1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009 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 modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
28 #include "parameters.h"
35 #include "copy-relocs.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
49 class Output_data_plt_x86_64
;
51 // The x86_64 target class.
53 // http://www.x86-64.org/documentation/abi.pdf
54 // TLS info comes from
55 // http://people.redhat.com/drepper/tls.pdf
56 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
58 class Target_x86_64
: public Target_freebsd
<64, false>
61 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
62 // uses only Elf64_Rela relocation entries with explicit addends."
63 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
66 : Target_freebsd
<64, false>(&x86_64_info
),
67 got_(NULL
), plt_(NULL
), got_plt_(NULL
), global_offset_table_(NULL
),
68 rela_dyn_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
), dynbss_(NULL
),
69 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
70 tls_base_symbol_defined_(false)
73 // This function should be defined in targets that can use relocation
74 // types to determine (implemented in local_reloc_may_be_function_pointer
75 // and global_reloc_may_be_function_pointer)
76 // if a function's pointer is taken. ICF uses this in safe mode to only
77 // fold those functions whose pointer is defintely not taken. For x86_64
78 // pie binaries, safe ICF cannot be done by looking at relocation types.
80 can_check_for_function_pointers() const
81 { return !parameters
->options().pie(); }
83 // Hook for a new output section.
85 do_new_output_section(Output_section
*) const;
87 // Scan the relocations to look for symbol adjustments.
89 gc_process_relocs(Symbol_table
* symtab
,
91 Sized_relobj
<64, false>* object
,
92 unsigned int data_shndx
,
94 const unsigned char* prelocs
,
96 Output_section
* output_section
,
97 bool needs_special_offset_handling
,
98 size_t local_symbol_count
,
99 const unsigned char* plocal_symbols
);
101 // Scan the relocations to look for symbol adjustments.
103 scan_relocs(Symbol_table
* symtab
,
105 Sized_relobj
<64, false>* object
,
106 unsigned int data_shndx
,
107 unsigned int sh_type
,
108 const unsigned char* prelocs
,
110 Output_section
* output_section
,
111 bool needs_special_offset_handling
,
112 size_t local_symbol_count
,
113 const unsigned char* plocal_symbols
);
115 // Finalize the sections.
117 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
119 // Return the value to use for a dynamic which requires special
122 do_dynsym_value(const Symbol
*) const;
124 // Relocate a section.
126 relocate_section(const Relocate_info
<64, false>*,
127 unsigned int sh_type
,
128 const unsigned char* prelocs
,
130 Output_section
* output_section
,
131 bool needs_special_offset_handling
,
133 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
134 section_size_type view_size
,
135 const Reloc_symbol_changes
*);
137 // Scan the relocs during a relocatable link.
139 scan_relocatable_relocs(Symbol_table
* symtab
,
141 Sized_relobj
<64, false>* object
,
142 unsigned int data_shndx
,
143 unsigned int sh_type
,
144 const unsigned char* prelocs
,
146 Output_section
* output_section
,
147 bool needs_special_offset_handling
,
148 size_t local_symbol_count
,
149 const unsigned char* plocal_symbols
,
150 Relocatable_relocs
*);
152 // Relocate a section during a relocatable link.
154 relocate_for_relocatable(const Relocate_info
<64, false>*,
155 unsigned int sh_type
,
156 const unsigned char* prelocs
,
158 Output_section
* output_section
,
159 off_t offset_in_output_section
,
160 const Relocatable_relocs
*,
162 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
163 section_size_type view_size
,
164 unsigned char* reloc_view
,
165 section_size_type reloc_view_size
);
167 // Return a string used to fill a code section with nops.
169 do_code_fill(section_size_type length
) const;
171 // Return whether SYM is defined by the ABI.
173 do_is_defined_by_abi(const Symbol
* sym
) const
174 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
176 // Return the symbol index to use for a target specific relocation.
177 // The only target specific relocation is R_X86_64_TLSDESC for a
178 // local symbol, which is an absolute reloc.
180 do_reloc_symbol_index(void*, unsigned int r_type
) const
182 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
186 // Return the addend to use for a target specific relocation.
188 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
190 // Adjust -fstack-split code which calls non-stack-split code.
192 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
193 section_offset_type fnoffset
, section_size_type fnsize
,
194 unsigned char* view
, section_size_type view_size
,
195 std::string
* from
, std::string
* to
) const;
197 // Return the size of the GOT section.
201 gold_assert(this->got_
!= NULL
);
202 return this->got_
->data_size();
205 // Add a new reloc argument, returning the index in the vector.
207 add_tlsdesc_info(Sized_relobj
<64, false>* object
, unsigned int r_sym
)
209 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
210 return this->tlsdesc_reloc_info_
.size() - 1;
214 // The class which scans relocations.
219 : issued_non_pic_error_(false)
223 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
224 Sized_relobj
<64, false>* object
,
225 unsigned int data_shndx
,
226 Output_section
* output_section
,
227 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
228 const elfcpp::Sym
<64, false>& lsym
);
231 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
232 Sized_relobj
<64, false>* object
,
233 unsigned int data_shndx
,
234 Output_section
* output_section
,
235 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
239 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
240 Target_x86_64
* target
,
241 Sized_relobj
<64, false>* object
,
242 unsigned int data_shndx
,
243 Output_section
* output_section
,
244 const elfcpp::Rela
<64, false>& reloc
,
246 const elfcpp::Sym
<64, false>& lsym
);
249 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
250 Target_x86_64
* target
,
251 Sized_relobj
<64, false>* object
,
252 unsigned int data_shndx
,
253 Output_section
* output_section
,
254 const elfcpp::Rela
<64, false>& reloc
,
260 unsupported_reloc_local(Sized_relobj
<64, false>*, unsigned int r_type
);
263 unsupported_reloc_global(Sized_relobj
<64, false>*, unsigned int r_type
,
267 check_non_pic(Relobj
*, unsigned int r_type
);
270 possible_function_pointer_reloc(unsigned int r_type
);
272 // Whether we have issued an error about a non-PIC compilation.
273 bool issued_non_pic_error_
;
276 // The class which implements relocation.
281 : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
286 if (this->skip_call_tls_get_addr_
)
288 // FIXME: This needs to specify the location somehow.
289 gold_error(_("missing expected TLS relocation"));
293 // Do a relocation. Return false if the caller should not issue
294 // any warnings about this relocation.
296 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, Output_section
*,
297 size_t relnum
, const elfcpp::Rela
<64, false>&,
298 unsigned int r_type
, const Sized_symbol
<64>*,
299 const Symbol_value
<64>*,
300 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
304 // Do a TLS relocation.
306 relocate_tls(const Relocate_info
<64, false>*, Target_x86_64
*,
307 size_t relnum
, const elfcpp::Rela
<64, false>&,
308 unsigned int r_type
, const Sized_symbol
<64>*,
309 const Symbol_value
<64>*,
310 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
313 // Do a TLS General-Dynamic to Initial-Exec transition.
315 tls_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
316 Output_segment
* tls_segment
,
317 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
318 elfcpp::Elf_types
<64>::Elf_Addr value
,
320 elfcpp::Elf_types
<64>::Elf_Addr
,
321 section_size_type view_size
);
323 // Do a TLS General-Dynamic to Local-Exec transition.
325 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
326 Output_segment
* tls_segment
,
327 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
328 elfcpp::Elf_types
<64>::Elf_Addr value
,
330 section_size_type view_size
);
332 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
334 tls_desc_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
335 Output_segment
* tls_segment
,
336 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
337 elfcpp::Elf_types
<64>::Elf_Addr value
,
339 elfcpp::Elf_types
<64>::Elf_Addr
,
340 section_size_type view_size
);
342 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
344 tls_desc_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
345 Output_segment
* tls_segment
,
346 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
347 elfcpp::Elf_types
<64>::Elf_Addr value
,
349 section_size_type view_size
);
351 // Do a TLS Local-Dynamic to Local-Exec transition.
353 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
354 Output_segment
* tls_segment
,
355 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
356 elfcpp::Elf_types
<64>::Elf_Addr value
,
358 section_size_type view_size
);
360 // Do a TLS Initial-Exec to Local-Exec transition.
362 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
363 Output_segment
* tls_segment
,
364 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
365 elfcpp::Elf_types
<64>::Elf_Addr value
,
367 section_size_type view_size
);
369 // This is set if we should skip the next reloc, which should be a
370 // PLT32 reloc against ___tls_get_addr.
371 bool skip_call_tls_get_addr_
;
373 // This is set if we see a relocation which could load the address
374 // of the TLS block. Whether we see such a relocation determines
375 // how we handle the R_X86_64_DTPOFF32 relocation, which is used
376 // in debugging sections.
377 bool saw_tls_block_reloc_
;
380 // A class which returns the size required for a relocation type,
381 // used while scanning relocs during a relocatable link.
382 class Relocatable_size_for_reloc
386 get_size_for_reloc(unsigned int, Relobj
*);
389 // Adjust TLS relocation type based on the options and whether this
390 // is a local symbol.
391 static tls::Tls_optimization
392 optimize_tls_reloc(bool is_final
, int r_type
);
394 // Get the GOT section, creating it if necessary.
395 Output_data_got
<64, false>*
396 got_section(Symbol_table
*, Layout
*);
398 // Get the GOT PLT section.
400 got_plt_section() const
402 gold_assert(this->got_plt_
!= NULL
);
403 return this->got_plt_
;
406 // Create the PLT section.
408 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
410 // Create a PLT entry for a global symbol.
412 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
414 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
416 define_tls_base_symbol(Symbol_table
*, Layout
*);
418 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
420 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
422 // Create a GOT entry for the TLS module index.
