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 // A class to handle the PLT data.
50 class Output_data_plt_i386
: public Output_section_data
53 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
55 Output_data_plt_i386(Symbol_table
*, Layout
*, Output_data_space
*);
57 // Add an entry to the PLT.
59 add_entry(Symbol
* gsym
);
61 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
63 add_local_ifunc_entry(Sized_relobj
<32, false>* relobj
,
64 unsigned int local_sym_index
);
66 // Return the .rel.plt section data.
69 { return this->rel_
; }
71 // Return where the TLS_DESC relocations should go.
73 rel_tls_desc(Layout
*);
75 // Return the number of PLT entries.
78 { return this->count_
; }
80 // Return the offset of the first non-reserved PLT entry.
82 first_plt_entry_offset()
83 { return plt_entry_size
; }
85 // Return the size of a PLT entry.
88 { return plt_entry_size
; }
92 do_adjust_output_section(Output_section
* os
);
94 // Write to a map file.
96 do_print_to_mapfile(Mapfile
* mapfile
) const
97 { mapfile
->print_output_data(this, _("** PLT")); }
100 // The size of an entry in the PLT.
101 static const int plt_entry_size
= 16;
103 // The first entry in the PLT for an executable.
104 static unsigned char exec_first_plt_entry
[plt_entry_size
];
106 // The first entry in the PLT for a shared object.
107 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
109 // Other entries in the PLT for an executable.
110 static unsigned char exec_plt_entry
[plt_entry_size
];
112 // Other entries in the PLT for a shared object.
113 static unsigned char dyn_plt_entry
[plt_entry_size
];
115 // Set the final size.
117 set_final_data_size()
118 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
120 // Write out the PLT data.
122 do_write(Output_file
*);
124 // We keep a list of global STT_GNU_IFUNC symbols, each with its
125 // offset in the GOT.
129 unsigned int got_offset
;
132 // We keep a list of local STT_GNU_IFUNC symbols, each with its
133 // offset in the GOT.
136 Sized_relobj
<32, false>* object
;
137 unsigned int local_sym_index
;
138 unsigned int got_offset
;
141 // The reloc section.
143 // The TLS_DESC relocations, if necessary. These must follow the
144 // regular PLT relocs.
145 Reloc_section
* tls_desc_rel_
;
146 // The .got.plt section.
147 Output_data_space
* got_plt_
;
148 // The number of PLT entries.
150 // Global STT_GNU_IFUNC symbols.
151 std::vector
<Global_ifunc
> global_ifuncs_
;
152 // Local STT_GNU_IFUNC symbols.
153 std::vector
<Local_ifunc
> local_ifuncs_
;
156 // The i386 target class.
157 // TLS info comes from
158 // http://people.redhat.com/drepper/tls.pdf
159 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
161 class Target_i386
: public Target_freebsd
<32, false>
164 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
167 : Target_freebsd
<32, false>(&i386_info
),
168 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_tlsdesc_(NULL
),
169 global_offset_table_(NULL
), rel_dyn_(NULL
),
170 copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
171 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
175 can_check_for_function_pointers() const
179 can_icf_inline_merge_sections () const
182 // Process the relocations to determine unreferenced sections for
183 // garbage collection.
185 gc_process_relocs(Symbol_table
* symtab
,
187 Sized_relobj
<32, false>* object
,
188 unsigned int data_shndx
,
189 unsigned int sh_type
,
190 const unsigned char* prelocs
,
192 Output_section
* output_section
,
193 bool needs_special_offset_handling
,
194 size_t local_symbol_count
,
195 const unsigned char* plocal_symbols
);
197 // Scan the relocations to look for symbol adjustments.
199 scan_relocs(Symbol_table
* symtab
,
201 Sized_relobj
<32, false>* object
,
202 unsigned int data_shndx
,
203 unsigned int sh_type
,
204 const unsigned char* prelocs
,
206 Output_section
* output_section
,
207 bool needs_special_offset_handling
,
208 size_t local_symbol_count
,
209 const unsigned char* plocal_symbols
);
211 // Finalize the sections.
213 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
215 // Return the value to use for a dynamic which requires special
218 do_dynsym_value(const Symbol
*) const;
220 // Relocate a section.
222 relocate_section(const Relocate_info
<32, false>*,
223 unsigned int sh_type
,
224 const unsigned char* prelocs
,
226 Output_section
* output_section
,
227 bool needs_special_offset_handling
,
229 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
230 section_size_type view_size
,
231 const Reloc_symbol_changes
*);
233 // Scan the relocs during a relocatable link.
235 scan_relocatable_relocs(Symbol_table
* symtab
,
237 Sized_relobj
<32, false>* object
,
238 unsigned int data_shndx
,
239 unsigned int sh_type
,
240 const unsigned char* prelocs
,
242 Output_section
* output_section
,
243 bool needs_special_offset_handling
,
244 size_t local_symbol_count
,
245 const unsigned char* plocal_symbols
,
246 Relocatable_relocs
*);
248 // Relocate a section during a relocatable link.
250 relocate_for_relocatable(const Relocate_info
<32, false>*,
251 unsigned int sh_type
,
252 const unsigned char* prelocs
,
254 Output_section
* output_section
,
255 off_t offset_in_output_section
,
256 const Relocatable_relocs
*,
258 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
259 section_size_type view_size
,
260 unsigned char* reloc_view
,
261 section_size_type reloc_view_size
);
263 // Return a string used to fill a code section with nops.
265 do_code_fill(section_size_type length
) const;
267 // Return whether SYM is defined by the ABI.
269 do_is_defined_by_abi(const Symbol
* sym
) const
270 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
272 // Return whether a symbol name implies a local label. The UnixWare
273 // 2.1 cc generates temporary symbols that start with .X, so we
274 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
275 // If so, we should move the .X recognition into
276 // Target::do_is_local_label_name.
278 do_is_local_label_name(const char* name
) const
280 if (name
[0] == '.' && name
[1] == 'X')
282 return Target::do_is_local_label_name(name
);
285 // Return the PLT section.
287 do_plt_section_for_global(const Symbol
*) const
288 { return this->plt_section(); }
291 do_plt_section_for_local(const Relobj
*, unsigned int) const
292 { return this->plt_section(); }
294 // Return whether SYM is call to a non-split function.
296 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
298 // Adjust -fsplit-stack code which calls non-split-stack code.
300 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
301 section_offset_type fnoffset
, section_size_type fnsize
,
302 unsigned char* view
, section_size_type view_size
,
303 std::string
* from
, std::string
* to
) const;
305 // Return the size of the GOT section.
309 gold_assert(this->got_
!= NULL
);
310 return this->got_
->data_size();
313 // Return the number of entries in the GOT.
315 got_entry_count() const
317 if (this->got_
== NULL
)
319 return this->got_size() / 4;
322 // Return the number of entries in the PLT.
324 plt_entry_count() const;
326 // Return the offset of the first non-reserved PLT entry.
328 first_plt_entry_offset() const;
330 // Return the size of each PLT entry.
332 plt_entry_size() const;
335 // The class which scans relocations.
340 get_reference_flags(unsigned int r_type
);
343 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
344 Sized_relobj
<32, false>* object
,
345 unsigned int data_shndx
,
346 Output_section
* output_section
,
347 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
348 const elfcpp::Sym
<32, false>& lsym
);
351 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
352 Sized_relobj
<32, false>* object
,
353 unsigned int data_shndx
,
354 Output_section
* output_section
,
355 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
359 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
361 Sized_relobj
<32, false>* object
,
362 unsigned int data_shndx
,
363 Output_section
* output_section
,
364 const elfcpp::Rel
<32, false>& reloc
,
366 const elfcpp::Sym
<32, false>& lsym
);
369 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
371 Sized_relobj
<32, false>* object
,
372 unsigned int data_shndx
,
373 Output_section
* output_section
,
374 const elfcpp::Rel
<32, false>& reloc
,
379 possible_function_pointer_reloc(unsigned int r_type
);
382 reloc_needs_plt_for_ifunc(Sized_relobj
<32, false>*, unsigned int r_type
);
385 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
388 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
392 // The class which implements relocation.
397 : skip_call_tls_get_addr_(false),
398 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
403 if (this->skip_call_tls_get_addr_
)
405 // FIXME: This needs to specify the location somehow.
406 gold_error(_("missing expected TLS relocation"));
410 // Return whether the static relocation needs to be applied.
412 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
415 Output_section
* output_section
);
417 // Do a relocation. Return false if the caller should not issue
418 // any warnings about this relocation.
420 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
421 size_t relnum
, const elfcpp::Rel
<32, false>&,
422 unsigned int r_type
, const Sized_symbol
<32>*,
423 const Symbol_value
<32>*,
424 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
428 // Do a TLS relocation.
430 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
431 size_t relnum
, const elfcpp::Rel
<32, false>&,
432 unsigned int r_type
, const Sized_symbol
<32>*,
433 const Symbol_value
<32>*,
434 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
437 // Do a TLS General-Dynamic to Initial-Exec transition.
439 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
440 Output_segment
* tls_segment
,
441 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
442 elfcpp::Elf_types
<32>::Elf_Addr value
,
444 section_size_type view_size
);
446 // Do a TLS General-Dynamic to Local-Exec transition.
448 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
449 Output_segment
* tls_segment
,
450 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
451 elfcpp::Elf_types
<32>::Elf_Addr value
,
453 section_size_type view_size
);
455 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
458 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
459 Output_segment
* tls_segment
,
460 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
461 elfcpp::Elf_types
<32>::Elf_Addr value
,
463 section_size_type view_size
);
465 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
468 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
469 Output_segment
* tls_segment
,
470 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
471 elfcpp::Elf_types
<32>::Elf_Addr value
,
473 section_size_type view_size
);
475 // Do a TLS Local-Dynamic to Local-Exec transition.
477 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
478 Output_segment
* tls_segment
,
479 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
480 elfcpp::Elf_types
<32>::Elf_Addr value
,
482 section_size_type view_size
);
484 // Do a TLS Initial-Exec to Local-Exec transition.
486 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
487 Output_segment
* tls_segment
,
488 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
489 elfcpp::Elf_types
<32>::Elf_Addr value
,
491 section_size_type view_size
);
493 // We need to keep track of which type of local dynamic relocation
494 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
495 enum Local_dynamic_type
502 // This is set if we should skip the next reloc, which should be a
503 // PLT32 reloc against ___tls_get_addr.
