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 Output_section
* output_section
,
87 bool needs_special_offset_handling
,
88 size_t local_symbol_count
,
89 const unsigned char* plocal_symbols
);
91 // Finalize the sections.
93 do_finalize_sections(Layout
*);
95 // Return the value to use for a dynamic which requires special
98 do_dynsym_value(const Symbol
*) const;
100 // Relocate a section.
102 relocate_section(const Relocate_info
<64, false>*,
103 unsigned int sh_type
,
104 const unsigned char* prelocs
,
106 Output_section
* output_section
,
107 bool needs_special_offset_handling
,
109 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
112 // Return a string used to fill a code section with nops.
114 do_code_fill(off_t length
);
116 // Return whether SYM is defined by the ABI.
118 do_is_defined_by_abi(Symbol
* sym
) const
119 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
121 // Return the size of the GOT section.
125 gold_assert(this->got_
!= NULL
);
126 return this->got_
->data_size();
130 // The class which scans relocations.
134 local(const General_options
& options
, Symbol_table
* symtab
,
135 Layout
* layout
, Target_x86_64
* target
,
136 Sized_relobj
<64, false>* object
,
137 unsigned int data_shndx
,
138 Output_section
* output_section
,
139 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
140 const elfcpp::Sym
<64, false>& lsym
);
143 global(const General_options
& options
, Symbol_table
* symtab
,
144 Layout
* layout
, Target_x86_64
* target
,
145 Sized_relobj
<64, false>* object
,
146 unsigned int data_shndx
,
147 Output_section
* output_section
,
148 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
152 unsupported_reloc_local(Sized_relobj
<64, false>*, unsigned int r_type
);
155 unsupported_reloc_global(Sized_relobj
<64, false>*, unsigned int r_type
,
159 // The class which implements relocation.
164 : skip_call_tls_get_addr_(false)
169 if (this->skip_call_tls_get_addr_
)
171 // FIXME: This needs to specify the location somehow.
172 gold_error(_("missing expected TLS relocation"));
176 // Do a relocation. Return false if the caller should not issue
177 // any warnings about this relocation.
179 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, size_t relnum
,
180 const elfcpp::Rela
<64, false>&,
181 unsigned int r_type
, const Sized_symbol
<64>*,
182 const Symbol_value
<64>*,
183 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
187 // Do a TLS relocation.
189 relocate_tls(const Relocate_info
<64, false>*, Target_x86_64
*,
190 size_t relnum
, const elfcpp::Rela
<64, false>&,
191 unsigned int r_type
, const Sized_symbol
<64>*,
192 const Symbol_value
<64>*,
193 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
, off_t
);
195 // Do a TLS General-Dynamic to Local-Exec transition.
197 tls_gd_to_ie(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 // Do a TLS General-Dynamic to Local-Exec transition.
206 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
207 Output_segment
* tls_segment
,
208 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
209 elfcpp::Elf_types
<64>::Elf_Addr value
,
213 // Do a TLS Local-Dynamic to Local-Exec transition.
215 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
216 Output_segment
* tls_segment
,
217 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
218 elfcpp::Elf_types
<64>::Elf_Addr value
,
222 // Do a TLS Initial-Exec to Local-Exec transition.
224 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
225 Output_segment
* tls_segment
,
226 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
227 elfcpp::Elf_types
<64>::Elf_Addr value
,
231 // This is set if we should skip the next reloc, which should be a
232 // PLT32 reloc against ___tls_get_addr.
233 bool skip_call_tls_get_addr_
;
236 // Adjust TLS relocation type based on the options and whether this
237 // is a local symbol.
238 static tls::Tls_optimization
239 optimize_tls_reloc(bool is_final
, int r_type
);
241 // Get the GOT section, creating it if necessary.
242 Output_data_got
<64, false>*
243 got_section(Symbol_table
*, Layout
*);
245 // Get the GOT PLT section.
247 got_plt_section() const
249 gold_assert(this->got_plt_
!= NULL
);
250 return this->got_plt_
;
253 // Create a PLT entry for a global symbol.
255 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
257 // Get the PLT section.
258 Output_data_plt_x86_64
*
261 gold_assert(this->plt_
!= NULL
);
265 // Get the dynamic reloc section, creating it if necessary.
267 rela_dyn_section(Layout
*);
269 // Return true if the symbol may need a COPY relocation.
270 // References from an executable object to non-function symbols
271 // defined in a dynamic object may need a COPY relocation.
273 may_need_copy_reloc(Symbol
* gsym
)
275 return (!parameters
->output_is_shared()
276 && gsym
->is_from_dynobj()
277 && gsym
->type() != elfcpp::STT_FUNC
);
280 // Copy a relocation against a global symbol.
282 copy_reloc(const General_options
*, Symbol_table
*, Layout
*,
283 Sized_relobj
<64, false>*, unsigned int,
284 Output_section
*, Symbol
*, const elfcpp::Rela
<64, false>&);
286 // Information about this specific target which we pass to the
287 // general Target structure.
288 static const Target::Target_info x86_64_info
;
291 Output_data_got
<64, false>* got_
;
293 Output_data_plt_x86_64
* plt_
;
294 // The GOT PLT section.
295 Output_data_space
* got_plt_
;
296 // The dynamic reloc section.
297 Reloc_section
* rela_dyn_
;
298 // Relocs saved to avoid a COPY reloc.
299 Copy_relocs
<64, false>* copy_relocs_
;
300 // Space for variables copied with a COPY reloc.
301 Output_data_space
* dynbss_
;
304 const Target::Target_info
Target_x86_64::x86_64_info
=
307 false, // is_big_endian
308 elfcpp::EM_X86_64
, // machine_code
309 false, // has_make_symbol
310 false, // has_resolve
311 true, // has_code_fill
312 true, // is_default_stack_executable
313 "/lib/ld64.so.1", // program interpreter
314 0x400000, // default_text_segment_address
315 0x1000, // abi_pagesize
316 0x1000 // common_pagesize
319 // Get the GOT section, creating it if necessary.
321 Output_data_got
<64, false>*
322 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
324 if (this->got_
== NULL
)
326 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
328 this->got_
= new Output_data_got
<64, false>();
330 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
331 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
334 // The old GNU linker creates a .got.plt section. We just
335 // create another set of data in the .got section. Note that we
336 // always create a PLT if we create a GOT, although the PLT
338 this->got_plt_
= new Output_data_space(8);
339 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
340 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
343 // The first three entries are reserved.
