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 fprintf(stderr
, _("%s: missing expected TLS relocation\n"),
160 // Do a relocation. Return false if the caller should not issue
161 // any warnings about this relocation.
163 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, size_t relnum
,
164 const elfcpp::Rela
<64, false>&,
165 unsigned int r_type
, const Sized_symbol
<64>*,
166 const Symbol_value
<64>*,
167 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
171 // Do a TLS relocation.
173 relocate_tls(const Relocate_info
<64, false>*, size_t relnum
,
174 const elfcpp::Rela
<64, false>&,
175 unsigned int r_type
, const Sized_symbol
<64>*,
176 const Symbol_value
<64>*,
177 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
, off_t
);
179 // Do a TLS Initial-Exec to Local-Exec transition.
181 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
182 Output_segment
* tls_segment
,
183 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
184 elfcpp::Elf_types
<64>::Elf_Addr value
,
188 // Do a TLS General-Dynamic to Local-Exec transition.
190 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
191 Output_segment
* tls_segment
,
192 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
193 elfcpp::Elf_types
<64>::Elf_Addr value
,
197 // Check the range for a TLS relocation.
199 check_range(const Relocate_info
<64, false>*, size_t relnum
,
200 const elfcpp::Rela
<64, false>&, off_t
, off_t
);
202 // Check the validity of a TLS relocation. This is like assert.
204 check_tls(const Relocate_info
<64, false>*, size_t relnum
,
205 const elfcpp::Rela
<64, false>&, bool);
207 // This is set if we should skip the next reloc, which should be a
208 // PLT32 reloc against ___tls_get_addr.
209 bool skip_call_tls_get_addr_
;
212 // Adjust TLS relocation type based on the options and whether this
213 // is a local symbol.
214 static tls::Tls_optimization
215 optimize_tls_reloc(bool is_final
, int r_type
);
217 // Get the GOT section, creating it if necessary.
218 Output_data_got
<64, false>*
219 got_section(Symbol_table
*, Layout
*);
221 // Create a PLT entry for a global symbol.
223 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
225 // Get the PLT section.
226 Output_data_plt_x86_64
*
229 gold_assert(this->plt_
!= NULL
);
233 // Get the dynamic reloc section, creating it if necessary.
235 rela_dyn_section(Layout
*);
237 // Copy a relocation against a global symbol.
239 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
240 Sized_relobj
<64, false>*, unsigned int,
241 Symbol
*, const elfcpp::Rela
<64, false>&);
243 // Information about this specific target which we pass to the
244 // general Target structure.
245 static const Target::Target_info x86_64_info
;
248 Output_data_got
<64, false>* got_
;
250 Output_data_plt_x86_64
* plt_
;
251 // The GOT PLT section.
252 Output_data_space
* got_plt_
;
253 // The dynamic reloc section.
254 Reloc_section
* rela_dyn_
;
255 // Relocs saved to avoid a COPY reloc.
256 Copy_relocs
<64, false>* copy_relocs_
;
257 // Space for variables copied with a COPY reloc.
258 Output_data_space
* dynbss_
;
261 const Target::Target_info
Target_x86_64::x86_64_info
=
264 false, // is_big_endian
265 elfcpp::EM_X86_64
, // machine_code
266 false, // has_make_symbol
267 false, // has_resolve
268 true, // has_code_fill
269 "/lib/ld64.so.1", // program interpreter
270 0x400000, // text_segment_address
271 0x1000, // abi_pagesize
272 0x1000 // common_pagesize
275 // Get the GOT section, creating it if necessary.
277 Output_data_got
<64, false>*
278 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
280 if (this->got_
== NULL
)
282 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
284 this->got_
= new Output_data_got
<64, false>();
286 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
287 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
290 // The old GNU linker creates a .got.plt section. We just
291 // create another set of data in the .got section. Note that we
292 // always create a PLT if we create a GOT, although the PLT
294 // TODO(csilvers): do we really need an alignment of 8?
295 this->got_plt_
= new Output_data_space(8);
296 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
297 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
300 // The first three entries are reserved.
301 this->got_plt_
->set_space_size(3 * 8);
303 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
304 symtab
->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL
,
306 0, 0, elfcpp::STT_OBJECT
,
308 elfcpp::STV_HIDDEN
, 0,
315 // Get the dynamic reloc section, creating it if necessary.
317 Target_x86_64::Reloc_section
*
318 Target_x86_64::rela_dyn_section(Layout
* layout
)
320 if (this->rela_dyn_
== NULL
)
322 gold_assert(layout
!= NULL
);
323 this->rela_dyn_
= new Reloc_section();
324 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
325 elfcpp::SHF_ALLOC
, this->rela_dyn_
);
327 return this->rela_dyn_
;
330 // A class to handle the PLT data.
332 class Output_data_plt_x86_64
: public Output_section_data
335 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
337 Output_data_plt_x86_64(Layout
*, Output_data_space
*);
339 // Add an entry to the PLT.
341 add_entry(Symbol
* gsym
);
343 // Return the .rel.plt section data.
346 { return this->rel_
; }
350 do_adjust_output_section(Output_section
* os
);
353 // The size of an entry in the PLT.
354 static const int plt_entry_size
= 16;
356 // The first entry in the PLT.
357 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
358 // procedure linkage table for both programs and shared objects."
