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 General-Dynamic to Local-Exec transition.
179 tls_gd_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 Local-Dynamic to Local-Exec transition.
188 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
189 Output_segment
* tls_segment
,
190 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
191 elfcpp::Elf_types
<64>::Elf_Addr value
,
195 // Do a TLS Initial-Exec to Local-Exec transition.
197 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
198 Output_segment
* tls_segment
,
199 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
200 elfcpp::Elf_types
<64>::Elf_Addr value
,
204 // This is set if we should skip the next reloc, which should be a
205 // PLT32 reloc against ___tls_get_addr.
206 bool skip_call_tls_get_addr_
;
209 // Adjust TLS relocation type based on the options and whether this
210 // is a local symbol.
211 static tls::Tls_optimization
212 optimize_tls_reloc(bool is_final
, int r_type
);
214 // Get the GOT section, creating it if necessary.
215 Output_data_got
<64, false>*
216 got_section(Symbol_table
*, Layout
*);
218 // Create a PLT entry for a global symbol.
220 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
222 // Get the PLT section.
223 Output_data_plt_x86_64
*
226 gold_assert(this->plt_
!= NULL
);
230 // Get the dynamic reloc section, creating it if necessary.
232 rela_dyn_section(Layout
*);
234 // Copy a relocation against a global symbol.
236 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
237 Sized_relobj
<64, false>*, unsigned int,
238 Symbol
*, const elfcpp::Rela
<64, false>&);
240 // Information about this specific target which we pass to the
241 // general Target structure.
242 static const Target::Target_info x86_64_info
;
245 Output_data_got
<64, false>* got_
;
247 Output_data_plt_x86_64
* plt_
;
248 // The GOT PLT section.
249 Output_data_space
* got_plt_
;
250 // The dynamic reloc section.
251 Reloc_section
* rela_dyn_
;
252 // Relocs saved to avoid a COPY reloc.
253 Copy_relocs
<64, false>* copy_relocs_
;
254 // Space for variables copied with a COPY reloc.
255 Output_data_space
* dynbss_
;
258 const Target::Target_info
Target_x86_64::x86_64_info
=
261 false, // is_big_endian
262 elfcpp::EM_X86_64
, // machine_code
263 false, // has_make_symbol
264 false, // has_resolve
265 true, // has_code_fill
266 true, // is_default_stack_executable
267 "/lib/ld64.so.1", // program interpreter
268 0x400000, // default_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 this->got_plt_
= new Output_data_space(8);
293 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
294 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
297 // The first three entries are reserved.
298 this->got_plt_
->set_space_size(3 * 8);
300 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
301 symtab
->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL
,
303 0, 0, elfcpp::STT_OBJECT
,
305 elfcpp::STV_HIDDEN
, 0,
312 // Get the dynamic reloc section, creating it if necessary.
314 Target_x86_64::Reloc_section
*
315 Target_x86_64::rela_dyn_section(Layout
* layout
)
317 if (this->rela_dyn_
== NULL
)
319 gold_assert(layout
!= NULL
);
320 this->rela_dyn_
= new Reloc_section();
321 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
322 elfcpp::SHF_ALLOC
, this->rela_dyn_
);
324 return this->rela_dyn_
;
327 // A class to handle the PLT data.
329 class Output_data_plt_x86_64
: public Output_section_data
332 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
334 Output_data_plt_x86_64(Layout
*, Output_data_space
*);
336 // Add an entry to the PLT.
338 add_entry(Symbol
* gsym
);
340 // Return the .rel.plt section data.
343 { return this->rel_
; }
347 do_adjust_output_section(Output_section
* os
);
350 // The size of an entry in the PLT.
351 static const int plt_entry_size
= 16;
353 // The first entry in the PLT.
354 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
355 // procedure linkage table for both programs and shared objects."
356 static unsigned char first_plt_entry
[plt_entry_size
];
358 // Other entries in the PLT for an executable.
359 static unsigned char plt_entry
[plt_entry_size
];
361 // Set the final size.
363 do_set_address(uint64_t, off_t
)
364 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
366 // Write out the PLT data.
368 do_write(Output_file
*);
370 // The reloc section.
372 // The .got.plt section.
373 Output_data_space
* got_plt_
;
374 // The number of PLT entries.
378 // Create the PLT section. The ordinary .got section is an argument,
379 // since we need to refer to the start. We also create our own .got
380 // section just for PLT entries.