344 this->got_plt_
->set_current_data_size(3 * 8);
346 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
347 symtab
->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL
,
349 0, 0, elfcpp::STT_OBJECT
,
351 elfcpp::STV_HIDDEN
, 0,
358 // Get the dynamic reloc section, creating it if necessary.
360 Target_x86_64::Reloc_section
*
361 Target_x86_64::rela_dyn_section(Layout
* layout
)
363 if (this->rela_dyn_
== NULL
)
365 gold_assert(layout
!= NULL
);
366 this->rela_dyn_
= new Reloc_section();
367 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
368 elfcpp::SHF_ALLOC
, this->rela_dyn_
);
370 return this->rela_dyn_
;
373 // A class to handle the PLT data.
375 class Output_data_plt_x86_64
: public Output_section_data
378 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
380 Output_data_plt_x86_64(Layout
*, Output_data_space
*);
382 // Add an entry to the PLT.
384 add_entry(Symbol
* gsym
);
386 // Return the .rel.plt section data.
389 { return this->rel_
; }
393 do_adjust_output_section(Output_section
* os
);
396 // The size of an entry in the PLT.
397 static const int plt_entry_size
= 16;
399 // The first entry in the PLT.
400 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
401 // procedure linkage table for both programs and shared objects."
402 static unsigned char first_plt_entry
[plt_entry_size
];
404 // Other entries in the PLT for an executable.
405 static unsigned char plt_entry
[plt_entry_size
];
407 // Set the final size.
409 set_final_data_size()
410 { this->set_data_size((this->count_
+ 1) * plt_entry_size
); }
412 // Write out the PLT data.
414 do_write(Output_file
*);
416 // The reloc section.
418 // The .got.plt section.
419 Output_data_space
* got_plt_
;
420 // The number of PLT entries.
424 // Create the PLT section. The ordinary .got section is an argument,
425 // since we need to refer to the start. We also create our own .got
426 // section just for PLT entries.
428 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout
* layout
,
429 Output_data_space
* got_plt
)
430 : Output_section_data(8), got_plt_(got_plt
), count_(0)
432 this->rel_
= new Reloc_section();
433 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
434 elfcpp::SHF_ALLOC
, this->rel_
);
438 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
440 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
441 // linker, and so do we.
445 // Add an entry to the PLT.
448 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
450 gold_assert(!gsym
->has_plt_offset());
452 // Note that when setting the PLT offset we skip the initial
453 // reserved PLT entry.
454 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
458 off_t got_offset
= this->got_plt_
->current_data_size();
460 // Every PLT entry needs a GOT entry which points back to the PLT
461 // entry (this will be changed by the dynamic linker, normally
462 // lazily when the function is called).
463 this->got_plt_
->set_current_data_size(got_offset
+ 8);
465 // Every PLT entry needs a reloc.
466 gsym
->set_needs_dynsym_entry();
467 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
470 // Note that we don't need to save the symbol. The contents of the
471 // PLT are independent of which symbols are used. The symbols only
472 // appear in the relocations.
475 // The first entry in the PLT for an executable.
477 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
479 // From AMD64 ABI Draft 0.98, page 76
480 0xff, 0x35, // pushq contents of memory address
481 0, 0, 0, 0, // replaced with address of .got + 4
482 0xff, 0x25, // jmp indirect
483 0, 0, 0, 0, // replaced with address of .got + 8
484 0x90, 0x90, 0x90, 0x90 // noop (x4)
487 // Subsequent entries in the PLT for an executable.
489 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
491 // From AMD64 ABI Draft 0.98, page 76
492 0xff, 0x25, // jmpq indirect
493 0, 0, 0, 0, // replaced with address of symbol in .got
494 0x68, // pushq immediate
495 0, 0, 0, 0, // replaced with offset into relocation table
496 0xe9, // jmpq relative
497 0, 0, 0, 0 // replaced with offset to start of .plt
500 // Write out the PLT. This uses the hand-coded instructions above,
501 // and adjusts them as needed. This is specified by the AMD64 ABI.
504 Output_data_plt_x86_64::do_write(Output_file
* of
)
506 const off_t offset
= this->offset();
507 const off_t oview_size
= this->data_size();
508 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
510 const off_t got_file_offset
= this->got_plt_
->offset();
511 const off_t got_size
= this->got_plt_
->data_size();
512 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
515 unsigned char* pov
= oview
;
517 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
518 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
520 memcpy(pov
, first_plt_entry
, plt_entry_size
);
521 if (!parameters
->output_is_shared())
523 // We do a jmp relative to the PC at the end of this instruction.
524 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 8
525 - (plt_address
+ 6));
526 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 16
527 - (plt_address
+ 12));
529 pov
+= plt_entry_size
;
531 unsigned char* got_pov
= got_view
;
533 memset(got_pov
, 0, 24);
536 unsigned int plt_offset
= plt_entry_size
;
537 unsigned int got_offset
= 24;
538 const unsigned int count
= this->count_
;
539 for (unsigned int plt_index
= 0;
542 pov
+= plt_entry_size
,
544 plt_offset
+= plt_entry_size
,
547 // Set and adjust the PLT entry itself.
548 memcpy(pov
, plt_entry
, plt_entry_size
);
549 if (parameters
->output_is_shared())
550 // FIXME(csilvers): what's the right thing to write here?
551 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
553 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
554 (got_address
+ got_offset
555 - (plt_address
+ plt_offset
558 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
559 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
560 - (plt_offset
+ plt_entry_size
));
562 // Set the entry in the GOT.
563 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
566 gold_assert(pov
- oview
== oview_size
);
567 gold_assert(got_pov
- got_view
== got_size
);
569 of
->write_output_view(offset
, oview_size
, oview
);
570 of
->write_output_view(got_file_offset
, got_size
, got_view
);
573 // Create a PLT entry for a global symbol.
576 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
579 if (gsym
->has_plt_offset())
582 if (this->plt_
== NULL
)
584 // Create the GOT sections first.
585 this->got_section(symtab
, layout
);
587 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_plt_
);
588 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
590 | elfcpp::SHF_EXECINSTR
),
594 this->plt_
->add_entry(gsym
);
597 // Handle a relocation against a non-function symbol defined in a
598 // dynamic object. The traditional way to handle this is to generate
599 // a COPY relocation to copy the variable at runtime from the shared
600 // object into the executable's data segment. However, this is
601 // undesirable in general, as if the size of the object changes in the
602 // dynamic object, the executable will no longer work correctly. If
603 // this relocation is in a writable section, then we can create a
604 // dynamic reloc and the dynamic linker will resolve it to the correct
605 // address at runtime. However, we do not want do that if the
606 // relocation is in a read-only section, as it would prevent the
607 // readonly segment from being shared. And if we have to eventually
608 // generate a COPY reloc, then any dynamic relocations will be
609 // useless. So this means that if this is a writable section, we need
610 // to save the relocation until we see whether we have to create a
611 // COPY relocation for this symbol for any other relocation.