359 static unsigned char first_plt_entry
[plt_entry_size
];
361 // Other entries in the PLT for an executable.
362 static unsigned char plt_entry
[plt_entry_size
];
364 // Set the final size.
366 do_set_address(uint64_t, off_t
)
367 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
369 // Write out the PLT data.
371 do_write(Output_file
*);
373 // The reloc section.
375 // The .got.plt section.
376 Output_data_space
* got_plt_
;
377 // The number of PLT entries.
381 // Create the PLT section. The ordinary .got section is an argument,
382 // since we need to refer to the start. We also create our own .got
383 // section just for PLT entries.
385 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout
* layout
,
386 Output_data_space
* got_plt
)
387 // TODO(csilvers): do we really need an alignment of 8?
388 : Output_section_data(8), got_plt_(got_plt
), count_(0)
390 this->rel_
= new Reloc_section();
391 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
392 elfcpp::SHF_ALLOC
, this->rel_
);
396 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
398 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
399 // linker, and so do we.
403 // Add an entry to the PLT.
406 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
408 gold_assert(!gsym
->has_plt_offset());
410 // Note that when setting the PLT offset we skip the initial
411 // reserved PLT entry.
412 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
416 off_t got_offset
= this->got_plt_
->data_size();
418 // Every PLT entry needs a GOT entry which points back to the PLT
419 // entry (this will be changed by the dynamic linker, normally
420 // lazily when the function is called).
421 this->got_plt_
->set_space_size(got_offset
+ 8);
423 // Every PLT entry needs a reloc.
424 gsym
->set_needs_dynsym_entry();
425 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
428 // Note that we don't need to save the symbol. The contents of the
429 // PLT are independent of which symbols are used. The symbols only
430 // appear in the relocations.
433 // The first entry in the PLT for an executable.
435 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
437 // From AMD64 ABI Draft 0.98, page 76
438 0xff, 0x35, // pushq contents of memory address
439 0, 0, 0, 0, // replaced with address of .got + 4
440 0xff, 0x25, // jmp indirect
441 0, 0, 0, 0, // replaced with address of .got + 8
442 0x90, 0x90, 0x90, 0x90 // noop (x4)
445 // Subsequent entries in the PLT for an executable.
447 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
449 // From AMD64 ABI Draft 0.98, page 76
450 0xff, 0x25, // jmpq indirect
451 0, 0, 0, 0, // replaced with address of symbol in .got
452 0x68, // pushq immediate
453 0, 0, 0, 0, // replaced with offset into relocation table
454 0xe9, // jmpq relative
455 0, 0, 0, 0 // replaced with offset to start of .plt
458 // Write out the PLT. This uses the hand-coded instructions above,
459 // and adjusts them as needed. This is specified by the AMD64 ABI.
462 Output_data_plt_x86_64::do_write(Output_file
* of
)
464 const off_t offset
= this->offset();
465 const off_t oview_size
= this->data_size();
466 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
468 const off_t got_file_offset
= this->got_plt_
->offset();
469 const off_t got_size
= this->got_plt_
->data_size();
470 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
473 unsigned char* pov
= oview
;
475 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
476 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
478 memcpy(pov
, first_plt_entry
, plt_entry_size
);
479 if (!parameters
->output_is_shared())
481 // We do a jmp relative to the PC at the end of this instruction.
482 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 8
483 - (plt_address
+ 6));
484 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 16
485 - (plt_address
+ 12));
487 pov
+= plt_entry_size
;
489 unsigned char* got_pov
= got_view
;
491 memset(got_pov
, 0, 24);
494 unsigned int plt_offset
= plt_entry_size
;
495 unsigned int got_offset
= 24;
496 const unsigned int count
= this->count_
;
497 for (unsigned int plt_index
= 0;
500 pov
+= plt_entry_size
,
502 plt_offset
+= plt_entry_size
,
505 // Set and adjust the PLT entry itself.
506 memcpy(pov
, plt_entry
, plt_entry_size
);
507 if (parameters
->output_is_shared())
508 // FIXME(csilvers): what's the right thing to write here?
509 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
511 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
512 (got_address
+ got_offset
513 - (plt_address
+ plt_offset
516 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
517 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
518 - (plt_offset
+ plt_entry_size
));
520 // Set the entry in the GOT.
521 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
524 gold_assert(pov
- oview
== oview_size
);
525 gold_assert(got_pov
- got_view
== got_size
);
527 of
->write_output_view(offset
, oview_size
, oview
);
528 of
->write_output_view(got_file_offset
, got_size
, got_view
);
531 // Create a PLT entry for a global symbol.
534 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
537 if (gsym
->has_plt_offset())
540 if (this->plt_
== NULL
)
542 // Create the GOT sections first.
543 this->got_section(symtab
, layout
);
545 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_plt_
);
546 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
548 | elfcpp::SHF_EXECINSTR
),
552 this->plt_
->add_entry(gsym
);
555 // Handle a relocation against a non-function symbol defined in a
556 // dynamic object. The traditional way to handle this is to generate
557 // a COPY relocation to copy the variable at runtime from the shared
558 // object into the executable's data segment. However, this is
559 // undesirable in general, as if the size of the object changes in the
560 // dynamic object, the executable will no longer work correctly. If
561 // this relocation is in a writable section, then we can create a
562 // dynamic reloc and the dynamic linker will resolve it to the correct
563 // address at runtime. However, we do not want do that if the
564 // relocation is in a read-only section, as it would prevent the
565 // readonly segment from being shared. And if we have to eventually
566 // generate a COPY reloc, then any dynamic relocations will be
567 // useless. So this means that if this is a writable section, we need
568 // to save the relocation until we see whether we have to create a
569 // COPY relocation for this symbol for any other relocation.
