1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
49 // A class to handle the PLT data.
51 class Output_data_plt_i386
: public Output_section_data
54 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
56 Output_data_plt_i386(Symbol_table
*, Layout
*, Output_data_space
*);
58 // Add an entry to the PLT.
60 add_entry(Symbol
* gsym
);
62 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
64 add_local_ifunc_entry(Sized_relobj_file
<32, false>* relobj
,
65 unsigned int local_sym_index
);
67 // Return the .rel.plt section data.
70 { return this->rel_
; }
72 // Return where the TLS_DESC relocations should go.
74 rel_tls_desc(Layout
*);
76 // Return the number of PLT entries.
79 { return this->count_
; }
81 // Return the offset of the first non-reserved PLT entry.
83 first_plt_entry_offset()
84 { return plt_entry_size
; }
86 // Return the size of a PLT entry.
89 { return plt_entry_size
; }
93 do_adjust_output_section(Output_section
* os
);
95 // Write to a map file.
97 do_print_to_mapfile(Mapfile
* mapfile
) const
98 { mapfile
->print_output_data(this, _("** PLT")); }
101 // The size of an entry in the PLT.
102 static const int plt_entry_size
= 16;
104 // The first entry in the PLT for an executable.
105 static const unsigned char exec_first_plt_entry
[plt_entry_size
];
107 // The first entry in the PLT for a shared object.
108 static const unsigned char dyn_first_plt_entry
[plt_entry_size
];
110 // Other entries in the PLT for an executable.
111 static const unsigned char exec_plt_entry
[plt_entry_size
];
113 // Other entries in the PLT for a shared object.
114 static const unsigned char dyn_plt_entry
[plt_entry_size
];
116 // The .eh_frame unwind information for the PLT.
117 static const int plt_eh_frame_cie_size
= 16;
118 static const int plt_eh_frame_fde_size
= 32;
119 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
120 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
122 // Set the final size.
124 set_final_data_size()
125 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
127 // Write out the PLT data.
129 do_write(Output_file
*);
131 // We keep a list of global STT_GNU_IFUNC symbols, each with its
132 // offset in the GOT.
136 unsigned int got_offset
;
139 // We keep a list of local STT_GNU_IFUNC symbols, each with its
140 // offset in the GOT.
143 Sized_relobj_file
<32, false>* object
;
144 unsigned int local_sym_index
;
145 unsigned int got_offset
;
148 // The reloc section.
150 // The TLS_DESC relocations, if necessary. These must follow the
151 // regular PLT relocs.
152 Reloc_section
* tls_desc_rel_
;
153 // The .got.plt section.
154 Output_data_space
* got_plt_
;
155 // The number of PLT entries.
157 // Global STT_GNU_IFUNC symbols.
158 std::vector
<Global_ifunc
> global_ifuncs_
;
159 // Local STT_GNU_IFUNC symbols.
160 std::vector
<Local_ifunc
> local_ifuncs_
;
163 // The i386 target class.
164 // TLS info comes from
165 // http://people.redhat.com/drepper/tls.pdf
166 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
168 class Target_i386
: public Sized_target
<32, false>
171 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
174 : Sized_target
<32, false>(&i386_info
),
175 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_tlsdesc_(NULL
),
176 global_offset_table_(NULL
), rel_dyn_(NULL
),
177 copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
178 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
181 // Process the relocations to determine unreferenced sections for
182 // garbage collection.
184 gc_process_relocs(Symbol_table
* symtab
,
186 Sized_relobj_file
<32, false>* object
,
187 unsigned int data_shndx
,
188 unsigned int sh_type
,
189 const unsigned char* prelocs
,
191 Output_section
* output_section
,
192 bool needs_special_offset_handling
,
193 size_t local_symbol_count
,
194 const unsigned char* plocal_symbols
);
196 // Scan the relocations to look for symbol adjustments.
198 scan_relocs(Symbol_table
* symtab
,
200 Sized_relobj_file
<32, false>* object
,
201 unsigned int data_shndx
,
202 unsigned int sh_type
,
203 const unsigned char* prelocs
,
205 Output_section
* output_section
,
206 bool needs_special_offset_handling
,
207 size_t local_symbol_count
,
208 const unsigned char* plocal_symbols
);
210 // Finalize the sections.
212 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
214 // Return the value to use for a dynamic which requires special
217 do_dynsym_value(const Symbol
*) const;
219 // Relocate a section.
221 relocate_section(const Relocate_info
<32, false>*,
222 unsigned int sh_type
,
223 const unsigned char* prelocs
,
225 Output_section
* output_section
,
226 bool needs_special_offset_handling
,
228 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
229 section_size_type view_size
,
230 const Reloc_symbol_changes
*);
232 // Scan the relocs during a relocatable link.
234 scan_relocatable_relocs(Symbol_table
* symtab
,
236 Sized_relobj_file
<32, false>* object
,
237 unsigned int data_shndx
,
238 unsigned int sh_type
,
239 const unsigned char* prelocs
,
241 Output_section
* output_section
,
242 bool needs_special_offset_handling
,
243 size_t local_symbol_count
,
244 const unsigned char* plocal_symbols
,
245 Relocatable_relocs
*);
247 // Relocate a section during a relocatable link.
249 relocate_for_relocatable(const Relocate_info
<32, false>*,
250 unsigned int sh_type
,
251 const unsigned char* prelocs
,
253 Output_section
* output_section
,
254 off_t offset_in_output_section
,
255 const Relocatable_relocs
*,
257 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
258 section_size_type view_size
,
259 unsigned char* reloc_view
,
260 section_size_type reloc_view_size
);
262 // Return a string used to fill a code section with nops.
264 do_code_fill(section_size_type length
) const;
266 // Return whether SYM is defined by the ABI.
268 do_is_defined_by_abi(const Symbol
* sym
) const
269 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
271 // Return whether a symbol name implies a local label. The UnixWare
272 // 2.1 cc generates temporary symbols that start with .X, so we
273 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
274 // If so, we should move the .X recognition into
275 // Target::do_is_local_label_name.
277 do_is_local_label_name(const char* name
) const
279 if (name
[0] == '.' && name
[1] == 'X')
281 return Target::do_is_local_label_name(name
);
284 // Return the PLT section.
286 do_plt_section_for_global(const Symbol
*) const
287 { return this->plt_section(); }
290 do_plt_section_for_local(const Relobj
*, unsigned int) const
291 { return this->plt_section(); }
293 // We can tell whether we take the address of a function.
295 do_can_check_for_function_pointers() const
298 // Return whether SYM is call to a non-split function.
300 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
302 // Adjust -fsplit-stack code which calls non-split-stack code.
304 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
305 section_offset_type fnoffset
, section_size_type fnsize
,
306 unsigned char* view
, section_size_type view_size
,
307 std::string
* from
, std::string
* to
) const;
309 // Return the size of the GOT section.
313 gold_assert(this->got_
!= NULL
);
314 return this->got_
->data_size();
317 // Return the number of entries in the GOT.
319 got_entry_count() const
321 if (this->got_
== NULL
)
323 return this->got_size() / 4;
326 // Return the number of entries in the PLT.
328 plt_entry_count() const;
330 // Return the offset of the first non-reserved PLT entry.
332 first_plt_entry_offset() const;
334 // Return the size of each PLT entry.
336 plt_entry_size() const;
339 // The class which scans relocations.
344 get_reference_flags(unsigned int r_type
);
347 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
348 Sized_relobj_file
<32, false>* object
,
349 unsigned int data_shndx
,
350 Output_section
* output_section
,
351 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
352 const elfcpp::Sym
<32, false>& lsym
);
355 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
356 Sized_relobj_file
<32, false>* object
,
357 unsigned int data_shndx
,
358 Output_section
* output_section
,
359 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
363 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
365 Sized_relobj_file
<32, false>* object
,
366 unsigned int data_shndx
,
367 Output_section
* output_section
,
368 const elfcpp::Rel
<32, false>& reloc
,
370 const elfcpp::Sym
<32, false>& lsym
);
373 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
375 Sized_relobj_file
<32, false>* object
,
376 unsigned int data_shndx
,
377 Output_section
* output_section
,
378 const elfcpp::Rel
<32, false>& reloc
,
383 possible_function_pointer_reloc(unsigned int r_type
);
386 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
387 unsigned int r_type
);
390 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
393 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
397 // The class which implements relocation.
402 : skip_call_tls_get_addr_(false),
403 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
408 if (this->skip_call_tls_get_addr_
)
410 // FIXME: This needs to specify the location somehow.
411 gold_error(_("missing expected TLS relocation"));
415 // Return whether the static relocation needs to be applied.
417 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
420 Output_section
* output_section
);
422 // Do a relocation. Return false if the caller should not issue
423 // any warnings about this relocation.
425 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
426 size_t relnum
, const elfcpp::Rel
<32, false>&,
427 unsigned int r_type
, const Sized_symbol
<32>*,
428 const Symbol_value
<32>*,
429 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
433 // Do a TLS relocation.
435 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
436 size_t relnum
, const elfcpp::Rel
<32, false>&,
437 unsigned int r_type
, const Sized_symbol
<32>*,
438 const Symbol_value
<32>*,
439 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
442 // Do a TLS General-Dynamic to Initial-Exec transition.
444 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
445 Output_segment
* tls_segment
,
446 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
447 elfcpp::Elf_types
<32>::Elf_Addr value
,
449 section_size_type view_size
);
451 // Do a TLS General-Dynamic to Local-Exec transition.
453 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
454 Output_segment
* tls_segment
,
455 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
456 elfcpp::Elf_types
<32>::Elf_Addr value
,
458 section_size_type view_size
);
460 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
463 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
464 Output_segment
* tls_segment
,
465 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
466 elfcpp::Elf_types
<32>::Elf_Addr value
,
468 section_size_type view_size
);
470 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
473 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
474 Output_segment
* tls_segment
,
475 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
476 elfcpp::Elf_types
<32>::Elf_Addr value
,
478 section_size_type view_size
);
480 // Do a TLS Local-Dynamic to Local-Exec transition.
482 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
483 Output_segment
* tls_segment
,
484 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
485 elfcpp::Elf_types
<32>::Elf_Addr value
,
487 section_size_type view_size
);
489 // Do a TLS Initial-Exec to Local-Exec transition.