614 Target_x86_64::copy_reloc(const General_options
* options
,
615 Symbol_table
* symtab
,
617 Sized_relobj
<64, false>* object
,
618 unsigned int data_shndx
,
619 Output_section
* output_section
,
621 const elfcpp::Rela
<64, false>& rela
)
623 Sized_symbol
<64>* ssym
;
624 ssym
= symtab
->get_sized_symbol
SELECT_SIZE_NAME(64) (gsym
627 if (!Copy_relocs
<64, false>::need_copy_reloc(options
, object
,
630 // So far we do not need a COPY reloc. Save this relocation.
631 // If it turns out that we never need a COPY reloc for this
632 // symbol, then we will emit the relocation.
633 if (this->copy_relocs_
== NULL
)
634 this->copy_relocs_
= new Copy_relocs
<64, false>();
635 this->copy_relocs_
->save(ssym
, object
, data_shndx
, output_section
, rela
);
639 // Allocate space for this symbol in the .bss section.
641 elfcpp::Elf_types
<64>::Elf_WXword symsize
= ssym
->symsize();
643 // There is no defined way to determine the required alignment
644 // of the symbol. We pick the alignment based on the size. We
645 // set an arbitrary maximum of 256.
647 for (align
= 1; align
< 512; align
<<= 1)
648 if ((symsize
& align
) != 0)
651 if (this->dynbss_
== NULL
)
653 this->dynbss_
= new Output_data_space(align
);
654 layout
->add_output_section_data(".bss",
657 | elfcpp::SHF_WRITE
),
661 Output_data_space
* dynbss
= this->dynbss_
;
663 if (align
> dynbss
->addralign())
664 dynbss
->set_space_alignment(align
);
666 off_t dynbss_size
= dynbss
->current_data_size();
667 dynbss_size
= align_address(dynbss_size
, align
);
668 off_t offset
= dynbss_size
;
669 dynbss
->set_current_data_size(dynbss_size
+ symsize
);
671 symtab
->define_with_copy_reloc(this, ssym
, dynbss
, offset
);
673 // Add the COPY reloc.
674 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
675 rela_dyn
->add_global(ssym
, elfcpp::R_X86_64_COPY
, dynbss
, offset
, 0);
680 // Optimize the TLS relocation type based on what we know about the
681 // symbol. IS_FINAL is true if the final address of this symbol is
682 // known at link time.
684 tls::Tls_optimization
685 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
687 // If we are generating a shared library, then we can't do anything
689 if (parameters
->output_is_shared())
690 return tls::TLSOPT_NONE
;
694 case elfcpp::R_X86_64_TLSGD
:
695 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
696 case elfcpp::R_X86_64_TLSDESC_CALL
:
697 // These are General-Dynamic which permits fully general TLS
698 // access. Since we know that we are generating an executable,
699 // we can convert this to Initial-Exec. If we also know that
700 // this is a local symbol, we can further switch to Local-Exec.
702 return tls::TLSOPT_TO_LE
;
703 return tls::TLSOPT_TO_IE
;
705 case elfcpp::R_X86_64_TLSLD
:
706 // This is Local-Dynamic, which refers to a local symbol in the
707 // dynamic TLS block. Since we know that we generating an
708 // executable, we can switch to Local-Exec.
709 return tls::TLSOPT_TO_LE
;
711 case elfcpp::R_X86_64_DTPOFF32
:
712 case elfcpp::R_X86_64_DTPOFF64
:
713 // Another Local-Dynamic reloc.
714 return tls::TLSOPT_TO_LE
;
716 case elfcpp::R_X86_64_GOTTPOFF
:
717 // These are Initial-Exec relocs which get the thread offset
718 // from the GOT. If we know that we are linking against the
719 // local symbol, we can switch to Local-Exec, which links the
720 // thread offset into the instruction.
722 return tls::TLSOPT_TO_LE
;
723 return tls::TLSOPT_NONE
;
725 case elfcpp::R_X86_64_TPOFF32
:
726 // When we already have Local-Exec, there is nothing further we
728 return tls::TLSOPT_NONE
;
735 // Report an unsupported relocation against a local symbol.
738 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
741 gold_error(_("%s: unsupported reloc %u against local symbol"),
742 object
->name().c_str(), r_type
);
745 // Scan a relocation for a local symbol.
748 Target_x86_64::Scan::local(const General_options
&,
749 Symbol_table
* symtab
,
751 Target_x86_64
* target
,
752 Sized_relobj
<64, false>* object
,
753 unsigned int data_shndx
,
754 Output_section
* output_section
,
755 const elfcpp::Rela
<64, false>& reloc
,
757 const elfcpp::Sym
<64, false>& lsym
)
761 case elfcpp::R_X86_64_NONE
:
762 case elfcpp::R_386_GNU_VTINHERIT
:
763 case elfcpp::R_386_GNU_VTENTRY
:
766 case elfcpp::R_X86_64_64
:
767 // If building a shared library (or a position-independent
768 // executable), we need to create a dynamic relocation for
769 // this location. The relocation applied at link time will
770 // apply the link-time value, so we flag the location with
771 // an R_386_RELATIVE relocation so the dynamic loader can
772 // relocate it easily.
773 if (parameters
->output_is_position_independent())
775 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
776 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
777 output_section
, data_shndx
,
778 reloc
.get_r_offset(), 0);
782 case elfcpp::R_X86_64_32
:
783 case elfcpp::R_X86_64_32S
:
784 case elfcpp::R_X86_64_16
:
785 case elfcpp::R_X86_64_8
:
786 // If building a shared library (or a position-independent
787 // executable), we need to create a dynamic relocation for
788 // this location. The relocation applied at link time will
789 // apply the link-time value, so we flag the location with
790 // an R_386_RELATIVE relocation so the dynamic loader can
791 // relocate it easily.
