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), saw_tls_block_reloc_(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_
;
515 // This is set if we see a relocation which could load the address
516 // of the TLS block. Whether we see such a relocation determines
517 // how we handle the R_X86_64_DTPOFF32 relocation, which is used
518 // in debugging sections.
519 bool saw_tls_block_reloc_
;
522 // A class which returns the size required for a relocation type,
523 // used while scanning relocs during a relocatable link.
524 class Relocatable_size_for_reloc
528 get_size_for_reloc(unsigned int, Relobj
*);
531 // Adjust TLS relocation type based on the options and whether this
532 // is a local symbol.
533 static tls::Tls_optimization
534 optimize_tls_reloc(bool is_final
, int r_type
);
536 // Get the GOT section, creating it if necessary.
537 Output_data_got
<64, false>*
538 got_section(Symbol_table
*, Layout
*);
540 // Get the GOT PLT section.
542 got_plt_section() const
544 gold_assert(this->got_plt_
!= NULL
);
545 return this->got_plt_
;
548 // Get the GOT section for TLSDESC entries.
549 Output_data_got
<64, false>*
550 got_tlsdesc_section() const
552 gold_assert(this->got_tlsdesc_
!= NULL
);
553 return this->got_tlsdesc_
;
556 // Create the PLT section.
558 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
560 // Create a PLT entry for a global symbol.
562 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
564 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
566 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
567 Sized_relobj
<64, false>* relobj
,
568 unsigned int local_sym_index
);
570 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
572 define_tls_base_symbol(Symbol_table
*, Layout
*);
574 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
576 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
578 // Create a GOT entry for the TLS module index.
580 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
581 Sized_relobj
<64, false>* object
);
583 // Get the PLT section.
584 Output_data_plt_x86_64
*
587 gold_assert(this->plt_
!= NULL
);
591 // Get the dynamic reloc section, creating it if necessary.
593 rela_dyn_section(Layout
*);
595 // Get the section to use for TLSDESC relocations.
597 rela_tlsdesc_section(Layout
*) const;
599 // Add a potential copy relocation.
601 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
602 Sized_relobj
<64, false>* object
,
603 unsigned int shndx
, Output_section
* output_section
,
604 Symbol
* sym
, const elfcpp::Rela
<64, false>& reloc
)
606 this->copy_relocs_
.copy_reloc(symtab
, layout
,
607 symtab
->get_sized_symbol
<64>(sym
),
608 object
, shndx
, output_section
,
609 reloc
, this->rela_dyn_section(layout
));
612 // Information about this specific target which we pass to the
613 // general Target structure.
614 static const Target::Target_info x86_64_info
;
616 // The types of GOT entries needed for this platform.
617 // These values are exposed to the ABI in an incremental link.
618 // Do not renumber existing values without changing the version
619 // number of the .gnu_incremental_inputs section.
622 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
623 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
624 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
625 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
628 // This type is used as the argument to the target specific
629 // relocation routines. The only target specific reloc is
630 // R_X86_64_TLSDESC against a local symbol.
633 Tlsdesc_info(Sized_relobj
<64, false>* a_object
, unsigned int a_r_sym
)
634 : object(a_object
), r_sym(a_r_sym
)
637 // The object in which the local symbol is defined.
638 Sized_relobj
<64, false>* object
;
639 // The local symbol index in the object.
644 Output_data_got
<64, false>* got_
;
646 Output_data_plt_x86_64
* plt_
;
647 // The GOT PLT section.
648 Output_data_space
* got_plt_
;
649 // The GOT section for TLSDESC relocations.
650 Output_data_got
<64, false>* got_tlsdesc_
;
651 // The _GLOBAL_OFFSET_TABLE_ symbol.
652 Symbol
* global_offset_table_
;
653 // The dynamic reloc section.
654 Reloc_section
* rela_dyn_
;
655 // Relocs saved to avoid a COPY reloc.
656 Copy_relocs
<elfcpp::SHT_RELA
, 64, false> copy_relocs_
;
657 // Space for variables copied with a COPY reloc.
658 Output_data_space
* dynbss_
;
659 // Offset of the GOT entry for the TLS module index.
660 unsigned int got_mod_index_offset_
;
661 // We handle R_X86_64_TLSDESC against a local symbol as a target
662 // specific relocation. Here we store the object and local symbol
663 // index for the relocation.