504 bool skip_call_tls_get_addr_
;
505 // The type of local dynamic relocation we have seen in the section
506 // being relocated, if any.
507 Local_dynamic_type local_dynamic_type_
;
510 // A class which returns the size required for a relocation type,
511 // used while scanning relocs during a relocatable link.
512 class Relocatable_size_for_reloc
516 get_size_for_reloc(unsigned int, Relobj
*);
519 // Adjust TLS relocation type based on the options and whether this
520 // is a local symbol.
521 static tls::Tls_optimization
522 optimize_tls_reloc(bool is_final
, int r_type
);
524 // Get the GOT section, creating it if necessary.
525 Output_data_got
<32, false>*
526 got_section(Symbol_table
*, Layout
*);
528 // Get the GOT PLT section.
530 got_plt_section() const
532 gold_assert(this->got_plt_
!= NULL
);
533 return this->got_plt_
;
536 // Get the GOT section for TLSDESC entries.
537 Output_data_got
<32, false>*
538 got_tlsdesc_section() const
540 gold_assert(this->got_tlsdesc_
!= NULL
);
541 return this->got_tlsdesc_
;
544 // Create the PLT section.
546 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
548 // Create a PLT entry for a global symbol.
550 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
552 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
554 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
555 Sized_relobj
<32, false>* relobj
,
556 unsigned int local_sym_index
);
558 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
560 define_tls_base_symbol(Symbol_table
*, Layout
*);
562 // Create a GOT entry for the TLS module index.
564 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
565 Sized_relobj
<32, false>* object
);
567 // Get the PLT section.
568 Output_data_plt_i386
*
571 gold_assert(this->plt_
!= NULL
);
575 // Get the dynamic reloc section, creating it if necessary.
577 rel_dyn_section(Layout
*);
579 // Get the section to use for TLS_DESC relocations.
581 rel_tls_desc_section(Layout
*) const;
583 // Add a potential copy relocation.
585 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
586 Sized_relobj
<32, false>* object
,
587 unsigned int shndx
, Output_section
* output_section
,
588 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
590 this->copy_relocs_
.copy_reloc(symtab
, layout
,
591 symtab
->get_sized_symbol
<32>(sym
),
592 object
, shndx
, output_section
, reloc
,
593 this->rel_dyn_section(layout
));
596 // Information about this specific target which we pass to the
597 // general Target structure.
598 static const Target::Target_info i386_info
;
600 // The types of GOT entries needed for this platform.
601 // These values are exposed to the ABI in an incremental link.
602 // Do not renumber existing values without changing the version
603 // number of the .gnu_incremental_inputs section.
606 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
607 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
608 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
609 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
610 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
614 Output_data_got
<32, false>* got_
;
616 Output_data_plt_i386
* plt_
;
617 // The GOT PLT section.
618 Output_data_space
* got_plt_
;
619 // The GOT section for TLSDESC relocations.
620 Output_data_got
<32, false>* got_tlsdesc_
;
621 // The _GLOBAL_OFFSET_TABLE_ symbol.
622 Symbol
* global_offset_table_
;
623 // The dynamic reloc section.
624 Reloc_section
* rel_dyn_
;
625 // Relocs saved to avoid a COPY reloc.
626 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
627 // Space for variables copied with a COPY reloc.
628 Output_data_space
* dynbss_
;
629 // Offset of the GOT entry for the TLS module index.
630 unsigned int got_mod_index_offset_
;
631 // True if the _TLS_MODULE_BASE_ symbol has been defined.
632 bool tls_base_symbol_defined_
;
635 const Target::Target_info
Target_i386::i386_info
=
638 false, // is_big_endian
639 elfcpp::EM_386
, // machine_code
640 false, // has_make_symbol
641 false, // has_resolve
642 true, // has_code_fill
643 true, // is_default_stack_executable
645 "/usr/lib/libc.so.1", // dynamic_linker
646 0x08048000, // default_text_segment_address
647 0x1000, // abi_pagesize (overridable by -z max-page-size)
648 0x1000, // common_pagesize (overridable by -z common-page-size)
649 elfcpp::SHN_UNDEF
, // small_common_shndx
650 elfcpp::SHN_UNDEF
, // large_common_shndx
651 0, // small_common_section_flags
652 0, // large_common_section_flags
653 NULL
, // attributes_section
654 NULL
// attributes_vendor
657 // Get the GOT section, creating it if necessary.
659 Output_data_got
<32, false>*
660 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
662 if (this->got_
== NULL
)
664 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
666 this->got_
= new Output_data_got
<32, false>();
668 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
670 | elfcpp::SHF_WRITE
),
671 this->got_
, ORDER_RELRO_LAST
, true);
673 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
674 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
676 | elfcpp::SHF_WRITE
),
677 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
680 // The first three entries are reserved.
681 this->got_plt_
->set_current_data_size(3 * 4);
683 // Those bytes can go into the relro segment.
684 layout
->increase_relro(3 * 4);
686 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
687 this->global_offset_table_
=
688 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
689 Symbol_table::PREDEFINED
,
691 0, 0, elfcpp::STT_OBJECT
,
693 elfcpp::STV_HIDDEN
, 0,
696 // If there are any TLSDESC relocations, they get GOT entries in
697 // .got.plt after the jump slot entries.
698 this->got_tlsdesc_
= new Output_data_got
<32, false>();
699 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
701 | elfcpp::SHF_WRITE
),
703 ORDER_NON_RELRO_FIRST
, false);
709 // Get the dynamic reloc section, creating it if necessary.
711 Target_i386::Reloc_section
*
712 Target_i386::rel_dyn_section(Layout
* layout
)
714 if (this->rel_dyn_
== NULL
)
716 gold_assert(layout
!= NULL
);
717 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
718 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
719 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
720 ORDER_DYNAMIC_RELOCS
, false);
722 return this->rel_dyn_
;
725 // Create the PLT section. The ordinary .got section is an argument,
726 // since we need to refer to the start. We also create our own .got
727 // section just for PLT entries.
729 Output_data_plt_i386::Output_data_plt_i386(Symbol_table
* symtab
,
731 Output_data_space
* got_plt
)
732 : Output_section_data(4), tls_desc_rel_(NULL
), got_plt_(got_plt
), count_(0),
733 global_ifuncs_(), local_ifuncs_()
735 this->rel_
= new Reloc_section(false);
736 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
737 elfcpp::SHF_ALLOC
, this->rel_
,
738 ORDER_DYNAMIC_PLT_RELOCS
, false);
740 if (parameters
->doing_static_link())
742 // A statically linked executable will only have a .rel.plt
743 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
744 // symbols. The library will use these symbols to locate the
745 // IRELATIVE relocs at program startup time.
746 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
747 Symbol_table::PREDEFINED
,
748 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
749 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
751 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
752 Symbol_table::PREDEFINED
,
753 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
754 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
760 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
762 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
763 // linker, and so do we.
767 // Add an entry to the PLT.
770 Output_data_plt_i386::add_entry(Symbol
* gsym
)
772 gold_assert(!gsym
->has_plt_offset());
774 // Note that when setting the PLT offset we skip the initial
775 // reserved PLT entry.
776 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
780 section_offset_type got_offset
= this->got_plt_
->current_data_size();
782 // Every PLT entry needs a GOT entry which points back to the PLT
783 // entry (this will be changed by the dynamic linker, normally
784 // lazily when the function is called).
785 this->got_plt_
->set_current_data_size(got_offset
+ 4);
787 // Every PLT entry needs a reloc.
788 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
789 && gsym
->can_use_relative_reloc(false))
791 this->rel_
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
792 this->got_plt_
, got_offset
);
793 struct Global_ifunc gi
;
795 gi
.got_offset
= got_offset
;
796 this->global_ifuncs_
.push_back(gi
);
800 gsym
->set_needs_dynsym_entry();
801 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
805 // Note that we don't need to save the symbol. The contents of the
806 // PLT are independent of which symbols are used. The symbols only
807 // appear in the relocations.
810 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
814 Output_data_plt_i386::add_local_ifunc_entry(Sized_relobj
<32, false>* relobj
,
815 unsigned int local_sym_index
)
817 unsigned int plt_offset
= (this->count_
+ 1) * plt_entry_size
;
820 section_offset_type got_offset
= this->got_plt_
->current_data_size();
822 // Every PLT entry needs a GOT entry which points back to the PLT
824 this->got_plt_
->set_current_data_size(got_offset
+ 4);
826 // Every PLT entry needs a reloc.
827 this->rel_
->add_symbolless_local_addend(relobj
, local_sym_index
,
828 elfcpp::R_386_IRELATIVE
,
829 this->got_plt_
, got_offset
);
831 struct Local_ifunc li
;
833 li
.local_sym_index
= local_sym_index
;
834 li
.got_offset
= got_offset
;
835 this->local_ifuncs_
.push_back(li
);
840 // Return where the TLS_DESC relocations should go, creating it if
841 // necessary. These follow the JUMP_SLOT relocations.
843 Output_data_plt_i386::Reloc_section
*
844 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
846 if (this->tls_desc_rel_
== NULL
)
848 this->tls_desc_rel_
= new Reloc_section(false);
849 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
850 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
851 ORDER_DYNAMIC_PLT_RELOCS
, false);
852 gold_assert(this->tls_desc_rel_
->output_section() ==
853 this->rel_
->output_section());
855 return this->tls_desc_rel_
;
858 // The first entry in the PLT for an executable.
860 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
862 0xff, 0x35, // pushl contents of memory address
863 0, 0, 0, 0, // replaced with address of .got + 4
864 0xff, 0x25, // jmp indirect
865 0, 0, 0, 0, // replaced with address of .got + 8
869 // The first entry in the PLT for a shared object.
871 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
873 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
874 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
878 // Subsequent entries in the PLT for an executable.
880 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
882 0xff, 0x25, // jmp indirect
883 0, 0, 0, 0, // replaced with address of symbol in .got
884 0x68, // pushl immediate
885 0, 0, 0, 0, // replaced with offset into relocation table
886 0xe9, // jmp relative
887 0, 0, 0, 0 // replaced with offset to start of .plt
890 // Subsequent entries in the PLT for a shared object.
