1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
28 #include "parameters.h"
35 #include "copy-relocs.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
48 class Output_data_plt_i386
;
50 // The i386 target class.
51 // TLS info comes from
52 // http://people.redhat.com/drepper/tls.pdf
53 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
55 class Target_i386
: public Target_freebsd
<32, false>
58 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
61 : Target_freebsd
<32, false>(&i386_info
),
62 got_(NULL
), plt_(NULL
), got_plt_(NULL
), global_offset_table_(NULL
),
63 rel_dyn_(NULL
), copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
64 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
67 // Process the relocations to determine unreferenced sections for
68 // garbage collection.
70 gc_process_relocs(Symbol_table
* symtab
,
72 Sized_relobj
<32, false>* object
,
73 unsigned int data_shndx
,
75 const unsigned char* prelocs
,
77 Output_section
* output_section
,
78 bool needs_special_offset_handling
,
79 size_t local_symbol_count
,
80 const unsigned char* plocal_symbols
);
82 // Scan the relocations to look for symbol adjustments.
84 scan_relocs(Symbol_table
* symtab
,
86 Sized_relobj
<32, false>* object
,
87 unsigned int data_shndx
,
89 const unsigned char* prelocs
,
91 Output_section
* output_section
,
92 bool needs_special_offset_handling
,
93 size_t local_symbol_count
,
94 const unsigned char* plocal_symbols
);
96 // Finalize the sections.
98 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
100 // Return the value to use for a dynamic which requires special
103 do_dynsym_value(const Symbol
*) const;
105 // Relocate a section.
107 relocate_section(const Relocate_info
<32, false>*,
108 unsigned int sh_type
,
109 const unsigned char* prelocs
,
111 Output_section
* output_section
,
112 bool needs_special_offset_handling
,
114 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
115 section_size_type view_size
,
116 const Reloc_symbol_changes
*);
118 // Scan the relocs during a relocatable link.
120 scan_relocatable_relocs(Symbol_table
* symtab
,
122 Sized_relobj
<32, false>* object
,
123 unsigned int data_shndx
,
124 unsigned int sh_type
,
125 const unsigned char* prelocs
,
127 Output_section
* output_section
,
128 bool needs_special_offset_handling
,
129 size_t local_symbol_count
,
130 const unsigned char* plocal_symbols
,
131 Relocatable_relocs
*);
133 // Relocate a section during a relocatable link.
135 relocate_for_relocatable(const Relocate_info
<32, false>*,
136 unsigned int sh_type
,
137 const unsigned char* prelocs
,
139 Output_section
* output_section
,
140 off_t offset_in_output_section
,
141 const Relocatable_relocs
*,
143 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
144 section_size_type view_size
,
145 unsigned char* reloc_view
,
146 section_size_type reloc_view_size
);
148 // Return a string used to fill a code section with nops.
150 do_code_fill(section_size_type length
) const;
152 // Return whether SYM is defined by the ABI.
154 do_is_defined_by_abi(const Symbol
* sym
) const
155 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
157 // Return whether a symbol name implies a local label. The UnixWare
158 // 2.1 cc generates temporary symbols that start with .X, so we
159 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
160 // If so, we should move the .X recognition into
161 // Target::do_is_local_label_name.
163 do_is_local_label_name(const char* name
) const
165 if (name
[0] == '.' && name
[1] == 'X')
167 return Target::do_is_local_label_name(name
);
170 // Adjust -fstack-split code which calls non-stack-split code.
172 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
173 section_offset_type fnoffset
, section_size_type fnsize
,
174 unsigned char* view
, section_size_type view_size
,
175 std::string
* from
, std::string
* to
) const;
177 // Return the size of the GOT section.
181 gold_assert(this->got_
!= NULL
);
182 return this->got_
->data_size();
186 // The class which scans relocations.
190 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
191 Sized_relobj
<32, false>* object
,
192 unsigned int data_shndx
,
193 Output_section
* output_section
,
194 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
195 const elfcpp::Sym
<32, false>& lsym
);
198 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
199 Sized_relobj
<32, false>* object
,
200 unsigned int data_shndx
,
201 Output_section
* output_section
,
202 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
206 local_reloc_may_be_function_pointer(Symbol_table
* , Layout
* , Target_i386
* ,
207 Sized_relobj
<32, false>* ,
210 const elfcpp::Rel
<32, false>& ,
212 const elfcpp::Sym
<32, false>&)
216 global_reloc_may_be_function_pointer(Symbol_table
* , Layout
* ,
218 Sized_relobj
<32, false>* ,
221 const elfcpp::Rel
<32, false>& ,
222 unsigned int , Symbol
*)
226 unsupported_reloc_local(Sized_relobj
<32, false>*, unsigned int r_type
);
229 unsupported_reloc_global(Sized_relobj
<32, false>*, unsigned int r_type
,
233 // The class which implements relocation.
238 : skip_call_tls_get_addr_(false),
239 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
244 if (this->skip_call_tls_get_addr_
)
246 // FIXME: This needs to specify the location somehow.
247 gold_error(_("missing expected TLS relocation"));
251 // Return whether the static relocation needs to be applied.
253 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
256 Output_section
* output_section
);
258 // Do a relocation. Return false if the caller should not issue
259 // any warnings about this relocation.
261 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
262 size_t relnum
, const elfcpp::Rel
<32, false>&,
263 unsigned int r_type
, const Sized_symbol
<32>*,
264 const Symbol_value
<32>*,
265 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
269 // Do a TLS relocation.
271 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
272 size_t relnum
, const elfcpp::Rel
<32, false>&,
273 unsigned int r_type
, const Sized_symbol
<32>*,
274 const Symbol_value
<32>*,
275 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
278 // Do a TLS General-Dynamic to Initial-Exec transition.
280 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
281 Output_segment
* tls_segment
,
282 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
283 elfcpp::Elf_types
<32>::Elf_Addr value
,
285 section_size_type view_size
);
287 // Do a TLS General-Dynamic to Local-Exec transition.
289 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
290 Output_segment
* tls_segment
,
291 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
292 elfcpp::Elf_types
<32>::Elf_Addr value
,
294 section_size_type view_size
);
296 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
299 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
300 Output_segment
* tls_segment
,
301 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
302 elfcpp::Elf_types
<32>::Elf_Addr value
,
304 section_size_type view_size
);
306 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
309 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
310 Output_segment
* tls_segment
,
311 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
312 elfcpp::Elf_types
<32>::Elf_Addr value
,
314 section_size_type view_size
);
316 // Do a TLS Local-Dynamic to Local-Exec transition.
318 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
319 Output_segment
* tls_segment
,
320 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
321 elfcpp::Elf_types
<32>::Elf_Addr value
,
323 section_size_type view_size
);
325 // Do a TLS Initial-Exec to Local-Exec transition.
327 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
328 Output_segment
* tls_segment
,
329 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
330 elfcpp::Elf_types
<32>::Elf_Addr value
,
332 section_size_type view_size
);
334 // We need to keep track of which type of local dynamic relocation
335 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
336 enum Local_dynamic_type
343 // This is set if we should skip the next reloc, which should be a
344 // PLT32 reloc against ___tls_get_addr.
345 bool skip_call_tls_get_addr_
;
346 // The type of local dynamic relocation we have seen in the section
347 // being relocated, if any.
348 Local_dynamic_type local_dynamic_type_
;
351 // A class which returns the size required for a relocation type,
352 // used while scanning relocs during a relocatable link.
353 class Relocatable_size_for_reloc
357 get_size_for_reloc(unsigned int, Relobj
*);
360 // Adjust TLS relocation type based on the options and whether this
361 // is a local symbol.
362 static tls::Tls_optimization
363 optimize_tls_reloc(bool is_final
, int r_type
);
365 // Get the GOT section, creating it if necessary.
366 Output_data_got
<32, false>*
367 got_section(Symbol_table
*, Layout
*);
369 // Get the GOT PLT section.
371 got_plt_section() const
373 gold_assert(this->got_plt_
!= NULL
);
374 return this->got_plt_
;
377 // Create a PLT entry for a global symbol.
379 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
381 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
383 define_tls_base_symbol(Symbol_table
*, Layout
*);
385 // Create a GOT entry for the TLS module index.
387 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
388 Sized_relobj
<32, false>* object
);
390 // Get the PLT section.
391 Output_data_plt_i386
*
394 gold_assert(this->plt_
!= NULL
);
398 // Get the dynamic reloc section, creating it if necessary.
400 rel_dyn_section(Layout
*);
402 // Get the section to use for TLS_DESC relocations.
404 rel_tls_desc_section(Layout
*) const;
406 // Add a potential copy relocation.
