1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
28 #include "parameters.h"
35 #include "copy-relocs.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
48 // A class to handle the PLT data.
50 class Output_data_plt_i386
: public Output_section_data
53 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
55 Output_data_plt_i386(Symbol_table
*, Layout
*, Output_data_space
*);
57 // Add an entry to the PLT.
59 add_entry(Symbol
* gsym
);
61 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
63 add_local_ifunc_entry(Sized_relobj
<32, false>* relobj
,
64 unsigned int local_sym_index
);
66 // Return the .rel.plt section data.
69 { return this->rel_
; }
71 // Return where the TLS_DESC relocations should go.
73 rel_tls_desc(Layout
*);
75 // Return the number of PLT entries.
78 { return this->count_
; }
80 // Return the offset of the first non-reserved PLT entry.
82 first_plt_entry_offset()
83 { return plt_entry_size
; }
85 // Return the size of a PLT entry.
88 { return plt_entry_size
; }
92 do_adjust_output_section(Output_section
* os
);
94 // Write to a map file.
96 do_print_to_mapfile(Mapfile
* mapfile
) const
97 { mapfile
->print_output_data(this, _("** PLT")); }
100 // The size of an entry in the PLT.
101 static const int plt_entry_size
= 16;
103 // The first entry in the PLT for an executable.
104 static unsigned char exec_first_plt_entry
[plt_entry_size
];
106 // The first entry in the PLT for a shared object.
107 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
109 // Other entries in the PLT for an executable.
110 static unsigned char exec_plt_entry
[plt_entry_size
];
112 // Other entries in the PLT for a shared object.
113 static unsigned char dyn_plt_entry
[plt_entry_size
];
115 // Set the final size.
117 set_final_data_size()
118 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
120 // Write out the PLT data.
122 do_write(Output_file
*);
124 // We keep a list of global STT_GNU_IFUNC symbols, each with its
125 // offset in the GOT.
129 unsigned int got_offset
;
132 // We keep a list of local STT_GNU_IFUNC symbols, each with its
133 // offset in the GOT.
136 Sized_relobj
<32, false>* object
;
137 unsigned int local_sym_index
;
138 unsigned int got_offset
;
141 // The reloc section.
143 // The TLS_DESC relocations, if necessary. These must follow the
144 // regular PLT relocs.
145 Reloc_section
* tls_desc_rel_
;
146 // The .got.plt section.
147 Output_data_space
* got_plt_
;
148 // The number of PLT entries.
150 // Global STT_GNU_IFUNC symbols.
151 std::vector
<Global_ifunc
> global_ifuncs_
;
152 // Local STT_GNU_IFUNC symbols.
153 std::vector
<Local_ifunc
> local_ifuncs_
;
156 // The i386 target class.
157 // TLS info comes from
158 // http://people.redhat.com/drepper/tls.pdf
159 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
161 class Target_i386
: public Target_freebsd
<32, false>
164 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
167 : Target_freebsd
<32, false>(&i386_info
),
168 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_tlsdesc_(NULL
),
169 global_offset_table_(NULL
), rel_dyn_(NULL
),
170 copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
171 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
175 can_check_for_function_pointers() const
178 // Process the relocations to determine unreferenced sections for
179 // garbage collection.
181 gc_process_relocs(Symbol_table
* symtab
,
183 Sized_relobj
<32, false>* object
,
184 unsigned int data_shndx
,
185 unsigned int sh_type
,
186 const unsigned char* prelocs
,
188 Output_section
* output_section
,
189 bool needs_special_offset_handling
,
190 size_t local_symbol_count
,
191 const unsigned char* plocal_symbols
);
193 // Scan the relocations to look for symbol adjustments.
195 scan_relocs(Symbol_table
* symtab
,
197 Sized_relobj
<32, false>* object
,
198 unsigned int data_shndx
,
199 unsigned int sh_type
,
200 const unsigned char* prelocs
,
202 Output_section
* output_section
,
203 bool needs_special_offset_handling
,
204 size_t local_symbol_count
,
205 const unsigned char* plocal_symbols
);
207 // Finalize the sections.
209 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
211 // Return the value to use for a dynamic which requires special
214 do_dynsym_value(const Symbol
*) const;
216 // Relocate a section.
218 relocate_section(const Relocate_info
<32, false>*,
219 unsigned int sh_type
,
220 const unsigned char* prelocs
,
222 Output_section
* output_section
,
223 bool needs_special_offset_handling
,
225 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
226 section_size_type view_size
,
227 const Reloc_symbol_changes
*);
229 // Scan the relocs during a relocatable link.
231 scan_relocatable_relocs(Symbol_table
* symtab
,
233 Sized_relobj
<32, false>* object
,
234 unsigned int data_shndx
,
235 unsigned int sh_type
,
236 const unsigned char* prelocs
,
238 Output_section
* output_section
,
239 bool needs_special_offset_handling
,
240 size_t local_symbol_count
,
241 const unsigned char* plocal_symbols
,
242 Relocatable_relocs
*);
244 // Relocate a section during a relocatable link.
246 relocate_for_relocatable(const Relocate_info
<32, false>*,
247 unsigned int sh_type
,
248 const unsigned char* prelocs
,
250 Output_section
* output_section
,
251 off_t offset_in_output_section
,
252 const Relocatable_relocs
*,
254 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
255 section_size_type view_size
,
256 unsigned char* reloc_view
,
257 section_size_type reloc_view_size
);
259 // Return a string used to fill a code section with nops.
261 do_code_fill(section_size_type length
) const;
263 // Return whether SYM is defined by the ABI.
265 do_is_defined_by_abi(const Symbol
* sym
) const
266 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
268 // Return whether a symbol name implies a local label. The UnixWare
269 // 2.1 cc generates temporary symbols that start with .X, so we
270 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
271 // If so, we should move the .X recognition into
272 // Target::do_is_local_label_name.
274 do_is_local_label_name(const char* name
) const
276 if (name
[0] == '.' && name
[1] == 'X')
278 return Target::do_is_local_label_name(name
);
281 // Return the PLT section.
283 do_plt_section_for_global(const Symbol
*) const
284 { return this->plt_section(); }
287 do_plt_section_for_local(const Relobj
*, unsigned int) const
288 { return this->plt_section(); }
290 // Return whether SYM is call to a non-split function.
292 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
294 // Adjust -fstack-split code which calls non-stack-split code.
296 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
297 section_offset_type fnoffset
, section_size_type fnsize
,
298 unsigned char* view
, section_size_type view_size
,
299 std::string
* from
, std::string
* to
) const;
301 // Return the size of the GOT section.
305 gold_assert(this->got_
!= NULL
);
306 return this->got_
->data_size();
309 // Return the number of entries in the GOT.
311 got_entry_count() const
313 if (this->got_
== NULL
)
315 return this->got_size() / 4;
318 // Return the number of entries in the PLT.
320 plt_entry_count() const;
322 // Return the offset of the first non-reserved PLT entry.
324 first_plt_entry_offset() const;
326 // Return the size of each PLT entry.
328 plt_entry_size() const;
331 // The class which scans relocations.
335 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
336 Sized_relobj
<32, false>* object
,
337 unsigned int data_shndx
,
338 Output_section
* output_section
,
339 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
340 const elfcpp::Sym
<32, false>& lsym
);
343 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
344 Sized_relobj
<32, false>* object
,
345 unsigned int data_shndx
,
346 Output_section
* output_section
,
347 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
351 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
353 Sized_relobj
<32, false>* object
,
354 unsigned int data_shndx
,
355 Output_section
* output_section
,
356 const elfcpp::Rel
<32, false>& reloc
,
358 const elfcpp::Sym
<32, false>& lsym
);
361 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
363 Sized_relobj
<32, false>* object
,
364 unsigned int data_shndx
,
365 Output_section
* output_section
,
366 const elfcpp::Rel
<32, false>& reloc
,
371 possible_function_pointer_reloc(unsigned int r_type
);
374 reloc_needs_plt_for_ifunc(Sized_relobj
<32, false>*, unsigned int r_type
);
377 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
380 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
384 // The class which implements relocation.
389 : skip_call_tls_get_addr_(false),
390 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
395 if (this->skip_call_tls_get_addr_
)
397 // FIXME: This needs to specify the location somehow.
398 gold_error(_("missing expected TLS relocation"));
402 // Return whether the static relocation needs to be applied.
404 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
407 Output_section
* output_section
);
409 // Do a relocation. Return false if the caller should not issue
410 // any warnings about this relocation.
412 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
413 size_t relnum
, const elfcpp::Rel
<32, false>&,
414 unsigned int r_type
, const Sized_symbol
<32>*,
415 const Symbol_value
<32>*,
416 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
420 // Do a TLS relocation.
422 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
423 size_t relnum
, const elfcpp::Rel
<32, false>&,
424 unsigned int r_type
, const Sized_symbol
<32>*,
425 const Symbol_value
<32>*,
426 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
429 // Do a TLS General-Dynamic to Initial-Exec transition.
431 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
432 Output_segment
* tls_segment
,
433 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
434 elfcpp::Elf_types
<32>::Elf_Addr value
,
436 section_size_type view_size
);
438 // Do a TLS General-Dynamic to Local-Exec transition.
440 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
441 Output_segment
* tls_segment
,
442 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
443 elfcpp::Elf_types
<32>::Elf_Addr value
,
445 section_size_type view_size
);
447 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
450 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
451 Output_segment
* tls_segment
,
452 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
453 elfcpp::Elf_types
<32>::Elf_Addr value
,
455 section_size_type view_size
);
457 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
460 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
461 Output_segment
* tls_segment
,
462 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
463 elfcpp::Elf_types
<32>::Elf_Addr value
,
465 section_size_type view_size
);
467 // Do a TLS Local-Dynamic to Local-Exec transition.
469 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
470 Output_segment
* tls_segment
,
471 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
472 elfcpp::Elf_types
<32>::Elf_Addr value
,
474 section_size_type view_size
);
476 // Do a TLS Initial-Exec to Local-Exec transition.
478 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
479 Output_segment
* tls_segment
,
480 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
481 elfcpp::Elf_types
<32>::Elf_Addr value
,
483 section_size_type view_size
);
485 // We need to keep track of which type of local dynamic relocation
486 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
487 enum Local_dynamic_type
494 // This is set if we should skip the next reloc, which should be a
495 // PLT32 reloc against ___tls_get_addr.