792 if (parameters
->output_is_position_independent())
794 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
795 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
796 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
797 data_shndx
, reloc
.get_r_offset(),
798 reloc
.get_r_addend());
802 case elfcpp::R_X86_64_PC64
:
803 case elfcpp::R_X86_64_PC32
:
804 case elfcpp::R_X86_64_PC16
:
805 case elfcpp::R_X86_64_PC8
:
808 case elfcpp::R_X86_64_PLT32
:
809 // Since we know this is a local symbol, we can handle this as a
813 case elfcpp::R_X86_64_GOTPC32
:
814 case elfcpp::R_X86_64_GOTOFF64
:
815 case elfcpp::R_X86_64_GOTPC64
:
816 case elfcpp::R_X86_64_PLTOFF64
:
817 // We need a GOT section.
818 target
->got_section(symtab
, layout
);
819 // For PLTOFF64, we'd normally want a PLT section, but since we
820 // know this is a local symbol, no PLT is needed.
823 case elfcpp::R_X86_64_GOT64
:
824 case elfcpp::R_X86_64_GOT32
:
825 case elfcpp::R_X86_64_GOTPCREL64
:
826 case elfcpp::R_X86_64_GOTPCREL
:
827 case elfcpp::R_X86_64_GOTPLT64
:
829 // The symbol requires a GOT entry.
830 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
831 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
832 if (got
->add_local(object
, r_sym
))
834 // If we are generating a shared object, we need to add a
835 // dynamic relocation for this symbol's GOT entry.
836 if (parameters
->output_is_position_independent())
838 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
839 // R_X86_64_RELATIVE assumes a 64-bit relocation.
840 if (r_type
!= elfcpp::R_X86_64_GOT32
)
841 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
842 got
, object
->local_got_offset(r_sym
), 0);
844 rela_dyn
->add_local(object
, r_sym
, r_type
,
845 got
, object
->local_got_offset(r_sym
), 0);
848 // For GOTPLT64, we'd normally want a PLT section, but since
849 // we know this is a local symbol, no PLT is needed.
853 case elfcpp::R_X86_64_COPY
:
854 case elfcpp::R_X86_64_GLOB_DAT
:
855 case elfcpp::R_X86_64_JUMP_SLOT
:
856 case elfcpp::R_X86_64_RELATIVE
:
857 // These are outstanding tls relocs, which are unexpected when linking
858 case elfcpp::R_X86_64_TPOFF64
:
859 case elfcpp::R_X86_64_DTPMOD64
:
860 case elfcpp::R_X86_64_TLSDESC
:
861 gold_error(_("%s: unexpected reloc %u in object file"),
862 object
->name().c_str(), r_type
);
865 // These are initial tls relocs, which are expected when linking
866 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
867 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
868 case elfcpp::R_X86_64_TLSDESC_CALL
:
869 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
870 case elfcpp::R_X86_64_DTPOFF32
:
871 case elfcpp::R_X86_64_DTPOFF64
:
872 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
873 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
875 bool output_is_shared
= parameters
->output_is_shared();
876 const tls::Tls_optimization optimized_type
877 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
880 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
881 if (optimized_type
== tls::TLSOPT_NONE
)
883 // Create a pair of GOT entries for the module index and
884 // dtv-relative offset.
885 Output_data_got
<64, false>* got
886 = target
->got_section(symtab
, layout
);
887 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
888 got
->add_local_tls_with_rela(object
, r_sym
,
889 lsym
.get_st_shndx(), true,
890 target
->rela_dyn_section(layout
),
891 elfcpp::R_X86_64_DTPMOD64
);
893 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
894 unsupported_reloc_local(object
, r_type
);
897 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
898 case elfcpp::R_X86_64_TLSDESC_CALL
:
899 // FIXME: If not relaxing to LE, we need to generate
900 // a GOT entry with a R_x86_64_TLSDESC reloc.
901 if (optimized_type
!= tls::TLSOPT_TO_LE
)
902 unsupported_reloc_local(object
, r_type
);
905 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
906 if (optimized_type
== tls::TLSOPT_NONE
)
908 // Create a GOT entry for the module index.
909 Output_data_got
<64, false>* got
910 = target
->got_section(symtab
, layout
);
911 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
912 got
->add_local_tls_with_rela(object
, r_sym
,
913 lsym
.get_st_shndx(), false,
914 target
->rela_dyn_section(layout
),
915 elfcpp::R_X86_64_DTPMOD64
);
917 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
918 unsupported_reloc_local(object
, r_type
);
921 case elfcpp::R_X86_64_DTPOFF32
:
922 case elfcpp::R_X86_64_DTPOFF64
:
925 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
926 if (optimized_type
== tls::TLSOPT_NONE
)
928 // Create a GOT entry for the tp-relative offset.
929 Output_data_got
<64, false>* got
930 = target
->got_section(symtab
, layout
);
931 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
932 got
->add_local_with_rela(object
, r_sym
,
933 target
->rela_dyn_section(layout
),
934 elfcpp::R_X86_64_TPOFF64
);
936 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
937 unsupported_reloc_local(object
, r_type
);
940 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
941 if (output_is_shared
)
942 unsupported_reloc_local(object
, r_type
);
951 case elfcpp::R_X86_64_SIZE32
:
952 case elfcpp::R_X86_64_SIZE64
:
954 gold_error(_("%s: unsupported reloc %u against local symbol"),
955 object
->name().c_str(), r_type
);
961 // Report an unsupported relocation against a global symbol.
964 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
968 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
969 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
972 // Scan a relocation for a global symbol.
975 Target_x86_64::Scan::global(const General_options
& options
,
976 Symbol_table
* symtab
,
978 Target_x86_64
* target
,
979 Sized_relobj
<64, false>* object
,
980 unsigned int data_shndx
,
981 Output_section
* output_section
,
982 const elfcpp::Rela
<64, false>& reloc
,
988 case elfcpp::R_X86_64_NONE
:
989 case elfcpp::R_386_GNU_VTINHERIT
:
990 case elfcpp::R_386_GNU_VTENTRY
:
993 case elfcpp::R_X86_64_64
:
994 case elfcpp::R_X86_64_32
:
995 case elfcpp::R_X86_64_32S
:
996 case elfcpp::R_X86_64_16
:
997 case elfcpp::R_X86_64_8
:
999 // Make a PLT entry if necessary.
1000 if (gsym
->needs_plt_entry())
1002 target
->make_plt_entry(symtab
, layout
, gsym
);
1003 // Since this is not a PC-relative relocation, we may be
1004 // taking the address of a function. In that case we need to
1005 // set the entry in the dynamic symbol table to the address of
1007 if (gsym
->is_from_dynobj())
1008 gsym
->set_needs_dynsym_value();
1010 // Make a dynamic relocation if necessary.