892 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
894 0xff, 0xa3, // jmp *offset(%ebx)
895 0, 0, 0, 0, // replaced with offset of symbol in .got
896 0x68, // pushl immediate
897 0, 0, 0, 0, // replaced with offset into relocation table
898 0xe9, // jmp relative
899 0, 0, 0, 0 // replaced with offset to start of .plt
902 // Write out the PLT. This uses the hand-coded instructions above,
903 // and adjusts them as needed. This is all specified by the i386 ELF
904 // Processor Supplement.
907 Output_data_plt_i386::do_write(Output_file
* of
)
909 const off_t offset
= this->offset();
910 const section_size_type oview_size
=
911 convert_to_section_size_type(this->data_size());
912 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
914 const off_t got_file_offset
= this->got_plt_
->offset();
915 const section_size_type got_size
=
916 convert_to_section_size_type(this->got_plt_
->data_size());
917 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
920 unsigned char* pov
= oview
;
922 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
923 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
925 if (parameters
->options().output_is_position_independent())
926 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
929 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
930 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
931 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
933 pov
+= plt_entry_size
;
935 unsigned char* got_pov
= got_view
;
937 memset(got_pov
, 0, 12);
940 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
942 unsigned int plt_offset
= plt_entry_size
;
943 unsigned int plt_rel_offset
= 0;
944 unsigned int got_offset
= 12;
945 const unsigned int count
= this->count_
;
946 for (unsigned int i
= 0;
949 pov
+= plt_entry_size
,
951 plt_offset
+= plt_entry_size
,
952 plt_rel_offset
+= rel_size
,
955 // Set and adjust the PLT entry itself.
957 if (parameters
->options().output_is_position_independent())
959 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
960 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
964 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
965 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
970 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
971 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
972 - (plt_offset
+ plt_entry_size
));
974 // Set the entry in the GOT.
975 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
978 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
979 // the GOT to point to the actual symbol value, rather than point to
980 // the PLT entry. That will let the dynamic linker call the right
981 // function when resolving IRELATIVE relocations.
982 for (std::vector
<Global_ifunc
>::const_iterator p
=
983 this->global_ifuncs_
.begin();
984 p
!= this->global_ifuncs_
.end();
987 const Sized_symbol
<32>* ssym
=
988 static_cast<const Sized_symbol
<32>*>(p
->sym
);
989 elfcpp::Swap
<32, false>::writeval(got_view
+ p
->got_offset
,
993 for (std::vector
<Local_ifunc
>::const_iterator p
=
994 this->local_ifuncs_
.begin();
995 p
!= this->local_ifuncs_
.end();
998 const Symbol_value
<32>* psymval
=
999 p
->object
->local_symbol(p
->local_sym_index
);
1000 elfcpp::Swap
<32, false>::writeval(got_view
+ p
->got_offset
,
1001 psymval
->value(p
->object
, 0));
1004 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1005 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1007 of
->write_output_view(offset
, oview_size
, oview
);
1008 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1011 // Create the PLT section.
1014 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1016 if (this->plt_
== NULL
)
1018 // Create the GOT sections first.
1019 this->got_section(symtab
, layout
);
1021 this->plt_
= new Output_data_plt_i386(symtab
, layout
, this->got_plt_
);
1022 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1024 | elfcpp::SHF_EXECINSTR
),
1025 this->plt_
, ORDER_PLT
, false);
1027 // Make the sh_info field of .rel.plt point to .plt.
1028 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1029 rel_plt_os
->set_info_section(this->plt_
->output_section());
1033 // Create a PLT entry for a global symbol.
1036 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1038 if (gsym
->has_plt_offset())
1040 if (this->plt_
== NULL
)
1041 this->make_plt_section(symtab
, layout
);
1042 this->plt_
->add_entry(gsym
);
1045 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1048 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1049 Sized_relobj
<32, false>* relobj
,
1050 unsigned int local_sym_index
)
1052 if (relobj
->local_has_plt_offset(local_sym_index
))
1054 if (this->plt_
== NULL
)
1055 this->make_plt_section(symtab
, layout
);
1056 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(relobj
,
1058 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1061 // Return the number of entries in the PLT.
1064 Target_i386::plt_entry_count() const
1066 if (this->plt_
== NULL
)
1068 return this->plt_
->entry_count();
1071 // Return the offset of the first non-reserved PLT entry.
1074 Target_i386::first_plt_entry_offset() const
1076 return Output_data_plt_i386::first_plt_entry_offset();
1079 // Return the size of each PLT entry.
1082 Target_i386::plt_entry_size() const
1084 return Output_data_plt_i386::get_plt_entry_size();
1087 // Get the section to use for TLS_DESC relocations.
1089 Target_i386::Reloc_section
*
1090 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1092 return this->plt_section()->rel_tls_desc(layout
);
1095 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1098 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1100 if (this->tls_base_symbol_defined_
)
1103 Output_segment
* tls_segment
= layout
->tls_segment();
1104 if (tls_segment
!= NULL
)
1106 bool is_exec
= parameters
->options().output_is_executable();
1107 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1108 Symbol_table::PREDEFINED
,
1112 elfcpp::STV_HIDDEN
, 0,
1114 ? Symbol::SEGMENT_END
1115 : Symbol::SEGMENT_START
),
1118 this->tls_base_symbol_defined_
= true;
1121 // Create a GOT entry for the TLS module index.
1124 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1125 Sized_relobj
<32, false>* object
)
1127 if (this->got_mod_index_offset_
== -1U)
1129 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1130 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1131 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1132 unsigned int got_offset
= got
->add_constant(0);
1133 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1135 got
->add_constant(0);
1136 this->got_mod_index_offset_
= got_offset
;
1138 return this->got_mod_index_offset_
;
1141 // Optimize the TLS relocation type based on what we know about the
1142 // symbol. IS_FINAL is true if the final address of this symbol is
1143 // known at link time.
1145 tls::Tls_optimization
1146 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1148 // If we are generating a shared library, then we can't do anything
1150 if (parameters
->options().shared())
1151 return tls::TLSOPT_NONE
;
1155 case elfcpp::R_386_TLS_GD
:
1156 case elfcpp::R_386_TLS_GOTDESC
:
1157 case elfcpp::R_386_TLS_DESC_CALL
:
1158 // These are General-Dynamic which permits fully general TLS
1159 // access. Since we know that we are generating an executable,
1160 // we can convert this to Initial-Exec. If we also know that
1161 // this is a local symbol, we can further switch to Local-Exec.
1163 return tls::TLSOPT_TO_LE
;
1164 return tls::TLSOPT_TO_IE
;
1166 case elfcpp::R_386_TLS_LDM
:
1167 // This is Local-Dynamic, which refers to a local symbol in the
1168 // dynamic TLS block. Since we know that we generating an
1169 // executable, we can switch to Local-Exec.
1170 return tls::TLSOPT_TO_LE
;
1172 case elfcpp::R_386_TLS_LDO_32
:
1173 // Another type of Local-Dynamic relocation.
1174 return tls::TLSOPT_TO_LE
;
1176 case elfcpp::R_386_TLS_IE
:
1177 case elfcpp::R_386_TLS_GOTIE
:
1178 case elfcpp::R_386_TLS_IE_32
:
1179 // These are Initial-Exec relocs which get the thread offset
1180 // from the GOT. If we know that we are linking against the
1181 // local symbol, we can switch to Local-Exec, which links the
1182 // thread offset into the instruction.
1184 return tls::TLSOPT_TO_LE
;
1185 return tls::TLSOPT_NONE
;
1187 case elfcpp::R_386_TLS_LE
:
1188 case elfcpp::R_386_TLS_LE_32
:
1189 // When we already have Local-Exec, there is nothing further we
1191 return tls::TLSOPT_NONE
;
1198 // Get the Reference_flags for a particular relocation.
1201 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1205 case elfcpp::R_386_NONE
:
1206 case elfcpp::R_386_GNU_VTINHERIT
:
1207 case elfcpp::R_386_GNU_VTENTRY
:
1208 case elfcpp::R_386_GOTPC
:
1209 // No symbol reference.
1212 case elfcpp::R_386_32
:
1213 case elfcpp::R_386_16
:
1214 case elfcpp::R_386_8
:
1215 return Symbol::ABSOLUTE_REF
;
1217 case elfcpp::R_386_PC32
:
1218 case elfcpp::R_386_PC16
:
1219 case elfcpp::R_386_PC8
:
1220 case elfcpp::R_386_GOTOFF
:
1221 return Symbol::RELATIVE_REF
;
1223 case elfcpp::R_386_PLT32
:
1224 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1226 case elfcpp::R_386_GOT32
:
1228 return Symbol::ABSOLUTE_REF
;
1230 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1231 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1232 case elfcpp::R_386_TLS_DESC_CALL
:
1233 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1234 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1235 case elfcpp::R_386_TLS_IE
: // Initial-exec
1236 case elfcpp::R_386_TLS_IE_32
:
1237 case elfcpp::R_386_TLS_GOTIE
:
1238 case elfcpp::R_386_TLS_LE
: // Local-exec
1239 case elfcpp::R_386_TLS_LE_32
:
1240 return Symbol::TLS_REF
;
1242 case elfcpp::R_386_COPY
:
1243 case elfcpp::R_386_GLOB_DAT
:
1244 case elfcpp::R_386_JUMP_SLOT
:
1245 case elfcpp::R_386_RELATIVE
:
1246 case elfcpp::R_386_IRELATIVE
:
1247 case elfcpp::R_386_TLS_TPOFF
:
1248 case elfcpp::R_386_TLS_DTPMOD32
:
1249 case elfcpp::R_386_TLS_DTPOFF32
:
1250 case elfcpp::R_386_TLS_TPOFF32
:
1251 case elfcpp::R_386_TLS_DESC
:
1252 case elfcpp::R_386_32PLT
:
1253 case elfcpp::R_386_TLS_GD_32
:
1254 case elfcpp::R_386_TLS_GD_PUSH
:
1255 case elfcpp::R_386_TLS_GD_CALL
:
1256 case elfcpp::R_386_TLS_GD_POP
:
1257 case elfcpp::R_386_TLS_LDM_32
:
1258 case elfcpp::R_386_TLS_LDM_PUSH
:
1259 case elfcpp::R_386_TLS_LDM_CALL
:
1260 case elfcpp::R_386_TLS_LDM_POP
:
1261 case elfcpp::R_386_USED_BY_INTEL_200
:
1263 // Not expected. We will give an error later.
