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 // Check the range for a TLS relocation.
197 check_range(const Relocate_info
<64, false>*, size_t relnum
,
198 const elfcpp::Rela
<64, false>&, off_t
, off_t
);
200 // Check the validity of a TLS relocation. This is like assert.
202 check_tls(const Relocate_info
<64, false>*, size_t relnum
,
203 const elfcpp::Rela
<64, false>&, bool);
205 // This is set if we should skip the next reloc, which should be a
206 // PLT32 reloc against ___tls_get_addr.
207 bool skip_call_tls_get_addr_
;
210 // Adjust TLS relocation type based on the options and whether this
211 // is a local symbol.
212 static tls::Tls_optimization
213 optimize_tls_reloc(bool is_final
, int r_type
);
215 // Get the GOT section, creating it if necessary.
216 Output_data_got
<64, false>*
217 got_section(Symbol_table
*, Layout
*);
219 // Create a PLT entry for a global symbol.
221 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
223 // Get the PLT section.
224 Output_data_plt_x86_64
*
227 gold_assert(this->plt_
!= NULL
);
231 // Get the dynamic reloc section, creating it if necessary.
233 rela_dyn_section(Layout
*);
235 // Copy a relocation against a global symbol.
237 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
238 Sized_relobj
<64, false>*, unsigned int,
239 Symbol
*, const elfcpp::Rela
<64, false>&);
241 // Information about this specific target which we pass to the
242 // general Target structure.
243 static const Target::Target_info x86_64_info
;
246 Output_data_got
<64, false>* got_
;
248 Output_data_plt_x86_64
* plt_
;
249 // The GOT PLT section.
250 Output_data_space
* got_plt_
;
251 // The dynamic reloc section.
252 Reloc_section
* rela_dyn_
;
253 // Relocs saved to avoid a COPY reloc.
254 Copy_relocs
<64, false>* copy_relocs_
;
255 // Space for variables copied with a COPY reloc.
256 Output_data_space
* dynbss_
;
259 const Target::Target_info
Target_x86_64::x86_64_info
=
262 false, // is_big_endian
263 elfcpp::EM_X86_64
, // machine_code
264 false, // has_make_symbol
265 false, // has_resolve
266 true, // has_code_fill
267 "/lib/ld64.so.1", // program interpreter
268 0x400000, // text_segment_address
269 0x1000, // abi_pagesize
270 0x1000 // common_pagesize
273 // Get the GOT section, creating it if necessary.
275 Output_data_got
<64, false>*
276 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
278 if (this->got_
== NULL
)
280 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
282 this->got_
= new Output_data_got
<64, false>();
284 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
285 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
288 // The old GNU linker creates a .got.plt section. We just
289 // create another set of data in the .got section. Note that we
290 // always create a PLT if we create a GOT, although the PLT
292 // TODO(csilvers): do we really need an alignment of 8?
293 this->got_plt_
= new Output_data_space(8);
294 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
295 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
298 // The first three entries are reserved.
299 this->got_plt_
->set_space_size(3 * 8);
301 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
302 symtab
->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL
,
304 0, 0, elfcpp::STT_OBJECT
,
306 elfcpp::STV_HIDDEN
, 0,
313 // Get the dynamic reloc section, creating it if necessary.
315 Target_x86_64::Reloc_section
*
316 Target_x86_64::rela_dyn_section(Layout
* layout
)
318 if (this->rela_dyn_
== NULL
)
320 gold_assert(layout
!= NULL
);
321 this->rela_dyn_
= new Reloc_section();
322 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
323 elfcpp::SHF_ALLOC
, this->rela_dyn_
);
325 return this->rela_dyn_
;
328 // A class to handle the PLT data.
330 class Output_data_plt_x86_64
: public Output_section_data
333 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
335 Output_data_plt_x86_64(Layout
*, Output_data_space
*);
337 // Add an entry to the PLT.
339 add_entry(Symbol
* gsym
);
341 // Return the .rel.plt section data.
344 { return this->rel_
; }
348 do_adjust_output_section(Output_section
* os
);
351 // The size of an entry in the PLT.
352 static const int plt_entry_size
= 16;
354 // The first entry in the PLT.
355 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
356 // procedure linkage table for both programs and shared objects."
357 static unsigned char first_plt_entry
[plt_entry_size
];
359 // Other entries in the PLT for an executable.
360 static unsigned char plt_entry
[plt_entry_size
];
362 // Set the final size.
364 do_set_address(uint64_t, off_t
)
365 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
367 // Write out the PLT data.