491 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
492 Output_segment
* tls_segment
,
493 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
494 elfcpp::Elf_types
<32>::Elf_Addr value
,
496 section_size_type view_size
);
498 // We need to keep track of which type of local dynamic relocation
499 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
500 enum Local_dynamic_type
507 // This is set if we should skip the next reloc, which should be a
508 // PLT32 reloc against ___tls_get_addr.
509 bool skip_call_tls_get_addr_
;
510 // The type of local dynamic relocation we have seen in the section
511 // being relocated, if any.
512 Local_dynamic_type local_dynamic_type_
;
515 // A class which returns the size required for a relocation type,
516 // used while scanning relocs during a relocatable link.
517 class Relocatable_size_for_reloc
521 get_size_for_reloc(unsigned int, Relobj
*);
524 // Adjust TLS relocation type based on the options and whether this
525 // is a local symbol.
526 static tls::Tls_optimization
527 optimize_tls_reloc(bool is_final
, int r_type
);
529 // Get the GOT section, creating it if necessary.
530 Output_data_got
<32, false>*
531 got_section(Symbol_table
*, Layout
*);
533 // Get the GOT PLT section.
535 got_plt_section() const
537 gold_assert(this->got_plt_
!= NULL
);
538 return this->got_plt_
;
541 // Get the GOT section for TLSDESC entries.
542 Output_data_got
<32, false>*
543 got_tlsdesc_section() const
545 gold_assert(this->got_tlsdesc_
!= NULL
);
546 return this->got_tlsdesc_
;
549 // Create the PLT section.
551 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
553 // Create a PLT entry for a global symbol.
555 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
557 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
559 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
560 Sized_relobj_file
<32, false>* relobj
,
561 unsigned int local_sym_index
);
563 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
565 define_tls_base_symbol(Symbol_table
*, Layout
*);
567 // Create a GOT entry for the TLS module index.
569 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
570 Sized_relobj_file
<32, false>* object
);
572 // Get the PLT section.
573 Output_data_plt_i386
*
576 gold_assert(this->plt_
!= NULL
);
580 // Get the dynamic reloc section, creating it if necessary.
582 rel_dyn_section(Layout
*);
584 // Get the section to use for TLS_DESC relocations.
586 rel_tls_desc_section(Layout
*) const;
588 // Add a potential copy relocation.
590 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
591 Sized_relobj_file
<32, false>* object
,
592 unsigned int shndx
, Output_section
* output_section
,
593 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
595 this->copy_relocs_
.copy_reloc(symtab
, layout
,
596 symtab
->get_sized_symbol
<32>(sym
),
597 object
, shndx
, output_section
, reloc
,
598 this->rel_dyn_section(layout
));
601 // Information about this specific target which we pass to the
602 // general Target structure.
603 static const Target::Target_info i386_info
;
605 // The types of GOT entries needed for this platform.
606 // These values are exposed to the ABI in an incremental link.
607 // Do not renumber existing values without changing the version
608 // number of the .gnu_incremental_inputs section.
611 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
612 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
613 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
614 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
615 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
619 Output_data_got
<32, false>* got_
;
621 Output_data_plt_i386
* plt_
;
622 // The GOT PLT section.
623 Output_data_space
* got_plt_
;
624 // The GOT section for TLSDESC relocations.
625 Output_data_got
<32, false>* got_tlsdesc_
;
626 // The _GLOBAL_OFFSET_TABLE_ symbol.
627 Symbol
* global_offset_table_
;
628 // The dynamic reloc section.
629 Reloc_section
* rel_dyn_
;
630 // Relocs saved to avoid a COPY reloc.
631 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
632 // Space for variables copied with a COPY reloc.
633 Output_data_space
* dynbss_
;
634 // Offset of the GOT entry for the TLS module index.
635 unsigned int got_mod_index_offset_
;
636 // True if the _TLS_MODULE_BASE_ symbol has been defined.
637 bool tls_base_symbol_defined_
;
640 const Target::Target_info
Target_i386::i386_info
=
643 false, // is_big_endian
644 elfcpp::EM_386
, // machine_code
645 false, // has_make_symbol
646 false, // has_resolve
647 true, // has_code_fill
648 true, // is_default_stack_executable
649 true, // can_icf_inline_merge_sections
651 "/usr/lib/libc.so.1", // dynamic_linker
652 0x08048000, // default_text_segment_address
653 0x1000, // abi_pagesize (overridable by -z max-page-size)
654 0x1000, // common_pagesize (overridable by -z common-page-size)
655 elfcpp::SHN_UNDEF
, // small_common_shndx
656 elfcpp::SHN_UNDEF
, // large_common_shndx
657 0, // small_common_section_flags
658 0, // large_common_section_flags
659 NULL
, // attributes_section
660 NULL
// attributes_vendor
663 // Get the GOT section, creating it if necessary.
665 Output_data_got
<32, false>*
666 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
668 if (this->got_
== NULL
)
670 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
672 this->got_
= new Output_data_got
<32, false>();
674 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
676 | elfcpp::SHF_WRITE
),
677 this->got_
, ORDER_RELRO_LAST
, true);
679 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
680 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
682 | elfcpp::SHF_WRITE
),
683 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
686 // The first three entries are reserved.
687 this->got_plt_
->set_current_data_size(3 * 4);
689 // Those bytes can go into the relro segment.
690 layout
->increase_relro(3 * 4);
692 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
693 this->global_offset_table_
=
694 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
695 Symbol_table::PREDEFINED
,
697 0, 0, elfcpp::STT_OBJECT
,
699 elfcpp::STV_HIDDEN
, 0,
702 // If there are any TLSDESC relocations, they get GOT entries in
703 // .got.plt after the jump slot entries.
704 this->got_tlsdesc_
= new Output_data_got
<32, false>();
705 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
707 | elfcpp::SHF_WRITE
),
709 ORDER_NON_RELRO_FIRST
, false);
715 // Get the dynamic reloc section, creating it if necessary.
717 Target_i386::Reloc_section
*
718 Target_i386::rel_dyn_section(Layout
* layout
)
720 if (this->rel_dyn_
== NULL
)
722 gold_assert(layout
!= NULL
);
723 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
724 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
725 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
726 ORDER_DYNAMIC_RELOCS
, false);
728 return this->rel_dyn_
;
731 // Create the PLT section. The ordinary .got section is an argument,
732 // since we need to refer to the start. We also create our own .got
733 // section just for PLT entries.
735 Output_data_plt_i386::Output_data_plt_i386(Symbol_table
* symtab
,
737 Output_data_space
* got_plt
)
738 : Output_section_data(16), tls_desc_rel_(NULL
), got_plt_(got_plt
), count_(0),
739 global_ifuncs_(), local_ifuncs_()
741 this->rel_
= new Reloc_section(false);
742 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
743 elfcpp::SHF_ALLOC
, this->rel_
,
744 ORDER_DYNAMIC_PLT_RELOCS
, false);
746 if (parameters
->doing_static_link())
748 // A statically linked executable will only have a .rel.plt
749 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
750 // symbols. The library will use these symbols to locate the
751 // IRELATIVE relocs at program startup time.
752 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
753 Symbol_table::PREDEFINED
,
754 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
755 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
757 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
758 Symbol_table::PREDEFINED
,
759 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
760 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
764 // Add unwind information if requested.
765 if (parameters
->options().ld_generated_unwind_info())
766 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
767 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
771 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
773 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
774 // linker, and so do we.
778 // Add an entry to the PLT.
781 Output_data_plt_i386::add_entry(Symbol
* gsym
)
783 gold_assert(!gsym
->has_plt_offset());
785 // Note that when setting the PLT offset we skip the initial
786 // reserved PLT entry.
787 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
791 section_offset_type got_offset
= this->got_plt_
->current_data_size();
793 // Every PLT entry needs a GOT entry which points back to the PLT
794 // entry (this will be changed by the dynamic linker, normally
795 // lazily when the function is called).
796 this->got_plt_
->set_current_data_size(got_offset
+ 4);
798 // Every PLT entry needs a reloc.
799 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
800 && gsym
->can_use_relative_reloc(false))
802 this->rel_
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
803 this->got_plt_
, got_offset
);
804 struct Global_ifunc gi
;
806 gi
.got_offset
= got_offset
;
807 this->global_ifuncs_
.push_back(gi
);
811 gsym
->set_needs_dynsym_entry();
812 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
816 // Note that we don't need to save the symbol. The contents of the
817 // PLT are independent of which symbols are used. The symbols only
818 // appear in the relocations.
821 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
825 Output_data_plt_i386::add_local_ifunc_entry(
826 Sized_relobj_file
<32, false>* relobj
,
827 unsigned int local_sym_index
)
829 unsigned int plt_offset
= (this->count_
+ 1) * plt_entry_size
;
832 section_offset_type got_offset
= this->got_plt_
->current_data_size();
834 // Every PLT entry needs a GOT entry which points back to the PLT
836 this->got_plt_
->set_current_data_size(got_offset
+ 4);
838 // Every PLT entry needs a reloc.
839 this->rel_
->add_symbolless_local_addend(relobj
, local_sym_index
,
840 elfcpp::R_386_IRELATIVE
,
841 this->got_plt_
, got_offset
);
843 struct Local_ifunc li
;
845 li
.local_sym_index
= local_sym_index
;
846 li
.got_offset
= got_offset
;
847 this->local_ifuncs_
.push_back(li
);
852 // Return where the TLS_DESC relocations should go, creating it if
853 // necessary. These follow the JUMP_SLOT relocations.
855 Output_data_plt_i386::Reloc_section
*
856 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
858 if (this->tls_desc_rel_
== NULL
)
860 this->tls_desc_rel_
= new Reloc_section(false);
861 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
862 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
863 ORDER_DYNAMIC_PLT_RELOCS
, false);
864 gold_assert(this->tls_desc_rel_
->output_section() ==
865 this->rel_
->output_section());
867 return this->tls_desc_rel_
;
870 // The first entry in the PLT for an executable.
872 const unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
874 0xff, 0x35, // pushl contents of memory address
875 0, 0, 0, 0, // replaced with address of .got + 4
876 0xff, 0x25, // jmp indirect
877 0, 0, 0, 0, // replaced with address of .got + 8
881 // The first entry in the PLT for a shared object.
883 const unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
885 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
886 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
890 // Subsequent entries in the PLT for an executable.
892 const unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
894 0xff, 0x25, // jmp indirect
895 0, 0, 0, 0, // replaced with address 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 // Subsequent entries in the PLT for a shared object.