408 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
409 Sized_relobj
<32, false>* object
,
410 unsigned int shndx
, Output_section
* output_section
,
411 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
413 this->copy_relocs_
.copy_reloc(symtab
, layout
,
414 symtab
->get_sized_symbol
<32>(sym
),
415 object
, shndx
, output_section
, reloc
,
416 this->rel_dyn_section(layout
));
419 // Information about this specific target which we pass to the
420 // general Target structure.
421 static const Target::Target_info i386_info
;
423 // The types of GOT entries needed for this platform.
426 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
427 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
428 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
429 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
430 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
434 Output_data_got
<32, false>* got_
;
436 Output_data_plt_i386
* plt_
;
437 // The GOT PLT section.
438 Output_data_space
* got_plt_
;
439 // The _GLOBAL_OFFSET_TABLE_ symbol.
440 Symbol
* global_offset_table_
;
441 // The dynamic reloc section.
442 Reloc_section
* rel_dyn_
;
443 // Relocs saved to avoid a COPY reloc.
444 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
445 // Space for variables copied with a COPY reloc.
446 Output_data_space
* dynbss_
;
447 // Offset of the GOT entry for the TLS module index.
448 unsigned int got_mod_index_offset_
;
449 // True if the _TLS_MODULE_BASE_ symbol has been defined.
450 bool tls_base_symbol_defined_
;
453 const Target::Target_info
Target_i386::i386_info
=
456 false, // is_big_endian
457 elfcpp::EM_386
, // machine_code
458 false, // has_make_symbol
459 false, // has_resolve
460 true, // has_code_fill
461 true, // is_default_stack_executable
463 "/usr/lib/libc.so.1", // dynamic_linker
464 0x08048000, // default_text_segment_address
465 0x1000, // abi_pagesize (overridable by -z max-page-size)
466 0x1000, // common_pagesize (overridable by -z common-page-size)
467 elfcpp::SHN_UNDEF
, // small_common_shndx
468 elfcpp::SHN_UNDEF
, // large_common_shndx
469 0, // small_common_section_flags
470 0, // large_common_section_flags
471 NULL
, // attributes_section
472 NULL
// attributes_vendor
475 // Get the GOT section, creating it if necessary.
477 Output_data_got
<32, false>*
478 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
480 if (this->got_
== NULL
)
482 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
484 this->got_
= new Output_data_got
<32, false>();
487 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
489 | elfcpp::SHF_WRITE
),
490 this->got_
, false, true, true,
493 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
494 os
= layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
496 | elfcpp::SHF_WRITE
),
497 this->got_plt_
, false, false, false,
500 // The first three entries are reserved.
501 this->got_plt_
->set_current_data_size(3 * 4);
503 // Those bytes can go into the relro segment.
504 layout
->increase_relro(3 * 4);
506 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
507 this->global_offset_table_
=
508 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
509 Symbol_table::PREDEFINED
,
511 0, 0, elfcpp::STT_OBJECT
,
513 elfcpp::STV_HIDDEN
, 0,
520 // Get the dynamic reloc section, creating it if necessary.
522 Target_i386::Reloc_section
*
523 Target_i386::rel_dyn_section(Layout
* layout
)
525 if (this->rel_dyn_
== NULL
)
527 gold_assert(layout
!= NULL
);
528 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
529 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
530 elfcpp::SHF_ALLOC
, this->rel_dyn_
, true,
531 false, false, false);
533 return this->rel_dyn_
;
536 // A class to handle the PLT data.
538 class Output_data_plt_i386
: public Output_section_data
541 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
543 Output_data_plt_i386(Layout
*, Output_data_space
*);
545 // Add an entry to the PLT.
547 add_entry(Symbol
* gsym
);
549 // Return the .rel.plt section data.
552 { return this->rel_
; }
554 // Return where the TLS_DESC relocations should go.
556 rel_tls_desc(Layout
*);
560 do_adjust_output_section(Output_section
* os
);
562 // Write to a map file.
564 do_print_to_mapfile(Mapfile
* mapfile
) const
565 { mapfile
->print_output_data(this, _("** PLT")); }
568 // The size of an entry in the PLT.
569 static const int plt_entry_size
= 16;
571 // The first entry in the PLT for an executable.
572 static unsigned char exec_first_plt_entry
[plt_entry_size
];
574 // The first entry in the PLT for a shared object.
575 static unsigned char dyn_first_plt_entry
[plt_entry_size
];
577 // Other entries in the PLT for an executable.
578 static unsigned char exec_plt_entry
[plt_entry_size
];
580 // Other entries in the PLT for a shared object.
581 static unsigned char dyn_plt_entry
[plt_entry_size
];
583 // Set the final size.
585 set_final_data_size()
586 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
588 // Write out the PLT data.
590 do_write(Output_file
*);
592 // The reloc section.
594 // The TLS_DESC relocations, if necessary. These must follow the
595 // regular PLT relocs.
596 Reloc_section
* tls_desc_rel_
;
597 // The .got.plt section.
598 Output_data_space
* got_plt_
;
599 // The number of PLT entries.
603 // Create the PLT section. The ordinary .got section is an argument,
604 // since we need to refer to the start. We also create our own .got
605 // section just for PLT entries.
607 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
608 Output_data_space
* got_plt
)
609 : Output_section_data(4), tls_desc_rel_(NULL
), got_plt_(got_plt
), count_(0)
611 this->rel_
= new Reloc_section(false);
612 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
613 elfcpp::SHF_ALLOC
, this->rel_
, true,
614 false, false, false);
618 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
620 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
621 // linker, and so do we.
625 // Add an entry to the PLT.
628 Output_data_plt_i386::add_entry(Symbol
* gsym
)
630 gold_assert(!gsym
->has_plt_offset());
632 // Note that when setting the PLT offset we skip the initial
633 // reserved PLT entry.
634 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
638 section_offset_type got_offset
= this->got_plt_
->current_data_size();
640 // Every PLT entry needs a GOT entry which points back to the PLT
641 // entry (this will be changed by the dynamic linker, normally
642 // lazily when the function is called).
643 this->got_plt_
->set_current_data_size(got_offset
+ 4);
645 // Every PLT entry needs a reloc.
646 gsym
->set_needs_dynsym_entry();
647 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
650 // Note that we don't need to save the symbol. The contents of the
651 // PLT are independent of which symbols are used. The symbols only
652 // appear in the relocations.
655 // Return where the TLS_DESC relocations should go, creating it if
656 // necessary. These follow the JUMP_SLOT relocations.
658 Output_data_plt_i386::Reloc_section
*
659 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
661 if (this->tls_desc_rel_
== NULL
)
663 this->tls_desc_rel_
= new Reloc_section(false);
664 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
665 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
666 true, false, false, false);
667 gold_assert(this->tls_desc_rel_
->output_section() ==
668 this->rel_
->output_section());
670 return this->tls_desc_rel_
;
673 // The first entry in the PLT for an executable.
675 unsigned char Output_data_plt_i386::exec_first_plt_entry
[plt_entry_size
] =
677 0xff, 0x35, // pushl contents of memory address
678 0, 0, 0, 0, // replaced with address of .got + 4
679 0xff, 0x25, // jmp indirect
680 0, 0, 0, 0, // replaced with address of .got + 8
684 // The first entry in the PLT for a shared object.
686 unsigned char Output_data_plt_i386::dyn_first_plt_entry
[plt_entry_size
] =
688 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
689 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
693 // Subsequent entries in the PLT for an executable.
695 unsigned char Output_data_plt_i386::exec_plt_entry
[plt_entry_size
] =
697 0xff, 0x25, // jmp indirect
698 0, 0, 0, 0, // replaced with address of symbol in .got
699 0x68, // pushl immediate
700 0, 0, 0, 0, // replaced with offset into relocation table
701 0xe9, // jmp relative
702 0, 0, 0, 0 // replaced with offset to start of .plt
705 // Subsequent entries in the PLT for a shared object.
707 unsigned char Output_data_plt_i386::dyn_plt_entry
[plt_entry_size
] =
709 0xff, 0xa3, // jmp *offset(%ebx)
710 0, 0, 0, 0, // replaced with offset of symbol in .got
711 0x68, // pushl immediate
712 0, 0, 0, 0, // replaced with offset into relocation table
713 0xe9, // jmp relative
714 0, 0, 0, 0 // replaced with offset to start of .plt
717 // Write out the PLT. This uses the hand-coded instructions above,
718 // and adjusts them as needed. This is all specified by the i386 ELF
719 // Processor Supplement.
