1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright 2006, 2007, 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
9 // modify it under the terms of the GNU Library General Public License
10 // as published by the Free Software Foundation; either version 2, or
11 // (at your option) any later version.
13 // In addition to the permissions in the GNU Library General Public
14 // License, the Free Software Foundation gives you unlimited
15 // permission to link the compiled version of this file into
16 // combinations with other programs, and to distribute those
17 // combinations without any restriction coming from the use of this
18 // file. (The Library Public License restrictions do apply in other
19 // respects; for example, they cover modification of the file, and
20 /// distribution when not linked into a combined executable.)
22 // This program is distributed in the hope that it will be useful, but
23 // WITHOUT ANY WARRANTY; without even the implied warranty of
24 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 // Library General Public License for more details.
27 // You should have received a copy of the GNU Library General Public
28 // License along with this program; if not, write to the Free Software
29 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
37 #include "parameters.h"
45 #include "target-reloc.h"
46 #include "target-select.h"
54 class Output_data_plt_x86_64
;
56 // The x86_64 target class.
58 // http://www.x86-64.org/documentation/abi.pdf
59 // TLS info comes from
60 // http://people.redhat.com/drepper/tls.pdf
61 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
63 class Target_x86_64
: public Sized_target
<64, false>
66 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
67 // uses only Elf64_Rela relocation entries with explicit addends."
68 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
71 : Sized_target
<64, false>(&x86_64_info
),
72 got_(NULL
), plt_(NULL
), got_plt_(NULL
), rela_dyn_(NULL
),
73 copy_relocs_(NULL
), dynbss_(NULL
)
76 // Scan the relocations to look for symbol adjustments.
78 scan_relocs(const General_options
& options
,
81 Sized_relobj
<64, false>* object
,
82 unsigned int data_shndx
,
84 const unsigned char* prelocs
,
86 size_t local_symbol_count
,
87 const unsigned char* plocal_symbols
,
88 Symbol
** global_symbols
);
90 // Finalize the sections.
92 do_finalize_sections(Layout
*);
94 // Return the value to use for a dynamic which requires special
97 do_dynsym_value(const Symbol
*) const;
99 // Relocate a section.
101 relocate_section(const Relocate_info
<64, false>*,
102 unsigned int sh_type
,
103 const unsigned char* prelocs
,
106 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
109 // Return a string used to fill a code section with nops.
111 do_code_fill(off_t length
);
114 // The class which scans relocations.
118 local(const General_options
& options
, Symbol_table
* symtab
,
119 Layout
* layout
, Target_x86_64
* target
,
120 Sized_relobj
<64, false>* object
,
121 unsigned int data_shndx
,
122 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
123 const elfcpp::Sym
<64, false>& lsym
);
126 global(const General_options
& options
, Symbol_table
* symtab
,
127 Layout
* layout
, Target_x86_64
* target
,
128 Sized_relobj
<64, false>* object
,
129 unsigned int data_shndx
,
130 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
134 unsupported_reloc_local(Sized_relobj
<64, false>*, unsigned int r_type
);
137 unsupported_reloc_global(Sized_relobj
<64, false>*, unsigned int r_type
,
141 // The class which implements relocation.
146 : skip_call_tls_get_addr_(false)
151 if (this->skip_call_tls_get_addr_
)
153 // FIXME: This needs to specify the location somehow.
154 gold_error(_("missing expected TLS relocation"));
158 // Do a relocation. Return false if the caller should not issue
159 // any warnings about this relocation.
161 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, size_t relnum
,
162 const elfcpp::Rela
<64, false>&,
163 unsigned int r_type
, const Sized_symbol
<64>*,
164 const Symbol_value
<64>*,
165 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
169 // Do a TLS relocation.
171 relocate_tls(const Relocate_info
<64, false>*, size_t relnum
,
172 const elfcpp::Rela
<64, false>&,
173 unsigned int r_type
, const Sized_symbol
<64>*,
174 const Symbol_value
<64>*,
175 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
, off_t
);
177 // Do a TLS Initial-Exec to Local-Exec transition.
179 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
180 Output_segment
* tls_segment
,
181 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
182 elfcpp::Elf_types
<64>::Elf_Addr value
,
186 // Do a TLS General-Dynamic to Local-Exec transition.
188 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
189 Output_segment
* tls_segment
,
190 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
191 elfcpp::Elf_types
<64>::Elf_Addr value
,
195 // Do a TLS Local-Dynamic to Local-Exec transition.
197 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
198 Output_segment
* tls_segment
,
199 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
200 elfcpp::Elf_types
<64>::Elf_Addr value
,
204 // This is set if we should skip the next reloc, which should be a
205 // PLT32 reloc against ___tls_get_addr.
206 bool skip_call_tls_get_addr_
;
209 // Adjust TLS relocation type based on the options and whether this
210 // is a local symbol.
211 static tls::Tls_optimization
212 optimize_tls_reloc(bool is_final
, int r_type
);
214 // Get the GOT section, creating it if necessary.
215 Output_data_got
<64, false>*
216 got_section(Symbol_table
*, Layout
*);
218 // Create a PLT entry for a global symbol.
220 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
222 // Get the PLT section.
223 Output_data_plt_x86_64
*
226 gold_assert(this->plt_
!= NULL
);
230 // Get the dynamic reloc section, creating it if necessary.
232 rela_dyn_section(Layout
*);
234 // Copy a relocation against a global symbol.