664 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
665 // True if the _TLS_MODULE_BASE_ symbol has been defined.
666 bool tls_base_symbol_defined_
;
669 const Target::Target_info
Target_x86_64::x86_64_info
=
672 false, // is_big_endian
673 elfcpp::EM_X86_64
, // machine_code
674 false, // has_make_symbol
675 false, // has_resolve
676 true, // has_code_fill
677 true, // is_default_stack_executable
679 "/lib/ld64.so.1", // program interpreter
680 0x400000, // default_text_segment_address
681 0x1000, // abi_pagesize (overridable by -z max-page-size)
682 0x1000, // common_pagesize (overridable by -z common-page-size)
683 elfcpp::SHN_UNDEF
, // small_common_shndx
684 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
685 0, // small_common_section_flags
686 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
687 NULL
, // attributes_section
688 NULL
// attributes_vendor
691 // This is called when a new output section is created. This is where
692 // we handle the SHF_X86_64_LARGE.
695 Target_x86_64::do_new_output_section(Output_section
*os
) const
697 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
698 os
->set_is_large_section();
701 // Get the GOT section, creating it if necessary.
703 Output_data_got
<64, false>*
704 Target_x86_64::got_section(Symbol_table
* symtab
, Layout
* layout
)
706 if (this->got_
== NULL
)
708 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
710 this->got_
= new Output_data_got
<64, false>();
712 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
714 | elfcpp::SHF_WRITE
),
715 this->got_
, ORDER_RELRO_LAST
,
718 this->got_plt_
= new Output_data_space(8, "** GOT PLT");
719 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
721 | elfcpp::SHF_WRITE
),
722 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
725 // The first three entries are reserved.
726 this->got_plt_
->set_current_data_size(3 * 8);
728 // Those bytes can go into the relro segment.
729 layout
->increase_relro(3 * 8);
731 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
732 this->global_offset_table_
=
733 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
734 Symbol_table::PREDEFINED
,
736 0, 0, elfcpp::STT_OBJECT
,
738 elfcpp::STV_HIDDEN
, 0,
741 // If there are any TLSDESC relocations, they get GOT entries in
742 // .got.plt after the jump slot entries.
743 this->got_tlsdesc_
= new Output_data_got
<64, false>();
744 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
746 | elfcpp::SHF_WRITE
),
748 ORDER_NON_RELRO_FIRST
, false);
754 // Get the dynamic reloc section, creating it if necessary.
756 Target_x86_64::Reloc_section
*
757 Target_x86_64::rela_dyn_section(Layout
* layout
)
759 if (this->rela_dyn_
== NULL
)
761 gold_assert(layout
!= NULL
);
762 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
763 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
764 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
765 ORDER_DYNAMIC_RELOCS
, false);
767 return this->rela_dyn_
;
770 // Create the PLT section. The ordinary .got section is an argument,
771 // since we need to refer to the start. We also create our own .got
772 // section just for PLT entries.
774 Output_data_plt_x86_64::Output_data_plt_x86_64(Symbol_table
* symtab
,
776 Output_data_got
<64, false>* got
,
777 Output_data_space
* got_plt
)
778 : Output_section_data(8), tlsdesc_rel_(NULL
), got_(got
), got_plt_(got_plt
),
779 count_(0), tlsdesc_got_offset_(-1U)
781 this->rel_
= new Reloc_section(false);
782 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
783 elfcpp::SHF_ALLOC
, this->rel_
,
784 ORDER_DYNAMIC_PLT_RELOCS
, false);
786 if (parameters
->doing_static_link())
788 // A statically linked executable will only have a .rela.plt
789 // section to hold R_X86_64_IRELATIVE relocs for STT_GNU_IFUNC
790 // symbols. The library will use these symbols to locate the
791 // IRELATIVE relocs at program startup time.
792 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
793 Symbol_table::PREDEFINED
,
794 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
795 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
797 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
798 Symbol_table::PREDEFINED
,
799 this->rel_
, 0, 0, elfcpp::STT_NOTYPE
,
800 elfcpp::STB_GLOBAL
, elfcpp::STV_HIDDEN
,
806 Output_data_plt_x86_64::do_adjust_output_section(Output_section
* os
)
808 os
->set_entsize(plt_entry_size
);
811 // Add an entry to the PLT.
