1 // x86_64.cc -- x86_64 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_x86_64
;
50 // The x86_64 target class.
52 // http://www.x86-64.org/documentation/abi.pdf
53 // TLS info comes from
54 // http://people.redhat.com/drepper/tls.pdf
55 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
57 class Target_x86_64
: public Target_freebsd
<64, false>
60 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
61 // uses only Elf64_Rela relocation entries with explicit addends."
62 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
65 : Target_freebsd
<64, false>(&x86_64_info
),
66 got_(NULL
), plt_(NULL
), got_plt_(NULL
), global_offset_table_(NULL
),
67 rela_dyn_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
), dynbss_(NULL
),
68 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
71 // Hook for a new output section.
73 do_new_output_section(Output_section
*) const;
75 // Scan the relocations to look for symbol adjustments.
77 gc_process_relocs(Symbol_table
* symtab
,
79 Sized_relobj
<64, false>* object
,
80 unsigned int data_shndx
,
82 const unsigned char* prelocs
,
84 Output_section
* output_section
,
85 bool needs_special_offset_handling
,
86 size_t local_symbol_count
,
87 const unsigned char* plocal_symbols
);
89 // Scan the relocations to look for symbol adjustments.
91 scan_relocs(Symbol_table
* symtab
,
93 Sized_relobj
<64, false>* object
,
94 unsigned int data_shndx
,
96 const unsigned char* prelocs
,
98 Output_section
* output_section
,
99 bool needs_special_offset_handling
,
100 size_t local_symbol_count
,
101 const unsigned char* plocal_symbols
);
103 // Finalize the sections.
105 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
107 // Return the value to use for a dynamic which requires special
110 do_dynsym_value(const Symbol
*) const;
112 // Relocate a section.
114 relocate_section(const Relocate_info
<64, false>*,
115 unsigned int sh_type
,
116 const unsigned char* prelocs
,
118 Output_section
* output_section
,
119 bool needs_special_offset_handling
,
121 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
122 section_size_type view_size
,
123 const Reloc_symbol_changes
*);
125 // Scan the relocs during a relocatable link.
127 scan_relocatable_relocs(Symbol_table
* symtab
,
129 Sized_relobj
<64, false>* object
,
130 unsigned int data_shndx
,
131 unsigned int sh_type
,
132 const unsigned char* prelocs
,
134 Output_section
* output_section
,
135 bool needs_special_offset_handling
,
136 size_t local_symbol_count
,
137 const unsigned char* plocal_symbols
,
138 Relocatable_relocs
*);
140 // Relocate a section during a relocatable link.
142 relocate_for_relocatable(const Relocate_info
<64, false>*,
143 unsigned int sh_type
,
144 const unsigned char* prelocs
,
146 Output_section
* output_section
,
147 off_t offset_in_output_section
,
148 const Relocatable_relocs
*,
150 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
151 section_size_type view_size
,
152 unsigned char* reloc_view
,
153 section_size_type reloc_view_size
);
155 // Return a string used to fill a code section with nops.
157 do_code_fill(section_size_type length
) const;
159 // Return whether SYM is defined by the ABI.
161 do_is_defined_by_abi(const Symbol
* sym
) const
162 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
164 // Adjust -fstack-split code which calls non-stack-split code.
166 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
167 section_offset_type fnoffset
, section_size_type fnsize
,
168 unsigned char* view
, section_size_type view_size
,
169 std::string
* from
, std::string
* to
) const;
171 // Return the size of the GOT section.
175 gold_assert(this->got_
!= NULL
);
176 return this->got_
->data_size();
180 // The class which scans relocations.
185 : issued_non_pic_error_(false)
189 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
190 Sized_relobj
<64, false>* object
,
191 unsigned int data_shndx
,
192 Output_section
* output_section
,
193 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
194 const elfcpp::Sym
<64, false>& lsym
);
197 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
198 Sized_relobj
<64, false>* object
,
199 unsigned int data_shndx
,
200 Output_section
* output_section
,
201 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
206 unsupported_reloc_local(Sized_relobj
<64, false>*, unsigned int r_type
);
209 unsupported_reloc_global(Sized_relobj
<64, false>*, unsigned int r_type
,
213 check_non_pic(Relobj
*, unsigned int r_type
);
215 // Whether we have issued an error about a non-PIC compilation.
216 bool issued_non_pic_error_
;
219 // The class which implements relocation.
224 : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
229 if (this->skip_call_tls_get_addr_
)
231 // FIXME: This needs to specify the location somehow.
232 gold_error(_("missing expected TLS relocation"));
236 // Do a relocation. Return false if the caller should not issue
237 // any warnings about this relocation.
239 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, Output_section
*,
240 size_t relnum
, const elfcpp::Rela
<64, false>&,
241 unsigned int r_type
, const Sized_symbol
<64>*,
242 const Symbol_value
<64>*,
243 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
247 // Do a TLS relocation.
249 relocate_tls(const Relocate_info
<64, false>*, Target_x86_64
*,
250 size_t relnum
, const elfcpp::Rela
<64, false>&,
251 unsigned int r_type
, const Sized_symbol
<64>*,
252 const Symbol_value
<64>*,
253 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
256 // Do a TLS General-Dynamic to Initial-Exec transition.
258 tls_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
259 Output_segment
* tls_segment
,
260 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
261 elfcpp::Elf_types
<64>::Elf_Addr value
,
263 elfcpp::Elf_types
<64>::Elf_Addr
,
264 section_size_type view_size
);
266 // Do a TLS General-Dynamic to Local-Exec transition.
268 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
269 Output_segment
* tls_segment
,
270 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
271 elfcpp::Elf_types
<64>::Elf_Addr value
,
273 section_size_type view_size
);
275 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
277 tls_desc_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
278 Output_segment
* tls_segment
,
279 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
280 elfcpp::Elf_types
<64>::Elf_Addr value
,
282 elfcpp::Elf_types
<64>::Elf_Addr
,
283 section_size_type view_size
);
285 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
287 tls_desc_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
288 Output_segment
* tls_segment
,
289 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
290 elfcpp::Elf_types
<64>::Elf_Addr value
,
292 section_size_type view_size
);
294 // Do a TLS Local-Dynamic to Local-Exec transition.
296 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
297 Output_segment
* tls_segment
,
298 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
299 elfcpp::Elf_types
<64>::Elf_Addr value
,
301 section_size_type view_size
);
303 // Do a TLS Initial-Exec to Local-Exec transition.
305 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
306 Output_segment
* tls_segment
,
307 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
308 elfcpp::Elf_types
<64>::Elf_Addr value
,
310 section_size_type view_size
);
312 // This is set if we should skip the next reloc, which should be a
313 // PLT32 reloc against ___tls_get_addr.
314 bool skip_call_tls_get_addr_
;
316 // This is set if we see a relocation which could load the address
317 // of the TLS block. Whether we see such a relocation determines
318 // how we handle the R_X86_64_DTPOFF32 relocation, which is used
319 // in debugging sections.
320 bool saw_tls_block_reloc_
;
323 // A class which returns the size required for a relocation type,
324 // used while scanning relocs during a relocatable link.
325 class Relocatable_size_for_reloc
329 get_size_for_reloc(unsigned int, Relobj
*);
332 // Adjust TLS relocation type based on the options and whether this
333 // is a local symbol.
334 static tls::Tls_optimization
335 optimize_tls_reloc(bool is_final
, int r_type
);
337 // Get the GOT section, creating it if necessary.
338 Output_data_got
<64, false>*
339 got_section(Symbol_table
*, Layout
*);
341 // Get the GOT PLT section.
343 got_plt_section() const
345 gold_assert(this->got_plt_
!= NULL
);
346 return this->got_plt_
;
349 // Create the PLT section.
351 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
353 // Create a PLT entry for a global symbol.
355 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
357 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
359 define_tls_base_symbol(Symbol_table
*, Layout
*);
361 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
363 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
365 // Create a GOT entry for the TLS module index.
367 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
368 Sized_relobj
<64, false>* object
);
370 // Get the PLT section.
371 Output_data_plt_x86_64
*
374 gold_assert(this->plt_
!= NULL
);
378 // Get the dynamic reloc section, creating it if necessary.
380 rela_dyn_section(Layout
*);
382 // Add a potential copy relocation.
384 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
385 Sized_relobj
<64, false>* object
,
386 unsigned int shndx
, Output_section
* output_section
,
387 Symbol
* sym
, const elfcpp::Rela
<64, false>& reloc
)
389 this->copy_relocs_
.copy_reloc(symtab
, layout
,
390 symtab
->get_sized_symbol
<64>(sym
),
391 object
, shndx
, output_section
,
392 reloc
, this->rela_dyn_section(layout
));
395 // Information about this specific target which we pass to the
396 // general Target structure.