722 Output_data_plt_i386::do_write(Output_file
* of
)
724 const off_t offset
= this->offset();
725 const section_size_type oview_size
=
726 convert_to_section_size_type(this->data_size());
727 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
729 const off_t got_file_offset
= this->got_plt_
->offset();
730 const section_size_type got_size
=
731 convert_to_section_size_type(this->got_plt_
->data_size());
732 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
735 unsigned char* pov
= oview
;
737 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
738 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
740 if (parameters
->options().output_is_position_independent())
741 memcpy(pov
, dyn_first_plt_entry
, plt_entry_size
);
744 memcpy(pov
, exec_first_plt_entry
, plt_entry_size
);
745 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
746 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
748 pov
+= plt_entry_size
;
750 unsigned char* got_pov
= got_view
;
752 memset(got_pov
, 0, 12);
755 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
757 unsigned int plt_offset
= plt_entry_size
;
758 unsigned int plt_rel_offset
= 0;
759 unsigned int got_offset
= 12;
760 const unsigned int count
= this->count_
;
761 for (unsigned int i
= 0;
764 pov
+= plt_entry_size
,
766 plt_offset
+= plt_entry_size
,
767 plt_rel_offset
+= rel_size
,
770 // Set and adjust the PLT entry itself.
772 if (parameters
->options().output_is_position_independent())
774 memcpy(pov
, dyn_plt_entry
, plt_entry_size
);
775 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
779 memcpy(pov
, exec_plt_entry
, plt_entry_size
);
780 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
785 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
786 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
787 - (plt_offset
+ plt_entry_size
));
789 // Set the entry in the GOT.
790 elfcpp::Swap
<32, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
793 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
794 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
796 of
->write_output_view(offset
, oview_size
, oview
);
797 of
->write_output_view(got_file_offset
, got_size
, got_view
);
800 // Create a PLT entry for a global symbol.
803 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
805 if (gsym
->has_plt_offset())
808 if (this->plt_
== NULL
)
810 // Create the GOT sections first.
811 this->got_section(symtab
, layout
);
813 this->plt_
= new Output_data_plt_i386(layout
, this->got_plt_
);
814 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
816 | elfcpp::SHF_EXECINSTR
),
817 this->plt_
, false, false, false, false);
820 this->plt_
->add_entry(gsym
);
823 // Get the section to use for TLS_DESC relocations.
825 Target_i386::Reloc_section
*
826 Target_i386::rel_tls_desc_section(Layout
* layout
) const
828 return this->plt_section()->rel_tls_desc(layout
);
831 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
834 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
836 if (this->tls_base_symbol_defined_
)
839 Output_segment
* tls_segment
= layout
->tls_segment();
840 if (tls_segment
!= NULL
)
842 bool is_exec
= parameters
->options().output_is_executable();
843 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
844 Symbol_table::PREDEFINED
,
848 elfcpp::STV_HIDDEN
, 0,
850 ? Symbol::SEGMENT_END
851 : Symbol::SEGMENT_START
),
854 this->tls_base_symbol_defined_
= true;
857 // Create a GOT entry for the TLS module index.
860 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
861 Sized_relobj
<32, false>* object
)
863 if (this->got_mod_index_offset_
== -1U)
865 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
866 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
867 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
868 unsigned int got_offset
= got
->add_constant(0);
869 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
871 got
->add_constant(0);
872 this->got_mod_index_offset_
= got_offset
;
874 return this->got_mod_index_offset_
;
877 // Optimize the TLS relocation type based on what we know about the
878 // symbol. IS_FINAL is true if the final address of this symbol is
879 // known at link time.
881 tls::Tls_optimization
882 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
884 // If we are generating a shared library, then we can't do anything
886 if (parameters
->options().shared())
887 return tls::TLSOPT_NONE
;
891 case elfcpp::R_386_TLS_GD
:
892 case elfcpp::R_386_TLS_GOTDESC
:
893 case elfcpp::R_386_TLS_DESC_CALL
:
894 // These are General-Dynamic which permits fully general TLS
895 // access. Since we know that we are generating an executable,
896 // we can convert this to Initial-Exec. If we also know that
897 // this is a local symbol, we can further switch to Local-Exec.
899 return tls::TLSOPT_TO_LE
;
900 return tls::TLSOPT_TO_IE
;
902 case elfcpp::R_386_TLS_LDM
:
903 // This is Local-Dynamic, which refers to a local symbol in the
904 // dynamic TLS block. Since we know that we generating an
905 // executable, we can switch to Local-Exec.
906 return tls::TLSOPT_TO_LE
;
908 case elfcpp::R_386_TLS_LDO_32
:
909 // Another type of Local-Dynamic relocation.
910 return tls::TLSOPT_TO_LE
;
912 case elfcpp::R_386_TLS_IE
:
913 case elfcpp::R_386_TLS_GOTIE
:
914 case elfcpp::R_386_TLS_IE_32
:
915 // These are Initial-Exec relocs which get the thread offset
916 // from the GOT. If we know that we are linking against the
917 // local symbol, we can switch to Local-Exec, which links the
918 // thread offset into the instruction.
920 return tls::TLSOPT_TO_LE
;
921 return tls::TLSOPT_NONE
;
923 case elfcpp::R_386_TLS_LE
:
924 case elfcpp::R_386_TLS_LE_32
:
925 // When we already have Local-Exec, there is nothing further we
927 return tls::TLSOPT_NONE
;
934 // Report an unsupported relocation against a local symbol.
937 Target_i386::Scan::unsupported_reloc_local(Sized_relobj
<32, false>* object
,
940 gold_error(_("%s: unsupported reloc %u against local symbol"),
941 object
->name().c_str(), r_type
);
944 // Scan a relocation for a local symbol.
947 Target_i386::Scan::local(Symbol_table
* symtab
,
950 Sized_relobj
<32, false>* object
,
951 unsigned int data_shndx
,
952 Output_section
* output_section
,
953 const elfcpp::Rel
<32, false>& reloc
,
955 const elfcpp::Sym
<32, false>& lsym
)
959 case elfcpp::R_386_NONE
:
960 case elfcpp::R_386_GNU_VTINHERIT
:
961 case elfcpp::R_386_GNU_VTENTRY
:
964 case elfcpp::R_386_32
:
965 // If building a shared library (or a position-independent
966 // executable), we need to create a dynamic relocation for
967 // this location. The relocation applied at link time will
968 // apply the link-time value, so we flag the location with
969 // an R_386_RELATIVE relocation so the dynamic loader can
970 // relocate it easily.
971 if (parameters
->options().output_is_position_independent())
973 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
974 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
975 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
976 output_section
, data_shndx
,
977 reloc
.get_r_offset());
981 case elfcpp::R_386_16
:
982 case elfcpp::R_386_8
:
983 // If building a shared library (or a position-independent
984 // executable), we need to create a dynamic relocation for
985 // this location. Because the addend needs to remain in the
986 // data section, we need to be careful not to apply this
987 // relocation statically.
988 if (parameters
->options().output_is_position_independent())
990 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
991 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
992 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
993 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
994 data_shndx
, reloc
.get_r_offset());
997 gold_assert(lsym
.get_st_value() == 0);
998 unsigned int shndx
= lsym
.get_st_shndx();
1000 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1003 object
->error(_("section symbol %u has bad shndx %u"),
1006 rel_dyn
->add_local_section(object
, shndx
,
1007 r_type
, output_section
,
1008 data_shndx
, reloc
.get_r_offset());
1013 case elfcpp::R_386_PC32
:
1014 case elfcpp::R_386_PC16
:
1015 case elfcpp::R_386_PC8
:
1018 case elfcpp::R_386_PLT32
:
1019 // Since we know this is a local symbol, we can handle this as a
1023 case elfcpp::R_386_GOTOFF
:
1024 case elfcpp::R_386_GOTPC
:
1025 // We need a GOT section.
1026 target
->got_section(symtab
, layout
);
1029 case elfcpp::R_386_GOT32
:
1031 // The symbol requires a GOT entry.
1032 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1033 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1034 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
1036 // If we are generating a shared object, we need to add a
1037 // dynamic RELATIVE relocation for this symbol's GOT entry.
1038 if (parameters
->options().output_is_position_independent())
1040 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1041 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1042 rel_dyn
->add_local_relative(
1043 object
, r_sym
, elfcpp::R_386_RELATIVE
, got
,
1044 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1050 // These are relocations which should only be seen by the
1051 // dynamic linker, and should never be seen here.
1052 case elfcpp::R_386_COPY
:
1053 case elfcpp::R_386_GLOB_DAT
:
1054 case elfcpp::R_386_JUMP_SLOT
:
1055 case elfcpp::R_386_RELATIVE
:
1056 case elfcpp::R_386_TLS_TPOFF
:
1057 case elfcpp::R_386_TLS_DTPMOD32
:
1058 case elfcpp::R_386_TLS_DTPOFF32
:
1059 case elfcpp::R_386_TLS_TPOFF32
:
1060 case elfcpp::R_386_TLS_DESC
:
1061 gold_error(_("%s: unexpected reloc %u in object file"),
1062 object
->name().c_str(), r_type
);
1065 // These are initial TLS relocs, which are expected when
1067 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1068 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1069 case elfcpp::R_386_TLS_DESC_CALL
:
1070 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1071 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1072 case elfcpp::R_386_TLS_IE
: // Initial-exec
1073 case elfcpp::R_386_TLS_IE_32
:
1074 case elfcpp::R_386_TLS_GOTIE
:
1075 case elfcpp::R_386_TLS_LE
: // Local-exec
1076 case elfcpp::R_386_TLS_LE_32
:
1078 bool output_is_shared
= parameters
->options().shared();
1079 const tls::Tls_optimization optimized_type
1080 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1083 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1084 if (optimized_type
== tls::TLSOPT_NONE
)
1086 // Create a pair of GOT entries for the module index and
1087 // dtv-relative offset.
