1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010 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 // A class to handle the PLT data.
51 class Output_data_plt_x86_64
: public Output_section_data
54 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
56 Output_data_plt_x86_64(Symbol_table
*, Layout
*, Output_data_got
<64, false>*,
59 // Add an entry to the PLT.
61 add_entry(Symbol
* gsym
);
63 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
65 add_local_ifunc_entry(Sized_relobj
<64, false>* relobj
,
66 unsigned int local_sym_index
);
68 // Add the reserved TLSDESC_PLT entry to the PLT.
70 reserve_tlsdesc_entry(unsigned int got_offset
)
71 { this->tlsdesc_got_offset_
= got_offset
; }
73 // Return true if a TLSDESC_PLT entry has been reserved.
75 has_tlsdesc_entry() const
76 { return this->tlsdesc_got_offset_
!= -1U; }
78 // Return the GOT offset for the reserved TLSDESC_PLT entry.
80 get_tlsdesc_got_offset() const
81 { return this->tlsdesc_got_offset_
; }
83 // Return the offset of the reserved TLSDESC_PLT entry.
85 get_tlsdesc_plt_offset() const
86 { return (this->count_
+ 1) * plt_entry_size
; }
88 // Return the .rela.plt section data.
91 { return this->rel_
; }
93 // Return where the TLSDESC relocations should go.
95 rela_tlsdesc(Layout
*);
97 // Return the number of PLT entries.
100 { return this->count_
; }
102 // Return the offset of the first non-reserved PLT entry.
104 first_plt_entry_offset()
105 { return plt_entry_size
; }
107 // Return the size of a PLT entry.
110 { return plt_entry_size
; }
114 do_adjust_output_section(Output_section
* os
);
116 // Write to a map file.
118 do_print_to_mapfile(Mapfile
* mapfile
) const
119 { mapfile
->print_output_data(this, _("** PLT")); }
122 // The size of an entry in the PLT.
123 static const int plt_entry_size
= 16;
125 // The first entry in the PLT.
126 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
127 // procedure linkage table for both programs and shared objects."
128 static unsigned char first_plt_entry
[plt_entry_size
];
130 // Other entries in the PLT for an executable.
131 static unsigned char plt_entry
[plt_entry_size
];
133 // The reserved TLSDESC entry in the PLT for an executable.
134 static unsigned char tlsdesc_plt_entry
[plt_entry_size
];
136 // Set the final size.
138 set_final_data_size();
140 // Write out the PLT data.
142 do_write(Output_file
*);
144 // The reloc section.
146 // The TLSDESC relocs, if necessary. These must follow the regular
148 Reloc_section
* tlsdesc_rel_
;
150 Output_data_got
<64, false>* got_
;
151 // The .got.plt section.
152 Output_data_space
* got_plt_
;
153 // The number of PLT entries.
155 // Offset of the reserved TLSDESC_GOT entry when needed.
156 unsigned int tlsdesc_got_offset_
;
159 // The x86_64 target class.
161 // http://www.x86-64.org/documentation/abi.pdf
162 // TLS info comes from
163 // http://people.redhat.com/drepper/tls.pdf
164 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
166 class Target_x86_64
: public Target_freebsd
<64, false>
169 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
170 // uses only Elf64_Rela relocation entries with explicit addends."
171 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false> Reloc_section
;
174 : Target_freebsd
<64, false>(&x86_64_info
),
175 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_tlsdesc_(NULL
),
176 global_offset_table_(NULL
), rela_dyn_(NULL
),
177 copy_relocs_(elfcpp::R_X86_64_COPY
), dynbss_(NULL
),
178 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
179 tls_base_symbol_defined_(false)
182 // This function should be defined in targets that can use relocation
183 // types to determine (implemented in local_reloc_may_be_function_pointer
184 // and global_reloc_may_be_function_pointer)
185 // if a function's pointer is taken. ICF uses this in safe mode to only
186 // fold those functions whose pointer is defintely not taken. For x86_64
187 // pie binaries, safe ICF cannot be done by looking at relocation types.
189 can_check_for_function_pointers() const
190 { return !parameters
->options().pie(); }
192 // Hook for a new output section.
194 do_new_output_section(Output_section
*) const;
196 // Scan the relocations to look for symbol adjustments.
198 gc_process_relocs(Symbol_table
* symtab
,
200 Sized_relobj
<64, false>* object
,
201 unsigned int data_shndx
,
202 unsigned int sh_type
,
203 const unsigned char* prelocs
,
205 Output_section
* output_section
,
206 bool needs_special_offset_handling
,
207 size_t local_symbol_count
,
208 const unsigned char* plocal_symbols
);
210 // Scan the relocations to look for symbol adjustments.
212 scan_relocs(Symbol_table
* symtab
,
214 Sized_relobj
<64, false>* object
,
215 unsigned int data_shndx
,
216 unsigned int sh_type
,
217 const unsigned char* prelocs
,
219 Output_section
* output_section
,
220 bool needs_special_offset_handling
,
221 size_t local_symbol_count
,
222 const unsigned char* plocal_symbols
);
224 // Finalize the sections.
226 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
228 // Return the value to use for a dynamic which requires special
231 do_dynsym_value(const Symbol
*) const;
233 // Relocate a section.
235 relocate_section(const Relocate_info
<64, false>*,
236 unsigned int sh_type
,
237 const unsigned char* prelocs
,
239 Output_section
* output_section
,
240 bool needs_special_offset_handling
,
242 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
243 section_size_type view_size
,
244 const Reloc_symbol_changes
*);
246 // Scan the relocs during a relocatable link.
248 scan_relocatable_relocs(Symbol_table
* symtab
,
250 Sized_relobj
<64, false>* object
,
251 unsigned int data_shndx
,
252 unsigned int sh_type
,
253 const unsigned char* prelocs
,
255 Output_section
* output_section
,
256 bool needs_special_offset_handling
,
257 size_t local_symbol_count
,
258 const unsigned char* plocal_symbols
,
259 Relocatable_relocs
*);
261 // Relocate a section during a relocatable link.
263 relocate_for_relocatable(const Relocate_info
<64, false>*,
264 unsigned int sh_type
,
265 const unsigned char* prelocs
,
267 Output_section
* output_section
,
268 off_t offset_in_output_section
,
269 const Relocatable_relocs
*,
271 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
272 section_size_type view_size
,
273 unsigned char* reloc_view
,
274 section_size_type reloc_view_size
);
276 // Return a string used to fill a code section with nops.
278 do_code_fill(section_size_type length
) const;
280 // Return whether SYM is defined by the ABI.
282 do_is_defined_by_abi(const Symbol
* sym
) const
283 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
285 // Return the symbol index to use for a target specific relocation.
286 // The only target specific relocation is R_X86_64_TLSDESC for a
287 // local symbol, which is an absolute reloc.
289 do_reloc_symbol_index(void*, unsigned int r_type
) const
291 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
295 // Return the addend to use for a target specific relocation.
297 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
299 // Return the PLT section.
301 do_plt_section_for_global(const Symbol
*) const
302 { return this->plt_section(); }
305 do_plt_section_for_local(const Relobj
*, unsigned int) const
306 { return this->plt_section(); }
308 // Adjust -fstack-split code which calls non-stack-split code.
310 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
311 section_offset_type fnoffset
, section_size_type fnsize
,
312 unsigned char* view
, section_size_type view_size
,
313 std::string
* from
, std::string
* to
) const;
315 // Return the size of the GOT section.
319 gold_assert(this->got_
!= NULL
);
320 return this->got_
->data_size();
323 // Return the number of entries in the GOT.
325 got_entry_count() const
327 if (this->got_
== NULL
)
329 return this->got_size() / 8;
332 // Return the number of entries in the PLT.
334 plt_entry_count() const;
336 // Return the offset of the first non-reserved PLT entry.
338 first_plt_entry_offset() const;
340 // Return the size of each PLT entry.
342 plt_entry_size() const;
344 // Add a new reloc argument, returning the index in the vector.
346 add_tlsdesc_info(Sized_relobj
<64, false>* object
, unsigned int r_sym
)
348 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
349 return this->tlsdesc_reloc_info_
.size() - 1;
353 // The class which scans relocations.
358 : issued_non_pic_error_(false)
362 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
363 Sized_relobj
<64, false>* object
,
364 unsigned int data_shndx
,
365 Output_section
* output_section
,
366 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
367 const elfcpp::Sym
<64, false>& lsym
);
370 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
371 Sized_relobj
<64, false>* object
,
372 unsigned int data_shndx
,
373 Output_section
* output_section
,
374 const elfcpp::Rela
<64, false>& reloc
, unsigned int r_type
,
378 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
379 Target_x86_64
* target
,
380 Sized_relobj
<64, false>* object
,
381 unsigned int data_shndx
,
382 Output_section
* output_section
,
383 const elfcpp::Rela
<64, false>& reloc
,
385 const elfcpp::Sym
<64, false>& lsym
);
388 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
389 Target_x86_64
* target
,
390 Sized_relobj
<64, false>* object
,
391 unsigned int data_shndx
,
392 Output_section
* output_section
,
393 const elfcpp::Rela
<64, false>& reloc
,
399 unsupported_reloc_local(Sized_relobj
<64, false>*, unsigned int r_type
);
402 unsupported_reloc_global(Sized_relobj
<64, false>*, unsigned int r_type
,
406 check_non_pic(Relobj
*, unsigned int r_type
);
409 possible_function_pointer_reloc(unsigned int r_type
);
412 reloc_needs_plt_for_ifunc(Sized_relobj
<64, false>*, unsigned int r_type
);
414 // Whether we have issued an error about a non-PIC compilation.
415 bool issued_non_pic_error_
;
418 // The class which implements relocation.
423 : skip_call_tls_get_addr_(false)
428 if (this->skip_call_tls_get_addr_
)
430 // FIXME: This needs to specify the location somehow.
431 gold_error(_("missing expected TLS relocation"));
435 // Do a relocation. Return false if the caller should not issue
436 // any warnings about this relocation.
438 relocate(const Relocate_info
<64, false>*, Target_x86_64
*, Output_section
*,
439 size_t relnum
, const elfcpp::Rela
<64, false>&,
440 unsigned int r_type
, const Sized_symbol
<64>*,
441 const Symbol_value
<64>*,
442 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
446 // Do a TLS relocation.
448 relocate_tls(const Relocate_info
<64, false>*, Target_x86_64
*,
449 size_t relnum
, const elfcpp::Rela
<64, false>&,
450 unsigned int r_type
, const Sized_symbol
<64>*,
451 const Symbol_value
<64>*,
452 unsigned char*, elfcpp::Elf_types
<64>::Elf_Addr
,
455 // Do a TLS General-Dynamic to Initial-Exec transition.
457 tls_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
458 Output_segment
* tls_segment
,
459 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
460 elfcpp::Elf_types
<64>::Elf_Addr value
,
462 elfcpp::Elf_types
<64>::Elf_Addr
,
463 section_size_type view_size
);
465 // Do a TLS General-Dynamic to Local-Exec transition.