397 static const Target::Target_info x86_64_info
;
401 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
402 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
403 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
404 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
408 Output_data_got
<64, false>* got_
;
410 Output_data_plt_x86_64
* plt_
;
411 // The GOT PLT section.
412 Output_data_space
* got_plt_
;
413 // The _GLOBAL_OFFSET_TABLE_ symbol.
414 Symbol
* global_offset_table_
;
415 // The dynamic reloc section.
416 Reloc_section
* rela_dyn_
;
417 // Relocs saved to avoid a COPY reloc.
418 Copy_relocs
<elfcpp::SHT_RELA
, 64, false> copy_relocs_
;
419 // Space for variables copied with a COPY reloc.
420 Output_data_space
* dynbss_
;
421 // Offset of the GOT entry for the TLS module index.
422 unsigned int got_mod_index_offset_
;
423 // True if the _TLS_MODULE_BASE_ symbol has been defined.
424 bool tls_base_symbol_defined_
;
427 const Target::Target_info
Target_x86_64::x86_64_info
=
430 false, // is_big_endian
431 elfcpp::EM_X86_64
, // machine_code
432 false, // has_make_symbol
433 false, // has_resolve
434 true, // has_code_fill
435 true, // is_default_stack_executable
437 "/lib/ld64.so.1", // program interpreter
438 0x400000, // default_text_segment_address
439 0x1000, // abi_pagesize (overridable by -z max-page-size)
440 0x1000, // common_pagesize (overridable by -z common-page-size)
441 elfcpp::SHN_UNDEF
, // small_common_shndx
442 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
443 0, // small_common_section_flags
444 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
445 NULL
, // attributes_section
446 NULL
// attributes_vendor
449 // This is called when a new output section is created. This is where
450 // we handle the SHF_X86_64_LARGE.
453 Target_x86_64::do_new_output_section(Output_section
*os
) const
455 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
456 os
->set_is_large_section();
459 // Get the GOT section, creating it if necessary.
461 Output_data_got
<64, false>*
462 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
464 if (this->got_
== NULL
)
466 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
468 this->got_
= new Output_data_got
<64, false>();
471 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
473 | elfcpp::SHF_WRITE
),
474 this->got_
, false, true, true,
477 this->got_plt_
= new Output_data_space(8, "** GOT PLT");
478 os
= layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
480 | elfcpp::SHF_WRITE
),
481 this->got_plt_
, false, false,
484 // The first three entries are reserved.
485 this->got_plt_
->set_current_data_size(3 * 8);
487 // Those bytes can go into the relro segment.
488 layout
->increase_relro(3 * 8);
490 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
491 this->global_offset_table_
=
492 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
493 Symbol_table::PREDEFINED
,
495 0, 0, elfcpp::STT_OBJECT
,
497 elfcpp::STV_HIDDEN
, 0,
504 // Get the dynamic reloc section, creating it if necessary.
506 Target_x86_64::Reloc_section
*
507 Target_x86_64::rela_dyn_section(Layout
* layout
)
509 if (this->rela_dyn_
== NULL
)
511 gold_assert(layout
!= NULL
);
512 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
513 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
514 elfcpp::SHF_ALLOC
, this->rela_dyn_
, true,
515 false, false, false);
517 return this->rela_dyn_
;
520 // A class to handle the PLT data.
522 class Output_data_plt_x86_64
: public Output_section_data
525 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
527 Output_data_plt_x86_64(Layout
*, Output_data_got
<64, false>*,
530 // Add an entry to the PLT.
532 add_entry(Symbol
* gsym
);
534 // Add the reserved TLSDESC_PLT entry to the PLT.
536 reserve_tlsdesc_entry(unsigned int got_offset
)
537 { this->tlsdesc_got_offset_
= got_offset
; }
539 // Return true if a TLSDESC_PLT entry has been reserved.
541 has_tlsdesc_entry() const
542 { return this->tlsdesc_got_offset_
!= -1U; }
544 // Return the GOT offset for the reserved TLSDESC_PLT entry.
546 get_tlsdesc_got_offset() const
547 { return this->tlsdesc_got_offset_
; }
549 // Return the offset of the reserved TLSDESC_PLT entry.
551 get_tlsdesc_plt_offset() const
552 { return (this->count_
+ 1) * plt_entry_size
; }
554 // Return the .rel.plt section data.
557 { return this->rel_
; }
561 do_adjust_output_section(Output_section
* os
);
563 // Write to a map file.
565 do_print_to_mapfile(Mapfile
* mapfile
) const
566 { mapfile
->print_output_data(this, _("** PLT")); }
569 // The size of an entry in the PLT.
570 static const int plt_entry_size
= 16;
572 // The first entry in the PLT.
573 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
574 // procedure linkage table for both programs and shared objects."
575 static unsigned char first_plt_entry
[plt_entry_size
];
577 // Other entries in the PLT for an executable.
578 static unsigned char plt_entry
[plt_entry_size
];
580 // The reserved TLSDESC entry in the PLT for an executable.
581 static unsigned char tlsdesc_plt_entry
[plt_entry_size
];
583 // Set the final size.
585 set_final_data_size();
587 // Write out the PLT data.
589 do_write(Output_file
*);
591 // The reloc section.
594 Output_data_got
<64, false>* got_
;
595 // The .got.plt section.
596 Output_data_space
* got_plt_
;
597 // The number of PLT entries.
599 // Offset of the reserved TLSDESC_GOT entry when needed.
600 unsigned int tlsdesc_got_offset_
;
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_x86_64::Output_data_plt_x86_64(Layout
* layout
,
608 Output_data_got
<64, false>* got
,
609 Output_data_space
* got_plt
)
610 : Output_section_data(8), got_(got
), got_plt_(got_plt
), count_(0),
611 tlsdesc_got_offset_(-1U)
613 this->rel_
= new Reloc_section(false);
614 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
615 elfcpp::SHF_ALLOC
, this->rel_
, true,
616 false, false, false);
620 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
622 os
->set_entsize(plt_entry_size
);
625 // Add an entry to the PLT.
628 Output_data_plt_x86_64::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
+ 8);
645 // Every PLT entry needs a reloc.
646 gsym
->set_needs_dynsym_entry();
647 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_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 // Set the final size.
657 Output_data_plt_x86_64::set_final_data_size()
659 unsigned int count
= this->count_
;
660 if (this->has_tlsdesc_entry())
662 this->set_data_size((count
+ 1) * plt_entry_size
);
665 // The first entry in the PLT for an executable.
667 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
669 // From AMD64 ABI Draft 0.98, page 76
670 0xff, 0x35, // pushq contents of memory address
671 0, 0, 0, 0, // replaced with address of .got + 8
672 0xff, 0x25, // jmp indirect
673 0, 0, 0, 0, // replaced with address of .got + 16
674 0x90, 0x90, 0x90, 0x90 // noop (x4)
677 // Subsequent entries in the PLT for an executable.
679 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
681 // From AMD64 ABI Draft 0.98, page 76
682 0xff, 0x25, // jmpq indirect
683 0, 0, 0, 0, // replaced with address of symbol in .got
684 0x68, // pushq immediate
685 0, 0, 0, 0, // replaced with offset into relocation table
686 0xe9, // jmpq relative
687 0, 0, 0, 0 // replaced with offset to start of .plt
690 // The reserved TLSDESC entry in the PLT for an executable.
692 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry
[plt_entry_size
] =
694 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
695 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
696 0xff, 0x35, // pushq x(%rip)
697 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
698 0xff, 0x25, // jmpq *y(%rip)
699 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
704 // Write out the PLT. This uses the hand-coded instructions above,
705 // and adjusts them as needed. This is specified by the AMD64 ABI.
708 Output_data_plt_x86_64::do_write(Output_file
* of
)
710 const off_t offset
= this->offset();
711 const section_size_type oview_size
=
712 convert_to_section_size_type(this->data_size());
713 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
715 const off_t got_file_offset
= this->got_plt_
->offset();
716 const section_size_type got_size
=
717 convert_to_section_size_type(this->got_plt_
->data_size());
718 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
721 unsigned char* pov
= oview
;
723 // The base address of the .plt section.
724 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
725 // The base address of the .got section.
726 elfcpp::Elf_types
<64>::Elf_Addr got_base
= this->got_
->address();
727 // The base address of the PLT portion of the .got section,
728 // which is where the GOT pointer will point, and where the
729 // three reserved GOT entries are located.
730 elfcpp::Elf_types
<64>::Elf_Addr got_address
= this->got_plt_
->address();
732 memcpy(pov
, first_plt_entry
, plt_entry_size
);
733 // We do a jmp relative to the PC at the end of this instruction.