1011 if (gsym
->needs_dynamic_reloc(true, false))
1013 if (target
->may_need_copy_reloc(gsym
))
1015 target
->copy_reloc(&options
, symtab
, layout
, object
,
1016 data_shndx
, output_section
, gsym
, reloc
);
1018 else if (r_type
== elfcpp::R_X86_64_64
1019 && gsym
->can_use_relative_reloc(false))
1021 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1022 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
1023 output_section
, data_shndx
,
1024 reloc
.get_r_offset(), 0);
1028 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1029 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1030 data_shndx
, reloc
.get_r_offset(),
1031 reloc
.get_r_addend());
1037 case elfcpp::R_X86_64_PC64
:
1038 case elfcpp::R_X86_64_PC32
:
1039 case elfcpp::R_X86_64_PC16
:
1040 case elfcpp::R_X86_64_PC8
:
1042 // Make a PLT entry if necessary.
1043 if (gsym
->needs_plt_entry())
1044 target
->make_plt_entry(symtab
, layout
, gsym
);
1045 // Make a dynamic relocation if necessary.
1046 bool is_function_call
= (gsym
->type() == elfcpp::STT_FUNC
);
1047 if (gsym
->needs_dynamic_reloc(true, is_function_call
))
1049 if (target
->may_need_copy_reloc(gsym
))
1051 target
->copy_reloc(&options
, symtab
, layout
, object
,
1052 data_shndx
, output_section
, gsym
, reloc
);
1056 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1057 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1058 data_shndx
, reloc
.get_r_offset(),
1059 reloc
.get_r_addend());
1065 case elfcpp::R_X86_64_GOT64
:
1066 case elfcpp::R_X86_64_GOT32
:
1067 case elfcpp::R_X86_64_GOTPCREL64
:
1068 case elfcpp::R_X86_64_GOTPCREL
:
1069 case elfcpp::R_X86_64_GOTPLT64
:
1071 // The symbol requires a GOT entry.
1072 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1073 if (gsym
->final_value_is_known())
1074 got
->add_global(gsym
);
1077 // If this symbol is not fully resolved, we need to add a
1078 // dynamic relocation for it.
1079 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1080 if (gsym
->is_from_dynobj() || gsym
->is_preemptible())
1081 got
->add_global_with_rela(gsym
, rela_dyn
,
1082 elfcpp::R_X86_64_GLOB_DAT
);
1085 if (got
->add_global(gsym
))
1087 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_RELATIVE
,
1088 got
, gsym
->got_offset(), 0);
1089 // Make sure we write the link-time value to the GOT.
1090 gsym
->set_needs_value_in_got();
1094 // For GOTPLT64, we also need a PLT entry (but only if the
1095 // symbol is not fully resolved).
1096 if (r_type
== elfcpp::R_X86_64_GOTPLT64
1097 && !gsym
->final_value_is_known())
1098 target
->make_plt_entry(symtab
, layout
, gsym
);
1102 case elfcpp::R_X86_64_PLT32
:
1103 // If the symbol is fully resolved, this is just a PC32 reloc.
1104 // Otherwise we need a PLT entry.
1105 if (gsym
->final_value_is_known())
1107 // If building a shared library, we can also skip the PLT entry
1108 // if the symbol is defined in the output file and is protected
1110 if (gsym
->is_defined()
1111 && !gsym
->is_from_dynobj()
1112 && !gsym
->is_preemptible())
1114 target
->make_plt_entry(symtab
, layout
, gsym
);
1117 case elfcpp::R_X86_64_GOTPC32
:
1118 case elfcpp::R_X86_64_GOTOFF64
:
1119 case elfcpp::R_X86_64_GOTPC64
:
1120 case elfcpp::R_X86_64_PLTOFF64
:
1121 // We need a GOT section.
1122 target
->got_section(symtab
, layout
);
1123 // For PLTOFF64, we also need a PLT entry (but only if the
1124 // symbol is not fully resolved).
1125 if (r_type
== elfcpp::R_X86_64_PLTOFF64
1126 && !gsym
->final_value_is_known())
1127 target
->make_plt_entry(symtab
, layout
, gsym
);
1130 case elfcpp::R_X86_64_COPY
:
1131 case elfcpp::R_X86_64_GLOB_DAT
:
1132 case elfcpp::R_X86_64_JUMP_SLOT
:
1133 case elfcpp::R_X86_64_RELATIVE
:
1134 // These are outstanding tls relocs, which are unexpected when linking
1135 case elfcpp::R_X86_64_TPOFF64
:
1136 case elfcpp::R_X86_64_DTPMOD64
:
1137 case elfcpp::R_X86_64_TLSDESC
:
1138 gold_error(_("%s: unexpected reloc %u in object file"),
1139 object
->name().c_str(), r_type
);
1142 // These are initial tls relocs, which are expected for global()
1143 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1144 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1145 case elfcpp::R_X86_64_TLSDESC_CALL
:
1146 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1147 case elfcpp::R_X86_64_DTPOFF32
:
1148 case elfcpp::R_X86_64_DTPOFF64
:
1149 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1150 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1152 const bool is_final
= gsym
->final_value_is_known();
1153 const tls::Tls_optimization optimized_type
1154 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1157 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1158 if (optimized_type
== tls::TLSOPT_NONE
)
1160 // Create a pair of GOT entries for the module index and
1161 // dtv-relative offset.
1162 Output_data_got
<64, false>* got
1163 = target
->got_section(symtab
, layout
);
1164 got
->add_global_tls_with_rela(gsym
,
1165 target
->rela_dyn_section(layout
),
1166 elfcpp::R_X86_64_DTPMOD64
,
1167 elfcpp::R_X86_64_DTPOFF64
);
1169 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1171 // Create a GOT entry for the tp-relative offset.
1172 Output_data_got
<64, false>* got
1173 = target
->got_section(symtab
, layout
);
1174 got
->add_global_with_rela(gsym
,
1175 target
->rela_dyn_section(layout
),
1176 elfcpp::R_X86_64_TPOFF64
);
1178 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1179 unsupported_reloc_global(object
, r_type
, gsym
);
1182 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1183 case elfcpp::R_X86_64_TLSDESC_CALL
:
1184 // FIXME: If not relaxing to LE, we need to generate
1185 // DTPMOD64 and DTPOFF64, or TLSDESC, relocs.
1186 if (optimized_type
!= tls::TLSOPT_TO_LE
)
1187 unsupported_reloc_global(object
, r_type
, gsym
);
1190 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1191 if (optimized_type
== tls::TLSOPT_NONE
)
1193 // Create a GOT entry for the module index.