369 do_write(Output_file
*);
371 // The reloc section.
373 // The .got.plt section.
374 Output_data_space
* got_plt_
;
375 // The number of PLT entries.
379 // Create the PLT section. The ordinary .got section is an argument,
380 // since we need to refer to the start. We also create our own .got
381 // section just for PLT entries.
383 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout
* layout
,
384 Output_data_space
* got_plt
)
385 // TODO(csilvers): do we really need an alignment of 8?
386 : Output_section_data(8), got_plt_(got_plt
), count_(0)
388 this->rel_
= new Reloc_section();
389 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
390 elfcpp::SHF_ALLOC
, this->rel_
);
394 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
396 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
397 // linker, and so do we.
401 // Add an entry to the PLT.
404 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
406 gold_assert(!gsym
->has_plt_offset());
408 // Note that when setting the PLT offset we skip the initial
409 // reserved PLT entry.
410 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
414 off_t got_offset
= this->got_plt_
->data_size();
416 // Every PLT entry needs a GOT entry which points back to the PLT
417 // entry (this will be changed by the dynamic linker, normally
418 // lazily when the function is called).
419 this->got_plt_
->set_space_size(got_offset
+ 8);
421 // Every PLT entry needs a reloc.
422 gsym
->set_needs_dynsym_entry();
423 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
426 // Note that we don't need to save the symbol. The contents of the
427 // PLT are independent of which symbols are used. The symbols only
428 // appear in the relocations.
431 // The first entry in the PLT for an executable.
433 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
435 // From AMD64 ABI Draft 0.98, page 76
436 0xff, 0x35, // pushq contents of memory address
437 0, 0, 0, 0, // replaced with address of .got + 4
438 0xff, 0x25, // jmp indirect
439 0, 0, 0, 0, // replaced with address of .got + 8
440 0x90, 0x90, 0x90, 0x90 // noop (x4)
443 // Subsequent entries in the PLT for an executable.
445 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
447 // From AMD64 ABI Draft 0.98, page 76
448 0xff, 0x25, // jmpq indirect
449 0, 0, 0, 0, // replaced with address of symbol in .got
450 0x68, // pushq immediate
451 0, 0, 0, 0, // replaced with offset into relocation table
452 0xe9, // jmpq relative
453 0, 0, 0, 0 // replaced with offset to start of .plt
456 // Write out the PLT. This uses the hand-coded instructions above,
457 // and adjusts them as needed. This is specified by the AMD64 ABI.
460 Output_data_plt_x86_64::do_write(Output_file
* of
)
462 const off_t offset
= this->offset();
463 const off_t oview_size
= this->data_size();
464 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
466 const off_t got_file_offset
= this->got_plt_
->offset();
467 const off_t got_size
= this->got_plt_
->data_size();
468 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
471 unsigned char* pov
= oview
;
473 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
474 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
476 memcpy(pov
, first_plt_entry
, plt_entry_size
);
477 if (!parameters
->output_is_shared())
479 // We do a jmp relative to the PC at the end of this instruction.
480 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 8
481 - (plt_address
+ 6));
482 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 16
483 - (plt_address
+ 12));
485 pov
+= plt_entry_size
;
487 unsigned char* got_pov
= got_view
;
489 memset(got_pov
, 0, 24);
492 unsigned int plt_offset
= plt_entry_size
;
493 unsigned int got_offset
= 24;
494 const unsigned int count
= this->count_
;
495 for (unsigned int plt_index
= 0;
498 pov
+= plt_entry_size
,
500 plt_offset
+= plt_entry_size
,
503 // Set and adjust the PLT entry itself.
504 memcpy(pov
, plt_entry
, plt_entry_size
);
505 if (parameters
->output_is_shared())
506 // FIXME(csilvers): what's the right thing to write here?
507 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
509 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
510 (got_address
+ got_offset
511 - (plt_address
+ plt_offset
514 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
515 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
516 - (plt_offset
+ plt_entry_size
));
518 // Set the entry in the GOT.
519 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
522 gold_assert(pov
- oview
== oview_size
);
523 gold_assert(got_pov
- got_view
== got_size
);
525 of
->write_output_view(offset
, oview_size
, oview
);
526 of
->write_output_view(got_file_offset
, got_size
, got_view
);
529 // Create a PLT entry for a global symbol.
532 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
535 if (gsym
->has_plt_offset())
538 if (this->plt_
== NULL
)
540 // Create the GOT sections first.