496 bool skip_call_tls_get_addr_
;
497 // The type of local dynamic relocation we have seen in the section
498 // being relocated, if any.
499 Local_dynamic_type local_dynamic_type_
;
502 // A class which returns the size required for a relocation type,
503 // used while scanning relocs during a relocatable link.
504 class Relocatable_size_for_reloc
508 get_size_for_reloc(unsigned int, Relobj
*);
511 // Adjust TLS relocation type based on the options and whether this
512 // is a local symbol.
513 static tls::Tls_optimization
514 optimize_tls_reloc(bool is_final
, int r_type
);
516 // Get the GOT section, creating it if necessary.
517 Output_data_got
<32, false>*
518 got_section(Symbol_table
*, Layout
*);
520 // Get the GOT PLT section.
522 got_plt_section() const
524 gold_assert(this->got_plt_
!= NULL
);
525 return this->got_plt_
;
528 // Get the GOT section for TLSDESC entries.
529 Output_data_got
<32, false>*
530 got_tlsdesc_section() const
532 gold_assert(this->got_tlsdesc_
!= NULL
);
533 return this->got_tlsdesc_
;
536 // Create the PLT section.
538 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
540 // Create a PLT entry for a global symbol.
542 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
544 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
546 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
547 Sized_relobj
<32, false>* relobj
,
548 unsigned int local_sym_index
);
550 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
552 define_tls_base_symbol(Symbol_table
*, Layout
*);
554 // Create a GOT entry for the TLS module index.
556 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
557 Sized_relobj
<32, false>* object
);
559 // Get the PLT section.
560 Output_data_plt_i386
*
563 gold_assert(this->plt_
!= NULL
);
567 // Get the dynamic reloc section, creating it if necessary.
569 rel_dyn_section(Layout
*);
571 // Get the section to use for TLS_DESC relocations.
573 rel_tls_desc_section(Layout
*) const;
575 // Add a potential copy relocation.
577 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
578 Sized_relobj
<32, false>* object
,
579 unsigned int shndx
, Output_section
* output_section
,
580 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
582 this->copy_relocs_
.copy_reloc(symtab
, layout
,
583 symtab
->get_sized_symbol
<32>(sym
),
584 object
, shndx
, output_section
, reloc
,
585 this->rel_dyn_section(layout
));
588 // Information about this specific target which we pass to the
589 // general Target structure.
590 static const Target::Target_info i386_info
;
592 // The types of GOT entries needed for this platform.
593 // These values are exposed to the ABI in an incremental link.
594 // Do not renumber existing values without changing the version
595 // number of the .gnu_incremental_inputs section.
598 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
599 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
600 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
601 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
602 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
606 Output_data_got
<32, false>* got_
;
608 Output_data_plt_i386
* plt_
;
609 // The GOT PLT section.
610 Output_data_space
* got_plt_
;
611 // The GOT section for TLSDESC relocations.
612 Output_data_got
<32, false>* got_tlsdesc_
;
613 // The _GLOBAL_OFFSET_TABLE_ symbol.
614 Symbol
* global_offset_table_
;
615 // The dynamic reloc section.
616 Reloc_section
* rel_dyn_
;
617 // Relocs saved to avoid a COPY reloc.
618 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
619 // Space for variables copied with a COPY reloc.
620 Output_data_space
* dynbss_
;
621 // Offset of the GOT entry for the TLS module index.
622 unsigned int got_mod_index_offset_
;
623 // True if the _TLS_MODULE_BASE_ symbol has been defined.
624 bool tls_base_symbol_defined_
;
627 const Target::Target_info
Target_i386::i386_info
=
630 false, // is_big_endian
631 elfcpp::EM_386
, // machine_code
632 false, // has_make_symbol
633 false, // has_resolve
634 true, // has_code_fill
635 true, // is_default_stack_executable
637 "/usr/lib/libc.so.1", // dynamic_linker
638 0x08048000, // default_text_segment_address
639 0x1000, // abi_pagesize (overridable by -z max-page-size)
640 0x1000, // common_pagesize (overridable by -z common-page-size)
641 elfcpp::SHN_UNDEF
, // small_common_shndx
642 elfcpp::SHN_UNDEF
, // large_common_shndx
643 0, // small_common_section_flags
644 0, // large_common_section_flags
645 NULL
, // attributes_section
646 NULL
// attributes_vendor
649 // Get the GOT section, creating it if necessary.
651 Output_data_got
<32, false>*
652 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
654 if (this->got_
== NULL
)
656 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
658 this->got_
= new Output_data_got
<32, false>();
660 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
662 | elfcpp::SHF_WRITE
),
663 this->got_
, ORDER_RELRO_LAST
, true);
665 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
666 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
668 | elfcpp::SHF_WRITE
),
669 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
672 // The first three entries are reserved.
673 this->got_plt_
->set_current_data_size(3 * 4);
675 // Those bytes can go into the relro segment.
676 layout
->increase_relro(3 * 4);
678 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
679 this->global_offset_table_
=
680 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
681 Symbol_table::PREDEFINED
,
683 0, 0, elfcpp::STT_OBJECT
,
685 elfcpp::STV_HIDDEN
, 0,
688 // If there are any TLSDESC relocations, they get GOT entries in
689 // .got.plt after the jump slot entries.
690 this->got_tlsdesc_
= new Output_data_got
<32, false>();
691 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
693 | elfcpp::SHF_WRITE
),
695 ORDER_NON_RELRO_FIRST
, false);
701 // Get the dynamic reloc section, creating it if necessary.
703 Target_i386::Reloc_section
*
704 Target_i386::rel_dyn_section(Layout
* layout
)
706 if (this->rel_dyn_
== NULL
)
708 gold_assert(layout
!= NULL
);
709 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
710 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
711 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
712 ORDER_DYNAMIC_RELOCS
, false);
714 return this->rel_dyn_
;
717 // Create the PLT section. The ordinary .got section is an argument,
718 // since we need to refer to the start. We also create our own .got
719 // section just for PLT entries.
721 Output_data_plt_i386::Output_data_plt_i386(Symbol_table
* symtab
,
723 Output_data_space
* got_plt
)
724 : Output_section_data(4), tls_desc_rel_(NULL
), got_plt_(got_plt
), count_(0),
725 global_ifuncs_(), local_ifuncs_()
727 this->rel_
= new Reloc_section(false);
728 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
729 elfcpp::SHF_ALLOC
, this->rel_
,
730 ORDER_DYNAMIC_PLT_RELOCS
, false);
732 if (parameters
->doing_static_link())
734 // A statically linked executable will only have a .rel.plt
735 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
736 // symbols. The library will use these symbols to locate the
737 // IRELATIVE relocs at program startup time.
738 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
739 Symbol_table::PREDEFINED
,
740 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
741 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
743 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
744 Symbol_table::PREDEFINED
,
745 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
746 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
752 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
754 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
755 // linker, and so do we.
759 // Add an entry to the PLT.
762 Output_data_plt_i386::add_entry(Symbol
* gsym
)
764 gold_assert(!gsym
->has_plt_offset());
766 // Note that when setting the PLT offset we skip the initial
767 // reserved PLT entry.
768 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
772 section_offset_type got_offset
= this->got_plt_
->current_data_size();
774 // Every PLT entry needs a GOT entry which points back to the PLT
775 // entry (this will be changed by the dynamic linker, normally
776 // lazily when the function is called).
777 this->got_plt_
->set_current_data_size(got_offset
+ 4);
779 // Every PLT entry needs a reloc.
780 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
781 && gsym
->can_use_relative_reloc(false))
783 this->rel_
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
784 this->got_plt_
, got_offset
);
785 struct Global_ifunc gi
;
787 gi
.got_offset
= got_offset
;
788 this->global_ifuncs_
.push_back(gi
);
792 gsym
->set_needs_dynsym_entry();
793 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
797 // Note that we don't need to save the symbol. The contents of the
798 // PLT are independent of which symbols are used. The symbols only
799 // appear in the relocations.
802 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
806 Output_data_plt_i386::add_local_ifunc_entry(Sized_relobj
<32, false>* relobj
,
807 unsigned int local_sym_index
)
809 unsigned int plt_offset
= (this->count_
+ 1) * plt_entry_size
;
812 section_offset_type got_offset
= this->got_plt_
->current_data_size();
814 // Every PLT entry needs a GOT entry which points back to the PLT
816 this->got_plt_
->set_current_data_size(got_offset
+ 4);
818 // Every PLT entry needs a reloc.
819 this->rel_
->add_symbolless_local_addend(relobj
, local_sym_index
,
820 elfcpp::R_386_IRELATIVE
,
821 this->got_plt_
, got_offset
);
823 struct Local_ifunc li
;
825 li
.local_sym_index
= local_sym_index
;
826 li
.got_offset
= got_offset
;
827 this->local_ifuncs_
.push_back(li
);
832 // Return where the TLS_DESC relocations should go, creating it if
833 // necessary. These follow the JUMP_SLOT relocations.
835 Output_data_plt_i386::Reloc_section
*
836 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
838 if (this->tls_desc_rel_
== NULL
)
840 this->tls_desc_rel_
= new Reloc_section(false);
841 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
842 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
843 ORDER_DYNAMIC_PLT_RELOCS
, false);
844 gold_assert(this->tls_desc_rel_
->output_section() ==
845 this->rel_
->output_section());
847 return this->tls_desc_rel_
;
850 // The first entry in the PLT for an executable.
852 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
854 0xff, 0x35, // pushl contents of memory address
855 0, 0, 0, 0, // replaced with address of .got + 4
856 0xff, 0x25, // jmp indirect
857 0, 0, 0, 0, // replaced with address of .got + 8
861 // The first entry in the PLT for a shared object.
863 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
865 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
866 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
870 // Subsequent entries in the PLT for an executable.
872 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
874 0xff, 0x25, // jmp indirect
875 0, 0, 0, 0, // replaced with address of symbol in .got
876 0x68, // pushl immediate
877 0, 0, 0, 0, // replaced with offset into relocation table
878 0xe9, // jmp relative
879 0, 0, 0, 0 // replaced with offset to start of .plt
882 // Subsequent entries in the PLT for a shared object.