814 Output_data_plt_x86_64::add_entry(Symbol
* gsym
)
816 gold_assert(!gsym
->has_plt_offset());
818 // Note that when setting the PLT offset we skip the initial
819 // reserved PLT entry.
820 gsym
->set_plt_offset((this->count_
+ 1) * plt_entry_size
);
824 section_offset_type got_offset
= this->got_plt_
->current_data_size();
826 // Every PLT entry needs a GOT entry which points back to the PLT
827 // entry (this will be changed by the dynamic linker, normally
828 // lazily when the function is called).
829 this->got_plt_
->set_current_data_size(got_offset
+ 8);
831 // Every PLT entry needs a reloc.
832 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
833 && gsym
->can_use_relative_reloc(false))
834 this->rel_
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
835 this->got_plt_
, got_offset
, 0);
838 gsym
->set_needs_dynsym_entry();
839 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
843 // Note that we don't need to save the symbol. The contents of the
844 // PLT are independent of which symbols are used. The symbols only
845 // appear in the relocations.
848 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
852 Output_data_plt_x86_64::add_local_ifunc_entry(Sized_relobj
<64, false>* relobj
,
853 unsigned int local_sym_index
)
855 unsigned int plt_offset
= (this->count_
+ 1) * plt_entry_size
;
858 section_offset_type got_offset
= this->got_plt_
->current_data_size();
860 // Every PLT entry needs a GOT entry which points back to the PLT
862 this->got_plt_
->set_current_data_size(got_offset
+ 8);
864 // Every PLT entry needs a reloc.
865 this->rel_
->add_symbolless_local_addend(relobj
, local_sym_index
,
866 elfcpp::R_X86_64_IRELATIVE
,
867 this->got_plt_
, got_offset
, 0);
872 // Return where the TLSDESC relocations should go, creating it if
873 // necessary. These follow the JUMP_SLOT relocations.
875 Output_data_plt_x86_64::Reloc_section
*
876 Output_data_plt_x86_64::rela_tlsdesc(Layout
* layout
)
878 if (this->tlsdesc_rel_
== NULL
)
880 this->tlsdesc_rel_
= new Reloc_section(false);
881 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
882 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
883 ORDER_DYNAMIC_PLT_RELOCS
, false);
884 gold_assert(this->tlsdesc_rel_
->output_section() ==
885 this->rel_
->output_section());
887 return this->tlsdesc_rel_
;
890 // Set the final size.
892 Output_data_plt_x86_64::set_final_data_size()
894 unsigned int count
= this->count_
;
895 if (this->has_tlsdesc_entry())
897 this->set_data_size((count
+ 1) * plt_entry_size
);
900 // The first entry in the PLT for an executable.
902 unsigned char Output_data_plt_x86_64::first_plt_entry
[plt_entry_size
] =
904 // From AMD64 ABI Draft 0.98, page 76
905 0xff, 0x35, // pushq contents of memory address
906 0, 0, 0, 0, // replaced with address of .got + 8
907 0xff, 0x25, // jmp indirect
908 0, 0, 0, 0, // replaced with address of .got + 16
909 0x90, 0x90, 0x90, 0x90 // noop (x4)
912 // Subsequent entries in the PLT for an executable.
914 unsigned char Output_data_plt_x86_64::plt_entry
[plt_entry_size
] =
916 // From AMD64 ABI Draft 0.98, page 76
917 0xff, 0x25, // jmpq indirect
918 0, 0, 0, 0, // replaced with address of symbol in .got
919 0x68, // pushq immediate
920 0, 0, 0, 0, // replaced with offset into relocation table
921 0xe9, // jmpq relative
922 0, 0, 0, 0 // replaced with offset to start of .plt
925 // The reserved TLSDESC entry in the PLT for an executable.
927 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry
[plt_entry_size
] =
929 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
930 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
931 0xff, 0x35, // pushq x(%rip)
932 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
933 0xff, 0x25, // jmpq *y(%rip)
934 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
939 // Write out the PLT. This uses the hand-coded instructions above,
940 // and adjusts them as needed. This is specified by the AMD64 ABI.