541 this->got_section(symtab
, layout
);
543 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_plt_
);
544 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
546 | elfcpp::SHF_EXECINSTR
),
550 this->plt_
->add_entry(gsym
);
553 // Handle a relocation against a non-function symbol defined in a
554 // dynamic object. The traditional way to handle this is to generate
555 // a COPY relocation to copy the variable at runtime from the shared
556 // object into the executable's data segment. However, this is
557 // undesirable in general, as if the size of the object changes in the
558 // dynamic object, the executable will no longer work correctly. If
559 // this relocation is in a writable section, then we can create a
560 // dynamic reloc and the dynamic linker will resolve it to the correct
561 // address at runtime. However, we do not want do that if the
562 // relocation is in a read-only section, as it would prevent the
563 // readonly segment from being shared. And if we have to eventually
564 // generate a COPY reloc, then any dynamic relocations will be
565 // useless. So this means that if this is a writable section, we need
566 // to save the relocation until we see whether we have to create a
567 // COPY relocation for this symbol for any other relocation.
570 Target_x86_64::copy_reloc(const General_options
* options
,
571 Symbol_table
* symtab
,
573 Sized_relobj
<64, false>* object
,
574 unsigned int data_shndx
, Symbol
* gsym
,
575 const elfcpp::Rela
<64, false>& rel
)
577 Sized_symbol
<64>* ssym
;
578 ssym
= symtab
->get_sized_symbol
SELECT_SIZE_NAME(64) (gsym
581 if (!Copy_relocs
<64, false>::need_copy_reloc(options
, object
,
584 // So far we do not need a COPY reloc. Save this relocation.
585 // If it turns out that we never need a COPY reloc for this
586 // symbol, then we will emit the relocation.
587 if (this->copy_relocs_
== NULL
)
588 this->copy_relocs_
= new Copy_relocs
<64, false>();
589 this->copy_relocs_
->save(ssym
, object
, data_shndx
, rel
);
593 // Allocate space for this symbol in the .bss section.
595 elfcpp::Elf_types
<64>::Elf_WXword symsize
= ssym
->symsize();
597 // There is no defined way to determine the required alignment
598 // of the symbol. We pick the alignment based on the size. We
599 // set an arbitrary maximum of 256.
601 for (align
= 1; align
< 512; align
<<= 1)
602 if ((symsize
& align
) != 0)
605 if (this->dynbss_
== NULL
)
607 this->dynbss_
= new Output_data_space(align
);
608 layout
->add_output_section_data(".bss",
611 | elfcpp::SHF_WRITE
),
615 Output_data_space
* dynbss
= this->dynbss_
;
617 if (align
> dynbss
->addralign())
618 dynbss
->set_space_alignment(align
);
620 off_t dynbss_size
= dynbss
->data_size();
621 dynbss_size
= align_address(dynbss_size
, align
);
622 off_t offset
= dynbss_size
;
623 dynbss
->set_space_size(dynbss_size
+ symsize
);
625 // Define the symbol in the .dynbss section.
626 symtab
->define_in_output_data(this, ssym
->name(), ssym
->version(),
627 dynbss
, offset
, symsize
, ssym
->type(),
628 ssym
->binding(), ssym
->visibility(),
629 ssym
->nonvis(), false, false);
631 // Add the COPY reloc.
632 ssym
->set_needs_dynsym_entry();
633 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
634 rela_dyn
->add_global(ssym
, elfcpp::R_X86_64_COPY
, dynbss
, offset
, 0);
639 // Optimize the TLS relocation type based on what we know about the
640 // symbol. IS_FINAL is true if the final address of this symbol is
641 // known at link time.
643 tls::Tls_optimization
644 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
646 // If we are generating a shared library, then we can't do anything
648 if (parameters
->output_is_shared())
649 return tls::TLSOPT_NONE
;
653 case elfcpp::R_X86_64_TLSGD
:
654 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
655 case elfcpp::R_X86_64_TLSDESC_CALL
:
656 // These are General-Dynamic which permits fully general TLS
657 // access. Since we know that we are generating an executable,
658 // we can convert this to Initial-Exec. If we also know that
659 // this is a local symbol, we can further switch to Local-Exec.
661 return tls::TLSOPT_TO_LE
;
662 return tls::TLSOPT_TO_IE
;
664 case elfcpp::R_X86_64_TLSLD
:
665 // This is Local-Dynamic, which refers to a local symbol in the
666 // dynamic TLS block. Since we know that we generating an
667 // executable, we can switch to Local-Exec.