1268 // Report an unsupported relocation against a local symbol.
1271 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
1272 unsigned int r_type
)
1274 gold_error(_("%s: unsupported reloc %u against local symbol"),
1275 object
->name().c_str(), r_type
);
1278 // Return whether we need to make a PLT entry for a relocation of a
1279 // given type against a STT_GNU_IFUNC symbol.
1282 Target_i386::Scan::reloc_needs_plt_for_ifunc(Sized_relobj
<32, false>* object
,
1283 unsigned int r_type
)
1285 int flags
= Scan::get_reference_flags(r_type
);
1286 if (flags
& Symbol::TLS_REF
)
1287 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1288 object
->name().c_str(), r_type
);
1292 // Scan a relocation for a local symbol.
1295 Target_i386::Scan::local(Symbol_table
* symtab
,
1297 Target_i386
* target
,
1298 Sized_relobj
<32, false>* object
,
1299 unsigned int data_shndx
,
1300 Output_section
* output_section
,
1301 const elfcpp::Rel
<32, false>& reloc
,
1302 unsigned int r_type
,
1303 const elfcpp::Sym
<32, false>& lsym
)
1305 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1306 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1307 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1309 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1310 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1315 case elfcpp::R_386_NONE
:
1316 case elfcpp::R_386_GNU_VTINHERIT
:
1317 case elfcpp::R_386_GNU_VTENTRY
:
1320 case elfcpp::R_386_32
:
1321 // If building a shared library (or a position-independent
1322 // executable), we need to create a dynamic relocation for
1323 // this location. The relocation applied at link time will
1324 // apply the link-time value, so we flag the location with
1325 // an R_386_RELATIVE relocation so the dynamic loader can
1326 // relocate it easily.
1327 if (parameters
->options().output_is_position_independent())
1329 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1330 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1331 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1332 output_section
, data_shndx
,
1333 reloc
.get_r_offset());
1337 case elfcpp::R_386_16
:
1338 case elfcpp::R_386_8
:
1339 // If building a shared library (or a position-independent
1340 // executable), we need to create a dynamic relocation for
1341 // this location. Because the addend needs to remain in the
1342 // data section, we need to be careful not to apply this
1343 // relocation statically.
1344 if (parameters
->options().output_is_position_independent())
1346 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1347 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1348 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1349 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1350 data_shndx
, reloc
.get_r_offset());
1353 gold_assert(lsym
.get_st_value() == 0);
1354 unsigned int shndx
= lsym
.get_st_shndx();
1356 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1359 object
->error(_("section symbol %u has bad shndx %u"),
1362 rel_dyn
->add_local_section(object
, shndx
,
1363 r_type
, output_section
,
1364 data_shndx
, reloc
.get_r_offset());
1369 case elfcpp::R_386_PC32
:
1370 case elfcpp::R_386_PC16
:
1371 case elfcpp::R_386_PC8
:
1374 case elfcpp::R_386_PLT32
:
1375 // Since we know this is a local symbol, we can handle this as a
1379 case elfcpp::R_386_GOTOFF
:
1380 case elfcpp::R_386_GOTPC
:
1381 // We need a GOT section.
1382 target
->got_section(symtab
, layout
);
1385 case elfcpp::R_386_GOT32
:
1387 // The symbol requires a GOT entry.
1388 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1389 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1391 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1392 // lets function pointers compare correctly with shared
1393 // libraries. Otherwise we would need an IRELATIVE reloc.
1395 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1396 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1398 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1401 // If we are generating a shared object, we need to add a
1402 // dynamic RELATIVE relocation for this symbol's GOT entry.
1403 if (parameters
->options().output_is_position_independent())
1405 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1406 unsigned int got_offset
=
1407 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1408 rel_dyn
->add_local_relative(object
, r_sym
,
1409 elfcpp::R_386_RELATIVE
,
1416 // These are relocations which should only be seen by the
1417 // dynamic linker, and should never be seen here.
1418 case elfcpp::R_386_COPY
:
1419 case elfcpp::R_386_GLOB_DAT
:
1420 case elfcpp::R_386_JUMP_SLOT
:
1421 case elfcpp::R_386_RELATIVE
:
1422 case elfcpp::R_386_IRELATIVE
:
1423 case elfcpp::R_386_TLS_TPOFF
:
1424 case elfcpp::R_386_TLS_DTPMOD32
:
1425 case elfcpp::R_386_TLS_DTPOFF32
:
1426 case elfcpp::R_386_TLS_TPOFF32
:
1427 case elfcpp::R_386_TLS_DESC
:
1428 gold_error(_("%s: unexpected reloc %u in object file"),
1429 object
->name().c_str(), r_type
);
1432 // These are initial TLS relocs, which are expected when
1434 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1435 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1436 case elfcpp::R_386_TLS_DESC_CALL
:
1437 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1438 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1439 case elfcpp::R_386_TLS_IE
: // Initial-exec
1440 case elfcpp::R_386_TLS_IE_32
:
1441 case elfcpp::R_386_TLS_GOTIE
:
1442 case elfcpp::R_386_TLS_LE
: // Local-exec
1443 case elfcpp::R_386_TLS_LE_32
:
1445 bool output_is_shared
= parameters
->options().shared();
1446 const tls::Tls_optimization optimized_type
1447 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1450 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1451 if (optimized_type
== tls::TLSOPT_NONE
)
1453 // Create a pair of GOT entries for the module index and
1454 // dtv-relative offset.
1455 Output_data_got
<32, false>* got
1456 = target
->got_section(symtab
, layout
);
1457 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1458 unsigned int shndx
= lsym
.get_st_shndx();
1460 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1462 object
->error(_("local symbol %u has bad shndx %u"),
1465 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1467 target
->rel_dyn_section(layout
),
1468 elfcpp::R_386_TLS_DTPMOD32
, 0);
1470 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1471 unsupported_reloc_local(object
, r_type
);
1474 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1475 target
->define_tls_base_symbol(symtab
, layout
);
1476 if (optimized_type
== tls::TLSOPT_NONE
)
1478 // Create a double GOT entry with an R_386_TLS_DESC
1479 // reloc. The R_386_TLS_DESC reloc is resolved
1480 // lazily, so the GOT entry needs to be in an area in
1481 // .got.plt, not .got. Call got_section to make sure
1482 // the section has been created.
1483 target
->got_section(symtab
, layout
);
1484 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1485 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1486 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1488 unsigned int got_offset
= got
->add_constant(0);
1489 // The local symbol value is stored in the second
1491 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1492 // That set the GOT offset of the local symbol to
1493 // point to the second entry, but we want it to
1494 // point to the first.
1495 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1497 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1498 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1501 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1502 unsupported_reloc_local(object
, r_type
);
1505 case elfcpp::R_386_TLS_DESC_CALL
:
1508 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1509 if (optimized_type
== tls::TLSOPT_NONE
)
1511 // Create a GOT entry for the module index.
1512 target
->got_mod_index_entry(symtab
, layout
, object
);
1514 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1515 unsupported_reloc_local(object
, r_type
);
1518 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1521 case elfcpp::R_386_TLS_IE
: // Initial-exec
1522 case elfcpp::R_386_TLS_IE_32
:
1523 case elfcpp::R_386_TLS_GOTIE
:
1524 layout
->set_has_static_tls();
1525 if (optimized_type
== tls::TLSOPT_NONE
)
1527 // For the R_386_TLS_IE relocation, we need to create a
1528 // dynamic relocation when building a shared library.
1529 if (r_type
== elfcpp::R_386_TLS_IE
1530 && parameters
->options().shared())
1532 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1534 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1535 rel_dyn
->add_local_relative(object
, r_sym
,
1536 elfcpp::R_386_RELATIVE
,
1537 output_section
, data_shndx
,
1538 reloc
.get_r_offset());
1540 // Create a GOT entry for the tp-relative offset.
1541 Output_data_got
<32, false>* got
1542 = target
->got_section(symtab
, layout
);
1543 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1544 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1545 ? elfcpp::R_386_TLS_TPOFF32
1546 : elfcpp::R_386_TLS_TPOFF
);
1547 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1548 ? GOT_TYPE_TLS_OFFSET
1549 : GOT_TYPE_TLS_NOFFSET
);
1550 got
->add_local_with_rel(object
, r_sym
, got_type
,
1551 target
->rel_dyn_section(layout
),
1554 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1555 unsupported_reloc_local(object
, r_type
);
1558 case elfcpp::R_386_TLS_LE
: // Local-exec
1559 case elfcpp::R_386_TLS_LE_32
:
1560 layout
->set_has_static_tls();
1561 if (output_is_shared
)
1563 // We need to create a dynamic relocation.
1564 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1565 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1566 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1567 ? elfcpp::R_386_TLS_TPOFF32
1568 : elfcpp::R_386_TLS_TPOFF
);
1569 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1570 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1571 data_shndx
, reloc
.get_r_offset());
1581 case elfcpp::R_386_32PLT
:
1582 case elfcpp::R_386_TLS_GD_32
:
1583 case elfcpp::R_386_TLS_GD_PUSH
:
1584 case elfcpp::R_386_TLS_GD_CALL
:
1585 case elfcpp::R_386_TLS_GD_POP
:
1586 case elfcpp::R_386_TLS_LDM_32
:
1587 case elfcpp::R_386_TLS_LDM_PUSH
:
1588 case elfcpp::R_386_TLS_LDM_CALL
:
1589 case elfcpp::R_386_TLS_LDM_POP
:
1590 case elfcpp::R_386_USED_BY_INTEL_200
:
1592 unsupported_reloc_local(object
, r_type
);
1597 // Report an unsupported relocation against a global symbol.