943 Output_data_plt_x86_64::do_write(Output_file
* of
)
945 const off_t offset
= this->offset();
946 const section_size_type oview_size
=
947 convert_to_section_size_type(this->data_size());
948 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
950 const off_t got_file_offset
= this->got_plt_
->offset();
951 const section_size_type got_size
=
952 convert_to_section_size_type(this->got_plt_
->data_size());
953 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
956 unsigned char* pov
= oview
;
958 // The base address of the .plt section.
959 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
960 // The base address of the .got section.
961 elfcpp::Elf_types
<64>::Elf_Addr got_base
= this->got_
->address();
962 // The base address of the PLT portion of the .got section,
963 // which is where the GOT pointer will point, and where the
964 // three reserved GOT entries are located.
965 elfcpp::Elf_types
<64>::Elf_Addr got_address
= this->got_plt_
->address();
967 memcpy(pov
, first_plt_entry
, plt_entry_size
);
968 // We do a jmp relative to the PC at the end of this instruction.
969 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
971 - (plt_address
+ 6)));
972 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
974 - (plt_address
+ 12)));
975 pov
+= plt_entry_size
;
977 unsigned char* got_pov
= got_view
;
979 memset(got_pov
, 0, 24);
982 unsigned int plt_offset
= plt_entry_size
;
983 unsigned int got_offset
= 24;
984 const unsigned int count
= this->count_
;
985 for (unsigned int plt_index
= 0;
988 pov
+= plt_entry_size
,
990 plt_offset
+= plt_entry_size
,
993 // Set and adjust the PLT entry itself.
994 memcpy(pov
, plt_entry
, plt_entry_size
);
995 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
996 (got_address
+ got_offset
997 - (plt_address
+ plt_offset
1000 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
1001 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
1002 - (plt_offset
+ plt_entry_size
));
1004 // Set the entry in the GOT.
1005 elfcpp::Swap
<64, false>::writeval(got_pov
, plt_address
+ plt_offset
+ 6);
1008 if (this->has_tlsdesc_entry())
1010 // Set and adjust the reserved TLSDESC PLT entry.
1011 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
1012 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1013 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1015 - (plt_address
+ plt_offset
1017 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
1019 + tlsdesc_got_offset
1020 - (plt_address
+ plt_offset
1022 pov
+= plt_entry_size
;
1025 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1026 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1028 of
->write_output_view(offset
, oview_size
, oview
);
1029 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1032 // Create the PLT section.
1035 Target_x86_64::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1037 if (this->plt_
== NULL
)
1039 // Create the GOT sections first.
1040 this->got_section(symtab
, layout
);
1042 this->plt_
= new Output_data_plt_x86_64(symtab
, layout
, this->got_
,
1044 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1046 | elfcpp::SHF_EXECINSTR
),
1047 this->plt_
, ORDER_PLT
, false);
1049 // Make the sh_info field of .rela.plt point to .plt.
1050 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
1051 rela_plt_os
->set_info_section(this->plt_
->output_section());
1055 // Return the section for TLSDESC relocations.
1057 Target_x86_64::Reloc_section
*
1058 Target_x86_64::rela_tlsdesc_section(Layout
* layout
) const
1060 return this->plt_section()->rela_tlsdesc(layout
);
1063 // Create a PLT entry for a global symbol.
1066 Target_x86_64::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1069 if (gsym
->has_plt_offset())
1072 if (this->plt_
== NULL
)
1073 this->make_plt_section(symtab
, layout
);
1075 this->plt_
->add_entry(gsym
);
1078 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1081 Target_x86_64::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1082 Sized_relobj
<64, false>* relobj
,
1083 unsigned int local_sym_index
)
1085 if (relobj
->local_has_plt_offset(local_sym_index
))
1087 if (this->plt_
== NULL
)
1088 this->make_plt_section(symtab
, layout
);
1089 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(relobj
,
1091 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1094 // Return the number of entries in the PLT.
1097 Target_x86_64::plt_entry_count() const
1099 if (this->plt_
== NULL
)
1101 return this->plt_
->entry_count();
1104 // Return the offset of the first non-reserved PLT entry.
1107 Target_x86_64::first_plt_entry_offset() const
1109 return Output_data_plt_x86_64::first_plt_entry_offset();
1112 // Return the size of each PLT entry.