668 return tls::TLSOPT_TO_LE
;
670 case elfcpp::R_X86_64_DTPOFF32
:
671 case elfcpp::R_X86_64_DTPOFF64
:
672 // Another Local-Dynamic reloc.
673 return tls::TLSOPT_TO_LE
;
675 case elfcpp::R_X86_64_GOTTPOFF
:
676 // These are Initial-Exec relocs which get the thread offset
677 // from the GOT. If we know that we are linking against the
678 // local symbol, we can switch to Local-Exec, which links the
679 // thread offset into the instruction.
681 return tls::TLSOPT_TO_LE
;
682 return tls::TLSOPT_NONE
;
684 case elfcpp::R_X86_64_TPOFF32
:
685 // When we already have Local-Exec, there is nothing further we
687 return tls::TLSOPT_NONE
;
694 // Report an unsupported relocation against a local symbol.
697 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
700 gold_error(_("%s: unsupported reloc %u against local symbol"),
701 object
->name().c_str(), r_type
);
704 // Scan a relocation for a local symbol.
707 Target_x86_64::Scan::local(const General_options
&,
708 Symbol_table
* symtab
,
710 Target_x86_64
* target
,
711 Sized_relobj
<64, false>* object
,
712 unsigned int data_shndx
,
713 const elfcpp::Rela
<64, false>& reloc
,
715 const elfcpp::Sym
<64, false>&)
719 case elfcpp::R_X86_64_NONE
:
720 case elfcpp::R_386_GNU_VTINHERIT
:
721 case elfcpp::R_386_GNU_VTENTRY
:
724 case elfcpp::R_X86_64_64
:
725 case elfcpp::R_X86_64_32
:
726 case elfcpp::R_X86_64_32S
:
727 case elfcpp::R_X86_64_16
:
728 case elfcpp::R_X86_64_8
:
729 // FIXME: If we are generating a shared object we need to copy
730 // this relocation into the object.
731 gold_assert(!parameters
->output_is_shared());
734 case elfcpp::R_X86_64_PC64
:
735 case elfcpp::R_X86_64_PC32
:
736 case elfcpp::R_X86_64_PC16
:
737 case elfcpp::R_X86_64_PC8
:
740 case elfcpp::R_X86_64_GOTPC32
: // TODO(csilvers): correct?
741 case elfcpp::R_X86_64_GOTOFF64
:
742 case elfcpp::R_X86_64_GOTPC64
: // TODO(csilvers): correct?
743 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): correct?
744 // We need a GOT section.
745 target
->got_section(symtab
, layout
);
748 case elfcpp::R_X86_64_GOT64
:
749 case elfcpp::R_X86_64_GOT32
:
750 case elfcpp::R_X86_64_GOTPCREL64
:
751 case elfcpp::R_X86_64_GOTPCREL
:
753 // The symbol requires a GOT entry.
754 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
755 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
756 if (got
->add_local(object
, r_sym
))
758 // If we are generating a shared object, we need to add a
759 // dynamic RELATIVE relocation for this symbol.
760 if (parameters
->output_is_shared())
762 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
763 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
764 data_shndx
, reloc
.get_r_offset(), 0);
770 case elfcpp::R_X86_64_COPY
:
771 case elfcpp::R_X86_64_GLOB_DAT
:
772 case elfcpp::R_X86_64_JUMP_SLOT
:
773 case elfcpp::R_X86_64_RELATIVE
:
774 // These are outstanding tls relocs, which are unexpected when linking
775 case elfcpp::R_X86_64_TPOFF64
:
776 case elfcpp::R_X86_64_DTPMOD64
:
777 case elfcpp::R_X86_64_TLSDESC
:
778 gold_error(_("%s: unexpected reloc %u in object file"),
779 object
->name().c_str(), r_type
);
782 // These are initial tls relocs, which are expected when linking
783 case elfcpp::R_X86_64_TLSGD
:
784 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
785 case elfcpp::R_X86_64_TLSDESC_CALL
:
786 case elfcpp::R_X86_64_TLSLD
:
787 case elfcpp::R_X86_64_GOTTPOFF
:
788 case elfcpp::R_X86_64_TPOFF32
:
789 case elfcpp::R_X86_64_DTPOFF32
:
790 case elfcpp::R_X86_64_DTPOFF64
:
792 bool output_is_shared
= parameters
->output_is_shared();
793 const tls::Tls_optimization optimized_type
794 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
797 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
798 // FIXME: If generating a shared object, we need to copy
799 // this relocation into the object.