424 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
425 Sized_relobj
<64, false>* object
);
427 // Get the PLT section.
428 Output_data_plt_x86_64
*
431 gold_assert(this->plt_
!= NULL
);
435 // Get the dynamic reloc section, creating it if necessary.
437 rela_dyn_section(Layout
*);
439 // Get the section to use for TLSDESC relocations.
441 rela_tlsdesc_section(Layout
*) const;
443 // Add a potential copy relocation.
445 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
446 Sized_relobj
<64, false>* object
,
447 unsigned int shndx
, Output_section
* output_section
,
448 Symbol
* sym
, const elfcpp::Rela
<64, false>& reloc
)
450 this->copy_relocs_
.copy_reloc(symtab
, layout
,
451 symtab
->get_sized_symbol
<64>(sym
),
452 object
, shndx
, output_section
,
453 reloc
, this->rela_dyn_section(layout
));
456 // Information about this specific target which we pass to the
457 // general Target structure.
458 static const Target::Target_info x86_64_info
;
462 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
463 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
464 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
465 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
468 // This type is used as the argument to the target specific
469 // relocation routines. The only target specific reloc is
470 // R_X86_64_TLSDESC against a local symbol.
473 Tlsdesc_info(Sized_relobj
<64, false>* a_object
, unsigned int a_r_sym
)
474 : object(a_object
), r_sym(a_r_sym
)
477 // The object in which the local symbol is defined.
478 Sized_relobj
<64, false>* object
;
479 // The local symbol index in the object.
484 Output_data_got
<64, false>* got_
;
486 Output_data_plt_x86_64
* plt_
;
487 // The GOT PLT section.
488 Output_data_space
* got_plt_
;
489 // The _GLOBAL_OFFSET_TABLE_ symbol.
490 Symbol
* global_offset_table_
;
491 // The dynamic reloc section.
492 Reloc_section
* rela_dyn_
;
493 // Relocs saved to avoid a COPY reloc.
494 Copy_relocs
<elfcpp::SHT_RELA
, 64, false> copy_relocs_
;
495 // Space for variables copied with a COPY reloc.
496 Output_data_space
* dynbss_
;
497 // Offset of the GOT entry for the TLS module index.
498 unsigned int got_mod_index_offset_
;
499 // We handle R_X86_64_TLSDESC against a local symbol as a target
500 // specific relocation. Here we store the object and local symbol
501 // index for the relocation.
502 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
503 // True if the _TLS_MODULE_BASE_ symbol has been defined.
504 bool tls_base_symbol_defined_
;
507 const Target::Target_info
Target_x86_64::x86_64_info
=
510 false, // is_big_endian
511 elfcpp::EM_X86_64
, // machine_code
512 false, // has_make_symbol
513 false, // has_resolve
514 true, // has_code_fill
515 true, // is_default_stack_executable
517 "/lib/ld64.so.1", // program interpreter
518 0x400000, // default_text_segment_address
519 0x1000, // abi_pagesize (overridable by -z max-page-size)
520 0x1000, // common_pagesize (overridable by -z common-page-size)
521 elfcpp::SHN_UNDEF
, // small_common_shndx
522 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
523 0, // small_common_section_flags
524 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
525 NULL
, // attributes_section
526 NULL
// attributes_vendor
529 // This is called when a new output section is created. This is where
530 // we handle the SHF_X86_64_LARGE.
533 Target_x86_64::do_new_output_section(Output_section
*os
) const
535 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
536 os
->set_is_large_section();
539 // Get the GOT section, creating it if necessary.
541 Output_data_got
<64, false>*
542 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
544 if (this->got_
== NULL
)
546 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
548 this->got_
= new Output_data_got
<64, false>();
550 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
552 | elfcpp::SHF_WRITE
),
553 this->got_
, false, true, true, false);
555 this->got_plt_
= new Output_data_space(8, "** GOT PLT");
556 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
558 | elfcpp::SHF_WRITE
),
559 this->got_plt_
, false, false, false,
562 // The first three entries are reserved.
563 this->got_plt_
->set_current_data_size(3 * 8);
565 // Those bytes can go into the relro segment.
566 layout
->increase_relro(3 * 8);
568 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
569 this->global_offset_table_
=
570 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
571 Symbol_table::PREDEFINED
,
573 0, 0, elfcpp::STT_OBJECT
,
575 elfcpp::STV_HIDDEN
, 0,
582 // Get the dynamic reloc section, creating it if necessary.
584 Target_x86_64::Reloc_section
*
585 Target_x86_64::rela_dyn_section(Layout
* layout
)
587 if (this->rela_dyn_
== NULL
)
589 gold_assert(layout
!= NULL
);
590 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
591 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
592 elfcpp::SHF_ALLOC
, this->rela_dyn_
, true,
593 false, false, false);
595 return this->rela_dyn_
;
598 // A class to handle the PLT data.
600 class Output_data_plt_x86_64
: public Output_section_data
603 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
605 Output_data_plt_x86_64(Layout
*, Output_data_got
<64, false>*,
608 // Add an entry to the PLT.
610 add_entry(Symbol
* gsym
);
612 // Add the reserved TLSDESC_PLT entry to the PLT.
614 reserve_tlsdesc_entry(unsigned int got_offset
)
615 { this->tlsdesc_got_offset_
= got_offset
; }
617 // Return true if a TLSDESC_PLT entry has been reserved.
619 has_tlsdesc_entry() const
620 { return this->tlsdesc_got_offset_
!= -1U; }
622 // Return the GOT offset for the reserved TLSDESC_PLT entry.
624 get_tlsdesc_got_offset() const
625 { return this->tlsdesc_got_offset_
; }
627 // Return the offset of the reserved TLSDESC_PLT entry.
629 get_tlsdesc_plt_offset() const
630 { return (this->count_
+ 1) * plt_entry_size
; }
632 // Return the .rela.plt section data.
635 { return this->rel_
; }
637 // Return where the TLSDESC relocations should go.
639 rela_tlsdesc(Layout
*);
643 do_adjust_output_section(Output_section
* os
);
645 // Write to a map file.
647 do_print_to_mapfile(Mapfile
* mapfile
) const
648 { mapfile
->print_output_data(this, _("** PLT")); }
651 // The size of an entry in the PLT.
652 static const int plt_entry_size
= 16;
654 // The first entry in the PLT.
655 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
656 // procedure linkage table for both programs and shared objects."
657 static unsigned char first_plt_entry
[plt_entry_size
];
659 // Other entries in the PLT for an executable.
660 static unsigned char plt_entry
[plt_entry_size
];
662 // The reserved TLSDESC entry in the PLT for an executable.
663 static unsigned char tlsdesc_plt_entry
[plt_entry_size
];
665 // Set the final size.
667 set_final_data_size();
669 // Write out the PLT data.
671 do_write(Output_file
*);
673 // The reloc section.
675 // The TLSDESC relocs, if necessary. These must follow the regular
677 Reloc_section
* tlsdesc_rel_
;
679 Output_data_got
<64, false>* got_
;
680 // The .got.plt section.
681 Output_data_space
* got_plt_
;
682 // The number of PLT entries.
684 // Offset of the reserved TLSDESC_GOT entry when needed.
685 unsigned int tlsdesc_got_offset_
;
688 // Create the PLT section. The ordinary .got section is an argument,
689 // since we need to refer to the start. We also create our own .got
690 // section just for PLT entries.
692 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout
* layout
,
693 Output_data_got
<64, false>* got
,
694 Output_data_space
* got_plt
)
695 : Output_section_data(8), tlsdesc_rel_(NULL
), got_(got
), got_plt_(got_plt
),
696 count_(0), tlsdesc_got_offset_(-1U)
698 this->rel_
= new Reloc_section(false);
699 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
700 elfcpp::SHF_ALLOC
, this->rel_
, true,
701 false, false, false);
705 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
707 os
->set_entsize(plt_entry_size
);
710 // Add an entry to the PLT.
713 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
715 gold_assert(!gsym
->has_plt_offset());
717 // Note that when setting the PLT offset we skip the initial
718 // reserved PLT entry.
719 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
723 section_offset_type got_offset
= this->got_plt_
->current_data_size();
725 // Every PLT entry needs a GOT entry which points back to the PLT
726 // entry (this will be changed by the dynamic linker, normally
727 // lazily when the function is called).
728 this->got_plt_
->set_current_data_size(got_offset
+ 8);
730 // Every PLT entry needs a reloc.
731 gsym
->set_needs_dynsym_entry();
732 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
735 // Note that we don't need to save the symbol. The contents of the
736 // PLT are independent of which symbols are used. The symbols only
737 // appear in the relocations.
740 // Return where the TLSDESC relocations should go, creating it if
741 // necessary. These follow the JUMP_SLOT relocations.
743 Output_data_plt_x86_64::Reloc_section
*
744 Output_data_plt_x86_64::rela_tlsdesc(Layout
* layout
)
746 if (this->tlsdesc_rel_
== NULL
)
748 this->tlsdesc_rel_
= new Reloc_section(false);
749 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
750 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
751 true, false, false, false);
752 gold_assert(this->tlsdesc_rel_
->output_section() ==
753 this->rel_
->output_section());
755 return this->tlsdesc_rel_
;
758 // Set the final size.
760 Output_data_plt_x86_64::set_final_data_size()
762 unsigned int count
= this->count_
;
763 if (this->has_tlsdesc_entry())
765 this->set_data_size((count
+ 1) * plt_entry_size
);
768 // The first entry in the PLT for an executable.