1600 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1601 unsigned int r_type
,
1604 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1605 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1609 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1613 case elfcpp::R_386_32
:
1614 case elfcpp::R_386_16
:
1615 case elfcpp::R_386_8
:
1616 case elfcpp::R_386_GOTOFF
:
1617 case elfcpp::R_386_GOT32
:
1628 Target_i386::Scan::local_reloc_may_be_function_pointer(
1632 Sized_relobj
<32, false>* ,
1635 const elfcpp::Rel
<32, false>& ,
1636 unsigned int r_type
,
1637 const elfcpp::Sym
<32, false>&)
1639 return possible_function_pointer_reloc(r_type
);
1643 Target_i386::Scan::global_reloc_may_be_function_pointer(
1647 Sized_relobj
<32, false>* ,
1650 const elfcpp::Rel
<32, false>& ,
1651 unsigned int r_type
,
1654 return possible_function_pointer_reloc(r_type
);
1657 // Scan a relocation for a global symbol.
1660 Target_i386::Scan::global(Symbol_table
* symtab
,
1662 Target_i386
* target
,
1663 Sized_relobj
<32, false>* object
,
1664 unsigned int data_shndx
,
1665 Output_section
* output_section
,
1666 const elfcpp::Rel
<32, false>& reloc
,
1667 unsigned int r_type
,
1670 // A STT_GNU_IFUNC symbol may require a PLT entry.
1671 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1672 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1673 target
->make_plt_entry(symtab
, layout
, gsym
);
1677 case elfcpp::R_386_NONE
:
1678 case elfcpp::R_386_GNU_VTINHERIT
:
1679 case elfcpp::R_386_GNU_VTENTRY
:
1682 case elfcpp::R_386_32
:
1683 case elfcpp::R_386_16
:
1684 case elfcpp::R_386_8
:
1686 // Make a PLT entry if necessary.
1687 if (gsym
->needs_plt_entry())
1689 target
->make_plt_entry(symtab
, layout
, gsym
);
1690 // Since this is not a PC-relative relocation, we may be
1691 // taking the address of a function. In that case we need to
1692 // set the entry in the dynamic symbol table to the address of
1694 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1695 gsym
->set_needs_dynsym_value();
1697 // Make a dynamic relocation if necessary.
1698 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
1700 if (gsym
->may_need_copy_reloc())
1702 target
->copy_reloc(symtab
, layout
, object
,
1703 data_shndx
, output_section
, gsym
, reloc
);
1705 else if (r_type
== elfcpp::R_386_32
1706 && gsym
->type() == elfcpp::STT_GNU_IFUNC
1707 && gsym
->can_use_relative_reloc(false)
1708 && !gsym
->is_from_dynobj()
1709 && !gsym
->is_undefined()
1710 && !gsym
->is_preemptible())
1712 // Use an IRELATIVE reloc for a locally defined
1713 // STT_GNU_IFUNC symbol. This makes a function
1714 // address in a PIE executable match the address in a
1715 // shared library that it links against.
1716 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1717 rel_dyn
->add_symbolless_global_addend(gsym
,
1718 elfcpp::R_386_IRELATIVE
,
1721 reloc
.get_r_offset());
1723 else if (r_type
== elfcpp::R_386_32
1724 && gsym
->can_use_relative_reloc(false))
1726 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1727 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1728 output_section
, object
,
1729 data_shndx
, reloc
.get_r_offset());
1733 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1734 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1735 data_shndx
, reloc
.get_r_offset());
1741 case elfcpp::R_386_PC32
:
1742 case elfcpp::R_386_PC16
:
1743 case elfcpp::R_386_PC8
:
1745 // Make a PLT entry if necessary.
1746 if (gsym
->needs_plt_entry())
1748 // These relocations are used for function calls only in
1749 // non-PIC code. For a 32-bit relocation in a shared library,
1750 // we'll need a text relocation anyway, so we can skip the
1751 // PLT entry and let the dynamic linker bind the call directly
1752 // to the target. For smaller relocations, we should use a
1753 // PLT entry to ensure that the call can reach.
1754 if (!parameters
->options().shared()
1755 || r_type
!= elfcpp::R_386_PC32
)
1756 target
->make_plt_entry(symtab
, layout
, gsym
);
1758 // Make a dynamic relocation if necessary.
1759 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
1761 if (gsym
->may_need_copy_reloc())
1763 target
->copy_reloc(symtab
, layout
, object
,
1764 data_shndx
, output_section
, gsym
, reloc
);
1768 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1769 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1770 data_shndx
, reloc
.get_r_offset());
1776 case elfcpp::R_386_GOT32
:
1778 // The symbol requires a GOT entry.
1779 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1780 if (gsym
->final_value_is_known())
1782 // For a STT_GNU_IFUNC symbol we want the PLT address.
1783 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1784 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1786 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1790 // If this symbol is not fully resolved, we need to add a
1791 // GOT entry with a dynamic relocation.
1792 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1793 if (gsym
->is_from_dynobj()
1794 || gsym
->is_undefined()
1795 || gsym
->is_preemptible()
1796 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
1797 && parameters
->options().output_is_position_independent()))
1798 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1799 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1802 // For a STT_GNU_IFUNC symbol we want to write the PLT
1803 // offset into the GOT, so that function pointer
1804 // comparisons work correctly.
1806 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
1807 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1810 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1811 // Tell the dynamic linker to use the PLT address
1812 // when resolving relocations.
1813 if (gsym
->is_from_dynobj()
1814 && !parameters
->options().shared())
1815 gsym
->set_needs_dynsym_value();
1819 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
1820 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1828 case elfcpp::R_386_PLT32
:
1829 // If the symbol is fully resolved, this is just a PC32 reloc.
1830 // Otherwise we need a PLT entry.
1831 if (gsym
->final_value_is_known())
1833 // If building a shared library, we can also skip the PLT entry
1834 // if the symbol is defined in the output file and is protected
1836 if (gsym
->is_defined()
1837 && !gsym
->is_from_dynobj()
1838 && !gsym
->is_preemptible())
1840 target
->make_plt_entry(symtab
, layout
, gsym
);
1843 case elfcpp::R_386_GOTOFF
:
1844 case elfcpp::R_386_GOTPC
:
1845 // We need a GOT section.
1846 target
->got_section(symtab
, layout
);
1849 // These are relocations which should only be seen by the
1850 // dynamic linker, and should never be seen here.
1851 case elfcpp::R_386_COPY
:
1852 case elfcpp::R_386_GLOB_DAT
:
1853 case elfcpp::R_386_JUMP_SLOT
:
1854 case elfcpp::R_386_RELATIVE
:
1855 case elfcpp::R_386_IRELATIVE
:
1856 case elfcpp::R_386_TLS_TPOFF
:
1857 case elfcpp::R_386_TLS_DTPMOD32
:
1858 case elfcpp::R_386_TLS_DTPOFF32
:
1859 case elfcpp::R_386_TLS_TPOFF32
:
1860 case elfcpp::R_386_TLS_DESC
:
1861 gold_error(_("%s: unexpected reloc %u in object file"),
1862 object
->name().c_str(), r_type
);
1865 // These are initial tls relocs, which are expected when
1867 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1868 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1869 case elfcpp::R_386_TLS_DESC_CALL
:
1870 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1871 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1872 case elfcpp::R_386_TLS_IE
: // Initial-exec
1873 case elfcpp::R_386_TLS_IE_32
:
1874 case elfcpp::R_386_TLS_GOTIE
:
1875 case elfcpp::R_386_TLS_LE
: // Local-exec
1876 case elfcpp::R_386_TLS_LE_32
:
1878 const bool is_final
= gsym
->final_value_is_known();
1879 const tls::Tls_optimization optimized_type
1880 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1883 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1884 if (optimized_type
== tls::TLSOPT_NONE
)
1886 // Create a pair of GOT entries for the module index and
1887 // dtv-relative offset.
1888 Output_data_got
<32, false>* got
1889 = target
->got_section(symtab
, layout
);
1890 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1891 target
->rel_dyn_section(layout
),
1892 elfcpp::R_386_TLS_DTPMOD32
,
1893 elfcpp::R_386_TLS_DTPOFF32
);
1895 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1897 // Create a GOT entry for the tp-relative offset.
1898 Output_data_got
<32, false>* got
1899 = target
->got_section(symtab
, layout
);
1900 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1901 target
->rel_dyn_section(layout
),
1902 elfcpp::R_386_TLS_TPOFF
);
1904 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1905 unsupported_reloc_global(object
, r_type
, gsym
);
1908 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1909 target
->define_tls_base_symbol(symtab
, layout
);
1910 if (optimized_type
== tls::TLSOPT_NONE
)
1912 // Create a double GOT entry with an R_386_TLS_DESC
1913 // reloc. The R_386_TLS_DESC reloc is resolved
1914 // lazily, so the GOT entry needs to be in an area in
1915 // .got.plt, not .got. Call got_section to make sure
1916 // the section has been created.
1917 target
->got_section(symtab
, layout
);
1918 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1919 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1920 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1921 elfcpp::R_386_TLS_DESC
, 0);
1923 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1925 // Create a GOT entry for the tp-relative offset.
1926 Output_data_got
<32, false>* got
1927 = target
->got_section(symtab
, layout
);
1928 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1929 target
->rel_dyn_section(layout
),
1930 elfcpp::R_386_TLS_TPOFF
);
1932 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1933 unsupported_reloc_global(object
, r_type
, gsym
);
1936 case elfcpp::R_386_TLS_DESC_CALL
:
1939 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1940 if (optimized_type
== tls::TLSOPT_NONE
)
1942 // Create a GOT entry for the module index.
1943 target
->got_mod_index_entry(symtab
, layout
, object
);
1945 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1946 unsupported_reloc_global(object
, r_type
, gsym
);
1949 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1952 case elfcpp::R_386_TLS_IE
: // Initial-exec
1953 case elfcpp::R_386_TLS_IE_32
:
1954 case elfcpp::R_386_TLS_GOTIE
:
1955 layout
->set_has_static_tls();
1956 if (optimized_type
== tls::TLSOPT_NONE
)
1958 // For the R_386_TLS_IE relocation, we need to create a
1959 // dynamic relocation when building a shared library.
1960 if (r_type
== elfcpp::R_386_TLS_IE
1961 && parameters
->options().shared())
1963 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1964 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1965 output_section
, object
,
1967 reloc
.get_r_offset());
1969 // Create a GOT entry for the tp-relative offset.