800 gold_assert(!output_is_shared
);
803 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
804 // FIXME: If not relaxing to LE, we need to generate a
806 if (optimized_type
!= tls::TLSOPT_TO_LE
)
807 unsupported_reloc_local(object
, r_type
);
810 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
811 case elfcpp::R_X86_64_DTPOFF32
:
812 case elfcpp::R_X86_64_DTPOFF64
:
813 // FIXME: If not relaxing to LE, we need to generate a
815 if (optimized_type
!= tls::TLSOPT_TO_LE
)
816 unsupported_reloc_local(object
, r_type
);
820 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
821 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
822 case elfcpp::R_X86_64_TLSDESC_CALL
:
823 // FIXME: If not relaxing to LE, we need to generate
824 // DTPMOD64 and DTPOFF64 relocs.
825 if (optimized_type
!= tls::TLSOPT_TO_LE
)
826 unsupported_reloc_local(object
, r_type
);
835 case elfcpp::R_X86_64_GOTPLT64
:
836 case elfcpp::R_X86_64_PLT32
:
837 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
838 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
840 gold_error(_("%s: unsupported reloc %u against local symbol"),
841 object
->name().c_str(), r_type
);
847 // Report an unsupported relocation against a global symbol.
850 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
854 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
855 object
->name().c_str(), r_type
, gsym
->name());
858 // Scan a relocation for a global symbol.
861 Target_x86_64::Scan::global(const General_options
& options
,
862 Symbol_table
* symtab
,
864 Target_x86_64
* target
,
865 Sized_relobj
<64, false>* object
,
866 unsigned int data_shndx
,
867 const elfcpp::Rela
<64, false>& reloc
,
873 case elfcpp::R_X86_64_NONE
:
874 case elfcpp::R_386_GNU_VTINHERIT
:
875 case elfcpp::R_386_GNU_VTENTRY
:
878 case elfcpp::R_X86_64_64
:
879 case elfcpp::R_X86_64_PC64
:
880 case elfcpp::R_X86_64_32
:
881 case elfcpp::R_X86_64_32S
:
882 case elfcpp::R_X86_64_PC32
:
883 case elfcpp::R_X86_64_16
:
884 case elfcpp::R_X86_64_PC16
:
885 case elfcpp::R_X86_64_8
:
886 case elfcpp::R_X86_64_PC8
:
887 // FIXME: If we are generating a shared object we may need to
888 // copy this relocation into the object. If this symbol is
889 // defined in a shared object, we may need to copy this
890 // relocation in order to avoid a COPY relocation.
891 gold_assert(!parameters
->output_is_shared());
893 if (gsym
->is_from_dynobj())
895 // This symbol is defined in a dynamic object. If it is a
896 // function, we make a PLT entry. Otherwise we need to
897 // either generate a COPY reloc or copy this reloc.
898 if (gsym
->type() == elfcpp::STT_FUNC
)
900 target
->make_plt_entry(symtab
, layout
, gsym
);
902 // If this is not a PC relative reference, then we may
903 // be taking the address of the function. In that case
904 // we need to set the entry in the dynamic symbol table
905 // to the address of the PLT entry.
906 if (r_type
!= elfcpp::R_X86_64_PC64
907 && r_type
!= elfcpp::R_X86_64_PC32
908 && r_type
!= elfcpp::R_X86_64_PC16
909 && r_type
!= elfcpp::R_X86_64_PC8
)
910 gsym
->set_needs_dynsym_value();
913 target
->copy_reloc(&options
, symtab
, layout
, object
, data_shndx
,
919 case elfcpp::R_X86_64_GOT64
:
920 case elfcpp::R_X86_64_GOT32
:
921 case elfcpp::R_X86_64_GOTPCREL64
:
922 case elfcpp::R_X86_64_GOTPCREL
:
923 case elfcpp::R_X86_64_GOTPLT64
:
925 // The symbol requires a GOT entry.
926 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
927 if (got
->add_global(gsym
))
929 // If this symbol is not fully resolved, we need to add a
930 // dynamic relocation for it.
931 if (!gsym
->final_value_is_known())
933 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
934 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
, got
,
935 gsym
->got_offset(), 0);
941 case elfcpp::R_X86_64_PLT32
:
942 // If the symbol is fully resolved, this is just a PC32 reloc.
943 // Otherwise we need a PLT entry.