467 tls_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
468 Output_segment
* tls_segment
,
469 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
470 elfcpp::Elf_types
<64>::Elf_Addr value
,
472 section_size_type view_size
);
474 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
476 tls_desc_gd_to_ie(const Relocate_info
<64, false>*, size_t relnum
,
477 Output_segment
* tls_segment
,
478 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
479 elfcpp::Elf_types
<64>::Elf_Addr value
,
481 elfcpp::Elf_types
<64>::Elf_Addr
,
482 section_size_type view_size
);
484 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
486 tls_desc_gd_to_le(const Relocate_info
<64, false>*, size_t relnum
,
487 Output_segment
* tls_segment
,
488 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
489 elfcpp::Elf_types
<64>::Elf_Addr value
,
491 section_size_type view_size
);
493 // Do a TLS Local-Dynamic to Local-Exec transition.
495 tls_ld_to_le(const Relocate_info
<64, false>*, size_t relnum
,
496 Output_segment
* tls_segment
,
497 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
498 elfcpp::Elf_types
<64>::Elf_Addr value
,
500 section_size_type view_size
);
502 // Do a TLS Initial-Exec to Local-Exec transition.
504 tls_ie_to_le(const Relocate_info
<64, false>*, size_t relnum
,
505 Output_segment
* tls_segment
,
506 const elfcpp::Rela
<64, false>&, unsigned int r_type
,
507 elfcpp::Elf_types
<64>::Elf_Addr value
,
509 section_size_type view_size
);
511 // This is set if we should skip the next reloc, which should be a
512 // PLT32 reloc against ___tls_get_addr.
513 bool skip_call_tls_get_addr_
;
516 // A class which returns the size required for a relocation type,
517 // used while scanning relocs during a relocatable link.
518 class Relocatable_size_for_reloc
522 get_size_for_reloc(unsigned int, Relobj
*);
525 // Adjust TLS relocation type based on the options and whether this
526 // is a local symbol.
527 static tls::Tls_optimization
528 optimize_tls_reloc(bool is_final
, int r_type
);
530 // Get the GOT section, creating it if necessary.
531 Output_data_got
<64, false>*
532 got_section(Symbol_table
*, Layout
*);
534 // Get the GOT PLT section.
536 got_plt_section() const
538 gold_assert(this->got_plt_
!= NULL
);
539 return this->got_plt_
;
542 // Get the GOT section for TLSDESC entries.
543 Output_data_got
<64, false>*
544 got_tlsdesc_section() const
546 gold_assert(this->got_tlsdesc_
!= NULL
);
547 return this->got_tlsdesc_
;
550 // Create the PLT section.
552 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
554 // Create a PLT entry for a global symbol.
556 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
558 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
560 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
561 Sized_relobj
<64, false>* relobj
,
562 unsigned int local_sym_index
);
564 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
566 define_tls_base_symbol(Symbol_table
*, Layout
*);
568 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
570 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
572 // Create a GOT entry for the TLS module index.
574 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
575 Sized_relobj
<64, false>* object
);
577 // Get the PLT section.
578 Output_data_plt_x86_64
*
581 gold_assert(this->plt_
!= NULL
);
585 // Get the dynamic reloc section, creating it if necessary.
587 rela_dyn_section(Layout
*);
589 // Get the section to use for TLSDESC relocations.
591 rela_tlsdesc_section(Layout
*) const;
593 // Add a potential copy relocation.
595 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
596 Sized_relobj
<64, false>* object
,
597 unsigned int shndx
, Output_section
* output_section
,
598 Symbol
* sym
, const elfcpp::Rela
<64, false>& reloc
)
600 this->copy_relocs_
.copy_reloc(symtab
, layout
,
601 symtab
->get_sized_symbol
<64>(sym
),
602 object
, shndx
, output_section
,
603 reloc
, this->rela_dyn_section(layout
));
606 // Information about this specific target which we pass to the
607 // general Target structure.
608 static const Target::Target_info x86_64_info
;
610 // The types of GOT entries needed for this platform.
611 // These values are exposed to the ABI in an incremental link.
612 // Do not renumber existing values without changing the version
613 // number of the .gnu_incremental_inputs section.
616 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
617 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
618 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
619 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
622 // This type is used as the argument to the target specific
623 // relocation routines. The only target specific reloc is
624 // R_X86_64_TLSDESC against a local symbol.
627 Tlsdesc_info(Sized_relobj
<64, false>* a_object
, unsigned int a_r_sym
)
628 : object(a_object
), r_sym(a_r_sym
)
631 // The object in which the local symbol is defined.
632 Sized_relobj
<64, false>* object
;
633 // The local symbol index in the object.
638 Output_data_got
<64, false>* got_
;
640 Output_data_plt_x86_64
* plt_
;
641 // The GOT PLT section.
642 Output_data_space
* got_plt_
;
643 // The GOT section for TLSDESC relocations.
644 Output_data_got
<64, false>* got_tlsdesc_
;
645 // The _GLOBAL_OFFSET_TABLE_ symbol.
646 Symbol
* global_offset_table_
;
647 // The dynamic reloc section.
648 Reloc_section
* rela_dyn_
;
649 // Relocs saved to avoid a COPY reloc.
650 Copy_relocs
<elfcpp::SHT_RELA
, 64, false> copy_relocs_
;
651 // Space for variables copied with a COPY reloc.
652 Output_data_space
* dynbss_
;
653 // Offset of the GOT entry for the TLS module index.
654 unsigned int got_mod_index_offset_
;
655 // We handle R_X86_64_TLSDESC against a local symbol as a target
656 // specific relocation. Here we store the object and local symbol
657 // index for the relocation.
658 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
659 // True if the _TLS_MODULE_BASE_ symbol has been defined.
660 bool tls_base_symbol_defined_
;
663 const Target::Target_info
Target_x86_64::x86_64_info
=
666 false, // is_big_endian
667 elfcpp::EM_X86_64
, // machine_code
668 false, // has_make_symbol
669 false, // has_resolve
670 true, // has_code_fill
671 true, // is_default_stack_executable
673 "/lib/ld64.so.1", // program interpreter
674 0x400000, // default_text_segment_address
675 0x1000, // abi_pagesize (overridable by -z max-page-size)
676 0x1000, // common_pagesize (overridable by -z common-page-size)
677 elfcpp::SHN_UNDEF
, // small_common_shndx
678 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
679 0, // small_common_section_flags
680 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
681 NULL
, // attributes_section
682 NULL
// attributes_vendor
685 // This is called when a new output section is created. This is where
686 // we handle the SHF_X86_64_LARGE.
689 Target_x86_64::do_new_output_section(Output_section
* os
) const
691 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
692 os
->set_is_large_section();
695 // Get the GOT section, creating it if necessary.
697 Output_data_got
<64, false>*
698 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
700 if (this->got_
== NULL
)
702 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
704 this->got_
= new Output_data_got
<64, false>();
706 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
708 | elfcpp::SHF_WRITE
),
709 this->got_
, ORDER_RELRO_LAST
,
712 this->got_plt_
= new Output_data_space(8, "** GOT PLT");
713 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
715 | elfcpp::SHF_WRITE
),
716 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
719 // The first three entries are reserved.
720 this->got_plt_
->set_current_data_size(3 * 8);
722 // Those bytes can go into the relro segment.
723 layout
->increase_relro(3 * 8);
725 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
726 this->global_offset_table_
=
727 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
728 Symbol_table::PREDEFINED
,
730 0, 0, elfcpp::STT_OBJECT
,
732 elfcpp::STV_HIDDEN
, 0,
735 // If there are any TLSDESC relocations, they get GOT entries in
736 // .got.plt after the jump slot entries.
737 this->got_tlsdesc_
= new Output_data_got
<64, false>();
738 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
740 | elfcpp::SHF_WRITE
),
742 ORDER_NON_RELRO_FIRST
, false);
748 // Get the dynamic reloc section, creating it if necessary.
750 Target_x86_64::Reloc_section
*
751 Target_x86_64::rela_dyn_section(Layout
* layout
)
753 if (this->rela_dyn_
== NULL
)
755 gold_assert(layout
!= NULL
);
756 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
757 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
758 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
759 ORDER_DYNAMIC_RELOCS
, false);
761 return this->rela_dyn_
;
764 // Create the PLT section. The ordinary .got section is an argument,
765 // since we need to refer to the start. We also create our own .got
766 // section just for PLT entries.
768 Output_data_plt_x86_64::Output_data_plt_x86_64(Symbol_table
* symtab
,
770 Output_data_got
<64, false>* got
,
771 Output_data_space
* got_plt
)
772 : Output_section_data(8), tlsdesc_rel_(NULL
), got_(got
), got_plt_(got_plt
),
773 count_(0), tlsdesc_got_offset_(-1U)
775 this->rel_
= new Reloc_section(false);
776 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
777 elfcpp::SHF_ALLOC
, this->rel_
,
778 ORDER_DYNAMIC_PLT_RELOCS
, false);
780 if (parameters
->doing_static_link())
782 // A statically linked executable will only have a .rela.plt
783 // section to hold R_X86_64_IRELATIVE relocs for STT_GNU_IFUNC
784 // symbols. The library will use these symbols to locate the
785 // IRELATIVE relocs at program startup time.
786 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
787 Symbol_table::PREDEFINED
,
788 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
789 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
791 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
792 Symbol_table::PREDEFINED
,
793 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
794 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
800 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
802 os
->set_entsize(plt_entry_size
);
805 // Add an entry to the PLT.
808 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
810 gold_assert(!gsym
->has_plt_offset());
812 // Note that when setting the PLT offset we skip the initial
813 // reserved PLT entry.
814 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
818 section_offset_type got_offset
= this->got_plt_
->current_data_size();
820 // Every PLT entry needs a GOT entry which points back to the PLT
821 // entry (this will be changed by the dynamic linker, normally
822 // lazily when the function is called).
823 this->got_plt_
->set_current_data_size(got_offset
+ 8);
825 // Every PLT entry needs a reloc.
826 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
827 && gsym
->can_use_relative_reloc(false))
828 this->rel_
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
829 this->got_plt_
, got_offset
, 0);
832 gsym
->set_needs_dynsym_entry();
833 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
837 // Note that we don't need to save the symbol. The contents of the
838 // PLT are independent of which symbols are used. The symbols only
839 // appear in the relocations.
842 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
846 Output_data_plt_x86_64::add_local_ifunc_entry(Sized_relobj
<64, false>* relobj
,
847 unsigned int local_sym_index
)
849 unsigned int plt_offset
= (this->count_
+ 1) * plt_entry_size
;
852 section_offset_type got_offset
= this->got_plt_
->current_data_size();
854 // Every PLT entry needs a GOT entry which points back to the PLT
856 this->got_plt_
->set_current_data_size(got_offset
+ 8);
858 // Every PLT entry needs a reloc.