770 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
772 // From AMD64 ABI Draft 0.98, page 76
773 0xff, 0x35, // pushq contents of memory address
774 0, 0, 0, 0, // replaced with address of .got + 8
775 0xff, 0x25, // jmp indirect
776 0, 0, 0, 0, // replaced with address of .got + 16
777 0x90, 0x90, 0x90, 0x90 // noop (x4)
780 // Subsequent entries in the PLT for an executable.
782 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
784 // From AMD64 ABI Draft 0.98, page 76
785 0xff, 0x25, // jmpq indirect
786 0, 0, 0, 0, // replaced with address of symbol in .got
787 0x68, // pushq immediate
788 0, 0, 0, 0, // replaced with offset into relocation table
789 0xe9, // jmpq relative
790 0, 0, 0, 0 // replaced with offset to start of .plt
793 // The reserved TLSDESC entry in the PLT for an executable.
795 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry
[plt_entry_size
] =
797 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
798 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
799 0xff, 0x35, // pushq x(%rip)
800 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
801 0xff, 0x25, // jmpq *y(%rip)
802 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
807 // Write out the PLT. This uses the hand-coded instructions above,
808 // and adjusts them as needed. This is specified by the AMD64 ABI.
811 Output_data_plt_x86_64::do_write(Output_file
* of
)
813 const off_t offset
= this->offset();
814 const section_size_type oview_size
=
815 convert_to_section_size_type(this->data_size());
816 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
818 const off_t got_file_offset
= this->got_plt_
->offset();
819 const section_size_type got_size
=
820 convert_to_section_size_type(this->got_plt_
->data_size());
821 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
824 unsigned char* pov
= oview
;
826 // The base address of the .plt section.
827 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
828 // The base address of the .got section.
829 elfcpp::Elf_types
<64>::Elf_Addr got_base
= this->got_
->address();
830 // The base address of the PLT portion of the .got section,
831 // which is where the GOT pointer will point, and where the
832 // three reserved GOT entries are located.
833 elfcpp::Elf_types
<64>::Elf_Addr got_address
= this->got_plt_
->address();
835 memcpy(pov
, first_plt_entry
, plt_entry_size
);
836 // We do a jmp relative to the PC at the end of this instruction.
837 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
839 - (plt_address
+ 6)));
840 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
842 - (plt_address
+ 12)));
843 pov
+= plt_entry_size
;
845 unsigned char* got_pov
= got_view
;
847 memset(got_pov
, 0, 24);
850 unsigned int plt_offset
= plt_entry_size
;
851 unsigned int got_offset
= 24;
852 const unsigned int count
= this->count_
;
853 for (unsigned int plt_index
= 0;
856 pov
+= plt_entry_size
,
858 plt_offset
+= plt_entry_size
,
861 // Set and adjust the PLT entry itself.
862 memcpy(pov
, plt_entry
, plt_entry_size
);
863 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
864 (got_address
+ got_offset
865 - (plt_address
+ plt_offset
868 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
869 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
870 - (plt_offset
+ plt_entry_size
));
872 // Set the entry in the GOT.
873 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
876 if (this->has_tlsdesc_entry())
878 // Set and adjust the reserved TLSDESC PLT entry.
879 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
880 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
881 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
883 - (plt_address
+ plt_offset
885 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
888 - (plt_address
+ plt_offset
890 pov
+= plt_entry_size
;
893 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
894 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
896 of
->write_output_view(offset
, oview_size
, oview
);
897 of
->write_output_view(got_file_offset
, got_size
, got_view
);
900 // Create the PLT section.
903 Target_x86_64::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
905 if (this->plt_
== NULL
)
907 // Create the GOT sections first.
908 this->got_section(symtab
, layout
);
910 this->plt_
= new Output_data_plt_x86_64(layout
, this->got_
,
912 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
914 | elfcpp::SHF_EXECINSTR
),
915 this->plt_
, false, false, false, false);
919 // Return the section for TLSDESC relocations.
921 Target_x86_64::Reloc_section
*
922 Target_x86_64::rela_tlsdesc_section(Layout
* layout
) const
924 return this->plt_section()->rela_tlsdesc(layout
);
927 // Create a PLT entry for a global symbol.
930 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
933 if (gsym
->has_plt_offset())
936 if (this->plt_
== NULL
)
937 this->make_plt_section(symtab
, layout
);
939 this->plt_
->add_entry(gsym
);
942 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
945 Target_x86_64::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
947 if (this->tls_base_symbol_defined_
)
950 Output_segment
* tls_segment
= layout
->tls_segment();
951 if (tls_segment
!= NULL
)
953 bool is_exec
= parameters
->options().output_is_executable();
954 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
955 Symbol_table::PREDEFINED
,
959 elfcpp::STV_HIDDEN
, 0,
961 ? Symbol::SEGMENT_END
962 : Symbol::SEGMENT_START
),
965 this->tls_base_symbol_defined_
= true;
968 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
971 Target_x86_64::reserve_tlsdesc_entries(Symbol_table
* symtab
,
974 if (this->plt_
== NULL
)
975 this->make_plt_section(symtab
, layout
);
977 if (!this->plt_
->has_tlsdesc_entry())
979 // Allocate the TLSDESC_GOT entry.
980 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
981 unsigned int got_offset
= got
->add_constant(0);
983 // Allocate the TLSDESC_PLT entry.
984 this->plt_
->reserve_tlsdesc_entry(got_offset
);
988 // Create a GOT entry for the TLS module index.
991 Target_x86_64::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
992 Sized_relobj
<64, false>* object
)
994 if (this->got_mod_index_offset_
== -1U)
996 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
997 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
998 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
999 unsigned int got_offset
= got
->add_constant(0);
1000 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
1002 got
->add_constant(0);
1003 this->got_mod_index_offset_
= got_offset
;
1005 return this->got_mod_index_offset_
;
1008 // Optimize the TLS relocation type based on what we know about the
1009 // symbol. IS_FINAL is true if the final address of this symbol is
1010 // known at link time.
1012 tls::Tls_optimization
1013 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
1015 // If we are generating a shared library, then we can't do anything
1017 if (parameters
->options().shared())
1018 return tls::TLSOPT_NONE
;
1022 case elfcpp::R_X86_64_TLSGD
:
1023 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1024 case elfcpp::R_X86_64_TLSDESC_CALL
:
1025 // These are General-Dynamic which permits fully general TLS
1026 // access. Since we know that we are generating an executable,
1027 // we can convert this to Initial-Exec. If we also know that
1028 // this is a local symbol, we can further switch to Local-Exec.
1030 return tls::TLSOPT_TO_LE
;
1031 return tls::TLSOPT_TO_IE
;
1033 case elfcpp::R_X86_64_TLSLD
:
1034 // This is Local-Dynamic, which refers to a local symbol in the
1035 // dynamic TLS block. Since we know that we generating an
1036 // executable, we can switch to Local-Exec.
1037 return tls::TLSOPT_TO_LE
;
1039 case elfcpp::R_X86_64_DTPOFF32
:
1040 case elfcpp::R_X86_64_DTPOFF64
:
1041 // Another Local-Dynamic reloc.
1042 return tls::TLSOPT_TO_LE
;
1044 case elfcpp::R_X86_64_GOTTPOFF
:
1045 // These are Initial-Exec relocs which get the thread offset
1046 // from the GOT. If we know that we are linking against the
1047 // local symbol, we can switch to Local-Exec, which links the
1048 // thread offset into the instruction.
1050 return tls::TLSOPT_TO_LE
;
1051 return tls::TLSOPT_NONE
;
1053 case elfcpp::R_X86_64_TPOFF32
:
1054 // When we already have Local-Exec, there is nothing further we
1056 return tls::TLSOPT_NONE
;
1063 // Report an unsupported relocation against a local symbol.
1066 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
1067 unsigned int r_type
)
1069 gold_error(_("%s: unsupported reloc %u against local symbol"),
1070 object
->name().c_str(), r_type
);
1073 // We are about to emit a dynamic relocation of type R_TYPE. If the
1074 // dynamic linker does not support it, issue an error. The GNU linker
1075 // only issues a non-PIC error for an allocated read-only section.
1076 // Here we know the section is allocated, but we don't know that it is
1077 // read-only. But we check for all the relocation types which the
1078 // glibc dynamic linker supports, so it seems appropriate to issue an
1079 // error even if the section is not read-only.
1082 Target_x86_64::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
)
1086 // These are the relocation types supported by glibc for x86_64.
1087 case elfcpp::R_X86_64_RELATIVE
:
1088 case elfcpp::R_X86_64_GLOB_DAT
:
1089 case elfcpp::R_X86_64_JUMP_SLOT
:
1090 case elfcpp::R_X86_64_DTPMOD64
:
1091 case elfcpp::R_X86_64_DTPOFF64
:
1092 case elfcpp::R_X86_64_TPOFF64
:
1093 case elfcpp::R_X86_64_64
:
1094 case elfcpp::R_X86_64_32
:
1095 case elfcpp::R_X86_64_PC32
:
1096 case elfcpp::R_X86_64_COPY
:
1100 // This prevents us from issuing more than one error per reloc
1101 // section. But we can still wind up issuing more than one
1102 // error per object file.
1103 if (this->issued_non_pic_error_
)
1105 gold_assert(parameters
->options().output_is_position_independent());
1106 object
->error(_("requires unsupported dynamic reloc; "
1107 "recompile with -fPIC"));
1108 this->issued_non_pic_error_
= true;
1111 case elfcpp::R_X86_64_NONE
:
1116 // Scan a relocation for a local symbol.