944 if (gsym
->final_value_is_known())
946 target
->make_plt_entry(symtab
, layout
, gsym
);
949 case elfcpp::R_X86_64_GOTPC32
: // TODO(csilvers): correct?
950 case elfcpp::R_X86_64_GOTOFF64
:
951 case elfcpp::R_X86_64_GOTPC64
: // TODO(csilvers): correct?
952 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): correct?
953 // We need a GOT section.
954 target
->got_section(symtab
, layout
);
957 case elfcpp::R_X86_64_COPY
:
958 case elfcpp::R_X86_64_GLOB_DAT
:
959 case elfcpp::R_X86_64_JUMP_SLOT
:
960 case elfcpp::R_X86_64_RELATIVE
:
961 // These are outstanding tls relocs, which are unexpected when linking
962 case elfcpp::R_X86_64_TPOFF64
:
963 case elfcpp::R_X86_64_DTPMOD64
:
964 case elfcpp::R_X86_64_TLSDESC
:
965 gold_error(_("%s: unexpected reloc %u in object file"),
966 object
->name().c_str(), r_type
);
969 // These are initial tls relocs, which are expected for global()
970 case elfcpp::R_X86_64_TLSGD
:
971 case elfcpp::R_X86_64_TLSLD
:
972 case elfcpp::R_X86_64_GOTTPOFF
:
973 case elfcpp::R_X86_64_TPOFF32
:
974 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
975 case elfcpp::R_X86_64_TLSDESC_CALL
:
976 case elfcpp::R_X86_64_DTPOFF32
:
977 case elfcpp::R_X86_64_DTPOFF64
:
979 const bool is_final
= gsym
->final_value_is_known();
980 const tls::Tls_optimization optimized_type
981 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
984 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
985 // FIXME: If generating a shared object, we need to copy
986 // this relocation into the object.
987 gold_assert(is_final
);
990 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
991 // FIXME: If not relaxing to LE, we need to generate a
993 if (optimized_type
!= tls::TLSOPT_TO_LE
)
994 unsupported_reloc_global(object
, r_type
, gsym
);
997 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
998 case elfcpp::R_X86_64_DTPOFF32
:
999 case elfcpp::R_X86_64_DTPOFF64
:
1000 // FIXME: If not relaxing to LE, we need to generate a
1002 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1003 unsupported_reloc_global(object
, r_type
, gsym
);
1007 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1008 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1009 case elfcpp::R_X86_64_TLSDESC_CALL
:
1010 // FIXME: If not relaxing to LE, we need to generate
1011 // DTPMOD64 and DTPOFF64, or TLSDESC, relocs.
1012 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1013 unsupported_reloc_global(object
, r_type
, gsym
);
1021 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
1022 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
1024 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1025 object
->name().c_str(), r_type
, gsym
->name());
1030 // Scan relocations for a section.
1033 Target_x86_64::scan_relocs(const General_options
& options
,
1034 Symbol_table
* symtab
,
1036 Sized_relobj
<64, false>* object
,
1037 unsigned int data_shndx
,
1038 unsigned int sh_type
,
1039 const unsigned char* prelocs
,
1041 size_t local_symbol_count
,
1042 const unsigned char* plocal_symbols
,
1043 Symbol
** global_symbols
)
1045 if (sh_type
== elfcpp::SHT_REL
)
1047 gold_error(_("%s: unsupported REL reloc section"),
1048 object
->name().c_str());
1052 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1053 Target_x86_64::Scan
>(
1067 // Finalize the sections.
1070 Target_x86_64::do_finalize_sections(Layout
* layout
)
1072 // Fill in some more dynamic tags.
1073 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1076 if (this->got_plt_
!= NULL
)
1077 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1079 if (this->plt_
!= NULL
)
1081 const Output_data
* od
= this->plt_
->rel_plt();
1082 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1083 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1084 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_RELA
);
1087 if (this->rela_dyn_
!= NULL
)
1089 const Output_data
* od
= this->rela_dyn_
;
1090 odyn
->add_section_address(elfcpp::DT_RELA
, od
);
1091 odyn
->add_section_size(elfcpp::DT_RELASZ
, od
);
1092 odyn
->add_constant(elfcpp::DT_RELAENT
,
1093 elfcpp::Elf_sizes
<64>::rela_size
);
1096 if (!parameters
->output_is_shared())
1098 // The value of the DT_DEBUG tag is filled in by the dynamic
1099 // linker at run time, and used by the debugger.