236 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
237 Sized_relobj
<64, false>*, unsigned int,
238 Symbol
*, const elfcpp::Rela
<64, false>&);
240 // Information about this specific target which we pass to the
241 // general Target structure.
242 static const Target::Target_info x86_64_info
;
245 Output_data_got
<64, false>* got_
;
247 Output_data_plt_x86_64
* plt_
;
248 // The GOT PLT section.
249 Output_data_space
* got_plt_
;
250 // The dynamic reloc section.
251 Reloc_section
* rela_dyn_
;
252 // Relocs saved to avoid a COPY reloc.
253 Copy_relocs
<64, false>* copy_relocs_
;
254 // Space for variables copied with a COPY reloc.
255 Output_data_space
* dynbss_
;
258 const Target::Target_info
Target_x86_64::x86_64_info
=
261 false, // is_big_endian
262 elfcpp::EM_X86_64
, // machine_code
263 false, // has_make_symbol
264 false, // has_resolve
265 true, // has_code_fill
266 "/lib/ld64.so.1", // program interpreter
267 0x400000, // text_segment_address
268 0x1000, // abi_pagesize
269 0x1000 // common_pagesize
272 // Get the GOT section, creating it if necessary.
274 Output_data_got
<64, false>*
275 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
277 if (this->got_
== NULL
)
279 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
281 this->got_
= new Output_data_got
<64, false>();
283 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
284 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
287 // The old GNU linker creates a .got.plt section. We just
288 // create another set of data in the .got section. Note that we
289 // always create a PLT if we create a GOT, although the PLT
291 // TODO(csilvers): do we really need an alignment of 8?
292 this->got_plt_
= new Output_data_space(8);
293 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
294 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
297 // The first three entries are reserved.
298 this->got_plt_
->set_space_size(3 * 8);
300 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
301 symtab
->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL
,
303 0, 0, elfcpp::STT_OBJECT
,
305 elfcpp::STV_HIDDEN
, 0,
312 // Get the dynamic reloc section, creating it if necessary.
314 Target_x86_64::Reloc_section
*
315 Target_x86_64::rela_dyn_section(Layout
* layout
)
317 if (this->rela_dyn_
== NULL
)
319 gold_assert(layout
!= NULL
);
320 this->rela_dyn_
= new Reloc_section();
321 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
322 elfcpp::SHF_ALLOC
, this->rela_dyn_
);
324 return this->rela_dyn_
;
327 // A class to handle the PLT data.
329 class Output_data_plt_x86_64
: public Output_section_data
332 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
334 Output_data_plt_x86_64(Layout
*, Output_data_space
*);
336 // Add an entry to the PLT.
338 add_entry(Symbol
* gsym
);
340 // Return the .rel.plt section data.
343 { return this->rel_
; }
347 do_adjust_output_section(Output_section
* os
);
350 // The size of an entry in the PLT.
351 static const int plt_entry_size
= 16;
353 // The first entry in the PLT.
354 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
355 // procedure linkage table for both programs and shared objects."
356 static unsigned char first_plt_entry
[plt_entry_size
];
358 // Other entries in the PLT for an executable.
359 static unsigned char plt_entry
[plt_entry_size
];
361 // Set the final size.
363 do_set_address(uint64_t, off_t
)
364 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
366 // Write out the PLT data.
368 do_write(Output_file
*);
370 // The reloc section.
372 // The .got.plt section.
373 Output_data_space
* got_plt_
;
374 // The number of PLT entries.
378 // Create the PLT section. The ordinary .got section is an argument,
379 // since we need to refer to the start. We also create our own .got
380 // section just for PLT entries.
382 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout
* layout
,
383 Output_data_space
* got_plt
)
384 // TODO(csilvers): do we really need an alignment of 8?
385 : Output_section_data(8), got_plt_(got_plt
), count_(0)
387 this->rel_
= new Reloc_section();
388 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
389 elfcpp::SHF_ALLOC
, this->rel_
);
393 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
395 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
396 // linker, and so do we.
400 // Add an entry to the PLT.
403 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
405 gold_assert(!gsym
->has_plt_offset());
407 // Note that when setting the PLT offset we skip the initial
408 // reserved PLT entry.
409 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
413 off_t got_offset
= this->got_plt_
->data_size();
415 // Every PLT entry needs a GOT entry which points back to the PLT
416 // entry (this will be changed by the dynamic linker, normally
417 // lazily when the function is called).
418 this->got_plt_
->set_space_size(got_offset
+ 8);
420 // Every PLT entry needs a reloc.
421 gsym
->set_needs_dynsym_entry();
422 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
425 // Note that we don't need to save the symbol. The contents of the
426 // PLT are independent of which symbols are used. The symbols only
427 // appear in the relocations.
430 // The first entry in the PLT for an executable.
432 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
434 // From AMD64 ABI Draft 0.98, page 76
435 0xff, 0x35, // pushq contents of memory address
436 0, 0, 0, 0, // replaced with address of .got + 4
437 0xff, 0x25, // jmp indirect
438 0, 0, 0, 0, // replaced with address of .got + 8
439 0x90, 0x90, 0x90, 0x90 // noop (x4)
442 // Subsequent entries in the PLT for an executable.
444 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
446 // From AMD64 ABI Draft 0.98, page 76
447 0xff, 0x25, // jmpq indirect
448 0, 0, 0, 0, // replaced with address of symbol in .got
449 0x68, // pushq immediate
450 0, 0, 0, 0, // replaced with offset into relocation table
451 0xe9, // jmpq relative
452 0, 0, 0, 0 // replaced with offset to start of .plt
455 // Write out the PLT. This uses the hand-coded instructions above,
456 // and adjusts them as needed. This is specified by the AMD64 ABI.