1119 Target_x86_64::Scan::local(Symbol_table
* symtab
,
1121 Target_x86_64
* target
,
1122 Sized_relobj
<64, false>* object
,
1123 unsigned int data_shndx
,
1124 Output_section
* output_section
,
1125 const elfcpp::Rela
<64, false>& reloc
,
1126 unsigned int r_type
,
1127 const elfcpp::Sym
<64, false>& lsym
)
1131 case elfcpp::R_X86_64_NONE
:
1132 case elfcpp::R_386_GNU_VTINHERIT
:
1133 case elfcpp::R_386_GNU_VTENTRY
:
1136 case elfcpp::R_X86_64_64
:
1137 // If building a shared library (or a position-independent
1138 // executable), we need to create a dynamic relocation for this
1139 // location. The relocation applied at link time will apply the
1140 // link-time value, so we flag the location with an
1141 // R_X86_64_RELATIVE relocation so the dynamic loader can
1142 // relocate it easily.
1143 if (parameters
->options().output_is_position_independent())
1145 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1146 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1147 rela_dyn
->add_local_relative(object
, r_sym
,
1148 elfcpp::R_X86_64_RELATIVE
,
1149 output_section
, data_shndx
,
1150 reloc
.get_r_offset(),
1151 reloc
.get_r_addend());
1155 case elfcpp::R_X86_64_32
:
1156 case elfcpp::R_X86_64_32S
:
1157 case elfcpp::R_X86_64_16
:
1158 case elfcpp::R_X86_64_8
:
1159 // If building a shared library (or a position-independent
1160 // executable), we need to create a dynamic relocation for this
1161 // location. We can't use an R_X86_64_RELATIVE relocation
1162 // because that is always a 64-bit relocation.
1163 if (parameters
->options().output_is_position_independent())
1165 this->check_non_pic(object
, r_type
);
1167 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1168 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1169 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1170 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1171 data_shndx
, reloc
.get_r_offset(),
1172 reloc
.get_r_addend());
1175 gold_assert(lsym
.get_st_value() == 0);
1176 unsigned int shndx
= lsym
.get_st_shndx();
1178 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1181 object
->error(_("section symbol %u has bad shndx %u"),
1184 rela_dyn
->add_local_section(object
, shndx
,
1185 r_type
, output_section
,
1186 data_shndx
, reloc
.get_r_offset(),
1187 reloc
.get_r_addend());
1192 case elfcpp::R_X86_64_PC64
:
1193 case elfcpp::R_X86_64_PC32
:
1194 case elfcpp::R_X86_64_PC16
:
1195 case elfcpp::R_X86_64_PC8
:
1198 case elfcpp::R_X86_64_PLT32
:
1199 // Since we know this is a local symbol, we can handle this as a
1203 case elfcpp::R_X86_64_GOTPC32
:
1204 case elfcpp::R_X86_64_GOTOFF64
:
1205 case elfcpp::R_X86_64_GOTPC64
:
1206 case elfcpp::R_X86_64_PLTOFF64
:
1207 // We need a GOT section.
1208 target
->got_section(symtab
, layout
);
1209 // For PLTOFF64, we'd normally want a PLT section, but since we
1210 // know this is a local symbol, no PLT is needed.
1213 case elfcpp::R_X86_64_GOT64
:
1214 case elfcpp::R_X86_64_GOT32
:
1215 case elfcpp::R_X86_64_GOTPCREL64
:
1216 case elfcpp::R_X86_64_GOTPCREL
:
1217 case elfcpp::R_X86_64_GOTPLT64
:
1219 // The symbol requires a GOT entry.
1220 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1221 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1222 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
1224 // If we are generating a shared object, we need to add a
1225 // dynamic relocation for this symbol's GOT entry.
1226 if (parameters
->options().output_is_position_independent())
1228 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1229 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1230 if (r_type
!= elfcpp::R_X86_64_GOT32
)
1231 rela_dyn
->add_local_relative(
1232 object
, r_sym
, elfcpp::R_X86_64_RELATIVE
, got
,
1233 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
1236 this->check_non_pic(object
, r_type
);
1238 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1239 rela_dyn
->add_local(
1240 object
, r_sym
, r_type
, got
,
1241 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
1245 // For GOTPLT64, we'd normally want a PLT section, but since
1246 // we know this is a local symbol, no PLT is needed.
1250 case elfcpp::R_X86_64_COPY
:
1251 case elfcpp::R_X86_64_GLOB_DAT
:
1252 case elfcpp::R_X86_64_JUMP_SLOT
:
1253 case elfcpp::R_X86_64_RELATIVE
:
1254 // These are outstanding tls relocs, which are unexpected when linking
1255 case elfcpp::R_X86_64_TPOFF64
:
1256 case elfcpp::R_X86_64_DTPMOD64
:
1257 case elfcpp::R_X86_64_TLSDESC
:
1258 gold_error(_("%s: unexpected reloc %u in object file"),
1259 object
->name().c_str(), r_type
);
1262 // These are initial tls relocs, which are expected when linking
1263 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1264 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1265 case elfcpp::R_X86_64_TLSDESC_CALL
:
1266 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1267 case elfcpp::R_X86_64_DTPOFF32
:
1268 case elfcpp::R_X86_64_DTPOFF64
:
1269 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1270 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1272 bool output_is_shared
= parameters
->options().shared();
1273 const tls::Tls_optimization optimized_type
1274 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
1277 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1278 if (optimized_type
== tls::TLSOPT_NONE
)
1280 // Create a pair of GOT entries for the module index and
1281 // dtv-relative offset.
1282 Output_data_got
<64, false>* got
1283 = target
->got_section(symtab
, layout
);
1284 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1285 unsigned int shndx
= lsym
.get_st_shndx();
1287 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1289 object
->error(_("local symbol %u has bad shndx %u"),
1292 got
->add_local_pair_with_rela(object
, r_sym
,
1295 target
->rela_dyn_section(layout
),
1296 elfcpp::R_X86_64_DTPMOD64
, 0);
1298 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1299 unsupported_reloc_local(object
, r_type
);
1302 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1303 target
->define_tls_base_symbol(symtab
, layout
);
1304 if (optimized_type
== tls::TLSOPT_NONE
)
1306 // Create reserved PLT and GOT entries for the resolver.
1307 target
->reserve_tlsdesc_entries(symtab
, layout
);
1309 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1310 Output_data_got
<64, false>* got
1311 = target
->got_section(symtab
, layout
);
1312 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1313 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1315 unsigned int got_offset
= got
->add_constant(0);
1316 got
->add_constant(0);
1317 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1319 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
1320 // We store the arguments we need in a vector, and
1321 // use the index into the vector as the parameter
1322 // to pass to the target specific routines.
1323 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
1324 void* arg
= reinterpret_cast<void*>(intarg
);
1325 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
1326 got
, got_offset
, 0);
1329 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1330 unsupported_reloc_local(object
, r_type
);
1333 case elfcpp::R_X86_64_TLSDESC_CALL
:
1336 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1337 if (optimized_type
== tls::TLSOPT_NONE
)
1339 // Create a GOT entry for the module index.
1340 target
->got_mod_index_entry(symtab
, layout
, object
);
1342 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1343 unsupported_reloc_local(object
, r_type
);
1346 case elfcpp::R_X86_64_DTPOFF32
:
1347 case elfcpp::R_X86_64_DTPOFF64
:
1350 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1351 layout
->set_has_static_tls();
1352 if (optimized_type
== tls::TLSOPT_NONE
)
1354 // Create a GOT entry for the tp-relative offset.
1355 Output_data_got
<64, false>* got
1356 = target
->got_section(symtab
, layout
);
1357 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1358 got
->add_local_with_rela(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
1359 target
->rela_dyn_section(layout
),
1360 elfcpp::R_X86_64_TPOFF64
);
1362 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1363 unsupported_reloc_local(object
, r_type
);
1366 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1367 layout
->set_has_static_tls();
1368 if (output_is_shared
)
1369 unsupported_reloc_local(object
, r_type
);
1378 case elfcpp::R_X86_64_SIZE32
:
1379 case elfcpp::R_X86_64_SIZE64
:
1381 gold_error(_("%s: unsupported reloc %u against local symbol"),
1382 object
->name().c_str(), r_type
);
1388 // Report an unsupported relocation against a global symbol.
1391 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
1392 unsigned int r_type
,
1395 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1396 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1399 // Returns true if this relocation type could be that of a function pointer.
1401 Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1405 case elfcpp::R_X86_64_64
:
1406 case elfcpp::R_X86_64_32
:
1407 case elfcpp::R_X86_64_32S
:
1408 case elfcpp::R_X86_64_16
:
1409 case elfcpp::R_X86_64_8
:
1410 case elfcpp::R_X86_64_GOT64
:
1411 case elfcpp::R_X86_64_GOT32
:
1412 case elfcpp::R_X86_64_GOTPCREL64
:
1413 case elfcpp::R_X86_64_GOTPCREL
:
1414 case elfcpp::R_X86_64_GOTPLT64
:
1422 // For safe ICF, scan a relocation for a local symbol to check if it
1423 // corresponds to a function pointer being taken. In that case mark
1424 // the function whose pointer was taken as not foldable.
1427 Target_x86_64::Scan::local_reloc_may_be_function_pointer(
1431 Sized_relobj
<64, false>* ,
1434 const elfcpp::Rela
<64, false>& ,
1435 unsigned int r_type
,
1436 const elfcpp::Sym
<64, false>&)
1438 // When building a shared library, do not fold any local symbols as it is
1439 // not possible to distinguish pointer taken versus a call by looking at
1440 // the relocation types.