1088 Output_data_got
<32, false>* got
1089 = target
->got_section(symtab
, layout
);
1090 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1091 unsigned int shndx
= lsym
.get_st_shndx();
1093 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1095 object
->error(_("local symbol %u has bad shndx %u"),
1098 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1100 target
->rel_dyn_section(layout
),
1101 elfcpp::R_386_TLS_DTPMOD32
, 0);
1103 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1104 unsupported_reloc_local(object
, r_type
);
1107 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1108 target
->define_tls_base_symbol(symtab
, layout
);
1109 if (optimized_type
== tls::TLSOPT_NONE
)
1111 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1112 Output_data_got
<32, false>* got
1113 = target
->got_section(symtab
, layout
);
1114 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1115 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1117 unsigned int got_offset
= got
->add_constant(0);
1118 // The local symbol value is stored in the second
1120 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1121 // That set the GOT offset of the local symbol to
1122 // point to the second entry, but we want it to
1123 // point to the first.
1124 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1126 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1127 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1130 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1131 unsupported_reloc_local(object
, r_type
);
1134 case elfcpp::R_386_TLS_DESC_CALL
:
1137 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1138 if (optimized_type
== tls::TLSOPT_NONE
)
1140 // Create a GOT entry for the module index.
1141 target
->got_mod_index_entry(symtab
, layout
, object
);
1143 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1144 unsupported_reloc_local(object
, r_type
);
1147 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1150 case elfcpp::R_386_TLS_IE
: // Initial-exec
1151 case elfcpp::R_386_TLS_IE_32
:
1152 case elfcpp::R_386_TLS_GOTIE
:
1153 layout
->set_has_static_tls();
1154 if (optimized_type
== tls::TLSOPT_NONE
)
1156 // For the R_386_TLS_IE relocation, we need to create a
1157 // dynamic relocation when building a shared library.
1158 if (r_type
== elfcpp::R_386_TLS_IE
1159 && parameters
->options().shared())
1161 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1163 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1164 rel_dyn
->add_local_relative(object
, r_sym
,
1165 elfcpp::R_386_RELATIVE
,
1166 output_section
, data_shndx
,
1167 reloc
.get_r_offset());
1169 // Create a GOT entry for the tp-relative offset.
1170 Output_data_got
<32, false>* got
1171 = target
->got_section(symtab
, layout
);
1172 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1173 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1174 ? elfcpp::R_386_TLS_TPOFF32
1175 : elfcpp::R_386_TLS_TPOFF
);
1176 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1177 ? GOT_TYPE_TLS_OFFSET
1178 : GOT_TYPE_TLS_NOFFSET
);
1179 got
->add_local_with_rel(object
, r_sym
, got_type
,
1180 target
->rel_dyn_section(layout
),
1183 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1184 unsupported_reloc_local(object
, r_type
);
1187 case elfcpp::R_386_TLS_LE
: // Local-exec
1188 case elfcpp::R_386_TLS_LE_32
:
1189 layout
->set_has_static_tls();
1190 if (output_is_shared
)
1192 // We need to create a dynamic relocation.
1193 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1194 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1195 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1196 ? elfcpp::R_386_TLS_TPOFF32
1197 : elfcpp::R_386_TLS_TPOFF
);
1198 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1199 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1200 data_shndx
, reloc
.get_r_offset());
1210 case elfcpp::R_386_32PLT
:
1211 case elfcpp::R_386_TLS_GD_32
:
1212 case elfcpp::R_386_TLS_GD_PUSH
:
1213 case elfcpp::R_386_TLS_GD_CALL
:
1214 case elfcpp::R_386_TLS_GD_POP
:
1215 case elfcpp::R_386_TLS_LDM_32
:
1216 case elfcpp::R_386_TLS_LDM_PUSH
:
1217 case elfcpp::R_386_TLS_LDM_CALL
:
1218 case elfcpp::R_386_TLS_LDM_POP
:
1219 case elfcpp::R_386_USED_BY_INTEL_200
:
1221 unsupported_reloc_local(object
, r_type
);
1226 // Report an unsupported relocation against a global symbol.
1229 Target_i386::Scan::unsupported_reloc_global(Sized_relobj
<32, false>* object
,
1230 unsigned int r_type
,
1233 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1234 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1237 // Scan a relocation for a global symbol.
1240 Target_i386::Scan::global(Symbol_table
* symtab
,
1242 Target_i386
* target
,
1243 Sized_relobj
<32, false>* object
,
1244 unsigned int data_shndx
,
1245 Output_section
* output_section
,
1246 const elfcpp::Rel
<32, false>& reloc
,
1247 unsigned int r_type
,
1252 case elfcpp::R_386_NONE
:
1253 case elfcpp::R_386_GNU_VTINHERIT
:
1254 case elfcpp::R_386_GNU_VTENTRY
:
1257 case elfcpp::R_386_32
:
1258 case elfcpp::R_386_16
:
1259 case elfcpp::R_386_8
:
1261 // Make a PLT entry if necessary.
1262 if (gsym
->needs_plt_entry())
1264 target
->make_plt_entry(symtab
, layout
, gsym
);
1265 // Since this is not a PC-relative relocation, we may be
1266 // taking the address of a function. In that case we need to
1267 // set the entry in the dynamic symbol table to the address of
1269 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1270 gsym
->set_needs_dynsym_value();
1272 // Make a dynamic relocation if necessary.
1273 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1275 if (gsym
->may_need_copy_reloc())
1277 target
->copy_reloc(symtab
, layout
, object
,
1278 data_shndx
, output_section
, gsym
, reloc
);
1280 else if (r_type
== elfcpp::R_386_32
1281 && gsym
->can_use_relative_reloc(false))
1283 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1284 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1285 output_section
, object
,
1286 data_shndx
, reloc
.get_r_offset());
1290 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1291 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1292 data_shndx
, reloc
.get_r_offset());
1298 case elfcpp::R_386_PC32
:
1299 case elfcpp::R_386_PC16
:
1300 case elfcpp::R_386_PC8
:
1302 // Make a PLT entry if necessary.
1303 if (gsym
->needs_plt_entry())
1305 // These relocations are used for function calls only in
1306 // non-PIC code. For a 32-bit relocation in a shared library,
1307 // we'll need a text relocation anyway, so we can skip the
1308 // PLT entry and let the dynamic linker bind the call directly
1309 // to the target. For smaller relocations, we should use a
1310 // PLT entry to ensure that the call can reach.
1311 if (!parameters
->options().shared()
1312 || r_type
!= elfcpp::R_386_PC32
)
1313 target
->make_plt_entry(symtab
, layout
, gsym
);
1315 // Make a dynamic relocation if necessary.
1316 int flags
= Symbol::NON_PIC_REF
;
1317 if (gsym
->is_func())
1318 flags
|= Symbol::FUNCTION_CALL
;
1319 if (gsym
->needs_dynamic_reloc(flags
))
1321 if (gsym
->may_need_copy_reloc())
1323 target
->copy_reloc(symtab
, layout
, object
,
1324 data_shndx
, output_section
, gsym
, reloc
);
1328 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1329 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1330 data_shndx
, reloc
.get_r_offset());
1336 case elfcpp::R_386_GOT32
:
1338 // The symbol requires a GOT entry.
1339 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1340 if (gsym
->final_value_is_known())
1341 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1344 // If this symbol is not fully resolved, we need to add a
1345 // GOT entry with a dynamic relocation.
1346 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1347 if (gsym
->is_from_dynobj()
1348 || gsym
->is_undefined()
1349 || gsym
->is_preemptible())
1350 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
1351 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
1354 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1355 rel_dyn
->add_global_relative(
1356 gsym
, elfcpp::R_386_RELATIVE
, got
,
1357 gsym
->got_offset(GOT_TYPE_STANDARD
));
1363 case elfcpp::R_386_PLT32
:
1364 // If the symbol is fully resolved, this is just a PC32 reloc.
1365 // Otherwise we need a PLT entry.