1194 Output_data_got
<64, false>* got
1195 = target
->got_section(symtab
, layout
);
1196 got
->add_global_tls_with_rela(gsym
,
1197 target
->rela_dyn_section(layout
),
1198 elfcpp::R_X86_64_DTPMOD64
);
1200 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1201 unsupported_reloc_global(object
, r_type
, gsym
);
1204 case elfcpp::R_X86_64_DTPOFF32
:
1205 case elfcpp::R_X86_64_DTPOFF64
:
1208 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1209 if (optimized_type
== tls::TLSOPT_NONE
)
1211 // Create a GOT entry for the tp-relative offset.
1212 Output_data_got
<64, false>* got
1213 = target
->got_section(symtab
, layout
);
1214 got
->add_global_with_rela(gsym
,
1215 target
->rela_dyn_section(layout
),
1216 elfcpp::R_X86_64_TPOFF64
);
1218 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1219 unsupported_reloc_global(object
, r_type
, gsym
);
1222 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1223 if (parameters
->output_is_shared())
1224 unsupported_reloc_local(object
, r_type
);
1233 case elfcpp::R_X86_64_SIZE32
:
1234 case elfcpp::R_X86_64_SIZE64
:
1236 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1237 object
->name().c_str(), r_type
,
1238 gsym
->demangled_name().c_str());
1243 // Scan relocations for a section.
1246 Target_x86_64::scan_relocs(const General_options
& options
,
1247 Symbol_table
* symtab
,
1249 Sized_relobj
<64, false>* object
,
1250 unsigned int data_shndx
,
1251 unsigned int sh_type
,
1252 const unsigned char* prelocs
,
1254 Output_section
* output_section
,
1255 bool needs_special_offset_handling
,
1256 size_t local_symbol_count
,
1257 const unsigned char* plocal_symbols
)
1259 if (sh_type
== elfcpp::SHT_REL
)
1261 gold_error(_("%s: unsupported REL reloc section"),
1262 object
->name().c_str());
1266 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1267 Target_x86_64::Scan
>(
1277 needs_special_offset_handling
,
1282 // Finalize the sections.
1285 Target_x86_64::do_finalize_sections(Layout
* layout
)
1287 // Fill in some more dynamic tags.
1288 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1291 if (this->got_plt_
!= NULL
)
1292 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
1294 if (this->plt_
!= NULL
)
1296 const Output_data
* od
= this->plt_
->rel_plt();
1297 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
1298 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
1299 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_RELA
);
1302 if (this->rela_dyn_
!= NULL
)
1304 const Output_data
* od
= this->rela_dyn_
;
1305 odyn
->add_section_address(elfcpp::DT_RELA
, od
);
1306 odyn
->add_section_size(elfcpp::DT_RELASZ
, od
);
1307 odyn
->add_constant(elfcpp::DT_RELAENT
,
1308 elfcpp::Elf_sizes
<64>::rela_size
);
1311 if (!parameters
->output_is_shared())
1313 // The value of the DT_DEBUG tag is filled in by the dynamic
1314 // linker at run time, and used by the debugger.
1315 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
1319 // Emit any relocs we saved in an attempt to avoid generating COPY
1321 if (this->copy_relocs_
== NULL
)
1323 if (this->copy_relocs_
->any_to_emit())
1325 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1326 this->copy_relocs_
->emit(rela_dyn
);
1328 delete this->copy_relocs_
;
1329 this->copy_relocs_
= NULL
;
1332 // Perform a relocation.
1335 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1336 Target_x86_64
* target
,
1338 const elfcpp::Rela
<64, false>& rela
,
1339 unsigned int r_type
,
1340 const Sized_symbol
<64>* gsym
,
1341 const Symbol_value
<64>* psymval
,
1342 unsigned char* view
,
1343 elfcpp::Elf_types
<64>::Elf_Addr address
,
1346 if (this->skip_call_tls_get_addr_
)
1348 if (r_type
!= elfcpp::R_X86_64_PLT32
1350 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1352 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1353 _("missing expected TLS relocation"));
1357 this->skip_call_tls_get_addr_
= false;
1362 // Pick the value to use for symbols defined in shared objects.
1363 Symbol_value
<64> symval
;
1365 && (gsym
->is_from_dynobj()
1366 || (parameters
->output_is_shared()
1367 && gsym
->is_preemptible()))
1368 && gsym
->has_plt_offset())
1370 symval
.set_output_value(target
->plt_section()->address()
1371 + gsym
->plt_offset());
1375 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1376 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1378 // Get the GOT offset if needed.
1379 // The GOT pointer points to the end of the GOT section.
1380 // We need to subtract the size of the GOT section to get
1381 // the actual offset to use in the relocation.
1382 bool have_got_offset
= false;
1383 unsigned int got_offset
= 0;
1386 case elfcpp::R_X86_64_GOT32
:
1387 case elfcpp::R_X86_64_GOT64
:
1388 case elfcpp::R_X86_64_GOTPLT64
:
1389 case elfcpp::R_X86_64_GOTPCREL
:
1390 case elfcpp::R_X86_64_GOTPCREL64
:
1393 gold_assert(gsym
->has_got_offset());
1394 got_offset
= gsym
->got_offset() - target
->got_size();
1398 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1399 gold_assert(object
->local_has_got_offset(r_sym
));
1400 got_offset
= object
->local_got_offset(r_sym
) - target
->got_size();
1402 have_got_offset
= true;
1411 case elfcpp::R_X86_64_NONE
:
1412 case elfcpp::R_386_GNU_VTINHERIT
:
1413 case elfcpp::R_386_GNU_VTENTRY
:
1416 case elfcpp::R_X86_64_64
:
1417 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1420 case elfcpp::R_X86_64_PC64
:
1421 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1425 case elfcpp::R_X86_64_32
:
1426 // FIXME: we need to verify that value + addend fits into 32 bits:
1427 // uint64_t x = value + addend;
1428 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1429 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1430 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1433 case elfcpp::R_X86_64_32S
:
1434 // FIXME: we need to verify that value + addend fits into 32 bits:
1435 // int64_t x = value + addend; // note this quantity is signed!
1436 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1437 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1440 case elfcpp::R_X86_64_PC32
:
1441 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1445 case elfcpp::R_X86_64_16
:
1446 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
1449 case elfcpp::R_X86_64_PC16
:
1450 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
1454 case elfcpp::R_X86_64_8
:
1455 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
1458 case elfcpp::R_X86_64_PC8
:
1459 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
1463 case elfcpp::R_X86_64_PLT32
:
1464 gold_assert(gsym
== NULL
1465 || gsym
->has_plt_offset()
1466 || gsym
->final_value_is_known());
1467 // Note: while this code looks the same as for R_X86_64_PC32, it
1468 // behaves differently because psymval was set to point to
1469 // the PLT entry, rather than the symbol, in Scan::global().