904 const unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
906 0xff, 0xa3, // jmp *offset(%ebx)
907 0, 0, 0, 0, // replaced with offset of symbol in .got
908 0x68, // pushl immediate
909 0, 0, 0, 0, // replaced with offset into relocation table
910 0xe9, // jmp relative
911 0, 0, 0, 0 // replaced with offset to start of .plt
914 // The .eh_frame unwind information for the PLT.
917 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
920 'z', // Augmentation: augmentation size included.
921 'R', // Augmentation: FDE encoding included.
922 '\0', // End of augmentation string.
923 1, // Code alignment factor.
924 0x7c, // Data alignment factor.
925 8, // Return address column.
926 1, // Augmentation size.
927 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
928 | elfcpp::DW_EH_PE_sdata4
),
929 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
930 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
931 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
936 Output_data_plt_i386::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
938 0, 0, 0, 0, // Replaced with offset to .plt.
939 0, 0, 0, 0, // Replaced with size of .plt.
940 0, // Augmentation size.
941 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
942 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
943 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
944 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
945 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
947 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
948 elfcpp::DW_OP_breg8
, 0, // Push %eip.
949 elfcpp::DW_OP_lit15
, // Push 0xf.
950 elfcpp::DW_OP_and
, // & (%eip & 0xf).
951 elfcpp::DW_OP_lit11
, // Push 0xb.
952 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
953 elfcpp::DW_OP_lit2
, // Push 2.
954 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
955 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
956 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
962 // Write out the PLT. This uses the hand-coded instructions above,
963 // and adjusts them as needed. This is all specified by the i386 ELF
964 // Processor Supplement.
967 Output_data_plt_i386::do_write(Output_file
* of
)
969 const off_t offset
= this->offset();
970 const section_size_type oview_size
=
971 convert_to_section_size_type(this->data_size());
972 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
974 const off_t got_file_offset
= this->got_plt_
->offset();
975 const section_size_type got_size
=
976 convert_to_section_size_type(this->got_plt_
->data_size());
977 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
980 unsigned char* pov
= oview
;
982 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
983 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
985 if (parameters
->options().output_is_position_independent())
986 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
989 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
990 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
991 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
993 pov
+= plt_entry_size
;
995 unsigned char* got_pov
= got_view
;
997 memset(got_pov
, 0, 12);
1000 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1002 unsigned int plt_offset
= plt_entry_size
;
1003 unsigned int plt_rel_offset
= 0;
1004 unsigned int got_offset
= 12;
1005 const unsigned int count
= this->count_
;
1006 for (unsigned int i
= 0;
1009 pov
+= plt_entry_size
,
1011 plt_offset
+= plt_entry_size
,
1012 plt_rel_offset
+= rel_size
,
1015 // Set and adjust the PLT entry itself.
1017 if (parameters
->options().output_is_position_independent())
1019 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
1020 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1024 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
1025 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1030 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1031 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
1032 - (plt_offset
+ plt_entry_size
));
1034 // Set the entry in the GOT.
1035 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
1038 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1039 // the GOT to point to the actual symbol value, rather than point to
1040 // the PLT entry. That will let the dynamic linker call the right
1041 // function when resolving IRELATIVE relocations.
1042 for (std::vector
<Global_ifunc
>::const_iterator p
=
1043 this->global_ifuncs_
.begin();
1044 p
!= this->global_ifuncs_
.end();
1047 const Sized_symbol
<32>* ssym
=
1048 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1049 elfcpp::Swap
<32, false>::writeval(got_view
+ p
->got_offset
,
1053 for (std::vector
<Local_ifunc
>::const_iterator p
=
1054 this->local_ifuncs_
.begin();
1055 p
!= this->local_ifuncs_
.end();
1058 const Symbol_value
<32>* psymval
=
1059 p
->object
->local_symbol(p
->local_sym_index
);
1060 elfcpp::Swap
<32, false>::writeval(got_view
+ p
->got_offset
,
1061 psymval
->value(p
->object
, 0));
1064 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1065 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1067 of
->write_output_view(offset
, oview_size
, oview
);
1068 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1071 // Create the PLT section.
1074 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1076 if (this->plt_
== NULL
)
1078 // Create the GOT sections first.
1079 this->got_section(symtab
, layout
);
1081 this->plt_
= new Output_data_plt_i386(symtab
, layout
, this->got_plt_
);
1082 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1084 | elfcpp::SHF_EXECINSTR
),
1085 this->plt_
, ORDER_PLT
, false);
1087 // Make the sh_info field of .rel.plt point to .plt.
1088 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1089 rel_plt_os
->set_info_section(this->plt_
->output_section());
1093 // Create a PLT entry for a global symbol.
1096 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1098 if (gsym
->has_plt_offset())
1100 if (this->plt_
== NULL
)
1101 this->make_plt_section(symtab
, layout
);
1102 this->plt_
->add_entry(gsym
);
1105 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1108 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1109 Sized_relobj_file
<32, false>* relobj
,
1110 unsigned int local_sym_index
)
1112 if (relobj
->local_has_plt_offset(local_sym_index
))
1114 if (this->plt_
== NULL
)
1115 this->make_plt_section(symtab
, layout
);
1116 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(relobj
,
1118 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1121 // Return the number of entries in the PLT.
1124 Target_i386::plt_entry_count() const
1126 if (this->plt_
== NULL
)
1128 return this->plt_
->entry_count();
1131 // Return the offset of the first non-reserved PLT entry.
1134 Target_i386::first_plt_entry_offset() const
1136 return Output_data_plt_i386::first_plt_entry_offset();
1139 // Return the size of each PLT entry.
1142 Target_i386::plt_entry_size() const
1144 return Output_data_plt_i386::get_plt_entry_size();
1147 // Get the section to use for TLS_DESC relocations.
1149 Target_i386::Reloc_section
*
1150 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1152 return this->plt_section()->rel_tls_desc(layout
);
1155 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1158 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1160 if (this->tls_base_symbol_defined_
)
1163 Output_segment
* tls_segment
= layout
->tls_segment();
1164 if (tls_segment
!= NULL
)
1166 bool is_exec
= parameters
->options().output_is_executable();
1167 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1168 Symbol_table::PREDEFINED
,
1172 elfcpp::STV_HIDDEN
, 0,
1174 ? Symbol::SEGMENT_END
1175 : Symbol::SEGMENT_START
),
1178 this->tls_base_symbol_defined_
= true;
1181 // Create a GOT entry for the TLS module index.
1184 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1185 Sized_relobj_file
<32, false>* object
)
1187 if (this->got_mod_index_offset_
== -1U)
1189 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1190 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1191 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1192 unsigned int got_offset
= got
->add_constant(0);
1193 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1195 got
->add_constant(0);
1196 this->got_mod_index_offset_
= got_offset
;
1198 return this->got_mod_index_offset_
;
1201 // Optimize the TLS relocation type based on what we know about the
1202 // symbol. IS_FINAL is true if the final address of this symbol is
1203 // known at link time.
1205 tls::Tls_optimization
1206 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1208 // If we are generating a shared library, then we can't do anything
1210 if (parameters
->options().shared())
1211 return tls::TLSOPT_NONE
;
1215 case elfcpp::R_386_TLS_GD
:
1216 case elfcpp::R_386_TLS_GOTDESC
:
1217 case elfcpp::R_386_TLS_DESC_CALL
:
1218 // These are General-Dynamic which permits fully general TLS
1219 // access. Since we know that we are generating an executable,
1220 // we can convert this to Initial-Exec. If we also know that
1221 // this is a local symbol, we can further switch to Local-Exec.
1223 return tls::TLSOPT_TO_LE
;
1224 return tls::TLSOPT_TO_IE
;
1226 case elfcpp::R_386_TLS_LDM
:
1227 // This is Local-Dynamic, which refers to a local symbol in the
1228 // dynamic TLS block. Since we know that we generating an
1229 // executable, we can switch to Local-Exec.
1230 return tls::TLSOPT_TO_LE
;
1232 case elfcpp::R_386_TLS_LDO_32
:
1233 // Another type of Local-Dynamic relocation.
1234 return tls::TLSOPT_TO_LE
;
1236 case elfcpp::R_386_TLS_IE
:
1237 case elfcpp::R_386_TLS_GOTIE
:
1238 case elfcpp::R_386_TLS_IE_32
:
1239 // These are Initial-Exec relocs which get the thread offset
1240 // from the GOT. If we know that we are linking against the
1241 // local symbol, we can switch to Local-Exec, which links the
1242 // thread offset into the instruction.
1244 return tls::TLSOPT_TO_LE
;
1245 return tls::TLSOPT_NONE
;
1247 case elfcpp::R_386_TLS_LE
:
1248 case elfcpp::R_386_TLS_LE_32
:
1249 // When we already have Local-Exec, there is nothing further we
1251 return tls::TLSOPT_NONE
;
1258 // Get the Reference_flags for a particular relocation.
1261 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1265 case elfcpp::R_386_NONE
:
1266 case elfcpp::R_386_GNU_VTINHERIT
:
1267 case elfcpp::R_386_GNU_VTENTRY
:
1268 case elfcpp::R_386_GOTPC
:
1269 // No symbol reference.
