);
865 of
->write_output_view(got_file_offset
, got_size
, got_view
);
868 // Create a PLT entry for a global symbol.
871 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
873 if (gsym
->has_plt_offset())
876 if (this->plt_
== NULL
)
878 // Create the GOT sections first.
879 this->got_section(symtab
, layout
);
881 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
882 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
884 | elfcpp::SHF_EXECINSTR
),
885 this->plt_
, ORDER_PLT
, false);
888 this->plt_
->add_entry(gsym
);
891 // Return the number of entries in the PLT.
894 Target_i386::plt_entry_count() const
896 if (this->plt_
== NULL
)
898 return this->plt_
->entry_count();
901 // Return the offset of the first non-reserved PLT entry.
904 Target_i386::first_plt_entry_offset() const
906 return Output_data_plt_i386::first_plt_entry_offset();
909 // Return the size of each PLT entry.
912 Target_i386::plt_entry_size() const
914 return Output_data_plt_i386::get_plt_entry_size();
917 // Get the section to use for TLS_DESC relocations.
919 Target_i386::Reloc_section
*
920 Target_i386::rel_tls_desc_section(Layout
* layout
) const
922 return this->plt_section()->rel_tls_desc(layout
);
925 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
928 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
930 if (this->tls_base_symbol_defined_
)
933 Output_segment
* tls_segment
= layout
->tls_segment();
934 if (tls_segment
!= NULL
)
936 bool is_exec
= parameters
->options().output_is_executable();
937 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
938 Symbol_table::PREDEFINED
,
942 elfcpp::STV_HIDDEN
, 0,
944 ? Symbol::SEGMENT_END
945 : Symbol::SEGMENT_START
),
948 this->tls_base_symbol_defined_
= true;
951 // Create a GOT entry for the TLS module index.
954 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
955 Sized_relobj
<32, false>* object
)
957 if (this->got_mod_index_offset_
== -1U)
959 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
960 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
961 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
962 unsigned int got_offset
= got
->add_constant(0);
963 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
965 got
->add_constant(0);
966 this->got_mod_index_offset_
= got_offset
;
968 return this->got_mod_index_offset_
;
971 // Optimize the TLS relocation type based on what we know about the
972 // symbol. IS_FINAL is true if the final address of this symbol is
973 // known at link time.
975 tls::Tls_optimization
976 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
978 // If we are generating a shared library, then we can't do anything
980 if (parameters
->options().shared())
981 return tls::TLSOPT_NONE
;
985 case elfcpp::R_386_TLS_GD
:
986 case elfcpp::R_386_TLS_GOTDESC
:
987 case elfcpp::R_386_TLS_DESC_CALL
:
988 // These are General-Dynamic which permits fully general TLS
989 // access. Since we know that we are generating an executable,
990 // we can convert this to Initial-Exec. If we also know that
991 // this is a local symbol, we can further switch to Local-Exec.
993 return tls::TLSOPT_TO_LE
;
994 return tls::TLSOPT_TO_IE
;
996 case elfcpp::R_386_TLS_LDM
:
997 // This is Local-Dynamic, which refers to a local symbol in the
998 // dynamic TLS block. Since we know that we generating an
999 // executable, we can switch to Local-Exec.
1000 return tls::TLSOPT_TO_LE
;
1002 case elfcpp::R_386_TLS_LDO_32
:
1003 // Another type of Local-Dynamic relocation.
1004 return tls::TLSOPT_TO_LE
;
1006 case elfcpp::R_386_TLS_IE
:
1007 case elfcpp::R_386_TLS_GOTIE
:
1008 case elfcpp::R_386_TLS_IE_32
:
1009 // These are Initial-Exec relocs which get the thread offset
1010 // from the GOT. If we know that we are linking against the
1011 // local symbol, we can switch to Local-Exec, which links the
1012 // thread offset into the instruction.
1014 return tls::TLSOPT_TO_LE
;
1015 return tls::TLSOPT_NONE
;
1017 case elfcpp::R_386_TLS_LE
:
1018 case elfcpp::R_386_TLS_LE_32
:
1019 // When we already have Local-Exec, there is nothing further we
1021 return tls::TLSOPT_NONE
;
1028 // Report an unsupported relocation against a local symbol.
1031 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
1032 unsigned int r_type
)
1034 gold_error(_("%s: unsupported reloc %u against local symbol"),
1035 object
->name().c_str(), r_type
);
1038 // Scan a relocation for a local symbol.
1041 Target_i386::Scan::local(Symbol_table
* symtab
,
1043 Target_i386
* target
,
1044 Sized_relobj
<32, false>* object
,
1045 unsigned int data_shndx
,
1046 Output_section
* output_section
,
1047 const elfcpp::Rel
<32, false>& reloc
,
1048 unsigned int r_type
,
1049 const elfcpp::Sym
<32, false>& lsym
)
1053 case elfcpp::R_386_NONE
:
1054 case elfcpp::R_386_GNU_VTINHERIT
:
1055 case elfcpp::R_386_GNU_VTENTRY
:
1058 case elfcpp::R_386_32
:
1059 // If building a shared library (or a position-independent
1060 // executable), we need to create a dynamic relocation for
1061 // this location. The relocation applied at link time will
1062 // apply the link-time value, so we flag the location with
1063 // an R_386_RELATIVE relocation so the dynamic loader can
1064 // relocate it easily.
1065 if (parameters
->options().output_is_position_independent())
1067 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1068 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1069 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1070 output_section
, data_shndx
,
1071 reloc
.get_r_offset());
1075 case elfcpp::R_386_16
:
1076 case elfcpp::R_386_8
:
1077 // If building a shared library (or a position-independent
1078 // executable), we need to create a dynamic relocation for
1079 // this location. Because the addend needs to remain in the
1080 // data section, we need to be careful not to apply this
1081 // relocation statically.
1082 if (parameters
->options().output_is_position_independent())
1084 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1085 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1086 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1087 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1088 data_shndx
, reloc
.get_r_offset());
1091 gold_assert(lsym
.get_st_value() == 0);
1092 unsigned int shndx
= lsym
.get_st_shndx();
1094 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1097 object
->error(_("section symbol %u has bad shndx %u"),
1100 rel_dyn
->add_local_section(object
, shndx
,
1101 r_type
, output_section
,
1102 data_shndx
, reloc
.get_r_offset());
1107 case elfcpp::R_386_PC32
:
1108 case elfcpp::R_386_PC16
:
1109 case elfcpp::R_386_PC8
:
1112 case elfcpp::R_386_PLT32
:
1113 // Since we know this is a local symbol, we can handle this as a
1117 case elfcpp::R_386_GOTOFF
:
1118 case elfcpp::R_386_GOTPC
:
1119 // We need a GOT section.