859 this->rel_
->add_symbolless_local_addend(relobj
, local_sym_index
,
860 elfcpp::R_X86_64_IRELATIVE
,
861 this->got_plt_
, got_offset
, 0);
866 // Return where the TLSDESC relocations should go, creating it if
867 // necessary. These follow the JUMP_SLOT relocations.
869 Output_data_plt_x86_64::Reloc_section
*
870 Output_data_plt_x86_64::rela_tlsdesc(Layout
* layout
)
872 if (this->tlsdesc_rel_
== NULL
)
874 this->tlsdesc_rel_
= new Reloc_section(false);
875 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
876 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
877 ORDER_DYNAMIC_PLT_RELOCS
, false);
878 gold_assert(this->tlsdesc_rel_
->output_section() ==
879 this->rel_
->output_section());
881 return this->tlsdesc_rel_
;
884 // Set the final size.
886 Output_data_plt_x86_64::set_final_data_size()
888 unsigned int count
= this->count_
;
889 if (this->has_tlsdesc_entry())
891 this->set_data_size((count
+ 1) * plt_entry_size
);
894 // The first entry in the PLT for an executable.
896 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
898 // From AMD64 ABI Draft 0.98, page 76
899 0xff, 0x35, // pushq contents of memory address
900 0, 0, 0, 0, // replaced with address of .got + 8
901 0xff, 0x25, // jmp indirect
902 0, 0, 0, 0, // replaced with address of .got + 16
903 0x90, 0x90, 0x90, 0x90 // noop (x4)
906 // Subsequent entries in the PLT for an executable.
908 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
910 // From AMD64 ABI Draft 0.98, page 76
911 0xff, 0x25, // jmpq indirect
912 0, 0, 0, 0, // replaced with address of symbol in .got
913 0x68, // pushq immediate
914 0, 0, 0, 0, // replaced with offset into relocation table
915 0xe9, // jmpq relative
916 0, 0, 0, 0 // replaced with offset to start of .plt
919 // The reserved TLSDESC entry in the PLT for an executable.
921 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry
[plt_entry_size
] =
923 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
924 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
925 0xff, 0x35, // pushq x(%rip)
926 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
927 0xff, 0x25, // jmpq *y(%rip)
928 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
933 // Write out the PLT. This uses the hand-coded instructions above,
934 // and adjusts them as needed. This is specified by the AMD64 ABI.
937 Output_data_plt_x86_64::do_write(Output_file
* of
)
939 const off_t offset
= this->offset();
940 const section_size_type oview_size
=
941 convert_to_section_size_type(this->data_size());
942 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
944 const off_t got_file_offset
= this->got_plt_
->offset();
945 const section_size_type got_size
=
946 convert_to_section_size_type(this->got_plt_
->data_size());
947 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
950 unsigned char* pov
= oview
;
952 // The base address of the .plt section.
953 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
954 // The base address of the .got section.
955 elfcpp::Elf_types
<64>::Elf_Addr got_base
= this->got_
->address();
956 // The base address of the PLT portion of the .got section,
957 // which is where the GOT pointer will point, and where the
958 // three reserved GOT entries are located.
959 elfcpp::Elf_types
<64>::Elf_Addr got_address
= this->got_plt_
->address();
961 memcpy(pov
, first_plt_entry
, plt_entry_size
);
962 // We do a jmp relative to the PC at the end of this instruction.
963 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
965 - (plt_address
+ 6)));
966 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
968 - (plt_address
+ 12)));
969 pov
+= plt_entry_size
;
971 unsigned char* got_pov
= got_view
;
973 memset(got_pov
, 0, 24);
976 unsigned int plt_offset
= plt_entry_size
;
977 unsigned int got_offset
= 24;
978 const unsigned int count
= this->count_
;
979 for (unsigned int plt_index
= 0;
982 pov
+= plt_entry_size
,
984 plt_offset
+= plt_entry_size
,
987 // Set and adjust the PLT entry itself.
988 memcpy(pov
, plt_entry
, plt_entry_size
);
989 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
990 (got_address
+ got_offset
991 - (plt_address
+ plt_offset
994 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
995 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
996 - (plt_offset
+ plt_entry_size
));
998 // Set the entry in the GOT.
999 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
1002 if (this->has_tlsdesc_entry())
1004 // Set and adjust the reserved TLSDESC PLT entry.
1005 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
1006 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1007 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1009 - (plt_address
+ plt_offset
1011 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
1013 + tlsdesc_got_offset
1014 - (plt_address
+ plt_offset
1016 pov
+= plt_entry_size
;
1019 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1020 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1022 of
->write_output_view(offset
, oview_size
, oview
);
1023 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1026 // Create the PLT section.
1029 Target_x86_64::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1031 if (this->plt_
== NULL
)
1033 // Create the GOT sections first.
1034 this->got_section(symtab
, layout
);
1036 this->plt_
= new Output_data_plt_x86_64(symtab
, layout
, this->got_
,
1038 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1040 | elfcpp::SHF_EXECINSTR
),
1041 this->plt_
, ORDER_PLT
, false);
1043 // Make the sh_info field of .rela.plt point to .plt.
1044 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1045 rela_plt_os
->set_info_section(this->plt_
->output_section());
1049 // Return the section for TLSDESC relocations.
1051 Target_x86_64::Reloc_section
*
1052 Target_x86_64::rela_tlsdesc_section(Layout
* layout
) const
1054 return this->plt_section()->rela_tlsdesc(layout
);
1057 // Create a PLT entry for a global symbol.
1060 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1063 if (gsym
->has_plt_offset())
1066 if (this->plt_
== NULL
)
1067 this->make_plt_section(symtab
, layout
);
1069 this->plt_
->add_entry(gsym
);
1072 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1075 Target_x86_64::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1076 Sized_relobj
<64, false>* relobj
,
1077 unsigned int local_sym_index
)
1079 if (relobj
->local_has_plt_offset(local_sym_index
))
1081 if (this->plt_
== NULL
)
1082 this->make_plt_section(symtab
, layout
);
1083 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(relobj
,
1085 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1088 // Return the number of entries in the PLT.
1091 Target_x86_64::plt_entry_count() const
1093 if (this->plt_
== NULL
)
1095 return this->plt_
->entry_count();
1098 // Return the offset of the first non-reserved PLT entry.
1101 Target_x86_64::first_plt_entry_offset() const
1103 return Output_data_plt_x86_64::first_plt_entry_offset();
1106 // Return the size of each PLT entry.
1109 Target_x86_64::plt_entry_size() const
1111 return Output_data_plt_x86_64::get_plt_entry_size();
1114 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1117 Target_x86_64::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1119 if (this->tls_base_symbol_defined_
)
1122 Output_segment
* tls_segment
= layout
->tls_segment();
1123 if (tls_segment
!= NULL
)
1125 bool is_exec
= parameters
->options().output_is_executable();
1126 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1127 Symbol_table::PREDEFINED
,
1131 elfcpp::STV_HIDDEN
, 0,
1133 ? Symbol::SEGMENT_END
1134 : Symbol::SEGMENT_START
),
1137 this->tls_base_symbol_defined_
= true;
1140 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1143 Target_x86_64::reserve_tlsdesc_entries(Symbol_table
* symtab
,
1146 if (this->plt_
== NULL
)
1147 this->make_plt_section(symtab
, layout
);
1149 if (!this->plt_
->has_tlsdesc_entry())
1151 // Allocate the TLSDESC_GOT entry.
1152 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
1153 unsigned int got_offset
= got
->add_constant(0);
1155 // Allocate the TLSDESC_PLT entry.
1156 this->plt_
->reserve_tlsdesc_entry(got_offset
);
1160 // Create a GOT entry for the TLS module index.
1163 Target_x86_64::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1164 Sized_relobj
<64, false>* object
)
1166 if (this->got_mod_index_offset_
== -1U)
1168 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1169 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1170 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
1171 unsigned int got_offset
= got
->add_constant(0);
1172 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
1174 got
->add_constant(0);
1175 this->got_mod_index_offset_
= got_offset
;
1177 return this->got_mod_index_offset_
;
1180 // Optimize the TLS relocation type based on what we know about the
1181 // symbol. IS_FINAL is true if the final address of this symbol is
1182 // known at link time.
1184 tls::Tls_optimization
1185 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
1187 // If we are generating a shared library, then we can't do anything
1189 if (parameters
->options().shared())
1190 return tls::TLSOPT_NONE
;
1194 case elfcpp::R_X86_64_TLSGD
:
1195 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1196 case elfcpp::R_X86_64_TLSDESC_CALL
:
1197 // These are General-Dynamic which permits fully general TLS
1198 // access. Since we know that we are generating an executable,
1199 // we can convert this to Initial-Exec. If we also know that
1200 // this is a local symbol, we can further switch to Local-Exec.
1202 return tls::TLSOPT_TO_LE
;
1203 return tls::TLSOPT_TO_IE
;
1205 case elfcpp::R_X86_64_TLSLD
:
1206 // This is Local-Dynamic, which refers to a local symbol in the
1207 // dynamic TLS block. Since we know that we generating an
1208 // executable, we can switch to Local-Exec.
1209 return tls::TLSOPT_TO_LE
;
1211 case elfcpp::R_X86_64_DTPOFF32
:
1212 case elfcpp::R_X86_64_DTPOFF64
:
1213 // Another Local-Dynamic reloc.
1214 return tls::TLSOPT_TO_LE
;
1216 case elfcpp::R_X86_64_GOTTPOFF
:
1217 // These are Initial-Exec relocs which get the thread offset
1218 // from the GOT. If we know that we are linking against the
1219 // local symbol, we can switch to Local-Exec, which links the
1220 // thread offset into the instruction.
1222 return tls::TLSOPT_TO_LE
;
1223 return tls::TLSOPT_NONE
;
1225 case elfcpp::R_X86_64_TPOFF32
:
1226 // When we already have Local-Exec, there is nothing further we
1228 return tls::TLSOPT_NONE
;
1235 // Report an unsupported relocation against a local symbol.
1238 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
1239 unsigned int r_type
)
1241 gold_error(_("%s: unsupported reloc %u against local symbol"),
1242 object
->name().c_str(), r_type
);
1245 // We are about to emit a dynamic relocation of type R_TYPE. If the
1246 // dynamic linker does not support it, issue an error. The GNU linker
1247 // only issues a non-PIC error for an allocated read-only section.
1248 // Here we know the section is allocated, but we don't know that it is
1249 // read-only. But we check for all the relocation types which the
1250 // glibc dynamic linker supports, so it seems appropriate to issue an
1251 // error even if the section is not read-only.
1254 Target_x86_64::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
)
1258 // These are the relocation types supported by glibc for x86_64.