382 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout
* layout
,
383 Output_data_space
* got_plt
)
384 : Output_section_data(8), got_plt_(got_plt
), count_(0)
386 this->rel_
= new Reloc_section();
387 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
388 elfcpp::SHF_ALLOC
, this->rel_
);
392 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
394 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
395 // linker, and so do we.
399 // Add an entry to the PLT.
402 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
404 gold_assert(!gsym
->has_plt_offset());
406 // Note that when setting the PLT offset we skip the initial
407 // reserved PLT entry.
408 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
412 off_t got_offset
= this->got_plt_
->data_size();
414 // Every PLT entry needs a GOT entry which points back to the PLT
415 // entry (this will be changed by the dynamic linker, normally
416 // lazily when the function is called).
417 this->got_plt_
->set_space_size(got_offset
+ 8);
419 // Every PLT entry needs a reloc.
420 gsym
->set_needs_dynsym_entry();
421 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
424 // Note that we don't need to save the symbol. The contents of the
425 // PLT are independent of which symbols are used. The symbols only
426 // appear in the relocations.
429 // The first entry in the PLT for an executable.
431 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
433 // From AMD64 ABI Draft 0.98, page 76
434 0xff, 0x35, // pushq contents of memory address
435 0, 0, 0, 0, // replaced with address of .got + 4
436 0xff, 0x25, // jmp indirect
437 0, 0, 0, 0, // replaced with address of .got + 8
438 0x90, 0x90, 0x90, 0x90 // noop (x4)
441 // Subsequent entries in the PLT for an executable.
443 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
445 // From AMD64 ABI Draft 0.98, page 76
446 0xff, 0x25, // jmpq indirect
447 0, 0, 0, 0, // replaced with address of symbol in .got
448 0x68, // pushq immediate
449 0, 0, 0, 0, // replaced with offset into relocation table
450 0xe9, // jmpq relative
451 0, 0, 0, 0 // replaced with offset to start of .plt
454 // Write out the PLT. This uses the hand-coded instructions above,
455 // and adjusts them as needed. This is specified by the AMD64 ABI.
458 Output_data_plt_x86_64::do_write(Output_file
* of
)
460 const off_t offset
= this->offset();
461 const off_t oview_size
= this->data_size();
462 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
464 const off_t got_file_offset
= this->got_plt_
->offset();
465 const off_t got_size
= this->got_plt_
->data_size();
466 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
469 unsigned char* pov
= oview
;
471 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
472 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
474 memcpy(pov
, first_plt_entry
, plt_entry_size
);
475 if (!parameters
->output_is_shared())
477 // We do a jmp relative to the PC at the end of this instruction.
478 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 8
479 - (plt_address
+ 6));
480 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 16
481 - (plt_address
+ 12));
483 pov
+= plt_entry_size
;
485 unsigned char* got_pov
= got_view
;
487 memset(got_pov
, 0, 24);
490 unsigned int plt_offset
= plt_entry_size
;
491 unsigned int got_offset
= 24;
492 const unsigned int count
= this->count_
;
493 for (unsigned int plt_index
= 0;
496 pov
+= plt_entry_size
,
498 plt_offset
+= plt_entry_size
,
501 // Set and adjust the PLT entry itself.
502 memcpy(pov
, plt_entry
, plt_entry_size
);
503 if (parameters
->output_is_shared())
504 // FIXME(csilvers): what's the right thing to write here?
505 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
507 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
508 (got_address
+ got_offset
509 - (plt_address
+ plt_offset
512 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
513 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
514 - (plt_offset
+ plt_entry_size
));
516 // Set the entry in the GOT.
517 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
520 gold_assert(pov
- oview
== oview_size
);
521 gold_assert(got_pov
- got_view
== got_size
);
523 of
->write_output_view(offset
, oview_size
, oview
);
524 of
->write_output_view(got_file_offset
, got_size
, got_view
);
527 // Create a PLT entry for a global symbol.
530 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
533 if (gsym
->has_plt_offset())
536 if (this->plt_
== NULL
)
538 // Create the GOT sections first.
539 this->got_section(symtab
, layout
);
541 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_plt_
);
542 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
544 | elfcpp::SHF_EXECINSTR
),
548 this->plt_
->add_entry(gsym
);
551 // Handle a relocation against a non-function symbol defined in a
552 // dynamic object. The traditional way to handle this is to generate
553 // a COPY relocation to copy the variable at runtime from the shared
554 // object into the executable's data segment. However, this is
555 // undesirable in general, as if the size of the object changes in the
556 // dynamic object, the executable will no longer work correctly. If
557 // this relocation is in a writable section, then we can create a
558 // dynamic reloc and the dynamic linker will resolve it to the correct
559 // address at runtime. However, we do not want do that if the
560 // relocation is in a read-only section, as it would prevent the
561 // readonly segment from being shared. And if we have to eventually
562 // generate a COPY reloc, then any dynamic relocations will be
563 // useless. So this means that if this is a writable section, we need
564 // to save the relocation until we see whether we have to create a
565 // COPY relocation for this symbol for any other relocation.