734 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
736 - (plt_address
+ 6)));
737 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
739 - (plt_address
+ 12)));
740 pov
+= plt_entry_size
;
742 unsigned char* got_pov
= got_view
;
744 memset(got_pov
, 0, 24);
747 unsigned int plt_offset
= plt_entry_size
;
748 unsigned int got_offset
= 24;
749 const unsigned int count
= this->count_
;
750 for (unsigned int plt_index
= 0;
753 pov
+= plt_entry_size
,
755 plt_offset
+= plt_entry_size
,
758 // Set and adjust the PLT entry itself.
759 memcpy(pov
, plt_entry
, plt_entry_size
);
760 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
761 (got_address
+ got_offset
762 - (plt_address
+ plt_offset
765 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
766 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
767 - (plt_offset
+ plt_entry_size
));
769 // Set the entry in the GOT.
770 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
773 if (this->has_tlsdesc_entry())
775 // Set and adjust the reserved TLSDESC PLT entry.
776 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
777 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
778 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
780 - (plt_address
+ plt_offset
782 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
785 - (plt_address
+ plt_offset
787 pov
+= plt_entry_size
;
790 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
791 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
793 of
->write_output_view(offset
, oview_size
, oview
);
794 of
->write_output_view(got_file_offset
, got_size
, got_view
);
797 // Create the PLT section.
800 Target_x86_64::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
802 if (this->plt_
== NULL
)
804 // Create the GOT sections first.
805 this->got_section(symtab
, layout
);
807 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_
,
809 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
811 | elfcpp::SHF_EXECINSTR
),
812 this->plt_
, false, false, false, false);
816 // Create a PLT entry for a global symbol.
819 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
822 if (gsym
->has_plt_offset())
825 if (this->plt_
== NULL
)
826 this->make_plt_section(symtab
, layout
);
828 this->plt_
->add_entry(gsym
);
831 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
834 Target_x86_64::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 the reserved PLT and GOT entries for the TLS descriptor resolver.
860 Target_x86_64::reserve_tlsdesc_entries(Symbol_table
* symtab
,
863 if (this->plt_
== NULL
)
864 this->make_plt_section(symtab
, layout
);
866 if (!this->plt_
->has_tlsdesc_entry())
868 // Allocate the TLSDESC_GOT entry.
869 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
870 unsigned int got_offset
= got
->add_constant(0);
872 // Allocate the TLSDESC_PLT entry.
873 this->plt_
->reserve_tlsdesc_entry(got_offset
);
877 // Create a GOT entry for the TLS module index.
880 Target_x86_64::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
881 Sized_relobj
<64, false>* object
)
883 if (this->got_mod_index_offset_
== -1U)
885 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
886 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
887 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
888 unsigned int got_offset
= got
->add_constant(0);
889 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
891 got
->add_constant(0);
892 this->got_mod_index_offset_
= got_offset
;
894 return this->got_mod_index_offset_
;
897 // Optimize the TLS relocation type based on what we know about the
898 // symbol. IS_FINAL is true if the final address of this symbol is
899 // known at link time.
901 tls::Tls_optimization
902 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
904 // If we are generating a shared library, then we can't do anything
906 if (parameters
->options().shared())
907 return tls::TLSOPT_NONE
;
911 case elfcpp::R_X86_64_TLSGD
:
912 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
913 case elfcpp::R_X86_64_TLSDESC_CALL
:
914 // These are General-Dynamic which permits fully general TLS
915 // access. Since we know that we are generating an executable,
916 // we can convert this to Initial-Exec. If we also know that
917 // this is a local symbol, we can further switch to Local-Exec.
919 return tls::TLSOPT_TO_LE
;
920 return tls::TLSOPT_TO_IE
;
922 case elfcpp::R_X86_64_TLSLD
:
923 // This is Local-Dynamic, which refers to a local symbol in the
924 // dynamic TLS block. Since we know that we generating an
925 // executable, we can switch to Local-Exec.
926 return tls::TLSOPT_TO_LE
;
928 case elfcpp::R_X86_64_DTPOFF32
:
929 case elfcpp::R_X86_64_DTPOFF64
:
930 // Another Local-Dynamic reloc.
931 return tls::TLSOPT_TO_LE
;
933 case elfcpp::R_X86_64_GOTTPOFF
:
934 // These are Initial-Exec relocs which get the thread offset
935 // from the GOT. If we know that we are linking against the
936 // local symbol, we can switch to Local-Exec, which links the
937 // thread offset into the instruction.
939 return tls::TLSOPT_TO_LE
;
940 return tls::TLSOPT_NONE
;
942 case elfcpp::R_X86_64_TPOFF32
:
943 // When we already have Local-Exec, there is nothing further we
945 return tls::TLSOPT_NONE
;
952 // Report an unsupported relocation against a local symbol.
955 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
958 gold_error(_("%s: unsupported reloc %u against local symbol"),
959 object
->name().c_str(), r_type
);
962 // We are about to emit a dynamic relocation of type R_TYPE. If the
963 // dynamic linker does not support it, issue an error. The GNU linker
964 // only issues a non-PIC error for an allocated read-only section.
965 // Here we know the section is allocated, but we don't know that it is
966 // read-only. But we check for all the relocation types which the
967 // glibc dynamic linker supports, so it seems appropriate to issue an
968 // error even if the section is not read-only.
971 Target_x86_64::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
)
975 // These are the relocation types supported by glibc for x86_64.
976 case elfcpp::R_X86_64_RELATIVE
:
977 case elfcpp::R_X86_64_GLOB_DAT
:
978 case elfcpp::R_X86_64_JUMP_SLOT
:
979 case elfcpp::R_X86_64_DTPMOD64
:
980 case elfcpp::R_X86_64_DTPOFF64
:
981 case elfcpp::R_X86_64_TPOFF64
:
982 case elfcpp::R_X86_64_64
:
983 case elfcpp::R_X86_64_32
:
984 case elfcpp::R_X86_64_PC32
:
985 case elfcpp::R_X86_64_COPY
:
989 // This prevents us from issuing more than one error per reloc
990 // section. But we can still wind up issuing more than one
991 // error per object file.
992 if (this->issued_non_pic_error_
)
994 gold_assert(parameters
->options().output_is_position_independent());
995 object
->error(_("requires unsupported dynamic reloc; "
996 "recompile with -fPIC"));
997 this->issued_non_pic_error_
= true;
1000 case elfcpp::R_X86_64_NONE
:
1005 // Scan a relocation for a local symbol.
1008 Target_x86_64::Scan::local(Symbol_table
* symtab
,
1010 Target_x86_64
* target
,
1011 Sized_relobj
<64, false>* object
,
1012 unsigned int data_shndx
,
1013 Output_section
* output_section
,
1014 const elfcpp::Rela
<64, false>& reloc
,
1015 unsigned int r_type
,
1016 const elfcpp::Sym
<64, false>& lsym
)
1020 case elfcpp::R_X86_64_NONE
:
1021 case elfcpp::R_386_GNU_VTINHERIT
:
1022 case elfcpp::R_386_GNU_VTENTRY
:
1025 case elfcpp::R_X86_64_64
:
1026 // If building a shared library (or a position-independent
1027 // executable), we need to create a dynamic relocation for this
1028 // location. The relocation applied at link time will apply the
1029 // link-time value, so we flag the location with an
1030 // R_X86_64_RELATIVE relocation so the dynamic loader can
1031 // relocate it easily.
1032 if (parameters
->options().output_is_position_independent())
1034 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1035 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1036 rela_dyn
->add_local_relative(object
, r_sym
,
1037 elfcpp::R_X86_64_RELATIVE
,
1038 output_section
, data_shndx
,
1039 reloc
.get_r_offset(),
1040 reloc
.get_r_addend());
1044 case elfcpp::R_X86_64_32
:
1045 case elfcpp::R_X86_64_32S
:
1046 case elfcpp::R_X86_64_16
:
1047 case elfcpp::R_X86_64_8
:
1048 // If building a shared library (or a position-independent
1049 // executable), we need to create a dynamic relocation for this
1050 // location. We can't use an R_X86_64_RELATIVE relocation
1051 // because that is always a 64-bit relocation.