1259 case elfcpp::R_X86_64_RELATIVE
:
1260 case elfcpp::R_X86_64_IRELATIVE
:
1261 case elfcpp::R_X86_64_GLOB_DAT
:
1262 case elfcpp::R_X86_64_JUMP_SLOT
:
1263 case elfcpp::R_X86_64_DTPMOD64
:
1264 case elfcpp::R_X86_64_DTPOFF64
:
1265 case elfcpp::R_X86_64_TPOFF64
:
1266 case elfcpp::R_X86_64_64
:
1267 case elfcpp::R_X86_64_32
:
1268 case elfcpp::R_X86_64_PC32
:
1269 case elfcpp::R_X86_64_COPY
:
1273 // This prevents us from issuing more than one error per reloc
1274 // section. But we can still wind up issuing more than one
1275 // error per object file.
1276 if (this->issued_non_pic_error_
)
1278 gold_assert(parameters
->options().output_is_position_independent());
1279 object
->error(_("requires unsupported dynamic reloc; "
1280 "recompile with -fPIC"));
1281 this->issued_non_pic_error_
= true;
1284 case elfcpp::R_X86_64_NONE
:
1289 // Return whether we need to make a PLT entry for a relocation of the
1290 // given type against a STT_GNU_IFUNC symbol.
1293 Target_x86_64::Scan::reloc_needs_plt_for_ifunc(Sized_relobj
<64, false>* object
,
1294 unsigned int r_type
)
1298 case elfcpp::R_X86_64_NONE
:
1299 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1300 case elfcpp::R_X86_64_GNU_VTENTRY
:
1303 case elfcpp::R_X86_64_64
:
1304 case elfcpp::R_X86_64_32
:
1305 case elfcpp::R_X86_64_32S
:
1306 case elfcpp::R_X86_64_16
:
1307 case elfcpp::R_X86_64_8
:
1308 case elfcpp::R_X86_64_PC64
:
1309 case elfcpp::R_X86_64_PC32
:
1310 case elfcpp::R_X86_64_PC16
:
1311 case elfcpp::R_X86_64_PC8
:
1312 case elfcpp::R_X86_64_PLT32
:
1313 case elfcpp::R_X86_64_GOTPC32
:
1314 case elfcpp::R_X86_64_GOTOFF64
:
1315 case elfcpp::R_X86_64_GOTPC64
:
1316 case elfcpp::R_X86_64_PLTOFF64
:
1317 case elfcpp::R_X86_64_GOT64
:
1318 case elfcpp::R_X86_64_GOT32
:
1319 case elfcpp::R_X86_64_GOTPCREL64
:
1320 case elfcpp::R_X86_64_GOTPCREL
:
1321 case elfcpp::R_X86_64_GOTPLT64
:
1324 case elfcpp::R_X86_64_COPY
:
1325 case elfcpp::R_X86_64_GLOB_DAT
:
1326 case elfcpp::R_X86_64_JUMP_SLOT
:
1327 case elfcpp::R_X86_64_RELATIVE
:
1328 case elfcpp::R_X86_64_IRELATIVE
:
1329 case elfcpp::R_X86_64_TPOFF64
:
1330 case elfcpp::R_X86_64_DTPMOD64
:
1331 case elfcpp::R_X86_64_TLSDESC
:
1332 // We will give an error later.
1335 case elfcpp::R_X86_64_TLSGD
:
1336 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1337 case elfcpp::R_X86_64_TLSDESC_CALL
:
1338 case elfcpp::R_X86_64_TLSLD
:
1339 case elfcpp::R_X86_64_DTPOFF32
:
1340 case elfcpp::R_X86_64_DTPOFF64
:
1341 case elfcpp::R_X86_64_GOTTPOFF
:
1342 case elfcpp::R_X86_64_TPOFF32
:
1343 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1344 object
->name().c_str(), r_type
);
1347 case elfcpp::R_X86_64_SIZE32
:
1348 case elfcpp::R_X86_64_SIZE64
:
1350 // We will give an error later.
1355 // Scan a relocation for a local symbol.
1358 Target_x86_64::Scan::local(Symbol_table
* symtab
,
1360 Target_x86_64
* target
,
1361 Sized_relobj
<64, false>* object
,
1362 unsigned int data_shndx
,
1363 Output_section
* output_section
,
1364 const elfcpp::Rela
<64, false>& reloc
,
1365 unsigned int r_type
,
1366 const elfcpp::Sym
<64, false>& lsym
)
1368 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1369 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1370 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1372 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1373 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1378 case elfcpp::R_X86_64_NONE
:
1379 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1380 case elfcpp::R_X86_64_GNU_VTENTRY
:
1383 case elfcpp::R_X86_64_64
:
1384 // If building a shared library (or a position-independent
1385 // executable), we need to create a dynamic relocation for this
1386 // location. The relocation applied at link time will apply the
1387 // link-time value, so we flag the location with an
1388 // R_X86_64_RELATIVE relocation so the dynamic loader can
1389 // relocate it easily.
1390 if (parameters
->options().output_is_position_independent())
1392 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1393 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1394 rela_dyn
->add_local_relative(object
, r_sym
,
1395 elfcpp::R_X86_64_RELATIVE
,
1396 output_section
, data_shndx
,
1397 reloc
.get_r_offset(),
1398 reloc
.get_r_addend());
1402 case elfcpp::R_X86_64_32
:
1403 case elfcpp::R_X86_64_32S
:
1404 case elfcpp::R_X86_64_16
:
1405 case elfcpp::R_X86_64_8
:
1406 // If building a shared library (or a position-independent
1407 // executable), we need to create a dynamic relocation for this
1408 // location. We can't use an R_X86_64_RELATIVE relocation
1409 // because that is always a 64-bit relocation.
1410 if (parameters
->options().output_is_position_independent())
1412 this->check_non_pic(object
, r_type
);
1414 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1415 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1416 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1417 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1418 data_shndx
, reloc
.get_r_offset(),
1419 reloc
.get_r_addend());
1422 gold_assert(lsym
.get_st_value() == 0);
1423 unsigned int shndx
= lsym
.get_st_shndx();
1425 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1428 object
->error(_("section symbol %u has bad shndx %u"),
1431 rela_dyn
->add_local_section(object
, shndx
,
1432 r_type
, output_section
,
1433 data_shndx
, reloc
.get_r_offset(),
1434 reloc
.get_r_addend());
1439 case elfcpp::R_X86_64_PC64
:
1440 case elfcpp::R_X86_64_PC32
:
1441 case elfcpp::R_X86_64_PC16
:
1442 case elfcpp::R_X86_64_PC8
:
1445 case elfcpp::R_X86_64_PLT32
:
1446 // Since we know this is a local symbol, we can handle this as a
1450 case elfcpp::R_X86_64_GOTPC32
:
1451 case elfcpp::R_X86_64_GOTOFF64
:
1452 case elfcpp::R_X86_64_GOTPC64
:
1453 case elfcpp::R_X86_64_PLTOFF64
:
1454 // We need a GOT section.
1455 target
->got_section(symtab
, layout
);
1456 // For PLTOFF64, we'd normally want a PLT section, but since we
1457 // know this is a local symbol, no PLT is needed.
1460 case elfcpp::R_X86_64_GOT64
:
1461 case elfcpp::R_X86_64_GOT32
:
1462 case elfcpp::R_X86_64_GOTPCREL64
:
1463 case elfcpp::R_X86_64_GOTPCREL
:
1464 case elfcpp::R_X86_64_GOTPLT64
:
1466 // The symbol requires a GOT entry.
1467 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1468 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1470 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1471 // lets function pointers compare correctly with shared
1472 // libraries. Otherwise we would need an IRELATIVE reloc.
1474 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1475 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1477 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1480 // If we are generating a shared object, we need to add a
1481 // dynamic relocation for this symbol's GOT entry.
1482 if (parameters
->options().output_is_position_independent())
1484 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1485 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1486 if (r_type
!= elfcpp::R_X86_64_GOT32
)
1488 unsigned int got_offset
=
1489 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1490 rela_dyn
->add_local_relative(object
, r_sym
,
1491 elfcpp::R_X86_64_RELATIVE
,
1492 got
, got_offset
, 0);
1496 this->check_non_pic(object
, r_type
);
1498 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1499 rela_dyn
->add_local(
1500 object
, r_sym
, r_type
, got
,
1501 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
1505 // For GOTPLT64, we'd normally want a PLT section, but since
1506 // we know this is a local symbol, no PLT is needed.
1510 case elfcpp::R_X86_64_COPY
:
1511 case elfcpp::R_X86_64_GLOB_DAT
:
1512 case elfcpp::R_X86_64_JUMP_SLOT
:
1513 case elfcpp::R_X86_64_RELATIVE
:
1514 case elfcpp::R_X86_64_IRELATIVE
:
1515 // These are outstanding tls relocs, which are unexpected when linking
1516 case elfcpp::R_X86_64_TPOFF64
:
1517 case elfcpp::R_X86_64_DTPMOD64
:
1518 case elfcpp::R_X86_64_TLSDESC
:
1519 gold_error(_("%s: unexpected reloc %u in object file"),
1520 object
->name().c_str(), r_type
);
1523 // These are initial tls relocs, which are expected when linking
1524 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1525 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1526 case elfcpp::R_X86_64_TLSDESC_CALL
:
1527 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1528 case elfcpp::R_X86_64_DTPOFF32
:
1529 case elfcpp::R_X86_64_DTPOFF64
:
1530 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1531 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1533 bool output_is_shared
= parameters
->options().shared();
1534 const tls::Tls_optimization optimized_type
1535 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
1538 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1539 if (optimized_type
== tls::TLSOPT_NONE
)
1541 // Create a pair of GOT entries for the module index and
1542 // dtv-relative offset.
1543 Output_data_got
<64, false>* got
1544 = target
->got_section(symtab
, layout
);
1545 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1546 unsigned int shndx
= lsym
.get_st_shndx();
1548 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1550 object
->error(_("local symbol %u has bad shndx %u"),
1553 got
->add_local_pair_with_rela(object
, r_sym
,
1556 target
->rela_dyn_section(layout
),
1557 elfcpp::R_X86_64_DTPMOD64
, 0);
1559 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1560 unsupported_reloc_local(object
, r_type
);
1563 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1564 target
->define_tls_base_symbol(symtab
, layout
);
1565 if (optimized_type
== tls::TLSOPT_NONE
)
1567 // Create reserved PLT and GOT entries for the resolver.
1568 target
->reserve_tlsdesc_entries(symtab
, layout
);
1570 // Generate a double GOT entry with an
1571 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
1572 // is resolved lazily, so the GOT entry needs to be in
1573 // an area in .got.plt, not .got. Call got_section to
1574 // make sure the section has been created.
1575 target
->got_section(symtab
, layout
);
1576 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
1577 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1578 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1580 unsigned int got_offset
= got
->add_constant(0);
1581 got
->add_constant(0);
1582 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1584 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
1585 // We store the arguments we need in a vector, and
1586 // use the index into the vector as the parameter
1587 // to pass to the target specific routines.