1366 if (gsym
->final_value_is_known())
1368 // If building a shared library, we can also skip the PLT entry
1369 // if the symbol is defined in the output file and is protected
1371 if (gsym
->is_defined()
1372 && !gsym
->is_from_dynobj()
1373 && !gsym
->is_preemptible())
1375 target
->make_plt_entry(symtab
, layout
, gsym
);
1378 case elfcpp::R_386_GOTOFF
:
1379 case elfcpp::R_386_GOTPC
:
1380 // We need a GOT section.
1381 target
->got_section(symtab
, layout
);
1384 // These are relocations which should only be seen by the
1385 // dynamic linker, and should never be seen here.
1386 case elfcpp::R_386_COPY
:
1387 case elfcpp::R_386_GLOB_DAT
:
1388 case elfcpp::R_386_JUMP_SLOT
:
1389 case elfcpp::R_386_RELATIVE
:
1390 case elfcpp::R_386_TLS_TPOFF
:
1391 case elfcpp::R_386_TLS_DTPMOD32
:
1392 case elfcpp::R_386_TLS_DTPOFF32
:
1393 case elfcpp::R_386_TLS_TPOFF32
:
1394 case elfcpp::R_386_TLS_DESC
:
1395 gold_error(_("%s: unexpected reloc %u in object file"),
1396 object
->name().c_str(), r_type
);
1399 // These are initial tls relocs, which are expected when
1401 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1402 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1403 case elfcpp::R_386_TLS_DESC_CALL
:
1404 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1405 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1406 case elfcpp::R_386_TLS_IE
: // Initial-exec
1407 case elfcpp::R_386_TLS_IE_32
:
1408 case elfcpp::R_386_TLS_GOTIE
:
1409 case elfcpp::R_386_TLS_LE
: // Local-exec
1410 case elfcpp::R_386_TLS_LE_32
:
1412 const bool is_final
= gsym
->final_value_is_known();
1413 const tls::Tls_optimization optimized_type
1414 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1417 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1418 if (optimized_type
== tls::TLSOPT_NONE
)
1420 // Create a pair of GOT entries for the module index and
1421 // dtv-relative offset.
1422 Output_data_got
<32, false>* got
1423 = target
->got_section(symtab
, layout
);
1424 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
1425 target
->rel_dyn_section(layout
),
1426 elfcpp::R_386_TLS_DTPMOD32
,
1427 elfcpp::R_386_TLS_DTPOFF32
);
1429 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1431 // Create a GOT entry for the tp-relative offset.
1432 Output_data_got
<32, false>* got
1433 = target
->got_section(symtab
, layout
);
1434 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1435 target
->rel_dyn_section(layout
),
1436 elfcpp::R_386_TLS_TPOFF
);
1438 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1439 unsupported_reloc_global(object
, r_type
, gsym
);
1442 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
1443 target
->define_tls_base_symbol(symtab
, layout
);
1444 if (optimized_type
== tls::TLSOPT_NONE
)
1446 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1447 Output_data_got
<32, false>* got
1448 = target
->got_section(symtab
, layout
);
1449 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1450 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1451 elfcpp::R_386_TLS_DESC
, 0);
1453 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1455 // Create a GOT entry for the tp-relative offset.
1456 Output_data_got
<32, false>* got
1457 = target
->got_section(symtab
, layout
);
1458 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
1459 target
->rel_dyn_section(layout
),
1460 elfcpp::R_386_TLS_TPOFF
);
1462 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1463 unsupported_reloc_global(object
, r_type
, gsym
);
1466 case elfcpp::R_386_TLS_DESC_CALL
:
1469 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1470 if (optimized_type
== tls::TLSOPT_NONE
)
1472 // Create a GOT entry for the module index.
1473 target
->got_mod_index_entry(symtab
, layout
, object
);
1475 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1476 unsupported_reloc_global(object
, r_type
, gsym
);
1479 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1482 case elfcpp::R_386_TLS_IE
: // Initial-exec
1483 case elfcpp::R_386_TLS_IE_32
:
1484 case elfcpp::R_386_TLS_GOTIE
:
1485 layout
->set_has_static_tls();
1486 if (optimized_type
== tls::TLSOPT_NONE
)
1488 // For the R_386_TLS_IE relocation, we need to create a
1489 // dynamic relocation when building a shared library.
1490 if (r_type
== elfcpp::R_386_TLS_IE
1491 && parameters
->options().shared())
1493 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1494 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
1495 output_section
, object
,
1497 reloc
.get_r_offset());
1499 // Create a GOT entry for the tp-relative offset.
1500 Output_data_got
<32, false>* got
1501 = target
->got_section(symtab
, layout
);
1502 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1503 ? elfcpp::R_386_TLS_TPOFF32
1504 : elfcpp::R_386_TLS_TPOFF
);
1505 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1506 ? GOT_TYPE_TLS_OFFSET
1507 : GOT_TYPE_TLS_NOFFSET
);
1508 got
->add_global_with_rel(gsym
, got_type
,
1509 target
->rel_dyn_section(layout
),
1512 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1513 unsupported_reloc_global(object
, r_type
, gsym
);
1516 case elfcpp::R_386_TLS_LE
: // Local-exec
1517 case elfcpp::R_386_TLS_LE_32
:
1518 layout
->set_has_static_tls();
1519 if (parameters
->options().shared())
1521 // We need to create a dynamic relocation.
1522 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1523 ? elfcpp::R_386_TLS_TPOFF32
1524 : elfcpp::R_386_TLS_TPOFF
);
1525 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1526 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
1527 data_shndx
, reloc
.get_r_offset());
1537 case elfcpp::R_386_32PLT
:
1538 case elfcpp::R_386_TLS_GD_32
:
1539 case elfcpp::R_386_TLS_GD_PUSH
:
1540 case elfcpp::R_386_TLS_GD_CALL
:
1541 case elfcpp::R_386_TLS_GD_POP
:
1542 case elfcpp::R_386_TLS_LDM_32
:
1543 case elfcpp::R_386_TLS_LDM_PUSH
:
1544 case elfcpp::R_386_TLS_LDM_CALL
:
1545 case elfcpp::R_386_TLS_LDM_POP
:
1546 case elfcpp::R_386_USED_BY_INTEL_200
:
1548 unsupported_reloc_global(object
, r_type
, gsym
);
1553 // Process relocations for gc.
1556 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
1558 Sized_relobj
<32, false>* object
,
1559 unsigned int data_shndx
,
1561 const unsigned char* prelocs
,
1563 Output_section
* output_section
,
1564 bool needs_special_offset_handling
,
1565 size_t local_symbol_count
,
1566 const unsigned char* plocal_symbols
)
1568 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1578 needs_special_offset_handling
,
1583 // Scan relocations for a section.
1586 Target_i386::scan_relocs(Symbol_table
* symtab
,
1588 Sized_relobj
<32, false>* object
,
1589 unsigned int data_shndx
,
1590 unsigned int sh_type
,
1591 const unsigned char* prelocs
,
1593 Output_section
* output_section
,
1594 bool needs_special_offset_handling
,
1595 size_t local_symbol_count
,
1596 const unsigned char* plocal_symbols
)
1598 if (sh_type
== elfcpp::SHT_RELA
)
1600 gold_error(_("%s: unsupported RELA reloc section"),
1601 object
->name().c_str());
1605 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
1615 needs_special_offset_handling
,
1620 // Finalize the sections.
1623 Target_i386::do_finalize_sections(
1625 const Input_objects
*,
1626 Symbol_table
* symtab
)
1628 const Reloc_section
* rel_plt
= (this->plt_
== NULL
1630 : this->plt_
->rel_plt());
1631 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
1632 this->rel_dyn_
, true, false);
1634 // Emit any relocs we saved in an attempt to avoid generating COPY
1636 if (this->copy_relocs_
.any_saved_relocs())
1637 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
1639 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1640 // the .got.plt section.
1641 Symbol
* sym
= this->global_offset_table_
;
1644 uint32_t data_size
= this->got_plt_
->current_data_size();
1645 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
1649 // Return whether a direct absolute static relocation needs to be applied.
1650 // In cases where Scan::local() or Scan::global() has created
1651 // a dynamic relocation other than R_386_RELATIVE, the addend
1652 // of the relocation is carried in the data, and we must not
1653 // apply the static relocation.
1656 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1659 Output_section
* output_section
)
1661 // If the output section is not allocated, then we didn't call
1662 // scan_relocs, we didn't create a dynamic reloc, and we must apply
1664 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
1667 // For local symbols, we will have created a non-RELATIVE dynamic
1668 // relocation only if (a) the output is position independent,
1669 // (b) the relocation is absolute (not pc- or segment-relative), and
1670 // (c) the relocation is not 32 bits wide.