572 Target_x86_64::copy_reloc(const General_options
* options
,
573 Symbol_table
* symtab
,
575 Sized_relobj
<64, false>* object
,
576 unsigned int data_shndx
, Symbol
* gsym
,
577 const elfcpp::Rela
<64, false>& rel
)
579 Sized_symbol
<64>* ssym
;
580 ssym
= symtab
->get_sized_symbol
SELECT_SIZE_NAME(64) (gsym
583 if (!Copy_relocs
<64, false>::need_copy_reloc(options
, object
,
586 // So far we do not need a COPY reloc. Save this relocation.
587 // If it turns out that we never need a COPY reloc for this
588 // symbol, then we will emit the relocation.
589 if (this->copy_relocs_
== NULL
)
590 this->copy_relocs_
= new Copy_relocs
<64, false>();
591 this->copy_relocs_
->save(ssym
, object
, data_shndx
, rel
);
595 // Allocate space for this symbol in the .bss section.
597 elfcpp::Elf_types
<64>::Elf_WXword symsize
= ssym
->symsize();
599 // There is no defined way to determine the required alignment
600 // of the symbol. We pick the alignment based on the size. We
601 // set an arbitrary maximum of 256.
603 for (align
= 1; align
< 512; align
<<= 1)
604 if ((symsize
& align
) != 0)
607 if (this->dynbss_
== NULL
)
609 this->dynbss_
= new Output_data_space(align
);
610 layout
->add_output_section_data(".bss",
613 | elfcpp::SHF_WRITE
),
617 Output_data_space
* dynbss
= this->dynbss_
;
619 if (align
> dynbss
->addralign())
620 dynbss
->set_space_alignment(align
);
622 off_t dynbss_size
= dynbss
->data_size();
623 dynbss_size
= align_address(dynbss_size
, align
);
624 off_t offset
= dynbss_size
;
625 dynbss
->set_space_size(dynbss_size
+ symsize
);
627 // Define the symbol in the .dynbss section.
628 symtab
->define_in_output_data(this, ssym
->name(), ssym
->version(),
629 dynbss
, offset
, symsize
, ssym
->type(),
630 ssym
->binding(), ssym
->visibility(),
631 ssym
->nonvis(), false, false);
633 // Add the COPY reloc.
634 ssym
->set_needs_dynsym_entry();
635 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
636 rela_dyn
->add_global(ssym
, elfcpp::R_X86_64_COPY
, dynbss
, offset
, 0);
641 // Optimize the TLS relocation type based on what we know about the
642 // symbol. IS_FINAL is true if the final address of this symbol is
643 // known at link time.
645 tls::Tls_optimization
646 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
648 // If we are generating a shared library, then we can't do anything
650 if (parameters
->output_is_shared())
651 return tls::TLSOPT_NONE
;
655 case elfcpp::R_X86_64_TLSGD
:
656 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
657 case elfcpp::R_X86_64_TLSDESC_CALL
:
658 // These are General-Dynamic which permits fully general TLS
659 // access. Since we know that we are generating an executable,
660 // we can convert this to Initial-Exec. If we also know that
661 // this is a local symbol, we can further switch to Local-Exec.
663 return tls::TLSOPT_TO_LE
;
664 return tls::TLSOPT_TO_IE
;
666 case elfcpp::R_X86_64_TLSLD
:
667 // This is Local-Dynamic, which refers to a local symbol in the
668 // dynamic TLS block. Since we know that we generating an
669 // executable, we can switch to Local-Exec.
670 return tls::TLSOPT_TO_LE
;
672 case elfcpp::R_X86_64_DTPOFF32
:
673 case elfcpp::R_X86_64_DTPOFF64
:
674 // Another Local-Dynamic reloc.
675 return tls::TLSOPT_TO_LE
;
677 case elfcpp::R_X86_64_GOTTPOFF
:
678 // These are Initial-Exec relocs which get the thread offset
679 // from the GOT. If we know that we are linking against the
680 // local symbol, we can switch to Local-Exec, which links the
681 // thread offset into the instruction.
683 return tls::TLSOPT_TO_LE
;
684 return tls::TLSOPT_NONE
;
686 case elfcpp::R_X86_64_TPOFF32
:
687 // When we already have Local-Exec, there is nothing further we
689 return tls::TLSOPT_NONE
;
696 // Report an unsupported relocation against a local symbol.
699 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
702 fprintf(stderr
, _("%s: %s: unsupported reloc %u against local symbol\n"),
703 program_name
, object
->name().c_str(), r_type
);
706 // Scan a relocation for a local symbol.