1052 if (parameters
->options().output_is_position_independent())
1054 this->check_non_pic(object
, r_type
);
1056 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1057 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1058 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1059 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1060 data_shndx
, reloc
.get_r_offset(),
1061 reloc
.get_r_addend());
1064 gold_assert(lsym
.get_st_value() == 0);
1065 unsigned int shndx
= lsym
.get_st_shndx();
1067 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1070 object
->error(_("section symbol %u has bad shndx %u"),
1073 rela_dyn
->add_local_section(object
, shndx
,
1074 r_type
, output_section
,
1075 data_shndx
, reloc
.get_r_offset(),
1076 reloc
.get_r_addend());
1081 case elfcpp::R_X86_64_PC64
:
1082 case elfcpp::R_X86_64_PC32
:
1083 case elfcpp::R_X86_64_PC16
:
1084 case elfcpp::R_X86_64_PC8
:
1087 case elfcpp::R_X86_64_PLT32
:
1088 // Since we know this is a local symbol, we can handle this as a
1092 case elfcpp::R_X86_64_GOTPC32
:
1093 case elfcpp::R_X86_64_GOTOFF64
:
1094 case elfcpp::R_X86_64_GOTPC64
:
1095 case elfcpp::R_X86_64_PLTOFF64
:
1096 // We need a GOT section.
1097 target
->got_section(symtab
, layout
);
1098 // For PLTOFF64, we'd normally want a PLT section, but since we
1099 // know this is a local symbol, no PLT is needed.
1102 case elfcpp::R_X86_64_GOT64
:
1103 case elfcpp::R_X86_64_GOT32
:
1104 case elfcpp::R_X86_64_GOTPCREL64
:
1105 case elfcpp::R_X86_64_GOTPCREL
:
1106 case elfcpp::R_X86_64_GOTPLT64
:
1108 // The symbol requires a GOT entry.
1109 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1110 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1111 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
1113 // If we are generating a shared object, we need to add a
1114 // dynamic relocation for this symbol's GOT entry.
1115 if (parameters
->options().output_is_position_independent())
1117 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1118 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1119 if (r_type
!= elfcpp::R_X86_64_GOT32
)
1120 rela_dyn
->add_local_relative(
1121 object
, r_sym
, elfcpp::R_X86_64_RELATIVE
, got
,
1122 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
1125 this->check_non_pic(object
, r_type
);
1127 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1128 rela_dyn
->add_local(
1129 object
, r_sym
, r_type
, got
,
1130 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
1134 // For GOTPLT64, we'd normally want a PLT section, but since
1135 // we know this is a local symbol, no PLT is needed.
1139 case elfcpp::R_X86_64_COPY
:
1140 case elfcpp::R_X86_64_GLOB_DAT
:
1141 case elfcpp::R_X86_64_JUMP_SLOT
:
1142 case elfcpp::R_X86_64_RELATIVE
:
1143 // These are outstanding tls relocs, which are unexpected when linking
1144 case elfcpp::R_X86_64_TPOFF64
:
1145 case elfcpp::R_X86_64_DTPMOD64
:
1146 case elfcpp::R_X86_64_TLSDESC
:
1147 gold_error(_("%s: unexpected reloc %u in object file"),
1148 object
->name().c_str(), r_type
);
1151 // These are initial tls relocs, which are expected when linking
1152 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1153 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1154 case elfcpp::R_X86_64_TLSDESC_CALL
:
1155 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1156 case elfcpp::R_X86_64_DTPOFF32
:
1157 case elfcpp::R_X86_64_DTPOFF64
:
1158 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1159 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1161 bool output_is_shared
= parameters
->options().shared();
1162 const tls::Tls_optimization optimized_type
1163 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
1166 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1167 if (optimized_type
== tls::TLSOPT_NONE
)
1169 // Create a pair of GOT entries for the module index and
1170 // dtv-relative offset.
1171 Output_data_got
<64, false>* got
1172 = target
->got_section(symtab
, layout
);
1173 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1174 unsigned int shndx
= lsym
.get_st_shndx();
1176 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1178 object
->error(_("local symbol %u has bad shndx %u"),
1181 got
->add_local_pair_with_rela(object
, r_sym
,
1184 target
->rela_dyn_section(layout
),
1185 elfcpp::R_X86_64_DTPMOD64
, 0);
1187 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1188 unsupported_reloc_local(object
, r_type
);
1191 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1192 target
->define_tls_base_symbol(symtab
, layout
);
1193 if (optimized_type
== tls::TLSOPT_NONE
)
1195 // Create reserved PLT and GOT entries for the resolver.
1196 target
->reserve_tlsdesc_entries(symtab
, layout
);
1198 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1199 Output_data_got
<64, false>* got
1200 = target
->got_section(symtab
, layout
);
1201 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1202 unsigned int shndx
= lsym
.get_st_shndx();
1204 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1206 object
->error(_("local symbol %u has bad shndx %u"),
1209 got
->add_local_pair_with_rela(object
, r_sym
,
1212 target
->rela_dyn_section(layout
),
1213 elfcpp::R_X86_64_TLSDESC
, 0);
1215 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1216 unsupported_reloc_local(object
, r_type
);
1219 case elfcpp::R_X86_64_TLSDESC_CALL
:
1222 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1223 if (optimized_type
== tls::TLSOPT_NONE
)
1225 // Create a GOT entry for the module index.
1226 target
->got_mod_index_entry(symtab
, layout
, object
);
1228 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1229 unsupported_reloc_local(object
, r_type
);
1232 case elfcpp::R_X86_64_DTPOFF32
:
1233 case elfcpp::R_X86_64_DTPOFF64
:
1236 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1237 layout
->set_has_static_tls();
1238 if (optimized_type
== tls::TLSOPT_NONE
)
1240 // Create a GOT entry for the tp-relative offset.
1241 Output_data_got
<64, false>* got
1242 = target
->got_section(symtab
, layout
);
1243 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1244 got
->add_local_with_rela(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
1245 target
->rela_dyn_section(layout
),
1246 elfcpp::R_X86_64_TPOFF64
);
1248 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1249 unsupported_reloc_local(object
, r_type
);
1252 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1253 layout
->set_has_static_tls();
1254 if (output_is_shared
)
1255 unsupported_reloc_local(object
, r_type
);
1264 case elfcpp::R_X86_64_SIZE32
:
1265 case elfcpp::R_X86_64_SIZE64
:
1267 gold_error(_("%s: unsupported reloc %u against local symbol"),
1268 object
->name().c_str(), r_type
);
1274 // Report an unsupported relocation against a global symbol.
1277 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
1278 unsigned int r_type
,
1281 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1282 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1285 // Scan a relocation for a global symbol.
1288 Target_x86_64::Scan::global(Symbol_table
* symtab
,
1290 Target_x86_64
* target
,
1291 Sized_relobj
<64, false>* object
,
1292 unsigned int data_shndx
,
1293 Output_section
* output_section
,
1294 const elfcpp::Rela
<64, false>& reloc
,
1295 unsigned int r_type
,
1300 case elfcpp::R_X86_64_NONE
:
1301 case elfcpp::R_386_GNU_VTINHERIT
:
1302 case elfcpp::R_386_GNU_VTENTRY
:
1305 case elfcpp::R_X86_64_64
:
1306 case elfcpp::R_X86_64_32
:
1307 case elfcpp::R_X86_64_32S
:
1308 case elfcpp::R_X86_64_16
:
1309 case elfcpp::R_X86_64_8
:
1311 // Make a PLT entry if necessary.
1312 if (gsym
->needs_plt_entry())
1314 target
->make_plt_entry(symtab
, layout
, gsym
);
1315 // Since this is not a PC-relative relocation, we may be
1316 // taking the address of a function. In that case we need to
1317 // set the entry in the dynamic symbol table to the address of
1319 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1320 gsym
->set_needs_dynsym_value();
1322 // Make a dynamic relocation if necessary.
1323 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1325 if (gsym
->may_need_copy_reloc())
1327 target
->copy_reloc(symtab
, layout
, object
,
1328 data_shndx
, output_section
, gsym
, reloc
);
1330 else if (r_type
== elfcpp::R_X86_64_64
1331 && gsym
->can_use_relative_reloc(false))
1333 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1334 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1335 output_section
, object
,
1336 data_shndx
, reloc
.get_r_offset(),
1337 reloc
.get_r_addend());
1341 this->check_non_pic(object
, r_type
);
1342 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1343 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1344 data_shndx
, reloc
.get_r_offset(),
1345 reloc
.get_r_addend());
1351 case elfcpp::R_X86_64_PC64
:
1352 case elfcpp::R_X86_64_PC32
:
1353 case elfcpp::R_X86_64_PC16
:
1354 case elfcpp::R_X86_64_PC8
:
1356 // Make a PLT entry if necessary.
1357 if (gsym
->needs_plt_entry())
1358 target
->make_plt_entry(symtab
, layout
, gsym
);
1359 // Make a dynamic relocation if necessary.