1100 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1104 // Emit any relocs we saved in an attempt to avoid generating COPY
1106 if (this->copy_relocs_
== NULL
)
1108 if (this->copy_relocs_
->any_to_emit())
1110 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1111 this->copy_relocs_
->emit(rela_dyn
);
1113 delete this->copy_relocs_
;
1114 this->copy_relocs_
= NULL
;
1117 // Perform a relocation.
1120 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1121 Target_x86_64
* target
,
1123 const elfcpp::Rela
<64, false>& rela
,
1124 unsigned int r_type
,
1125 const Sized_symbol
<64>* gsym
,
1126 const Symbol_value
<64>* psymval
,
1127 unsigned char* view
,
1128 elfcpp::Elf_types
<64>::Elf_Addr address
,
1131 if (this->skip_call_tls_get_addr_
)
1133 if (r_type
!= elfcpp::R_X86_64_PLT32
1135 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1137 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1138 _("missing expected TLS relocation"));
1142 this->skip_call_tls_get_addr_
= false;
1147 // Pick the value to use for symbols defined in shared objects.
1148 Symbol_value
<64> symval
;
1149 if (gsym
!= NULL
&& gsym
->is_from_dynobj() && gsym
->has_plt_offset())
1151 symval
.set_output_value(target
->plt_section()->address()
1152 + gsym
->plt_offset());
1156 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1157 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1159 // Get the GOT offset if needed.
1160 bool have_got_offset
= false;
1161 unsigned int got_offset
= 0;
1164 case elfcpp::R_X86_64_GOT32
:
1165 case elfcpp::R_X86_64_GOT64
:
1166 case elfcpp::R_X86_64_GOTPLT64
:
1167 case elfcpp::R_X86_64_GOTPCREL
:
1168 case elfcpp::R_X86_64_GOTPCREL64
:
1171 gold_assert(gsym
->has_got_offset());
1172 got_offset
= gsym
->got_offset();
1176 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1177 got_offset
= object
->local_got_offset(r_sym
);
1179 have_got_offset
= true;
1189 case elfcpp::R_X86_64_NONE
:
1190 case elfcpp::R_386_GNU_VTINHERIT
:
1191 case elfcpp::R_386_GNU_VTENTRY
:
1194 case elfcpp::R_X86_64_64
:
1195 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1198 case elfcpp::R_X86_64_PC64
:
1199 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1203 case elfcpp::R_X86_64_32
:
1204 // FIXME: we need to verify that value + addend fits into 32 bits:
1205 // uint64_t x = value + addend;
1206 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1207 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1208 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1211 case elfcpp::R_X86_64_32S
:
1212 // FIXME: we need to verify that value + addend fits into 32 bits:
1213 // int64_t x = value + addend; // note this quantity is signed!
1214 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1215 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1218 case elfcpp::R_X86_64_PC32
:
1219 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1223 case elfcpp::R_X86_64_16
:
1224 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
1227 case elfcpp::R_X86_64_PC16
:
1228 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
1232 case elfcpp::R_X86_64_8
:
1233 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
1236 case elfcpp::R_X86_64_PC8
:
1237 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
1241 case elfcpp::R_X86_64_PLT32
:
1242 gold_assert(gsym
->has_plt_offset()
1243 || gsym
->final_value_is_known());
1244 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1248 case elfcpp::R_X86_64_GOT32
:
1249 gold_assert(have_got_offset
);
1250 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
1253 case elfcpp::R_X86_64_GOTPC32
:
1256 elfcpp::Elf_types
<64>::Elf_Addr value
;
1257 value
= target
->got_section(NULL
, NULL
)->address();
1258 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1262 case elfcpp::R_X86_64_GOT64
:
1263 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1264 // Since we always add a PLT entry, this is equivalent.
1265 case elfcpp::R_X86_64_GOTPLT64
: // TODO(csilvers): correct?