1115 Target_x86_64::plt_entry_size() const
1117 return Output_data_plt_x86_64::get_plt_entry_size();
1120 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1123 Target_x86_64::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1125 if (this->tls_base_symbol_defined_
)
1128 Output_segment
* tls_segment
= layout
->tls_segment();
1129 if (tls_segment
!= NULL
)
1131 bool is_exec
= parameters
->options().output_is_executable();
1132 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1133 Symbol_table::PREDEFINED
,
1137 elfcpp::STV_HIDDEN
, 0,
1139 ? Symbol::SEGMENT_END
1140 : Symbol::SEGMENT_START
),
1143 this->tls_base_symbol_defined_
= true;
1146 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1149 Target_x86_64::reserve_tlsdesc_entries(Symbol_table
* symtab
,
1152 if (this->plt_
== NULL
)
1153 this->make_plt_section(symtab
, layout
);
1155 if (!this->plt_
->has_tlsdesc_entry())
1157 // Allocate the TLSDESC_GOT entry.
1158 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
1159 unsigned int got_offset
= got
->add_constant(0);
1161 // Allocate the TLSDESC_PLT entry.
1162 this->plt_
->reserve_tlsdesc_entry(got_offset
);
1166 // Create a GOT entry for the TLS module index.
1169 Target_x86_64::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1170 Sized_relobj
<64, false>* object
)
1172 if (this->got_mod_index_offset_
== -1U)
1174 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1175 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
1176 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
1177 unsigned int got_offset
= got
->add_constant(0);
1178 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
1180 got
->add_constant(0);
1181 this->got_mod_index_offset_
= got_offset
;
1183 return this->got_mod_index_offset_
;
1186 // Optimize the TLS relocation type based on what we know about the
1187 // symbol. IS_FINAL is true if the final address of this symbol is
1188 // known at link time.
1190 tls::Tls_optimization
1191 Target_x86_64::optimize_tls_reloc(bool is_final
, int r_type
)
1193 // If we are generating a shared library, then we can't do anything
1195 if (parameters
->options().shared())
1196 return tls::TLSOPT_NONE
;
1200 case elfcpp::R_X86_64_TLSGD
:
1201 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1202 case elfcpp::R_X86_64_TLSDESC_CALL
:
1203 // These are General-Dynamic which permits fully general TLS
1204 // access. Since we know that we are generating an executable,
1205 // we can convert this to Initial-Exec. If we also know that
1206 // this is a local symbol, we can further switch to Local-Exec.
1208 return tls::TLSOPT_TO_LE
;
1209 return tls::TLSOPT_TO_IE
;
1211 case elfcpp::R_X86_64_TLSLD
:
1212 // This is Local-Dynamic, which refers to a local symbol in the
1213 // dynamic TLS block. Since we know that we generating an
1214 // executable, we can switch to Local-Exec.
1215 return tls::TLSOPT_TO_LE
;
1217 case elfcpp::R_X86_64_DTPOFF32
:
1218 case elfcpp::R_X86_64_DTPOFF64
:
1219 // Another Local-Dynamic reloc.
1220 return tls::TLSOPT_TO_LE
;
1222 case elfcpp::R_X86_64_GOTTPOFF
:
1223 // These are Initial-Exec relocs which get the thread offset
1224 // from the GOT. If we know that we are linking against the
1225 // local symbol, we can switch to Local-Exec, which links the
1226 // thread offset into the instruction.
1228 return tls::TLSOPT_TO_LE
;
1229 return tls::TLSOPT_NONE
;
1231 case elfcpp::R_X86_64_TPOFF32
:
1232 // When we already have Local-Exec, there is nothing further we
1234 return tls::TLSOPT_NONE
;
1241 // Report an unsupported relocation against a local symbol.
1244 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj
<64, false>* object
,
1245 unsigned int r_type
)
1247 gold_error(_("%s: unsupported reloc %u against local symbol"),
1248 object
->name().c_str(), r_type
);
1251 // We are about to emit a dynamic relocation of type R_TYPE. If the
1252 // dynamic linker does not support it, issue an error. The GNU linker
1253 // only issues a non-PIC error for an allocated read-only section.