1970 Output_data_got
<32, false>* got
1971 = target
->got_section(symtab
, layout
);
1972 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1973 ? elfcpp::R_386_TLS_TPOFF32
1974 : elfcpp::R_386_TLS_TPOFF
);
1975 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1976 ? GOT_TYPE_TLS_OFFSET
1977 : GOT_TYPE_TLS_NOFFSET
);
1978 got
->add_global_with_rel(gsym
, got_type
,
1979 target
->rel_dyn_section(layout
),
1982 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1983 unsupported_reloc_global(object
, r_type
, gsym
);
1986 case elfcpp::R_386_TLS_LE
: // Local-exec
1987 case elfcpp::R_386_TLS_LE_32
:
1988 layout
->set_has_static_tls();
1989 if (parameters
->options().shared())
1991 // We need to create a dynamic relocation.
1992 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1993 ? elfcpp::R_386_TLS_TPOFF32
1994 : elfcpp::R_386_TLS_TPOFF
);
1995 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1996 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1997 data_shndx
, reloc
.get_r_offset());
2007 case elfcpp::R_386_32PLT
:
2008 case elfcpp::R_386_TLS_GD_32
:
2009 case elfcpp::R_386_TLS_GD_PUSH
:
2010 case elfcpp::R_386_TLS_GD_CALL
:
2011 case elfcpp::R_386_TLS_GD_POP
:
2012 case elfcpp::R_386_TLS_LDM_32
:
2013 case elfcpp::R_386_TLS_LDM_PUSH
:
2014 case elfcpp::R_386_TLS_LDM_CALL
:
2015 case elfcpp::R_386_TLS_LDM_POP
:
2016 case elfcpp::R_386_USED_BY_INTEL_200
:
2018 unsupported_reloc_global(object
, r_type
, gsym
);
2023 // Process relocations for gc.
2026 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2028 Sized_relobj
<32, false>* object
,
2029 unsigned int data_shndx
,
2031 const unsigned char* prelocs
,
2033 Output_section
* output_section
,
2034 bool needs_special_offset_handling
,
2035 size_t local_symbol_count
,
2036 const unsigned char* plocal_symbols
)
2038 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2040 Target_i386::Relocatable_size_for_reloc
>(
2049 needs_special_offset_handling
,
2054 // Scan relocations for a section.
2057 Target_i386::scan_relocs(Symbol_table
* symtab
,
2059 Sized_relobj
<32, false>* object
,
2060 unsigned int data_shndx
,
2061 unsigned int sh_type
,
2062 const unsigned char* prelocs
,
2064 Output_section
* output_section
,
2065 bool needs_special_offset_handling
,
2066 size_t local_symbol_count
,
2067 const unsigned char* plocal_symbols
)
2069 if (sh_type
== elfcpp::SHT_RELA
)
2071 gold_error(_("%s: unsupported RELA reloc section"),
2072 object
->name().c_str());
2076 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2086 needs_special_offset_handling
,
2091 // Finalize the sections.
2094 Target_i386::do_finalize_sections(
2096 const Input_objects
*,
2097 Symbol_table
* symtab
)
2099 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2101 : this->plt_
->rel_plt());
2102 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2103 this->rel_dyn_
, true, false);
2105 // Emit any relocs we saved in an attempt to avoid generating COPY
2107 if (this->copy_relocs_
.any_saved_relocs())
2108 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2110 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2111 // the .got.plt section.
2112 Symbol
* sym
= this->global_offset_table_
;
2115 uint32_t data_size
= this->got_plt_
->current_data_size();
2116 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2120 // Return whether a direct absolute static relocation needs to be applied.
2121 // In cases where Scan::local() or Scan::global() has created
2122 // a dynamic relocation other than R_386_RELATIVE, the addend
2123 // of the relocation is carried in the data, and we must not
2124 // apply the static relocation.
2127 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2128 unsigned int r_type
,
2130 Output_section
* output_section
)
2132 // If the output section is not allocated, then we didn't call
2133 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2135 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2138 int ref_flags
= Scan::get_reference_flags(r_type
);
2140 // For local symbols, we will have created a non-RELATIVE dynamic
2141 // relocation only if (a) the output is position independent,
2142 // (b) the relocation is absolute (not pc- or segment-relative), and
2143 // (c) the relocation is not 32 bits wide.
2145 return !(parameters
->options().output_is_position_independent()
2146 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2149 // For global symbols, we use the same helper routines used in the
2150 // scan pass. If we did not create a dynamic relocation, or if we
2151 // created a RELATIVE dynamic relocation, we should apply the static
2153 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2154 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2155 && gsym
->can_use_relative_reloc(ref_flags
2156 & Symbol::FUNCTION_CALL
);
2157 return !has_dyn
|| is_rel
;
2160 // Perform a relocation.
2163 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2164 Target_i386
* target
,
2165 Output_section
* output_section
,
2167 const elfcpp::Rel
<32, false>& rel
,
2168 unsigned int r_type
,
2169 const Sized_symbol
<32>* gsym
,
2170 const Symbol_value
<32>* psymval
,
2171 unsigned char* view
,
2172 elfcpp::Elf_types
<32>::Elf_Addr address
,
2173 section_size_type view_size
)
2175 if (this->skip_call_tls_get_addr_
)
2177 if ((r_type
!= elfcpp::R_386_PLT32
2178 && r_type
!= elfcpp::R_386_PC32
)
2180 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2181 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2182 _("missing expected TLS relocation"));
2185 this->skip_call_tls_get_addr_
= false;
2190 const Sized_relobj
<32, false>* object
= relinfo
->object
;
2192 // Pick the value to use for symbols defined in shared objects.
2193 Symbol_value
<32> symval
;
2195 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2196 && r_type
== elfcpp::R_386_32
2197 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2198 && gsym
->can_use_relative_reloc(false)
2199 && !gsym
->is_from_dynobj()
2200 && !gsym
->is_undefined()
2201 && !gsym
->is_preemptible())
2203 // In this case we are generating a R_386_IRELATIVE reloc. We
2204 // want to use the real value of the symbol, not the PLT offset.
2206 else if (gsym
!= NULL
2207 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2209 symval
.set_output_value(target
->plt_section()->address()
2210 + gsym
->plt_offset());
2213 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2215 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2216 if (object
->local_has_plt_offset(r_sym
))
2218 symval
.set_output_value(target
->plt_section()->address()
2219 + object
->local_plt_offset(r_sym
));
2224 // Get the GOT offset if needed.
2225 // The GOT pointer points to the end of the GOT section.
2226 // We need to subtract the size of the GOT section to get
2227 // the actual offset to use in the relocation.
2228 bool have_got_offset
= false;
2229 unsigned int got_offset
= 0;
2232 case elfcpp::R_386_GOT32
:
2235 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2236 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2237 - target
->got_size());
2241 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2242 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2243 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2244 - target
->got_size());
2246 have_got_offset
= true;
2255 case elfcpp::R_386_NONE
:
2256 case elfcpp::R_386_GNU_VTINHERIT
:
2257 case elfcpp::R_386_GNU_VTENTRY
:
2260 case elfcpp::R_386_32
:
2261 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2262 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2265 case elfcpp::R_386_PC32
:
2266 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2267 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2270 case elfcpp::R_386_16
:
2271 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2272 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2275 case elfcpp::R_386_PC16
:
2276 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2277 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2280 case elfcpp::R_386_8
:
2281 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2282 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2285 case elfcpp::R_386_PC8
:
2286 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2287 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2290 case elfcpp::R_386_PLT32
:
2291 gold_assert(gsym
== NULL
2292 || gsym
->has_plt_offset()
2293 || gsym
->final_value_is_known()
2294 || (gsym
->is_defined()
2295 && !gsym
->is_from_dynobj()
2296 && !gsym
->is_preemptible()));
2297 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2300 case elfcpp::R_386_GOT32
:
2301 gold_assert(have_got_offset
);
2302 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2305 case elfcpp::R_386_GOTOFF
:
2307 elfcpp::Elf_types
<32>::Elf_Addr value
;
2308 value
= (psymval
->value(object
, 0)
2309 - target
->got_plt_section()->address());
2310 Relocate_functions
<32, false>::rel32(view
, value
);
2314 case elfcpp::R_386_GOTPC
:
2316 elfcpp::Elf_types
<32>::Elf_Addr value
;
2317 value
= target
->got_plt_section()->address();
2318 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2322 case elfcpp::R_386_COPY
:
2323 case elfcpp::R_386_GLOB_DAT
:
2324 case elfcpp::R_386_JUMP_SLOT
:
2325 case elfcpp::R_386_RELATIVE
:
2326 case elfcpp::R_386_IRELATIVE
:
2327 // These are outstanding tls relocs, which are unexpected when
2329 case elfcpp::R_386_TLS_TPOFF
:
2330 case elfcpp::R_386_TLS_DTPMOD32
:
2331 case elfcpp::R_386_TLS_DTPOFF32
:
2332 case elfcpp::R_386_TLS_TPOFF32
:
2333 case elfcpp::R_386_TLS_DESC
:
2334 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2335 _("unexpected reloc %u in object file"),
2339 // These are initial tls relocs, which are expected when
2341 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2342 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2343 case elfcpp::R_386_TLS_DESC_CALL
:
2344 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2345 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2346 case elfcpp::R_386_TLS_IE
: // Initial-exec
2347 case elfcpp::R_386_TLS_IE_32
:
2348 case elfcpp::R_386_TLS_GOTIE
:
2349 case elfcpp::R_386_TLS_LE
: // Local-exec
2350 case elfcpp::R_386_TLS_LE_32
:
2351 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2352 view
, address
, view_size
);
2355 case elfcpp::R_386_32PLT
:
2356 case elfcpp::R_386_TLS_GD_32
:
2357 case elfcpp::R_386_TLS_GD_PUSH
:
2358 case elfcpp::R_386_TLS_GD_CALL
:
2359 case elfcpp::R_386_TLS_GD_POP
:
2360 case elfcpp::R_386_TLS_LDM_32
:
2361 case elfcpp::R_386_TLS_LDM_PUSH
:
2362 case elfcpp::R_386_TLS_LDM_CALL
:
2363 case elfcpp::R_386_TLS_LDM_POP
:
2364 case elfcpp::R_386_USED_BY_INTEL_200
:
2366 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2367 _("unsupported reloc %u"),
2375 // Perform a TLS relocation.