1120 target
->got_section(symtab
, layout
);
1123 case elfcpp::R_386_GOT32
:
1125 // The symbol requires a GOT entry.
1126 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1127 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1128 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
1130 // If we are generating a shared object, we need to add a
1131 // dynamic RELATIVE relocation for this symbol's GOT entry.
1132 if (parameters
->options().output_is_position_independent())
1134 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1135 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1136 rel_dyn
->add_local_relative(
1137 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
1138 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1144 // These are relocations which should only be seen by the
1145 // dynamic linker, and should never be seen here.
1146 case elfcpp::R_386_COPY
:
1147 case elfcpp::R_386_GLOB_DAT
:
1148 case elfcpp::R_386_JUMP_SLOT
:
1149 case elfcpp::R_386_RELATIVE
:
1150 case elfcpp::R_386_TLS_TPOFF
:
1151 case elfcpp::R_386_TLS_DTPMOD32
:
1152 case elfcpp::R_386_TLS_DTPOFF32
:
1153 case elfcpp::R_386_TLS_TPOFF32
:
1154 case elfcpp::R_386_TLS_DESC
:
1155 gold_error(_("%s: unexpected reloc %u in object file"),
1156 object
->name().c_str(), r_type
);
1159 // These are initial TLS relocs, which are expected when
1161 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1162 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1163 case elfcpp::R_386_TLS_DESC_CALL
:
1164 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1165 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1166 case elfcpp::R_386_TLS_IE
: // Initial-exec
1167 case elfcpp::R_386_TLS_IE_32
:
1168 case elfcpp::R_386_TLS_GOTIE
:
1169 case elfcpp::R_386_TLS_LE
: // Local-exec
1170 case elfcpp::R_386_TLS_LE_32
:
1172 bool output_is_shared
= parameters
->options().shared();
1173 const tls::Tls_optimization optimized_type
1174 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1177 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1178 if (optimized_type
== tls::TLSOPT_NONE
)
1180 // Create a pair of GOT entries for the module index and
1181 // dtv-relative offset.
1182 Output_data_got
<32, false>* got
1183 = target
->got_section(symtab
, layout
);
1184 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1185 unsigned int shndx
= lsym
.get_st_shndx();
1187 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1189 object
->error(_("local symbol %u has bad shndx %u"),
1192 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1194 target
->rel_dyn_section(layout
),
1195 elfcpp::R_386_TLS_DTPMOD32
, 0);
1197 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1198 unsupported_reloc_local(object
, r_type
);
1201 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1202 target
->define_tls_base_symbol(symtab
, layout
);
1203 if (optimized_type
== tls::TLSOPT_NONE
)
1205 // Create a double GOT entry with an R_386_TLS_DESC
1206 // reloc. The R_386_TLS_DESC reloc is resolved
1207 // lazily, so the GOT entry needs to be in an area in
1208 // .got.plt, not .got. Call got_section to make sure
1209 // the section has been created.
1210 target
->got_section(symtab
, layout
);
1211 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1212 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1213 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1215 unsigned int got_offset
= got
->add_constant(0);
1216 // The local symbol value is stored in the second
1218 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1219 // That set the GOT offset of the local symbol to
1220 // point to the second entry, but we want it to
1221 // point to the first.
1222 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1224 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1225 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1228 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1229 unsupported_reloc_local(object
, r_type
);
1232 case elfcpp::R_386_TLS_DESC_CALL
:
1235 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1236 if (optimized_type
== tls::TLSOPT_NONE
)
1238 // Create a GOT entry for the module index.
1239 target
->got_mod_index_entry(symtab
, layout
, object
);
1241 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1242 unsupported_reloc_local(object
, r_type
);
1245 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1248 case elfcpp::R_386_TLS_IE
: // Initial-exec
1249 case elfcpp::R_386_TLS_IE_32
:
1250 case elfcpp::R_386_TLS_GOTIE
:
1251 layout
->set_has_static_tls();
1252 if (optimized_type
== tls::TLSOPT_NONE
)
1254 // For the R_386_TLS_IE relocation, we need to create a
1255 // dynamic relocation when building a shared library.
1256 if (r_type
== elfcpp::R_386_TLS_IE
1257 && parameters
->options().shared())
1259 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1261 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1262 rel_dyn
->add_local_relative(object
, r_sym
,
1263 elfcpp::R_386_RELATIVE
,
1264 output_section
, data_shndx
,
1265 reloc
.get_r_offset());
1267 // Create a GOT entry for the tp-relative offset.
1268 Output_data_got
<32, false>* got
1269 = target
->got_section(symtab
, layout
);
1270 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1271 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1272 ? elfcpp::R_386_TLS_TPOFF32
1273 : elfcpp::R_386_TLS_TPOFF
);
1274 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1275 ? GOT_TYPE_TLS_OFFSET
1276 : GOT_TYPE_TLS_NOFFSET
);
1277 got
->add_local_with_rel(object
, r_sym
, got_type
,
1278 target
->rel_dyn_section(layout
),
1281 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1282 unsupported_reloc_local(object
, r_type
);
1285 case elfcpp::R_386_TLS_LE
: // Local-exec
1286 case elfcpp::R_386_TLS_LE_32
:
1287 layout
->set_has_static_tls();
1288 if (output_is_shared
)
1290 // We need to create a dynamic relocation.
1291 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1292 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1293 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1294 ? elfcpp::R_386_TLS_TPOFF32
1295 : elfcpp::R_386_TLS_TPOFF
);
1296 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1297 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1298 data_shndx
, reloc
.get_r_offset());
1308 case elfcpp::R_386_32PLT
:
1309 case elfcpp::R_386_TLS_GD_32
:
1310 case elfcpp::R_386_TLS_GD_PUSH
:
1311 case elfcpp::R_386_TLS_GD_CALL
:
1312 case elfcpp::R_386_TLS_GD_POP
:
1313 case elfcpp::R_386_TLS_LDM_32
:
1314 case elfcpp::R_386_TLS_LDM_PUSH
:
1315 case elfcpp::R_386_TLS_LDM_CALL
:
1316 case elfcpp::R_386_TLS_LDM_POP
:
1317 case elfcpp::R_386_USED_BY_INTEL_200
:
1319 unsupported_reloc_local(object
, r_type
);
1324 // Report an unsupported relocation against a global symbol.