884 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
886 0xff, 0xa3, // jmp *offset(%ebx)
887 0, 0, 0, 0, // replaced with offset of symbol in .got
888 0x68, // pushl immediate
889 0, 0, 0, 0, // replaced with offset into relocation table
890 0xe9, // jmp relative
891 0, 0, 0, 0 // replaced with offset to start of .plt
894 // Write out the PLT. This uses the hand-coded instructions above,
895 // and adjusts them as needed. This is all specified by the i386 ELF
896 // Processor Supplement.
899 Output_data_plt_i386::do_write(Output_file
* of
)
901 const off_t offset
= this->offset();
902 const section_size_type oview_size
=
903 convert_to_section_size_type(this->data_size());
904 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
906 const off_t got_file_offset
= this->got_plt_
->offset();
907 const section_size_type got_size
=
908 convert_to_section_size_type(this->got_plt_
->data_size());
909 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
912 unsigned char* pov
= oview
;
914 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
915 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
917 if (parameters
->options().output_is_position_independent())
918 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
921 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
922 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
923 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
925 pov
+= plt_entry_size
;
927 unsigned char* got_pov
= got_view
;
929 memset(got_pov
, 0, 12);
932 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
934 unsigned int plt_offset
= plt_entry_size
;
935 unsigned int plt_rel_offset
= 0;
936 unsigned int got_offset
= 12;
937 const unsigned int count
= this->count_
;
938 for (unsigned int i
= 0;
941 pov
+= plt_entry_size
,
943 plt_offset
+= plt_entry_size
,
944 plt_rel_offset
+= rel_size
,
947 // Set and adjust the PLT entry itself.
949 if (parameters
->options().output_is_position_independent())
951 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
952 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
956 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
957 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
962 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
963 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
964 - (plt_offset
+ plt_entry_size
));
966 // Set the entry in the GOT.
967 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
970 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
971 // the GOT to point to the actual symbol value, rather than point to
972 // the PLT entry. That will let the dynamic linker call the right
973 // function when resolving IRELATIVE relocations.
974 for (std::vector
<Global_ifunc
>::const_iterator p
=
975 this->global_ifuncs_
.begin();
976 p
!= this->global_ifuncs_
.end();
979 const Sized_symbol
<32>* ssym
=
980 static_cast<const Sized_symbol
<32>*>(p
->sym
);
981 elfcpp::Swap
<32, false>::writeval(got_view
+ p
->got_offset
,
985 for (std::vector
<Local_ifunc
>::const_iterator p
=
986 this->local_ifuncs_
.begin();
987 p
!= this->local_ifuncs_
.end();
990 const Symbol_value
<32>* psymval
=
991 p
->object
->local_symbol(p
->local_sym_index
);
992 elfcpp::Swap
<32, false>::writeval(got_view
+ p
->got_offset
,
993 psymval
->value(p
->object
, 0));
996 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
997 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
999 of
->write_output_view(offset
, oview_size
, oview
);
1000 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1003 // Create the PLT section.
1006 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1008 if (this->plt_
== NULL
)
1010 // Create the GOT sections first.
1011 this->got_section(symtab
, layout
);
1013 this->plt_
= new Output_data_plt_i386(symtab
, layout
, this->got_plt_
);
1014 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1016 | elfcpp::SHF_EXECINSTR
),
1017 this->plt_
, ORDER_PLT
, false);
1019 // Make the sh_info field of .rel.plt point to .plt.
1020 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1021 rel_plt_os
->set_info_section(this->plt_
->output_section());
1025 // Create a PLT entry for a global symbol.
1028 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1030 if (gsym
->has_plt_offset())
1032 if (this->plt_
== NULL
)
1033 this->make_plt_section(symtab
, layout
);
1034 this->plt_
->add_entry(gsym
);
1037 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1040 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1041 Sized_relobj
<32, false>* relobj
,
1042 unsigned int local_sym_index
)
1044 if (relobj
->local_has_plt_offset(local_sym_index
))
1046 if (this->plt_
== NULL
)
1047 this->make_plt_section(symtab
, layout
);
1048 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(relobj
,
1050 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1053 // Return the number of entries in the PLT.
1056 Target_i386::plt_entry_count() const
1058 if (this->plt_
== NULL
)
1060 return this->plt_
->entry_count();
1063 // Return the offset of the first non-reserved PLT entry.
1066 Target_i386::first_plt_entry_offset() const
1068 return Output_data_plt_i386::first_plt_entry_offset();
1071 // Return the size of each PLT entry.
1074 Target_i386::plt_entry_size() const
1076 return Output_data_plt_i386::get_plt_entry_size();
1079 // Get the section to use for TLS_DESC relocations.
1081 Target_i386::Reloc_section
*
1082 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1084 return this->plt_section()->rel_tls_desc(layout
);
1087 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1090 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1092 if (this->tls_base_symbol_defined_
)
1095 Output_segment
* tls_segment
= layout
->tls_segment();
1096 if (tls_segment
!= NULL
)
1098 bool is_exec
= parameters
->options().output_is_executable();
1099 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1100 Symbol_table::PREDEFINED
,
1104 elfcpp::STV_HIDDEN
, 0,
1106 ? Symbol::SEGMENT_END
1107 : Symbol::SEGMENT_START
),
1110 this->tls_base_symbol_defined_
= true;
1113 // Create a GOT entry for the TLS module index.
1116 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1117 Sized_relobj
<32, false>* object
)
1119 if (this->got_mod_index_offset_
== -1U)
1121 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1122 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1123 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1124 unsigned int got_offset
= got
->add_constant(0);
1125 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1127 got
->add_constant(0);
1128 this->got_mod_index_offset_
= got_offset
;
1130 return this->got_mod_index_offset_
;
1133 // Optimize the TLS relocation type based on what we know about the
1134 // symbol. IS_FINAL is true if the final address of this symbol is
1135 // known at link time.
1137 tls::Tls_optimization
1138 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1140 // If we are generating a shared library, then we can't do anything
1142 if (parameters
->options().shared())
1143 return tls::TLSOPT_NONE
;
1147 case elfcpp::R_386_TLS_GD
:
1148 case elfcpp::R_386_TLS_GOTDESC
:
1149 case elfcpp::R_386_TLS_DESC_CALL
:
1150 // These are General-Dynamic which permits fully general TLS
1151 // access. Since we know that we are generating an executable,
1152 // we can convert this to Initial-Exec. If we also know that
1153 // this is a local symbol, we can further switch to Local-Exec.
1155 return tls::TLSOPT_TO_LE
;
1156 return tls::TLSOPT_TO_IE
;
1158 case elfcpp::R_386_TLS_LDM
:
1159 // This is Local-Dynamic, which refers to a local symbol in the
1160 // dynamic TLS block. Since we know that we generating an
1161 // executable, we can switch to Local-Exec.
1162 return tls::TLSOPT_TO_LE
;
1164 case elfcpp::R_386_TLS_LDO_32
:
1165 // Another type of Local-Dynamic relocation.
1166 return tls::TLSOPT_TO_LE
;
1168 case elfcpp::R_386_TLS_IE
:
1169 case elfcpp::R_386_TLS_GOTIE
:
1170 case elfcpp::R_386_TLS_IE_32
:
1171 // These are Initial-Exec relocs which get the thread offset
1172 // from the GOT. If we know that we are linking against the
1173 // local symbol, we can switch to Local-Exec, which links the
1174 // thread offset into the instruction.
1176 return tls::TLSOPT_TO_LE
;
1177 return tls::TLSOPT_NONE
;
1179 case elfcpp::R_386_TLS_LE
:
1180 case elfcpp::R_386_TLS_LE_32
:
1181 // When we already have Local-Exec, there is nothing further we
1183 return tls::TLSOPT_NONE
;
1190 // Report an unsupported relocation against a local symbol.
1193 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
1194 unsigned int r_type
)
1196 gold_error(_("%s: unsupported reloc %u against local symbol"),
1197 object
->name().c_str(), r_type
);
1200 // Return whether we need to make a PLT entry for a relocation of a
1201 // given type against a STT_GNU_IFUNC symbol.
1204 Target_i386::Scan::reloc_needs_plt_for_ifunc(Sized_relobj
<32, false>* object
,
1205 unsigned int r_type
)
1209 case elfcpp::R_386_NONE
:
1210 case elfcpp::R_386_GNU_VTINHERIT
:
1211 case elfcpp::R_386_GNU_VTENTRY
:
1214 case elfcpp::R_386_32
:
1215 case elfcpp::R_386_16
:
1216 case elfcpp::R_386_8
:
1217 case elfcpp::R_386_PC32
:
1218 case elfcpp::R_386_PC16
:
1219 case elfcpp::R_386_PC8
:
1220 case elfcpp::R_386_PLT32
:
1221 case elfcpp::R_386_GOTOFF
:
1222 case elfcpp::R_386_GOTPC
:
1223 case elfcpp::R_386_GOT32
:
1226 case elfcpp::R_386_COPY
:
1227 case elfcpp::R_386_GLOB_DAT
:
1228 case elfcpp::R_386_JUMP_SLOT
:
1229 case elfcpp::R_386_RELATIVE
:
1230 case elfcpp::R_386_IRELATIVE
:
1231 case elfcpp::R_386_TLS_TPOFF
:
1232 case elfcpp::R_386_TLS_DTPMOD32
:
1233 case elfcpp::R_386_TLS_DTPOFF32
:
1234 case elfcpp::R_386_TLS_TPOFF32
:
1235 case elfcpp::R_386_TLS_DESC
:
1236 // We will give an error later.
1239 case elfcpp::R_386_TLS_GD
:
1240 case elfcpp::R_386_TLS_GOTDESC
:
1241 case elfcpp::R_386_TLS_DESC_CALL
:
1242 case elfcpp::R_386_TLS_LDM
:
1243 case elfcpp::R_386_TLS_LDO_32
:
1244 case elfcpp::R_386_TLS_IE
:
1245 case elfcpp::R_386_TLS_IE_32
:
1246 case elfcpp::R_386_TLS_GOTIE
:
1247 case elfcpp::R_386_TLS_LE
:
1248 case elfcpp::R_386_TLS_LE_32
:
1249 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1250 object
->name().c_str(), r_type
);
1253 case elfcpp::R_386_32PLT
:
1254 case elfcpp::R_386_TLS_GD_32
:
1255 case elfcpp::R_386_TLS_GD_PUSH
:
1256 case elfcpp::R_386_TLS_GD_CALL
:
1257 case elfcpp::R_386_TLS_GD_POP
:
1258 case elfcpp::R_386_TLS_LDM_32
:
1259 case elfcpp::R_386_TLS_LDM_PUSH
:
1260 case elfcpp::R_386_TLS_LDM_CALL
:
1261 case elfcpp::R_386_TLS_LDM_POP
:
1262 case elfcpp::R_386_USED_BY_INTEL_200
:
1264 // We will give an error later.