568 Target_x86_64::copy_reloc(const General_options
* options
,
569 Symbol_table
* symtab
,
571 Sized_relobj
<64, false>* object
,
572 unsigned int data_shndx
, Symbol
* gsym
,
573 const elfcpp::Rela
<64, false>& rela
)
575 Sized_symbol
<64>* ssym
;
576 ssym
= symtab
->get_sized_symbol
SELECT_SIZE_NAME(64) (gsym
579 if (!Copy_relocs
<64, false>::need_copy_reloc(options
, object
,
582 // So far we do not need a COPY reloc. Save this relocation.
583 // If it turns out that we never need a COPY reloc for this
584 // symbol, then we will emit the relocation.
585 if (this->copy_relocs_
== NULL
)
586 this->copy_relocs_
= new Copy_relocs
<64, false>();
587 this->copy_relocs_
->save(ssym
, object
, data_shndx
, rela
);
591 // Allocate space for this symbol in the .bss section.
593 elfcpp::Elf_types
<64>::Elf_WXword symsize
= ssym
->symsize();
595 // There is no defined way to determine the required alignment
596 // of the symbol. We pick the alignment based on the size. We
597 // set an arbitrary maximum of 256.
599 for (align
= 1; align
< 512; align
<<= 1)
600 if ((symsize
& align
) != 0)
603 if (this->dynbss_
== NULL
)
605 this->dynbss_
= new Output_data_space(align
);
606 layout
->add_output_section_data(".bss",
609 | elfcpp::SHF_WRITE
),
613 Output_data_space
* dynbss
= this->dynbss_
;
615 if (align
> dynbss
->addralign())
616 dynbss
->set_space_alignment(align
);
618 off_t dynbss_size
= dynbss
->data_size();
619 dynbss_size
= align_address(dynbss_size
, align
);
620 off_t offset
= dynbss_size
;
621 dynbss
->set_space_size(dynbss_size
+ symsize
);
623 symtab
->define_with_copy_reloc(this, ssym
, dynbss
, offset
);
625 // Add the COPY reloc.
626 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
627 rela_dyn
->add_global(ssym
, elfcpp::R_X86_64_COPY
, dynbss
, offset
, 0);
632 // Optimize the TLS relocation type based on what we know about the
633 // symbol. IS_FINAL is true if the final address of this symbol is
634 // known at link time.
636 tls::Tls_optimization
637 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
639 // If we are generating a shared library, then we can't do anything
641 if (parameters
->output_is_shared())
642 return tls::TLSOPT_NONE
;
646 case elfcpp::R_X86_64_TLSGD
:
647 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
648 case elfcpp::R_X86_64_TLSDESC_CALL
:
649 // These are General-Dynamic which permits fully general TLS
650 // access. Since we know that we are generating an executable,
651 // we can convert this to Initial-Exec. If we also know that
652 // this is a local symbol, we can further switch to Local-Exec.
654 return tls::TLSOPT_TO_LE
;
655 return tls::TLSOPT_TO_IE
;
657 case elfcpp::R_X86_64_TLSLD
:
658 // This is Local-Dynamic, which refers to a local symbol in the
659 // dynamic TLS block. Since we know that we generating an
660 // executable, we can switch to Local-Exec.
661 return tls::TLSOPT_TO_LE
;
663 case elfcpp::R_X86_64_DTPOFF32
:
664 case elfcpp::R_X86_64_DTPOFF64
:
665 // Another Local-Dynamic reloc.
666 return tls::TLSOPT_TO_LE
;
668 case elfcpp::R_X86_64_GOTTPOFF
:
669 // These are Initial-Exec relocs which get the thread offset
670 // from the GOT. If we know that we are linking against the
671 // local symbol, we can switch to Local-Exec, which links the
672 // thread offset into the instruction.
674 return tls::TLSOPT_TO_LE
;
675 return tls::TLSOPT_NONE
;
677 case elfcpp::R_X86_64_TPOFF32
:
678 // When we already have Local-Exec, there is nothing further we
680 return tls::TLSOPT_NONE
;
687 // Report an unsupported relocation against a local symbol.