2378 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2379 Target_i386
* target
,
2381 const elfcpp::Rel
<32, false>& rel
,
2382 unsigned int r_type
,
2383 const Sized_symbol
<32>* gsym
,
2384 const Symbol_value
<32>* psymval
,
2385 unsigned char* view
,
2386 elfcpp::Elf_types
<32>::Elf_Addr
,
2387 section_size_type view_size
)
2389 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2391 const Sized_relobj
<32, false>* object
= relinfo
->object
;
2393 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2395 const bool is_final
= (gsym
== NULL
2396 ? !parameters
->options().shared()
2397 : gsym
->final_value_is_known());
2398 const tls::Tls_optimization optimized_type
2399 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2402 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2403 if (optimized_type
== tls::TLSOPT_TO_LE
)
2405 gold_assert(tls_segment
!= NULL
);
2406 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2407 rel
, r_type
, value
, view
,
2413 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2414 ? GOT_TYPE_TLS_NOFFSET
2415 : GOT_TYPE_TLS_PAIR
);
2416 unsigned int got_offset
;
2419 gold_assert(gsym
->has_got_offset(got_type
));
2420 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2424 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2425 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2426 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2427 - target
->got_size());
2429 if (optimized_type
== tls::TLSOPT_TO_IE
)
2431 gold_assert(tls_segment
!= NULL
);
2432 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2433 got_offset
, view
, view_size
);
2436 else if (optimized_type
== tls::TLSOPT_NONE
)
2438 // Relocate the field with the offset of the pair of GOT
2440 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2444 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2445 _("unsupported reloc %u"),
2449 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2450 case elfcpp::R_386_TLS_DESC_CALL
:
2451 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2452 if (optimized_type
== tls::TLSOPT_TO_LE
)
2454 gold_assert(tls_segment
!= NULL
);
2455 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2456 rel
, r_type
, value
, view
,
2462 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2463 ? GOT_TYPE_TLS_NOFFSET
2464 : GOT_TYPE_TLS_DESC
);
2465 unsigned int got_offset
= 0;
2466 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2467 && optimized_type
== tls::TLSOPT_NONE
)
2469 // We created GOT entries in the .got.tlsdesc portion of
2470 // the .got.plt section, but the offset stored in the
2471 // symbol is the offset within .got.tlsdesc.
2472 got_offset
= (target
->got_size()
2473 + target
->got_plt_section()->data_size());
2477 gold_assert(gsym
->has_got_offset(got_type
));
2478 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2482 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2483 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2484 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2485 - target
->got_size());
2487 if (optimized_type
== tls::TLSOPT_TO_IE
)
2489 gold_assert(tls_segment
!= NULL
);
2490 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2491 got_offset
, view
, view_size
);
2494 else if (optimized_type
== tls::TLSOPT_NONE
)
2496 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2498 // Relocate the field with the offset of the pair of GOT
2500 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2505 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2506 _("unsupported reloc %u"),
2510 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2511 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2513 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2514 _("both SUN and GNU model "
2515 "TLS relocations"));
2518 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2519 if (optimized_type
== tls::TLSOPT_TO_LE
)
2521 gold_assert(tls_segment
!= NULL
);
2522 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2523 value
, view
, view_size
);
2526 else if (optimized_type
== tls::TLSOPT_NONE
)
2528 // Relocate the field with the offset of the GOT entry for
2529 // the module index.
2530 unsigned int got_offset
;
2531 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2532 - target
->got_size());
2533 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2536 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2537 _("unsupported reloc %u"),
2541 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2542 if (optimized_type
== tls::TLSOPT_TO_LE
)
2544 // This reloc can appear in debugging sections, in which
2545 // case we must not convert to local-exec. We decide what
2546 // to do based on whether the section is marked as
2547 // containing executable code. That is what the GNU linker
2549 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
2550 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
2552 gold_assert(tls_segment
!= NULL
);
2553 value
-= tls_segment
->memsz();
2556 Relocate_functions
<32, false>::rel32(view
, value
);
2559 case elfcpp::R_386_TLS_IE
: // Initial-exec
2560 case elfcpp::R_386_TLS_GOTIE
:
2561 case elfcpp::R_386_TLS_IE_32
:
2562 if (optimized_type
== tls::TLSOPT_TO_LE
)
2564 gold_assert(tls_segment
!= NULL
);
2565 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2566 rel
, r_type
, value
, view
,
2570 else if (optimized_type
== tls::TLSOPT_NONE
)
2572 // Relocate the field with the offset of the GOT entry for
2573 // the tp-relative offset of the symbol.
2574 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2575 ? GOT_TYPE_TLS_OFFSET
2576 : GOT_TYPE_TLS_NOFFSET
);
2577 unsigned int got_offset
;
2580 gold_assert(gsym
->has_got_offset(got_type
));
2581 got_offset
= gsym
->got_offset(got_type
);
2585 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2586 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2587 got_offset
= object
->local_got_offset(r_sym
, got_type
);
2589 // For the R_386_TLS_IE relocation, we need to apply the
2590 // absolute address of the GOT entry.
2591 if (r_type
== elfcpp::R_386_TLS_IE
)
2592 got_offset
+= target
->got_plt_section()->address();
2593 // All GOT offsets are relative to the end of the GOT.
2594 got_offset
-= target
->got_size();
2595 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2598 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2599 _("unsupported reloc %u"),
2603 case elfcpp::R_386_TLS_LE
: // Local-exec
2604 // If we're creating a shared library, a dynamic relocation will
2605 // have been created for this location, so do not apply it now.
2606 if (!parameters
->options().shared())
2608 gold_assert(tls_segment
!= NULL
);
2609 value
-= tls_segment
->memsz();
2610 Relocate_functions
<32, false>::rel32(view
, value
);
2614 case elfcpp::R_386_TLS_LE_32
:
2615 // If we're creating a shared library, a dynamic relocation will
2616 // have been created for this location, so do not apply it now.
2617 if (!parameters
->options().shared())
2619 gold_assert(tls_segment
!= NULL
);
2620 value
= tls_segment
->memsz() - value
;
2621 Relocate_functions
<32, false>::rel32(view
, value
);
2627 // Do a relocation in which we convert a TLS General-Dynamic to a
2631 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2633 Output_segment
* tls_segment
,
2634 const elfcpp::Rel
<32, false>& rel
,
2636 elfcpp::Elf_types
<32>::Elf_Addr value
,
2637 unsigned char* view
,
2638 section_size_type view_size
)
2640 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2641 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2642 // leal foo(%reg),%eax; call ___tls_get_addr
2643 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2645 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2646 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2648 unsigned char op1
= view
[-1];
2649 unsigned char op2
= view
[-2];
2651 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2652 op2
== 0x8d || op2
== 0x04);
2653 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2659 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2660 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2661 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2662 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2663 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2667 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2668 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2669 if (rel
.get_r_offset() + 9 < view_size
2672 // There is a trailing nop. Use the size byte subl.
2673 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2678 // Use the five byte subl.
2679 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2683 value
= tls_segment
->memsz() - value
;
2684 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2686 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2688 this->skip_call_tls_get_addr_
= true;
2691 // Do a relocation in which we convert a TLS General-Dynamic to an
2695 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2698 const elfcpp::Rel
<32, false>& rel
,
2700 elfcpp::Elf_types
<32>::Elf_Addr value
,
2701 unsigned char* view
,
2702 section_size_type view_size
)
2704 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2705 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2707 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2708 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2710 unsigned char op1
= view
[-1];
2711 unsigned char op2
= view
[-2];
2713 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2714 op2
== 0x8d || op2
== 0x04);
2715 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2719 // FIXME: For now, support only the first (SIB) form.
2720 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2724 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2725 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2726 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2727 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2728 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2732 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2733 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2734 if (rel
.get_r_offset() + 9 < view_size
2737 // FIXME: This is not the right instruction sequence.
2738 // There is a trailing nop. Use the size byte subl.
2739 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2744 // FIXME: This is not the right instruction sequence.
2745 // Use the five byte subl.
2746 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2750 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2752 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2754 this->skip_call_tls_get_addr_
= true;
2757 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2758 // General-Dynamic to a Local-Exec.
2761 Target_i386::Relocate::tls_desc_gd_to_le(
2762 const Relocate_info
<32, false>* relinfo
,
2764 Output_segment
* tls_segment
,
2765 const elfcpp::Rel
<32, false>& rel
,
2766 unsigned int r_type
,
2767 elfcpp::Elf_types
<32>::Elf_Addr value
,
2768 unsigned char* view
,
2769 section_size_type view_size
)
2771 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2773 // leal foo@TLSDESC(%ebx), %eax
2774 // ==> leal foo@NTPOFF, %eax
2775 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2776 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2777 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2778 view
[-2] == 0x8d && view
[-1] == 0x83);
2780 value
-= tls_segment
->memsz();
2781 Relocate_functions
<32, false>::rel32(view
, value
);
2785 // call *foo@TLSCALL(%eax)
2787 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2788 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2789 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2790 view
[0] == 0xff && view
[1] == 0x10);
2796 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2797 // General-Dynamic to an Initial-Exec.
2800 Target_i386::Relocate::tls_desc_gd_to_ie(
2801 const Relocate_info
<32, false>* relinfo
,
2804 const elfcpp::Rel
<32, false>& rel
,
2805 unsigned int r_type
,
2806 elfcpp::Elf_types
<32>::Elf_Addr value
,
2807 unsigned char* view
,
2808 section_size_type view_size
)
2810 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2812 // leal foo@TLSDESC(%ebx), %eax
2813 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2814 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2815 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2816 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2817 view
[-2] == 0x8d && view
[-1] == 0x83);
2819 Relocate_functions
<32, false>::rel32(view
, value
);
2823 // call *foo@TLSCALL(%eax)
2825 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2826 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2827 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2828 view
[0] == 0xff && view
[1] == 0x10);
2834 // Do a relocation in which we convert a TLS Local-Dynamic to a
2838 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2841 const elfcpp::Rel
<32, false>& rel
,
2843 elfcpp::Elf_types
<32>::Elf_Addr
,
2844 unsigned char* view
,
2845 section_size_type view_size
)
2847 // leal foo(%reg), %eax; call ___tls_get_addr
2848 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2850 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2851 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2853 // FIXME: Does this test really always pass?