1327 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1328 unsigned int r_type
,
1331 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1332 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1336 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1340 case elfcpp::R_386_32
:
1341 case elfcpp::R_386_16
:
1342 case elfcpp::R_386_8
:
1343 case elfcpp::R_386_GOTOFF
:
1344 case elfcpp::R_386_GOT32
:
1355 Target_i386::Scan::local_reloc_may_be_function_pointer(
1359 Sized_relobj
<32, false>* ,
1362 const elfcpp::Rel
<32, false>& ,
1363 unsigned int r_type
,
1364 const elfcpp::Sym
<32, false>&)
1366 return possible_function_pointer_reloc(r_type
);
1370 Target_i386::Scan::global_reloc_may_be_function_pointer(
1374 Sized_relobj
<32, false>* ,
1377 const elfcpp::Rel
<32, false>& ,
1378 unsigned int r_type
,
1381 return possible_function_pointer_reloc(r_type
);
1384 // Scan a relocation for a global symbol.
1387 Target_i386::Scan::global(Symbol_table
* symtab
,
1389 Target_i386
* target
,
1390 Sized_relobj
<32, false>* object
,
1391 unsigned int data_shndx
,
1392 Output_section
* output_section
,
1393 const elfcpp::Rel
<32, false>& reloc
,
1394 unsigned int r_type
,
1399 case elfcpp::R_386_NONE
:
1400 case elfcpp::R_386_GNU_VTINHERIT
:
1401 case elfcpp::R_386_GNU_VTENTRY
:
1404 case elfcpp::R_386_32
:
1405 case elfcpp::R_386_16
:
1406 case elfcpp::R_386_8
:
1408 // Make a PLT entry if necessary.
1409 if (gsym
->needs_plt_entry())
1411 target
->make_plt_entry(symtab
, layout
, gsym
);
1412 // Since this is not a PC-relative relocation, we may be
1413 // taking the address of a function. In that case we need to
1414 // set the entry in the dynamic symbol table to the address of
1416 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1417 gsym
->set_needs_dynsym_value();
1419 // Make a dynamic relocation if necessary.
1420 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1422 if (gsym
->may_need_copy_reloc())
1424 target
->copy_reloc(symtab
, layout
, object
,
1425 data_shndx
, output_section
, gsym
, reloc
);
1427 else if (r_type
== elfcpp::R_386_32
1428 && gsym
->can_use_relative_reloc(false))
1430 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1431 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1432 output_section
, object
,
1433 data_shndx
, reloc
.get_r_offset());
1437 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1438 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1439 data_shndx
, reloc
.get_r_offset());
1445 case elfcpp::R_386_PC32
:
1446 case elfcpp::R_386_PC16
:
1447 case elfcpp::R_386_PC8
:
1449 // Make a PLT entry if necessary.
1450 if (gsym
->needs_plt_entry())
1452 // These relocations are used for function calls only in
1453 // non-PIC code. For a 32-bit relocation in a shared library,
1454 // we'll need a text relocation anyway, so we can skip the
1455 // PLT entry and let the dynamic linker bind the call directly
1456 // to the target. For smaller relocations, we should use a
1457 // PLT entry to ensure that the call can reach.
1458 if (!parameters
->options().shared()
1459 || r_type
!= elfcpp::R_386_PC32
)
1460 target
->make_plt_entry(symtab
, layout
, gsym
);
1462 // Make a dynamic relocation if necessary.
1463 int flags
= Symbol::NON_PIC_REF
;
1464 if (gsym
->is_func())
1465 flags
|= Symbol::FUNCTION_CALL
;
1466 if (gsym
->needs_dynamic_reloc(flags
))
1468 if (gsym
->may_need_copy_reloc())
1470 target
->copy_reloc(symtab
, layout
, object
,
1471 data_shndx
, output_section
, gsym
, reloc
);
1475 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1476 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1477 data_shndx
, reloc
.get_r_offset());
1483 case elfcpp::R_386_GOT32
:
1485 // The symbol requires a GOT entry.
1486 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1487 if (gsym
->final_value_is_known())
1488 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1491 // If this symbol is not fully resolved, we need to add a
1492 // GOT entry with a dynamic relocation.
1493 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1494 if (gsym
->is_from_dynobj()
1495 || gsym
->is_undefined()
1496 || gsym
->is_preemptible())
1497 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1498 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1501 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1502 rel_dyn
->add_global_relative(
1503 gsym
, elfcpp::R_386_RELATIVE
, got
,
1504 gsym
->got_offset(GOT_TYPE_STANDARD
));
1510 case elfcpp::R_386_PLT32
:
1511 // If the symbol is fully resolved, this is just a PC32 reloc.
1512 // Otherwise we need a PLT entry.
1513 if (gsym
->final_value_is_known())
1515 // If building a shared library, we can also skip the PLT entry
1516 // if the symbol is defined in the output file and is protected
1518 if (gsym
->is_defined()
1519 && !gsym
->is_from_dynobj()
1520 && !gsym
->is_preemptible())
1522 target
->make_plt_entry(symtab
, layout
, gsym
);
1525 case elfcpp::R_386_GOTOFF
:
1526 case elfcpp::R_386_GOTPC
:
1527 // We need a GOT section.
1528 target
->got_section(symtab
, layout
);
1531 // These are relocations which should only be seen by the
1532 // dynamic linker, and should never be seen here.
1533 case elfcpp::R_386_COPY
:
1534 case elfcpp::R_386_GLOB_DAT
:
1535 case elfcpp::R_386_JUMP_SLOT
:
1536 case elfcpp::R_386_RELATIVE
:
1537 case elfcpp::R_386_TLS_TPOFF
:
1538 case elfcpp::R_386_TLS_DTPMOD32
:
1539 case elfcpp::R_386_TLS_DTPOFF32
:
1540 case elfcpp::R_386_TLS_TPOFF32
:
1541 case elfcpp::R_386_TLS_DESC
:
1542 gold_error(_("%s: unexpected reloc %u in object file"),
1543 object
->name().c_str(), r_type
);
1546 // These are initial tls relocs, which are expected when
1548 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1549 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1550 case elfcpp::R_386_TLS_DESC_CALL
:
1551 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1552 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1553 case elfcpp::R_386_TLS_IE
: // Initial-exec
1554 case elfcpp::R_386_TLS_IE_32
:
1555 case elfcpp::R_386_TLS_GOTIE
:
1556 case elfcpp::R_386_TLS_LE
: // Local-exec
1557 case elfcpp::R_386_TLS_LE_32
:
1559 const bool is_final
= gsym
->final_value_is_known();
1560 const tls::Tls_optimization optimized_type
1561 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1564 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1565 if (optimized_type
== tls::TLSOPT_NONE
)
1567 // Create a pair of GOT entries for the module index and
1568 // dtv-relative offset.
1569 Output_data_got
<32, false>* got
1570 = target
->got_section(symtab
, layout
);
1571 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1572 target
->rel_dyn_section(layout
),
1573 elfcpp::R_386_TLS_DTPMOD32
,
1574 elfcpp::R_386_TLS_DTPOFF32
);
1576 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1578 // Create a GOT entry for the tp-relative offset.