709 Target_x86_64::Scan::local(const General_options
&,
710 Symbol_table
* symtab
,
712 Target_x86_64
* target
,
713 Sized_relobj
<64, false>* object
,
714 unsigned int data_shndx
,
715 const elfcpp::Rela
<64, false>& reloc
,
717 const elfcpp::Sym
<64, false>&)
721 case elfcpp::R_X86_64_NONE
:
722 case elfcpp::R_386_GNU_VTINHERIT
:
723 case elfcpp::R_386_GNU_VTENTRY
:
726 case elfcpp::R_X86_64_64
:
727 case elfcpp::R_X86_64_32
:
728 case elfcpp::R_X86_64_32S
:
729 case elfcpp::R_X86_64_16
:
730 case elfcpp::R_X86_64_8
:
731 // FIXME: If we are generating a shared object we need to copy
732 // this relocation into the object.
733 gold_assert(!parameters
->output_is_shared());
736 case elfcpp::R_X86_64_PC64
:
737 case elfcpp::R_X86_64_PC32
:
738 case elfcpp::R_X86_64_PC16
:
739 case elfcpp::R_X86_64_PC8
:
742 case elfcpp::R_X86_64_GOTPC32
: // TODO(csilvers): correct?
743 case elfcpp::R_X86_64_GOTOFF64
:
744 case elfcpp::R_X86_64_GOTPC64
: // TODO(csilvers): correct?
745 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): correct?
746 // We need a GOT section.
747 target
->got_section(symtab
, layout
);
750 case elfcpp::R_X86_64_GOT64
:
751 case elfcpp::R_X86_64_GOT32
:
752 case elfcpp::R_X86_64_GOTPCREL64
:
753 case elfcpp::R_X86_64_GOTPCREL
:
755 // The symbol requires a GOT entry.
756 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
757 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
758 if (got
->add_local(object
, r_sym
))
760 // If we are generating a shared object, we need to add a
761 // dynamic RELATIVE relocation for this symbol.
762 if (parameters
->output_is_shared())
764 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
765 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
766 data_shndx
, reloc
.get_r_offset(), 0);
772 case elfcpp::R_X86_64_COPY
:
773 case elfcpp::R_X86_64_GLOB_DAT
:
774 case elfcpp::R_X86_64_JUMP_SLOT
:
775 case elfcpp::R_X86_64_RELATIVE
:
776 // These are outstanding tls relocs, which are unexpected when linking
777 case elfcpp::R_X86_64_TPOFF64
:
778 case elfcpp::R_X86_64_DTPMOD64
:
779 case elfcpp::R_X86_64_TLSDESC
:
780 fprintf(stderr
, _("%s: %s: unexpected reloc %u in object file\n"),
781 program_name
, object
->name().c_str(), r_type
);
785 // These are initial tls relocs, which are expected when linking
786 case elfcpp::R_X86_64_TLSGD
:
787 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
788 case elfcpp::R_X86_64_TLSDESC_CALL
:
789 case elfcpp::R_X86_64_TLSLD
:
790 case elfcpp::R_X86_64_GOTTPOFF
:
791 case elfcpp::R_X86_64_TPOFF32
:
792 case elfcpp::R_X86_64_DTPOFF32
:
793 case elfcpp::R_X86_64_DTPOFF64
:
795 bool output_is_shared
= parameters
->output_is_shared();
796 const tls::Tls_optimization optimized_type
797 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
800 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
801 // FIXME: If generating a shared object, we need to copy
802 // this relocation into the object.
803 gold_assert(!output_is_shared
);
806 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
807 // FIXME: If not relaxing to LE, we need to generate a
809 if (optimized_type
!= tls::TLSOPT_TO_LE
)
810 unsupported_reloc_local(object
, r_type
);
813 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
814 case elfcpp::R_X86_64_DTPOFF32
:
815 case elfcpp::R_X86_64_DTPOFF64
:
816 // FIXME: If not relaxing to LE, we need to generate a
818 if (optimized_type
!= tls::TLSOPT_TO_LE
)
819 unsupported_reloc_local(object
, r_type
);
823 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
824 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
825 case elfcpp::R_X86_64_TLSDESC_CALL
:
826 // FIXME: If not relaxing to LE, we need to generate
827 // DTPMOD64 and DTPOFF64 relocs.
828 if (optimized_type
!= tls::TLSOPT_TO_LE
)
829 unsupported_reloc_local(object
, r_type
);
838 case elfcpp::R_X86_64_GOTPLT64
:
839 case elfcpp::R_X86_64_PLT32
:
840 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
841 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
843 fprintf(stderr
, _("%s: %s: unsupported reloc %u against local symbol\n"),
844 program_name
, object
->name().c_str(), r_type
);
850 // Report an unsupported relocation against a global symbol.
853 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
858 _("%s: %s: unsupported reloc %u against global symbol %s\n"),
859 program_name
, object
->name().c_str(), r_type
, gsym
->name());
862 // Scan a relocation for a global symbol.
865 Target_x86_64::Scan::global(const General_options
& options
,
866 Symbol_table
* symtab
,
868 Target_x86_64
* target
,
869 Sized_relobj
<64, false>* object
,
870 unsigned int data_shndx
,
871 const elfcpp::Rela
<64, false>& reloc
,
877 case elfcpp::R_X86_64_NONE
:
878 case elfcpp::R_386_GNU_VTINHERIT
:
879 case elfcpp::R_386_GNU_VTENTRY
:
882 case elfcpp::R_X86_64_64
:
883 case elfcpp::R_X86_64_PC64
:
884 case elfcpp::R_X86_64_32
:
885 case elfcpp::R_X86_64_32S
:
886 case elfcpp::R_X86_64_PC32
:
887 case elfcpp::R_X86_64_16
:
888 case elfcpp::R_X86_64_PC16
:
889 case elfcpp::R_X86_64_8
:
890 case elfcpp::R_X86_64_PC8
:
891 // FIXME: If we are generating a shared object we may need to
892 // copy this relocation into the object. If this symbol is
893 // defined in a shared object, we may need to copy this
894 // relocation in order to avoid a COPY relocation.