1588 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
1589 void* arg
= reinterpret_cast<void*>(intarg
);
1590 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
1591 got
, got_offset
, 0);
1594 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1595 unsupported_reloc_local(object
, r_type
);
1598 case elfcpp::R_X86_64_TLSDESC_CALL
:
1601 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1602 if (optimized_type
== tls::TLSOPT_NONE
)
1604 // Create a GOT entry for the module index.
1605 target
->got_mod_index_entry(symtab
, layout
, object
);
1607 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1608 unsupported_reloc_local(object
, r_type
);
1611 case elfcpp::R_X86_64_DTPOFF32
:
1612 case elfcpp::R_X86_64_DTPOFF64
:
1615 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1616 layout
->set_has_static_tls();
1617 if (optimized_type
== tls::TLSOPT_NONE
)
1619 // Create a GOT entry for the tp-relative offset.
1620 Output_data_got
<64, false>* got
1621 = target
->got_section(symtab
, layout
);
1622 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1623 got
->add_local_with_rela(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
1624 target
->rela_dyn_section(layout
),
1625 elfcpp::R_X86_64_TPOFF64
);
1627 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1628 unsupported_reloc_local(object
, r_type
);
1631 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1632 layout
->set_has_static_tls();
1633 if (output_is_shared
)
1634 unsupported_reloc_local(object
, r_type
);
1643 case elfcpp::R_X86_64_SIZE32
:
1644 case elfcpp::R_X86_64_SIZE64
:
1646 gold_error(_("%s: unsupported reloc %u against local symbol"),
1647 object
->name().c_str(), r_type
);
1653 // Report an unsupported relocation against a global symbol.
1656 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
1657 unsigned int r_type
,
1660 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1661 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1664 // Returns true if this relocation type could be that of a function pointer.
1666 Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1670 case elfcpp::R_X86_64_64
:
1671 case elfcpp::R_X86_64_32
:
1672 case elfcpp::R_X86_64_32S
:
1673 case elfcpp::R_X86_64_16
:
1674 case elfcpp::R_X86_64_8
:
1675 case elfcpp::R_X86_64_GOT64
:
1676 case elfcpp::R_X86_64_GOT32
:
1677 case elfcpp::R_X86_64_GOTPCREL64
:
1678 case elfcpp::R_X86_64_GOTPCREL
:
1679 case elfcpp::R_X86_64_GOTPLT64
:
1687 // For safe ICF, scan a relocation for a local symbol to check if it
1688 // corresponds to a function pointer being taken. In that case mark
1689 // the function whose pointer was taken as not foldable.
1692 Target_x86_64::Scan::local_reloc_may_be_function_pointer(
1696 Sized_relobj
<64, false>* ,
1699 const elfcpp::Rela
<64, false>& ,
1700 unsigned int r_type
,
1701 const elfcpp::Sym
<64, false>&)
1703 // When building a shared library, do not fold any local symbols as it is
1704 // not possible to distinguish pointer taken versus a call by looking at
1705 // the relocation types.
1706 return (parameters
->options().shared()
1707 || possible_function_pointer_reloc(r_type
));
1710 // For safe ICF, scan a relocation for a global symbol to check if it
1711 // corresponds to a function pointer being taken. In that case mark
1712 // the function whose pointer was taken as not foldable.
1715 Target_x86_64::Scan::global_reloc_may_be_function_pointer(
1719 Sized_relobj
<64, false>* ,
1722 const elfcpp::Rela
<64, false>& ,
1723 unsigned int r_type
,
1726 // When building a shared library, do not fold symbols whose visibility
1727 // is hidden, internal or protected.
1728 return ((parameters
->options().shared()
1729 && (gsym
->visibility() == elfcpp::STV_INTERNAL
1730 || gsym
->visibility() == elfcpp::STV_PROTECTED
1731 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
1732 || possible_function_pointer_reloc(r_type
));
1735 // Scan a relocation for a global symbol.
1738 Target_x86_64::Scan::global(Symbol_table
* symtab
,
1740 Target_x86_64
* target
,
1741 Sized_relobj
<64, false>* object
,
1742 unsigned int data_shndx
,
1743 Output_section
* output_section
,
1744 const elfcpp::Rela
<64, false>& reloc
,
1745 unsigned int r_type
,
1748 // A STT_GNU_IFUNC symbol may require a PLT entry.
1749 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1750 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1751 target
->make_plt_entry(symtab
, layout
, gsym
);
1755 case elfcpp::R_X86_64_NONE
:
1756 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1757 case elfcpp::R_X86_64_GNU_VTENTRY
:
1760 case elfcpp::R_X86_64_64
:
1761 case elfcpp::R_X86_64_32
:
1762 case elfcpp::R_X86_64_32S
:
1763 case elfcpp::R_X86_64_16
:
1764 case elfcpp::R_X86_64_8
:
1766 // Make a PLT entry if necessary.
1767 if (gsym
->needs_plt_entry())
1769 target
->make_plt_entry(symtab
, layout
, gsym
);
1770 // Since this is not a PC-relative relocation, we may be
1771 // taking the address of a function. In that case we need to
1772 // set the entry in the dynamic symbol table to the address of
1774 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1775 gsym
->set_needs_dynsym_value();
1777 // Make a dynamic relocation if necessary.
1778 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1780 if (gsym
->may_need_copy_reloc())
1782 target
->copy_reloc(symtab
, layout
, object
,
1783 data_shndx
, output_section
, gsym
, reloc
);
1785 else if (r_type
== elfcpp::R_X86_64_64
1786 && gsym
->type() == elfcpp::STT_GNU_IFUNC
1787 && gsym
->can_use_relative_reloc(false)
1788 && !gsym
->is_from_dynobj()
1789 && !gsym
->is_undefined()
1790 && !gsym
->is_preemptible())
1792 // Use an IRELATIVE reloc for a locally defined
1793 // STT_GNU_IFUNC symbol. This makes a function
1794 // address in a PIE executable match the address in a
1795 // shared library that it links against.
1796 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1797 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
1798 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
1799 output_section
, object
,
1801 reloc
.get_r_offset(),
1802 reloc
.get_r_addend());
1804 else if (r_type
== elfcpp::R_X86_64_64
1805 && gsym
->can_use_relative_reloc(false))
1807 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1808 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1809 output_section
, object
,
1811 reloc
.get_r_offset(),
1812 reloc
.get_r_addend());
1816 this->check_non_pic(object
, r_type
);
1817 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1818 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1819 data_shndx
, reloc
.get_r_offset(),
1820 reloc
.get_r_addend());
1826 case elfcpp::R_X86_64_PC64
:
1827 case elfcpp::R_X86_64_PC32
:
1828 case elfcpp::R_X86_64_PC16
:
1829 case elfcpp::R_X86_64_PC8
:
1831 // Make a PLT entry if necessary.
1832 if (gsym
->needs_plt_entry())
1833 target
->make_plt_entry(symtab
, layout
, gsym
);
1834 // Make a dynamic relocation if necessary.
1835 int flags
= Symbol::NON_PIC_REF
;
1836 if (gsym
->is_func())
1837 flags
|= Symbol::FUNCTION_CALL
;
1838 if (gsym
->needs_dynamic_reloc(flags
))
1840 if (gsym
->may_need_copy_reloc())
1842 target
->copy_reloc(symtab
, layout
, object
,
1843 data_shndx
, output_section
, gsym
, reloc
);
1847 this->check_non_pic(object
, r_type
);
1848 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1849 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1850 data_shndx
, reloc
.get_r_offset(),
1851 reloc
.get_r_addend());
1857 case elfcpp::R_X86_64_GOT64
:
1858 case elfcpp::R_X86_64_GOT32
:
1859 case elfcpp::R_X86_64_GOTPCREL64
:
1860 case elfcpp::R_X86_64_GOTPCREL
:
1861 case elfcpp::R_X86_64_GOTPLT64
:
1863 // The symbol requires a GOT entry.
1864 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1865 if (gsym
->final_value_is_known())
1867 // For a STT_GNU_IFUNC symbol we want the PLT address.
1868 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1869 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1871 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1875 // If this symbol is not fully resolved, we need to add a
1876 // dynamic relocation for it.
1877 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1878 if (gsym
->is_from_dynobj()
1879 || gsym
->is_undefined()
1880 || gsym
->is_preemptible()
1881 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
1882 && parameters
->options().output_is_position_independent()))
1883 got
->add_global_with_rela(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
1884 elfcpp::R_X86_64_GLOB_DAT
);
1887 // For a STT_GNU_IFUNC symbol we want to write the PLT
1888 // offset into the GOT, so that function pointer
1889 // comparisons work correctly.
1891 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
1892 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1895 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1896 // Tell the dynamic linker to use the PLT address
1897 // when resolving relocations.
1898 if (gsym
->is_from_dynobj()
1899 && !parameters
->options().shared())
1900 gsym
->set_needs_dynsym_value();
1904 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
1905 rela_dyn
->add_global_relative(gsym
,
1906 elfcpp::R_X86_64_RELATIVE
,
1911 // For GOTPLT64, we also need a PLT entry (but only if the
1912 // symbol is not fully resolved).
1913 if (r_type
== elfcpp::R_X86_64_GOTPLT64
1914 && !gsym
->final_value_is_known())
1915 target
->make_plt_entry(symtab
, layout
, gsym
);
1919 case elfcpp::R_X86_64_PLT32
:
1920 // If the symbol is fully resolved, this is just a PC32 reloc.
1921 // Otherwise we need a PLT entry.
1922 if (gsym
->final_value_is_known())
1924 // If building a shared library, we can also skip the PLT entry
1925 // if the symbol is defined in the output file and is protected
1927 if (gsym
->is_defined()
1928 && !gsym
->is_from_dynobj()
1929 && !gsym
->is_preemptible())
1931 target
->make_plt_entry(symtab
, layout
, gsym
);
1934 case elfcpp::R_X86_64_GOTPC32
:
1935 case elfcpp::R_X86_64_GOTOFF64
:
1936 case elfcpp::R_X86_64_GOTPC64
:
1937 case elfcpp::R_X86_64_PLTOFF64
:
1938 // We need a GOT section.
1939 target
->got_section(symtab
, layout
);
1940 // For PLTOFF64, we also need a PLT entry (but only if the
1941 // symbol is not fully resolved).