690 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
693 gold_error(_("%s: unsupported reloc %u against local symbol"),
694 object
->name().c_str(), r_type
);
697 // Scan a relocation for a local symbol.
700 Target_x86_64::Scan::local(const General_options
&,
701 Symbol_table
* symtab
,
703 Target_x86_64
* target
,
704 Sized_relobj
<64, false>* object
,
705 unsigned int data_shndx
,
706 const elfcpp::Rela
<64, false>& reloc
,
708 const elfcpp::Sym
<64, false>&)
712 case elfcpp::R_X86_64_NONE
:
713 case elfcpp::R_386_GNU_VTINHERIT
:
714 case elfcpp::R_386_GNU_VTENTRY
:
717 case elfcpp::R_X86_64_64
:
718 case elfcpp::R_X86_64_32
:
719 case elfcpp::R_X86_64_32S
:
720 case elfcpp::R_X86_64_16
:
721 case elfcpp::R_X86_64_8
:
722 // FIXME: If we are generating a shared object we need to copy
723 // this relocation into the object.
724 gold_assert(!parameters
->output_is_shared());
727 case elfcpp::R_X86_64_PC64
:
728 case elfcpp::R_X86_64_PC32
:
729 case elfcpp::R_X86_64_PC16
:
730 case elfcpp::R_X86_64_PC8
:
733 case elfcpp::R_X86_64_PLT32
:
734 // Since we know this is a local symbol, we can handle this as a
738 case elfcpp::R_X86_64_GOTPC32
:
739 case elfcpp::R_X86_64_GOTOFF64
:
740 case elfcpp::R_X86_64_GOTPC64
:
741 case elfcpp::R_X86_64_PLTOFF64
:
742 // We need a GOT section.
743 target
->got_section(symtab
, layout
);
744 // For PLTOFF64, we'd normally want a PLT section, but since we
745 // know this is a local symbol, no PLT is needed.
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
:
752 case elfcpp::R_X86_64_GOTPLT64
:
754 // The symbol requires a GOT entry.
755 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
756 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
757 if (got
->add_local(object
, r_sym
))
759 // If we are generating a shared object, we need to add a
760 // dynamic RELATIVE relocation for this symbol.
761 if (parameters
->output_is_shared())
763 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
764 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
765 data_shndx
, reloc
.get_r_offset(), 0);
768 // For GOTPLT64, we'd normally want a PLT section, but since
769 // we know this is a local symbol, no PLT is needed.
773 case elfcpp::R_X86_64_COPY
:
774 case elfcpp::R_X86_64_GLOB_DAT
:
775 case elfcpp::R_X86_64_JUMP_SLOT
:
776 case elfcpp::R_X86_64_RELATIVE
:
777 // These are outstanding tls relocs, which are unexpected when linking
778 case elfcpp::R_X86_64_TPOFF64
:
779 case elfcpp::R_X86_64_DTPMOD64
:
780 case elfcpp::R_X86_64_TLSDESC
:
781 gold_error(_("%s: unexpected reloc %u in object file"),
782 object
->name().c_str(), r_type
);
785 // These are initial tls relocs, which are expected when linking
786 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
787 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
788 case elfcpp::R_X86_64_TLSDESC_CALL
:
789 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
790 case elfcpp::R_X86_64_DTPOFF32
:
791 case elfcpp::R_X86_64_DTPOFF64
:
792 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
793 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
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_TLSGD
: // General-dynamic
801 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
802 case elfcpp::R_X86_64_TLSDESC_CALL
:
803 // FIXME: If not relaxing to LE, we need to generate
804 // DTPMOD64 and DTPOFF64 relocs.
805 if (optimized_type
!= tls::TLSOPT_TO_LE
)
806 unsupported_reloc_local(object
, r_type
);
809 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
810 case elfcpp::R_X86_64_DTPOFF32
:
811 case elfcpp::R_X86_64_DTPOFF64
:
812 // FIXME: If not relaxing to LE, we need to generate a
814 if (optimized_type
!= tls::TLSOPT_TO_LE
)
815 unsupported_reloc_local(object
, r_type
);
818 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
819 // FIXME: If not relaxing to LE, we need to generate a
821 if (optimized_type
!= tls::TLSOPT_TO_LE
)
822 unsupported_reloc_local(object
, r_type
);
825 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
826 // FIXME: If generating a shared object, we need to copy
827 // this relocation into the object.
828 gold_assert(!output_is_shared
);
837 case elfcpp::R_X86_64_SIZE32
:
838 case elfcpp::R_X86_64_SIZE64
:
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);
938 // For GOTPLT64, we also need a PLT entry (but only if the
939 // symbol is not fully resolved).