895 gold_assert(!parameters
->output_is_shared());
897 if (gsym
->is_from_dynobj())
899 // This symbol is defined in a dynamic object. If it is a
900 // function, we make a PLT entry. Otherwise we need to
901 // either generate a COPY reloc or copy this reloc.
902 if (gsym
->type() == elfcpp::STT_FUNC
)
904 target
->make_plt_entry(symtab
, layout
, gsym
);
906 // If this is not a PC relative reference, then we may
907 // be taking the address of the function. In that case
908 // we need to set the entry in the dynamic symbol table
909 // to the address of the PLT entry.
910 if (r_type
!= elfcpp::R_X86_64_PC64
911 && r_type
!= elfcpp::R_X86_64_PC32
912 && r_type
!= elfcpp::R_X86_64_PC16
913 && r_type
!= elfcpp::R_X86_64_PC8
)
914 gsym
->set_needs_dynsym_value();
917 target
->copy_reloc(&options
, symtab
, layout
, object
, data_shndx
,
923 case elfcpp::R_X86_64_GOT64
:
924 case elfcpp::R_X86_64_GOT32
:
925 case elfcpp::R_X86_64_GOTPCREL64
:
926 case elfcpp::R_X86_64_GOTPCREL
:
927 case elfcpp::R_X86_64_GOTPLT64
:
929 // The symbol requires a GOT entry.
930 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
931 if (got
->add_global(gsym
))
933 // If this symbol is not fully resolved, we need to add a
934 // dynamic relocation for it.
935 if (!gsym
->final_value_is_known())
937 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
938 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
, got
,
939 gsym
->got_offset(), 0);
945 case elfcpp::R_X86_64_PLT32
:
946 // If the symbol is fully resolved, this is just a PC32 reloc.
947 // Otherwise we need a PLT entry.
948 if (gsym
->final_value_is_known())
950 target
->make_plt_entry(symtab
, layout
, gsym
);
953 case elfcpp::R_X86_64_GOTPC32
: // TODO(csilvers): correct?
954 case elfcpp::R_X86_64_GOTOFF64
:
955 case elfcpp::R_X86_64_GOTPC64
: // TODO(csilvers): correct?
956 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): correct?
957 // We need a GOT section.
958 target
->got_section(symtab
, layout
);
961 case elfcpp::R_X86_64_COPY
:
962 case elfcpp::R_X86_64_GLOB_DAT
:
963 case elfcpp::R_X86_64_JUMP_SLOT
:
964 case elfcpp::R_X86_64_RELATIVE
:
965 // These are outstanding tls relocs, which are unexpected when linking
966 case elfcpp::R_X86_64_TPOFF64
:
967 case elfcpp::R_X86_64_DTPMOD64
:
968 case elfcpp::R_X86_64_TLSDESC
:
969 fprintf(stderr
, _("%s: %s: unexpected reloc %u in object file\n"),
970 program_name
, object
->name().c_str(), r_type
);
974 // These are initial tls relocs, which are expected for global()
975 case elfcpp::R_X86_64_TLSGD
:
976 case elfcpp::R_X86_64_TLSLD
:
977 case elfcpp::R_X86_64_GOTTPOFF
:
978 case elfcpp::R_X86_64_TPOFF32
:
979 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
980 case elfcpp::R_X86_64_TLSDESC_CALL
:
981 case elfcpp::R_X86_64_DTPOFF32
:
982 case elfcpp::R_X86_64_DTPOFF64
:
984 const bool is_final
= gsym
->final_value_is_known();
985 const tls::Tls_optimization optimized_type
986 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
989 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
990 // FIXME: If generating a shared object, we need to copy
991 // this relocation into the object.
992 gold_assert(is_final
);
995 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
996 // FIXME: If not relaxing to LE, we need to generate a
998 if (optimized_type
!= tls::TLSOPT_TO_LE
)
999 unsupported_reloc_global(object
, r_type
, gsym
);
1002 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1003 case elfcpp::R_X86_64_DTPOFF32
:
1004 case elfcpp::R_X86_64_DTPOFF64
:
1005 // FIXME: If not relaxing to LE, we need to generate a
1007 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1008 unsupported_reloc_global(object
, r_type
, gsym
);
1012 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1013 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1014 case elfcpp::R_X86_64_TLSDESC_CALL
:
1015 // FIXME: If not relaxing to LE, we need to generate
1016 // DTPMOD64 and DTPOFF64, or TLSDESC, relocs.
1017 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1018 unsupported_reloc_global(object
, r_type
, gsym
);
1026 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
1027 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
1030 _("%s: %s: unsupported reloc %u against global symbol %s\n"),
1031 program_name
, object
->name().c_str(), r_type
, gsym
->name());
1036 // Scan relocations for a section.