1579 Output_data_got
<32, false>* got
1580 = target
->got_section(symtab
, layout
);
1581 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1582 target
->rel_dyn_section(layout
),
1583 elfcpp::R_386_TLS_TPOFF
);
1585 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1586 unsupported_reloc_global(object
, r_type
, gsym
);
1589 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1590 target
->define_tls_base_symbol(symtab
, layout
);
1591 if (optimized_type
== tls::TLSOPT_NONE
)
1593 // Create a double GOT entry with an R_386_TLS_DESC
1594 // reloc. The R_386_TLS_DESC reloc is resolved
1595 // lazily, so the GOT entry needs to be in an area in
1596 // .got.plt, not .got. Call got_section to make sure
1597 // the section has been created.
1598 target
->got_section(symtab
, layout
);
1599 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1600 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1601 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1602 elfcpp::R_386_TLS_DESC
, 0);
1604 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1606 // Create a GOT entry for the tp-relative offset.
1607 Output_data_got
<32, false>* got
1608 = target
->got_section(symtab
, layout
);
1609 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1610 target
->rel_dyn_section(layout
),
1611 elfcpp::R_386_TLS_TPOFF
);
1613 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1614 unsupported_reloc_global(object
, r_type
, gsym
);
1617 case elfcpp::R_386_TLS_DESC_CALL
:
1620 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1621 if (optimized_type
== tls::TLSOPT_NONE
)
1623 // Create a GOT entry for the module index.
1624 target
->got_mod_index_entry(symtab
, layout
, object
);
1626 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1627 unsupported_reloc_global(object
, r_type
, gsym
);
1630 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1633 case elfcpp::R_386_TLS_IE
: // Initial-exec
1634 case elfcpp::R_386_TLS_IE_32
:
1635 case elfcpp::R_386_TLS_GOTIE
:
1636 layout
->set_has_static_tls();
1637 if (optimized_type
== tls::TLSOPT_NONE
)
1639 // For the R_386_TLS_IE relocation, we need to create a
1640 // dynamic relocation when building a shared library.
1641 if (r_type
== elfcpp::R_386_TLS_IE
1642 && parameters
->options().shared())
1644 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1645 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1646 output_section
, object
,
1648 reloc
.get_r_offset());
1650 // Create a GOT entry for the tp-relative offset.
1651 Output_data_got
<32, false>* got
1652 = target
->got_section(symtab
, layout
);
1653 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1654 ? elfcpp::R_386_TLS_TPOFF32
1655 : elfcpp::R_386_TLS_TPOFF
);
1656 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1657 ? GOT_TYPE_TLS_OFFSET
1658 : GOT_TYPE_TLS_NOFFSET
);
1659 got
->add_global_with_rel(gsym
, got_type
,
1660 target
->rel_dyn_section(layout
),
1663 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1664 unsupported_reloc_global(object
, r_type
, gsym
);
1667 case elfcpp::R_386_TLS_LE
: // Local-exec
1668 case elfcpp::R_386_TLS_LE_32
:
1669 layout
->set_has_static_tls();
1670 if (parameters
->options().shared())
1672 // We need to create a dynamic relocation.
1673 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1674 ? elfcpp::R_386_TLS_TPOFF32
1675 : elfcpp::R_386_TLS_TPOFF
);
1676 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1677 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1678 data_shndx
, reloc
.get_r_offset());
1688 case elfcpp::R_386_32PLT
:
1689 case elfcpp::R_386_TLS_GD_32
:
1690 case elfcpp::R_386_TLS_GD_PUSH
:
1691 case elfcpp::R_386_TLS_GD_CALL
:
1692 case elfcpp::R_386_TLS_GD_POP
:
1693 case elfcpp::R_386_TLS_LDM_32
:
1694 case elfcpp::R_386_TLS_LDM_PUSH
:
1695 case elfcpp::R_386_TLS_LDM_CALL
:
1696 case elfcpp::R_386_TLS_LDM_POP
:
1697 case elfcpp::R_386_USED_BY_INTEL_200
:
1699 unsupported_reloc_global(object
, r_type
, gsym
);
1704 // Process relocations for gc.
1707 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
1709 Sized_relobj
<32, false>* object
,
1710 unsigned int data_shndx
,
1712 const unsigned char* prelocs
,
1714 Output_section
* output_section
,
1715 bool needs_special_offset_handling
,
1716 size_t local_symbol_count
,
1717 const unsigned char* plocal_symbols
)
1719 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1721 Target_i386::Relocatable_size_for_reloc
>(
1730 needs_special_offset_handling
,
1735 // Scan relocations for a section.
1738 Target_i386::scan_relocs(Symbol_table
* symtab
,
1740 Sized_relobj
<32, false>* object
,
1741 unsigned int data_shndx
,
1742 unsigned int sh_type
,
1743 const unsigned char* prelocs
,
1745 Output_section
* output_section
,
1746 bool needs_special_offset_handling
,
1747 size_t local_symbol_count
,
1748 const unsigned char* plocal_symbols
)
1750 if (sh_type
== elfcpp::SHT_RELA
)
1752 gold_error(_("%s: unsupported RELA reloc section"),
1753 object
->name().c_str());
1757 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1767 needs_special_offset_handling
,
1772 // Finalize the sections.
1775 Target_i386::do_finalize_sections(
1777 const Input_objects
*,
1778 Symbol_table
* symtab
)
1780 const Reloc_section
* rel_plt
= (this->plt_
== NULL
1782 : this->plt_
->rel_plt());
1783 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
1784 this->rel_dyn_
, true, false);
1786 // Emit any relocs we saved in an attempt to avoid generating COPY
1788 if (this->copy_relocs_
.any_saved_relocs())
1789 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1791 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1792 // the .got.plt section.
1793 Symbol
* sym
= this->global_offset_table_
;
1796 uint32_t data_size
= this->got_plt_
->current_data_size();
1797 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
1801 // Return whether a direct absolute static relocation needs to be applied.
1802 // In cases where Scan::local() or Scan::global() has created
1803 // a dynamic relocation other than R_386_RELATIVE, the addend
1804 // of the relocation is carried in the data, and we must not
1805 // apply the static relocation.
1808 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1811 Output_section
* output_section
)
1813 // If the output section is not allocated, then we didn't call
1814 // scan_relocs, we didn't create a dynamic reloc, and we must apply
1816 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
1819 // For local symbols, we will have created a non-RELATIVE dynamic
1820 // relocation only if (a) the output is position independent,
1821 // (b) the relocation is absolute (not pc- or segment-relative), and
1822 // (c) the relocation is not 32 bits wide.