1360 int flags
= Symbol::NON_PIC_REF
;
1361 if (gsym
->is_func())
1362 flags
|= Symbol::FUNCTION_CALL
;
1363 if (gsym
->needs_dynamic_reloc(flags
))
1365 if (gsym
->may_need_copy_reloc())
1367 target
->copy_reloc(symtab
, layout
, object
,
1368 data_shndx
, output_section
, gsym
, reloc
);
1372 this->check_non_pic(object
, r_type
);
1373 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1374 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1375 data_shndx
, reloc
.get_r_offset(),
1376 reloc
.get_r_addend());
1382 case elfcpp::R_X86_64_GOT64
:
1383 case elfcpp::R_X86_64_GOT32
:
1384 case elfcpp::R_X86_64_GOTPCREL64
:
1385 case elfcpp::R_X86_64_GOTPCREL
:
1386 case elfcpp::R_X86_64_GOTPLT64
:
1388 // The symbol requires a GOT entry.
1389 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1390 if (gsym
->final_value_is_known())
1391 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1394 // If this symbol is not fully resolved, we need to add a
1395 // dynamic relocation for it.
1396 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1397 if (gsym
->is_from_dynobj()
1398 || gsym
->is_undefined()
1399 || gsym
->is_preemptible())
1400 got
->add_global_with_rela(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
1401 elfcpp::R_X86_64_GLOB_DAT
);
1404 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1405 rela_dyn
->add_global_relative(
1406 gsym
, elfcpp::R_X86_64_RELATIVE
, got
,
1407 gsym
->got_offset(GOT_TYPE_STANDARD
), 0);
1410 // For GOTPLT64, we also need a PLT entry (but only if the
1411 // symbol is not fully resolved).
1412 if (r_type
== elfcpp::R_X86_64_GOTPLT64
1413 && !gsym
->final_value_is_known())
1414 target
->make_plt_entry(symtab
, layout
, gsym
);
1418 case elfcpp::R_X86_64_PLT32
:
1419 // If the symbol is fully resolved, this is just a PC32 reloc.
1420 // Otherwise we need a PLT entry.
1421 if (gsym
->final_value_is_known())
1423 // If building a shared library, we can also skip the PLT entry
1424 // if the symbol is defined in the output file and is protected
1426 if (gsym
->is_defined()
1427 && !gsym
->is_from_dynobj()
1428 && !gsym
->is_preemptible())
1430 target
->make_plt_entry(symtab
, layout
, gsym
);
1433 case elfcpp::R_X86_64_GOTPC32
:
1434 case elfcpp::R_X86_64_GOTOFF64
:
1435 case elfcpp::R_X86_64_GOTPC64
:
1436 case elfcpp::R_X86_64_PLTOFF64
:
1437 // We need a GOT section.
1438 target
->got_section(symtab
, layout
);
1439 // For PLTOFF64, we also need a PLT entry (but only if the
1440 // symbol is not fully resolved).
1441 if (r_type
== elfcpp::R_X86_64_PLTOFF64
1442 && !gsym
->final_value_is_known())
1443 target
->make_plt_entry(symtab
, layout
, gsym
);
1446 case elfcpp::R_X86_64_COPY
:
1447 case elfcpp::R_X86_64_GLOB_DAT
:
1448 case elfcpp::R_X86_64_JUMP_SLOT
:
1449 case elfcpp::R_X86_64_RELATIVE
:
1450 // These are outstanding tls relocs, which are unexpected when linking
1451 case elfcpp::R_X86_64_TPOFF64
:
1452 case elfcpp::R_X86_64_DTPMOD64
:
1453 case elfcpp::R_X86_64_TLSDESC
:
1454 gold_error(_("%s: unexpected reloc %u in object file"),
1455 object
->name().c_str(), r_type
);
1458 // These are initial tls relocs, which are expected for global()
1459 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1460 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1461 case elfcpp::R_X86_64_TLSDESC_CALL
:
1462 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1463 case elfcpp::R_X86_64_DTPOFF32
:
1464 case elfcpp::R_X86_64_DTPOFF64
:
1465 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1466 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1468 const bool is_final
= gsym
->final_value_is_known();
1469 const tls::Tls_optimization optimized_type
1470 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1473 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1474 if (optimized_type
== tls::TLSOPT_NONE
)
1476 // Create a pair of GOT entries for the module index and
1477 // dtv-relative offset.
1478 Output_data_got
<64, false>* got
1479 = target
->got_section(symtab
, layout
);
1480 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_PAIR
,
1481 target
->rela_dyn_section(layout
),
1482 elfcpp::R_X86_64_DTPMOD64
,
1483 elfcpp::R_X86_64_DTPOFF64
);
1485 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1487 // Create a GOT entry for the tp-relative offset.
1488 Output_data_got
<64, false>* got
1489 = target
->got_section(symtab
, layout
);
1490 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1491 target
->rela_dyn_section(layout
),
1492 elfcpp::R_X86_64_TPOFF64
);
1494 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1495 unsupported_reloc_global(object
, r_type
, gsym
);
1498 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1499 target
->define_tls_base_symbol(symtab
, layout
);
1500 if (optimized_type
== tls::TLSOPT_NONE
)
1502 // Create reserved PLT and GOT entries for the resolver.
1503 target
->reserve_tlsdesc_entries(symtab
, layout
);
1505 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1506 Output_data_got
<64, false>* got
1507 = target
->got_section(symtab
, layout
);
1508 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_DESC
,
1509 target
->rela_dyn_section(layout
),
1510 elfcpp::R_X86_64_TLSDESC
, 0);
1512 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1514 // Create a GOT entry for the tp-relative offset.
1515 Output_data_got
<64, false>* got
1516 = target
->got_section(symtab
, layout
);
1517 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1518 target
->rela_dyn_section(layout
),
1519 elfcpp::R_X86_64_TPOFF64
);
1521 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1522 unsupported_reloc_global(object
, r_type
, gsym
);
1525 case elfcpp::R_X86_64_TLSDESC_CALL
:
1528 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1529 if (optimized_type
== tls::TLSOPT_NONE
)
1531 // Create a GOT entry for the module index.
1532 target
->got_mod_index_entry(symtab
, layout
, object
);
1534 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1535 unsupported_reloc_global(object
, r_type
, gsym
);
1538 case elfcpp::R_X86_64_DTPOFF32
:
1539 case elfcpp::R_X86_64_DTPOFF64
:
1542 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1543 layout
->set_has_static_tls();
1544 if (optimized_type
== tls::TLSOPT_NONE
)
1546 // Create a GOT entry for the tp-relative offset.
1547 Output_data_got
<64, false>* got
1548 = target
->got_section(symtab
, layout
);
1549 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1550 target
->rela_dyn_section(layout
),
1551 elfcpp::R_X86_64_TPOFF64
);
1553 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1554 unsupported_reloc_global(object
, r_type
, gsym
);
1557 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1558 layout
->set_has_static_tls();
1559 if (parameters
->options().shared())
1560 unsupported_reloc_local(object
, r_type
);
1569 case elfcpp::R_X86_64_SIZE32
:
1570 case elfcpp::R_X86_64_SIZE64
:
1572 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1573 object
->name().c_str(), r_type
,
1574 gsym
->demangled_name().c_str());
1580 Target_x86_64::gc_process_relocs(Symbol_table
* symtab
,
1582 Sized_relobj
<64, false>* object
,
1583 unsigned int data_shndx
,
1584 unsigned int sh_type
,
1585 const unsigned char* prelocs
,
1587 Output_section
* output_section
,
1588 bool needs_special_offset_handling
,
1589 size_t local_symbol_count
,
1590 const unsigned char* plocal_symbols
)
1593 if (sh_type
== elfcpp::SHT_REL
)
1598 gold::gc_process_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1599 Target_x86_64::Scan
>(
1608 needs_special_offset_handling
,
1613 // Scan relocations for a section.
1616 Target_x86_64::scan_relocs(Symbol_table
* symtab
,
1618 Sized_relobj
<64, false>* object
,
1619 unsigned int data_shndx
,
1620 unsigned int sh_type
,
1621 const unsigned char* prelocs
,
1623 Output_section
* output_section
,
1624 bool needs_special_offset_handling
,
1625 size_t local_symbol_count
,
1626 const unsigned char* plocal_symbols
)
1628 if (sh_type
== elfcpp::SHT_REL
)
1630 gold_error(_("%s: unsupported REL reloc section"),
1631 object
->name().c_str());
1635 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1636 Target_x86_64::Scan
>(
1645 needs_special_offset_handling
,
1650 // Finalize the sections.
1653 Target_x86_64::do_finalize_sections(
1655 const Input_objects
*,
1656 Symbol_table
* symtab
)
1658 // Fill in some more dynamic tags.