1470 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1474 case elfcpp::R_X86_64_PLTOFF64
:
1477 gold_assert(gsym
->has_plt_offset()
1478 || gsym
->final_value_is_known());
1479 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
1480 got_address
= target
->got_section(NULL
, NULL
)->address();
1481 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
1482 addend
- got_address
);
1485 case elfcpp::R_X86_64_GOT32
:
1486 gold_assert(have_got_offset
);
1487 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
1490 case elfcpp::R_X86_64_GOTPC32
:
1493 elfcpp::Elf_types
<64>::Elf_Addr value
;
1494 value
= target
->got_plt_section()->address();
1495 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1499 case elfcpp::R_X86_64_GOT64
:
1500 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1501 // Since we always add a PLT entry, this is equivalent.
1502 case elfcpp::R_X86_64_GOTPLT64
:
1503 gold_assert(have_got_offset
);
1504 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
1507 case elfcpp::R_X86_64_GOTPC64
:
1510 elfcpp::Elf_types
<64>::Elf_Addr value
;
1511 value
= target
->got_plt_section()->address();
1512 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1516 case elfcpp::R_X86_64_GOTOFF64
:
1518 elfcpp::Elf_types
<64>::Elf_Addr value
;
1519 value
= (psymval
->value(object
, 0)
1520 - target
->got_plt_section()->address());
1521 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
1525 case elfcpp::R_X86_64_GOTPCREL
:
1527 gold_assert(have_got_offset
);
1528 elfcpp::Elf_types
<64>::Elf_Addr value
;
1529 value
= target
->got_plt_section()->address() + got_offset
;
1530 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
1534 case elfcpp::R_X86_64_GOTPCREL64
:
1536 gold_assert(have_got_offset
);
1537 elfcpp::Elf_types
<64>::Elf_Addr value
;
1538 value
= target
->got_plt_section()->address() + got_offset
;
1539 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
1543 case elfcpp::R_X86_64_COPY
:
1544 case elfcpp::R_X86_64_GLOB_DAT
:
1545 case elfcpp::R_X86_64_JUMP_SLOT
:
1546 case elfcpp::R_X86_64_RELATIVE
:
1547 // These are outstanding tls relocs, which are unexpected when linking
1548 case elfcpp::R_X86_64_TPOFF64
:
1549 case elfcpp::R_X86_64_DTPMOD64
:
1550 case elfcpp::R_X86_64_TLSDESC
:
1551 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1552 _("unexpected reloc %u in object file"),
1556 // These are initial tls relocs, which are expected when linking
1557 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1558 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1559 case elfcpp::R_X86_64_TLSDESC_CALL
:
1560 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1561 case elfcpp::R_X86_64_DTPOFF32
:
1562 case elfcpp::R_X86_64_DTPOFF64
:
1563 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1564 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1565 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
1566 view
, address
, view_size
);
1569 case elfcpp::R_X86_64_SIZE32
:
1570 case elfcpp::R_X86_64_SIZE64
:
1572 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1573 _("unsupported reloc %u"),
1581 // Perform a TLS relocation.
1584 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
1585 Target_x86_64
* target
,
1587 const elfcpp::Rela
<64, false>& rela
,
1588 unsigned int r_type
,
1589 const Sized_symbol
<64>* gsym
,
1590 const Symbol_value
<64>* psymval
,
1591 unsigned char* view
,
1592 elfcpp::Elf_types
<64>::Elf_Addr
,
1595 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
1597 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1599 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
1601 const bool is_final
= (gsym
== NULL
1602 ? !parameters
->output_is_position_independent()
1603 : gsym
->final_value_is_known());
1604 const tls::Tls_optimization optimized_type
1605 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1608 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1609 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1610 case elfcpp::R_X86_64_TLSDESC_CALL
:
1611 if (optimized_type
== tls::TLSOPT_TO_LE
)
1613 gold_assert(tls_segment
!= NULL
);
1614 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
1615 rela
, r_type
, value
, view
,
1621 unsigned int got_offset
;
1624 gold_assert(gsym
->has_tls_got_offset(true));
1625 got_offset
= gsym
->tls_got_offset(true) - target
->got_size();
1629 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1630 gold_assert(object
->local_has_tls_got_offset(r_sym
, true));
1631 got_offset
= (object
->local_tls_got_offset(r_sym
, true)
1632 - target
->got_size());
1634 if (optimized_type
== tls::TLSOPT_TO_IE
)
1636 gold_assert(tls_segment
!= NULL
);
1637 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
1638 got_offset
, view
, view_size
);
1641 else if (optimized_type
== tls::TLSOPT_NONE
)
1643 // Relocate the field with the offset of the pair of GOT
1645 Relocate_functions
<64, false>::rel64(view
, got_offset
);
1649 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1650 _("unsupported reloc %u"), r_type
);
1653 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1654 if (optimized_type
== tls::TLSOPT_TO_LE
)
1656 gold_assert(tls_segment
!= NULL
);
1657 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
1658 value
, view
, view_size
);
1661 else if (optimized_type
== tls::TLSOPT_NONE
)
1663 // Relocate the field with the offset of the GOT entry for
1664 // the module index.
1665 unsigned int got_offset
;
1668 gold_assert(gsym
->has_tls_got_offset(false));
1669 got_offset
= gsym
->tls_got_offset(false) - target
->got_size();
1673 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1674 gold_assert(object
->local_has_tls_got_offset(r_sym
, false));
1675 got_offset
= (object
->local_tls_got_offset(r_sym
, false)
1676 - target
->got_size());
1678 Relocate_functions
<64, false>::rel64(view
, got_offset
);
1681 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1682 _("unsupported reloc %u"), r_type
);
1685 case elfcpp::R_X86_64_DTPOFF32
:
1686 gold_assert(tls_segment
!= NULL
);
1687 if (optimized_type
== tls::TLSOPT_TO_LE
)
1688 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1690 value
= value
- tls_segment
->vaddr();
1691 Relocate_functions
<64, false>::rel32(view
, value
);
1694 case elfcpp::R_X86_64_DTPOFF64
:
1695 gold_assert(tls_segment
!= NULL
);
1696 if (optimized_type
== tls::TLSOPT_TO_LE
)
1697 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1699 value
= value
- tls_segment
->vaddr();
1700 Relocate_functions
<64, false>::rel64(view
, value
);
1703 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1704 if (optimized_type
== tls::TLSOPT_TO_LE
)
1706 gold_assert(tls_segment
!= NULL
);
1707 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
1708 rela
, r_type
, value
, view
,
1712 else if (optimized_type
== tls::TLSOPT_NONE
)
1714 // Relocate the field with the offset of the GOT entry for
1715 // the tp-relative offset of the symbol.