1269 // Scan a relocation for a local symbol.
1272 Target_i386::Scan::local(Symbol_table
* symtab
,
1274 Target_i386
* target
,
1275 Sized_relobj
<32, false>* object
,
1276 unsigned int data_shndx
,
1277 Output_section
* output_section
,
1278 const elfcpp::Rel
<32, false>& reloc
,
1279 unsigned int r_type
,
1280 const elfcpp::Sym
<32, false>& lsym
)
1282 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1283 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1284 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1286 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1287 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1292 case elfcpp::R_386_NONE
:
1293 case elfcpp::R_386_GNU_VTINHERIT
:
1294 case elfcpp::R_386_GNU_VTENTRY
:
1297 case elfcpp::R_386_32
:
1298 // If building a shared library (or a position-independent
1299 // executable), we need to create a dynamic relocation for
1300 // this location. The relocation applied at link time will
1301 // apply the link-time value, so we flag the location with
1302 // an R_386_RELATIVE relocation so the dynamic loader can
1303 // relocate it easily.
1304 if (parameters
->options().output_is_position_independent())
1306 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1307 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1308 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1309 output_section
, data_shndx
,
1310 reloc
.get_r_offset());
1314 case elfcpp::R_386_16
:
1315 case elfcpp::R_386_8
:
1316 // If building a shared library (or a position-independent
1317 // executable), we need to create a dynamic relocation for
1318 // this location. Because the addend needs to remain in the
1319 // data section, we need to be careful not to apply this
1320 // relocation statically.
1321 if (parameters
->options().output_is_position_independent())
1323 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1324 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1325 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1326 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1327 data_shndx
, reloc
.get_r_offset());
1330 gold_assert(lsym
.get_st_value() == 0);
1331 unsigned int shndx
= lsym
.get_st_shndx();
1333 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1336 object
->error(_("section symbol %u has bad shndx %u"),
1339 rel_dyn
->add_local_section(object
, shndx
,
1340 r_type
, output_section
,
1341 data_shndx
, reloc
.get_r_offset());
1346 case elfcpp::R_386_PC32
:
1347 case elfcpp::R_386_PC16
:
1348 case elfcpp::R_386_PC8
:
1351 case elfcpp::R_386_PLT32
:
1352 // Since we know this is a local symbol, we can handle this as a
1356 case elfcpp::R_386_GOTOFF
:
1357 case elfcpp::R_386_GOTPC
:
1358 // We need a GOT section.
1359 target
->got_section(symtab
, layout
);
1362 case elfcpp::R_386_GOT32
:
1364 // The symbol requires a GOT entry.
1365 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1366 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1368 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1369 // lets function pointers compare correctly with shared
1370 // libraries. Otherwise we would need an IRELATIVE reloc.
1372 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1373 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1375 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1378 // If we are generating a shared object, we need to add a
1379 // dynamic RELATIVE relocation for this symbol's GOT entry.
1380 if (parameters
->options().output_is_position_independent())
1382 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1383 unsigned int got_offset
=
1384 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1385 rel_dyn
->add_local_relative(object
, r_sym
,
1386 elfcpp::R_386_RELATIVE
,
1393 // These are relocations which should only be seen by the
1394 // dynamic linker, and should never be seen here.
1395 case elfcpp::R_386_COPY
:
1396 case elfcpp::R_386_GLOB_DAT
:
1397 case elfcpp::R_386_JUMP_SLOT
:
1398 case elfcpp::R_386_RELATIVE
:
1399 case elfcpp::R_386_IRELATIVE
:
1400 case elfcpp::R_386_TLS_TPOFF
:
1401 case elfcpp::R_386_TLS_DTPMOD32
:
1402 case elfcpp::R_386_TLS_DTPOFF32
:
1403 case elfcpp::R_386_TLS_TPOFF32
:
1404 case elfcpp::R_386_TLS_DESC
:
1405 gold_error(_("%s: unexpected reloc %u in object file"),
1406 object
->name().c_str(), r_type
);
1409 // These are initial TLS relocs, which are expected when
1411 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1412 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1413 case elfcpp::R_386_TLS_DESC_CALL
:
1414 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1415 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1416 case elfcpp::R_386_TLS_IE
: // Initial-exec
1417 case elfcpp::R_386_TLS_IE_32
:
1418 case elfcpp::R_386_TLS_GOTIE
:
1419 case elfcpp::R_386_TLS_LE
: // Local-exec
1420 case elfcpp::R_386_TLS_LE_32
:
1422 bool output_is_shared
= parameters
->options().shared();
1423 const tls::Tls_optimization optimized_type
1424 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1427 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1428 if (optimized_type
== tls::TLSOPT_NONE
)
1430 // Create a pair of GOT entries for the module index and
1431 // dtv-relative offset.
1432 Output_data_got
<32, false>* got
1433 = target
->got_section(symtab
, layout
);
1434 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1435 unsigned int shndx
= lsym
.get_st_shndx();
1437 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1439 object
->error(_("local symbol %u has bad shndx %u"),
1442 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1444 target
->rel_dyn_section(layout
),
1445 elfcpp::R_386_TLS_DTPMOD32
, 0);
1447 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1448 unsupported_reloc_local(object
, r_type
);
1451 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1452 target
->define_tls_base_symbol(symtab
, layout
);
1453 if (optimized_type
== tls::TLSOPT_NONE
)
1455 // Create a double GOT entry with an R_386_TLS_DESC
1456 // reloc. The R_386_TLS_DESC reloc is resolved
1457 // lazily, so the GOT entry needs to be in an area in
1458 // .got.plt, not .got. Call got_section to make sure
1459 // the section has been created.
1460 target
->got_section(symtab
, layout
);
1461 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1462 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1463 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1465 unsigned int got_offset
= got
->add_constant(0);
1466 // The local symbol value is stored in the second
1468 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1469 // That set the GOT offset of the local symbol to
1470 // point to the second entry, but we want it to
1471 // point to the first.
1472 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1474 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1475 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1478 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1479 unsupported_reloc_local(object
, r_type
);
1482 case elfcpp::R_386_TLS_DESC_CALL
:
1485 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1486 if (optimized_type
== tls::TLSOPT_NONE
)
1488 // Create a GOT entry for the module index.
1489 target
->got_mod_index_entry(symtab
, layout
, object
);
1491 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1492 unsupported_reloc_local(object
, r_type
);
1495 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1498 case elfcpp::R_386_TLS_IE
: // Initial-exec
1499 case elfcpp::R_386_TLS_IE_32
:
1500 case elfcpp::R_386_TLS_GOTIE
:
1501 layout
->set_has_static_tls();
1502 if (optimized_type
== tls::TLSOPT_NONE
)
1504 // For the R_386_TLS_IE relocation, we need to create a
1505 // dynamic relocation when building a shared library.
1506 if (r_type
== elfcpp::R_386_TLS_IE
1507 && parameters
->options().shared())
1509 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1511 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1512 rel_dyn
->add_local_relative(object
, r_sym
,
1513 elfcpp::R_386_RELATIVE
,
1514 output_section
, data_shndx
,
1515 reloc
.get_r_offset());
1517 // Create a GOT entry for the tp-relative offset.
1518 Output_data_got
<32, false>* got
1519 = target
->got_section(symtab
, layout
);
1520 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1521 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1522 ? elfcpp::R_386_TLS_TPOFF32
1523 : elfcpp::R_386_TLS_TPOFF
);
1524 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1525 ? GOT_TYPE_TLS_OFFSET
1526 : GOT_TYPE_TLS_NOFFSET
);
1527 got
->add_local_with_rel(object
, r_sym
, got_type
,
1528 target
->rel_dyn_section(layout
),
1531 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1532 unsupported_reloc_local(object
, r_type
);
1535 case elfcpp::R_386_TLS_LE
: // Local-exec
1536 case elfcpp::R_386_TLS_LE_32
:
1537 layout
->set_has_static_tls();
1538 if (output_is_shared
)
1540 // We need to create a dynamic relocation.
1541 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1542 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1543 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1544 ? elfcpp::R_386_TLS_TPOFF32
1545 : elfcpp::R_386_TLS_TPOFF
);
1546 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1547 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1548 data_shndx
, reloc
.get_r_offset());
1558 case elfcpp::R_386_32PLT
:
1559 case elfcpp::R_386_TLS_GD_32
:
1560 case elfcpp::R_386_TLS_GD_PUSH
:
1561 case elfcpp::R_386_TLS_GD_CALL
:
1562 case elfcpp::R_386_TLS_GD_POP
:
1563 case elfcpp::R_386_TLS_LDM_32
:
1564 case elfcpp::R_386_TLS_LDM_PUSH
:
1565 case elfcpp::R_386_TLS_LDM_CALL
:
1566 case elfcpp::R_386_TLS_LDM_POP
:
1567 case elfcpp::R_386_USED_BY_INTEL_200
:
1569 unsupported_reloc_local(object
, r_type
);
1574 // Report an unsupported relocation against a global symbol.
1577 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1578 unsigned int r_type
,
1581 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1582 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1586 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1590 case elfcpp::R_386_32
:
1591 case elfcpp::R_386_16
:
1592 case elfcpp::R_386_8
:
1593 case elfcpp::R_386_GOTOFF
:
1594 case elfcpp::R_386_GOT32
:
1605 Target_i386::Scan::local_reloc_may_be_function_pointer(
1609 Sized_relobj
<32, false>* ,
1612 const elfcpp::Rel
<32, false>& ,
1613 unsigned int r_type
,
1614 const elfcpp::Sym
<32, false>&)
1616 return possible_function_pointer_reloc(r_type
);
1620 Target_i386::Scan::global_reloc_may_be_function_pointer(
1624 Sized_relobj
<32, false>* ,
1627 const elfcpp::Rel
<32, false>& ,
1628 unsigned int r_type
,
1631 return possible_function_pointer_reloc(r_type
);
1634 // Scan a relocation for a global symbol.