1942 if (r_type
== elfcpp::R_X86_64_PLTOFF64
1943 && !gsym
->final_value_is_known())
1944 target
->make_plt_entry(symtab
, layout
, gsym
);
1947 case elfcpp::R_X86_64_COPY
:
1948 case elfcpp::R_X86_64_GLOB_DAT
:
1949 case elfcpp::R_X86_64_JUMP_SLOT
:
1950 case elfcpp::R_X86_64_RELATIVE
:
1951 case elfcpp::R_X86_64_IRELATIVE
:
1952 // These are outstanding tls relocs, which are unexpected when linking
1953 case elfcpp::R_X86_64_TPOFF64
:
1954 case elfcpp::R_X86_64_DTPMOD64
:
1955 case elfcpp::R_X86_64_TLSDESC
:
1956 gold_error(_("%s: unexpected reloc %u in object file"),
1957 object
->name().c_str(), r_type
);
1960 // These are initial tls relocs, which are expected for global()
1961 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1962 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1963 case elfcpp::R_X86_64_TLSDESC_CALL
:
1964 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1965 case elfcpp::R_X86_64_DTPOFF32
:
1966 case elfcpp::R_X86_64_DTPOFF64
:
1967 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1968 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1970 const bool is_final
= gsym
->final_value_is_known();
1971 const tls::Tls_optimization optimized_type
1972 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1975 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1976 if (optimized_type
== tls::TLSOPT_NONE
)
1978 // Create a pair of GOT entries for the module index and
1979 // dtv-relative offset.
1980 Output_data_got
<64, false>* got
1981 = target
->got_section(symtab
, layout
);
1982 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_PAIR
,
1983 target
->rela_dyn_section(layout
),
1984 elfcpp::R_X86_64_DTPMOD64
,
1985 elfcpp::R_X86_64_DTPOFF64
);
1987 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1989 // Create a GOT entry for the tp-relative offset.
1990 Output_data_got
<64, false>* got
1991 = target
->got_section(symtab
, layout
);
1992 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1993 target
->rela_dyn_section(layout
),
1994 elfcpp::R_X86_64_TPOFF64
);
1996 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1997 unsupported_reloc_global(object
, r_type
, gsym
);
2000 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2001 target
->define_tls_base_symbol(symtab
, layout
);
2002 if (optimized_type
== tls::TLSOPT_NONE
)
2004 // Create reserved PLT and GOT entries for the resolver.
2005 target
->reserve_tlsdesc_entries(symtab
, layout
);
2007 // Create a double GOT entry with an R_X86_64_TLSDESC
2008 // reloc. The R_X86_64_TLSDESC reloc is resolved
2009 // lazily, so the GOT entry needs to be in an area in
2010 // .got.plt, not .got. Call got_section to make sure
2011 // the section has been created.
2012 target
->got_section(symtab
, layout
);
2013 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
2014 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
2015 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2016 elfcpp::R_X86_64_TLSDESC
, 0);
2018 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2020 // Create a GOT entry for the tp-relative offset.
2021 Output_data_got
<64, false>* got
2022 = target
->got_section(symtab
, layout
);
2023 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2024 target
->rela_dyn_section(layout
),
2025 elfcpp::R_X86_64_TPOFF64
);
2027 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2028 unsupported_reloc_global(object
, r_type
, gsym
);
2031 case elfcpp::R_X86_64_TLSDESC_CALL
:
2034 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2035 if (optimized_type
== tls::TLSOPT_NONE
)
2037 // Create a GOT entry for the module index.
2038 target
->got_mod_index_entry(symtab
, layout
, object
);
2040 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2041 unsupported_reloc_global(object
, r_type
, gsym
);
2044 case elfcpp::R_X86_64_DTPOFF32
:
2045 case elfcpp::R_X86_64_DTPOFF64
:
2048 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2049 layout
->set_has_static_tls();
2050 if (optimized_type
== tls::TLSOPT_NONE
)
2052 // Create a GOT entry for the tp-relative offset.
2053 Output_data_got
<64, false>* got
2054 = target
->got_section(symtab
, layout
);
2055 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2056 target
->rela_dyn_section(layout
),
2057 elfcpp::R_X86_64_TPOFF64
);
2059 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2060 unsupported_reloc_global(object
, r_type
, gsym
);
2063 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2064 layout
->set_has_static_tls();
2065 if (parameters
->options().shared())
2066 unsupported_reloc_local(object
, r_type
);
2075 case elfcpp::R_X86_64_SIZE32
:
2076 case elfcpp::R_X86_64_SIZE64
:
2078 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2079 object
->name().c_str(), r_type
,
2080 gsym
->demangled_name().c_str());
2086 Target_x86_64::gc_process_relocs(Symbol_table
* symtab
,
2088 Sized_relobj
<64, false>* object
,
2089 unsigned int data_shndx
,
2090 unsigned int sh_type
,
2091 const unsigned char* prelocs
,
2093 Output_section
* output_section
,
2094 bool needs_special_offset_handling
,
2095 size_t local_symbol_count
,
2096 const unsigned char* plocal_symbols
)
2099 if (sh_type
== elfcpp::SHT_REL
)
2104 gold::gc_process_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2105 Target_x86_64::Scan
,
2106 Target_x86_64::Relocatable_size_for_reloc
>(
2115 needs_special_offset_handling
,
2120 // Scan relocations for a section.
2123 Target_x86_64::scan_relocs(Symbol_table
* symtab
,
2125 Sized_relobj
<64, false>* object
,
2126 unsigned int data_shndx
,
2127 unsigned int sh_type
,
2128 const unsigned char* prelocs
,
2130 Output_section
* output_section
,
2131 bool needs_special_offset_handling
,
2132 size_t local_symbol_count
,
2133 const unsigned char* plocal_symbols
)
2135 if (sh_type
== elfcpp::SHT_REL
)
2137 gold_error(_("%s: unsupported REL reloc section"),
2138 object
->name().c_str());
2142 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2143 Target_x86_64::Scan
>(
2152 needs_special_offset_handling
,
2157 // Finalize the sections.
2160 Target_x86_64::do_finalize_sections(
2162 const Input_objects
*,
2163 Symbol_table
* symtab
)
2165 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2167 : this->plt_
->rela_plt());
2168 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
2169 this->rela_dyn_
, true, false);
2171 // Fill in some more dynamic tags.
2172 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
2175 if (this->plt_
!= NULL
2176 && this->plt_
->output_section() != NULL
2177 && this->plt_
->has_tlsdesc_entry())
2179 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
2180 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
2181 this->got_
->finalize_data_size();
2182 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
2183 this->plt_
, plt_offset
);
2184 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
2185 this->got_
, got_offset
);
2189 // Emit any relocs we saved in an attempt to avoid generating COPY
2191 if (this->copy_relocs_
.any_saved_relocs())
2192 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
2194 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2195 // the .got.plt section.
2196 Symbol
* sym
= this->global_offset_table_
;
2199 uint64_t data_size
= this->got_plt_
->current_data_size();
2200 symtab
->get_sized_symbol
<64>(sym
)->set_symsize(data_size
);
2204 // Perform a relocation.
2207 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
2208 Target_x86_64
* target
,
2211 const elfcpp::Rela
<64, false>& rela
,
2212 unsigned int r_type
,
2213 const Sized_symbol
<64>* gsym
,
2214 const Symbol_value
<64>* psymval
,
2215 unsigned char* view
,
2216 elfcpp::Elf_types
<64>::Elf_Addr address
,
2217 section_size_type view_size
)
2219 if (this->skip_call_tls_get_addr_
)
2221 if ((r_type
!= elfcpp::R_X86_64_PLT32
2222 && r_type
!= elfcpp::R_X86_64_PC32
)
2224 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
2226 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2227 _("missing expected TLS relocation"));
2231 this->skip_call_tls_get_addr_
= false;
2236 const Sized_relobj
<64, false>* object
= relinfo
->object
;
2238 // Pick the value to use for symbols defined in the PLT.
2239 Symbol_value
<64> symval
;
2241 && gsym
->use_plt_offset(r_type
== elfcpp::R_X86_64_PC64
2242 || r_type
== elfcpp::R_X86_64_PC32
2243 || r_type
== elfcpp::R_X86_64_PC16
2244 || r_type
== elfcpp::R_X86_64_PC8
))
2246 symval
.set_output_value(target
->plt_section()->address()
2247 + gsym
->plt_offset());
2250 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2252 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2253 if (object
->local_has_plt_offset(r_sym
))
2255 symval
.set_output_value(target
->plt_section()->address()
2256 + object
->local_plt_offset(r_sym
));
2261 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2263 // Get the GOT offset if needed.
2264 // The GOT pointer points to the end of the GOT section.
2265 // We need to subtract the size of the GOT section to get
2266 // the actual offset to use in the relocation.
2267 bool have_got_offset
= false;
2268 unsigned int got_offset
= 0;
2271 case elfcpp::R_X86_64_GOT32
:
2272 case elfcpp::R_X86_64_GOT64
:
2273 case elfcpp::R_X86_64_GOTPLT64
:
2274 case elfcpp::R_X86_64_GOTPCREL
:
2275 case elfcpp::R_X86_64_GOTPCREL64
:
2278 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2279 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
2283 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2284 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2285 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2286 - target
->got_size());
2288 have_got_offset
= true;
2297 case elfcpp::R_X86_64_NONE
:
2298 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2299 case elfcpp::R_X86_64_GNU_VTENTRY
:
2302 case elfcpp::R_X86_64_64
:
2303 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
2306 case elfcpp::R_X86_64_PC64
:
2307 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
2311 case elfcpp::R_X86_64_32
:
2312 // FIXME: we need to verify that value + addend fits into 32 bits:
2313 // uint64_t x = value + addend;
2314 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
2315 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
2316 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
2319 case elfcpp::R_X86_64_32S
:
2320 // FIXME: we need to verify that value + addend fits into 32 bits:
2321 // int64_t x = value + addend; // note this quantity is signed!
2322 // x == static_cast<int64_t>(static_cast<int32_t>(x))
2323 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
2326 case elfcpp::R_X86_64_PC32
:
2327 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2331 case elfcpp::R_X86_64_16
:
2332 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
2335 case elfcpp::R_X86_64_PC16
:
2336 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
2340 case elfcpp::R_X86_64_8
:
2341 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
2344 case elfcpp::R_X86_64_PC8
:
2345 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
2349 case elfcpp::R_X86_64_PLT32
:
2350 gold_assert(gsym
== NULL
2351 || gsym
->has_plt_offset()
2352 || gsym
->final_value_is_known()
2353 || (gsym
->is_defined()
2354 && !gsym
->is_from_dynobj()
2355 && !gsym
->is_preemptible()));
2356 // Note: while this code looks the same as for R_X86_64_PC32, it
2357 // behaves differently because psymval was set to point to
2358 // the PLT entry, rather than the symbol, in Scan::global().
2359 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2363 case elfcpp::R_X86_64_PLTOFF64
:
2366 gold_assert(gsym
->has_plt_offset()
2367 || gsym
->final_value_is_known());
2368 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
2369 got_address
= target
->got_section(NULL
, NULL
)->address();
2370 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
2371 addend
- got_address
);
2374 case elfcpp::R_X86_64_GOT32
:
2375 gold_assert(have_got_offset
);
2376 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
2379 case elfcpp::R_X86_64_GOTPC32
:
2382 elfcpp::Elf_types
<64>::Elf_Addr value
;
2383 value
= target
->got_plt_section()->address();
2384 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2388 case elfcpp::R_X86_64_GOT64
:
2389 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
2390 // Since we always add a PLT entry, this is equivalent.