1824 return !(parameters
->options().output_is_position_independent()
1825 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1828 // For global symbols, we use the same helper routines used in the
1829 // scan pass. If we did not create a dynamic relocation, or if we
1830 // created a RELATIVE dynamic relocation, we should apply the static
1832 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1833 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1834 && gsym
->can_use_relative_reloc(ref_flags
1835 & Symbol::FUNCTION_CALL
);
1836 return !has_dyn
|| is_rel
;
1839 // Perform a relocation.
1842 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1843 Target_i386
* target
,
1844 Output_section
*output_section
,
1846 const elfcpp::Rel
<32, false>& rel
,
1847 unsigned int r_type
,
1848 const Sized_symbol
<32>* gsym
,
1849 const Symbol_value
<32>* psymval
,
1850 unsigned char* view
,
1851 elfcpp::Elf_types
<32>::Elf_Addr address
,
1852 section_size_type view_size
)
1854 if (this->skip_call_tls_get_addr_
)
1856 if ((r_type
!= elfcpp::R_386_PLT32
1857 && r_type
!= elfcpp::R_386_PC32
)
1859 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1860 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1861 _("missing expected TLS relocation"));
1864 this->skip_call_tls_get_addr_
= false;
1869 // Pick the value to use for symbols defined in shared objects.
1870 Symbol_value
<32> symval
;
1872 && gsym
->use_plt_offset(r_type
== elfcpp::R_386_PC8
1873 || r_type
== elfcpp::R_386_PC16
1874 || r_type
== elfcpp::R_386_PC32
))
1876 symval
.set_output_value(target
->plt_section()->address()
1877 + gsym
->plt_offset());
1881 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1883 // Get the GOT offset if needed.
1884 // The GOT pointer points to the end of the GOT section.
1885 // We need to subtract the size of the GOT section to get
1886 // the actual offset to use in the relocation.
1887 bool have_got_offset
= false;
1888 unsigned int got_offset
= 0;
1891 case elfcpp::R_386_GOT32
:
1894 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1895 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1896 - target
->got_size());
1900 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1901 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1902 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1903 - target
->got_size());
1905 have_got_offset
= true;
1914 case elfcpp::R_386_NONE
:
1915 case elfcpp::R_386_GNU_VTINHERIT
:
1916 case elfcpp::R_386_GNU_VTENTRY
:
1919 case elfcpp::R_386_32
:
1920 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
1922 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1925 case elfcpp::R_386_PC32
:
1927 int ref_flags
= Symbol::NON_PIC_REF
;
1928 if (gsym
!= NULL
&& gsym
->is_func())
1929 ref_flags
|= Symbol::FUNCTION_CALL
;
1930 if (should_apply_static_reloc(gsym
, ref_flags
, true, output_section
))
1931 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1935 case elfcpp::R_386_16
:
1936 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
1938 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1941 case elfcpp::R_386_PC16
:
1943 int ref_flags
= Symbol::NON_PIC_REF
;
1944 if (gsym
!= NULL
&& gsym
->is_func())
1945 ref_flags
|= Symbol::FUNCTION_CALL
;
1946 if (should_apply_static_reloc(gsym
, ref_flags
, false, output_section
))
1947 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1951 case elfcpp::R_386_8
:
1952 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
1954 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1957 case elfcpp::R_386_PC8
:
1959 int ref_flags
= Symbol::NON_PIC_REF
;
1960 if (gsym
!= NULL
&& gsym
->is_func())
1961 ref_flags
|= Symbol::FUNCTION_CALL
;
1962 if (should_apply_static_reloc(gsym
, ref_flags
, false,
1964 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1968 case elfcpp::R_386_PLT32
:
1969 gold_assert(gsym
== NULL
1970 || gsym
->has_plt_offset()
1971 || gsym
->final_value_is_known()
1972 || (gsym
->is_defined()
1973 && !gsym
->is_from_dynobj()
1974 && !gsym
->is_preemptible()));
1975 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1978 case elfcpp::R_386_GOT32
:
1979 gold_assert(have_got_offset
);
1980 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1983 case elfcpp::R_386_GOTOFF
:
1985 elfcpp::Elf_types
<32>::Elf_Addr value
;
1986 value
= (psymval
->value(object
, 0)
1987 - target
->got_plt_section()->address());
1988 Relocate_functions
<32, false>::rel32(view
, value
);
1992 case elfcpp::R_386_GOTPC
:
1994 elfcpp::Elf_types
<32>::Elf_Addr value
;
1995 value
= target
->got_plt_section()->address();
1996 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2000 case elfcpp::R_386_COPY
:
2001 case elfcpp::R_386_GLOB_DAT
:
2002 case elfcpp::R_386_JUMP_SLOT
:
2003 case elfcpp::R_386_RELATIVE
:
2004 // These are outstanding tls relocs, which are unexpected when
2006 case elfcpp::R_386_TLS_TPOFF
:
2007 case elfcpp::R_386_TLS_DTPMOD32
:
2008 case elfcpp::R_386_TLS_DTPOFF32
:
2009 case elfcpp::R_386_TLS_TPOFF32
:
2010 case elfcpp::R_386_TLS_DESC
:
2011 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2012 _("unexpected reloc %u in object file"),
2016 // These are initial tls relocs, which are expected when
2018 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2019 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2020 case elfcpp::R_386_TLS_DESC_CALL
:
2021 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2022 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2023 case elfcpp::R_386_TLS_IE
: // Initial-exec
2024 case elfcpp::R_386_TLS_IE_32
:
2025 case elfcpp::R_386_TLS_GOTIE
:
2026 case elfcpp::R_386_TLS_LE
: // Local-exec
2027 case elfcpp::R_386_TLS_LE_32
:
2028 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2029 view
, address
, view_size
);
2032 case elfcpp::R_386_32PLT
:
2033 case elfcpp::R_386_TLS_GD_32
:
2034 case elfcpp::R_386_TLS_GD_PUSH
:
2035 case elfcpp::R_386_TLS_GD_CALL
:
2036 case elfcpp::R_386_TLS_GD_POP
:
2037 case elfcpp::R_386_TLS_LDM_32
:
2038 case elfcpp::R_386_TLS_LDM_PUSH
:
2039 case elfcpp::R_386_TLS_LDM_CALL
:
2040 case elfcpp::R_386_TLS_LDM_POP
:
2041 case elfcpp::R_386_USED_BY_INTEL_200
:
2043 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2044 _("unsupported reloc %u"),
2052 // Perform a TLS relocation.