2854 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2855 view
[-2] == 0x8d && view
[-1] == 0x83);
2857 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2859 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2861 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2863 this->skip_call_tls_get_addr_
= true;
2866 // Do a relocation in which we convert a TLS Initial-Exec to a
2870 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2872 Output_segment
* tls_segment
,
2873 const elfcpp::Rel
<32, false>& rel
,
2874 unsigned int r_type
,
2875 elfcpp::Elf_types
<32>::Elf_Addr value
,
2876 unsigned char* view
,
2877 section_size_type view_size
)
2879 // We have to actually change the instructions, which means that we
2880 // need to examine the opcodes to figure out which instruction we
2882 if (r_type
== elfcpp::R_386_TLS_IE
)
2884 // movl %gs:XX,%eax ==> movl $YY,%eax
2885 // movl %gs:XX,%reg ==> movl $YY,%reg
2886 // addl %gs:XX,%reg ==> addl $YY,%reg
2887 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2888 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2890 unsigned char op1
= view
[-1];
2893 // movl XX,%eax ==> movl $YY,%eax
2898 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2900 unsigned char op2
= view
[-2];
2903 // movl XX,%reg ==> movl $YY,%reg
2904 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2905 (op1
& 0xc7) == 0x05);
2907 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2909 else if (op2
== 0x03)
2911 // addl XX,%reg ==> addl $YY,%reg
2912 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2913 (op1
& 0xc7) == 0x05);
2915 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2918 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2923 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2924 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2925 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2926 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2927 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2929 unsigned char op1
= view
[-1];
2930 unsigned char op2
= view
[-2];
2931 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2932 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2935 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2937 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2939 else if (op2
== 0x2b)
2941 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2943 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2945 else if (op2
== 0x03)
2947 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2949 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2952 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2955 value
= tls_segment
->memsz() - value
;
2956 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2959 Relocate_functions
<32, false>::rel32(view
, value
);
2962 // Relocate section data.
2965 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2966 unsigned int sh_type
,
2967 const unsigned char* prelocs
,
2969 Output_section
* output_section
,
2970 bool needs_special_offset_handling
,
2971 unsigned char* view
,
2972 elfcpp::Elf_types
<32>::Elf_Addr address
,
2973 section_size_type view_size
,
2974 const Reloc_symbol_changes
* reloc_symbol_changes
)
2976 gold_assert(sh_type
== elfcpp::SHT_REL
);
2978 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2979 Target_i386::Relocate
>(
2985 needs_special_offset_handling
,
2989 reloc_symbol_changes
);
2992 // Return the size of a relocation while scanning during a relocatable
2996 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2997 unsigned int r_type
,
3002 case elfcpp::R_386_NONE
:
3003 case elfcpp::R_386_GNU_VTINHERIT
:
3004 case elfcpp::R_386_GNU_VTENTRY
:
3005 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3006 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3007 case elfcpp::R_386_TLS_DESC_CALL
:
3008 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3009 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3010 case elfcpp::R_386_TLS_IE
: // Initial-exec
3011 case elfcpp::R_386_TLS_IE_32
:
3012 case elfcpp::R_386_TLS_GOTIE
:
3013 case elfcpp::R_386_TLS_LE
: // Local-exec
3014 case elfcpp::R_386_TLS_LE_32
:
3017 case elfcpp::R_386_32
:
3018 case elfcpp::R_386_PC32
:
3019 case elfcpp::R_386_GOT32
:
3020 case elfcpp::R_386_PLT32
:
3021 case elfcpp::R_386_GOTOFF
:
3022 case elfcpp::R_386_GOTPC
:
3025 case elfcpp::R_386_16
:
3026 case elfcpp::R_386_PC16
:
3029 case elfcpp::R_386_8
:
3030 case elfcpp::R_386_PC8
:
3033 // These are relocations which should only be seen by the
3034 // dynamic linker, and should never be seen here.
3035 case elfcpp::R_386_COPY
:
3036 case elfcpp::R_386_GLOB_DAT
:
3037 case elfcpp::R_386_JUMP_SLOT
:
3038 case elfcpp::R_386_RELATIVE
:
3039 case elfcpp::R_386_IRELATIVE
:
3040 case elfcpp::R_386_TLS_TPOFF
:
3041 case elfcpp::R_386_TLS_DTPMOD32
:
3042 case elfcpp::R_386_TLS_DTPOFF32
:
3043 case elfcpp::R_386_TLS_TPOFF32
:
3044 case elfcpp::R_386_TLS_DESC
:
3045 object
->error(_("unexpected reloc %u in object file"), r_type
);
3048 case elfcpp::R_386_32PLT
:
3049 case elfcpp::R_386_TLS_GD_32
:
3050 case elfcpp::R_386_TLS_GD_PUSH
:
3051 case elfcpp::R_386_TLS_GD_CALL
:
3052 case elfcpp::R_386_TLS_GD_POP
:
3053 case elfcpp::R_386_TLS_LDM_32
:
3054 case elfcpp::R_386_TLS_LDM_PUSH
:
3055 case elfcpp::R_386_TLS_LDM_CALL
:
3056 case elfcpp::R_386_TLS_LDM_POP
:
3057 case elfcpp::R_386_USED_BY_INTEL_200
:
3059 object
->error(_("unsupported reloc %u in object file"), r_type
);
3064 // Scan the relocs during a relocatable link.
3067 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3069 Sized_relobj
<32, false>* object
,
3070 unsigned int data_shndx
,
3071 unsigned int sh_type
,
3072 const unsigned char* prelocs
,
3074 Output_section
* output_section
,
3075 bool needs_special_offset_handling
,
3076 size_t local_symbol_count
,
3077 const unsigned char* plocal_symbols
,
3078 Relocatable_relocs
* rr
)
3080 gold_assert(sh_type
== elfcpp::SHT_REL
);
3082 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3083 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3085 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3086 Scan_relocatable_relocs
>(
3094 needs_special_offset_handling
,
3100 // Relocate a section during a relocatable link.
3103 Target_i386::relocate_for_relocatable(
3104 const Relocate_info
<32, false>* relinfo
,
3105 unsigned int sh_type
,
3106 const unsigned char* prelocs
,
3108 Output_section
* output_section
,
3109 off_t offset_in_output_section
,
3110 const Relocatable_relocs
* rr
,
3111 unsigned char* view
,
3112 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3113 section_size_type view_size
,
3114 unsigned char* reloc_view
,
3115 section_size_type reloc_view_size
)
3117 gold_assert(sh_type
== elfcpp::SHT_REL
);
3119 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
3124 offset_in_output_section
,
3133 // Return the value to use for a dynamic which requires special
3134 // treatment. This is how we support equality comparisons of function
3135 // pointers across shared library boundaries, as described in the
3136 // processor specific ABI supplement.
3139 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3141 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3142 return this->plt_section()->address() + gsym
->plt_offset();
3145 // Return a string used to fill a code section with nops to take up
3146 // the specified length.
3149 Target_i386::do_code_fill(section_size_type length
) const
3153 // Build a jmp instruction to skip over the bytes.
3154 unsigned char jmp
[5];
3156 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3157 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3158 + std::string(length
- 5, '\0'));
3161 // Nop sequences of various lengths.
3162 const char nop1
[1] = { 0x90 }; // nop
3163 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
3164 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
3165 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
3166 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
3167 0x00 }; // leal 0(%esi,1),%esi
3168 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3170 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3172 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
3173 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3174 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
3175 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
3177 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3178 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3180 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3181 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3183 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3184 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3185 0x00, 0x00, 0x00, 0x00 };
3186 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3187 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3188 0x27, 0x00, 0x00, 0x00,
3190 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3191 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3192 0xbc, 0x27, 0x00, 0x00,
3194 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3195 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3196 0x90, 0x90, 0x90, 0x90,
3199 const char* nops
[16] = {
3201 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3202 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3205 return std::string(nops
[length
], length
);
3208 // Return whether SYM should be treated as a call to a non-split
3209 // function. We don't want that to be true of a call to a
3210 // get_pc_thunk function.
3213 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3215 return (sym
->type() == elfcpp::STT_FUNC
3216 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3219 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3220 // compiled with -fsplit-stack. The function calls non-split-stack
3221 // code. We have to change the function so that it always ensures
3222 // that it has enough stack space to run some random function.
3225 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3226 section_offset_type fnoffset
,
3227 section_size_type fnsize
,
3228 unsigned char* view
,
3229 section_size_type view_size
,
3231 std::string
* to
) const
3233 // The function starts with a comparison of the stack pointer and a
3234 // field in the TCB. This is followed by a jump.
3237 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3240 // We will call __morestack if the carry flag is set after this
3241 // comparison. We turn the comparison into an stc instruction
3243 view
[fnoffset
] = '\xf9';
3244 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3246 // lea NN(%esp),%ecx
3247 // lea NN(%esp),%edx
3248 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3249 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3252 // This is loading an offset from the stack pointer for a
3253 // comparison. The offset is negative, so we decrease the
3254 // offset by the amount of space we need for the stack. This
3255 // means we will avoid calling __morestack if there happens to
3256 // be plenty of space on the stack already.
3257 unsigned char* pval
= view
+ fnoffset
+ 3;
3258 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3259 val
-= parameters
->options().split_stack_adjust_size();
3260 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3264 if (!object
->has_no_split_stack())
3265 object
->error(_("failed to match split-stack sequence at "
3266 "section %u offset %0zx"),
3267 shndx
, static_cast<size_t>(fnoffset
));
3271 // We have to change the function so that it calls
3272 // __morestack_non_split instead of __morestack. The former will
3273 // allocate additional stack space.
3274 *from
= "__morestack";
3275 *to
= "__morestack_non_split";
3278 // The selector for i386 object files.
3280 class Target_selector_i386
: public Target_selector_freebsd
3283 Target_selector_i386()
3284 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3285 "elf32-i386", "elf32-i386-freebsd")
3289 do_instantiate_target()
3290 { return new Target_i386(); }
3293 Target_selector_i386 target_selector_i386
;
3295 } // End anonymous namespace.