1441 return (parameters
->options().shared()
1442 || possible_function_pointer_reloc(r_type
));
1445 // For safe ICF, scan a relocation for a global symbol to check if it
1446 // corresponds to a function pointer being taken. In that case mark
1447 // the function whose pointer was taken as not foldable.
1450 Target_x86_64::Scan::global_reloc_may_be_function_pointer(
1454 Sized_relobj
<64, false>* ,
1457 const elfcpp::Rela
<64, false>& ,
1458 unsigned int r_type
,
1461 // When building a shared library, do not fold symbols whose visibility
1462 // is hidden, internal or protected.
1463 return ((parameters
->options().shared()
1464 && (gsym
->visibility() == elfcpp::STV_INTERNAL
1465 || gsym
->visibility() == elfcpp::STV_PROTECTED
1466 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
1467 || possible_function_pointer_reloc(r_type
));
1470 // Scan a relocation for a global symbol.
1473 Target_x86_64::Scan::global(Symbol_table
* symtab
,
1475 Target_x86_64
* target
,
1476 Sized_relobj
<64, false>* object
,
1477 unsigned int data_shndx
,
1478 Output_section
* output_section
,
1479 const elfcpp::Rela
<64, false>& reloc
,
1480 unsigned int r_type
,
1485 case elfcpp::R_X86_64_NONE
:
1486 case elfcpp::R_386_GNU_VTINHERIT
:
1487 case elfcpp::R_386_GNU_VTENTRY
:
1490 case elfcpp::R_X86_64_64
:
1491 case elfcpp::R_X86_64_32
:
1492 case elfcpp::R_X86_64_32S
:
1493 case elfcpp::R_X86_64_16
:
1494 case elfcpp::R_X86_64_8
:
1496 // Make a PLT entry if necessary.
1497 if (gsym
->needs_plt_entry())
1499 target
->make_plt_entry(symtab
, layout
, gsym
);
1500 // Since this is not a PC-relative relocation, we may be
1501 // taking the address of a function. In that case we need to
1502 // set the entry in the dynamic symbol table to the address of
1504 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1505 gsym
->set_needs_dynsym_value();
1507 // Make a dynamic relocation if necessary.
1508 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1510 if (gsym
->may_need_copy_reloc())
1512 target
->copy_reloc(symtab
, layout
, object
,
1513 data_shndx
, output_section
, gsym
, reloc
);
1515 else if (r_type
== elfcpp::R_X86_64_64
1516 && gsym
->can_use_relative_reloc(false))
1518 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1519 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1520 output_section
, object
,
1521 data_shndx
, reloc
.get_r_offset(),
1522 reloc
.get_r_addend());
1526 this->check_non_pic(object
, r_type
);
1527 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1528 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1529 data_shndx
, reloc
.get_r_offset(),
1530 reloc
.get_r_addend());
1536 case elfcpp::R_X86_64_PC64
:
1537 case elfcpp::R_X86_64_PC32
:
1538 case elfcpp::R_X86_64_PC16
:
1539 case elfcpp::R_X86_64_PC8
:
1541 // Make a PLT entry if necessary.
1542 if (gsym
->needs_plt_entry())
1543 target
->make_plt_entry(symtab
, layout
, gsym
);
1544 // Make a dynamic relocation if necessary.
1545 int flags
= Symbol::NON_PIC_REF
;
1546 if (gsym
->is_func())
1547 flags
|= Symbol::FUNCTION_CALL
;
1548 if (gsym
->needs_dynamic_reloc(flags
))
1550 if (gsym
->may_need_copy_reloc())
1552 target
->copy_reloc(symtab
, layout
, object
,
1553 data_shndx
, output_section
, gsym
, reloc
);
1557 this->check_non_pic(object
, r_type
);
1558 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1559 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1560 data_shndx
, reloc
.get_r_offset(),
1561 reloc
.get_r_addend());
1567 case elfcpp::R_X86_64_GOT64
:
1568 case elfcpp::R_X86_64_GOT32
:
1569 case elfcpp::R_X86_64_GOTPCREL64
:
1570 case elfcpp::R_X86_64_GOTPCREL
:
1571 case elfcpp::R_X86_64_GOTPLT64
:
1573 // The symbol requires a GOT entry.
1574 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1575 if (gsym
->final_value_is_known())
1576 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1579 // If this symbol is not fully resolved, we need to add a
1580 // dynamic relocation for it.
1581 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1582 if (gsym
->is_from_dynobj()
1583 || gsym
->is_undefined()
1584 || gsym
->is_preemptible())
1585 got
->add_global_with_rela(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
1586 elfcpp::R_X86_64_GLOB_DAT
);
1589 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
1590 rela_dyn
->add_global_relative(
1591 gsym
, elfcpp::R_X86_64_RELATIVE
, got
,
1592 gsym
->got_offset(GOT_TYPE_STANDARD
), 0);
1595 // For GOTPLT64, we also need a PLT entry (but only if the
1596 // symbol is not fully resolved).
1597 if (r_type
== elfcpp::R_X86_64_GOTPLT64
1598 && !gsym
->final_value_is_known())
1599 target
->make_plt_entry(symtab
, layout
, gsym
);
1603 case elfcpp::R_X86_64_PLT32
:
1604 // If the symbol is fully resolved, this is just a PC32 reloc.
1605 // Otherwise we need a PLT entry.
1606 if (gsym
->final_value_is_known())
1608 // If building a shared library, we can also skip the PLT entry
1609 // if the symbol is defined in the output file and is protected
1611 if (gsym
->is_defined()
1612 && !gsym
->is_from_dynobj()
1613 && !gsym
->is_preemptible())
1615 target
->make_plt_entry(symtab
, layout
, gsym
);
1618 case elfcpp::R_X86_64_GOTPC32
:
1619 case elfcpp::R_X86_64_GOTOFF64
:
1620 case elfcpp::R_X86_64_GOTPC64
:
1621 case elfcpp::R_X86_64_PLTOFF64
:
1622 // We need a GOT section.
1623 target
->got_section(symtab
, layout
);
1624 // For PLTOFF64, we also need a PLT entry (but only if the
1625 // symbol is not fully resolved).
1626 if (r_type
== elfcpp::R_X86_64_PLTOFF64
1627 && !gsym
->final_value_is_known())
1628 target
->make_plt_entry(symtab
, layout
, gsym
);
1631 case elfcpp::R_X86_64_COPY
:
1632 case elfcpp::R_X86_64_GLOB_DAT
:
1633 case elfcpp::R_X86_64_JUMP_SLOT
:
1634 case elfcpp::R_X86_64_RELATIVE
:
1635 // These are outstanding tls relocs, which are unexpected when linking
1636 case elfcpp::R_X86_64_TPOFF64
:
1637 case elfcpp::R_X86_64_DTPMOD64
:
1638 case elfcpp::R_X86_64_TLSDESC
:
1639 gold_error(_("%s: unexpected reloc %u in object file"),
1640 object
->name().c_str(), r_type
);
1643 // These are initial tls relocs, which are expected for global()
1644 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1645 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1646 case elfcpp::R_X86_64_TLSDESC_CALL
:
1647 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1648 case elfcpp::R_X86_64_DTPOFF32
:
1649 case elfcpp::R_X86_64_DTPOFF64
:
1650 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1651 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1653 const bool is_final
= gsym
->final_value_is_known();
1654 const tls::Tls_optimization optimized_type
1655 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1658 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1659 if (optimized_type
== tls::TLSOPT_NONE
)
1661 // Create a pair of GOT entries for the module index and
1662 // dtv-relative offset.
1663 Output_data_got
<64, false>* got
1664 = target
->got_section(symtab
, layout
);
1665 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_PAIR
,
1666 target
->rela_dyn_section(layout
),
1667 elfcpp::R_X86_64_DTPMOD64
,
1668 elfcpp::R_X86_64_DTPOFF64
);
1670 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1672 // Create a GOT entry for the tp-relative offset.
1673 Output_data_got
<64, false>* got
1674 = target
->got_section(symtab
, layout
);
1675 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1676 target
->rela_dyn_section(layout
),
1677 elfcpp::R_X86_64_TPOFF64
);
1679 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1680 unsupported_reloc_global(object
, r_type
, gsym
);
1683 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1684 target
->define_tls_base_symbol(symtab
, layout
);
1685 if (optimized_type
== tls::TLSOPT_NONE
)
1687 // Create reserved PLT and GOT entries for the resolver.
1688 target
->reserve_tlsdesc_entries(symtab
, layout
);
1690 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1691 Output_data_got
<64, false>* got
1692 = target
->got_section(symtab
, layout
);
1693 Reloc_section
*rt
= target
->rela_tlsdesc_section(layout
);
1694 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_DESC
, rt
,
1695 elfcpp::R_X86_64_TLSDESC
, 0);
1697 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1699 // Create a GOT entry for the tp-relative offset.
1700 Output_data_got
<64, false>* got
1701 = target
->got_section(symtab
, layout
);
1702 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1703 target
->rela_dyn_section(layout
),
1704 elfcpp::R_X86_64_TPOFF64
);
1706 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1707 unsupported_reloc_global(object
, r_type
, gsym
);
1710 case elfcpp::R_X86_64_TLSDESC_CALL
:
1713 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1714 if (optimized_type
== tls::TLSOPT_NONE
)
1716 // Create a GOT entry for the module index.
1717 target
->got_mod_index_entry(symtab
, layout
, object
);
1719 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1720 unsupported_reloc_global(object
, r_type
, gsym
);
1723 case elfcpp::R_X86_64_DTPOFF32
:
1724 case elfcpp::R_X86_64_DTPOFF64
:
1727 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1728 layout
->set_has_static_tls();
1729 if (optimized_type
== tls::TLSOPT_NONE
)
1731 // Create a GOT entry for the tp-relative offset.