459 Output_data_plt_x86_64::do_write(Output_file
* of
)
461 const off_t offset
= this->offset();
462 const off_t oview_size
= this->data_size();
463 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
465 const off_t got_file_offset
= this->got_plt_
->offset();
466 const off_t got_size
= this->got_plt_
->data_size();
467 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
470 unsigned char* pov
= oview
;
472 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
473 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
475 memcpy(pov
, first_plt_entry
, plt_entry_size
);
476 if (!parameters
->output_is_shared())
478 // We do a jmp relative to the PC at the end of this instruction.
479 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 8
480 - (plt_address
+ 6));
481 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 16
482 - (plt_address
+ 12));
484 pov
+= plt_entry_size
;
486 unsigned char* got_pov
= got_view
;
488 memset(got_pov
, 0, 24);
491 unsigned int plt_offset
= plt_entry_size
;
492 unsigned int got_offset
= 24;
493 const unsigned int count
= this->count_
;
494 for (unsigned int plt_index
= 0;
497 pov
+= plt_entry_size
,
499 plt_offset
+= plt_entry_size
,
502 // Set and adjust the PLT entry itself.
503 memcpy(pov
, plt_entry
, plt_entry_size
);
504 if (parameters
->output_is_shared())
505 // FIXME(csilvers): what's the right thing to write here?
506 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
508 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
509 (got_address
+ got_offset
510 - (plt_address
+ plt_offset
513 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
514 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
515 - (plt_offset
+ plt_entry_size
));
517 // Set the entry in the GOT.
518 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
521 gold_assert(pov
- oview
== oview_size
);
522 gold_assert(got_pov
- got_view
== got_size
);
524 of
->write_output_view(offset
, oview_size
, oview
);
525 of
->write_output_view(got_file_offset
, got_size
, got_view
);
528 // Create a PLT entry for a global symbol.
531 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
534 if (gsym
->has_plt_offset())
537 if (this->plt_
== NULL
)
539 // Create the GOT sections first.
540 this->got_section(symtab
, layout
);
542 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_plt_
);
543 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
545 | elfcpp::SHF_EXECINSTR
),
549 this->plt_
->add_entry(gsym
);
552 // Handle a relocation against a non-function symbol defined in a
553 // dynamic object. The traditional way to handle this is to generate
554 // a COPY relocation to copy the variable at runtime from the shared
555 // object into the executable's data segment. However, this is
556 // undesirable in general, as if the size of the object changes in the
557 // dynamic object, the executable will no longer work correctly. If
558 // this relocation is in a writable section, then we can create a
559 // dynamic reloc and the dynamic linker will resolve it to the correct
560 // address at runtime. However, we do not want do that if the
561 // relocation is in a read-only section, as it would prevent the
562 // readonly segment from being shared. And if we have to eventually
563 // generate a COPY reloc, then any dynamic relocations will be
564 // useless. So this means that if this is a writable section, we need
565 // to save the relocation until we see whether we have to create a
566 // COPY relocation for this symbol for any other relocation.
569 Target_x86_64::copy_reloc(const General_options
* options
,
570 Symbol_table
* symtab
,
572 Sized_relobj
<64, false>* object
,
573 unsigned int data_shndx
, Symbol
* gsym
,
574 const elfcpp::Rela
<64, false>& rela
)
576 Sized_symbol
<64>* ssym
;
577 ssym
= symtab
->get_sized_symbol
SELECT_SIZE_NAME(64) (gsym
580 if (!Copy_relocs
<64, false>::need_copy_reloc(options
, object
,
583 // So far we do not need a COPY reloc. Save this relocation.
584 // If it turns out that we never need a COPY reloc for this
585 // symbol, then we will emit the relocation.
586 if (this->copy_relocs_
== NULL
)
587 this->copy_relocs_
= new Copy_relocs
<64, false>();
588 this->copy_relocs_
->save(ssym
, object
, data_shndx
, rela
);
592 // Allocate space for this symbol in the .bss section.
594 elfcpp::Elf_types
<64>::Elf_WXword symsize
= ssym
->symsize();
596 // There is no defined way to determine the required alignment
597 // of the symbol. We pick the alignment based on the size. We
598 // set an arbitrary maximum of 256.
600 for (align
= 1; align
< 512; align
<<= 1)
601 if ((symsize
& align
) != 0)
604 if (this->dynbss_
== NULL
)
606 this->dynbss_
= new Output_data_space(align
);
607 layout
->add_output_section_data(".bss",
610 | elfcpp::SHF_WRITE
),
614 Output_data_space
* dynbss
= this->dynbss_
;
616 if (align
> dynbss
->addralign())
617 dynbss
->set_space_alignment(align
);
619 off_t dynbss_size
= dynbss
->data_size();
620 dynbss_size
= align_address(dynbss_size
, align
);
621 off_t offset
= dynbss_size
;
622 dynbss
->set_space_size(dynbss_size
+ symsize
);
624 // Define the symbol in the .dynbss section.
625 symtab
->define_in_output_data(this, ssym
->name(), ssym
->version(),
626 dynbss
, offset
, symsize
, ssym
->type(),
627 ssym
->binding(), ssym
->visibility(),
628 ssym
->nonvis(), false, false);
630 // Add the COPY reloc.