940 if (r_type
== elfcpp::R_X86_64_GOTPLT64
941 && !gsym
->final_value_is_known())
942 target
->make_plt_entry(symtab
, layout
, gsym
);
946 case elfcpp::R_X86_64_PLT32
:
947 // If the symbol is fully resolved, this is just a PC32 reloc.
948 // Otherwise we need a PLT entry.
949 if (gsym
->final_value_is_known())
951 target
->make_plt_entry(symtab
, layout
, gsym
);
954 case elfcpp::R_X86_64_GOTPC32
:
955 case elfcpp::R_X86_64_GOTOFF64
:
956 case elfcpp::R_X86_64_GOTPC64
:
957 case elfcpp::R_X86_64_PLTOFF64
:
958 // We need a GOT section.
959 target
->got_section(symtab
, layout
);
960 // For PLTOFF64, we also need a PLT entry (but only if the
961 // symbol is not fully resolved).
962 if (r_type
== elfcpp::R_X86_64_PLTOFF64
963 && !gsym
->final_value_is_known())
964 target
->make_plt_entry(symtab
, layout
, gsym
);
967 case elfcpp::R_X86_64_COPY
:
968 case elfcpp::R_X86_64_GLOB_DAT
:
969 case elfcpp::R_X86_64_JUMP_SLOT
:
970 case elfcpp::R_X86_64_RELATIVE
:
971 // These are outstanding tls relocs, which are unexpected when linking
972 case elfcpp::R_X86_64_TPOFF64
:
973 case elfcpp::R_X86_64_DTPMOD64
:
974 case elfcpp::R_X86_64_TLSDESC
:
975 gold_error(_("%s: unexpected reloc %u in object file"),
976 object
->name().c_str(), r_type
);
979 // These are initial tls relocs, which are expected for global()
980 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
981 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
982 case elfcpp::R_X86_64_TLSDESC_CALL
:
983 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
984 case elfcpp::R_X86_64_DTPOFF32
:
985 case elfcpp::R_X86_64_DTPOFF64
:
986 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
987 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
989 const bool is_final
= gsym
->final_value_is_known();
990 const tls::Tls_optimization optimized_type
991 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
994 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
995 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
996 case elfcpp::R_X86_64_TLSDESC_CALL
:
997 // FIXME: If not relaxing to LE, we need to generate
998 // DTPMOD64 and DTPOFF64, or TLSDESC, relocs.
999 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1000 unsupported_reloc_global(object
, r_type
, gsym
);
1003 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1004 case elfcpp::R_X86_64_DTPOFF32
:
1005 case elfcpp::R_X86_64_DTPOFF64
:
1006 // FIXME: If not relaxing to LE, we need to generate a
1008 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1009 unsupported_reloc_global(object
, r_type
, gsym
);
1012 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1013 // FIXME: If not relaxing to LE, we need to generate a
1015 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1016 unsupported_reloc_global(object
, r_type
, gsym
);
1019 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1020 // FIXME: If generating a shared object, we need to copy
1021 // this relocation into the object.
1022 gold_assert(is_final
);
1031 case elfcpp::R_X86_64_SIZE32
:
1032 case elfcpp::R_X86_64_SIZE64
:
1034 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1035 object
->name().c_str(), r_type
, gsym
->name());
1040 // Scan relocations for a section.
1043 Target_x86_64::scan_relocs(const General_options
& options
,
1044 Symbol_table
* symtab
,
1046 Sized_relobj
<64, false>* object
,
1047 unsigned int data_shndx
,
1048 unsigned int sh_type
,
1049 const unsigned char* prelocs
,
1051 size_t local_symbol_count
,
1052 const unsigned char* plocal_symbols
,
1053 Symbol
** global_symbols
)
1055 if (sh_type
== elfcpp::SHT_REL
)
1057 gold_error(_("%s: unsupported REL reloc section"),
1058 object
->name().c_str());
1062 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1063 Target_x86_64::Scan
>(
1077 // Finalize the sections.
1080 Target_x86_64::do_finalize_sections(Layout
* layout
)
1082 // Fill in some more dynamic tags.