1272 case elfcpp::R_386_32
:
1273 case elfcpp::R_386_16
:
1274 case elfcpp::R_386_8
:
1275 return Symbol::ABSOLUTE_REF
;
1277 case elfcpp::R_386_PC32
:
1278 case elfcpp::R_386_PC16
:
1279 case elfcpp::R_386_PC8
:
1280 case elfcpp::R_386_GOTOFF
:
1281 return Symbol::RELATIVE_REF
;
1283 case elfcpp::R_386_PLT32
:
1284 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1286 case elfcpp::R_386_GOT32
:
1288 return Symbol::ABSOLUTE_REF
;
1290 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1291 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1292 case elfcpp::R_386_TLS_DESC_CALL
:
1293 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1294 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1295 case elfcpp::R_386_TLS_IE
: // Initial-exec
1296 case elfcpp::R_386_TLS_IE_32
:
1297 case elfcpp::R_386_TLS_GOTIE
:
1298 case elfcpp::R_386_TLS_LE
: // Local-exec
1299 case elfcpp::R_386_TLS_LE_32
:
1300 return Symbol::TLS_REF
;
1302 case elfcpp::R_386_COPY
:
1303 case elfcpp::R_386_GLOB_DAT
:
1304 case elfcpp::R_386_JUMP_SLOT
:
1305 case elfcpp::R_386_RELATIVE
:
1306 case elfcpp::R_386_IRELATIVE
:
1307 case elfcpp::R_386_TLS_TPOFF
:
1308 case elfcpp::R_386_TLS_DTPMOD32
:
1309 case elfcpp::R_386_TLS_DTPOFF32
:
1310 case elfcpp::R_386_TLS_TPOFF32
:
1311 case elfcpp::R_386_TLS_DESC
:
1312 case elfcpp::R_386_32PLT
:
1313 case elfcpp::R_386_TLS_GD_32
:
1314 case elfcpp::R_386_TLS_GD_PUSH
:
1315 case elfcpp::R_386_TLS_GD_CALL
:
1316 case elfcpp::R_386_TLS_GD_POP
:
1317 case elfcpp::R_386_TLS_LDM_32
:
1318 case elfcpp::R_386_TLS_LDM_PUSH
:
1319 case elfcpp::R_386_TLS_LDM_CALL
:
1320 case elfcpp::R_386_TLS_LDM_POP
:
1321 case elfcpp::R_386_USED_BY_INTEL_200
:
1323 // Not expected. We will give an error later.
1328 // Report an unsupported relocation against a local symbol.
1331 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1332 unsigned int r_type
)
1334 gold_error(_("%s: unsupported reloc %u against local symbol"),
1335 object
->name().c_str(), r_type
);
1338 // Return whether we need to make a PLT entry for a relocation of a
1339 // given type against a STT_GNU_IFUNC symbol.
1342 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1343 Sized_relobj_file
<32, false>* object
,
1344 unsigned int r_type
)
1346 int flags
= Scan::get_reference_flags(r_type
);
1347 if (flags
& Symbol::TLS_REF
)
1348 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1349 object
->name().c_str(), r_type
);
1353 // Scan a relocation for a local symbol.
1356 Target_i386::Scan::local(Symbol_table
* symtab
,
1358 Target_i386
* target
,
1359 Sized_relobj_file
<32, false>* object
,
1360 unsigned int data_shndx
,
1361 Output_section
* output_section
,
1362 const elfcpp::Rel
<32, false>& reloc
,
1363 unsigned int r_type
,
1364 const elfcpp::Sym
<32, false>& lsym
)
1366 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1367 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1368 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1370 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1371 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1376 case elfcpp::R_386_NONE
:
1377 case elfcpp::R_386_GNU_VTINHERIT
:
1378 case elfcpp::R_386_GNU_VTENTRY
:
1381 case elfcpp::R_386_32
:
1382 // If building a shared library (or a position-independent
1383 // executable), we need to create a dynamic relocation for
1384 // this location. The relocation applied at link time will
1385 // apply the link-time value, so we flag the location with
1386 // an R_386_RELATIVE relocation so the dynamic loader can
1387 // relocate it easily.
1388 if (parameters
->options().output_is_position_independent())
1390 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1391 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1392 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1393 output_section
, data_shndx
,
1394 reloc
.get_r_offset());
1398 case elfcpp::R_386_16
:
1399 case elfcpp::R_386_8
:
1400 // If building a shared library (or a position-independent
1401 // executable), we need to create a dynamic relocation for
1402 // this location. Because the addend needs to remain in the
1403 // data section, we need to be careful not to apply this
1404 // relocation statically.
1405 if (parameters
->options().output_is_position_independent())
1407 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1408 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1409 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1410 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1411 data_shndx
, reloc
.get_r_offset());
1414 gold_assert(lsym
.get_st_value() == 0);
1415 unsigned int shndx
= lsym
.get_st_shndx();
1417 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1420 object
->error(_("section symbol %u has bad shndx %u"),
1423 rel_dyn
->add_local_section(object
, shndx
,
1424 r_type
, output_section
,
1425 data_shndx
, reloc
.get_r_offset());
1430 case elfcpp::R_386_PC32
:
1431 case elfcpp::R_386_PC16
:
1432 case elfcpp::R_386_PC8
:
1435 case elfcpp::R_386_PLT32
:
1436 // Since we know this is a local symbol, we can handle this as a
1440 case elfcpp::R_386_GOTOFF
:
1441 case elfcpp::R_386_GOTPC
:
1442 // We need a GOT section.
1443 target
->got_section(symtab
, layout
);
1446 case elfcpp::R_386_GOT32
:
1448 // The symbol requires a GOT entry.
1449 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1450 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1452 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1453 // lets function pointers compare correctly with shared
1454 // libraries. Otherwise we would need an IRELATIVE reloc.
1456 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1457 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1459 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1462 // If we are generating a shared object, we need to add a
1463 // dynamic RELATIVE relocation for this symbol's GOT entry.
1464 if (parameters
->options().output_is_position_independent())
1466 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1467 unsigned int got_offset
=
1468 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1469 rel_dyn
->add_local_relative(object
, r_sym
,
1470 elfcpp::R_386_RELATIVE
,
1477 // These are relocations which should only be seen by the
1478 // dynamic linker, and should never be seen here.
1479 case elfcpp::R_386_COPY
:
1480 case elfcpp::R_386_GLOB_DAT
:
1481 case elfcpp::R_386_JUMP_SLOT
:
1482 case elfcpp::R_386_RELATIVE
:
1483 case elfcpp::R_386_IRELATIVE
:
1484 case elfcpp::R_386_TLS_TPOFF
:
1485 case elfcpp::R_386_TLS_DTPMOD32
:
1486 case elfcpp::R_386_TLS_DTPOFF32
:
1487 case elfcpp::R_386_TLS_TPOFF32
:
1488 case elfcpp::R_386_TLS_DESC
:
1489 gold_error(_("%s: unexpected reloc %u in object file"),
1490 object
->name().c_str(), r_type
);
1493 // These are initial TLS relocs, which are expected when
1495 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1496 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1497 case elfcpp::R_386_TLS_DESC_CALL
:
1498 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1499 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1500 case elfcpp::R_386_TLS_IE
: // Initial-exec
1501 case elfcpp::R_386_TLS_IE_32
:
1502 case elfcpp::R_386_TLS_GOTIE
:
1503 case elfcpp::R_386_TLS_LE
: // Local-exec
1504 case elfcpp::R_386_TLS_LE_32
:
1506 bool output_is_shared
= parameters
->options().shared();
1507 const tls::Tls_optimization optimized_type
1508 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1511 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1512 if (optimized_type
== tls::TLSOPT_NONE
)
1514 // Create a pair of GOT entries for the module index and
1515 // dtv-relative offset.
1516 Output_data_got
<32, false>* got
1517 = target
->got_section(symtab
, layout
);
1518 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1519 unsigned int shndx
= lsym
.get_st_shndx();
1521 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1523 object
->error(_("local symbol %u has bad shndx %u"),
1526 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1528 target
->rel_dyn_section(layout
),
1529 elfcpp::R_386_TLS_DTPMOD32
, 0);
1531 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1532 unsupported_reloc_local(object
, r_type
);
1535 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1536 target
->define_tls_base_symbol(symtab
, layout
);
1537 if (optimized_type
== tls::TLSOPT_NONE
)
1539 // Create a double GOT entry with an R_386_TLS_DESC
1540 // reloc. The R_386_TLS_DESC reloc is resolved
1541 // lazily, so the GOT entry needs to be in an area in
1542 // .got.plt, not .got. Call got_section to make sure
1543 // the section has been created.
1544 target
->got_section(symtab
, layout
);
1545 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1546 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1547 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1549 unsigned int got_offset
= got
->add_constant(0);
1550 // The local symbol value is stored in the second
1552 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1553 // That set the GOT offset of the local symbol to
1554 // point to the second entry, but we want it to
1555 // point to the first.
1556 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1558 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1559 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1562 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1563 unsupported_reloc_local(object
, r_type
);
1566 case elfcpp::R_386_TLS_DESC_CALL
:
1569 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1570 if (optimized_type
== tls::TLSOPT_NONE
)
1572 // Create a GOT entry for the module index.
1573 target
->got_mod_index_entry(symtab
, layout
, object
);
1575 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1576 unsupported_reloc_local(object
, r_type
);
1579 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1582 case elfcpp::R_386_TLS_IE
: // Initial-exec
1583 case elfcpp::R_386_TLS_IE_32
:
1584 case elfcpp::R_386_TLS_GOTIE
:
1585 layout
->set_has_static_tls();
1586 if (optimized_type
== tls::TLSOPT_NONE
)
1588 // For the R_386_TLS_IE relocation, we need to create a
1589 // dynamic relocation when building a shared library.
1590 if (r_type
== elfcpp::R_386_TLS_IE
1591 && parameters
->options().shared())
1593 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1595 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1596 rel_dyn
->add_local_relative(object
, r_sym
,
1597 elfcpp::R_386_RELATIVE
,
1598 output_section
, data_shndx
,
1599 reloc
.get_r_offset());
1601 // Create a GOT entry for the tp-relative offset.
1602 Output_data_got
<32, false>* got
1603 = target
->got_section(symtab
, layout
);
1604 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1605 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1606 ? elfcpp::R_386_TLS_TPOFF32
1607 : elfcpp::R_386_TLS_TPOFF
);
1608 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1609 ? GOT_TYPE_TLS_OFFSET
1610 : GOT_TYPE_TLS_NOFFSET
);
1611 got
->add_local_with_rel(object
, r_sym
, got_type
,
1612 target
->rel_dyn_section(layout
),
1615 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1616 unsupported_reloc_local(object
, r_type
);
1619 case elfcpp::R_386_TLS_LE
: // Local-exec
1620 case elfcpp::R_386_TLS_LE_32
:
1621 layout
->set_has_static_tls();
1622 if (output_is_shared
)
1624 // We need to create a dynamic relocation.
1625 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1626 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1627 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1628 ? elfcpp::R_386_TLS_TPOFF32
1629 : elfcpp::R_386_TLS_TPOFF
);
1630 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1631 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1632 data_shndx
, reloc
.get_r_offset());
1642 case elfcpp::R_386_32PLT
:
1643 case elfcpp::R_386_TLS_GD_32
:
1644 case elfcpp::R_386_TLS_GD_PUSH
:
1645 case elfcpp::R_386_TLS_GD_CALL
:
1646 case elfcpp::R_386_TLS_GD_POP
:
1647 case elfcpp::R_386_TLS_LDM_32
:
1648 case elfcpp::R_386_TLS_LDM_PUSH
:
1649 case elfcpp::R_386_TLS_LDM_CALL
:
1650 case elfcpp::R_386_TLS_LDM_POP
:
1651 case elfcpp::R_386_USED_BY_INTEL_200
:
1653 unsupported_reloc_local(object
, r_type
);
1658 // Report an unsupported relocation against a global symbol.