2391 case elfcpp::R_X86_64_GOTPLT64
:
2392 gold_assert(have_got_offset
);
2393 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
2396 case elfcpp::R_X86_64_GOTPC64
:
2399 elfcpp::Elf_types
<64>::Elf_Addr value
;
2400 value
= target
->got_plt_section()->address();
2401 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
2405 case elfcpp::R_X86_64_GOTOFF64
:
2407 elfcpp::Elf_types
<64>::Elf_Addr value
;
2408 value
= (psymval
->value(object
, 0)
2409 - target
->got_plt_section()->address());
2410 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2414 case elfcpp::R_X86_64_GOTPCREL
:
2416 gold_assert(have_got_offset
);
2417 elfcpp::Elf_types
<64>::Elf_Addr value
;
2418 value
= target
->got_plt_section()->address() + got_offset
;
2419 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2423 case elfcpp::R_X86_64_GOTPCREL64
:
2425 gold_assert(have_got_offset
);
2426 elfcpp::Elf_types
<64>::Elf_Addr value
;
2427 value
= target
->got_plt_section()->address() + got_offset
;
2428 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
2432 case elfcpp::R_X86_64_COPY
:
2433 case elfcpp::R_X86_64_GLOB_DAT
:
2434 case elfcpp::R_X86_64_JUMP_SLOT
:
2435 case elfcpp::R_X86_64_RELATIVE
:
2436 case elfcpp::R_X86_64_IRELATIVE
:
2437 // These are outstanding tls relocs, which are unexpected when linking
2438 case elfcpp::R_X86_64_TPOFF64
:
2439 case elfcpp::R_X86_64_DTPMOD64
:
2440 case elfcpp::R_X86_64_TLSDESC
:
2441 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2442 _("unexpected reloc %u in object file"),
2446 // These are initial tls relocs, which are expected when linking
2447 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2448 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2449 case elfcpp::R_X86_64_TLSDESC_CALL
:
2450 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2451 case elfcpp::R_X86_64_DTPOFF32
:
2452 case elfcpp::R_X86_64_DTPOFF64
:
2453 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2454 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2455 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
2456 view
, address
, view_size
);
2459 case elfcpp::R_X86_64_SIZE32
:
2460 case elfcpp::R_X86_64_SIZE64
:
2462 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2463 _("unsupported reloc %u"),
2471 // Perform a TLS relocation.
2474 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
2475 Target_x86_64
* target
,
2477 const elfcpp::Rela
<64, false>& rela
,
2478 unsigned int r_type
,
2479 const Sized_symbol
<64>* gsym
,
2480 const Symbol_value
<64>* psymval
,
2481 unsigned char* view
,
2482 elfcpp::Elf_types
<64>::Elf_Addr address
,
2483 section_size_type view_size
)
2485 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2487 const Sized_relobj
<64, false>* object
= relinfo
->object
;
2488 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2489 elfcpp::Shdr
<64, false> data_shdr(relinfo
->data_shdr
);
2490 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
2492 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
2494 const bool is_final
= (gsym
== NULL
2495 ? !parameters
->options().shared()
2496 : gsym
->final_value_is_known());
2497 tls::Tls_optimization optimized_type
2498 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
2501 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2502 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
2504 // If this code sequence is used in a non-executable section,
2505 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
2506 // on the assumption that it's being used by itself in a debug
2507 // section. Therefore, in the unlikely event that the code
2508 // sequence appears in a non-executable section, we simply
2509 // leave it unoptimized.
2510 optimized_type
= tls::TLSOPT_NONE
;
2512 if (optimized_type
== tls::TLSOPT_TO_LE
)
2514 gold_assert(tls_segment
!= NULL
);
2515 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2516 rela
, r_type
, value
, view
,
2522 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2523 ? GOT_TYPE_TLS_OFFSET
2524 : GOT_TYPE_TLS_PAIR
);
2525 unsigned int got_offset
;
2528 gold_assert(gsym
->has_got_offset(got_type
));
2529 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2533 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2534 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2535 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2536 - target
->got_size());
2538 if (optimized_type
== tls::TLSOPT_TO_IE
)
2540 gold_assert(tls_segment
!= NULL
);
2541 value
= target
->got_plt_section()->address() + got_offset
;
2542 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2543 value
, view
, address
, view_size
);
2546 else if (optimized_type
== tls::TLSOPT_NONE
)
2548 // Relocate the field with the offset of the pair of GOT
2550 value
= target
->got_plt_section()->address() + got_offset
;
2551 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2556 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2557 _("unsupported reloc %u"), r_type
);
2560 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2561 case elfcpp::R_X86_64_TLSDESC_CALL
:
2562 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
2564 // See above comment for R_X86_64_TLSGD.
2565 optimized_type
= tls::TLSOPT_NONE
;
2567 if (optimized_type
== tls::TLSOPT_TO_LE
)
2569 gold_assert(tls_segment
!= NULL
);
2570 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2571 rela
, r_type
, value
, view
,
2577 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2578 ? GOT_TYPE_TLS_OFFSET
2579 : GOT_TYPE_TLS_DESC
);
2580 unsigned int got_offset
= 0;
2581 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
2582 && optimized_type
== tls::TLSOPT_NONE
)
2584 // We created GOT entries in the .got.tlsdesc portion of
2585 // the .got.plt section, but the offset stored in the
2586 // symbol is the offset within .got.tlsdesc.
2587 got_offset
= (target
->got_size()
2588 + target
->got_plt_section()->data_size());
2592 gold_assert(gsym
->has_got_offset(got_type
));
2593 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2597 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2598 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2599 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2600 - target
->got_size());
2602 if (optimized_type
== tls::TLSOPT_TO_IE
)
2604 gold_assert(tls_segment
!= NULL
);
2605 value
= target
->got_plt_section()->address() + got_offset
;
2606 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
,
2607 rela
, r_type
, value
, view
, address
,
2611 else if (optimized_type
== tls::TLSOPT_NONE
)
2613 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2615 // Relocate the field with the offset of the pair of GOT
2617 value
= target
->got_plt_section()->address() + got_offset
;
2618 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2624 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2625 _("unsupported reloc %u"), r_type
);
2628 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2629 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
2631 // See above comment for R_X86_64_TLSGD.
2632 optimized_type
= tls::TLSOPT_NONE
;
2634 if (optimized_type
== tls::TLSOPT_TO_LE
)
2636 gold_assert(tls_segment
!= NULL
);
2637 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2638 value
, view
, view_size
);
2641 else if (optimized_type
== tls::TLSOPT_NONE
)
2643 // Relocate the field with the offset of the GOT entry for
2644 // the module index.
2645 unsigned int got_offset
;
2646 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2647 - target
->got_size());
2648 value
= target
->got_plt_section()->address() + got_offset
;
2649 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2653 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2654 _("unsupported reloc %u"), r_type
);
2657 case elfcpp::R_X86_64_DTPOFF32
:
2658 // This relocation type is used in debugging information.
2659 // In that case we need to not optimize the value. If the
2660 // section is not executable, then we assume we should not
2661 // optimize this reloc. See comments above for R_X86_64_TLSGD,
2662 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
2664 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
2666 gold_assert(tls_segment
!= NULL
);
2667 value
-= tls_segment
->memsz();
2669 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2672 case elfcpp::R_X86_64_DTPOFF64
:
2673 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
2674 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
2676 gold_assert(tls_segment
!= NULL
);
2677 value
-= tls_segment
->memsz();
2679 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2682 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2683 if (optimized_type
== tls::TLSOPT_TO_LE
)
2685 gold_assert(tls_segment
!= NULL
);
2686 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2687 rela
, r_type
, value
, view
,
2691 else if (optimized_type
== tls::TLSOPT_NONE
)
2693 // Relocate the field with the offset of the GOT entry for
2694 // the tp-relative offset of the symbol.
2695 unsigned int got_offset
;
2698 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
2699 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
2700 - target
->got_size());
2704 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2705 gold_assert(object
->local_has_got_offset(r_sym
,
2706 GOT_TYPE_TLS_OFFSET
));
2707 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
2708 - target
->got_size());
2710 value
= target
->got_plt_section()->address() + got_offset
;
2711 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2714 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2715 _("unsupported reloc type %u"),
2719 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2720 value
-= tls_segment
->memsz();
2721 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2726 // Do a relocation in which we convert a TLS General-Dynamic to an
2730 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info
<64, false>* relinfo
,
2733 const elfcpp::Rela
<64, false>& rela
,
2735 elfcpp::Elf_types
<64>::Elf_Addr value
,
2736 unsigned char* view
,
2737 elfcpp::Elf_types
<64>::Elf_Addr address
,
2738 section_size_type view_size
)
2740 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2741 // .word 0x6666; rex64; call __tls_get_addr
2742 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2744 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2745 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2747 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2748 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2749 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2750 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2752 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2754 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2755 Relocate_functions
<64, false>::pcrela32(view
+ 8, value
, addend
- 8, address
);
2757 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2759 this->skip_call_tls_get_addr_
= true;
2762 // Do a relocation in which we convert a TLS General-Dynamic to a
2766 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
2768 Output_segment
* tls_segment
,
2769 const elfcpp::Rela
<64, false>& rela
,
2771 elfcpp::Elf_types
<64>::Elf_Addr value
,
2772 unsigned char* view
,
2773 section_size_type view_size
)
2775 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2776 // .word 0x6666; rex64; call __tls_get_addr
2777 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2779 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2780 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2782 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2783 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2784 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2785 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2787 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2789 value
-= tls_segment
->memsz();
2790 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
2792 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2794 this->skip_call_tls_get_addr_
= true;
2797 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2800 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2801 const Relocate_info
<64, false>* relinfo
,
2804 const elfcpp::Rela
<64, false>& rela
,
2805 unsigned int r_type
,
2806 elfcpp::Elf_types
<64>::Elf_Addr value
,
2807 unsigned char* view
,
2808 elfcpp::Elf_types
<64>::Elf_Addr address
,
2809 section_size_type view_size
)
2811 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2813 // leaq foo@tlsdesc(%rip), %rax
2814 // ==> movq foo@gottpoff(%rip), %rax
2815 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2816 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2817 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2818 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2820 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2821 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2825 // call *foo@tlscall(%rax)
2827 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2828 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2829 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2830 view
[0] == 0xff && view
[1] == 0x10);
2836 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2839 Target_x86_64::Relocate::tls_desc_gd_to_le(
2840 const Relocate_info
<64, false>* relinfo
,
2842 Output_segment
* tls_segment
,
2843 const elfcpp::Rela
<64, false>& rela
,
2844 unsigned int r_type
,
2845 elfcpp::Elf_types
<64>::Elf_Addr value
,
2846 unsigned char* view
,
2847 section_size_type view_size
)
2849 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2851 // leaq foo@tlsdesc(%rip), %rax
2852 // ==> movq foo@tpoff, %rax
2853 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2854 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2855 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2856 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2859 value
-= tls_segment
->memsz();
2860 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2864 // call *foo@tlscall(%rax)
2866 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2867 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2868 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2869 view
[0] == 0xff && view
[1] == 0x10);
2876 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
2879 const elfcpp::Rela
<64, false>& rela
,
2881 elfcpp::Elf_types
<64>::Elf_Addr
,
2882 unsigned char* view
,
2883 section_size_type view_size
)
2885 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2886 // ... leq foo@dtpoff(%rax),%reg
2887 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2889 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2890 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
2892 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2893 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
2895 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
2897 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2899 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2901 this->skip_call_tls_get_addr_
= true;
2904 // Do a relocation in which we convert a TLS Initial-Exec to a
2908 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
2910 Output_segment
* tls_segment
,
2911 const elfcpp::Rela
<64, false>& rela
,
2913 elfcpp::Elf_types
<64>::Elf_Addr value
,
2914 unsigned char* view
,
2915 section_size_type view_size
)
2917 // We need to examine the opcodes to figure out which instruction we
2920 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
2921 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
2923 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2924 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2926 unsigned char op1
= view
[-3];
2927 unsigned char op2
= view
[-2];
2928 unsigned char op3
= view
[-1];
2929 unsigned char reg
= op3
>> 3;
2937 view
[-1] = 0xc0 | reg
;
2941 // Special handling for %rsp.