1637 Target_i386::Scan::global(Symbol_table
* symtab
,
1639 Target_i386
* target
,
1640 Sized_relobj
<32, false>* object
,
1641 unsigned int data_shndx
,
1642 Output_section
* output_section
,
1643 const elfcpp::Rel
<32, false>& reloc
,
1644 unsigned int r_type
,
1647 // A STT_GNU_IFUNC symbol may require a PLT entry.
1648 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1649 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1650 target
->make_plt_entry(symtab
, layout
, gsym
);
1654 case elfcpp::R_386_NONE
:
1655 case elfcpp::R_386_GNU_VTINHERIT
:
1656 case elfcpp::R_386_GNU_VTENTRY
:
1659 case elfcpp::R_386_32
:
1660 case elfcpp::R_386_16
:
1661 case elfcpp::R_386_8
:
1663 // Make a PLT entry if necessary.
1664 if (gsym
->needs_plt_entry())
1666 target
->make_plt_entry(symtab
, layout
, gsym
);
1667 // Since this is not a PC-relative relocation, we may be
1668 // taking the address of a function. In that case we need to
1669 // set the entry in the dynamic symbol table to the address of
1671 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1672 gsym
->set_needs_dynsym_value();
1674 // Make a dynamic relocation if necessary.
1675 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1677 if (gsym
->may_need_copy_reloc())
1679 target
->copy_reloc(symtab
, layout
, object
,
1680 data_shndx
, output_section
, gsym
, reloc
);
1682 else if (r_type
== elfcpp::R_386_32
1683 && gsym
->type() == elfcpp::STT_GNU_IFUNC
1684 && gsym
->can_use_relative_reloc(false)
1685 && !gsym
->is_from_dynobj()
1686 && !gsym
->is_undefined()
1687 && !gsym
->is_preemptible())
1689 // Use an IRELATIVE reloc for a locally defined
1690 // STT_GNU_IFUNC symbol. This makes a function
1691 // address in a PIE executable match the address in a
1692 // shared library that it links against.
1693 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1694 rel_dyn
->add_symbolless_global_addend(gsym
,
1695 elfcpp::R_386_IRELATIVE
,
1698 reloc
.get_r_offset());
1700 else if (r_type
== elfcpp::R_386_32
1701 && gsym
->can_use_relative_reloc(false))
1703 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1704 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1705 output_section
, object
,
1706 data_shndx
, reloc
.get_r_offset());
1710 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1711 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1712 data_shndx
, reloc
.get_r_offset());
1718 case elfcpp::R_386_PC32
:
1719 case elfcpp::R_386_PC16
:
1720 case elfcpp::R_386_PC8
:
1722 // Make a PLT entry if necessary.
1723 if (gsym
->needs_plt_entry())
1725 // These relocations are used for function calls only in
1726 // non-PIC code. For a 32-bit relocation in a shared library,
1727 // we'll need a text relocation anyway, so we can skip the
1728 // PLT entry and let the dynamic linker bind the call directly
1729 // to the target. For smaller relocations, we should use a
1730 // PLT entry to ensure that the call can reach.
1731 if (!parameters
->options().shared()
1732 || r_type
!= elfcpp::R_386_PC32
)
1733 target
->make_plt_entry(symtab
, layout
, gsym
);
1735 // Make a dynamic relocation if necessary.
1736 int flags
= Symbol::NON_PIC_REF
;
1737 if (gsym
->is_func())
1738 flags
|= Symbol::FUNCTION_CALL
;
1739 if (gsym
->needs_dynamic_reloc(flags
))
1741 if (gsym
->may_need_copy_reloc())
1743 target
->copy_reloc(symtab
, layout
, object
,
1744 data_shndx
, output_section
, gsym
, reloc
);
1748 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1749 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1750 data_shndx
, reloc
.get_r_offset());
1756 case elfcpp::R_386_GOT32
:
1758 // The symbol requires a GOT entry.
1759 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1760 if (gsym
->final_value_is_known())
1762 // For a STT_GNU_IFUNC symbol we want the PLT address.
1763 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1764 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1766 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1770 // If this symbol is not fully resolved, we need to add a
1771 // GOT entry with a dynamic relocation.
1772 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1773 if (gsym
->is_from_dynobj()
1774 || gsym
->is_undefined()
1775 || gsym
->is_preemptible()
1776 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
1777 && parameters
->options().output_is_position_independent()))
1778 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1779 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1782 // For a STT_GNU_IFUNC symbol we want to write the PLT
1783 // offset into the GOT, so that function pointer
1784 // comparisons work correctly.
1786 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
1787 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1790 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1791 // Tell the dynamic linker to use the PLT address
1792 // when resolving relocations.
1793 if (gsym
->is_from_dynobj()
1794 && !parameters
->options().shared())
1795 gsym
->set_needs_dynsym_value();
1799 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
1800 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1808 case elfcpp::R_386_PLT32
:
1809 // If the symbol is fully resolved, this is just a PC32 reloc.
1810 // Otherwise we need a PLT entry.
1811 if (gsym
->final_value_is_known())
1813 // If building a shared library, we can also skip the PLT entry
1814 // if the symbol is defined in the output file and is protected
1816 if (gsym
->is_defined()
1817 && !gsym
->is_from_dynobj()
1818 && !gsym
->is_preemptible())
1820 target
->make_plt_entry(symtab
, layout
, gsym
);
1823 case elfcpp::R_386_GOTOFF
:
1824 case elfcpp::R_386_GOTPC
:
1825 // We need a GOT section.
1826 target
->got_section(symtab
, layout
);
1829 // These are relocations which should only be seen by the
1830 // dynamic linker, and should never be seen here.
1831 case elfcpp::R_386_COPY
:
1832 case elfcpp::R_386_GLOB_DAT
:
1833 case elfcpp::R_386_JUMP_SLOT
:
1834 case elfcpp::R_386_RELATIVE
:
1835 case elfcpp::R_386_IRELATIVE
:
1836 case elfcpp::R_386_TLS_TPOFF
:
1837 case elfcpp::R_386_TLS_DTPMOD32
:
1838 case elfcpp::R_386_TLS_DTPOFF32
:
1839 case elfcpp::R_386_TLS_TPOFF32
:
1840 case elfcpp::R_386_TLS_DESC
:
1841 gold_error(_("%s: unexpected reloc %u in object file"),
1842 object
->name().c_str(), r_type
);
1845 // These are initial tls relocs, which are expected when
1847 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1848 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1849 case elfcpp::R_386_TLS_DESC_CALL
:
1850 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1851 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1852 case elfcpp::R_386_TLS_IE
: // Initial-exec
1853 case elfcpp::R_386_TLS_IE_32
:
1854 case elfcpp::R_386_TLS_GOTIE
:
1855 case elfcpp::R_386_TLS_LE
: // Local-exec
1856 case elfcpp::R_386_TLS_LE_32
:
1858 const bool is_final
= gsym
->final_value_is_known();
1859 const tls::Tls_optimization optimized_type
1860 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1863 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1864 if (optimized_type
== tls::TLSOPT_NONE
)
1866 // Create a pair of GOT entries for the module index and
1867 // dtv-relative offset.
1868 Output_data_got
<32, false>* got
1869 = target
->got_section(symtab
, layout
);
1870 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1871 target
->rel_dyn_section(layout
),
1872 elfcpp::R_386_TLS_DTPMOD32
,
1873 elfcpp::R_386_TLS_DTPOFF32
);
1875 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1877 // Create a GOT entry for the tp-relative offset.
1878 Output_data_got
<32, false>* got
1879 = target
->got_section(symtab
, layout
);
1880 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1881 target
->rel_dyn_section(layout
),
1882 elfcpp::R_386_TLS_TPOFF
);
1884 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1885 unsupported_reloc_global(object
, r_type
, gsym
);
1888 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1889 target
->define_tls_base_symbol(symtab
, layout
);
1890 if (optimized_type
== tls::TLSOPT_NONE
)
1892 // Create a double GOT entry with an R_386_TLS_DESC
1893 // reloc. The R_386_TLS_DESC reloc is resolved
1894 // lazily, so the GOT entry needs to be in an area in
1895 // .got.plt, not .got. Call got_section to make sure
1896 // the section has been created.
1897 target
->got_section(symtab
, layout
);
1898 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1899 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1900 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1901 elfcpp::R_386_TLS_DESC
, 0);
1903 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1905 // Create a GOT entry for the tp-relative offset.
1906 Output_data_got
<32, false>* got
1907 = target
->got_section(symtab
, layout
);
1908 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1909 target
->rel_dyn_section(layout
),
1910 elfcpp::R_386_TLS_TPOFF
);
1912 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1913 unsupported_reloc_global(object
, r_type
, gsym
);
1916 case elfcpp::R_386_TLS_DESC_CALL
:
1919 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1920 if (optimized_type
== tls::TLSOPT_NONE
)
1922 // Create a GOT entry for the module index.
1923 target
->got_mod_index_entry(symtab
, layout
, object
);
1925 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1926 unsupported_reloc_global(object
, r_type
, gsym
);
1929 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1932 case elfcpp::R_386_TLS_IE
: // Initial-exec
1933 case elfcpp::R_386_TLS_IE_32
:
1934 case elfcpp::R_386_TLS_GOTIE
:
1935 layout
->set_has_static_tls();
1936 if (optimized_type
== tls::TLSOPT_NONE
)
1938 // For the R_386_TLS_IE relocation, we need to create a
1939 // dynamic relocation when building a shared library.
1940 if (r_type
== elfcpp::R_386_TLS_IE
1941 && parameters
->options().shared())
1943 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1944 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1945 output_section
, object
,
1947 reloc
.get_r_offset());
1949 // Create a GOT entry for the tp-relative offset.
1950 Output_data_got
<32, false>* got
1951 = target
->got_section(symtab
, layout
);
1952 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1953 ? elfcpp::R_386_TLS_TPOFF32
1954 : elfcpp::R_386_TLS_TPOFF
);
1955 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1956 ? GOT_TYPE_TLS_OFFSET
1957 : GOT_TYPE_TLS_NOFFSET
);
1958 got
->add_global_with_rel(gsym
, got_type
,
1959 target
->rel_dyn_section(layout
),
1962 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1963 unsupported_reloc_global(object
, r_type
, gsym
);
1966 case elfcpp::R_386_TLS_LE
: // Local-exec
1967 case elfcpp::R_386_TLS_LE_32
:
1968 layout
->set_has_static_tls();
1969 if (parameters
->options().shared())
1971 // We need to create a dynamic relocation.