1672 return !(parameters
->options().output_is_position_independent()
1673 && (ref_flags
& Symbol::ABSOLUTE_REF
)
1676 // For global symbols, we use the same helper routines used in the
1677 // scan pass. If we did not create a dynamic relocation, or if we
1678 // created a RELATIVE dynamic relocation, we should apply the static
1680 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
1681 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
1682 && gsym
->can_use_relative_reloc(ref_flags
1683 & Symbol::FUNCTION_CALL
);
1684 return !has_dyn
|| is_rel
;
1687 // Perform a relocation.
1690 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
1691 Target_i386
* target
,
1692 Output_section
*output_section
,
1694 const elfcpp::Rel
<32, false>& rel
,
1695 unsigned int r_type
,
1696 const Sized_symbol
<32>* gsym
,
1697 const Symbol_value
<32>* psymval
,
1698 unsigned char* view
,
1699 elfcpp::Elf_types
<32>::Elf_Addr address
,
1700 section_size_type view_size
)
1702 if (this->skip_call_tls_get_addr_
)
1704 if ((r_type
!= elfcpp::R_386_PLT32
1705 && r_type
!= elfcpp::R_386_PC32
)
1707 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
1708 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1709 _("missing expected TLS relocation"));
1712 this->skip_call_tls_get_addr_
= false;
1717 // Pick the value to use for symbols defined in shared objects.
1718 Symbol_value
<32> symval
;
1720 && gsym
->use_plt_offset(r_type
== elfcpp::R_386_PC8
1721 || r_type
== elfcpp::R_386_PC16
1722 || r_type
== elfcpp::R_386_PC32
))
1724 symval
.set_output_value(target
->plt_section()->address()
1725 + gsym
->plt_offset());
1729 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1731 // Get the GOT offset if needed.
1732 // The GOT pointer points to the end of the GOT section.
1733 // We need to subtract the size of the GOT section to get
1734 // the actual offset to use in the relocation.
1735 bool have_got_offset
= false;
1736 unsigned int got_offset
= 0;
1739 case elfcpp::R_386_GOT32
:
1742 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1743 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
1744 - target
->got_size());
1748 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1749 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1750 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1751 - target
->got_size());
1753 have_got_offset
= true;
1762 case elfcpp::R_386_NONE
:
1763 case elfcpp::R_386_GNU_VTINHERIT
:
1764 case elfcpp::R_386_GNU_VTENTRY
:
1767 case elfcpp::R_386_32
:
1768 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
1770 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
1773 case elfcpp::R_386_PC32
:
1775 int ref_flags
= Symbol::NON_PIC_REF
;
1776 if (gsym
!= NULL
&& gsym
->is_func())
1777 ref_flags
|= Symbol::FUNCTION_CALL
;
1778 if (should_apply_static_reloc(gsym
, ref_flags
, true, output_section
))
1779 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1783 case elfcpp::R_386_16
:
1784 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
1786 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
1789 case elfcpp::R_386_PC16
:
1791 int ref_flags
= Symbol::NON_PIC_REF
;
1792 if (gsym
!= NULL
&& gsym
->is_func())
1793 ref_flags
|= Symbol::FUNCTION_CALL
;
1794 if (should_apply_static_reloc(gsym
, ref_flags
, false, output_section
))
1795 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
1799 case elfcpp::R_386_8
:
1800 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
1802 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
1805 case elfcpp::R_386_PC8
:
1807 int ref_flags
= Symbol::NON_PIC_REF
;
1808 if (gsym
!= NULL
&& gsym
->is_func())
1809 ref_flags
|= Symbol::FUNCTION_CALL
;
1810 if (should_apply_static_reloc(gsym
, ref_flags
, false,
1812 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
1816 case elfcpp::R_386_PLT32
:
1817 gold_assert(gsym
== NULL
1818 || gsym
->has_plt_offset()
1819 || gsym
->final_value_is_known()
1820 || (gsym
->is_defined()
1821 && !gsym
->is_from_dynobj()
1822 && !gsym
->is_preemptible()));
1823 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
1826 case elfcpp::R_386_GOT32
:
1827 gold_assert(have_got_offset
);
1828 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1831 case elfcpp::R_386_GOTOFF
:
1833 elfcpp::Elf_types
<32>::Elf_Addr value
;
1834 value
= (psymval
->value(object
, 0)
1835 - target
->got_plt_section()->address());
1836 Relocate_functions
<32, false>::rel32(view
, value
);
1840 case elfcpp::R_386_GOTPC
:
1842 elfcpp::Elf_types
<32>::Elf_Addr value
;
1843 value
= target
->got_plt_section()->address();
1844 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
1848 case elfcpp::R_386_COPY
:
1849 case elfcpp::R_386_GLOB_DAT
:
1850 case elfcpp::R_386_JUMP_SLOT
:
1851 case elfcpp::R_386_RELATIVE
:
1852 // These are outstanding tls relocs, which are unexpected when
1854 case elfcpp::R_386_TLS_TPOFF
:
1855 case elfcpp::R_386_TLS_DTPMOD32
:
1856 case elfcpp::R_386_TLS_DTPOFF32
:
1857 case elfcpp::R_386_TLS_TPOFF32
:
1858 case elfcpp::R_386_TLS_DESC
:
1859 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1860 _("unexpected reloc %u in object file"),
1864 // These are initial tls relocs, which are expected when
1866 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1867 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1868 case elfcpp::R_386_TLS_DESC_CALL
:
1869 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1870 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1871 case elfcpp::R_386_TLS_IE
: // Initial-exec
1872 case elfcpp::R_386_TLS_IE_32
:
1873 case elfcpp::R_386_TLS_GOTIE
:
1874 case elfcpp::R_386_TLS_LE
: // Local-exec
1875 case elfcpp::R_386_TLS_LE_32
:
1876 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
1877 view
, address
, view_size
);
1880 case elfcpp::R_386_32PLT
:
1881 case elfcpp::R_386_TLS_GD_32
:
1882 case elfcpp::R_386_TLS_GD_PUSH
:
1883 case elfcpp::R_386_TLS_GD_CALL
:
1884 case elfcpp::R_386_TLS_GD_POP
:
1885 case elfcpp::R_386_TLS_LDM_32
:
1886 case elfcpp::R_386_TLS_LDM_PUSH
:
1887 case elfcpp::R_386_TLS_LDM_CALL
:
1888 case elfcpp::R_386_TLS_LDM_POP
:
1889 case elfcpp::R_386_USED_BY_INTEL_200
:
1891 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1892 _("unsupported reloc %u"),
1900 // Perform a TLS relocation.
1903 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
1904 Target_i386
* target
,
1906 const elfcpp::Rel
<32, false>& rel
,
1907 unsigned int r_type
,
1908 const Sized_symbol
<32>* gsym
,
1909 const Symbol_value
<32>* psymval
,
1910 unsigned char* view
,
1911 elfcpp::Elf_types
<32>::Elf_Addr
,
1912 section_size_type view_size
)
1914 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1916 const Sized_relobj
<32, false>* object
= relinfo
->object
;
1918 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
1920 const bool is_final
= (gsym
== NULL
1921 ? !parameters
->options().shared()
1922 : gsym
->final_value_is_known());
1923 const tls::Tls_optimization optimized_type
1924 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
1927 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1928 if (optimized_type
== tls::TLSOPT_TO_LE
)
1930 gold_assert(tls_segment
!= NULL
);
1931 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1932 rel
, r_type
, value
, view
,
1938 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1939 ? GOT_TYPE_TLS_NOFFSET
1940 : GOT_TYPE_TLS_PAIR
);
1941 unsigned int got_offset
;
1944 gold_assert(gsym
->has_got_offset(got_type
));
1945 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1949 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1950 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
1951 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
1952 - target
->got_size());
1954 if (optimized_type
== tls::TLSOPT_TO_IE
)
1956 gold_assert(tls_segment
!= NULL
);
1957 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
1958 got_offset
, view
, view_size
);
1961 else if (optimized_type
== tls::TLSOPT_NONE
)
1963 // Relocate the field with the offset of the pair of GOT
1965 Relocate_functions
<32, false>::rel32(view
, got_offset
);
1969 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1970 _("unsupported reloc %u"),
1974 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1975 case elfcpp::R_386_TLS_DESC_CALL
:
1976 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
1977 if (optimized_type
== tls::TLSOPT_TO_LE
)
1979 gold_assert(tls_segment
!= NULL
);
1980 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
1981 rel
, r_type
, value
, view
,
1987 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
1988 ? GOT_TYPE_TLS_NOFFSET
1989 : GOT_TYPE_TLS_DESC
);
1990 unsigned int got_offset
;
1993 gold_assert(gsym
->has_got_offset(got_type
));
1994 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
1998 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
1999 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2000 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2001 - target
->got_size());
2003 if (optimized_type
== tls::TLSOPT_TO_IE
)
2005 gold_assert(tls_segment
!= NULL
);
2006 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2007 got_offset
, view
, view_size
);
2010 else if (optimized_type
== tls::TLSOPT_NONE
)
2012 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2014 // Relocate the field with the offset of the pair of GOT
2016 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2021 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2022 _("unsupported reloc %u"),
2026 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2027 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2029 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2030 _("both SUN and GNU model "
2031 "TLS relocations"));
2034 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2035 if (optimized_type
== tls::TLSOPT_TO_LE
)
2037 gold_assert(tls_segment
!= NULL
);
2038 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2039 value
, view
, view_size
);
2042 else if (optimized_type
== tls::TLSOPT_NONE
)
2044 // Relocate the field with the offset of the GOT entry for
2045 // the module index.