631 ssym
->set_needs_dynsym_entry();
632 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
633 rela_dyn
->add_global(ssym
, elfcpp::R_X86_64_COPY
, dynbss
, offset
, 0);
638 // Optimize the TLS relocation type based on what we know about the
639 // symbol. IS_FINAL is true if the final address of this symbol is
640 // known at link time.
642 tls::Tls_optimization
643 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
645 // If we are generating a shared library, then we can't do anything
647 if (parameters
->output_is_shared())
648 return tls::TLSOPT_NONE
;
652 case elfcpp::R_X86_64_TLSGD
:
653 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
654 case elfcpp::R_X86_64_TLSDESC_CALL
:
655 // These are General-Dynamic which permits fully general TLS
656 // access. Since we know that we are generating an executable,
657 // we can convert this to Initial-Exec. If we also know that
658 // this is a local symbol, we can further switch to Local-Exec.
660 return tls::TLSOPT_TO_LE
;
661 return tls::TLSOPT_TO_IE
;
663 case elfcpp::R_X86_64_TLSLD
:
664 // This is Local-Dynamic, which refers to a local symbol in the
665 // dynamic TLS block. Since we know that we generating an
666 // executable, we can switch to Local-Exec.
667 return tls::TLSOPT_TO_LE
;
669 case elfcpp::R_X86_64_DTPOFF32
:
670 case elfcpp::R_X86_64_DTPOFF64
:
671 // Another Local-Dynamic reloc.
672 return tls::TLSOPT_TO_LE
;
674 case elfcpp::R_X86_64_GOTTPOFF
:
675 // These are Initial-Exec relocs which get the thread offset
676 // from the GOT. If we know that we are linking against the
677 // local symbol, we can switch to Local-Exec, which links the
678 // thread offset into the instruction.
680 return tls::TLSOPT_TO_LE
;
681 return tls::TLSOPT_NONE
;
683 case elfcpp::R_X86_64_TPOFF32
:
684 // When we already have Local-Exec, there is nothing further we
686 return tls::TLSOPT_NONE
;
693 // Report an unsupported relocation against a local symbol.
696 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
699 gold_error(_("%s: unsupported reloc %u against local symbol"),
700 object
->name().c_str(), r_type
);
703 // Scan a relocation for a local symbol.
706 Target_x86_64::Scan::local(const General_options
&,
707 Symbol_table
* symtab
,
709 Target_x86_64
* target
,
710 Sized_relobj
<64, false>* object
,
711 unsigned int data_shndx
,
712 const elfcpp::Rela
<64, false>& reloc
,
714 const elfcpp::Sym
<64, false>&)
718 case elfcpp::R_X86_64_NONE
:
719 case elfcpp::R_386_GNU_VTINHERIT
:
720 case elfcpp::R_386_GNU_VTENTRY
:
723 case elfcpp::R_X86_64_64
:
724 case elfcpp::R_X86_64_32
:
725 case elfcpp::R_X86_64_32S
:
726 case elfcpp::R_X86_64_16
:
727 case elfcpp::R_X86_64_8
:
728 // FIXME: If we are generating a shared object we need to copy
729 // this relocation into the object.
730 gold_assert(!parameters
->output_is_shared());
733 case elfcpp::R_X86_64_PC64
:
734 case elfcpp::R_X86_64_PC32
:
735 case elfcpp::R_X86_64_PC16
:
736 case elfcpp::R_X86_64_PC8
:
739 case elfcpp::R_X86_64_GOTPC32
: // TODO(csilvers): correct?
740 case elfcpp::R_X86_64_GOTOFF64
:
741 case elfcpp::R_X86_64_GOTPC64
: // TODO(csilvers): correct?
742 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): correct?
743 // We need a GOT section.
744 target
->got_section(symtab
, layout
);
747 case elfcpp::R_X86_64_GOT64
:
748 case elfcpp::R_X86_64_GOT32
:
749 case elfcpp::R_X86_64_GOTPCREL64
:
750 case elfcpp::R_X86_64_GOTPCREL
:
752 // The symbol requires a GOT entry.
753 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
754 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
755 if (got
->add_local(object
, r_sym
))
757 // If we are generating a shared object, we need to add a
758 // dynamic RELATIVE relocation for this symbol.
759 if (parameters
->output_is_shared())
761 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
762 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
763 data_shndx
, reloc
.get_r_offset(), 0);
769 case elfcpp::R_X86_64_COPY
:
770 case elfcpp::R_X86_64_GLOB_DAT
:
771 case elfcpp::R_X86_64_JUMP_SLOT
:
772 case elfcpp::R_X86_64_RELATIVE
:
773 // These are outstanding tls relocs, which are unexpected when linking
774 case elfcpp::R_X86_64_TPOFF64
:
775 case elfcpp::R_X86_64_DTPMOD64
:
776 case elfcpp::R_X86_64_TLSDESC
:
777 gold_error(_("%s: unexpected reloc %u in object file"),
778 object
->name().c_str(), r_type
);
781 // These are initial tls relocs, which are expected when linking
782 case elfcpp::R_X86_64_TLSGD
:
783 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
784 case elfcpp::R_X86_64_TLSDESC_CALL
:
785 case elfcpp::R_X86_64_TLSLD
:
786 case elfcpp::R_X86_64_GOTTPOFF
:
787 case elfcpp::R_X86_64_TPOFF32
:
788 case elfcpp::R_X86_64_DTPOFF32
:
789 case elfcpp::R_X86_64_DTPOFF64
:
791 bool output_is_shared
= parameters
->output_is_shared();
792 const tls::Tls_optimization optimized_type
793 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
796 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
797 // FIXME: If generating a shared object, we need to copy
798 // this relocation into the object.