1659 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1662 if (this->got_plt_
!= NULL
1663 && this->got_plt_
->output_section() != NULL
)
1664 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1666 if (this->plt_
!= NULL
1667 && this->plt_
->output_section() != NULL
)
1669 const Output_data
* od
= this->plt_
->rel_plt();
1670 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1671 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1672 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_RELA
);
1673 if (this->plt_
->has_tlsdesc_entry())
1675 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
1676 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
1677 this->got_
->finalize_data_size();
1678 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
1679 this->plt_
, plt_offset
);
1680 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
1681 this->got_
, got_offset
);
1685 if (this->rela_dyn_
!= NULL
1686 && this->rela_dyn_
->output_section() != NULL
)
1688 const Output_data
* od
= this->rela_dyn_
;
1689 odyn
->add_section_address(elfcpp::DT_RELA
, od
);
1690 odyn
->add_section_size(elfcpp::DT_RELASZ
, od
);
1691 odyn
->add_constant(elfcpp::DT_RELAENT
,
1692 elfcpp::Elf_sizes
<64>::rela_size
);
1695 if (!parameters
->options().shared())
1697 // The value of the DT_DEBUG tag is filled in by the dynamic
1698 // linker at run time, and used by the debugger.
1699 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1703 // Emit any relocs we saved in an attempt to avoid generating COPY
1705 if (this->copy_relocs_
.any_saved_relocs())
1706 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
1708 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1709 // the .got.plt section.
1710 Symbol
* sym
= this->global_offset_table_
;
1713 uint64_t data_size
= this->got_plt_
->current_data_size();
1714 symtab
->get_sized_symbol
<64>(sym
)->set_symsize(data_size
);
1718 // Perform a relocation.
1721 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1722 Target_x86_64
* target
,
1725 const elfcpp::Rela
<64, false>& rela
,
1726 unsigned int r_type
,
1727 const Sized_symbol
<64>* gsym
,
1728 const Symbol_value
<64>* psymval
,
1729 unsigned char* view
,
1730 elfcpp::Elf_types
<64>::Elf_Addr address
,
1731 section_size_type view_size
)
1733 if (this->skip_call_tls_get_addr_
)
1735 if ((r_type
!= elfcpp::R_X86_64_PLT32
1736 && r_type
!= elfcpp::R_X86_64_PC32
)
1738 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1740 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1741 _("missing expected TLS relocation"));
1745 this->skip_call_tls_get_addr_
= false;
1750 // Pick the value to use for symbols defined in shared objects.
1751 Symbol_value
<64> symval
;
1753 && gsym
->use_plt_offset(r_type
== elfcpp::R_X86_64_PC64
1754 || r_type
== elfcpp::R_X86_64_PC32
1755 || r_type
== elfcpp::R_X86_64_PC16
1756 || r_type
== elfcpp::R_X86_64_PC8
))
1758 symval
.set_output_value(target
->plt_section()->address()
1759 + gsym
->plt_offset());
1763 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1764 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1766 // Get the GOT offset if needed.
1767 // The GOT pointer points to the end of the GOT section.
1768 // We need to subtract the size of the GOT section to get
1769 // the actual offset to use in the relocation.
1770 bool have_got_offset
= false;
1771 unsigned int got_offset
= 0;
1774 case elfcpp::R_X86_64_GOT32
:
1775 case elfcpp::R_X86_64_GOT64
:
1776 case elfcpp::R_X86_64_GOTPLT64
:
1777 case elfcpp::R_X86_64_GOTPCREL
:
1778 case elfcpp::R_X86_64_GOTPCREL64
:
1781 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1782 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
1786 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1787 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1788 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1789 - target
->got_size());
1791 have_got_offset
= true;
1800 case elfcpp::R_X86_64_NONE
:
1801 case elfcpp::R_386_GNU_VTINHERIT
:
1802 case elfcpp::R_386_GNU_VTENTRY
:
1805 case elfcpp::R_X86_64_64
:
1806 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1809 case elfcpp::R_X86_64_PC64
:
1810 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1814 case elfcpp::R_X86_64_32
:
1815 // FIXME: we need to verify that value + addend fits into 32 bits:
1816 // uint64_t x = value + addend;
1817 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1818 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1819 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1822 case elfcpp::R_X86_64_32S
:
1823 // FIXME: we need to verify that value + addend fits into 32 bits:
1824 // int64_t x = value + addend; // note this quantity is signed!
1825 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1826 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1829 case elfcpp::R_X86_64_PC32
:
1830 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1834 case elfcpp::R_X86_64_16
:
1835 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
1838 case elfcpp::R_X86_64_PC16
:
1839 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
1843 case elfcpp::R_X86_64_8
:
1844 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
1847 case elfcpp::R_X86_64_PC8
:
1848 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
1852 case elfcpp::R_X86_64_PLT32
:
1853 gold_assert(gsym
== NULL
1854 || gsym
->has_plt_offset()
1855 || gsym
->final_value_is_known()
1856 || (gsym
->is_defined()
1857 && !gsym
->is_from_dynobj()
1858 && !gsym
->is_preemptible()));
1859 // Note: while this code looks the same as for R_X86_64_PC32, it
1860 // behaves differently because psymval was set to point to
1861 // the PLT entry, rather than the symbol, in Scan::global().
1862 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1866 case elfcpp::R_X86_64_PLTOFF64
:
1869 gold_assert(gsym
->has_plt_offset()
1870 || gsym
->final_value_is_known());
1871 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
1872 got_address
= target
->got_section(NULL
, NULL
)->address();
1873 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
1874 addend
- got_address
);
1877 case elfcpp::R_X86_64_GOT32
:
1878 gold_assert(have_got_offset
);
1879 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
1882 case elfcpp::R_X86_64_GOTPC32
:
1885 elfcpp::Elf_types
<64>::Elf_Addr value
;
1886 value
= target
->got_plt_section()->address();
1887 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1891 case elfcpp::R_X86_64_GOT64
:
1892 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1893 // Since we always add a PLT entry, this is equivalent.
1894 case elfcpp::R_X86_64_GOTPLT64
:
1895 gold_assert(have_got_offset
);
1896 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
1899 case elfcpp::R_X86_64_GOTPC64
:
1902 elfcpp::Elf_types
<64>::Elf_Addr value
;
1903 value
= target
->got_plt_section()->address();
1904 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1908 case elfcpp::R_X86_64_GOTOFF64
:
1910 elfcpp::Elf_types
<64>::Elf_Addr value
;
1911 value
= (psymval
->value(object
, 0)
1912 - target
->got_plt_section()->address());
1913 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
1917 case elfcpp::R_X86_64_GOTPCREL
:
1919 gold_assert(have_got_offset
);
1920 elfcpp::Elf_types
<64>::Elf_Addr value
;
1921 value
= target
->got_plt_section()->address() + got_offset
;
1922 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1926 case elfcpp::R_X86_64_GOTPCREL64
:
1928 gold_assert(have_got_offset
);
1929 elfcpp::Elf_types
<64>::Elf_Addr value
;
1930 value
= target
->got_plt_section()->address() + got_offset
;
1931 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1935 case elfcpp::R_X86_64_COPY
:
1936 case elfcpp::R_X86_64_GLOB_DAT
:
1937 case elfcpp::R_X86_64_JUMP_SLOT
:
1938 case elfcpp::R_X86_64_RELATIVE
:
1939 // These are outstanding tls relocs, which are unexpected when linking
1940 case elfcpp::R_X86_64_TPOFF64
:
1941 case elfcpp::R_X86_64_DTPMOD64
:
1942 case elfcpp::R_X86_64_TLSDESC
:
1943 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1944 _("unexpected reloc %u in object file"),
1948 // These are initial tls relocs, which are expected when linking
1949 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1950 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1951 case elfcpp::R_X86_64_TLSDESC_CALL
:
1952 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1953 case elfcpp::R_X86_64_DTPOFF32
:
1954 case elfcpp::R_X86_64_DTPOFF64
:
1955 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1956 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1957 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
1958 view
, address
, view_size
);
1961 case elfcpp::R_X86_64_SIZE32
:
1962 case elfcpp::R_X86_64_SIZE64
:
1964 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1965 _("unsupported reloc %u"),
1973 // Perform a TLS relocation.