1716 unsigned int got_offset
;
1719 gold_assert(gsym
->has_got_offset());
1720 got_offset
= gsym
->got_offset() - target
->got_size();
1724 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1725 gold_assert(object
->local_has_got_offset(r_sym
));
1726 got_offset
= (object
->local_got_offset(r_sym
)
1727 - target
->got_size());
1729 Relocate_functions
<64, false>::rel64(view
, got_offset
);
1732 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1733 _("unsupported reloc type %u"),
1737 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1738 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1739 Relocate_functions
<64, false>::rel32(view
, value
);
1744 // Do a relocation in which we convert a TLS General-Dynamic to an
1748 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info
<64, false>* relinfo
,
1750 Output_segment
* tls_segment
,
1751 const elfcpp::Rela
<64, false>& rela
,
1753 elfcpp::Elf_types
<64>::Elf_Addr value
,
1754 unsigned char* view
,
1757 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
1758 // .word 0x6666; rex64; call __tls_get_addr
1759 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
1761 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
1762 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
1764 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1765 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
1766 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1767 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
1769 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
1771 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1772 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
1774 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1776 this->skip_call_tls_get_addr_
= true;
1779 // Do a relocation in which we convert a TLS General-Dynamic to a
1783 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
1785 Output_segment
* tls_segment
,
1786 const elfcpp::Rela
<64, false>& rela
,
1788 elfcpp::Elf_types
<64>::Elf_Addr value
,
1789 unsigned char* view
,
1792 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
1793 // .word 0x6666; rex64; call __tls_get_addr
1794 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
1796 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
1797 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
1799 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1800 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
1801 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1802 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
1804 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
1806 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1807 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
1809 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1811 this->skip_call_tls_get_addr_
= true;
1815 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
1818 const elfcpp::Rela
<64, false>& rela
,
1820 elfcpp::Elf_types
<64>::Elf_Addr
,
1821 unsigned char* view
,
1824 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
1825 // ... leq foo@dtpoff(%rax),%reg
1826 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
1828 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
1829 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
1831 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
1832 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
1834 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
1836 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
1838 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1840 this->skip_call_tls_get_addr_
= true;
1843 // Do a relocation in which we convert a TLS Initial-Exec to a
1847 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
1849 Output_segment
* tls_segment
,
1850 const elfcpp::Rela
<64, false>& rela
,
1852 elfcpp::Elf_types
<64>::Elf_Addr value
,
1853 unsigned char* view
,
1856 // We need to examine the opcodes to figure out which instruction we
1859 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
1860 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
1862 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
1863 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
1865 unsigned char op1
= view
[-3];
1866 unsigned char op2
= view
[-2];
1867 unsigned char op3
= view
[-1];
1868 unsigned char reg
= op3
>> 3;
1876 view
[-1] = 0xc0 | reg
;
1880 // Special handling for %rsp.
1884 view
[-1] = 0xc0 | reg
;
1892 view
[-1] = 0x80 | reg
| (reg
<< 3);
1895 value
= value
- (tls_segment
->vaddr() + tls_segment
->memsz());
1896 Relocate_functions
<64, false>::rela32(view
, value
, 0);
1899 // Relocate section data.
1902 Target_x86_64::relocate_section(const Relocate_info
<64, false>* relinfo
,
1903 unsigned int sh_type
,
1904 const unsigned char* prelocs
,
1906 Output_section
* output_section
,
1907 bool needs_special_offset_handling
,
1908 unsigned char* view
,
1909 elfcpp::Elf_types
<64>::Elf_Addr address
,
1912 gold_assert(sh_type
== elfcpp::SHT_RELA
);
1914 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1915 Target_x86_64::Relocate
>(
1921 needs_special_offset_handling
,
1927 // Return the value to use for a dynamic which requires special
1928 // treatment. This is how we support equality comparisons of function
1929 // pointers across shared library boundaries, as described in the
1930 // processor specific ABI supplement.
1933 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
1935 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
1936 return this->plt_section()->address() + gsym
->plt_offset();
1939 // Return a string used to fill a code section with nops to take up
1940 // the specified length.
1943 Target_x86_64::do_code_fill(off_t length
)
1947 // Build a jmpq instruction to skip over the bytes.
1948 unsigned char jmp
[5];
1950 elfcpp::Swap_unaligned
<64, false>::writeval(jmp
+ 1, length
- 5);
1951 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
1952 + std::string(length
- 5, '\0'));
1955 // Nop sequences of various lengths.
1956 const char nop1
[1] = { 0x90 }; // nop
1957 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
1958 const char nop3
[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1959 const char nop4
[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1960 const char nop5
[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1961 0x00 }; // leal 0(%esi,1),%esi
1962 const char nop6
[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1964 const char nop7
[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1966 const char nop8
[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1967 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1968 const char nop9
[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1969 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1971 const char nop10
[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1972 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1974 const char nop11
[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1975 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1977 const char nop12
[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1978 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1979 0x00, 0x00, 0x00, 0x00 };
1980 const char nop13
[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1981 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1982 0x27, 0x00, 0x00, 0x00,
1984 const char nop14
[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1985 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1986 0xbc, 0x27, 0x00, 0x00,
1988 const char nop15
[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1989 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1990 0x90, 0x90, 0x90, 0x90,
1993 const char* nops
[16] = {
1995 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
1996 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
1999 return std::string(nops
[length
], length
);
2002 // The selector for x86_64 object files.
2004 class Target_selector_x86_64
: public Target_selector
2007 Target_selector_x86_64()
2008 : Target_selector(elfcpp::EM_X86_64
, 64, false)
2012 recognize(int machine
, int osabi
, int abiversion
);
2015 Target_x86_64
* target_
;
2018 // Recognize an x86_64 object file when we already know that the machine
2019 // number is EM_X86_64.
2022 Target_selector_x86_64::recognize(int, int, int)
2024 if (this->target_
== NULL
)
2025 this->target_
= new Target_x86_64();
2026 return this->target_
;
2029 Target_selector_x86_64 target_selector_x86_64
;
2031 } // End anonymous namespace.