1039 Target_x86_64::scan_relocs(const General_options
& options
,
1040 Symbol_table
* symtab
,
1042 Sized_relobj
<64, false>* object
,
1043 unsigned int data_shndx
,
1044 unsigned int sh_type
,
1045 const unsigned char* prelocs
,
1047 size_t local_symbol_count
,
1048 const unsigned char* plocal_symbols
,
1049 Symbol
** global_symbols
)
1051 if (sh_type
== elfcpp::SHT_REL
)
1053 fprintf(stderr
, _("%s: %s: unsupported REL reloc section\n"),
1054 program_name
, object
->name().c_str());
1058 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1059 Target_x86_64::Scan
>(
1073 // Finalize the sections.
1076 Target_x86_64::do_finalize_sections(Layout
* layout
)
1078 // Fill in some more dynamic tags.
1079 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1082 if (this->got_plt_
!= NULL
)
1083 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1085 if (this->plt_
!= NULL
)
1087 const Output_data
* od
= this->plt_
->rel_plt();
1088 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1089 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1090 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_RELA
);
1093 if (this->rela_dyn_
!= NULL
)
1095 const Output_data
* od
= this->rela_dyn_
;
1096 odyn
->add_section_address(elfcpp::DT_RELA
, od
);
1097 odyn
->add_section_size(elfcpp::DT_RELASZ
, od
);
1098 odyn
->add_constant(elfcpp::DT_RELAENT
,
1099 elfcpp::Elf_sizes
<64>::rela_size
);
1102 if (!parameters
->output_is_shared())
1104 // The value of the DT_DEBUG tag is filled in by the dynamic
1105 // linker at run time, and used by the debugger.
1106 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1110 // Emit any relocs we saved in an attempt to avoid generating COPY
1112 if (this->copy_relocs_
== NULL
)
1114 if (this->copy_relocs_
->any_to_emit())
1116 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1117 this->copy_relocs_
->emit(rela_dyn
);
1119 delete this->copy_relocs_
;
1120 this->copy_relocs_
= NULL
;
1123 // Perform a relocation.
1126 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1127 Target_x86_64
* target
,
1129 const elfcpp::Rela
<64, false>& rela
,
1130 unsigned int r_type
,
1131 const Sized_symbol
<64>* gsym
,
1132 const Symbol_value
<64>* psymval
,
1133 unsigned char* view
,
1134 elfcpp::Elf_types
<64>::Elf_Addr address
,
1137 if (this->skip_call_tls_get_addr_
)
1139 if (r_type
!= elfcpp::R_X86_64_PLT32
1141 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1143 fprintf(stderr
, _("%s: %s: missing expected TLS relocation\n"),
1145 relinfo
->location(relnum
, rela
.get_r_offset()).c_str());
1149 this->skip_call_tls_get_addr_
= false;
1154 // Pick the value to use for symbols defined in shared objects.
1155 Symbol_value
<64> symval
;
1156 if (gsym
!= NULL
&& gsym
->is_from_dynobj() && gsym
->has_plt_offset())
1158 symval
.set_output_value(target
->plt_section()->address()
1159 + gsym
->plt_offset());
1163 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1164 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1166 // Get the GOT offset if needed.
1167 bool have_got_offset
= false;
1168 unsigned int got_offset
= 0;
1171 case elfcpp::R_X86_64_GOT32
:
1172 case elfcpp::R_X86_64_GOT64
:
1173 case elfcpp::R_X86_64_GOTPLT64
:
1174 case elfcpp::R_X86_64_GOTPCREL
:
1175 case elfcpp::R_X86_64_GOTPCREL64
:
1178 gold_assert(gsym
->has_got_offset());
1179 got_offset
= gsym
->got_offset();
1183 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1184 got_offset
= object
->local_got_offset(r_sym
);
1186 have_got_offset
= true;
1196 case elfcpp::R_X86_64_NONE
:
1197 case elfcpp::R_386_GNU_VTINHERIT
:
1198 case elfcpp::R_386_GNU_VTENTRY
:
1201 case elfcpp::R_X86_64_64
:
1202 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1205 case elfcpp::R_X86_64_PC64
:
1206 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1210 case elfcpp::R_X86_64_32
:
1211 // FIXME: we need to verify that value + addend fits into 32 bits:
1212 // uint64_t x = value + addend;
1213 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1214 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1215 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1218 case elfcpp::R_X86_64_32S
:
1219 // FIXME: we need to verify that value + addend fits into 32 bits:
1220 // int64_t x = value + addend; // note this quantity is signed!
1221 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1222 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1225 case elfcpp::R_X86_64_PC32
:
1226 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1230 case elfcpp::R_X86_64_16
:
1231 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
1234 case elfcpp::R_X86_64_PC16
:
1235 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
1239 case elfcpp::R_X86_64_8
:
1240 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
1243 case elfcpp::R_X86_64_PC8
:
1244 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
1248 case elfcpp::R_X86_64_PLT32
:
1249 gold_assert(gsym
->has_plt_offset()
1250 || gsym
->final_value_is_known());
1251 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1255 case elfcpp::R_X86_64_GOT32
:
1256 gold_assert(have_got_offset
);
1257 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
1260 case elfcpp::R_X86_64_GOTPC32
:
1263 elfcpp::Elf_types
<64>::Elf_Addr value
;
1264 value
= target
->got_section(NULL
, NULL
)->address();
1265 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1269 case elfcpp::R_X86_64_GOT64
:
1270 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1271 // Since we always add a PLT entry, this is equivalent.