1976 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
1977 Target_x86_64
* target
,
1979 const elfcpp::Rela
<64, false>& rela
,
1980 unsigned int r_type
,
1981 const Sized_symbol
<64>* gsym
,
1982 const Symbol_value
<64>* psymval
,
1983 unsigned char* view
,
1984 elfcpp::Elf_types
<64>::Elf_Addr address
,
1985 section_size_type view_size
)
1987 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1989 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1990 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1992 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1994 const bool is_final
= (gsym
== NULL
1995 ? !parameters
->options().output_is_position_independent()
1996 : gsym
->final_value_is_known());
1997 const tls::Tls_optimization optimized_type
1998 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
2001 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2002 this->saw_tls_block_reloc_
= true;
2003 if (optimized_type
== tls::TLSOPT_TO_LE
)
2005 gold_assert(tls_segment
!= NULL
);
2006 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2007 rela
, r_type
, value
, view
,
2013 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2014 ? GOT_TYPE_TLS_OFFSET
2015 : GOT_TYPE_TLS_PAIR
);
2016 unsigned int got_offset
;
2019 gold_assert(gsym
->has_got_offset(got_type
));
2020 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2024 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2025 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2026 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2027 - target
->got_size());
2029 if (optimized_type
== tls::TLSOPT_TO_IE
)
2031 gold_assert(tls_segment
!= NULL
);
2032 value
= target
->got_plt_section()->address() + got_offset
;
2033 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2034 value
, view
, address
, view_size
);
2037 else if (optimized_type
== tls::TLSOPT_NONE
)
2039 // Relocate the field with the offset of the pair of GOT
2041 value
= target
->got_plt_section()->address() + got_offset
;
2042 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2047 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2048 _("unsupported reloc %u"), r_type
);
2051 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2052 case elfcpp::R_X86_64_TLSDESC_CALL
:
2053 this->saw_tls_block_reloc_
= true;
2054 if (optimized_type
== tls::TLSOPT_TO_LE
)
2056 gold_assert(tls_segment
!= NULL
);
2057 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2058 rela
, r_type
, value
, view
,
2064 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2065 ? GOT_TYPE_TLS_OFFSET
2066 : GOT_TYPE_TLS_DESC
);
2067 unsigned int got_offset
;
2070 gold_assert(gsym
->has_got_offset(got_type
));
2071 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2075 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2076 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2077 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2078 - target
->got_size());
2080 if (optimized_type
== tls::TLSOPT_TO_IE
)
2082 gold_assert(tls_segment
!= NULL
);
2083 value
= target
->got_plt_section()->address() + got_offset
;
2084 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
,
2085 rela
, r_type
, value
, view
, address
,
2089 else if (optimized_type
== tls::TLSOPT_NONE
)
2091 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2093 // Relocate the field with the offset of the pair of GOT
2095 value
= target
->got_plt_section()->address() + got_offset
;
2096 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2102 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2103 _("unsupported reloc %u"), r_type
);
2106 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2107 this->saw_tls_block_reloc_
= true;
2108 if (optimized_type
== tls::TLSOPT_TO_LE
)
2110 gold_assert(tls_segment
!= NULL
);
2111 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2112 value
, view
, view_size
);
2115 else if (optimized_type
== tls::TLSOPT_NONE
)
2117 // Relocate the field with the offset of the GOT entry for
2118 // the module index.
2119 unsigned int got_offset
;
2120 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2121 - target
->got_size());
2122 value
= target
->got_plt_section()->address() + got_offset
;
2123 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2127 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2128 _("unsupported reloc %u"), r_type
);
2131 case elfcpp::R_X86_64_DTPOFF32
:
2132 if (optimized_type
== tls::TLSOPT_TO_LE
)
2134 // This relocation type is used in debugging information.
2135 // In that case we need to not optimize the value. If we
2136 // haven't seen a TLSLD reloc, then we assume we should not
2137 // optimize this reloc.
2138 if (this->saw_tls_block_reloc_
)
2140 gold_assert(tls_segment
!= NULL
);
2141 value
-= tls_segment
->memsz();
2144 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2147 case elfcpp::R_X86_64_DTPOFF64
:
2148 if (optimized_type
== tls::TLSOPT_TO_LE
)
2150 // See R_X86_64_DTPOFF32, just above, for why we test this.
2151 if (this->saw_tls_block_reloc_
)
2153 gold_assert(tls_segment
!= NULL
);
2154 value
-= tls_segment
->memsz();
2157 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2160 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2161 if (optimized_type
== tls::TLSOPT_TO_LE
)
2163 gold_assert(tls_segment
!= NULL
);
2164 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2165 rela
, r_type
, value
, view
,
2169 else if (optimized_type
== tls::TLSOPT_NONE
)
2171 // Relocate the field with the offset of the GOT entry for
2172 // the tp-relative offset of the symbol.
2173 unsigned int got_offset
;
2176 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
2177 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
2178 - target
->got_size());
2182 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2183 gold_assert(object
->local_has_got_offset(r_sym
,
2184 GOT_TYPE_TLS_OFFSET
));
2185 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
2186 - target
->got_size());
2188 value
= target
->got_plt_section()->address() + got_offset
;
2189 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2192 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2193 _("unsupported reloc type %u"),
2197 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2198 value
-= tls_segment
->memsz();
2199 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2204 // Do a relocation in which we convert a TLS General-Dynamic to an
2208 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info
<64, false>* relinfo
,
2211 const elfcpp::Rela
<64, false>& rela
,
2213 elfcpp::Elf_types
<64>::Elf_Addr value
,
2214 unsigned char* view
,
2215 elfcpp::Elf_types
<64>::Elf_Addr address
,
2216 section_size_type view_size
)
2218 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2219 // .word 0x6666; rex64; call __tls_get_addr
2220 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2222 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2223 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2225 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2226 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2227 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2228 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2230 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2232 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2233 Relocate_functions
<64, false>::pcrela32(view
+ 8, value
, addend
- 8, address
);
2235 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2237 this->skip_call_tls_get_addr_
= true;
2240 // Do a relocation in which we convert a TLS General-Dynamic to a
2244 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
2246 Output_segment
* tls_segment
,
2247 const elfcpp::Rela
<64, false>& rela
,
2249 elfcpp::Elf_types
<64>::Elf_Addr value
,
2250 unsigned char* view
,
2251 section_size_type view_size
)
2253 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2254 // .word 0x6666; rex64; call __tls_get_addr
2255 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2257 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2258 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2260 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2261 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2262 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2263 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2265 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2267 value
-= tls_segment
->memsz();
2268 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
2270 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2272 this->skip_call_tls_get_addr_
= true;
2275 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2278 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2279 const Relocate_info
<64, false>* relinfo
,
2282 const elfcpp::Rela
<64, false>& rela
,
2283 unsigned int r_type
,
2284 elfcpp::Elf_types
<64>::Elf_Addr value
,
2285 unsigned char* view
,
2286 elfcpp::Elf_types
<64>::Elf_Addr address
,
2287 section_size_type view_size
)
2289 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2291 // leaq foo@tlsdesc(%rip), %rax
2292 // ==> movq foo@gottpoff(%rip), %rax
2293 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2294 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2295 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2296 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2298 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2299 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2303 // call *foo@tlscall(%rax)
2305 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2306 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2307 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2308 view
[0] == 0xff && view
[1] == 0x10);
2314 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2317 Target_x86_64::Relocate::tls_desc_gd_to_le(
2318 const Relocate_info
<64, false>* relinfo
,
2320 Output_segment
* tls_segment
,
2321 const elfcpp::Rela
<64, false>& rela
,
2322 unsigned int r_type
,
2323 elfcpp::Elf_types
<64>::Elf_Addr value
,
2324 unsigned char* view
,
2325 section_size_type view_size
)
2327 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2329 // leaq foo@tlsdesc(%rip), %rax
2330 // ==> movq foo@tpoff, %rax
2331 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2332 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2333 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2334 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2337 value
-= tls_segment
->memsz();
2338 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2342 // call *foo@tlscall(%rax)
2344 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2345 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2346 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2347 view
[0] == 0xff && view
[1] == 0x10);
2354 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
2357 const elfcpp::Rela
<64, false>& rela
,
2359 elfcpp::Elf_types
<64>::Elf_Addr
,
2360 unsigned char* view
,
2361 section_size_type view_size
)
2363 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2364 // ... leq foo@dtpoff(%rax),%reg
2365 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2367 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2368 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
2370 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2371 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
2373 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
2375 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
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_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
2388 Output_segment
* tls_segment
,
2389 const elfcpp::Rela
<64, false>& rela
,
2391 elfcpp::Elf_types
<64>::Elf_Addr value
,
2392 unsigned char* view
,
2393 section_size_type view_size
)
2395 // We need to examine the opcodes to figure out which instruction we
2398 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
2399 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
2401 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2402 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2404 unsigned char op1
= view
[-3];
2405 unsigned char op2
= view
[-2];
2406 unsigned char op3
= view
[-1];
2407 unsigned char reg
= op3
>> 3;
2415 view
[-1] = 0xc0 | reg
;
2419 // Special handling for %rsp.
2423 view
[-1] = 0xc0 | reg
;
2431 view
[-1] = 0x80 | reg
| (reg
<< 3);
2434 value
-= tls_segment
->memsz();
2435 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2438 // Relocate section data.