1732 Output_data_got
<64, false>* got
1733 = target
->got_section(symtab
, layout
);
1734 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1735 target
->rela_dyn_section(layout
),
1736 elfcpp::R_X86_64_TPOFF64
);
1738 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1739 unsupported_reloc_global(object
, r_type
, gsym
);
1742 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1743 layout
->set_has_static_tls();
1744 if (parameters
->options().shared())
1745 unsupported_reloc_local(object
, r_type
);
1754 case elfcpp::R_X86_64_SIZE32
:
1755 case elfcpp::R_X86_64_SIZE64
:
1757 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1758 object
->name().c_str(), r_type
,
1759 gsym
->demangled_name().c_str());
1765 Target_x86_64::gc_process_relocs(Symbol_table
* symtab
,
1767 Sized_relobj
<64, false>* object
,
1768 unsigned int data_shndx
,
1769 unsigned int sh_type
,
1770 const unsigned char* prelocs
,
1772 Output_section
* output_section
,
1773 bool needs_special_offset_handling
,
1774 size_t local_symbol_count
,
1775 const unsigned char* plocal_symbols
)
1778 if (sh_type
== elfcpp::SHT_REL
)
1783 gold::gc_process_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1784 Target_x86_64::Scan
>(
1793 needs_special_offset_handling
,
1798 // Scan relocations for a section.
1801 Target_x86_64::scan_relocs(Symbol_table
* symtab
,
1803 Sized_relobj
<64, false>* object
,
1804 unsigned int data_shndx
,
1805 unsigned int sh_type
,
1806 const unsigned char* prelocs
,
1808 Output_section
* output_section
,
1809 bool needs_special_offset_handling
,
1810 size_t local_symbol_count
,
1811 const unsigned char* plocal_symbols
)
1813 if (sh_type
== elfcpp::SHT_REL
)
1815 gold_error(_("%s: unsupported REL reloc section"),
1816 object
->name().c_str());
1820 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
1821 Target_x86_64::Scan
>(
1830 needs_special_offset_handling
,
1835 // Finalize the sections.
1838 Target_x86_64::do_finalize_sections(
1840 const Input_objects
*,
1841 Symbol_table
* symtab
)
1843 const Reloc_section
* rel_plt
= (this->plt_
== NULL
1845 : this->plt_
->rela_plt());
1846 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
1847 this->rela_dyn_
, true, false);
1849 // Fill in some more dynamic tags.
1850 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
1853 if (this->plt_
!= NULL
1854 && this->plt_
->output_section() != NULL
1855 && this->plt_
->has_tlsdesc_entry())
1857 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
1858 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
1859 this->got_
->finalize_data_size();
1860 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
1861 this->plt_
, plt_offset
);
1862 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
1863 this->got_
, got_offset
);
1867 // Emit any relocs we saved in an attempt to avoid generating COPY
1869 if (this->copy_relocs_
.any_saved_relocs())
1870 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
1872 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1873 // the .got.plt section.
1874 Symbol
* sym
= this->global_offset_table_
;
1877 uint64_t data_size
= this->got_plt_
->current_data_size();
1878 symtab
->get_sized_symbol
<64>(sym
)->set_symsize(data_size
);
1882 // Perform a relocation.
1885 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
1886 Target_x86_64
* target
,
1889 const elfcpp::Rela
<64, false>& rela
,
1890 unsigned int r_type
,
1891 const Sized_symbol
<64>* gsym
,
1892 const Symbol_value
<64>* psymval
,
1893 unsigned char* view
,
1894 elfcpp::Elf_types
<64>::Elf_Addr address
,
1895 section_size_type view_size
)
1897 if (this->skip_call_tls_get_addr_
)
1899 if ((r_type
!= elfcpp::R_X86_64_PLT32
1900 && r_type
!= elfcpp::R_X86_64_PC32
)
1902 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
1904 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
1905 _("missing expected TLS relocation"));
1909 this->skip_call_tls_get_addr_
= false;
1914 // Pick the value to use for symbols defined in shared objects.
1915 Symbol_value
<64> symval
;
1917 && gsym
->use_plt_offset(r_type
== elfcpp::R_X86_64_PC64
1918 || r_type
== elfcpp::R_X86_64_PC32
1919 || r_type
== elfcpp::R_X86_64_PC16
1920 || r_type
== elfcpp::R_X86_64_PC8
))
1922 symval
.set_output_value(target
->plt_section()->address()
1923 + gsym
->plt_offset());
1927 const Sized_relobj
<64, false>* object
= relinfo
->object
;
1928 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
1930 // Get the GOT offset if needed.
1931 // The GOT pointer points to the end of the GOT section.
1932 // We need to subtract the size of the GOT section to get
1933 // the actual offset to use in the relocation.
1934 bool have_got_offset
= false;
1935 unsigned int got_offset
= 0;
1938 case elfcpp::R_X86_64_GOT32
:
1939 case elfcpp::R_X86_64_GOT64
:
1940 case elfcpp::R_X86_64_GOTPLT64
:
1941 case elfcpp::R_X86_64_GOTPCREL
:
1942 case elfcpp::R_X86_64_GOTPCREL64
:
1945 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
1946 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
1950 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
1951 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
1952 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
1953 - target
->got_size());
1955 have_got_offset
= true;
1964 case elfcpp::R_X86_64_NONE
:
1965 case elfcpp::R_386_GNU_VTINHERIT
:
1966 case elfcpp::R_386_GNU_VTENTRY
:
1969 case elfcpp::R_X86_64_64
:
1970 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
1973 case elfcpp::R_X86_64_PC64
:
1974 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
1978 case elfcpp::R_X86_64_32
:
1979 // FIXME: we need to verify that value + addend fits into 32 bits:
1980 // uint64_t x = value + addend;
1981 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1982 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1983 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1986 case elfcpp::R_X86_64_32S
:
1987 // FIXME: we need to verify that value + addend fits into 32 bits:
1988 // int64_t x = value + addend; // note this quantity is signed!
1989 // x == static_cast<int64_t>(static_cast<int32_t>(x))
1990 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
1993 case elfcpp::R_X86_64_PC32
:
1994 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
1998 case elfcpp::R_X86_64_16
:
1999 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
2002 case elfcpp::R_X86_64_PC16
:
2003 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
2007 case elfcpp::R_X86_64_8
:
2008 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
2011 case elfcpp::R_X86_64_PC8
:
2012 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
2016 case elfcpp::R_X86_64_PLT32
:
2017 gold_assert(gsym
== NULL
2018 || gsym
->has_plt_offset()
2019 || gsym
->final_value_is_known()
2020 || (gsym
->is_defined()
2021 && !gsym
->is_from_dynobj()
2022 && !gsym
->is_preemptible()));
2023 // Note: while this code looks the same as for R_X86_64_PC32, it
2024 // behaves differently because psymval was set to point to
2025 // the PLT entry, rather than the symbol, in Scan::global().
2026 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2030 case elfcpp::R_X86_64_PLTOFF64
:
2033 gold_assert(gsym
->has_plt_offset()
2034 || gsym
->final_value_is_known());
2035 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
2036 got_address
= target
->got_section(NULL
, NULL
)->address();
2037 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
2038 addend
- got_address
);
2041 case elfcpp::R_X86_64_GOT32
:
2042 gold_assert(have_got_offset
);
2043 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
2046 case elfcpp::R_X86_64_GOTPC32
:
2049 elfcpp::Elf_types
<64>::Elf_Addr value
;
2050 value
= target
->got_plt_section()->address();
2051 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2055 case elfcpp::R_X86_64_GOT64
:
2056 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
2057 // Since we always add a PLT entry, this is equivalent.
2058 case elfcpp::R_X86_64_GOTPLT64
:
2059 gold_assert(have_got_offset
);
2060 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
2063 case elfcpp::R_X86_64_GOTPC64
:
2066 elfcpp::Elf_types
<64>::Elf_Addr value
;
2067 value
= target
->got_plt_section()->address();
2068 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
2072 case elfcpp::R_X86_64_GOTOFF64
:
2074 elfcpp::Elf_types
<64>::Elf_Addr value
;
2075 value
= (psymval
->value(object
, 0)
2076 - target
->got_plt_section()->address());
2077 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2081 case elfcpp::R_X86_64_GOTPCREL
:
2083 gold_assert(have_got_offset
);
2084 elfcpp::Elf_types
<64>::Elf_Addr value
;
2085 value
= target
->got_plt_section()->address() + got_offset
;
2086 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2090 case elfcpp::R_X86_64_GOTPCREL64
:
2092 gold_assert(have_got_offset
);
2093 elfcpp::Elf_types
<64>::Elf_Addr value
;
2094 value
= target
->got_plt_section()->address() + got_offset
;
2095 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
2099 case elfcpp::R_X86_64_COPY
:
2100 case elfcpp::R_X86_64_GLOB_DAT
:
2101 case elfcpp::R_X86_64_JUMP_SLOT
:
2102 case elfcpp::R_X86_64_RELATIVE
:
2103 // These are outstanding tls relocs, which are unexpected when linking
2104 case elfcpp::R_X86_64_TPOFF64
:
2105 case elfcpp::R_X86_64_DTPMOD64
:
2106 case elfcpp::R_X86_64_TLSDESC
:
2107 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2108 _("unexpected reloc %u in object file"),
2112 // These are initial tls relocs, which are expected when linking
2113 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2114 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2115 case elfcpp::R_X86_64_TLSDESC_CALL
:
2116 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2117 case elfcpp::R_X86_64_DTPOFF32
:
2118 case elfcpp::R_X86_64_DTPOFF64
:
2119 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2120 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2121 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
2122 view
, address
, view_size
);
2125 case elfcpp::R_X86_64_SIZE32
:
2126 case elfcpp::R_X86_64_SIZE64
:
2128 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2129 _("unsupported reloc %u"),
2137 // Perform a TLS relocation.