1972 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1973 ? elfcpp::R_386_TLS_TPOFF32
1974 : elfcpp::R_386_TLS_TPOFF
);
1975 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1976 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1977 data_shndx
, reloc
.get_r_offset());
1987 case elfcpp::R_386_32PLT
:
1988 case elfcpp::R_386_TLS_GD_32
:
1989 case elfcpp::R_386_TLS_GD_PUSH
:
1990 case elfcpp::R_386_TLS_GD_CALL
:
1991 case elfcpp::R_386_TLS_GD_POP
:
1992 case elfcpp::R_386_TLS_LDM_32
:
1993 case elfcpp::R_386_TLS_LDM_PUSH
:
1994 case elfcpp::R_386_TLS_LDM_CALL
:
1995 case elfcpp::R_386_TLS_LDM_POP
:
1996 case elfcpp::R_386_USED_BY_INTEL_200
:
1998 unsupported_reloc_global(object
, r_type
, gsym
);
2003 // Process relocations for gc.
2006 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2008 Sized_relobj
<32, false>* object
,
2009 unsigned int data_shndx
,
2011 const unsigned char* prelocs
,
2013 Output_section
* output_section
,
2014 bool needs_special_offset_handling
,
2015 size_t local_symbol_count
,
2016 const unsigned char* plocal_symbols
)
2018 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2020 Target_i386::Relocatable_size_for_reloc
>(
2029 needs_special_offset_handling
,
2034 // Scan relocations for a section.
2037 Target_i386::scan_relocs(Symbol_table
* symtab
,
2039 Sized_relobj
<32, false>* object
,
2040 unsigned int data_shndx
,
2041 unsigned int sh_type
,
2042 const unsigned char* prelocs
,
2044 Output_section
* output_section
,
2045 bool needs_special_offset_handling
,
2046 size_t local_symbol_count
,
2047 const unsigned char* plocal_symbols
)
2049 if (sh_type
== elfcpp::SHT_RELA
)
2051 gold_error(_("%s: unsupported RELA reloc section"),
2052 object
->name().c_str());
2056 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2066 needs_special_offset_handling
,
2071 // Finalize the sections.
2074 Target_i386::do_finalize_sections(
2076 const Input_objects
*,
2077 Symbol_table
* symtab
)
2079 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2081 : this->plt_
->rel_plt());
2082 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2083 this->rel_dyn_
, true, false);
2085 // Emit any relocs we saved in an attempt to avoid generating COPY
2087 if (this->copy_relocs_
.any_saved_relocs())
2088 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2090 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2091 // the .got.plt section.
2092 Symbol
* sym
= this->global_offset_table_
;
2095 uint32_t data_size
= this->got_plt_
->current_data_size();
2096 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2100 // Return whether a direct absolute static relocation needs to be applied.
2101 // In cases where Scan::local() or Scan::global() has created
2102 // a dynamic relocation other than R_386_RELATIVE, the addend
2103 // of the relocation is carried in the data, and we must not
2104 // apply the static relocation.
2107 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2110 Output_section
* output_section
)
2112 // If the output section is not allocated, then we didn't call
2113 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2115 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2118 // For local symbols, we will have created a non-RELATIVE dynamic
2119 // relocation only if (a) the output is position independent,
2120 // (b) the relocation is absolute (not pc- or segment-relative), and
2121 // (c) the relocation is not 32 bits wide.
2123 return !(parameters
->options().output_is_position_independent()
2124 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2127 // For global symbols, we use the same helper routines used in the
2128 // scan pass. If we did not create a dynamic relocation, or if we
2129 // created a RELATIVE dynamic relocation, we should apply the static
2131 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2132 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2133 && gsym
->can_use_relative_reloc(ref_flags
2134 & Symbol::FUNCTION_CALL
);
2135 return !has_dyn
|| is_rel
;
2138 // Perform a relocation.
2141 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2142 Target_i386
* target
,
2143 Output_section
*output_section
,
2145 const elfcpp::Rel
<32, false>& rel
,
2146 unsigned int r_type
,
2147 const Sized_symbol
<32>* gsym
,
2148 const Symbol_value
<32>* psymval
,
2149 unsigned char* view
,
2150 elfcpp::Elf_types
<32>::Elf_Addr address
,
2151 section_size_type view_size
)
2153 if (this->skip_call_tls_get_addr_
)
2155 if ((r_type
!= elfcpp::R_386_PLT32
2156 && r_type
!= elfcpp::R_386_PC32
)
2158 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2159 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2160 _("missing expected TLS relocation"));
2163 this->skip_call_tls_get_addr_
= false;
2168 const Sized_relobj
<32, false>* object
= relinfo
->object
;
2170 // Pick the value to use for symbols defined in shared objects.
2171 Symbol_value
<32> symval
;
2173 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2174 && r_type
== elfcpp::R_386_32
2175 && gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
)
2176 && gsym
->can_use_relative_reloc(false)
2177 && !gsym
->is_from_dynobj()
2178 && !gsym
->is_undefined()
2179 && !gsym
->is_preemptible())
2181 // In this case we are generating a R_386_IRELATIVE reloc. We
2182 // want to use the real value of the symbol, not the PLT offset.
2184 else if (gsym
!= NULL
2185 && gsym
->use_plt_offset(r_type
== elfcpp::R_386_PC8
2186 || r_type
== elfcpp::R_386_PC16
2187 || r_type
== elfcpp::R_386_PC32
))
2189 symval
.set_output_value(target
->plt_section()->address()
2190 + gsym
->plt_offset());
2193 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2195 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2196 if (object
->local_has_plt_offset(r_sym
))
2198 symval
.set_output_value(target
->plt_section()->address()
2199 + object
->local_plt_offset(r_sym
));
2204 // Get the GOT offset if needed.
2205 // The GOT pointer points to the end of the GOT section.
2206 // We need to subtract the size of the GOT section to get
2207 // the actual offset to use in the relocation.
2208 bool have_got_offset
= false;
2209 unsigned int got_offset
= 0;
2212 case elfcpp::R_386_GOT32
:
2215 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2216 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2217 - target
->got_size());
2221 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2222 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2223 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2224 - target
->got_size());
2226 have_got_offset
= true;
2235 case elfcpp::R_386_NONE
:
2236 case elfcpp::R_386_GNU_VTINHERIT
:
2237 case elfcpp::R_386_GNU_VTENTRY
:
2240 case elfcpp::R_386_32
:
2241 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
2243 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2246 case elfcpp::R_386_PC32
:
2248 int ref_flags
= Symbol::NON_PIC_REF
;
2249 if (gsym
!= NULL
&& gsym
->is_func())
2250 ref_flags
|= Symbol::FUNCTION_CALL
;
2251 if (should_apply_static_reloc(gsym
, ref_flags
, true, output_section
))
2252 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2256 case elfcpp::R_386_16
:
2257 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
2259 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2262 case elfcpp::R_386_PC16
:
2264 int ref_flags
= Symbol::NON_PIC_REF
;
2265 if (gsym
!= NULL
&& gsym
->is_func())
2266 ref_flags
|= Symbol::FUNCTION_CALL
;
2267 if (should_apply_static_reloc(gsym
, ref_flags
, false, output_section
))
2268 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2272 case elfcpp::R_386_8
:
2273 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
2275 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2278 case elfcpp::R_386_PC8
:
2280 int ref_flags
= Symbol::NON_PIC_REF
;
2281 if (gsym
!= NULL
&& gsym
->is_func())
2282 ref_flags
|= Symbol::FUNCTION_CALL
;
2283 if (should_apply_static_reloc(gsym
, ref_flags
, false,
2285 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2289 case elfcpp::R_386_PLT32
:
2290 gold_assert(gsym
== NULL
2291 || gsym
->has_plt_offset()
2292 || gsym
->final_value_is_known()
2293 || (gsym
->is_defined()
2294 && !gsym
->is_from_dynobj()
2295 && !gsym
->is_preemptible()));
2296 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2299 case elfcpp::R_386_GOT32
:
2300 gold_assert(have_got_offset
);
2301 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2304 case elfcpp::R_386_GOTOFF
:
2306 elfcpp::Elf_types
<32>::Elf_Addr value
;
2307 value
= (psymval
->value(object
, 0)
2308 - target
->got_plt_section()->address());
2309 Relocate_functions
<32, false>::rel32(view
, value
);
2313 case elfcpp::R_386_GOTPC
:
2315 elfcpp::Elf_types
<32>::Elf_Addr value
;
2316 value
= target
->got_plt_section()->address();
2317 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2321 case elfcpp::R_386_COPY
:
2322 case elfcpp::R_386_GLOB_DAT
:
2323 case elfcpp::R_386_JUMP_SLOT
:
2324 case elfcpp::R_386_RELATIVE
:
2325 case elfcpp::R_386_IRELATIVE
:
2326 // These are outstanding tls relocs, which are unexpected when
2328 case elfcpp::R_386_TLS_TPOFF
:
2329 case elfcpp::R_386_TLS_DTPMOD32
:
2330 case elfcpp::R_386_TLS_DTPOFF32
:
2331 case elfcpp::R_386_TLS_TPOFF32
:
2332 case elfcpp::R_386_TLS_DESC
:
2333 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2334 _("unexpected reloc %u in object file"),
2338 // These are initial tls relocs, which are expected when
2340 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2341 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2342 case elfcpp::R_386_TLS_DESC_CALL
:
2343 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2344 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2345 case elfcpp::R_386_TLS_IE
: // Initial-exec
2346 case elfcpp::R_386_TLS_IE_32
:
2347 case elfcpp::R_386_TLS_GOTIE
:
2348 case elfcpp::R_386_TLS_LE
: // Local-exec
2349 case elfcpp::R_386_TLS_LE_32
:
2350 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2351 view
, address
, view_size
);
2354 case elfcpp::R_386_32PLT
:
2355 case elfcpp::R_386_TLS_GD_32
:
2356 case elfcpp::R_386_TLS_GD_PUSH
:
2357 case elfcpp::R_386_TLS_GD_CALL
:
2358 case elfcpp::R_386_TLS_GD_POP
:
2359 case elfcpp::R_386_TLS_LDM_32
:
2360 case elfcpp::R_386_TLS_LDM_PUSH
:
2361 case elfcpp::R_386_TLS_LDM_CALL
:
2362 case elfcpp::R_386_TLS_LDM_POP
:
2363 case elfcpp::R_386_USED_BY_INTEL_200
:
2365 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2366 _("unsupported reloc %u"),
2374 // Perform a TLS relocation.