1661 Target_i386::Scan::unsupported_reloc_global(
1662 Sized_relobj_file
<32, false>* object
,
1663 unsigned int r_type
,
1666 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1667 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1671 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1675 case elfcpp::R_386_32
:
1676 case elfcpp::R_386_16
:
1677 case elfcpp::R_386_8
:
1678 case elfcpp::R_386_GOTOFF
:
1679 case elfcpp::R_386_GOT32
:
1690 Target_i386::Scan::local_reloc_may_be_function_pointer(
1694 Sized_relobj_file
<32, false>* ,
1697 const elfcpp::Rel
<32, false>& ,
1698 unsigned int r_type
,
1699 const elfcpp::Sym
<32, false>&)
1701 return possible_function_pointer_reloc(r_type
);
1705 Target_i386::Scan::global_reloc_may_be_function_pointer(
1709 Sized_relobj_file
<32, false>* ,
1712 const elfcpp::Rel
<32, false>& ,
1713 unsigned int r_type
,
1716 return possible_function_pointer_reloc(r_type
);
1719 // Scan a relocation for a global symbol.
1722 Target_i386::Scan::global(Symbol_table
* symtab
,
1724 Target_i386
* target
,
1725 Sized_relobj_file
<32, false>* object
,
1726 unsigned int data_shndx
,
1727 Output_section
* output_section
,
1728 const elfcpp::Rel
<32, false>& reloc
,
1729 unsigned int r_type
,
1732 // A STT_GNU_IFUNC symbol may require a PLT entry.
1733 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1734 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1735 target
->make_plt_entry(symtab
, layout
, gsym
);
1739 case elfcpp::R_386_NONE
:
1740 case elfcpp::R_386_GNU_VTINHERIT
:
1741 case elfcpp::R_386_GNU_VTENTRY
:
1744 case elfcpp::R_386_32
:
1745 case elfcpp::R_386_16
:
1746 case elfcpp::R_386_8
:
1748 // Make a PLT entry if necessary.
1749 if (gsym
->needs_plt_entry())
1751 target
->make_plt_entry(symtab
, layout
, gsym
);
1752 // Since this is not a PC-relative relocation, we may be
1753 // taking the address of a function. In that case we need to
1754 // set the entry in the dynamic symbol table to the address of
1756 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1757 gsym
->set_needs_dynsym_value();
1759 // Make a dynamic relocation if necessary.
1760 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
1762 if (gsym
->may_need_copy_reloc())
1764 target
->copy_reloc(symtab
, layout
, object
,
1765 data_shndx
, output_section
, gsym
, reloc
);
1767 else if (r_type
== elfcpp::R_386_32
1768 && gsym
->type() == elfcpp::STT_GNU_IFUNC
1769 && gsym
->can_use_relative_reloc(false)
1770 && !gsym
->is_from_dynobj()
1771 && !gsym
->is_undefined()
1772 && !gsym
->is_preemptible())
1774 // Use an IRELATIVE reloc for a locally defined
1775 // STT_GNU_IFUNC symbol. This makes a function
1776 // address in a PIE executable match the address in a
1777 // shared library that it links against.
1778 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1779 rel_dyn
->add_symbolless_global_addend(gsym
,
1780 elfcpp::R_386_IRELATIVE
,
1783 reloc
.get_r_offset());
1785 else if (r_type
== elfcpp::R_386_32
1786 && gsym
->can_use_relative_reloc(false))
1788 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1789 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1790 output_section
, object
,
1791 data_shndx
, reloc
.get_r_offset());
1795 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1796 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1797 data_shndx
, reloc
.get_r_offset());
1803 case elfcpp::R_386_PC32
:
1804 case elfcpp::R_386_PC16
:
1805 case elfcpp::R_386_PC8
:
1807 // Make a PLT entry if necessary.
1808 if (gsym
->needs_plt_entry())
1810 // These relocations are used for function calls only in
1811 // non-PIC code. For a 32-bit relocation in a shared library,
1812 // we'll need a text relocation anyway, so we can skip the
1813 // PLT entry and let the dynamic linker bind the call directly
1814 // to the target. For smaller relocations, we should use a
1815 // PLT entry to ensure that the call can reach.
1816 if (!parameters
->options().shared()
1817 || r_type
!= elfcpp::R_386_PC32
)
1818 target
->make_plt_entry(symtab
, layout
, gsym
);
1820 // Make a dynamic relocation if necessary.
1821 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
1823 if (gsym
->may_need_copy_reloc())
1825 target
->copy_reloc(symtab
, layout
, object
,
1826 data_shndx
, output_section
, gsym
, reloc
);
1830 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1831 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1832 data_shndx
, reloc
.get_r_offset());
1838 case elfcpp::R_386_GOT32
:
1840 // The symbol requires a GOT entry.
1841 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1842 if (gsym
->final_value_is_known())
1844 // For a STT_GNU_IFUNC symbol we want the PLT address.
1845 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1846 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1848 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1852 // If this symbol is not fully resolved, we need to add a
1853 // GOT entry with a dynamic relocation.
1854 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1855 if (gsym
->is_from_dynobj()
1856 || gsym
->is_undefined()
1857 || gsym
->is_preemptible()
1858 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
1859 && parameters
->options().output_is_position_independent()))
1860 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1861 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1864 // For a STT_GNU_IFUNC symbol we want to write the PLT
1865 // offset into the GOT, so that function pointer
1866 // comparisons work correctly.
1868 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
1869 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1872 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1873 // Tell the dynamic linker to use the PLT address
1874 // when resolving relocations.
1875 if (gsym
->is_from_dynobj()
1876 && !parameters
->options().shared())
1877 gsym
->set_needs_dynsym_value();
1881 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
1882 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1890 case elfcpp::R_386_PLT32
:
1891 // If the symbol is fully resolved, this is just a PC32 reloc.
1892 // Otherwise we need a PLT entry.
1893 if (gsym
->final_value_is_known())
1895 // If building a shared library, we can also skip the PLT entry
1896 // if the symbol is defined in the output file and is protected
1898 if (gsym
->is_defined()
1899 && !gsym
->is_from_dynobj()
1900 && !gsym
->is_preemptible())
1902 target
->make_plt_entry(symtab
, layout
, gsym
);
1905 case elfcpp::R_386_GOTOFF
:
1906 case elfcpp::R_386_GOTPC
:
1907 // We need a GOT section.
1908 target
->got_section(symtab
, layout
);
1911 // These are relocations which should only be seen by the
1912 // dynamic linker, and should never be seen here.
1913 case elfcpp::R_386_COPY
:
1914 case elfcpp::R_386_GLOB_DAT
:
1915 case elfcpp::R_386_JUMP_SLOT
:
1916 case elfcpp::R_386_RELATIVE
:
1917 case elfcpp::R_386_IRELATIVE
:
1918 case elfcpp::R_386_TLS_TPOFF
:
1919 case elfcpp::R_386_TLS_DTPMOD32
:
1920 case elfcpp::R_386_TLS_DTPOFF32
:
1921 case elfcpp::R_386_TLS_TPOFF32
:
1922 case elfcpp::R_386_TLS_DESC
:
1923 gold_error(_("%s: unexpected reloc %u in object file"),
1924 object
->name().c_str(), r_type
);
1927 // These are initial tls relocs, which are expected when
1929 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1930 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1931 case elfcpp::R_386_TLS_DESC_CALL
:
1932 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1933 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1934 case elfcpp::R_386_TLS_IE
: // Initial-exec
1935 case elfcpp::R_386_TLS_IE_32
:
1936 case elfcpp::R_386_TLS_GOTIE
:
1937 case elfcpp::R_386_TLS_LE
: // Local-exec
1938 case elfcpp::R_386_TLS_LE_32
:
1940 const bool is_final
= gsym
->final_value_is_known();
1941 const tls::Tls_optimization optimized_type
1942 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1945 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1946 if (optimized_type
== tls::TLSOPT_NONE
)
1948 // Create a pair of GOT entries for the module index and
1949 // dtv-relative offset.
1950 Output_data_got
<32, false>* got
1951 = target
->got_section(symtab
, layout
);
1952 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1953 target
->rel_dyn_section(layout
),
1954 elfcpp::R_386_TLS_DTPMOD32
,
1955 elfcpp::R_386_TLS_DTPOFF32
);
1957 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1959 // Create a GOT entry for the tp-relative offset.
1960 Output_data_got
<32, false>* got
1961 = target
->got_section(symtab
, layout
);
1962 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1963 target
->rel_dyn_section(layout
),
1964 elfcpp::R_386_TLS_TPOFF
);
1966 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1967 unsupported_reloc_global(object
, r_type
, gsym
);
1970 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1971 target
->define_tls_base_symbol(symtab
, layout
);
1972 if (optimized_type
== tls::TLSOPT_NONE
)
1974 // Create a double GOT entry with an R_386_TLS_DESC
1975 // reloc. The R_386_TLS_DESC reloc is resolved
1976 // lazily, so the GOT entry needs to be in an area in
1977 // .got.plt, not .got. Call got_section to make sure
1978 // the section has been created.
1979 target
->got_section(symtab
, layout
);
1980 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1981 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1982 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1983 elfcpp::R_386_TLS_DESC
, 0);
1985 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1987 // Create a GOT entry for the tp-relative offset.
1988 Output_data_got
<32, false>* got
1989 = target
->got_section(symtab
, layout
);
1990 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1991 target
->rel_dyn_section(layout
),
1992 elfcpp::R_386_TLS_TPOFF
);
1994 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1995 unsupported_reloc_global(object
, r_type
, gsym
);
1998 case elfcpp::R_386_TLS_DESC_CALL
:
2001 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2002 if (optimized_type
== tls::TLSOPT_NONE
)
2004 // Create a GOT entry for the module index.