2945 view
[-1] = 0xc0 | reg
;
2953 view
[-1] = 0x80 | reg
| (reg
<< 3);
2956 value
-= tls_segment
->memsz();
2957 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2960 // Relocate section data.
2963 Target_x86_64::relocate_section(
2964 const Relocate_info
<64, false>* relinfo
,
2965 unsigned int sh_type
,
2966 const unsigned char* prelocs
,
2968 Output_section
* output_section
,
2969 bool needs_special_offset_handling
,
2970 unsigned char* view
,
2971 elfcpp::Elf_types
<64>::Elf_Addr address
,
2972 section_size_type view_size
,
2973 const Reloc_symbol_changes
* reloc_symbol_changes
)
2975 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2977 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2978 Target_x86_64::Relocate
>(
2984 needs_special_offset_handling
,
2988 reloc_symbol_changes
);
2991 // Return the size of a relocation while scanning during a relocatable
2995 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2996 unsigned int r_type
,
3001 case elfcpp::R_X86_64_NONE
:
3002 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3003 case elfcpp::R_X86_64_GNU_VTENTRY
:
3004 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3005 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3006 case elfcpp::R_X86_64_TLSDESC_CALL
:
3007 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3008 case elfcpp::R_X86_64_DTPOFF32
:
3009 case elfcpp::R_X86_64_DTPOFF64
:
3010 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3011 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3014 case elfcpp::R_X86_64_64
:
3015 case elfcpp::R_X86_64_PC64
:
3016 case elfcpp::R_X86_64_GOTOFF64
:
3017 case elfcpp::R_X86_64_GOTPC64
:
3018 case elfcpp::R_X86_64_PLTOFF64
:
3019 case elfcpp::R_X86_64_GOT64
:
3020 case elfcpp::R_X86_64_GOTPCREL64
:
3021 case elfcpp::R_X86_64_GOTPCREL
:
3022 case elfcpp::R_X86_64_GOTPLT64
:
3025 case elfcpp::R_X86_64_32
:
3026 case elfcpp::R_X86_64_32S
:
3027 case elfcpp::R_X86_64_PC32
:
3028 case elfcpp::R_X86_64_PLT32
:
3029 case elfcpp::R_X86_64_GOTPC32
:
3030 case elfcpp::R_X86_64_GOT32
:
3033 case elfcpp::R_X86_64_16
:
3034 case elfcpp::R_X86_64_PC16
:
3037 case elfcpp::R_X86_64_8
:
3038 case elfcpp::R_X86_64_PC8
:
3041 case elfcpp::R_X86_64_COPY
:
3042 case elfcpp::R_X86_64_GLOB_DAT
:
3043 case elfcpp::R_X86_64_JUMP_SLOT
:
3044 case elfcpp::R_X86_64_RELATIVE
:
3045 case elfcpp::R_X86_64_IRELATIVE
:
3046 // These are outstanding tls relocs, which are unexpected when linking
3047 case elfcpp::R_X86_64_TPOFF64
:
3048 case elfcpp::R_X86_64_DTPMOD64
:
3049 case elfcpp::R_X86_64_TLSDESC
:
3050 object
->error(_("unexpected reloc %u in object file"), r_type
);
3053 case elfcpp::R_X86_64_SIZE32
:
3054 case elfcpp::R_X86_64_SIZE64
:
3056 object
->error(_("unsupported reloc %u against local symbol"), r_type
);
3061 // Scan the relocs during a relocatable link.
3064 Target_x86_64::scan_relocatable_relocs(Symbol_table
* symtab
,
3066 Sized_relobj
<64, false>* object
,
3067 unsigned int data_shndx
,
3068 unsigned int sh_type
,
3069 const unsigned char* prelocs
,
3071 Output_section
* output_section
,
3072 bool needs_special_offset_handling
,
3073 size_t local_symbol_count
,
3074 const unsigned char* plocal_symbols
,
3075 Relocatable_relocs
* rr
)
3077 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3079 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_RELA
,
3080 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3082 gold::scan_relocatable_relocs
<64, false, elfcpp::SHT_RELA
,
3083 Scan_relocatable_relocs
>(
3091 needs_special_offset_handling
,
3097 // Relocate a section during a relocatable link.
3100 Target_x86_64::relocate_for_relocatable(
3101 const Relocate_info
<64, false>* relinfo
,
3102 unsigned int sh_type
,
3103 const unsigned char* prelocs
,
3105 Output_section
* output_section
,
3106 off_t offset_in_output_section
,
3107 const Relocatable_relocs
* rr
,
3108 unsigned char* view
,
3109 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
3110 section_size_type view_size
,
3111 unsigned char* reloc_view
,
3112 section_size_type reloc_view_size
)
3114 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3116 gold::relocate_for_relocatable
<64, false, elfcpp::SHT_RELA
>(
3121 offset_in_output_section
,
3130 // Return the value to use for a dynamic which requires special
3131 // treatment. This is how we support equality comparisons of function
3132 // pointers across shared library boundaries, as described in the
3133 // processor specific ABI supplement.
3136 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
3138 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3139 return this->plt_section()->address() + gsym
->plt_offset();
3142 // Return a string used to fill a code section with nops to take up
3143 // the specified length.
3146 Target_x86_64::do_code_fill(section_size_type length
) const
3150 // Build a jmpq instruction to skip over the bytes.
3151 unsigned char jmp
[5];
3153 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3154 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3155 + std::string(length
- 5, '\0'));
3158 // Nop sequences of various lengths.
3159 const char nop1
[1] = { 0x90 }; // nop
3160 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
3161 const char nop3
[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
3162 const char nop4
[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
3163 const char nop5
[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
3165 const char nop6
[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
3167 const char nop7
[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
3169 const char nop8
[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
3170 0x00, 0x00, 0x00, 0x00 };
3171 const char nop9
[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
3172 0x00, 0x00, 0x00, 0x00,
3174 const char nop10
[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
3175 0x84, 0x00, 0x00, 0x00,
3177 const char nop11
[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
3178 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3180 const char nop12
[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
3181 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
3182 0x00, 0x00, 0x00, 0x00 };
3183 const char nop13
[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3184 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
3185 0x00, 0x00, 0x00, 0x00,
3187 const char nop14
[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3188 0x66, 0x2e, 0x0f, 0x1f, // data16
3189 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3191 const char nop15
[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3192 0x66, 0x66, 0x2e, 0x0f, // data16; data16
3193 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3196 const char* nops
[16] = {
3198 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3199 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3202 return std::string(nops
[length
], length
);
3205 // Return the addend to use for a target specific relocation. The
3206 // only target specific relocation is R_X86_64_TLSDESC for a local
3207 // symbol. We want to set the addend is the offset of the local
3208 // symbol in the TLS segment.
3211 Target_x86_64::do_reloc_addend(void* arg
, unsigned int r_type
,
3214 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
3215 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
3216 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
3217 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
3218 const Symbol_value
<64>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
3219 gold_assert(psymval
->is_tls_symbol());
3220 // The value of a TLS symbol is the offset in the TLS segment.
3221 return psymval
->value(ti
.object
, 0);
3224 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3225 // compiled with -fstack-split. The function calls non-stack-split
3226 // code. We have to change the function so that it always ensures
3227 // that it has enough stack space to run some random function.
3230 Target_x86_64::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3231 section_offset_type fnoffset
,
3232 section_size_type fnsize
,
3233 unsigned char* view
,
3234 section_size_type view_size
,
3236 std::string
* to
) const
3238 // The function starts with a comparison of the stack pointer and a
3239 // field in the TCB. This is followed by a jump.
3242 if (this->match_view(view
, view_size
, fnoffset
, "\x64\x48\x3b\x24\x25", 5)
3245 // We will call __morestack if the carry flag is set after this
3246 // comparison. We turn the comparison into an stc instruction
3248 view
[fnoffset
] = '\xf9';
3249 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 8);
3251 // lea NN(%rsp),%r10
3252 // lea NN(%rsp),%r11
3253 else if ((this->match_view(view
, view_size
, fnoffset
,
3254 "\x4c\x8d\x94\x24", 4)
3255 || this->match_view(view
, view_size
, fnoffset
,
3256 "\x4c\x8d\x9c\x24", 4))
3259 // This is loading an offset from the stack pointer for a
3260 // comparison. The offset is negative, so we decrease the
3261 // offset by the amount of space we need for the stack. This
3262 // means we will avoid calling __morestack if there happens to
3263 // be plenty of space on the stack already.
3264 unsigned char* pval
= view
+ fnoffset
+ 4;
3265 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3266 val
-= parameters
->options().split_stack_adjust_size();
3267 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3271 if (!object
->has_no_split_stack())
3272 object
->error(_("failed to match split-stack sequence at "
3273 "section %u offset %0zx"),
3274 shndx
, static_cast<size_t>(fnoffset
));
3278 // We have to change the function so that it calls
3279 // __morestack_non_split instead of __morestack. The former will
3280 // allocate additional stack space.
3281 *from
= "__morestack";
3282 *to
= "__morestack_non_split";
3285 // The selector for x86_64 object files.
3287 class Target_selector_x86_64
: public Target_selector_freebsd
3290 Target_selector_x86_64()
3291 : Target_selector_freebsd(elfcpp::EM_X86_64
, 64, false, "elf64-x86-64",
3292 "elf64-x86-64-freebsd")
3296 do_instantiate_target()
3297 { return new Target_x86_64(); }
3301 Target_selector_x86_64 target_selector_x86_64
;
3303 } // End anonymous namespace.