1266 gold_assert(have_got_offset
);
1267 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
1270 case elfcpp::R_X86_64_GOTPC64
:
1273 elfcpp::Elf_types
<64>::Elf_Addr value
;
1274 value
= target
->got_section(NULL
, NULL
)->address();
1275 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1279 case elfcpp::R_X86_64_GOTOFF64
:
1281 elfcpp::Elf_types
<64>::Elf_Addr value
;
1282 value
= (psymval
->value(object
, 0)
1283 - target
->got_section(NULL
, NULL
)->address());
1284 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
1288 case elfcpp::R_X86_64_GOTPCREL
:
1290 gold_assert(have_got_offset
);
1291 elfcpp::Elf_types
<64>::Elf_Addr value
;
1292 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1293 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1297 case elfcpp::R_X86_64_GOTPCREL64
:
1299 gold_assert(have_got_offset
);
1300 elfcpp::Elf_types
<64>::Elf_Addr value
;
1301 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1302 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1306 case elfcpp::R_X86_64_COPY
:
1307 case elfcpp::R_X86_64_GLOB_DAT
:
1308 case elfcpp::R_X86_64_JUMP_SLOT
:
1309 case elfcpp::R_X86_64_RELATIVE
:
1310 // These are outstanding tls relocs, which are unexpected when linking
1311 case elfcpp::R_X86_64_TPOFF64
:
1312 case elfcpp::R_X86_64_DTPMOD64
:
1313 case elfcpp::R_X86_64_TLSDESC
:
1314 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1315 _("unexpected reloc %u in object file"),
1319 // These are initial tls relocs, which are expected when linking
1320 case elfcpp::R_X86_64_TLSGD
:
1321 case elfcpp::R_X86_64_TLSLD
:
1322 case elfcpp::R_X86_64_GOTTPOFF
:
1323 case elfcpp::R_X86_64_TPOFF32
:
1324 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1325 case elfcpp::R_X86_64_TLSDESC_CALL
:
1326 case elfcpp::R_X86_64_DTPOFF32
:
1327 case elfcpp::R_X86_64_DTPOFF64
:
1328 this->relocate_tls(relinfo
, relnum
, rela
, r_type
, gsym
, psymval
, view
,
1329 address
, view_size
);
1332 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
1333 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
1334 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): implement me!
1336 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1337 _("unsupported reloc %u"),
1345 // Perform a TLS relocation.
1348 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
1350 const elfcpp::Rela
<64, false>& rel
,
1351 unsigned int r_type
,
1352 const Sized_symbol
<64>* gsym
,
1353 const Symbol_value
<64>* psymval
,
1354 unsigned char* view
,
1355 elfcpp::Elf_types
<64>::Elf_Addr
,
1358 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1359 if (tls_segment
== NULL
)
1361 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1362 _("TLS reloc but no TLS segment"));
1366 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1368 const bool is_final
= (gsym
== NULL
1369 ? !parameters
->output_is_shared()
1370 : gsym
->final_value_is_known());
1371 const tls::Tls_optimization optimized_type
1372 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1375 case elfcpp::R_X86_64_TPOFF32
: // Local-exec reloc
1376 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1377 Relocate_functions
<64, false>::rel32(view
, value
);
1380 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec reloc
1381 if (optimized_type
== tls::TLSOPT_TO_LE
)
1383 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1384 rel
, r_type
, value
, view
,
1388 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1389 _("unsupported reloc type %u"),
1393 case elfcpp::R_X86_64_TLSGD
:
1394 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1395 case elfcpp::R_X86_64_TLSDESC_CALL
:
1396 if (optimized_type
== tls::TLSOPT_TO_LE
)
1398 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1399 rel
, r_type
, value
, view
,
1403 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1404 _("unsupported reloc %u"), r_type
);
1407 case elfcpp::R_X86_64_TLSLD
:
1408 if (optimized_type
== tls::TLSOPT_TO_LE
)
1410 // FIXME: implement ld_to_le
1412 gold_error_at_location(relinfo
, relnum
, rel
.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>& rel
,
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 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -3);
1454 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, 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>& rel
,
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 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -4);
1508 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 12);
1510 Target_x86_64::Relocate::check_tls(relinfo
, relnum
, rel
,
1511 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4)
1513 Target_x86_64::Relocate::check_tls(relinfo
, relnum
, rel
,
1514 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4)
1517 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
1519 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1520 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
1522 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1524 this->skip_call_tls_get_addr_
= true;
1527 // Check the range for a TLS relocation.
1530 Target_x86_64::Relocate::check_range(const Relocate_info
<64, false>* relinfo
,
1532 const elfcpp::Rela
<64, false>& rel
,
1533 off_t view_size
, off_t off
)
1535 off_t offset
= rel
.get_r_offset() + off
;
1536 if (offset
< 0 || offset
> view_size
)
1537 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1538 _("TLS relocation out of range"));
1541 // Check the validity of a TLS relocation. This is like assert.
1544 Target_x86_64::Relocate::check_tls(const Relocate_info
<64, false>* relinfo
,
1546 const elfcpp::Rela
<64, false>& rel
,
1550 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
1551 _("TLS relocation against invalid instruction"));
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.