2441 Target_x86_64::relocate_section(
2442 const Relocate_info
<64, false>* relinfo
,
2443 unsigned int sh_type
,
2444 const unsigned char* prelocs
,
2446 Output_section
* output_section
,
2447 bool needs_special_offset_handling
,
2448 unsigned char* view
,
2449 elfcpp::Elf_types
<64>::Elf_Addr address
,
2450 section_size_type view_size
,
2451 const Reloc_symbol_changes
* reloc_symbol_changes
)
2453 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2455 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2456 Target_x86_64::Relocate
>(
2462 needs_special_offset_handling
,
2466 reloc_symbol_changes
);
2469 // Return the size of a relocation while scanning during a relocatable
2473 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2474 unsigned int r_type
,
2479 case elfcpp::R_X86_64_NONE
:
2480 case elfcpp::R_386_GNU_VTINHERIT
:
2481 case elfcpp::R_386_GNU_VTENTRY
:
2482 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2483 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2484 case elfcpp::R_X86_64_TLSDESC_CALL
:
2485 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2486 case elfcpp::R_X86_64_DTPOFF32
:
2487 case elfcpp::R_X86_64_DTPOFF64
:
2488 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2489 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2492 case elfcpp::R_X86_64_64
:
2493 case elfcpp::R_X86_64_PC64
:
2494 case elfcpp::R_X86_64_GOTOFF64
:
2495 case elfcpp::R_X86_64_GOTPC64
:
2496 case elfcpp::R_X86_64_PLTOFF64
:
2497 case elfcpp::R_X86_64_GOT64
:
2498 case elfcpp::R_X86_64_GOTPCREL64
:
2499 case elfcpp::R_X86_64_GOTPCREL
:
2500 case elfcpp::R_X86_64_GOTPLT64
:
2503 case elfcpp::R_X86_64_32
:
2504 case elfcpp::R_X86_64_32S
:
2505 case elfcpp::R_X86_64_PC32
:
2506 case elfcpp::R_X86_64_PLT32
:
2507 case elfcpp::R_X86_64_GOTPC32
:
2508 case elfcpp::R_X86_64_GOT32
:
2511 case elfcpp::R_X86_64_16
:
2512 case elfcpp::R_X86_64_PC16
:
2515 case elfcpp::R_X86_64_8
:
2516 case elfcpp::R_X86_64_PC8
:
2519 case elfcpp::R_X86_64_COPY
:
2520 case elfcpp::R_X86_64_GLOB_DAT
:
2521 case elfcpp::R_X86_64_JUMP_SLOT
:
2522 case elfcpp::R_X86_64_RELATIVE
:
2523 // These are outstanding tls relocs, which are unexpected when linking
2524 case elfcpp::R_X86_64_TPOFF64
:
2525 case elfcpp::R_X86_64_DTPMOD64
:
2526 case elfcpp::R_X86_64_TLSDESC
:
2527 object
->error(_("unexpected reloc %u in object file"), r_type
);
2530 case elfcpp::R_X86_64_SIZE32
:
2531 case elfcpp::R_X86_64_SIZE64
:
2533 object
->error(_("unsupported reloc %u against local symbol"), r_type
);
2538 // Scan the relocs during a relocatable link.
2541 Target_x86_64::scan_relocatable_relocs(Symbol_table
* symtab
,
2543 Sized_relobj
<64, false>* object
,
2544 unsigned int data_shndx
,
2545 unsigned int sh_type
,
2546 const unsigned char* prelocs
,
2548 Output_section
* output_section
,
2549 bool needs_special_offset_handling
,
2550 size_t local_symbol_count
,
2551 const unsigned char* plocal_symbols
,
2552 Relocatable_relocs
* rr
)
2554 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2556 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_RELA
,
2557 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2559 gold::scan_relocatable_relocs
<64, false, elfcpp::SHT_RELA
,
2560 Scan_relocatable_relocs
>(
2568 needs_special_offset_handling
,
2574 // Relocate a section during a relocatable link.
2577 Target_x86_64::relocate_for_relocatable(
2578 const Relocate_info
<64, false>* relinfo
,
2579 unsigned int sh_type
,
2580 const unsigned char* prelocs
,
2582 Output_section
* output_section
,
2583 off_t offset_in_output_section
,
2584 const Relocatable_relocs
* rr
,
2585 unsigned char* view
,
2586 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
2587 section_size_type view_size
,
2588 unsigned char* reloc_view
,
2589 section_size_type reloc_view_size
)
2591 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2593 gold::relocate_for_relocatable
<64, false, elfcpp::SHT_RELA
>(
2598 offset_in_output_section
,
2607 // Return the value to use for a dynamic which requires special
2608 // treatment. This is how we support equality comparisons of function
2609 // pointers across shared library boundaries, as described in the
2610 // processor specific ABI supplement.
2613 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
2615 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2616 return this->plt_section()->address() + gsym
->plt_offset();
2619 // Return a string used to fill a code section with nops to take up
2620 // the specified length.
2623 Target_x86_64::do_code_fill(section_size_type length
) const
2627 // Build a jmpq instruction to skip over the bytes.
2628 unsigned char jmp
[5];
2630 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2631 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2632 + std::string(length
- 5, '\0'));
2635 // Nop sequences of various lengths.
2636 const char nop1
[1] = { 0x90 }; // nop
2637 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2638 const char nop3
[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
2639 const char nop4
[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
2640 const char nop5
[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
2642 const char nop6
[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
2644 const char nop7
[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
2646 const char nop8
[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
2647 0x00, 0x00, 0x00, 0x00 };
2648 const char nop9
[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
2649 0x00, 0x00, 0x00, 0x00,
2651 const char nop10
[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
2652 0x84, 0x00, 0x00, 0x00,
2654 const char nop11
[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
2655 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2657 const char nop12
[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
2658 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
2659 0x00, 0x00, 0x00, 0x00 };
2660 const char nop13
[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2661 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
2662 0x00, 0x00, 0x00, 0x00,
2664 const char nop14
[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2665 0x66, 0x2e, 0x0f, 0x1f, // data16
2666 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2668 const char nop15
[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2669 0x66, 0x66, 0x2e, 0x0f, // data16; data16
2670 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2673 const char* nops
[16] = {
2675 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2676 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2679 return std::string(nops
[length
], length
);
2682 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2683 // compiled with -fstack-split. The function calls non-stack-split
2684 // code. We have to change the function so that it always ensures
2685 // that it has enough stack space to run some random function.
2688 Target_x86_64::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
2689 section_offset_type fnoffset
,
2690 section_size_type fnsize
,
2691 unsigned char* view
,
2692 section_size_type view_size
,
2694 std::string
* to
) const
2696 // The function starts with a comparison of the stack pointer and a
2697 // field in the TCB. This is followed by a jump.
2700 if (this->match_view(view
, view_size
, fnoffset
, "\x64\x48\x3b\x24\x25", 5)
2703 // We will call __morestack if the carry flag is set after this
2704 // comparison. We turn the comparison into an stc instruction
2706 view
[fnoffset
] = '\xf9';
2707 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 8);
2709 // lea NN(%rsp),%r10
2710 // lea NN(%rsp),%r11
2711 else if ((this->match_view(view
, view_size
, fnoffset
,
2712 "\x4c\x8d\x94\x24", 4)
2713 || this->match_view(view
, view_size
, fnoffset
,
2714 "\x4c\x8d\x9c\x24", 4))
2717 // This is loading an offset from the stack pointer for a
2718 // comparison. The offset is negative, so we decrease the
2719 // offset by the amount of space we need for the stack. This
2720 // means we will avoid calling __morestack if there happens to
2721 // be plenty of space on the stack already.
2722 unsigned char* pval
= view
+ fnoffset
+ 4;
2723 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
2724 val
-= parameters
->options().split_stack_adjust_size();
2725 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
2729 if (!object
->has_no_split_stack())
2730 object
->error(_("failed to match split-stack sequence at "
2731 "section %u offset %0zx"),
2732 shndx
, static_cast<size_t>(fnoffset
));
2736 // We have to change the function so that it calls
2737 // __morestack_non_split instead of __morestack. The former will
2738 // allocate additional stack space.
2739 *from
= "__morestack";
2740 *to
= "__morestack_non_split";
2743 // The selector for x86_64 object files.
2745 class Target_selector_x86_64
: public Target_selector_freebsd
2748 Target_selector_x86_64()
2749 : Target_selector_freebsd(elfcpp::EM_X86_64
, 64, false, "elf64-x86-64",
2750 "elf64-x86-64-freebsd")
2754 do_instantiate_target()
2755 { return new Target_x86_64(); }
2759 Target_selector_x86_64 target_selector_x86_64
;
2761 } // End anonymous namespace.