1083 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1086 if (this->got_plt_
!= NULL
)
1087 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1089 if (this->plt_
!= NULL
)
1091 const Output_data
* od
= this->plt_
->rel_plt();
1092 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1093 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1094 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_RELA
);
1097 if (this->rela_dyn_
!= NULL
)
1099 const Output_data
* od
= this->rela_dyn_
;
1100 odyn
->add_section_address(elfcpp::DT_RELA
, od
);
1101 odyn
->add_section_size(elfcpp::DT_RELASZ
, od
);
1102 odyn
->add_constant(elfcpp::DT_RELAENT
,
1103 elfcpp::Elf_sizes
<64>::rela_size
);
1106 if (!parameters
->output_is_shared())
1108 // The value of the DT_DEBUG tag is filled in by the dynamic
1109 // linker at run time, and used by the debugger.
1110 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1114 // Emit any relocs we saved in an attempt to avoid generating COPY
1116 if (this->copy_relocs_
== NULL
)
1118 if (this->copy_relocs_
->any_to_emit())
1120 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1121 this->copy_relocs_
->emit(rela_dyn
);
1123 delete this->copy_relocs_
;
1124 this->copy_relocs_
= NULL
;
1127 // Perform a relocation.
1130 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1131 Target_x86_64
* target
,
1133 const elfcpp::Rela
<64, false>& rela
,
1134 unsigned int r_type
,
1135 const Sized_symbol
<64>* gsym
,
1136 const Symbol_value
<64>* psymval
,
1137 unsigned char* view
,
1138 elfcpp::Elf_types
<64>::Elf_Addr address
,
1141 if (this->skip_call_tls_get_addr_
)
1143 if (r_type
!= elfcpp::R_X86_64_PLT32
1145 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1147 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1148 _("missing expected TLS relocation"));
1152 this->skip_call_tls_get_addr_
= false;
1157 // Pick the value to use for symbols defined in shared objects.
1158 Symbol_value
<64> symval
;
1159 if (gsym
!= NULL
&& gsym
->is_from_dynobj() && gsym
->has_plt_offset())
1161 symval
.set_output_value(target
->plt_section()->address()
1162 + gsym
->plt_offset());
1166 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1167 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1169 // Get the GOT offset if needed.
1170 bool have_got_offset
= false;
1171 unsigned int got_offset
= 0;
1174 case elfcpp::R_X86_64_GOT32
:
1175 case elfcpp::R_X86_64_GOT64
:
1176 case elfcpp::R_X86_64_GOTPLT64
:
1177 case elfcpp::R_X86_64_GOTPCREL
:
1178 case elfcpp::R_X86_64_GOTPCREL64
:
1181 gold_assert(gsym
->has_got_offset());
1182 got_offset
= gsym
->got_offset();
1186 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1187 got_offset
= object
->local_got_offset(r_sym
);
1189 have_got_offset
= true;
1198 case elfcpp::R_X86_64_NONE
:
1199 case elfcpp::R_386_GNU_VTINHERIT
:
1200 case elfcpp::R_386_GNU_VTENTRY
:
1203 case elfcpp::R_X86_64_64
:
1204 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1207 case elfcpp::R_X86_64_PC64
:
1208 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1212 case elfcpp::R_X86_64_32
:
1213 // FIXME: we need to verify that value + addend fits into 32 bits:
1214 // uint64_t x = value + addend;
1215 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1216 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1217 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1220 case elfcpp::R_X86_64_32S
:
1221 // FIXME: we need to verify that value + addend fits into 32 bits:
1222 // int64_t x = value + addend; // note this quantity is signed!
1223 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1224 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1227 case elfcpp::R_X86_64_PC32
:
1228 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1232 case elfcpp::R_X86_64_16
:
1233 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
1236 case elfcpp::R_X86_64_PC16
:
1237 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
1241 case elfcpp::R_X86_64_8
:
1242 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
1245 case elfcpp::R_X86_64_PC8
:
1246 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
1250 case elfcpp::R_X86_64_PLT32
:
1251 gold_assert(gsym
== NULL
1252 || gsym
->has_plt_offset()
1253 || gsym
->final_value_is_known());
1254 // Note: while this code looks the same as for R_X86_64_PC32, it
1255 // behaves differently because psymval was set to point to
1256 // the PLT entry, rather than the symbol, in Scan::global().
1257 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1261 case elfcpp::R_X86_64_PLTOFF64
:
1264 gold_assert(gsym
->has_plt_offset()
1265 || gsym
->final_value_is_known());
1266 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
1267 got_address
= target
->got_section(NULL
, NULL
)->address();
1268 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
1269 addend
- got_address
);
1272 case elfcpp::R_X86_64_GOT32
:
1273 gold_assert(have_got_offset
);
1274 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
1277 case elfcpp::R_X86_64_GOTPC32
:
1280 elfcpp::Elf_types
<64>::Elf_Addr value
;
1281 value
= target
->got_section(NULL
, NULL
)->address();
1282 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1286 case elfcpp::R_X86_64_GOT64
:
1287 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1288 // Since we always add a PLT entry, this is equivalent.