799 gold_assert(!output_is_shared
);
802 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
803 // FIXME: If not relaxing to LE, we need to generate a
805 if (optimized_type
!= tls::TLSOPT_TO_LE
)
806 unsupported_reloc_local(object
, r_type
);
809 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
810 case elfcpp::R_X86_64_DTPOFF32
:
811 case elfcpp::R_X86_64_DTPOFF64
:
812 // FIXME: If not relaxing to LE, we need to generate a
814 if (optimized_type
!= tls::TLSOPT_TO_LE
)
815 unsupported_reloc_local(object
, r_type
);
819 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
820 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
821 case elfcpp::R_X86_64_TLSDESC_CALL
:
822 // FIXME: If not relaxing to LE, we need to generate
823 // DTPMOD64 and DTPOFF64 relocs.
824 if (optimized_type
!= tls::TLSOPT_TO_LE
)
825 unsupported_reloc_local(object
, r_type
);
834 case elfcpp::R_X86_64_GOTPLT64
:
835 case elfcpp::R_X86_64_PLT32
:
836 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
837 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
839 gold_error(_("%s: unsupported reloc %u against local symbol"),
840 object
->name().c_str(), r_type
);
846 // Report an unsupported relocation against a global symbol.
849 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
853 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
854 object
->name().c_str(), r_type
, gsym
->name());
857 // Scan a relocation for a global symbol.
860 Target_x86_64::Scan::global(const General_options
& options
,
861 Symbol_table
* symtab
,
863 Target_x86_64
* target
,
864 Sized_relobj
<64, false>* object
,
865 unsigned int data_shndx
,
866 const elfcpp::Rela
<64, false>& reloc
,
872 case elfcpp::R_X86_64_NONE
:
873 case elfcpp::R_386_GNU_VTINHERIT
:
874 case elfcpp::R_386_GNU_VTENTRY
:
877 case elfcpp::R_X86_64_64
:
878 case elfcpp::R_X86_64_PC64
:
879 case elfcpp::R_X86_64_32
:
880 case elfcpp::R_X86_64_32S
:
881 case elfcpp::R_X86_64_PC32
:
882 case elfcpp::R_X86_64_16
:
883 case elfcpp::R_X86_64_PC16
:
884 case elfcpp::R_X86_64_8
:
885 case elfcpp::R_X86_64_PC8
:
886 // FIXME: If we are generating a shared object we may need to
887 // copy this relocation into the object. If this symbol is
888 // defined in a shared object, we may need to copy this
889 // relocation in order to avoid a COPY relocation.
890 gold_assert(!parameters
->output_is_shared());
892 if (gsym
->is_from_dynobj())
894 // This symbol is defined in a dynamic object. If it is a
895 // function, we make a PLT entry. Otherwise we need to
896 // either generate a COPY reloc or copy this reloc.
897 if (gsym
->type() == elfcpp::STT_FUNC
)
899 target
->make_plt_entry(symtab
, layout
, gsym
);
901 // If this is not a PC relative reference, then we may
902 // be taking the address of the function. In that case
903 // we need to set the entry in the dynamic symbol table
904 // to the address of the PLT entry.
905 if (r_type
!= elfcpp::R_X86_64_PC64
906 && r_type
!= elfcpp::R_X86_64_PC32
907 && r_type
!= elfcpp::R_X86_64_PC16
908 && r_type
!= elfcpp::R_X86_64_PC8
)
909 gsym
->set_needs_dynsym_value();
912 target
->copy_reloc(&options
, symtab
, layout
, object
, data_shndx
,
918 case elfcpp::R_X86_64_GOT64
:
919 case elfcpp::R_X86_64_GOT32
:
920 case elfcpp::R_X86_64_GOTPCREL64
:
921 case elfcpp::R_X86_64_GOTPCREL
:
922 case elfcpp::R_X86_64_GOTPLT64
:
924 // The symbol requires a GOT entry.
925 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
926 if (got
->add_global(gsym
))
928 // If this symbol is not fully resolved, we need to add a
929 // dynamic relocation for it.
930 if (!gsym
->final_value_is_known())
932 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
933 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
, got
,
934 gsym
->got_offset(), 0);
940 case elfcpp::R_X86_64_PLT32
:
941 // If the symbol is fully resolved, this is just a PC32 reloc.
942 // Otherwise we need a PLT entry.
943 if (gsym
->final_value_is_known())
945 target
->make_plt_entry(symtab
, layout
, gsym
);
948 case elfcpp::R_X86_64_GOTPC32
: // TODO(csilvers): correct?
949 case elfcpp::R_X86_64_GOTOFF64
:
950 case elfcpp::R_X86_64_GOTPC64
: // TODO(csilvers): correct?
951 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): correct?
952 // We need a GOT section.