2055 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2056 Target_i386
* target
,
2058 const elfcpp::Rel
<32, false>& rel
,
2059 unsigned int r_type
,
2060 const Sized_symbol
<32>* gsym
,
2061 const Symbol_value
<32>* psymval
,
2062 unsigned char* view
,
2063 elfcpp::Elf_types
<32>::Elf_Addr
,
2064 section_size_type view_size
)
2066 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2068 const Sized_relobj
<32, false>* object
= relinfo
->object
;
2070 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2072 const bool is_final
= (gsym
== NULL
2073 ? !parameters
->options().shared()
2074 : gsym
->final_value_is_known());
2075 const tls::Tls_optimization optimized_type
2076 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2079 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2080 if (optimized_type
== tls::TLSOPT_TO_LE
)
2082 gold_assert(tls_segment
!= NULL
);
2083 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2084 rel
, r_type
, value
, view
,
2090 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2091 ? GOT_TYPE_TLS_NOFFSET
2092 : GOT_TYPE_TLS_PAIR
);
2093 unsigned int got_offset
;
2096 gold_assert(gsym
->has_got_offset(got_type
));
2097 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2101 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2102 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2103 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2104 - target
->got_size());
2106 if (optimized_type
== tls::TLSOPT_TO_IE
)
2108 gold_assert(tls_segment
!= NULL
);
2109 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2110 got_offset
, view
, view_size
);
2113 else if (optimized_type
== tls::TLSOPT_NONE
)
2115 // Relocate the field with the offset of the pair of GOT
2117 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2121 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2122 _("unsupported reloc %u"),
2126 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2127 case elfcpp::R_386_TLS_DESC_CALL
:
2128 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2129 if (optimized_type
== tls::TLSOPT_TO_LE
)
2131 gold_assert(tls_segment
!= NULL
);
2132 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2133 rel
, r_type
, value
, view
,
2139 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2140 ? GOT_TYPE_TLS_NOFFSET
2141 : GOT_TYPE_TLS_DESC
);
2142 unsigned int got_offset
= 0;
2143 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2144 && optimized_type
== tls::TLSOPT_NONE
)
2146 // We created GOT entries in the .got.tlsdesc portion of
2147 // the .got.plt section, but the offset stored in the
2148 // symbol is the offset within .got.tlsdesc.
2149 got_offset
= (target
->got_size()
2150 + target
->got_plt_section()->data_size());
2154 gold_assert(gsym
->has_got_offset(got_type
));
2155 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2159 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2160 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2161 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2162 - target
->got_size());
2164 if (optimized_type
== tls::TLSOPT_TO_IE
)
2166 gold_assert(tls_segment
!= NULL
);
2167 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2168 got_offset
, view
, view_size
);
2171 else if (optimized_type
== tls::TLSOPT_NONE
)
2173 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2175 // Relocate the field with the offset of the pair of GOT
2177 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2182 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2183 _("unsupported reloc %u"),
2187 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2188 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2190 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2191 _("both SUN and GNU model "
2192 "TLS relocations"));
2195 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2196 if (optimized_type
== tls::TLSOPT_TO_LE
)
2198 gold_assert(tls_segment
!= NULL
);
2199 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2200 value
, view
, view_size
);
2203 else if (optimized_type
== tls::TLSOPT_NONE
)
2205 // Relocate the field with the offset of the GOT entry for
2206 // the module index.
2207 unsigned int got_offset
;
2208 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2209 - target
->got_size());
2210 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2213 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2214 _("unsupported reloc %u"),
2218 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2219 if (optimized_type
== tls::TLSOPT_TO_LE
)
2221 // This reloc can appear in debugging sections, in which
2222 // case we must not convert to local-exec. We decide what
2223 // to do based on whether the section is marked as
2224 // containing executable code. That is what the GNU linker
2226 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
2227 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
2229 gold_assert(tls_segment
!= NULL
);
2230 value
-= tls_segment
->memsz();
2233 Relocate_functions
<32, false>::rel32(view
, value
);
2236 case elfcpp::R_386_TLS_IE
: // Initial-exec
2237 case elfcpp::R_386_TLS_GOTIE
:
2238 case elfcpp::R_386_TLS_IE_32
:
2239 if (optimized_type
== tls::TLSOPT_TO_LE
)
2241 gold_assert(tls_segment
!= NULL
);
2242 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2243 rel
, r_type
, value
, view
,
2247 else if (optimized_type
== tls::TLSOPT_NONE
)
2249 // Relocate the field with the offset of the GOT entry for
2250 // the tp-relative offset of the symbol.
2251 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2252 ? GOT_TYPE_TLS_OFFSET
2253 : GOT_TYPE_TLS_NOFFSET
);
2254 unsigned int got_offset
;
2257 gold_assert(gsym
->has_got_offset(got_type
));
2258 got_offset
= gsym
->got_offset(got_type
);
2262 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2263 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2264 got_offset
= object
->local_got_offset(r_sym
, got_type
);
2266 // For the R_386_TLS_IE relocation, we need to apply the
2267 // absolute address of the GOT entry.
2268 if (r_type
== elfcpp::R_386_TLS_IE
)
2269 got_offset
+= target
->got_plt_section()->address();
2270 // All GOT offsets are relative to the end of the GOT.
2271 got_offset
-= target
->got_size();
2272 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2275 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2276 _("unsupported reloc %u"),
2280 case elfcpp::R_386_TLS_LE
: // Local-exec
2281 // If we're creating a shared library, a dynamic relocation will
2282 // have been created for this location, so do not apply it now.
2283 if (!parameters
->options().shared())
2285 gold_assert(tls_segment
!= NULL
);
2286 value
-= tls_segment
->memsz();
2287 Relocate_functions
<32, false>::rel32(view
, value
);
2291 case elfcpp::R_386_TLS_LE_32
:
2292 // If we're creating a shared library, a dynamic relocation will
2293 // have been created for this location, so do not apply it now.
2294 if (!parameters
->options().shared())
2296 gold_assert(tls_segment
!= NULL
);
2297 value
= tls_segment
->memsz() - value
;
2298 Relocate_functions
<32, false>::rel32(view
, value
);
2304 // Do a relocation in which we convert a TLS General-Dynamic to a
2308 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2310 Output_segment
* tls_segment
,
2311 const elfcpp::Rel
<32, false>& rel
,
2313 elfcpp::Elf_types
<32>::Elf_Addr value
,
2314 unsigned char* view
,
2315 section_size_type view_size
)
2317 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2318 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2319 // leal foo(%reg),%eax; call ___tls_get_addr
2320 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2322 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2323 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2325 unsigned char op1
= view
[-1];
2326 unsigned char op2
= view
[-2];
2328 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2329 op2
== 0x8d || op2
== 0x04);
2330 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2336 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2337 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2338 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2339 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2340 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2344 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2345 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2346 if (rel
.get_r_offset() + 9 < view_size
2349 // There is a trailing nop. Use the size byte subl.
2350 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2355 // Use the five byte subl.