2005 target
->got_mod_index_entry(symtab
, layout
, object
);
2007 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2008 unsupported_reloc_global(object
, r_type
, gsym
);
2011 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2014 case elfcpp::R_386_TLS_IE
: // Initial-exec
2015 case elfcpp::R_386_TLS_IE_32
:
2016 case elfcpp::R_386_TLS_GOTIE
:
2017 layout
->set_has_static_tls();
2018 if (optimized_type
== tls::TLSOPT_NONE
)
2020 // For the R_386_TLS_IE relocation, we need to create a
2021 // dynamic relocation when building a shared library.
2022 if (r_type
== elfcpp::R_386_TLS_IE
2023 && parameters
->options().shared())
2025 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2026 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2027 output_section
, object
,
2029 reloc
.get_r_offset());
2031 // Create a GOT entry for the tp-relative offset.
2032 Output_data_got
<32, false>* got
2033 = target
->got_section(symtab
, layout
);
2034 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2035 ? elfcpp::R_386_TLS_TPOFF32
2036 : elfcpp::R_386_TLS_TPOFF
);
2037 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2038 ? GOT_TYPE_TLS_OFFSET
2039 : GOT_TYPE_TLS_NOFFSET
);
2040 got
->add_global_with_rel(gsym
, got_type
,
2041 target
->rel_dyn_section(layout
),
2044 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2045 unsupported_reloc_global(object
, r_type
, gsym
);
2048 case elfcpp::R_386_TLS_LE
: // Local-exec
2049 case elfcpp::R_386_TLS_LE_32
:
2050 layout
->set_has_static_tls();
2051 if (parameters
->options().shared())
2053 // We need to create a dynamic relocation.
2054 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2055 ? elfcpp::R_386_TLS_TPOFF32
2056 : elfcpp::R_386_TLS_TPOFF
);
2057 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2058 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2059 data_shndx
, reloc
.get_r_offset());
2069 case elfcpp::R_386_32PLT
:
2070 case elfcpp::R_386_TLS_GD_32
:
2071 case elfcpp::R_386_TLS_GD_PUSH
:
2072 case elfcpp::R_386_TLS_GD_CALL
:
2073 case elfcpp::R_386_TLS_GD_POP
:
2074 case elfcpp::R_386_TLS_LDM_32
:
2075 case elfcpp::R_386_TLS_LDM_PUSH
:
2076 case elfcpp::R_386_TLS_LDM_CALL
:
2077 case elfcpp::R_386_TLS_LDM_POP
:
2078 case elfcpp::R_386_USED_BY_INTEL_200
:
2080 unsupported_reloc_global(object
, r_type
, gsym
);
2085 // Process relocations for gc.
2088 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2090 Sized_relobj_file
<32, false>* object
,
2091 unsigned int data_shndx
,
2093 const unsigned char* prelocs
,
2095 Output_section
* output_section
,
2096 bool needs_special_offset_handling
,
2097 size_t local_symbol_count
,
2098 const unsigned char* plocal_symbols
)
2100 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2102 Target_i386::Relocatable_size_for_reloc
>(
2111 needs_special_offset_handling
,
2116 // Scan relocations for a section.
2119 Target_i386::scan_relocs(Symbol_table
* symtab
,
2121 Sized_relobj_file
<32, false>* object
,
2122 unsigned int data_shndx
,
2123 unsigned int sh_type
,
2124 const unsigned char* prelocs
,
2126 Output_section
* output_section
,
2127 bool needs_special_offset_handling
,
2128 size_t local_symbol_count
,
2129 const unsigned char* plocal_symbols
)
2131 if (sh_type
== elfcpp::SHT_RELA
)
2133 gold_error(_("%s: unsupported RELA reloc section"),
2134 object
->name().c_str());
2138 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2148 needs_special_offset_handling
,
2153 // Finalize the sections.
2156 Target_i386::do_finalize_sections(
2158 const Input_objects
*,
2159 Symbol_table
* symtab
)
2161 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2163 : this->plt_
->rel_plt());
2164 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2165 this->rel_dyn_
, true, false);
2167 // Emit any relocs we saved in an attempt to avoid generating COPY
2169 if (this->copy_relocs_
.any_saved_relocs())
2170 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2172 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2173 // the .got.plt section.
2174 Symbol
* sym
= this->global_offset_table_
;
2177 uint32_t data_size
= this->got_plt_
->current_data_size();
2178 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2182 // Return whether a direct absolute static relocation needs to be applied.
2183 // In cases where Scan::local() or Scan::global() has created
2184 // a dynamic relocation other than R_386_RELATIVE, the addend
2185 // of the relocation is carried in the data, and we must not
2186 // apply the static relocation.
2189 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2190 unsigned int r_type
,
2192 Output_section
* output_section
)
2194 // If the output section is not allocated, then we didn't call
2195 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2197 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2200 int ref_flags
= Scan::get_reference_flags(r_type
);
2202 // For local symbols, we will have created a non-RELATIVE dynamic
2203 // relocation only if (a) the output is position independent,
2204 // (b) the relocation is absolute (not pc- or segment-relative), and
2205 // (c) the relocation is not 32 bits wide.
2207 return !(parameters
->options().output_is_position_independent()
2208 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2211 // For global symbols, we use the same helper routines used in the
2212 // scan pass. If we did not create a dynamic relocation, or if we
2213 // created a RELATIVE dynamic relocation, we should apply the static
2215 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2216 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2217 && gsym
->can_use_relative_reloc(ref_flags
2218 & Symbol::FUNCTION_CALL
);
2219 return !has_dyn
|| is_rel
;
2222 // Perform a relocation.
2225 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2226 Target_i386
* target
,
2227 Output_section
* output_section
,
2229 const elfcpp::Rel
<32, false>& rel
,
2230 unsigned int r_type
,
2231 const Sized_symbol
<32>* gsym
,
2232 const Symbol_value
<32>* psymval
,
2233 unsigned char* view
,
2234 elfcpp::Elf_types
<32>::Elf_Addr address
,
2235 section_size_type view_size
)
2237 if (this->skip_call_tls_get_addr_
)
2239 if ((r_type
!= elfcpp::R_386_PLT32
2240 && r_type
!= elfcpp::R_386_PC32
)
2242 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2243 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2244 _("missing expected TLS relocation"));
2247 this->skip_call_tls_get_addr_
= false;
2252 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2254 // Pick the value to use for symbols defined in shared objects.
2255 Symbol_value
<32> symval
;
2257 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2258 && r_type
== elfcpp::R_386_32
2259 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2260 && gsym
->can_use_relative_reloc(false)
2261 && !gsym
->is_from_dynobj()
2262 && !gsym
->is_undefined()
2263 && !gsym
->is_preemptible())
2265 // In this case we are generating a R_386_IRELATIVE reloc. We
2266 // want to use the real value of the symbol, not the PLT offset.
2268 else if (gsym
!= NULL
2269 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2271 symval
.set_output_value(target
->plt_section()->address()
2272 + gsym
->plt_offset());
2275 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2277 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2278 if (object
->local_has_plt_offset(r_sym
))
2280 symval
.set_output_value(target
->plt_section()->address()
2281 + object
->local_plt_offset(r_sym
));
2286 // Get the GOT offset if needed.
2287 // The GOT pointer points to the end of the GOT section.
2288 // We need to subtract the size of the GOT section to get
2289 // the actual offset to use in the relocation.
2290 bool have_got_offset
= false;
2291 unsigned int got_offset
= 0;
2294 case elfcpp::R_386_GOT32
:
2297 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2298 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2299 - target
->got_size());
2303 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2304 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2305 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2306 - target
->got_size());
2308 have_got_offset
= true;
2317 case elfcpp::R_386_NONE
:
2318 case elfcpp::R_386_GNU_VTINHERIT
:
2319 case elfcpp::R_386_GNU_VTENTRY
:
2322 case elfcpp::R_386_32
:
2323 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2324 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2327 case elfcpp::R_386_PC32
:
2328 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2329 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2332 case elfcpp::R_386_16
:
2333 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2334 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2337 case elfcpp::R_386_PC16
:
2338 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2339 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2342 case elfcpp::R_386_8
:
2343 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2344 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2347 case elfcpp::R_386_PC8
:
2348 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2349 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2352 case elfcpp::R_386_PLT32
:
2353 gold_assert(gsym
== NULL
2354 || gsym
->has_plt_offset()
2355 || gsym
->final_value_is_known()
2356 || (gsym
->is_defined()
2357 && !gsym
->is_from_dynobj()
2358 && !gsym
->is_preemptible()));
2359 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2362 case elfcpp::R_386_GOT32
:
2363 gold_assert(have_got_offset
);
2364 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2367 case elfcpp::R_386_GOTOFF
:
2369 elfcpp::Elf_types
<32>::Elf_Addr value
;
2370 value
= (psymval
->value(object
, 0)
2371 - target
->got_plt_section()->address());
2372 Relocate_functions
<32, false>::rel32(view
, value
);
2376 case elfcpp::R_386_GOTPC
:
2378 elfcpp::Elf_types
<32>::Elf_Addr value
;
2379 value
= target
->got_plt_section()->address();
2380 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2384 case elfcpp::R_386_COPY
:
2385 case elfcpp::R_386_GLOB_DAT
:
2386 case elfcpp::R_386_JUMP_SLOT
:
2387 case elfcpp::R_386_RELATIVE
:
2388 case elfcpp::R_386_IRELATIVE
:
2389 // These are outstanding tls relocs, which are unexpected when
2391 case elfcpp::R_386_TLS_TPOFF
:
2392 case elfcpp::R_386_TLS_DTPMOD32
:
2393 case elfcpp::R_386_TLS_DTPOFF32
:
2394 case elfcpp::R_386_TLS_TPOFF32
:
2395 case elfcpp::R_386_TLS_DESC
:
2396 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2397 _("unexpected reloc %u in object file"),
2401 // These are initial tls relocs, which are expected when
2403 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2404 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2405 case elfcpp::R_386_TLS_DESC_CALL
:
2406 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2407 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2408 case elfcpp::R_386_TLS_IE
: // Initial-exec
2409 case elfcpp::R_386_TLS_IE_32
:
2410 case elfcpp::R_386_TLS_GOTIE
:
2411 case elfcpp::R_386_TLS_LE
: // Local-exec
2412 case elfcpp::R_386_TLS_LE_32
:
2413 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2414 view
, address
, view_size
);
2417 case elfcpp::R_386_32PLT
:
2418 case elfcpp::R_386_TLS_GD_32
:
2419 case elfcpp::R_386_TLS_GD_PUSH
:
2420 case elfcpp::R_386_TLS_GD_CALL
:
2421 case elfcpp::R_386_TLS_GD_POP
:
2422 case elfcpp::R_386_TLS_LDM_32
:
2423 case elfcpp::R_386_TLS_LDM_PUSH
:
2424 case elfcpp::R_386_TLS_LDM_CALL
:
2425 case elfcpp::R_386_TLS_LDM_POP
:
2426 case elfcpp::R_386_USED_BY_INTEL_200
:
2428 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2429 _("unsupported reloc %u"),
2437 // Perform a TLS relocation.