1272 case elfcpp::R_X86_64_GOTPLT64
: // TODO(csilvers): correct?
1273 gold_assert(have_got_offset
);
1274 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
1277 case elfcpp::R_X86_64_GOTPC64
:
1280 elfcpp::Elf_types
<64>::Elf_Addr value
;
1281 value
= target
->got_section(NULL
, NULL
)->address();
1282 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1286 case elfcpp::R_X86_64_GOTOFF64
:
1288 elfcpp::Elf_types
<64>::Elf_Addr value
;
1289 value
= (psymval
->value(object
, 0)
1290 - target
->got_section(NULL
, NULL
)->address());
1291 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
1295 case elfcpp::R_X86_64_GOTPCREL
:
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>::pcrela32(view
, value
, addend
, address
);
1304 case elfcpp::R_X86_64_GOTPCREL64
:
1306 gold_assert(have_got_offset
);
1307 elfcpp::Elf_types
<64>::Elf_Addr value
;
1308 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1309 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1313 case elfcpp::R_X86_64_COPY
:
1314 case elfcpp::R_X86_64_GLOB_DAT
:
1315 case elfcpp::R_X86_64_JUMP_SLOT
:
1316 case elfcpp::R_X86_64_RELATIVE
:
1317 // These are outstanding tls relocs, which are unexpected when linking
1318 case elfcpp::R_X86_64_TPOFF64
:
1319 case elfcpp::R_X86_64_DTPMOD64
:
1320 case elfcpp::R_X86_64_TLSDESC
:
1321 fprintf(stderr
, _("%s: %s: unexpected reloc %u in object file\n"),
1323 relinfo
->location(relnum
, rela
.get_r_offset()).c_str(),
1328 // These are initial tls relocs, which are expected when linking
1329 case elfcpp::R_X86_64_TLSGD
:
1330 case elfcpp::R_X86_64_TLSLD
:
1331 case elfcpp::R_X86_64_GOTTPOFF
:
1332 case elfcpp::R_X86_64_TPOFF32
:
1333 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1334 case elfcpp::R_X86_64_TLSDESC_CALL
:
1335 case elfcpp::R_X86_64_DTPOFF32
:
1336 case elfcpp::R_X86_64_DTPOFF64
:
1337 this->relocate_tls(relinfo
, relnum
, rela
, r_type
, gsym
, psymval
, view
,
1338 address
, view_size
);
1341 case elfcpp::R_X86_64_SIZE32
: // TODO(csilvers): correct?
1342 case elfcpp::R_X86_64_SIZE64
: // TODO(csilvers): correct?
1343 case elfcpp::R_X86_64_PLTOFF64
: // TODO(csilvers): implement me!
1345 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1347 relinfo
->location(relnum
, rela
.get_r_offset()).c_str(),
1356 // Perform a TLS relocation.
1359 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
1361 const elfcpp::Rela
<64, false>& rel
,
1362 unsigned int r_type
,
1363 const Sized_symbol
<64>* gsym
,
1364 const Symbol_value
<64>* psymval
,
1365 unsigned char* view
,
1366 elfcpp::Elf_types
<64>::Elf_Addr
,
1369 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1370 if (tls_segment
== NULL
)
1372 fprintf(stderr
, _("%s: %s: TLS reloc but no TLS segment\n"),
1374 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1378 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1380 const bool is_final
= (gsym
== NULL
1381 ? !parameters
->output_is_shared()
1382 : gsym
->final_value_is_known());
1383 const tls::Tls_optimization optimized_type
1384 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1387 case elfcpp::R_X86_64_TPOFF32
: // Local-exec reloc
1388 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1389 Relocate_functions
<64, false>::rel32(view
, value
);
1392 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec reloc
1393 if (optimized_type
== tls::TLSOPT_TO_LE
)
1395 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1396 rel
, r_type
, value
, view
,
1400 fprintf(stderr
, _("%s: %s: unsupported reloc type %u\n"),
1402 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1407 case elfcpp::R_X86_64_TLSGD
:
1408 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1409 case elfcpp::R_X86_64_TLSDESC_CALL
:
1410 if (optimized_type
== tls::TLSOPT_TO_LE
)
1412 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1413 rel
, r_type
, value
, view
,
1417 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1419 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1424 case elfcpp::R_X86_64_TLSLD
:
1425 if (optimized_type
== tls::TLSOPT_TO_LE
)
1427 // FIXME: implement ld_to_le
1429 fprintf(stderr
, _("%s: %s: unsupported reloc %u\n"),
1431 relinfo
->location(relnum
, rel
.get_r_offset()).c_str(),
1436 case elfcpp::R_X86_64_DTPOFF32
:
1437 if (optimized_type
== tls::TLSOPT_TO_LE
)
1438 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1440 value
= value
- tls_segment
->vaddr();
1441 Relocate_functions
<64, false>::rel32(view
, value
);
1444 case elfcpp::R_X86_64_DTPOFF64
:
1445 if (optimized_type
== tls::TLSOPT_TO_LE
)
1446 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1448 value
= value
- tls_segment
->vaddr();
1449 Relocate_functions
<64, false>::rel64(view
, value
);
1454 // Do a relocation in which we convert a TLS Initial-Exec to a
1458 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
1460 Output_segment
* tls_segment
,
1461 const elfcpp::Rela
<64, false>& rel
,
1463 elfcpp::Elf_types
<64>::Elf_Addr value
,
1464 unsigned char* view
,
1467 // We need to examine the opcodes to figure out which instruction we
1470 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
1471 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
1473 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -3);
1474 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 4);
1476 unsigned char op1
= view
[-3];
1477 unsigned char op2
= view
[-2];
1478 unsigned char op3
= view
[-1];
1479 unsigned char reg
= op3
>> 3;
1487 view
[-1] = 0xc0 | reg
;
1491 // Special handling for %rsp.