2377 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2378 Target_i386
* target
,
2380 const elfcpp::Rel
<32, false>& rel
,
2381 unsigned int r_type
,
2382 const Sized_symbol
<32>* gsym
,
2383 const Symbol_value
<32>* psymval
,
2384 unsigned char* view
,
2385 elfcpp::Elf_types
<32>::Elf_Addr
,
2386 section_size_type view_size
)
2388 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2390 const Sized_relobj
<32, false>* object
= relinfo
->object
;
2392 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2394 const bool is_final
= (gsym
== NULL
2395 ? !parameters
->options().shared()
2396 : gsym
->final_value_is_known());
2397 const tls::Tls_optimization optimized_type
2398 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2401 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2402 if (optimized_type
== tls::TLSOPT_TO_LE
)
2404 gold_assert(tls_segment
!= NULL
);
2405 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2406 rel
, r_type
, value
, view
,
2412 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2413 ? GOT_TYPE_TLS_NOFFSET
2414 : GOT_TYPE_TLS_PAIR
);
2415 unsigned int got_offset
;
2418 gold_assert(gsym
->has_got_offset(got_type
));
2419 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2423 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2424 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2425 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2426 - target
->got_size());
2428 if (optimized_type
== tls::TLSOPT_TO_IE
)
2430 gold_assert(tls_segment
!= NULL
);
2431 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2432 got_offset
, view
, view_size
);
2435 else if (optimized_type
== tls::TLSOPT_NONE
)
2437 // Relocate the field with the offset of the pair of GOT
2439 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2443 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2444 _("unsupported reloc %u"),
2448 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2449 case elfcpp::R_386_TLS_DESC_CALL
:
2450 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2451 if (optimized_type
== tls::TLSOPT_TO_LE
)
2453 gold_assert(tls_segment
!= NULL
);
2454 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2455 rel
, r_type
, value
, view
,
2461 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2462 ? GOT_TYPE_TLS_NOFFSET
2463 : GOT_TYPE_TLS_DESC
);
2464 unsigned int got_offset
= 0;
2465 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2466 && optimized_type
== tls::TLSOPT_NONE
)
2468 // We created GOT entries in the .got.tlsdesc portion of
2469 // the .got.plt section, but the offset stored in the
2470 // symbol is the offset within .got.tlsdesc.
2471 got_offset
= (target
->got_size()
2472 + target
->got_plt_section()->data_size());
2476 gold_assert(gsym
->has_got_offset(got_type
));
2477 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2481 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2482 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2483 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2484 - target
->got_size());
2486 if (optimized_type
== tls::TLSOPT_TO_IE
)
2488 gold_assert(tls_segment
!= NULL
);
2489 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2490 got_offset
, view
, view_size
);
2493 else if (optimized_type
== tls::TLSOPT_NONE
)
2495 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2497 // Relocate the field with the offset of the pair of GOT
2499 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2504 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2505 _("unsupported reloc %u"),
2509 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2510 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2512 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2513 _("both SUN and GNU model "
2514 "TLS relocations"));
2517 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2518 if (optimized_type
== tls::TLSOPT_TO_LE
)
2520 gold_assert(tls_segment
!= NULL
);
2521 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2522 value
, view
, view_size
);
2525 else if (optimized_type
== tls::TLSOPT_NONE
)
2527 // Relocate the field with the offset of the GOT entry for
2528 // the module index.
2529 unsigned int got_offset
;
2530 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2531 - target
->got_size());
2532 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2535 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2536 _("unsupported reloc %u"),
2540 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2541 if (optimized_type
== tls::TLSOPT_TO_LE
)
2543 // This reloc can appear in debugging sections, in which
2544 // case we must not convert to local-exec. We decide what
2545 // to do based on whether the section is marked as
2546 // containing executable code. That is what the GNU linker
2548 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
2549 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
2551 gold_assert(tls_segment
!= NULL
);
2552 value
-= tls_segment
->memsz();
2555 Relocate_functions
<32, false>::rel32(view
, value
);
2558 case elfcpp::R_386_TLS_IE
: // Initial-exec
2559 case elfcpp::R_386_TLS_GOTIE
:
2560 case elfcpp::R_386_TLS_IE_32
:
2561 if (optimized_type
== tls::TLSOPT_TO_LE
)
2563 gold_assert(tls_segment
!= NULL
);
2564 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2565 rel
, r_type
, value
, view
,
2569 else if (optimized_type
== tls::TLSOPT_NONE
)
2571 // Relocate the field with the offset of the GOT entry for
2572 // the tp-relative offset of the symbol.
2573 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2574 ? GOT_TYPE_TLS_OFFSET
2575 : GOT_TYPE_TLS_NOFFSET
);
2576 unsigned int got_offset
;
2579 gold_assert(gsym
->has_got_offset(got_type
));
2580 got_offset
= gsym
->got_offset(got_type
);
2584 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2585 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2586 got_offset
= object
->local_got_offset(r_sym
, got_type
);
2588 // For the R_386_TLS_IE relocation, we need to apply the
2589 // absolute address of the GOT entry.
2590 if (r_type
== elfcpp::R_386_TLS_IE
)
2591 got_offset
+= target
->got_plt_section()->address();
2592 // All GOT offsets are relative to the end of the GOT.
2593 got_offset
-= target
->got_size();
2594 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2597 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2598 _("unsupported reloc %u"),
2602 case elfcpp::R_386_TLS_LE
: // Local-exec
2603 // If we're creating a shared library, a dynamic relocation will
2604 // have been created for this location, so do not apply it now.
2605 if (!parameters
->options().shared())
2607 gold_assert(tls_segment
!= NULL
);
2608 value
-= tls_segment
->memsz();
2609 Relocate_functions
<32, false>::rel32(view
, value
);
2613 case elfcpp::R_386_TLS_LE_32
:
2614 // If we're creating a shared library, a dynamic relocation will
2615 // have been created for this location, so do not apply it now.
2616 if (!parameters
->options().shared())
2618 gold_assert(tls_segment
!= NULL
);
2619 value
= tls_segment
->memsz() - value
;
2620 Relocate_functions
<32, false>::rel32(view
, value
);
2626 // Do a relocation in which we convert a TLS General-Dynamic to a
2630 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2632 Output_segment
* tls_segment
,
2633 const elfcpp::Rel
<32, false>& rel
,
2635 elfcpp::Elf_types
<32>::Elf_Addr value
,
2636 unsigned char* view
,
2637 section_size_type view_size
)
2639 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2640 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2641 // leal foo(%reg),%eax; call ___tls_get_addr
2642 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2644 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2645 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2647 unsigned char op1
= view
[-1];
2648 unsigned char op2
= view
[-2];
2650 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2651 op2
== 0x8d || op2
== 0x04);
2652 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2658 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2659 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2660 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2661 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2662 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2666 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2667 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2668 if (rel
.get_r_offset() + 9 < view_size
2671 // There is a trailing nop. Use the size byte subl.
2672 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2677 // Use the five byte subl.
2678 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2682 value
= tls_segment
->memsz() - value
;
2683 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2685 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2687 this->skip_call_tls_get_addr_
= true;
2690 // Do a relocation in which we convert a TLS General-Dynamic to an
2694 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2697 const elfcpp::Rel
<32, false>& rel
,
2699 elfcpp::Elf_types
<32>::Elf_Addr value
,
2700 unsigned char* view
,
2701 section_size_type view_size
)
2703 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2704 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2706 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2707 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2709 unsigned char op1
= view
[-1];
2710 unsigned char op2
= view
[-2];
2712 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2713 op2
== 0x8d || op2
== 0x04);
2714 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2718 // FIXME: For now, support only the first (SIB) form.
2719 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2723 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2724 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2725 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2726 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2727 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2731 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2732 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2733 if (rel
.get_r_offset() + 9 < view_size
2736 // FIXME: This is not the right instruction sequence.
2737 // There is a trailing nop. Use the size byte subl.
2738 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2743 // FIXME: This is not the right instruction sequence.
2744 // Use the five byte subl.
2745 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2749 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2751 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2753 this->skip_call_tls_get_addr_
= true;
2756 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2757 // General-Dynamic to a Local-Exec.
2760 Target_i386::Relocate::tls_desc_gd_to_le(
2761 const Relocate_info
<32, false>* relinfo
,
2763 Output_segment
* tls_segment
,
2764 const elfcpp::Rel
<32, false>& rel
,
2765 unsigned int r_type
,
2766 elfcpp::Elf_types
<32>::Elf_Addr value
,
2767 unsigned char* view
,
2768 section_size_type view_size
)
2770 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2772 // leal foo@TLSDESC(%ebx), %eax
2773 // ==> leal foo@NTPOFF, %eax
2774 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2775 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2776 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2777 view
[-2] == 0x8d && view
[-1] == 0x83);
2779 value
-= tls_segment
->memsz();
2780 Relocate_functions
<32, false>::rel32(view
, value
);
2784 // call *foo@TLSCALL(%eax)
2786 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2787 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2788 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2789 view
[0] == 0xff && view
[1] == 0x10);
2795 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2796 // General-Dynamic to an Initial-Exec.
2799 Target_i386::Relocate::tls_desc_gd_to_ie(
2800 const Relocate_info
<32, false>* relinfo
,
2803 const elfcpp::Rel
<32, false>& rel
,
2804 unsigned int r_type
,
2805 elfcpp::Elf_types
<32>::Elf_Addr value
,
2806 unsigned char* view
,
2807 section_size_type view_size
)
2809 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2811 // leal foo@TLSDESC(%ebx), %eax
2812 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2813 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2814 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2815 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2816 view
[-2] == 0x8d && view
[-1] == 0x83);
2818 Relocate_functions
<32, false>::rel32(view
, value
);
2822 // call *foo@TLSCALL(%eax)
2824 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2825 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2826 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2827 view
[0] == 0xff && view
[1] == 0x10);
2833 // Do a relocation in which we convert a TLS Local-Dynamic to a
2837 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2840 const elfcpp::Rel
<32, false>& rel
,
2842 elfcpp::Elf_types
<32>::Elf_Addr
,
2843 unsigned char* view
,
2844 section_size_type view_size
)
2846 // leal foo(%reg), %eax; call ___tls_get_addr
2847 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2849 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2850 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2852 // FIXME: Does this test really always pass?