2440 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2441 Target_i386
* target
,
2443 const elfcpp::Rel
<32, false>& rel
,
2444 unsigned int r_type
,
2445 const Sized_symbol
<32>* gsym
,
2446 const Symbol_value
<32>* psymval
,
2447 unsigned char* view
,
2448 elfcpp::Elf_types
<32>::Elf_Addr
,
2449 section_size_type view_size
)
2451 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2453 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2455 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2457 const bool is_final
= (gsym
== NULL
2458 ? !parameters
->options().shared()
2459 : gsym
->final_value_is_known());
2460 const tls::Tls_optimization optimized_type
2461 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2464 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2465 if (optimized_type
== tls::TLSOPT_TO_LE
)
2467 gold_assert(tls_segment
!= NULL
);
2468 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2469 rel
, r_type
, value
, view
,
2475 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2476 ? GOT_TYPE_TLS_NOFFSET
2477 : GOT_TYPE_TLS_PAIR
);
2478 unsigned int got_offset
;
2481 gold_assert(gsym
->has_got_offset(got_type
));
2482 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2486 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2487 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2488 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2489 - target
->got_size());
2491 if (optimized_type
== tls::TLSOPT_TO_IE
)
2493 gold_assert(tls_segment
!= NULL
);
2494 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2495 got_offset
, view
, view_size
);
2498 else if (optimized_type
== tls::TLSOPT_NONE
)
2500 // Relocate the field with the offset of the pair of GOT
2502 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2506 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2507 _("unsupported reloc %u"),
2511 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2512 case elfcpp::R_386_TLS_DESC_CALL
:
2513 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2514 if (optimized_type
== tls::TLSOPT_TO_LE
)
2516 gold_assert(tls_segment
!= NULL
);
2517 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2518 rel
, r_type
, value
, view
,
2524 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2525 ? GOT_TYPE_TLS_NOFFSET
2526 : GOT_TYPE_TLS_DESC
);
2527 unsigned int got_offset
= 0;
2528 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2529 && optimized_type
== tls::TLSOPT_NONE
)
2531 // We created GOT entries in the .got.tlsdesc portion of
2532 // the .got.plt section, but the offset stored in the
2533 // symbol is the offset within .got.tlsdesc.
2534 got_offset
= (target
->got_size()
2535 + target
->got_plt_section()->data_size());
2539 gold_assert(gsym
->has_got_offset(got_type
));
2540 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2544 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2545 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2546 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2547 - target
->got_size());
2549 if (optimized_type
== tls::TLSOPT_TO_IE
)
2551 gold_assert(tls_segment
!= NULL
);
2552 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2553 got_offset
, view
, view_size
);
2556 else if (optimized_type
== tls::TLSOPT_NONE
)
2558 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2560 // Relocate the field with the offset of the pair of GOT
2562 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2567 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2568 _("unsupported reloc %u"),
2572 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2573 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2575 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2576 _("both SUN and GNU model "
2577 "TLS relocations"));
2580 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2581 if (optimized_type
== tls::TLSOPT_TO_LE
)
2583 gold_assert(tls_segment
!= NULL
);
2584 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2585 value
, view
, view_size
);
2588 else if (optimized_type
== tls::TLSOPT_NONE
)
2590 // Relocate the field with the offset of the GOT entry for
2591 // the module index.
2592 unsigned int got_offset
;
2593 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2594 - 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_LDO_32
: // Alternate local-dynamic
2604 if (optimized_type
== tls::TLSOPT_TO_LE
)
2606 // This reloc can appear in debugging sections, in which
2607 // case we must not convert to local-exec. We decide what
2608 // to do based on whether the section is marked as
2609 // containing executable code. That is what the GNU linker
2611 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
2612 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
2614 gold_assert(tls_segment
!= NULL
);
2615 value
-= tls_segment
->memsz();
2618 Relocate_functions
<32, false>::rel32(view
, value
);
2621 case elfcpp::R_386_TLS_IE
: // Initial-exec
2622 case elfcpp::R_386_TLS_GOTIE
:
2623 case elfcpp::R_386_TLS_IE_32
:
2624 if (optimized_type
== tls::TLSOPT_TO_LE
)
2626 gold_assert(tls_segment
!= NULL
);
2627 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2628 rel
, r_type
, value
, view
,
2632 else if (optimized_type
== tls::TLSOPT_NONE
)
2634 // Relocate the field with the offset of the GOT entry for
2635 // the tp-relative offset of the symbol.
2636 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2637 ? GOT_TYPE_TLS_OFFSET
2638 : GOT_TYPE_TLS_NOFFSET
);
2639 unsigned int got_offset
;
2642 gold_assert(gsym
->has_got_offset(got_type
));
2643 got_offset
= gsym
->got_offset(got_type
);
2647 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2648 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2649 got_offset
= object
->local_got_offset(r_sym
, got_type
);
2651 // For the R_386_TLS_IE relocation, we need to apply the
2652 // absolute address of the GOT entry.
2653 if (r_type
== elfcpp::R_386_TLS_IE
)
2654 got_offset
+= target
->got_plt_section()->address();
2655 // All GOT offsets are relative to the end of the GOT.
2656 got_offset
-= target
->got_size();
2657 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2660 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2661 _("unsupported reloc %u"),
2665 case elfcpp::R_386_TLS_LE
: // Local-exec
2666 // If we're creating a shared library, a dynamic relocation will
2667 // have been created for this location, so do not apply it now.
2668 if (!parameters
->options().shared())
2670 gold_assert(tls_segment
!= NULL
);
2671 value
-= tls_segment
->memsz();
2672 Relocate_functions
<32, false>::rel32(view
, value
);
2676 case elfcpp::R_386_TLS_LE_32
:
2677 // If we're creating a shared library, a dynamic relocation will
2678 // have been created for this location, so do not apply it now.
2679 if (!parameters
->options().shared())
2681 gold_assert(tls_segment
!= NULL
);
2682 value
= tls_segment
->memsz() - value
;
2683 Relocate_functions
<32, false>::rel32(view
, value
);
2689 // Do a relocation in which we convert a TLS General-Dynamic to a
2693 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2695 Output_segment
* tls_segment
,
2696 const elfcpp::Rel
<32, false>& rel
,
2698 elfcpp::Elf_types
<32>::Elf_Addr value
,
2699 unsigned char* view
,
2700 section_size_type view_size
)
2702 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2703 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2704 // leal foo(%reg),%eax; call ___tls_get_addr
2705 // ==> movl %gs:0,%eax; subl $foo@tpoff,%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);
2721 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2722 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2723 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2724 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2725 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2729 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2730 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2731 if (rel
.get_r_offset() + 9 < view_size
2734 // There is a trailing nop. Use the size byte subl.
2735 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2740 // Use the five byte subl.
2741 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2745 value
= tls_segment
->memsz() - value
;
2746 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2748 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2750 this->skip_call_tls_get_addr_
= true;
2753 // Do a relocation in which we convert a TLS General-Dynamic to an
2757 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2760 const elfcpp::Rel
<32, false>& rel
,
2762 elfcpp::Elf_types
<32>::Elf_Addr value
,
2763 unsigned char* view
,
2764 section_size_type view_size
)
2766 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2767 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2769 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2770 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2772 unsigned char op1
= view
[-1];
2773 unsigned char op2
= view
[-2];
2775 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2776 op2
== 0x8d || op2
== 0x04);
2777 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2781 // FIXME: For now, support only the first (SIB) form.
2782 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2786 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2787 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2788 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2789 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2790 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2794 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2795 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2796 if (rel
.get_r_offset() + 9 < view_size
2799 // FIXME: This is not the right instruction sequence.
2800 // There is a trailing nop. Use the size byte subl.
2801 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2806 // FIXME: This is not the right instruction sequence.
2807 // Use the five byte subl.
2808 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2812 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2814 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2816 this->skip_call_tls_get_addr_
= true;
2819 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2820 // General-Dynamic to a Local-Exec.
2823 Target_i386::Relocate::tls_desc_gd_to_le(
2824 const Relocate_info
<32, false>* relinfo
,
2826 Output_segment
* tls_segment
,
2827 const elfcpp::Rel
<32, false>& rel
,
2828 unsigned int r_type
,
2829 elfcpp::Elf_types
<32>::Elf_Addr value
,
2830 unsigned char* view
,
2831 section_size_type view_size
)
2833 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2835 // leal foo@TLSDESC(%ebx), %eax
2836 // ==> leal foo@NTPOFF, %eax
2837 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2838 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2839 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2840 view
[-2] == 0x8d && view
[-1] == 0x83);
2842 value
-= tls_segment
->memsz();
2843 Relocate_functions
<32, false>::rel32(view
, value
);
2847 // call *foo@TLSCALL(%eax)
2849 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2850 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2851 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2852 view
[0] == 0xff && view
[1] == 0x10);
2858 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2859 // General-Dynamic to an Initial-Exec.
2862 Target_i386::Relocate::tls_desc_gd_to_ie(
2863 const Relocate_info
<32, false>* relinfo
,
2866 const elfcpp::Rel
<32, false>& rel
,
2867 unsigned int r_type
,
2868 elfcpp::Elf_types
<32>::Elf_Addr value
,
2869 unsigned char* view
,
2870 section_size_type view_size
)
2872 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2874 // leal foo@TLSDESC(%ebx), %eax
2875 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2876 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2877 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2878 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2879 view
[-2] == 0x8d && view
[-1] == 0x83);
2881 Relocate_functions
<32, false>::rel32(view
, value
);
2885 // call *foo@TLSCALL(%eax)
2887 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2888 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2889 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2890 view
[0] == 0xff && view
[1] == 0x10);
2896 // Do a relocation in which we convert a TLS Local-Dynamic to a
2900 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2903 const elfcpp::Rel
<32, false>& rel
,
2905 elfcpp::Elf_types
<32>::Elf_Addr
,
2906 unsigned char* view
,
2907 section_size_type view_size
)
2909 // leal foo(%reg), %eax; call ___tls_get_addr
2910 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2912 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2913 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2915 // FIXME: Does this test really always pass?