2356 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2360 value
= tls_segment
->memsz() - value
;
2361 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2363 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2365 this->skip_call_tls_get_addr_
= true;
2368 // Do a relocation in which we convert a TLS General-Dynamic to an
2372 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2375 const elfcpp::Rel
<32, false>& rel
,
2377 elfcpp::Elf_types
<32>::Elf_Addr value
,
2378 unsigned char* view
,
2379 section_size_type view_size
)
2381 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2382 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2384 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2385 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2387 unsigned char op1
= view
[-1];
2388 unsigned char op2
= view
[-2];
2390 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2391 op2
== 0x8d || op2
== 0x04);
2392 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2396 // FIXME: For now, support only the first (SIB) form.
2397 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2401 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2402 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2403 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2404 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2405 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2409 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2410 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2411 if (rel
.get_r_offset() + 9 < view_size
2414 // FIXME: This is not the right instruction sequence.
2415 // There is a trailing nop. Use the size byte subl.
2416 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2421 // FIXME: This is not the right instruction sequence.
2422 // Use the five byte subl.
2423 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2427 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2429 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2431 this->skip_call_tls_get_addr_
= true;
2434 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2435 // General-Dynamic to a Local-Exec.
2438 Target_i386::Relocate::tls_desc_gd_to_le(
2439 const Relocate_info
<32, false>* relinfo
,
2441 Output_segment
* tls_segment
,
2442 const elfcpp::Rel
<32, false>& rel
,
2443 unsigned int r_type
,
2444 elfcpp::Elf_types
<32>::Elf_Addr value
,
2445 unsigned char* view
,
2446 section_size_type view_size
)
2448 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2450 // leal foo@TLSDESC(%ebx), %eax
2451 // ==> leal foo@NTPOFF, %eax
2452 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2453 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2454 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2455 view
[-2] == 0x8d && view
[-1] == 0x83);
2457 value
-= tls_segment
->memsz();
2458 Relocate_functions
<32, false>::rel32(view
, value
);
2462 // call *foo@TLSCALL(%eax)
2464 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2465 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2466 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2467 view
[0] == 0xff && view
[1] == 0x10);
2473 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2474 // General-Dynamic to an Initial-Exec.
2477 Target_i386::Relocate::tls_desc_gd_to_ie(
2478 const Relocate_info
<32, false>* relinfo
,
2481 const elfcpp::Rel
<32, false>& rel
,
2482 unsigned int r_type
,
2483 elfcpp::Elf_types
<32>::Elf_Addr value
,
2484 unsigned char* view
,
2485 section_size_type view_size
)
2487 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2489 // leal foo@TLSDESC(%ebx), %eax
2490 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2491 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2492 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2493 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2494 view
[-2] == 0x8d && view
[-1] == 0x83);
2496 Relocate_functions
<32, false>::rel32(view
, value
);
2500 // call *foo@TLSCALL(%eax)
2502 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2503 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2504 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2505 view
[0] == 0xff && view
[1] == 0x10);
2511 // Do a relocation in which we convert a TLS Local-Dynamic to a
2515 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2518 const elfcpp::Rel
<32, false>& rel
,
2520 elfcpp::Elf_types
<32>::Elf_Addr
,
2521 unsigned char* view
,
2522 section_size_type view_size
)
2524 // leal foo(%reg), %eax; call ___tls_get_addr
2525 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2527 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2528 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2530 // FIXME: Does this test really always pass?
2531 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2532 view
[-2] == 0x8d && view
[-1] == 0x83);
2534 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2536 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2538 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2540 this->skip_call_tls_get_addr_
= true;
2543 // Do a relocation in which we convert a TLS Initial-Exec to a
2547 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2549 Output_segment
* tls_segment
,
2550 const elfcpp::Rel
<32, false>& rel
,
2551 unsigned int r_type
,
2552 elfcpp::Elf_types
<32>::Elf_Addr value
,
2553 unsigned char* view
,
2554 section_size_type view_size
)
2556 // We have to actually change the instructions, which means that we
2557 // need to examine the opcodes to figure out which instruction we
2559 if (r_type
== elfcpp::R_386_TLS_IE
)
2561 // movl %gs:XX,%eax ==> movl $YY,%eax
2562 // movl %gs:XX,%reg ==> movl $YY,%reg
2563 // addl %gs:XX,%reg ==> addl $YY,%reg
2564 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2565 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2567 unsigned char op1
= view
[-1];
2570 // movl XX,%eax ==> movl $YY,%eax
2575 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2577 unsigned char op2
= view
[-2];
2580 // movl XX,%reg ==> movl $YY,%reg
2581 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2582 (op1
& 0xc7) == 0x05);
2584 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2586 else if (op2
== 0x03)
2588 // addl XX,%reg ==> addl $YY,%reg
2589 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2590 (op1
& 0xc7) == 0x05);
2592 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2595 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2600 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2601 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2602 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2603 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2604 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2606 unsigned char op1
= view
[-1];
2607 unsigned char op2
= view
[-2];
2608 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2609 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2612 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2614 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2616 else if (op2
== 0x2b)
2618 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2620 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2622 else if (op2
== 0x03)
2624 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2626 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2629 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2632 value
= tls_segment
->memsz() - value
;
2633 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2636 Relocate_functions
<32, false>::rel32(view
, value
);
2639 // Relocate section data.
2642 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2643 unsigned int sh_type
,
2644 const unsigned char* prelocs
,
2646 Output_section
* output_section
,
2647 bool needs_special_offset_handling
,
2648 unsigned char* view
,
2649 elfcpp::Elf_types
<32>::Elf_Addr address
,
2650 section_size_type view_size
,
2651 const Reloc_symbol_changes
* reloc_symbol_changes
)
2653 gold_assert(sh_type
== elfcpp::SHT_REL
);
2655 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2656 Target_i386::Relocate
>(
2662 needs_special_offset_handling
,
2666 reloc_symbol_changes
);
2669 // Return the size of a relocation while scanning during a relocatable
2673 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2674 unsigned int r_type
,
2679 case elfcpp::R_386_NONE
:
2680 case elfcpp::R_386_GNU_VTINHERIT
:
2681 case elfcpp::R_386_GNU_VTENTRY
:
2682 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2683 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2684 case elfcpp::R_386_TLS_DESC_CALL
:
2685 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2686 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2687 case elfcpp::R_386_TLS_IE
: // Initial-exec
2688 case elfcpp::R_386_TLS_IE_32
:
2689 case elfcpp::R_386_TLS_GOTIE
:
2690 case elfcpp::R_386_TLS_LE
: // Local-exec
2691 case elfcpp::R_386_TLS_LE_32
:
2694 case elfcpp::R_386_32
:
2695 case elfcpp::R_386_PC32
:
2696 case elfcpp::R_386_GOT32
:
2697 case elfcpp::R_386_PLT32
:
2698 case elfcpp::R_386_GOTOFF
:
2699 case elfcpp::R_386_GOTPC
:
2702 case elfcpp::R_386_16
:
2703 case elfcpp::R_386_PC16
:
2706 case elfcpp::R_386_8
:
2707 case elfcpp::R_386_PC8
:
2710 // These are relocations which should only be seen by the
2711 // dynamic linker, and should never be seen here.