2853 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2854 view
[-2] == 0x8d && view
[-1] == 0x83);
2856 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2858 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2860 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2862 this->skip_call_tls_get_addr_
= true;
2865 // Do a relocation in which we convert a TLS Initial-Exec to a
2869 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2871 Output_segment
* tls_segment
,
2872 const elfcpp::Rel
<32, false>& rel
,
2873 unsigned int r_type
,
2874 elfcpp::Elf_types
<32>::Elf_Addr value
,
2875 unsigned char* view
,
2876 section_size_type view_size
)
2878 // We have to actually change the instructions, which means that we
2879 // need to examine the opcodes to figure out which instruction we
2881 if (r_type
== elfcpp::R_386_TLS_IE
)
2883 // movl %gs:XX,%eax ==> movl $YY,%eax
2884 // movl %gs:XX,%reg ==> movl $YY,%reg
2885 // addl %gs:XX,%reg ==> addl $YY,%reg
2886 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2887 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2889 unsigned char op1
= view
[-1];
2892 // movl XX,%eax ==> movl $YY,%eax
2897 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2899 unsigned char op2
= view
[-2];
2902 // movl XX,%reg ==> movl $YY,%reg
2903 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2904 (op1
& 0xc7) == 0x05);
2906 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2908 else if (op2
== 0x03)
2910 // addl XX,%reg ==> addl $YY,%reg
2911 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2912 (op1
& 0xc7) == 0x05);
2914 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2917 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2922 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2923 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2924 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2925 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2926 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2928 unsigned char op1
= view
[-1];
2929 unsigned char op2
= view
[-2];
2930 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2931 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2934 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2936 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2938 else if (op2
== 0x2b)
2940 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2942 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2944 else if (op2
== 0x03)
2946 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2948 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2951 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2954 value
= tls_segment
->memsz() - value
;
2955 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2958 Relocate_functions
<32, false>::rel32(view
, value
);
2961 // Relocate section data.
2964 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2965 unsigned int sh_type
,
2966 const unsigned char* prelocs
,
2968 Output_section
* output_section
,
2969 bool needs_special_offset_handling
,
2970 unsigned char* view
,
2971 elfcpp::Elf_types
<32>::Elf_Addr address
,
2972 section_size_type view_size
,
2973 const Reloc_symbol_changes
* reloc_symbol_changes
)
2975 gold_assert(sh_type
== elfcpp::SHT_REL
);
2977 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2978 Target_i386::Relocate
>(
2984 needs_special_offset_handling
,
2988 reloc_symbol_changes
);
2991 // Return the size of a relocation while scanning during a relocatable
2995 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2996 unsigned int r_type
,
3001 case elfcpp::R_386_NONE
:
3002 case elfcpp::R_386_GNU_VTINHERIT
:
3003 case elfcpp::R_386_GNU_VTENTRY
:
3004 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3005 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3006 case elfcpp::R_386_TLS_DESC_CALL
:
3007 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3008 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3009 case elfcpp::R_386_TLS_IE
: // Initial-exec
3010 case elfcpp::R_386_TLS_IE_32
:
3011 case elfcpp::R_386_TLS_GOTIE
:
3012 case elfcpp::R_386_TLS_LE
: // Local-exec
3013 case elfcpp::R_386_TLS_LE_32
:
3016 case elfcpp::R_386_32
:
3017 case elfcpp::R_386_PC32
:
3018 case elfcpp::R_386_GOT32
:
3019 case elfcpp::R_386_PLT32
:
3020 case elfcpp::R_386_GOTOFF
:
3021 case elfcpp::R_386_GOTPC
:
3024 case elfcpp::R_386_16
:
3025 case elfcpp::R_386_PC16
:
3028 case elfcpp::R_386_8
:
3029 case elfcpp::R_386_PC8
:
3032 // These are relocations which should only be seen by the
3033 // dynamic linker, and should never be seen here.
3034 case elfcpp::R_386_COPY
:
3035 case elfcpp::R_386_GLOB_DAT
:
3036 case elfcpp::R_386_JUMP_SLOT
:
3037 case elfcpp::R_386_RELATIVE
:
3038 case elfcpp::R_386_IRELATIVE
:
3039 case elfcpp::R_386_TLS_TPOFF
:
3040 case elfcpp::R_386_TLS_DTPMOD32
:
3041 case elfcpp::R_386_TLS_DTPOFF32
:
3042 case elfcpp::R_386_TLS_TPOFF32
:
3043 case elfcpp::R_386_TLS_DESC
:
3044 object
->error(_("unexpected reloc %u in object file"), r_type
);
3047 case elfcpp::R_386_32PLT
:
3048 case elfcpp::R_386_TLS_GD_32
:
3049 case elfcpp::R_386_TLS_GD_PUSH
:
3050 case elfcpp::R_386_TLS_GD_CALL
:
3051 case elfcpp::R_386_TLS_GD_POP
:
3052 case elfcpp::R_386_TLS_LDM_32
:
3053 case elfcpp::R_386_TLS_LDM_PUSH
:
3054 case elfcpp::R_386_TLS_LDM_CALL
:
3055 case elfcpp::R_386_TLS_LDM_POP
:
3056 case elfcpp::R_386_USED_BY_INTEL_200
:
3058 object
->error(_("unsupported reloc %u in object file"), r_type
);
3063 // Scan the relocs during a relocatable link.
3066 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3068 Sized_relobj
<32, false>* object
,
3069 unsigned int data_shndx
,
3070 unsigned int sh_type
,
3071 const unsigned char* prelocs
,
3073 Output_section
* output_section
,
3074 bool needs_special_offset_handling
,
3075 size_t local_symbol_count
,
3076 const unsigned char* plocal_symbols
,
3077 Relocatable_relocs
* rr
)
3079 gold_assert(sh_type
== elfcpp::SHT_REL
);
3081 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3082 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3084 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3085 Scan_relocatable_relocs
>(
3093 needs_special_offset_handling
,
3099 // Relocate a section during a relocatable link.
3102 Target_i386::relocate_for_relocatable(
3103 const Relocate_info
<32, false>* relinfo
,
3104 unsigned int sh_type
,
3105 const unsigned char* prelocs
,
3107 Output_section
* output_section
,
3108 off_t offset_in_output_section
,
3109 const Relocatable_relocs
* rr
,
3110 unsigned char* view
,
3111 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3112 section_size_type view_size
,
3113 unsigned char* reloc_view
,
3114 section_size_type reloc_view_size
)
3116 gold_assert(sh_type
== elfcpp::SHT_REL
);
3118 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
3123 offset_in_output_section
,
3132 // Return the value to use for a dynamic which requires special
3133 // treatment. This is how we support equality comparisons of function
3134 // pointers across shared library boundaries, as described in the
3135 // processor specific ABI supplement.
3138 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3140 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3141 return this->plt_section()->address() + gsym
->plt_offset();
3144 // Return a string used to fill a code section with nops to take up
3145 // the specified length.
3148 Target_i386::do_code_fill(section_size_type length
) const
3152 // Build a jmp instruction to skip over the bytes.
3153 unsigned char jmp
[5];
3155 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3156 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3157 + std::string(length
- 5, '\0'));
3160 // Nop sequences of various lengths.
3161 const char nop1
[1] = { 0x90 }; // nop
3162 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
3163 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
3164 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
3165 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
3166 0x00 }; // leal 0(%esi,1),%esi
3167 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3169 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3171 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
3172 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3173 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
3174 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
3176 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3177 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3179 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3180 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3182 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3183 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3184 0x00, 0x00, 0x00, 0x00 };
3185 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3186 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3187 0x27, 0x00, 0x00, 0x00,
3189 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3190 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3191 0xbc, 0x27, 0x00, 0x00,
3193 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3194 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3195 0x90, 0x90, 0x90, 0x90,
3198 const char* nops
[16] = {
3200 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3201 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3204 return std::string(nops
[length
], length
);
3207 // Return whether SYM should be treated as a call to a non-split
3208 // function. We don't want that to be true of a call to a
3209 // get_pc_thunk function.
3212 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3214 return (sym
->type() == elfcpp::STT_FUNC
3215 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3218 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3219 // compiled with -fstack-split. The function calls non-stack-split
3220 // code. We have to change the function so that it always ensures
3221 // that it has enough stack space to run some random function.
3224 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3225 section_offset_type fnoffset
,
3226 section_size_type fnsize
,
3227 unsigned char* view
,
3228 section_size_type view_size
,
3230 std::string
* to
) const
3232 // The function starts with a comparison of the stack pointer and a
3233 // field in the TCB. This is followed by a jump.
3236 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3239 // We will call __morestack if the carry flag is set after this
3240 // comparison. We turn the comparison into an stc instruction
3242 view
[fnoffset
] = '\xf9';
3243 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3245 // lea NN(%esp),%ecx
3246 // lea NN(%esp),%edx
3247 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3248 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3251 // This is loading an offset from the stack pointer for a
3252 // comparison. The offset is negative, so we decrease the
3253 // offset by the amount of space we need for the stack. This
3254 // means we will avoid calling __morestack if there happens to
3255 // be plenty of space on the stack already.
3256 unsigned char* pval
= view
+ fnoffset
+ 3;
3257 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3258 val
-= parameters
->options().split_stack_adjust_size();
3259 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3263 if (!object
->has_no_split_stack())
3264 object
->error(_("failed to match split-stack sequence at "
3265 "section %u offset %0zx"),
3266 shndx
, static_cast<size_t>(fnoffset
));
3270 // We have to change the function so that it calls
3271 // __morestack_non_split instead of __morestack. The former will
3272 // allocate additional stack space.
3273 *from
= "__morestack";
3274 *to
= "__morestack_non_split";
3277 // The selector for i386 object files.
3279 class Target_selector_i386
: public Target_selector_freebsd
3282 Target_selector_i386()
3283 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3284 "elf32-i386", "elf32-i386-freebsd")
3288 do_instantiate_target()
3289 { return new Target_i386(); }
3292 Target_selector_i386 target_selector_i386
;
3294 } // End anonymous namespace.