1254 // Here we know the section is allocated, but we don't know that it is
1255 // read-only. But we check for all the relocation types which the
1256 // glibc dynamic linker supports, so it seems appropriate to issue an
1257 // error even if the section is not read-only.
1260 Target_x86_64::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
)
1264 // These are the relocation types supported by glibc for x86_64.
1265 case elfcpp::R_X86_64_RELATIVE
:
1266 case elfcpp::R_X86_64_IRELATIVE
:
1267 case elfcpp::R_X86_64_GLOB_DAT
:
1268 case elfcpp::R_X86_64_JUMP_SLOT
:
1269 case elfcpp::R_X86_64_DTPMOD64
:
1270 case elfcpp::R_X86_64_DTPOFF64
:
1271 case elfcpp::R_X86_64_TPOFF64
:
1272 case elfcpp::R_X86_64_64
:
1273 case elfcpp::R_X86_64_32
:
1274 case elfcpp::R_X86_64_PC32
:
1275 case elfcpp::R_X86_64_COPY
:
1279 // This prevents us from issuing more than one error per reloc
1280 // section. But we can still wind up issuing more than one
1281 // error per object file.
1282 if (this->issued_non_pic_error_
)
1284 gold_assert(parameters
->options().output_is_position_independent());
1285 object
->error(_("requires unsupported dynamic reloc; "
1286 "recompile with -fPIC"));
1287 this->issued_non_pic_error_
= true;
1290 case elfcpp::R_X86_64_NONE
:
1295 // Return whether we need to make a PLT entry for a relocation of the
1296 // given type against a STT_GNU_IFUNC symbol.
1299 Target_x86_64::Scan::reloc_needs_plt_for_ifunc(Sized_relobj
<64, false>* object
,
1300 unsigned int r_type
)
1304 case elfcpp::R_X86_64_NONE
:
1305 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1306 case elfcpp::R_X86_64_GNU_VTENTRY
:
1309 case elfcpp::R_X86_64_64
:
1310 case elfcpp::R_X86_64_32
:
1311 case elfcpp::R_X86_64_32S
:
1312 case elfcpp::R_X86_64_16
:
1313 case elfcpp::R_X86_64_8
:
1314 case elfcpp::R_X86_64_PC64
:
1315 case elfcpp::R_X86_64_PC32
:
1316 case elfcpp::R_X86_64_PC16
:
1317 case elfcpp::R_X86_64_PC8
:
1318 case elfcpp::R_X86_64_PLT32
:
1319 case elfcpp::R_X86_64_GOTPC32
:
1320 case elfcpp::R_X86_64_GOTOFF64
:
1321 case elfcpp::R_X86_64_GOTPC64
:
1322 case elfcpp::R_X86_64_PLTOFF64
:
1323 case elfcpp::R_X86_64_GOT64
:
1324 case elfcpp::R_X86_64_GOT32
:
1325 case elfcpp::R_X86_64_GOTPCREL64
:
1326 case elfcpp::R_X86_64_GOTPCREL
:
1327 case elfcpp::R_X86_64_GOTPLT64
:
1330 case elfcpp::R_X86_64_COPY
:
1331 case elfcpp::R_X86_64_GLOB_DAT
:
1332 case elfcpp::R_X86_64_JUMP_SLOT
:
1333 case elfcpp::R_X86_64_RELATIVE
:
1334 case elfcpp::R_X86_64_IRELATIVE
:
1335 case elfcpp::R_X86_64_TPOFF64
:
1336 case elfcpp::R_X86_64_DTPMOD64
:
1337 case elfcpp::R_X86_64_TLSDESC
:
1338 // We will give an error later.
1341 case elfcpp::R_X86_64_TLSGD
:
1342 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1343 case elfcpp::R_X86_64_TLSDESC_CALL
:
1344 case elfcpp::R_X86_64_TLSLD
:
1345 case elfcpp::R_X86_64_DTPOFF32
:
1346 case elfcpp::R_X86_64_DTPOFF64
:
1347 case elfcpp::R_X86_64_GOTTPOFF
:
1348 case elfcpp::R_X86_64_TPOFF32
:
1349 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1350 object
->name().c_str(), r_type
);
1353 case elfcpp::R_X86_64_SIZE32
:
1354 case elfcpp::R_X86_64_SIZE64
:
1356 // We will give an error later.