2712 case elfcpp::R_386_COPY
:
2713 case elfcpp::R_386_GLOB_DAT
:
2714 case elfcpp::R_386_JUMP_SLOT
:
2715 case elfcpp::R_386_RELATIVE
:
2716 case elfcpp::R_386_TLS_TPOFF
:
2717 case elfcpp::R_386_TLS_DTPMOD32
:
2718 case elfcpp::R_386_TLS_DTPOFF32
:
2719 case elfcpp::R_386_TLS_TPOFF32
:
2720 case elfcpp::R_386_TLS_DESC
:
2721 object
->error(_("unexpected reloc %u in object file"), r_type
);
2724 case elfcpp::R_386_32PLT
:
2725 case elfcpp::R_386_TLS_GD_32
:
2726 case elfcpp::R_386_TLS_GD_PUSH
:
2727 case elfcpp::R_386_TLS_GD_CALL
:
2728 case elfcpp::R_386_TLS_GD_POP
:
2729 case elfcpp::R_386_TLS_LDM_32
:
2730 case elfcpp::R_386_TLS_LDM_PUSH
:
2731 case elfcpp::R_386_TLS_LDM_CALL
:
2732 case elfcpp::R_386_TLS_LDM_POP
:
2733 case elfcpp::R_386_USED_BY_INTEL_200
:
2735 object
->error(_("unsupported reloc %u in object file"), r_type
);
2740 // Scan the relocs during a relocatable link.
2743 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
2745 Sized_relobj
<32, false>* object
,
2746 unsigned int data_shndx
,
2747 unsigned int sh_type
,
2748 const unsigned char* prelocs
,
2750 Output_section
* output_section
,
2751 bool needs_special_offset_handling
,
2752 size_t local_symbol_count
,
2753 const unsigned char* plocal_symbols
,
2754 Relocatable_relocs
* rr
)
2756 gold_assert(sh_type
== elfcpp::SHT_REL
);
2758 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2759 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2761 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2762 Scan_relocatable_relocs
>(
2770 needs_special_offset_handling
,
2776 // Relocate a section during a relocatable link.
2779 Target_i386::relocate_for_relocatable(
2780 const Relocate_info
<32, false>* relinfo
,
2781 unsigned int sh_type
,
2782 const unsigned char* prelocs
,
2784 Output_section
* output_section
,
2785 off_t offset_in_output_section
,
2786 const Relocatable_relocs
* rr
,
2787 unsigned char* view
,
2788 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2789 section_size_type view_size
,
2790 unsigned char* reloc_view
,
2791 section_size_type reloc_view_size
)
2793 gold_assert(sh_type
== elfcpp::SHT_REL
);
2795 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2800 offset_in_output_section
,
2809 // Return the value to use for a dynamic which requires special
2810 // treatment. This is how we support equality comparisons of function
2811 // pointers across shared library boundaries, as described in the
2812 // processor specific ABI supplement.
2815 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2817 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2818 return this->plt_section()->address() + gsym
->plt_offset();
2821 // Return a string used to fill a code section with nops to take up
2822 // the specified length.
2825 Target_i386::do_code_fill(section_size_type length
) const
2829 // Build a jmp instruction to skip over the bytes.
2830 unsigned char jmp
[5];
2832 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2833 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2834 + std::string(length
- 5, '\0'));
2837 // Nop sequences of various lengths.
2838 const char nop1
[1] = { 0x90 }; // nop
2839 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2840 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2841 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2842 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2843 0x00 }; // leal 0(%esi,1),%esi
2844 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2846 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2848 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2849 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2850 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2851 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2853 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2854 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2856 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2857 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2859 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2860 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2861 0x00, 0x00, 0x00, 0x00 };
2862 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2863 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2864 0x27, 0x00, 0x00, 0x00,
2866 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2867 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2868 0xbc, 0x27, 0x00, 0x00,
2870 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2871 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2872 0x90, 0x90, 0x90, 0x90,
2875 const char* nops
[16] = {
2877 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2878 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2881 return std::string(nops
[length
], length
);
2884 // Return whether SYM should be treated as a call to a non-split
2885 // function. We don't want that to be true of a call to a
2886 // get_pc_thunk function.
2889 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
2891 return (sym
->type() == elfcpp::STT_FUNC
2892 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
2895 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2896 // compiled with -fstack-split. The function calls non-stack-split
2897 // code. We have to change the function so that it always ensures
2898 // that it has enough stack space to run some random function.
2901 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
2902 section_offset_type fnoffset
,
2903 section_size_type fnsize
,
2904 unsigned char* view
,
2905 section_size_type view_size
,
2907 std::string
* to
) const
2909 // The function starts with a comparison of the stack pointer and a
2910 // field in the TCB. This is followed by a jump.
2913 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
2916 // We will call __morestack if the carry flag is set after this
2917 // comparison. We turn the comparison into an stc instruction
2919 view
[fnoffset
] = '\xf9';
2920 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
2922 // lea NN(%esp),%ecx
2923 // lea NN(%esp),%edx
2924 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
2925 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
2928 // This is loading an offset from the stack pointer for a
2929 // comparison. The offset is negative, so we decrease the
2930 // offset by the amount of space we need for the stack. This
2931 // means we will avoid calling __morestack if there happens to
2932 // be plenty of space on the stack already.
2933 unsigned char* pval
= view
+ fnoffset
+ 3;
2934 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
2935 val
-= parameters
->options().split_stack_adjust_size();
2936 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
2940 if (!object
->has_no_split_stack())
2941 object
->error(_("failed to match split-stack sequence at "
2942 "section %u offset %0zx"),
2943 shndx
, static_cast<size_t>(fnoffset
));
2947 // We have to change the function so that it calls
2948 // __morestack_non_split instead of __morestack. The former will
2949 // allocate additional stack space.
2950 *from
= "__morestack";
2951 *to
= "__morestack_non_split";
2954 // The selector for i386 object files.
2956 class Target_selector_i386
: public Target_selector_freebsd
2959 Target_selector_i386()
2960 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
2961 "elf32-i386", "elf32-i386-freebsd")
2965 do_instantiate_target()
2966 { return new Target_i386(); }
2969 Target_selector_i386 target_selector_i386
;
2971 } // End anonymous namespace.