1289 case elfcpp::R_X86_64_GOTPLT64
:
1290 gold_assert(have_got_offset
);
1291 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
1294 case elfcpp::R_X86_64_GOTPC64
:
1297 elfcpp::Elf_types
<64>::Elf_Addr value
;
1298 value
= target
->got_section(NULL
, NULL
)->address();
1299 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1303 case elfcpp::R_X86_64_GOTOFF64
:
1305 elfcpp::Elf_types
<64>::Elf_Addr value
;
1306 value
= (psymval
->value(object
, 0)
1307 - target
->got_section(NULL
, NULL
)->address());
1308 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
1312 case elfcpp::R_X86_64_GOTPCREL
:
1314 gold_assert(have_got_offset
);
1315 elfcpp::Elf_types
<64>::Elf_Addr value
;
1316 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1317 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1321 case elfcpp::R_X86_64_GOTPCREL64
:
1323 gold_assert(have_got_offset
);
1324 elfcpp::Elf_types
<64>::Elf_Addr value
;
1325 value
= target
->got_section(NULL
, NULL
)->address() + got_offset
;
1326 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1330 case elfcpp::R_X86_64_COPY
:
1331 case elfcpp::R_X86_64_GLOB_DAT
:
1332 case elfcpp::R_X86_64_JUMP_SLOT
:
1333 case elfcpp::R_X86_64_RELATIVE
:
1334 // These are outstanding tls relocs, which are unexpected when linking
1335 case elfcpp::R_X86_64_TPOFF64
:
1336 case elfcpp::R_X86_64_DTPMOD64
:
1337 case elfcpp::R_X86_64_TLSDESC
:
1338 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1339 _("unexpected reloc %u in object file"),
1343 // These are initial tls relocs, which are expected when linking
1344 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1345 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1346 case elfcpp::R_X86_64_TLSDESC_CALL
:
1347 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1348 case elfcpp::R_X86_64_DTPOFF32
:
1349 case elfcpp::R_X86_64_DTPOFF64
:
1350 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1351 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1352 this->relocate_tls(relinfo
, relnum
, rela
, r_type
, gsym
, psymval
, view
,
1353 address
, view_size
);
1356 case elfcpp::R_X86_64_SIZE32
:
1357 case elfcpp::R_X86_64_SIZE64
:
1359 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1360 _("unsupported reloc %u"),
1368 // Perform a TLS relocation.
1371 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
1373 const elfcpp::Rela
<64, false>& rela
,
1374 unsigned int r_type
,
1375 const Sized_symbol
<64>* gsym
,
1376 const Symbol_value
<64>* psymval
,
1377 unsigned char* view
,
1378 elfcpp::Elf_types
<64>::Elf_Addr
,
1381 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1382 if (tls_segment
== NULL
)
1384 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1385 _("TLS reloc but no TLS segment"));
1389 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1391 const bool is_final
= (gsym
== NULL
1392 ? !parameters
->output_is_shared()
1393 : gsym
->final_value_is_known());
1394 const tls::Tls_optimization optimized_type
1395 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1398 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1399 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1400 case elfcpp::R_X86_64_TLSDESC_CALL
:
1401 if (optimized_type
== tls::TLSOPT_TO_LE
)
1403 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1404 rela
, r_type
, value
, view
,
1408 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1409 _("unsupported reloc %u"), r_type
);
1412 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1413 if (optimized_type
== tls::TLSOPT_TO_LE
)
1415 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
1416 value
, view
, view_size
);
1419 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1420 _("unsupported reloc %u"), r_type
);
1423 case elfcpp::R_X86_64_DTPOFF32
:
1424 if (optimized_type
== tls::TLSOPT_TO_LE
)
1425 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1427 value
= value
- tls_segment
->vaddr();
1428 Relocate_functions
<64, false>::rel32(view
, value
);
1431 case elfcpp::R_X86_64_DTPOFF64
:
1432 if (optimized_type
== tls::TLSOPT_TO_LE
)
1433 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1435 value
= value
- tls_segment
->vaddr();
1436 Relocate_functions
<64, false>::rel64(view
, value
);
1439 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1440 if (optimized_type
== tls::TLSOPT_TO_LE
)
1442 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1443 rela
, r_type
, value
, view
,
1447 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1448 _("unsupported reloc type %u"),
1452 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1453 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1454 Relocate_functions
<64, false>::rel32(view
, value
);
1459 // Do a relocation in which we convert a TLS General-Dynamic to a
1463 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
1465 Output_segment
* tls_segment
,
1466 const elfcpp::Rela
<64, false>& rela
,
1468 elfcpp::Elf_types
<64>::Elf_Addr value
,
1469 unsigned char* view
,
1472 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
1473 // .word 0x6666; rex64; call __tls_get_addr
1474 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
1476 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
1477 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
1479 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1480 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
1481 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1482 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
1484 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