953 target
->got_section(symtab
, layout
);
956 case elfcpp::R_X86_64_COPY
:
957 case elfcpp::R_X86_64_GLOB_DAT
:
958 case elfcpp::R_X86_64_JUMP_SLOT
:
959 case elfcpp::R_X86_64_RELATIVE
:
960 // These are outstanding tls relocs, which are unexpected when linking
961 case elfcpp::R_X86_64_TPOFF64
:
962 case elfcpp::R_X86_64_DTPMOD64
:
963 case elfcpp::R_X86_64_TLSDESC
:
964 gold_error(_("%s: unexpected reloc %u in object file"),
965 object
->name().c_str(), r_type
);
968 // These are initial tls relocs, which are expected for global()
969 case elfcpp::R_X86_64_TLSGD
:
970 case elfcpp::R_X86_64_TLSLD
:
971 case elfcpp::R_X86_64_GOTTPOFF
:
972 case elfcpp::R_X86_64_TPOFF32
:
973 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
974 case elfcpp::R_X86_64_TLSDESC_CALL
:
975 case elfcpp::R_X86_64_DTPOFF32
:
976 case elfcpp::R_X86_64_DTPOFF64
:
978 const bool is_final
= gsym
->final_value_is_known();
979 const tls::Tls_optimization optimized_type
980 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
983 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
984 // FIXME: If generating a shared object, we need to copy
985 // this relocation into the object.
986 gold_assert(is_final
);
989 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
990 // FIXME: If not relaxing to LE, we need to generate a
992 if (optimized_type
!= tls::TLSOPT_TO_LE
)
993 unsupported_reloc_global(object
, r_type
, gsym
);
996 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
997 case elfcpp::R_X86_64_DTPOFF32
:
998 case elfcpp::R_X86_64_DTPOFF64
:
999 // FIXME: If not relaxing to LE, we need to generate a
1001 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1002 unsupported_reloc_global(object
, r_type
, gsym
);
1006 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1007 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1008 case elfcpp::R_X86_64_TLSDESC_CALL
:
1009 // FIXME: If not relaxing to LE, we need to generate
1010 // DTPMOD64 and DTPOFF64, or TLSDESC, relocs.
1011 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1012 unsupported_reloc_global(object
, r_type
, gsym
);
1020 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
1021 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
1023 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1024 object
->name().c_str(), r_type
, gsym
->name());
1029 // Scan relocations for a section.
1032 Target_x86_64::scan_relocs(const General_options
& options
,
1033 Symbol_table
* symtab
,
1035 Sized_relobj
<64, false>* object
,
1036 unsigned int data_shndx
,
1037 unsigned int sh_type
,
1038 const unsigned char* prelocs
,
1040 size_t local_symbol_count
,
1041 const unsigned char* plocal_symbols
,
1042 Symbol
** global_symbols
)
1044 if (sh_type
== elfcpp::SHT_REL
)
1046 gold_error(_("%s: unsupported REL reloc section"),
1047 object
->name().c_str());
1051 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1052 Target_x86_64::Scan
>(
1066 // Finalize the sections.
1069 Target_x86_64::do_finalize_sections(Layout
* layout
)
1071 // Fill in some more dynamic tags.
1072 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1075 if (this->got_plt_
!= NULL
)
1076 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1078 if (this->plt_
!= NULL
)
1080 const Output_data
* od
= this->plt_
->rel_plt();
1081 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1082 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1083 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_RELA
);
1086 if (this->rela_dyn_
!= NULL
)
1088 const Output_data
* od
= this->rela_dyn_
;
1089 odyn
->add_section_address(elfcpp::DT_RELA
, od
);
1090 odyn
->add_section_size(elfcpp::DT_RELASZ
, od
);
1091 odyn
->add_constant(elfcpp::DT_RELAENT
,
1092 elfcpp::Elf_sizes
<64>::rela_size
);
1095 if (!parameters
->output_is_shared())
1097 // The value of the DT_DEBUG tag is filled in by the dynamic
1098 // linker at run time, and used by the debugger.
1099 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1103 // Emit any relocs we saved in an attempt to avoid generating COPY
1105 if (this->copy_relocs_
== NULL
)
1107 if (this->copy_relocs_
->any_to_emit())
1109 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1110 this->copy_relocs_
->emit(rela_dyn
);
1112 delete this->copy_relocs_
;
1113 this->copy_relocs_
= NULL
;
1116 // Perform a relocation.
1119 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1120 Target_x86_64
* target
,
1122 const elfcpp::Rela
<64, false>& rela
,
1123 unsigned int r_type
,
1124 const Sized_symbol
<64>* gsym
,
1125 const Symbol_value
<64>* psymval
,
1126 unsigned char* view
,
1127 elfcpp::Elf_types
<64>::Elf_Addr address
,
1130 if (this->skip_call_tls_get_addr_
)
1132 if (r_type
!= elfcpp::R_X86_64_PLT32
1134 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1136 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1137 _("missing expected TLS relocation"));
1141 this->skip_call_tls_get_addr_
= false;
1146 // Pick the value to use for symbols defined in shared objects.
1147 Symbol_value
<64> symval
;
1148 if (gsym
!= NULL
&& gsym
->is_from_dynobj() && gsym
->has_plt_offset())
1150 symval
.set_output_value(target
->plt_section()->address()
1151 + gsym
->plt_offset());
1155 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1156 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1158 // Get the GOT offset if needed.