2140 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
2141 Target_x86_64
* target
,
2143 const elfcpp::Rela
<64, false>& rela
,
2144 unsigned int r_type
,
2145 const Sized_symbol
<64>* gsym
,
2146 const Symbol_value
<64>* psymval
,
2147 unsigned char* view
,
2148 elfcpp::Elf_types
<64>::Elf_Addr address
,
2149 section_size_type view_size
)
2151 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2153 const Sized_relobj
<64, false>* object
= relinfo
->object
;
2154 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2156 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
2158 const bool is_final
= (gsym
== NULL
2159 ? !parameters
->options().shared()
2160 : gsym
->final_value_is_known());
2161 const tls::Tls_optimization optimized_type
2162 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
2165 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2166 this->saw_tls_block_reloc_
= true;
2167 if (optimized_type
== tls::TLSOPT_TO_LE
)
2169 gold_assert(tls_segment
!= NULL
);
2170 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2171 rela
, r_type
, value
, view
,
2177 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2178 ? GOT_TYPE_TLS_OFFSET
2179 : GOT_TYPE_TLS_PAIR
);
2180 unsigned int got_offset
;
2183 gold_assert(gsym
->has_got_offset(got_type
));
2184 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2188 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2189 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2190 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2191 - target
->got_size());
2193 if (optimized_type
== tls::TLSOPT_TO_IE
)
2195 gold_assert(tls_segment
!= NULL
);
2196 value
= target
->got_plt_section()->address() + got_offset
;
2197 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2198 value
, view
, address
, view_size
);
2201 else if (optimized_type
== tls::TLSOPT_NONE
)
2203 // Relocate the field with the offset of the pair of GOT
2205 value
= target
->got_plt_section()->address() + got_offset
;
2206 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2211 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2212 _("unsupported reloc %u"), r_type
);
2215 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2216 case elfcpp::R_X86_64_TLSDESC_CALL
:
2217 this->saw_tls_block_reloc_
= true;
2218 if (optimized_type
== tls::TLSOPT_TO_LE
)
2220 gold_assert(tls_segment
!= NULL
);
2221 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2222 rela
, r_type
, value
, view
,
2228 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2229 ? GOT_TYPE_TLS_OFFSET
2230 : GOT_TYPE_TLS_DESC
);
2231 unsigned int got_offset
;
2234 gold_assert(gsym
->has_got_offset(got_type
));
2235 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2239 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2240 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2241 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2242 - target
->got_size());
2244 if (optimized_type
== tls::TLSOPT_TO_IE
)
2246 gold_assert(tls_segment
!= NULL
);
2247 value
= target
->got_plt_section()->address() + got_offset
;
2248 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
,
2249 rela
, r_type
, value
, view
, address
,
2253 else if (optimized_type
== tls::TLSOPT_NONE
)
2255 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2257 // Relocate the field with the offset of the pair of GOT
2259 value
= target
->got_plt_section()->address() + got_offset
;
2260 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2266 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2267 _("unsupported reloc %u"), r_type
);
2270 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2271 this->saw_tls_block_reloc_
= true;
2272 if (optimized_type
== tls::TLSOPT_TO_LE
)
2274 gold_assert(tls_segment
!= NULL
);
2275 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2276 value
, view
, view_size
);
2279 else if (optimized_type
== tls::TLSOPT_NONE
)
2281 // Relocate the field with the offset of the GOT entry for
2282 // the module index.
2283 unsigned int got_offset
;
2284 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2285 - target
->got_size());
2286 value
= target
->got_plt_section()->address() + got_offset
;
2287 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2291 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2292 _("unsupported reloc %u"), r_type
);
2295 case elfcpp::R_X86_64_DTPOFF32
:
2296 if (optimized_type
== tls::TLSOPT_TO_LE
)
2298 // This relocation type is used in debugging information.
2299 // In that case we need to not optimize the value. If we
2300 // haven't seen a TLSLD reloc, then we assume we should not
2301 // optimize this reloc.
2302 if (this->saw_tls_block_reloc_
)
2304 gold_assert(tls_segment
!= NULL
);
2305 value
-= tls_segment
->memsz();
2308 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2311 case elfcpp::R_X86_64_DTPOFF64
:
2312 if (optimized_type
== tls::TLSOPT_TO_LE
)
2314 // See R_X86_64_DTPOFF32, just above, for why we test this.
2315 if (this->saw_tls_block_reloc_
)
2317 gold_assert(tls_segment
!= NULL
);
2318 value
-= tls_segment
->memsz();
2321 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2324 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2325 if (optimized_type
== tls::TLSOPT_TO_LE
)
2327 gold_assert(tls_segment
!= NULL
);
2328 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2329 rela
, r_type
, value
, view
,
2333 else if (optimized_type
== tls::TLSOPT_NONE
)
2335 // Relocate the field with the offset of the GOT entry for
2336 // the tp-relative offset of the symbol.
2337 unsigned int got_offset
;
2340 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
2341 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
2342 - target
->got_size());
2346 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2347 gold_assert(object
->local_has_got_offset(r_sym
,
2348 GOT_TYPE_TLS_OFFSET
));
2349 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
2350 - target
->got_size());
2352 value
= target
->got_plt_section()->address() + got_offset
;
2353 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2356 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2357 _("unsupported reloc type %u"),
2361 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2362 value
-= tls_segment
->memsz();
2363 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2368 // Do a relocation in which we convert a TLS General-Dynamic to an
2372 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info
<64, false>* relinfo
,
2375 const elfcpp::Rela
<64, false>& rela
,
2377 elfcpp::Elf_types
<64>::Elf_Addr value
,
2378 unsigned char* view
,
2379 elfcpp::Elf_types
<64>::Elf_Addr address
,
2380 section_size_type view_size
)
2382 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2383 // .word 0x6666; rex64; call __tls_get_addr
2384 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2386 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2387 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2389 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2390 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2391 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2392 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2394 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2396 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2397 Relocate_functions
<64, false>::pcrela32(view
+ 8, value
, addend
- 8, address
);
2399 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2401 this->skip_call_tls_get_addr_
= true;
2404 // Do a relocation in which we convert a TLS General-Dynamic to a
2408 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
2410 Output_segment
* tls_segment
,
2411 const elfcpp::Rela
<64, false>& rela
,
2413 elfcpp::Elf_types
<64>::Elf_Addr value
,
2414 unsigned char* view
,
2415 section_size_type view_size
)
2417 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2418 // .word 0x6666; rex64; call __tls_get_addr
2419 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2421 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2422 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2424 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2425 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2426 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2427 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2429 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2431 value
-= tls_segment
->memsz();
2432 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
2434 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2436 this->skip_call_tls_get_addr_
= true;
2439 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2442 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2443 const Relocate_info
<64, false>* relinfo
,
2446 const elfcpp::Rela
<64, false>& rela
,
2447 unsigned int r_type
,
2448 elfcpp::Elf_types
<64>::Elf_Addr value
,
2449 unsigned char* view
,
2450 elfcpp::Elf_types
<64>::Elf_Addr address
,
2451 section_size_type view_size
)
2453 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2455 // leaq foo@tlsdesc(%rip), %rax
2456 // ==> movq foo@gottpoff(%rip), %rax
2457 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2458 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2459 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2460 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2462 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2463 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2467 // call *foo@tlscall(%rax)
2469 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2470 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2471 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2472 view
[0] == 0xff && view
[1] == 0x10);
2478 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2481 Target_x86_64::Relocate::tls_desc_gd_to_le(
2482 const Relocate_info
<64, false>* relinfo
,
2484 Output_segment
* tls_segment
,
2485 const elfcpp::Rela
<64, false>& rela
,
2486 unsigned int r_type
,
2487 elfcpp::Elf_types
<64>::Elf_Addr value
,
2488 unsigned char* view
,
2489 section_size_type view_size
)
2491 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2493 // leaq foo@tlsdesc(%rip), %rax
2494 // ==> movq foo@tpoff, %rax
2495 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2496 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2497 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2498 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2501 value
-= tls_segment
->memsz();
2502 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2506 // call *foo@tlscall(%rax)
2508 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2509 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2510 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2511 view
[0] == 0xff && view
[1] == 0x10);
2518 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
2521 const elfcpp::Rela
<64, false>& rela
,
2523 elfcpp::Elf_types
<64>::Elf_Addr
,
2524 unsigned char* view
,
2525 section_size_type view_size
)
2527 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2528 // ... leq foo@dtpoff(%rax),%reg
2529 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2531 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2532 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
2534 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2535 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
2537 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
2539 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2541 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2543 this->skip_call_tls_get_addr_
= true;
2546 // Do a relocation in which we convert a TLS Initial-Exec to a
2550 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
2552 Output_segment
* tls_segment
,
2553 const elfcpp::Rela
<64, false>& rela
,
2555 elfcpp::Elf_types
<64>::Elf_Addr value
,
2556 unsigned char* view
,
2557 section_size_type view_size
)
2559 // We need to examine the opcodes to figure out which instruction we
2562 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
2563 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
2565 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2566 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2568 unsigned char op1
= view
[-3];
2569 unsigned char op2
= view
[-2];
2570 unsigned char op3
= view
[-1];
2571 unsigned char reg
= op3
>> 3;
2579 view
[-1] = 0xc0 | reg
;
2583 // Special handling for %rsp.