2046 unsigned int got_offset
;
2047 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2048 - target
->got_size());
2049 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2052 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2053 _("unsupported reloc %u"),
2057 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2058 if (optimized_type
== tls::TLSOPT_TO_LE
)
2060 // This reloc can appear in debugging sections, in which
2061 // case we must not convert to local-exec. We decide what
2062 // to do based on whether the section is marked as
2063 // containing executable code. That is what the GNU linker
2065 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
2066 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
2068 gold_assert(tls_segment
!= NULL
);
2069 value
-= tls_segment
->memsz();
2072 Relocate_functions
<32, false>::rel32(view
, value
);
2075 case elfcpp::R_386_TLS_IE
: // Initial-exec
2076 case elfcpp::R_386_TLS_GOTIE
:
2077 case elfcpp::R_386_TLS_IE_32
:
2078 if (optimized_type
== tls::TLSOPT_TO_LE
)
2080 gold_assert(tls_segment
!= NULL
);
2081 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2082 rel
, r_type
, value
, view
,
2086 else if (optimized_type
== tls::TLSOPT_NONE
)
2088 // Relocate the field with the offset of the GOT entry for
2089 // the tp-relative offset of the symbol.
2090 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2091 ? GOT_TYPE_TLS_OFFSET
2092 : GOT_TYPE_TLS_NOFFSET
);
2093 unsigned int got_offset
;
2096 gold_assert(gsym
->has_got_offset(got_type
));
2097 got_offset
= gsym
->got_offset(got_type
);
2101 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2102 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2103 got_offset
= object
->local_got_offset(r_sym
, got_type
);
2105 // For the R_386_TLS_IE relocation, we need to apply the
2106 // absolute address of the GOT entry.
2107 if (r_type
== elfcpp::R_386_TLS_IE
)
2108 got_offset
+= target
->got_plt_section()->address();
2109 // All GOT offsets are relative to the end of the GOT.
2110 got_offset
-= target
->got_size();
2111 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2114 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2115 _("unsupported reloc %u"),
2119 case elfcpp::R_386_TLS_LE
: // Local-exec
2120 // If we're creating a shared library, a dynamic relocation will
2121 // have been created for this location, so do not apply it now.
2122 if (!parameters
->options().shared())
2124 gold_assert(tls_segment
!= NULL
);
2125 value
-= tls_segment
->memsz();
2126 Relocate_functions
<32, false>::rel32(view
, value
);
2130 case elfcpp::R_386_TLS_LE_32
:
2131 // If we're creating a shared library, a dynamic relocation will
2132 // have been created for this location, so do not apply it now.
2133 if (!parameters
->options().shared())
2135 gold_assert(tls_segment
!= NULL
);
2136 value
= tls_segment
->memsz() - value
;
2137 Relocate_functions
<32, false>::rel32(view
, value
);
2143 // Do a relocation in which we convert a TLS General-Dynamic to a
2147 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
2149 Output_segment
* tls_segment
,
2150 const elfcpp::Rel
<32, false>& rel
,
2152 elfcpp::Elf_types
<32>::Elf_Addr value
,
2153 unsigned char* view
,
2154 section_size_type view_size
)
2156 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2157 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2158 // leal foo(%reg),%eax; call ___tls_get_addr
2159 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2161 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2162 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2164 unsigned char op1
= view
[-1];
2165 unsigned char op2
= view
[-2];
2167 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2168 op2
== 0x8d || op2
== 0x04);
2169 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2175 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2176 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2177 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2178 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2179 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2183 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2184 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2185 if (rel
.get_r_offset() + 9 < view_size
2188 // There is a trailing nop. Use the size byte subl.
2189 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2194 // Use the five byte subl.
2195 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2199 value
= tls_segment
->memsz() - value
;
2200 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2202 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2204 this->skip_call_tls_get_addr_
= true;
2207 // Do a relocation in which we convert a TLS General-Dynamic to an
2211 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
2214 const elfcpp::Rel
<32, false>& rel
,
2216 elfcpp::Elf_types
<32>::Elf_Addr value
,
2217 unsigned char* view
,
2218 section_size_type view_size
)
2220 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2221 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2223 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2224 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2226 unsigned char op1
= view
[-1];
2227 unsigned char op2
= view
[-2];
2229 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2230 op2
== 0x8d || op2
== 0x04);
2231 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2235 // FIXME: For now, support only the first (SIB) form.
2236 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
2240 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
2241 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
2242 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2243 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
2244 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2248 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2249 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
2250 if (rel
.get_r_offset() + 9 < view_size
2253 // FIXME: This is not the right instruction sequence.
2254 // There is a trailing nop. Use the size byte subl.
2255 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2260 // FIXME: This is not the right instruction sequence.
2261 // Use the five byte subl.
2262 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2266 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
2268 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2270 this->skip_call_tls_get_addr_
= true;
2273 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2274 // General-Dynamic to a Local-Exec.
2277 Target_i386::Relocate::tls_desc_gd_to_le(
2278 const Relocate_info
<32, false>* relinfo
,
2280 Output_segment
* tls_segment
,
2281 const elfcpp::Rel
<32, false>& rel
,
2282 unsigned int r_type
,
2283 elfcpp::Elf_types
<32>::Elf_Addr value
,
2284 unsigned char* view
,
2285 section_size_type view_size
)
2287 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2289 // leal foo@TLSDESC(%ebx), %eax
2290 // ==> leal foo@NTPOFF, %eax
2291 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2292 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2293 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2294 view
[-2] == 0x8d && view
[-1] == 0x83);
2296 value
-= tls_segment
->memsz();
2297 Relocate_functions
<32, false>::rel32(view
, value
);
2301 // call *foo@TLSCALL(%eax)
2303 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2304 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2305 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2306 view
[0] == 0xff && view
[1] == 0x10);
2312 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2313 // General-Dynamic to an Initial-Exec.
2316 Target_i386::Relocate::tls_desc_gd_to_ie(
2317 const Relocate_info
<32, false>* relinfo
,
2320 const elfcpp::Rel
<32, false>& rel
,
2321 unsigned int r_type
,
2322 elfcpp::Elf_types
<32>::Elf_Addr value
,
2323 unsigned char* view
,
2324 section_size_type view_size
)
2326 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2328 // leal foo@TLSDESC(%ebx), %eax
2329 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2330 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2331 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2332 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2333 view
[-2] == 0x8d && view
[-1] == 0x83);
2335 Relocate_functions
<32, false>::rel32(view
, value
);
2339 // call *foo@TLSCALL(%eax)
2341 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
2342 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
2343 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2344 view
[0] == 0xff && view
[1] == 0x10);
2350 // Do a relocation in which we convert a TLS Local-Dynamic to a
2354 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
2357 const elfcpp::Rel
<32, false>& rel
,
2359 elfcpp::Elf_types
<32>::Elf_Addr
,
2360 unsigned char* view
,
2361 section_size_type view_size
)
2363 // leal foo(%reg), %eax; call ___tls_get_addr
2364 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2366 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2367 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
2369 // FIXME: Does this test really always pass?
2370 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2371 view
[-2] == 0x8d && view
[-1] == 0x83);
2373 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
2375 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2377 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2379 this->skip_call_tls_get_addr_
= true;
2382 // Do a relocation in which we convert a TLS Initial-Exec to a
2386 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
2388 Output_segment
* tls_segment
,
2389 const elfcpp::Rel
<32, false>& rel
,
2390 unsigned int r_type
,
2391 elfcpp::Elf_types
<32>::Elf_Addr value
,
2392 unsigned char* view
,
2393 section_size_type view_size
)
2395 // We have to actually change the instructions, which means that we
2396 // need to examine the opcodes to figure out which instruction we
2398 if (r_type
== elfcpp::R_386_TLS_IE
)
2400 // movl %gs:XX,%eax ==> movl $YY,%eax
2401 // movl %gs:XX,%reg ==> movl $YY,%reg
2402 // addl %gs:XX,%reg ==> addl $YY,%reg
2403 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
2404 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2406 unsigned char op1
= view
[-1];
2409 // movl XX,%eax ==> movl $YY,%eax
2414 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2416 unsigned char op2
= view
[-2];
2419 // movl XX,%reg ==> movl $YY,%reg
2420 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2421 (op1
& 0xc7) == 0x05);
2423 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2425 else if (op2
== 0x03)
2427 // addl XX,%reg ==> addl $YY,%reg
2428 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2429 (op1
& 0xc7) == 0x05);
2431 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2434 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2439 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2440 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2441 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2442 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
2443 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
2445 unsigned char op1
= view
[-1];
2446 unsigned char op2
= view
[-2];
2447 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
2448 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
2451 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2453 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2455 else if (op2
== 0x2b)
2457 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2459 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
2461 else if (op2
== 0x03)
2463 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2465 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
2468 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
2471 value
= tls_segment
->memsz() - value
;
2472 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
2475 Relocate_functions
<32, false>::rel32(view
, value
);
2478 // Relocate section data.