1159 bool have_got_offset
= false;
1160 unsigned int got_offset
= 0;
1163 case elfcpp::R_X86_64_GOT32
:
1164 case elfcpp::R_X86_64_GOT64
:
1165 case elfcpp::R_X86_64_GOTPLT64
:
1166 case elfcpp::R_X86_64_GOTPCREL
:
1167 case elfcpp::R_X86_64_GOTPCREL64
:
1170 gold_assert(gsym
->has_got_offset());
1171 got_offset
= gsym
->got_offset();
1175 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1176 got_offset
= object
->local_got_offset(r_sym
);
1178 have_got_offset
= true;
1187 case elfcpp::R_X86_64_NONE
:
1188 case elfcpp::R_386_GNU_VTINHERIT
:
1189 case elfcpp::R_386_GNU_VTENTRY
:
1192 case elfcpp::R_X86_64_64
:
1193 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1196 case elfcpp::R_X86_64_PC64
:
1197 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1201 case elfcpp::R_X86_64_32
:
1202 // FIXME: we need to verify that value + addend fits into 32 bits:
1203 // uint64_t x = value + addend;
1204 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1205 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1206 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1209 case elfcpp::R_X86_64_32S
:
1210 // FIXME: we need to verify that value + addend fits into 32 bits:
1211 // int64_t x = value + addend; // note this quantity is signed!
1212 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1213 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1216 case elfcpp::R_X86_64_PC32
:
1217 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1221 case elfcpp::R_X86_64_16
:
1222 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
1225 case elfcpp::R_X86_64_PC16
:
1226 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
1230 case elfcpp::R_X86_64_8
:
1231 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
1234 case elfcpp::R_X86_64_PC8
:
1235 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
1239 case elfcpp::R_X86_64_PLT32
:
1240 gold_assert(gsym
->has_plt_offset()
1241 || gsym
->final_value_is_known());
1242 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1246 case elfcpp::R_X86_64_GOT32
:
1247 gold_assert(have_got_offset
);
1248 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
1251 case elfcpp::R_X86_64_GOTPC32
:
1254 elfcpp::Elf_types
<64>::Elf_Addr value
;
1255 value
= target
->got_section(NULL
, NULL
)->address();
1256 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1260 case elfcpp::R_X86_64_GOT64
:
1261 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1262 // Since we always add a PLT entry, this is equivalent.
1263 case elfcpp::R_X86_64_GOTPLT64
: // TODO(csilvers): correct?
1264 gold_assert(have_got_offset
);
1265 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
1268 case elfcpp::R_X86_64_GOTPC64
:
1271 elfcpp::Elf_types
<64>::Elf_Addr value
;
1272 value
= target
->got_section(NULL
, NULL
)->address();
1273 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1277 case elfcpp::R_X86_64_GOTOFF64
:
1279 elfcpp::Elf_types
<64>::Elf_Addr value
;
1280 value
= (psymval
->value(object
, 0)
1281 - target
->got_section(NULL
, NULL
)->address());
1282 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
1286 case elfcpp::R_X86_64_GOTPCREL
:
1288 gold_assert(have_got_offset
);
1289 elfcpp::Elf_types
<64>::Elf_Addr value
;
1290 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1291 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1295 case elfcpp::R_X86_64_GOTPCREL64
:
1297 gold_assert(have_got_offset
);
1298 elfcpp::Elf_types
<64>::Elf_Addr value
;
1299 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1300 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1304 case elfcpp::R_X86_64_COPY
:
1305 case elfcpp::R_X86_64_GLOB_DAT
:
1306 case elfcpp::R_X86_64_JUMP_SLOT
:
1307 case elfcpp::R_X86_64_RELATIVE
:
1308 // These are outstanding tls relocs, which are unexpected when linking
1309 case elfcpp::R_X86_64_TPOFF64
:
1310 case elfcpp::R_X86_64_DTPMOD64
:
1311 case elfcpp::R_X86_64_TLSDESC
:
1312 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1313 _("unexpected reloc %u in object file"),
1317 // These are initial tls relocs, which are expected when linking
1318 case elfcpp::R_X86_64_TLSGD
:
1319 case elfcpp::R_X86_64_TLSLD
:
1320 case elfcpp::R_X86_64_GOTTPOFF
:
1321 case elfcpp::R_X86_64_TPOFF32
:
1322 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1323 case elfcpp::R_X86_64_TLSDESC_CALL
:
1324 case elfcpp::R_X86_64_DTPOFF32
:
1325 case elfcpp::R_X86_64_DTPOFF64
:
1326 this->relocate_tls(relinfo
, relnum
, rela
, r_type
, gsym
, psymval
, view
,
1327 address
, view_size
);
1330 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
1331 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
1332 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): implement me!
1334 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1335 _("unsupported reloc %u"),
1343 // Perform a TLS relocation.