2587 view
[-1] = 0xc0 | reg
;
2595 view
[-1] = 0x80 | reg
| (reg
<< 3);
2598 value
-= tls_segment
->memsz();
2599 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2602 // Relocate section data.
2605 Target_x86_64::relocate_section(
2606 const Relocate_info
<64, false>* relinfo
,
2607 unsigned int sh_type
,
2608 const unsigned char* prelocs
,
2610 Output_section
* output_section
,
2611 bool needs_special_offset_handling
,
2612 unsigned char* view
,
2613 elfcpp::Elf_types
<64>::Elf_Addr address
,
2614 section_size_type view_size
,
2615 const Reloc_symbol_changes
* reloc_symbol_changes
)
2617 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2619 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2620 Target_x86_64::Relocate
>(
2626 needs_special_offset_handling
,
2630 reloc_symbol_changes
);
2633 // Return the size of a relocation while scanning during a relocatable
2637 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2638 unsigned int r_type
,
2643 case elfcpp::R_X86_64_NONE
:
2644 case elfcpp::R_386_GNU_VTINHERIT
:
2645 case elfcpp::R_386_GNU_VTENTRY
:
2646 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2647 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2648 case elfcpp::R_X86_64_TLSDESC_CALL
:
2649 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2650 case elfcpp::R_X86_64_DTPOFF32
:
2651 case elfcpp::R_X86_64_DTPOFF64
:
2652 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2653 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2656 case elfcpp::R_X86_64_64
:
2657 case elfcpp::R_X86_64_PC64
:
2658 case elfcpp::R_X86_64_GOTOFF64
:
2659 case elfcpp::R_X86_64_GOTPC64
:
2660 case elfcpp::R_X86_64_PLTOFF64
:
2661 case elfcpp::R_X86_64_GOT64
:
2662 case elfcpp::R_X86_64_GOTPCREL64
:
2663 case elfcpp::R_X86_64_GOTPCREL
:
2664 case elfcpp::R_X86_64_GOTPLT64
:
2667 case elfcpp::R_X86_64_32
:
2668 case elfcpp::R_X86_64_32S
:
2669 case elfcpp::R_X86_64_PC32
:
2670 case elfcpp::R_X86_64_PLT32
:
2671 case elfcpp::R_X86_64_GOTPC32
:
2672 case elfcpp::R_X86_64_GOT32
:
2675 case elfcpp::R_X86_64_16
:
2676 case elfcpp::R_X86_64_PC16
:
2679 case elfcpp::R_X86_64_8
:
2680 case elfcpp::R_X86_64_PC8
:
2683 case elfcpp::R_X86_64_COPY
:
2684 case elfcpp::R_X86_64_GLOB_DAT
:
2685 case elfcpp::R_X86_64_JUMP_SLOT
:
2686 case elfcpp::R_X86_64_RELATIVE
:
2687 // These are outstanding tls relocs, which are unexpected when linking
2688 case elfcpp::R_X86_64_TPOFF64
:
2689 case elfcpp::R_X86_64_DTPMOD64
:
2690 case elfcpp::R_X86_64_TLSDESC
:
2691 object
->error(_("unexpected reloc %u in object file"), r_type
);
2694 case elfcpp::R_X86_64_SIZE32
:
2695 case elfcpp::R_X86_64_SIZE64
:
2697 object
->error(_("unsupported reloc %u against local symbol"), r_type
);
2702 // Scan the relocs during a relocatable link.
2705 Target_x86_64::scan_relocatable_relocs(Symbol_table
* symtab
,
2707 Sized_relobj
<64, false>* object
,
2708 unsigned int data_shndx
,
2709 unsigned int sh_type
,
2710 const unsigned char* prelocs
,
2712 Output_section
* output_section
,
2713 bool needs_special_offset_handling
,
2714 size_t local_symbol_count
,
2715 const unsigned char* plocal_symbols
,
2716 Relocatable_relocs
* rr
)
2718 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2720 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_RELA
,
2721 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
2723 gold::scan_relocatable_relocs
<64, false, elfcpp::SHT_RELA
,
2724 Scan_relocatable_relocs
>(
2732 needs_special_offset_handling
,
2738 // Relocate a section during a relocatable link.
2741 Target_x86_64::relocate_for_relocatable(
2742 const Relocate_info
<64, false>* relinfo
,
2743 unsigned int sh_type
,
2744 const unsigned char* prelocs
,
2746 Output_section
* output_section
,
2747 off_t offset_in_output_section
,
2748 const Relocatable_relocs
* rr
,
2749 unsigned char* view
,
2750 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
2751 section_size_type view_size
,
2752 unsigned char* reloc_view
,
2753 section_size_type reloc_view_size
)
2755 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2757 gold::relocate_for_relocatable
<64, false, elfcpp::SHT_RELA
>(
2762 offset_in_output_section
,
2771 // Return the value to use for a dynamic which requires special
2772 // treatment. This is how we support equality comparisons of function
2773 // pointers across shared library boundaries, as described in the
2774 // processor specific ABI supplement.
2777 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
2779 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
2780 return this->plt_section()->address() + gsym
->plt_offset();
2783 // Return a string used to fill a code section with nops to take up
2784 // the specified length.
2787 Target_x86_64::do_code_fill(section_size_type length
) const
2791 // Build a jmpq instruction to skip over the bytes.
2792 unsigned char jmp
[5];
2794 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
2795 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
2796 + std::string(length
- 5, '\0'));
2799 // Nop sequences of various lengths.
2800 const char nop1
[1] = { 0x90 }; // nop
2801 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
2802 const char nop3
[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
2803 const char nop4
[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
2804 const char nop5
[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
2806 const char nop6
[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
2808 const char nop7
[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
2810 const char nop8
[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
2811 0x00, 0x00, 0x00, 0x00 };
2812 const char nop9
[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
2813 0x00, 0x00, 0x00, 0x00,
2815 const char nop10
[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
2816 0x84, 0x00, 0x00, 0x00,
2818 const char nop11
[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
2819 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2821 const char nop12
[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
2822 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
2823 0x00, 0x00, 0x00, 0x00 };
2824 const char nop13
[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2825 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
2826 0x00, 0x00, 0x00, 0x00,
2828 const char nop14
[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2829 0x66, 0x2e, 0x0f, 0x1f, // data16
2830 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2832 const char nop15
[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2833 0x66, 0x66, 0x2e, 0x0f, // data16; data16
2834 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2837 const char* nops
[16] = {
2839 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
2840 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
2843 return std::string(nops
[length
], length
);
2846 // Return the addend to use for a target specific relocation. The
2847 // only target specific relocation is R_X86_64_TLSDESC for a local
2848 // symbol. We want to set the addend is the offset of the local
2849 // symbol in the TLS segment.
2852 Target_x86_64::do_reloc_addend(void* arg
, unsigned int r_type
,
2855 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
2856 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
2857 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
2858 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
2859 const Symbol_value
<64>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
2860 gold_assert(psymval
->is_tls_symbol());
2861 // The value of a TLS symbol is the offset in the TLS segment.
2862 return psymval
->value(ti
.object
, 0);
2865 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2866 // compiled with -fstack-split. The function calls non-stack-split
2867 // code. We have to change the function so that it always ensures
2868 // that it has enough stack space to run some random function.
2871 Target_x86_64::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
2872 section_offset_type fnoffset
,
2873 section_size_type fnsize
,
2874 unsigned char* view
,
2875 section_size_type view_size
,
2877 std::string
* to
) const
2879 // The function starts with a comparison of the stack pointer and a
2880 // field in the TCB. This is followed by a jump.
2883 if (this->match_view(view
, view_size
, fnoffset
, "\x64\x48\x3b\x24\x25", 5)
2886 // We will call __morestack if the carry flag is set after this
2887 // comparison. We turn the comparison into an stc instruction
2889 view
[fnoffset
] = '\xf9';
2890 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 8);
2892 // lea NN(%rsp),%r10
2893 // lea NN(%rsp),%r11
2894 else if ((this->match_view(view
, view_size
, fnoffset
,
2895 "\x4c\x8d\x94\x24", 4)
2896 || this->match_view(view
, view_size
, fnoffset
,
2897 "\x4c\x8d\x9c\x24", 4))
2900 // This is loading an offset from the stack pointer for a
2901 // comparison. The offset is negative, so we decrease the
2902 // offset by the amount of space we need for the stack. This
2903 // means we will avoid calling __morestack if there happens to
2904 // be plenty of space on the stack already.
2905 unsigned char* pval
= view
+ fnoffset
+ 4;
2906 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
2907 val
-= parameters
->options().split_stack_adjust_size();
2908 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
2912 if (!object
->has_no_split_stack())
2913 object
->error(_("failed to match split-stack sequence at "
2914 "section %u offset %0zx"),
2915 shndx
, static_cast<size_t>(fnoffset
));
2919 // We have to change the function so that it calls
2920 // __morestack_non_split instead of __morestack. The former will
2921 // allocate additional stack space.
2922 *from
= "__morestack";
2923 *to
= "__morestack_non_split";
2926 // The selector for x86_64 object files.
2928 class Target_selector_x86_64
: public Target_selector_freebsd
2931 Target_selector_x86_64()
2932 : Target_selector_freebsd(elfcpp::EM_X86_64
, 64, false, "elf64-x86-64",
2933 "elf64-x86-64-freebsd")
2937 do_instantiate_target()
2938 { return new Target_x86_64(); }
2942 Target_selector_x86_64 target_selector_x86_64
;
2944 } // End anonymous namespace.