2481 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
2482 unsigned int sh_type
,
2483 const unsigned char* prelocs
,
2485 Output_section
* output_section
,
2486 bool needs_special_offset_handling
,
2487 unsigned char* view
,
2488 elfcpp::Elf_types
<32>::Elf_Addr address
,
2489 section_size_type view_size
,
2490 const Reloc_symbol_changes
* reloc_symbol_changes
)
2492 gold_assert(sh_type
== elfcpp::SHT_REL
);
2494 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
2495 Target_i386::Relocate
>(
2501 needs_special_offset_handling
,
2505 reloc_symbol_changes
);
2508 // Return the size of a relocation while scanning during a relocatable
2512 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2513 unsigned int r_type
,
2518 case elfcpp::R_386_NONE
:
2519 case elfcpp::R_386_GNU_VTINHERIT
:
2520 case elfcpp::R_386_GNU_VTENTRY
:
2521 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2522 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2523 case elfcpp::R_386_TLS_DESC_CALL
:
2524 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2525 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2526 case elfcpp::R_386_TLS_IE
: // Initial-exec
2527 case elfcpp::R_386_TLS_IE_32
:
2528 case elfcpp::R_386_TLS_GOTIE
:
2529 case elfcpp::R_386_TLS_LE
: // Local-exec
2530 case elfcpp::R_386_TLS_LE_32
:
2533 case elfcpp::R_386_32
:
2534 case elfcpp::R_386_PC32
:
2535 case elfcpp::R_386_GOT32
:
2536 case elfcpp::R_386_PLT32
:
2537 case elfcpp::R_386_GOTOFF
:
2538 case elfcpp::R_386_GOTPC
:
2541 case elfcpp::R_386_16
:
2542 case elfcpp::R_386_PC16
:
2545 case elfcpp::R_386_8
:
2546 case elfcpp::R_386_PC8
:
2549 // These are relocations which should only be seen by the
2550 // dynamic linker, and should never be seen here.
2551 case elfcpp::R_386_COPY
:
2552 case elfcpp::R_386_GLOB_DAT
:
2553 case elfcpp::R_386_JUMP_SLOT
:
2554 case elfcpp::R_386_RELATIVE
:
2555 case elfcpp::R_386_TLS_TPOFF
:
2556 case elfcpp::R_386_TLS_DTPMOD32
:
2557 case elfcpp::R_386_TLS_DTPOFF32
:
2558 case elfcpp::R_386_TLS_TPOFF32
:
2559 case elfcpp::R_386_TLS_DESC
:
2560 object
->error(_("unexpected reloc %u in object file"), r_type
);
2563 case elfcpp::R_386_32PLT
:
2564 case elfcpp::R_386_TLS_GD_32
:
2565 case elfcpp::R_386_TLS_GD_PUSH
:
2566 case elfcpp::R_386_TLS_GD_CALL
:
2567 case elfcpp::R_386_TLS_GD_POP
:
2568 case elfcpp::R_386_TLS_LDM_32
:
2569 case elfcpp::R_386_TLS_LDM_PUSH
:
2570 case elfcpp::R_386_TLS_LDM_CALL
:
2571 case elfcpp::R_386_TLS_LDM_POP
:
2572 case elfcpp::R_386_USED_BY_INTEL_200
:
2574 object
->error(_("unsupported reloc %u in object file"), r_type
);
2579 // Scan the relocs during a relocatable link.
2582 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
2584 Sized_relobj
<32, false>* object
,
2585 unsigned int data_shndx
,
2586 unsigned int sh_type
,
2587 const unsigned char* prelocs
,
2589 Output_section
* output_section
,
2590 bool needs_special_offset_handling
,
2591 size_t local_symbol_count
,
2592 const unsigned char* plocal_symbols
,
2593 Relocatable_relocs
* rr
)
2595 gold_assert(sh_type
== elfcpp::SHT_REL
);
2597 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
2598 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2600 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
2601 Scan_relocatable_relocs
>(
2609 needs_special_offset_handling
,
2615 // Relocate a section during a relocatable link.
2618 Target_i386::relocate_for_relocatable(
2619 const Relocate_info
<32, false>* relinfo
,
2620 unsigned int sh_type
,
2621 const unsigned char* prelocs
,
2623 Output_section
* output_section
,
2624 off_t offset_in_output_section
,
2625 const Relocatable_relocs
* rr
,
2626 unsigned char* view
,
2627 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
2628 section_size_type view_size
,
2629 unsigned char* reloc_view
,
2630 section_size_type reloc_view_size
)
2632 gold_assert(sh_type
== elfcpp::SHT_REL
);
2634 gold::relocate_for_relocatable
<32, false, elfcpp::SHT_REL
>(
2639 offset_in_output_section
,
2648 // Return the value to use for a dynamic which requires special
2649 // treatment. This is how we support equality comparisons of function
2650 // pointers across shared library boundaries, as described in the
2651 // processor specific ABI supplement.
2654 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
2656 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2657 return this->plt_section()->address() + gsym
->plt_offset();
2660 // Return a string used to fill a code section with nops to take up
2661 // the specified length.
2664 Target_i386::do_code_fill(section_size_type length
) const
2668 // Build a jmp instruction to skip over the bytes.
2669 unsigned char jmp
[5];
2671 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2672 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2673 + std::string(length
- 5, '\0'));
2676 // Nop sequences of various lengths.
2677 const char nop1
[1] = { 0x90 }; // nop
2678 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2679 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2680 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2681 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2682 0x00 }; // leal 0(%esi,1),%esi
2683 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2685 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2687 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2688 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2689 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2690 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2692 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2693 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2695 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2696 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2698 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2699 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2700 0x00, 0x00, 0x00, 0x00 };
2701 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2702 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2703 0x27, 0x00, 0x00, 0x00,
2705 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2706 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2707 0xbc, 0x27, 0x00, 0x00,
2709 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2710 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2711 0x90, 0x90, 0x90, 0x90,
2714 const char* nops
[16] = {
2716 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2717 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2720 return std::string(nops
[length
], length
);
2723 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2724 // compiled with -fstack-split. The function calls non-stack-split
2725 // code. We have to change the function so that it always ensures
2726 // that it has enough stack space to run some random function.
2729 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
2730 section_offset_type fnoffset
,
2731 section_size_type fnsize
,
2732 unsigned char* view
,
2733 section_size_type view_size
,
2735 std::string
* to
) const
2737 // The function starts with a comparison of the stack pointer and a
2738 // field in the TCB. This is followed by a jump.
2741 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
2744 // We will call __morestack if the carry flag is set after this
2745 // comparison. We turn the comparison into an stc instruction
2747 view
[fnoffset
] = '\xf9';
2748 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
2750 // lea NN(%esp),%ecx
2751 // lea NN(%esp),%edx
2752 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
2753 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
2756 // This is loading an offset from the stack pointer for a
2757 // comparison. The offset is negative, so we decrease the
2758 // offset by the amount of space we need for the stack. This
2759 // means we will avoid calling __morestack if there happens to
2760 // be plenty of space on the stack already.
2761 unsigned char* pval
= view
+ fnoffset
+ 3;
2762 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
2763 val
-= parameters
->options().split_stack_adjust_size();
2764 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
2768 if (!object
->has_no_split_stack())
2769 object
->error(_("failed to match split-stack sequence at "
2770 "section %u offset %0zx"),
2771 shndx
, static_cast<size_t>(fnoffset
));
2775 // We have to change the function so that it calls
2776 // __morestack_non_split instead of __morestack. The former will
2777 // allocate additional stack space.
2778 *from
= "__morestack";
2779 *to
= "__morestack_non_split";
2782 // The selector for i386 object files.
2784 class Target_selector_i386
: public Target_selector_freebsd
2787 Target_selector_i386()
2788 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
2789 "elf32-i386", "elf32-i386-freebsd")
2793 do_instantiate_target()
2794 { return new Target_i386(); }
2797 Target_selector_i386 target_selector_i386
;
2799 } // End anonymous namespace.