1346 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
1348 const elfcpp::Rela
<64, false>& rela
,
1349 unsigned int r_type
,
1350 const Sized_symbol
<64>* gsym
,
1351 const Symbol_value
<64>* psymval
,
1352 unsigned char* view
,
1353 elfcpp::Elf_types
<64>::Elf_Addr
,
1356 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1357 if (tls_segment
== NULL
)
1359 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1360 _("TLS reloc but no TLS segment"));
1364 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1366 const bool is_final
= (gsym
== NULL
1367 ? !parameters
->output_is_shared()
1368 : gsym
->final_value_is_known());
1369 const tls::Tls_optimization optimized_type
1370 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1373 case elfcpp::R_X86_64_TPOFF32
: // Local-exec reloc
1374 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1375 Relocate_functions
<64, false>::rel32(view
, value
);
1378 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec reloc
1379 if (optimized_type
== tls::TLSOPT_TO_LE
)
1381 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1382 rela
, r_type
, value
, view
,
1386 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1387 _("unsupported reloc type %u"),
1391 case elfcpp::R_X86_64_TLSGD
:
1392 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1393 case elfcpp::R_X86_64_TLSDESC_CALL
:
1394 if (optimized_type
== tls::TLSOPT_TO_LE
)
1396 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1397 rela
, r_type
, value
, view
,
1401 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1402 _("unsupported reloc %u"), r_type
);
1405 case elfcpp::R_X86_64_TLSLD
:
1406 if (optimized_type
== tls::TLSOPT_TO_LE
)
1408 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
1409 value
, view
, view_size
);
1412 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1413 _("unsupported reloc %u"), r_type
);
1416 case elfcpp::R_X86_64_DTPOFF32
:
1417 if (optimized_type
== tls::TLSOPT_TO_LE
)
1418 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1420 value
= value
- tls_segment
->vaddr();
1421 Relocate_functions
<64, false>::rel32(view
, value
);
1424 case elfcpp::R_X86_64_DTPOFF64
:
1425 if (optimized_type
== tls::TLSOPT_TO_LE
)
1426 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1428 value
= value
- tls_segment
->vaddr();
1429 Relocate_functions
<64, false>::rel64(view
, value
);
1434 // Do a relocation in which we convert a TLS Initial-Exec to a
1438 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
1440 Output_segment
* tls_segment
,
1441 const elfcpp::Rela
<64, false>& rela
,
1443 elfcpp::Elf_types
<64>::Elf_Addr value
,
1444 unsigned char* view
,
1447 // We need to examine the opcodes to figure out which instruction we
1450 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
1451 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
1453 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
1454 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
1456 unsigned char op1
= view
[-3];
1457 unsigned char op2
= view
[-2];
1458 unsigned char op3
= view
[-1];
1459 unsigned char reg
= op3
>> 3;
1467 view
[-1] = 0xc0 | reg
;
1471 // Special handling for %rsp.
1475 view
[-1] = 0xc0 | reg
;
1483 view
[-1] = 0x80 | reg
| (reg
<< 3);
1486 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1487 Relocate_functions
<64, false>::rela32(view
, value
, 0);
1490 // Do a relocation in which we convert a TLS General-Dynamic to a
1494 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
1496 Output_segment
* tls_segment
,
1497 const elfcpp::Rela
<64, false>& rela
,
1499 elfcpp::Elf_types
<64>::Elf_Addr value
,
1500 unsigned char* view
,
1503 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
1504 // .word 0x6666; rex64; call __tls_get_addr
1505 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
1507 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
1508 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
1510 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1511 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
1512 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1513 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
1515 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
1517 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1518 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
1520 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1522 this->skip_call_tls_get_addr_
= true;
1526 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
1529 const elfcpp::Rela
<64, false>& rela
,
1531 elfcpp::Elf_types
<64>::Elf_Addr
,
1532 unsigned char* view
,
1535 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
1536 // ... leq foo@dtpoff(%rax),%reg
1537 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
1539 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
1540 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
1542 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1543 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
1545 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
1547 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
1549 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1551 this->skip_call_tls_get_addr_
= true;
1554 // Relocate section data.
1557 Target_x86_64::relocate_section(const Relocate_info
<64, false>* relinfo
,
1558 unsigned int sh_type
,
1559 const unsigned char* prelocs
,
1561 unsigned char* view
,
1562 elfcpp::Elf_types
<64>::Elf_Addr address
,
1565 gold_assert(sh_type
== elfcpp::SHT_RELA
);
1567 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1568 Target_x86_64::Relocate
>(
1578 // Return the value to use for a dynamic which requires special
1579 // treatment. This is how we support equality comparisons of function
1580 // pointers across shared library boundaries, as described in the
1581 // processor specific ABI supplement.
1584 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
1586 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
1587 return this->plt_section()->address() + gsym
->plt_offset();
1590 // Return a string used to fill a code section with nops to take up
1591 // the specified length.
1594 Target_x86_64::do_code_fill(off_t length
)
1598 // Build a jmpq instruction to skip over the bytes.
1599 unsigned char jmp
[5];
1601 elfcpp::Swap_unaligned
<64, false>::writeval(jmp
+ 1, length
- 5);
1602 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
1603 + std::string(length
- 5, '\0'));
1606 // Nop sequences of various lengths.
1607 const char nop1
[1] = { 0x90 }; // nop
1608 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
1609 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1610 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1611 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1612 0x00 }; // leal 0(%esi,1),%esi
1613 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1615 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1617 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1618 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1619 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1620 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1622 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1623 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1625 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1626 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1628 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1629 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1630 0x00, 0x00, 0x00, 0x00 };
1631 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1632 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1633 0x27, 0x00, 0x00, 0x00,
1635 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1636 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1637 0xbc, 0x27, 0x00, 0x00,
1639 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1640 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1641 0x90, 0x90, 0x90, 0x90,
1644 const char* nops
[16] = {
1646 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
1647 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
1650 return std::string(nops
[length
], length
);
1653 // The selector for x86_64 object files.
1655 class Target_selector_x86_64
: public Target_selector
1658 Target_selector_x86_64()
1659 : Target_selector(elfcpp::EM_X86_64
, 64, false)
1663 recognize(int machine
, int osabi
, int abiversion
);
1666 Target_x86_64
* target_
;
1669 // Recognize an x86_64 object file when we already know that the machine
1670 // number is EM_X86_64.
1673 Target_selector_x86_64::recognize(int, int, int)
1675 if (this->target_
== NULL
)
1676 this->target_
= new Target_x86_64();
1677 return this->target_
;
1680 Target_selector_x86_64 target_selector_x86_64
;
1682 } // End anonymous namespace.