1495 view
[-1] = 0xc0 | reg
;
1503 view
[-1] = 0x80 | reg
| (reg
<< 3);
1506 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1507 Relocate_functions
<64, false>::rela32(view
, value
, 0);
1510 // Do a relocation in which we convert a TLS General-Dynamic to a
1514 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
1516 Output_segment
* tls_segment
,
1517 const elfcpp::Rela
<64, false>& rel
,
1519 elfcpp::Elf_types
<64>::Elf_Addr value
,
1520 unsigned char* view
,
1523 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
1524 // .word 0x6666; rex64; call __tls_get_addr
1525 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
1527 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, -4);
1528 Target_x86_64::Relocate::check_range(relinfo
, relnum
, rel
, view_size
, 12);
1530 Target_x86_64::Relocate::check_tls(relinfo
, relnum
, rel
,
1531 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4)
1533 Target_x86_64::Relocate::check_tls(relinfo
, relnum
, rel
,
1534 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4)
1537 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
1539 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1540 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
1542 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1544 this->skip_call_tls_get_addr_
= true;
1547 // Check the range for a TLS relocation.
1550 Target_x86_64::Relocate::check_range(const Relocate_info
<64, false>* relinfo
,
1552 const elfcpp::Rela
<64, false>& rel
,
1553 off_t view_size
, off_t off
)
1555 off_t offset
= rel
.get_r_offset() + off
;
1556 if (offset
< 0 || offset
> view_size
)
1558 fprintf(stderr
, _("%s: %s: TLS relocation out of range\n"),
1560 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1565 // Check the validity of a TLS relocation. This is like assert.
1568 Target_x86_64::Relocate::check_tls(const Relocate_info
<64, false>* relinfo
,
1570 const elfcpp::Rela
<64, false>& rel
,
1576 _("%s: %s: TLS relocation against invalid instruction\n"),
1578 relinfo
->location(relnum
, rel
.get_r_offset()).c_str());
1583 // Relocate section data.
1586 Target_x86_64::relocate_section(const Relocate_info
<64, false>* relinfo
,
1587 unsigned int sh_type
,
1588 const unsigned char* prelocs
,
1590 unsigned char* view
,
1591 elfcpp::Elf_types
<64>::Elf_Addr address
,
1594 gold_assert(sh_type
== elfcpp::SHT_RELA
);
1596 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1597 Target_x86_64::Relocate
>(
1607 // Return the value to use for a dynamic which requires special
1608 // treatment. This is how we support equality comparisons of function
1609 // pointers across shared library boundaries, as described in the
1610 // processor specific ABI supplement.
1613 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
1615 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
1616 return this->plt_section()->address() + gsym
->plt_offset();
1619 // Return a string used to fill a code section with nops to take up
1620 // the specified length.
1623 Target_x86_64::do_code_fill(off_t length
)
1627 // Build a jmpq instruction to skip over the bytes.
1628 unsigned char jmp
[5];
1630 elfcpp::Swap_unaligned
<64, false>::writeval(jmp
+ 1, length
- 5);
1631 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
1632 + std::string(length
- 5, '\0'));
1635 // Nop sequences of various lengths.
1636 const char nop1
[1] = { 0x90 }; // nop
1637 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
1638 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1639 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1640 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1641 0x00 }; // leal 0(%esi,1),%esi
1642 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1644 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1646 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1647 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1648 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1649 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1651 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1652 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1654 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1655 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1657 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1658 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1659 0x00, 0x00, 0x00, 0x00 };
1660 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1661 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1662 0x27, 0x00, 0x00, 0x00,
1664 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1665 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1666 0xbc, 0x27, 0x00, 0x00,
1668 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1669 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1670 0x90, 0x90, 0x90, 0x90,
1673 const char* nops
[16] = {
1675 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
1676 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
1679 return std::string(nops
[length
], length
);
1682 // The selector for x86_64 object files.
1684 class Target_selector_x86_64
: public Target_selector
1687 Target_selector_x86_64()
1688 : Target_selector(elfcpp::EM_X86_64
, 64, false)
1692 recognize(int machine
, int osabi
, int abiversion
);
1695 Target_x86_64
* target_
;
1698 // Recognize an x86_64 object file when we already know that the machine
1699 // number is EM_X86_64.
1702 Target_selector_x86_64::recognize(int, int, int)
1704 if (this->target_
== NULL
)
1705 this->target_
= new Target_x86_64();
1706 return this->target_
;
1709 Target_selector_x86_64 target_selector_x86_64
;
1711 } // End anonymous namespace.