1486 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1487 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
1489 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1491 this->skip_call_tls_get_addr_
= true;
1495 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
1498 const elfcpp::Rela
<64, false>& rela
,
1500 elfcpp::Elf_types
<64>::Elf_Addr
,
1501 unsigned char* view
,
1504 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
1505 // ... leq foo@dtpoff(%rax),%reg
1506 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
1508 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
1509 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
1511 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1512 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
1514 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
1516 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
1518 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1520 this->skip_call_tls_get_addr_
= true;
1523 // Do a relocation in which we convert a TLS Initial-Exec to a
1527 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
1529 Output_segment
* tls_segment
,
1530 const elfcpp::Rela
<64, false>& rela
,
1532 elfcpp::Elf_types
<64>::Elf_Addr value
,
1533 unsigned char* view
,
1536 // We need to examine the opcodes to figure out which instruction we
1539 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
1540 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
1542 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
1543 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
1545 unsigned char op1
= view
[-3];
1546 unsigned char op2
= view
[-2];
1547 unsigned char op3
= view
[-1];
1548 unsigned char reg
= op3
>> 3;
1556 view
[-1] = 0xc0 | reg
;
1560 // Special handling for %rsp.
1564 view
[-1] = 0xc0 | reg
;
1572 view
[-1] = 0x80 | reg
| (reg
<< 3);
1575 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1576 Relocate_functions
<64, false>::rela32(view
, value
, 0);
1579 // Relocate section data.
1582 Target_x86_64::relocate_section(const Relocate_info
<64, false>* relinfo
,
1583 unsigned int sh_type
,
1584 const unsigned char* prelocs
,
1586 unsigned char* view
,
1587 elfcpp::Elf_types
<64>::Elf_Addr address
,
1590 gold_assert(sh_type
== elfcpp::SHT_RELA
);
1592 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1593 Target_x86_64::Relocate
>(
1603 // Return the value to use for a dynamic which requires special
1604 // treatment. This is how we support equality comparisons of function
1605 // pointers across shared library boundaries, as described in the
1606 // processor specific ABI supplement.
1609 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
1611 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
1612 return this->plt_section()->address() + gsym
->plt_offset();
1615 // Return a string used to fill a code section with nops to take up
1616 // the specified length.
1619 Target_x86_64::do_code_fill(off_t length
)
1623 // Build a jmpq instruction to skip over the bytes.
1624 unsigned char jmp
[5];
1626 elfcpp::Swap_unaligned
<64, false>::writeval(jmp
+ 1, length
- 5);
1627 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
1628 + std::string(length
- 5, '\0'));
1631 // Nop sequences of various lengths.
1632 const char nop1
[1] = { 0x90 }; // nop
1633 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
1634 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1635 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1636 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1637 0x00 }; // leal 0(%esi,1),%esi
1638 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1640 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1642 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1643 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1644 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1645 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1647 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1648 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1650 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1651 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1653 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1654 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1655 0x00, 0x00, 0x00, 0x00 };
1656 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1657 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1658 0x27, 0x00, 0x00, 0x00,
1660 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1661 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1662 0xbc, 0x27, 0x00, 0x00,
1664 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1665 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1666 0x90, 0x90, 0x90, 0x90,
1669 const char* nops
[16] = {
1671 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
1672 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
1675 return std::string(nops
[length
], length
);
1678 // The selector for x86_64 object files.
1680 class Target_selector_x86_64
: public Target_selector
1683 Target_selector_x86_64()
1684 : Target_selector(elfcpp::EM_X86_64
, 64, false)
1688 recognize(int machine
, int osabi
, int abiversion
);
1691 Target_x86_64
* target_
;
1694 // Recognize an x86_64 object file when we already know that the machine
1695 // number is EM_X86_64.
1698 Target_selector_x86_64::recognize(int, int, int)
1700 if (this->target_
== NULL
)
1701 this->target_
= new Target_x86_64();
1702 return this->target_
;
1705 Target_selector_x86_64 target_selector_x86_64
;
1707 } // End anonymous namespace.