2916 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2917 view
[-2] == 0x8d && view
[-1] == 0x83);
2919 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2921 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2923 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2925 this->skip_call_tls_get_addr_
= true;
2928 // Do a relocation in which we convert a TLS Initial-Exec to a
2932 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2934 Output_segment
* tls_segment
,
2935 const elfcpp::Rel
<32, false>& rel
,
2936 unsigned int r_type
,
2937 elfcpp::Elf_types
<32>::Elf_Addr value
,
2938 unsigned char* view
,
2939 section_size_type view_size
)
2941 // We have to actually change the instructions, which means that we
2942 // need to examine the opcodes to figure out which instruction we
2944 if (r_type
== elfcpp::R_386_TLS_IE
)
2946 // movl %gs:XX,%eax ==> movl $YY,%eax
2947 // movl %gs:XX,%reg ==> movl $YY,%reg
2948 // addl %gs:XX,%reg ==> addl $YY,%reg
2949 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2950 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2952 unsigned char op1
= view
[-1];
2955 // movl XX,%eax ==> movl $YY,%eax
2960 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2962 unsigned char op2
= view
[-2];
2965 // movl XX,%reg ==> movl $YY,%reg
2966 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2967 (op1
& 0xc7) == 0x05);
2969 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2971 else if (op2
== 0x03)
2973 // addl XX,%reg ==> addl $YY,%reg
2974 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2975 (op1
& 0xc7) == 0x05);
2977 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2980 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2985 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2986 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2987 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2988 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2989 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2991 unsigned char op1
= view
[-1];
2992 unsigned char op2
= view
[-2];
2993 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2994 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2997 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2999 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3001 else if (op2
== 0x2b)
3003 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3005 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3007 else if (op2
== 0x03)
3009 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3011 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3014 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3017 value
= tls_segment
->memsz() - value
;
3018 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3021 Relocate_functions
<32, false>::rel32(view
, value
);
3024 // Relocate section data.
3027 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3028 unsigned int sh_type
,
3029 const unsigned char* prelocs
,
3031 Output_section
* output_section
,
3032 bool needs_special_offset_handling
,
3033 unsigned char* view
,
3034 elfcpp::Elf_types
<32>::Elf_Addr address
,
3035 section_size_type view_size
,
3036 const Reloc_symbol_changes
* reloc_symbol_changes
)
3038 gold_assert(sh_type
== elfcpp::SHT_REL
);
3040 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
3041 Target_i386::Relocate
>(
3047 needs_special_offset_handling
,
3051 reloc_symbol_changes
);
3054 // Return the size of a relocation while scanning during a relocatable
3058 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3059 unsigned int r_type
,
3064 case elfcpp::R_386_NONE
:
3065 case elfcpp::R_386_GNU_VTINHERIT
:
3066 case elfcpp::R_386_GNU_VTENTRY
:
3067 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3068 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3069 case elfcpp::R_386_TLS_DESC_CALL
:
3070 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3071 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3072 case elfcpp::R_386_TLS_IE
: // Initial-exec
3073 case elfcpp::R_386_TLS_IE_32
:
3074 case elfcpp::R_386_TLS_GOTIE
:
3075 case elfcpp::R_386_TLS_LE
: // Local-exec
3076 case elfcpp::R_386_TLS_LE_32
:
3079 case elfcpp::R_386_32
:
3080 case elfcpp::R_386_PC32
:
3081 case elfcpp::R_386_GOT32
:
3082 case elfcpp::R_386_PLT32
:
3083 case elfcpp::R_386_GOTOFF
:
3084 case elfcpp::R_386_GOTPC
:
3087 case elfcpp::R_386_16
:
3088 case elfcpp::R_386_PC16
:
3091 case elfcpp::R_386_8
:
3092 case elfcpp::R_386_PC8
:
3095 // These are relocations which should only be seen by the
3096 // dynamic linker, and should never be seen here.
3097 case elfcpp::R_386_COPY
:
3098 case elfcpp::R_386_GLOB_DAT
:
3099 case elfcpp::R_386_JUMP_SLOT
:
3100 case elfcpp::R_386_RELATIVE
:
3101 case elfcpp::R_386_IRELATIVE
:
3102 case elfcpp::R_386_TLS_TPOFF
:
3103 case elfcpp::R_386_TLS_DTPMOD32
:
3104 case elfcpp::R_386_TLS_DTPOFF32
:
3105 case elfcpp::R_386_TLS_TPOFF32
:
3106 case elfcpp::R_386_TLS_DESC
:
3107 object
->error(_("unexpected reloc %u in object file"), r_type
);
3110 case elfcpp::R_386_32PLT
:
3111 case elfcpp::R_386_TLS_GD_32
:
3112 case elfcpp::R_386_TLS_GD_PUSH
:
3113 case elfcpp::R_386_TLS_GD_CALL
:
3114 case elfcpp::R_386_TLS_GD_POP
:
3115 case elfcpp::R_386_TLS_LDM_32
:
3116 case elfcpp::R_386_TLS_LDM_PUSH
:
3117 case elfcpp::R_386_TLS_LDM_CALL
:
3118 case elfcpp::R_386_TLS_LDM_POP
:
3119 case elfcpp::R_386_USED_BY_INTEL_200
:
3121 object
->error(_("unsupported reloc %u in object file"), r_type
);
3126 // Scan the relocs during a relocatable link.
3129 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3131 Sized_relobj_file
<32, false>* object
,
3132 unsigned int data_shndx
,
3133 unsigned int sh_type
,
3134 const unsigned char* prelocs
,
3136 Output_section
* output_section
,
3137 bool needs_special_offset_handling
,
3138 size_t local_symbol_count
,
3139 const unsigned char* plocal_symbols
,
3140 Relocatable_relocs
* rr
)
3142 gold_assert(sh_type
== elfcpp::SHT_REL
);
3144 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3145 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3147 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3148 Scan_relocatable_relocs
>(
3156 needs_special_offset_handling
,
3162 // Relocate a section during a relocatable link.
3165 Target_i386::relocate_for_relocatable(
3166 const Relocate_info
<32, false>* relinfo
,
3167 unsigned int sh_type
,
3168 const unsigned char* prelocs
,
3170 Output_section
* output_section
,
3171 off_t offset_in_output_section
,
3172 const Relocatable_relocs
* rr
,
3173 unsigned char* view
,
3174 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3175 section_size_type view_size
,
3176 unsigned char* reloc_view
,
3177 section_size_type reloc_view_size
)
3179 gold_assert(sh_type
== elfcpp::SHT_REL
);
3181 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
3186 offset_in_output_section
,
3195 // Return the value to use for a dynamic which requires special
3196 // treatment. This is how we support equality comparisons of function
3197 // pointers across shared library boundaries, as described in the
3198 // processor specific ABI supplement.
3201 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3203 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3204 return this->plt_section()->address() + gsym
->plt_offset();
3207 // Return a string used to fill a code section with nops to take up
3208 // the specified length.
3211 Target_i386::do_code_fill(section_size_type length
) const
3215 // Build a jmp instruction to skip over the bytes.
3216 unsigned char jmp
[5];
3218 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3219 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3220 + std::string(length
- 5, '\0'));
3223 // Nop sequences of various lengths.
3224 const char nop1
[1] = { 0x90 }; // nop
3225 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
3226 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
3227 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
3228 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
3229 0x00 }; // leal 0(%esi,1),%esi
3230 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3232 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3234 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
3235 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3236 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
3237 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
3239 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3240 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3242 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3243 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3245 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3246 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3247 0x00, 0x00, 0x00, 0x00 };
3248 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3249 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3250 0x27, 0x00, 0x00, 0x00,
3252 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3253 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3254 0xbc, 0x27, 0x00, 0x00,
3256 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3257 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3258 0x90, 0x90, 0x90, 0x90,
3261 const char* nops
[16] = {
3263 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3264 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3267 return std::string(nops
[length
], length
);
3270 // Return whether SYM should be treated as a call to a non-split
3271 // function. We don't want that to be true of a call to a
3272 // get_pc_thunk function.
3275 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3277 return (sym
->type() == elfcpp::STT_FUNC
3278 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3281 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3282 // compiled with -fsplit-stack. The function calls non-split-stack
3283 // code. We have to change the function so that it always ensures
3284 // that it has enough stack space to run some random function.
3287 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3288 section_offset_type fnoffset
,
3289 section_size_type fnsize
,
3290 unsigned char* view
,
3291 section_size_type view_size
,
3293 std::string
* to
) const
3295 // The function starts with a comparison of the stack pointer and a
3296 // field in the TCB. This is followed by a jump.
3299 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3302 // We will call __morestack if the carry flag is set after this
3303 // comparison. We turn the comparison into an stc instruction
3305 view
[fnoffset
] = '\xf9';
3306 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3308 // lea NN(%esp),%ecx
3309 // lea NN(%esp),%edx
3310 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3311 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3314 // This is loading an offset from the stack pointer for a
3315 // comparison. The offset is negative, so we decrease the
3316 // offset by the amount of space we need for the stack. This
3317 // means we will avoid calling __morestack if there happens to
3318 // be plenty of space on the stack already.
3319 unsigned char* pval
= view
+ fnoffset
+ 3;
3320 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3321 val
-= parameters
->options().split_stack_adjust_size();
3322 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3326 if (!object
->has_no_split_stack())
3327 object
->error(_("failed to match split-stack sequence at "
3328 "section %u offset %0zx"),
3329 shndx
, static_cast<size_t>(fnoffset
));
3333 // We have to change the function so that it calls
3334 // __morestack_non_split instead of __morestack. The former will
3335 // allocate additional stack space.
3336 *from
= "__morestack";
3337 *to
= "__morestack_non_split";
3340 // The selector for i386 object files.
3342 class Target_selector_i386
: public Target_selector_freebsd
3345 Target_selector_i386()
3346 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3347 "elf32-i386", "elf32-i386-freebsd",
3352 do_instantiate_target()
3353 { return new Target_i386(); }
3356 Target_selector_i386 target_selector_i386
;
3358 } // End anonymous namespace.