1361 // Scan a relocation for a local symbol.
1364 Target_x86_64::Scan::local(Symbol_table
* symtab
,
1366 Target_x86_64
* target
,
1367 Sized_relobj
<64, false>* object
,
1368 unsigned int data_shndx
,
1369 Output_section
* output_section
,
1370 const elfcpp::Rela
<64, false>& reloc
,
1371 unsigned int r_type
,
1372 const elfcpp::Sym
<64, false>& lsym
)
1374 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1375 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1376 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1378 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1379 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1384 case elfcpp::R_X86_64_NONE
:
1385 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1386 case elfcpp::R_X86_64_GNU_VTENTRY
:
1389 case elfcpp::R_X86_64_64
:
1390 // If building a shared library (or a position-independent
1391 // executable), we need to create a dynamic relocation for this
1392 // location. The relocation applied at link time will apply the
1393 // link-time value, so we flag the location with an
1394 // R_X86_64_RELATIVE relocation so the dynamic loader can
1395 // relocate it easily.
1396 if (parameters
->options().output_is_position_independent())
1398 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1399 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1400 rela_dyn
->add_local_relative(object
, r_sym
,
1401 elfcpp::R_X86_64_RELATIVE
,
1402 output_section
, data_shndx
,
1403 reloc
.get_r_offset(),
1404 reloc
.get_r_addend());
1408 case elfcpp::R_X86_64_32
:
1409 case elfcpp::R_X86_64_32S
:
1410 case elfcpp::R_X86_64_16
:
1411 case elfcpp::R_X86_64_8
:
1412 // If building a shared library (or a position-independent
1413 // executable), we need to create a dynamic relocation for this
1414 // location. We can't use an R_X86_64_RELATIVE relocation
1415 // because that is always a 64-bit relocation.
1416 if (parameters
->options().output_is_position_independent())
1418 this->check_non_pic(object
, r_type
);
1420 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1421 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1422 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1423 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1424 data_shndx
, reloc
.get_r_offset(),
1425 reloc
.get_r_addend());
1428 gold_assert(lsym
.get_st_value() == 0);
1429 unsigned int shndx
= lsym
.get_st_shndx();
1431 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1434 object
->error(_("section symbol %u has bad shndx %u"),
1437 rela_dyn
->add_local_section(object
, shndx
,
1438 r_type
, output_section
,
1439 data_shndx
, reloc
.get_r_offset(),
1440 reloc
.get_r_addend());
1445 case elfcpp::R_X86_64_PC64
:
1446 case elfcpp::R_X86_64_PC32
:
1447 case elfcpp::R_X86_64_PC16
:
1448 case elfcpp::R_X86_64_PC8
:
1451 case elfcpp::R_X86_64_PLT32
:
1452 // Since we know this is a local symbol, we can handle this as a
1456 case elfcpp::R_X86_64_GOTPC32
:
1457 case elfcpp::R_X86_64_GOTOFF64
:
1458 case elfcpp::R_X86_64_GOTPC64
:
1459 case elfcpp::R_X86_64_PLTOFF64
:
1460 // We need a GOT section.
1461 target
->got_section(symtab
, layout
);
1462 // For PLTOFF64, we'd normally want a PLT section, but since we
1463 // know this is a local symbol, no PLT is needed.
1466 case elfcpp::R_X86_64_GOT64
:
1467 case elfcpp::R_X86_64_GOT32
:
1468 case elfcpp::R_X86_64_GOTPCREL64
:
1469 case elfcpp::R_X86_64_GOTPCREL
:
1470 case elfcpp::R_X86_64_GOTPLT64
:
1472 // The symbol requires a GOT entry.
1473 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1474 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1476 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1477 // lets function pointers compare correctly with shared
1478 // libraries. Otherwise we would need an IRELATIVE reloc.
1480 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1481 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1483 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1486 // If we are generating a shared object, we need to add a
1487 // dynamic relocation for this symbol's GOT entry.
1488 if (parameters
->options().output_is_position_independent())
1490 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1491 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1492 if (r_type
!= elfcpp::R_X86_64_GOT32
)
1494 unsigned int got_offset
=
1495 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1496 rela_dyn
->add_local_relative(object
, r_sym
,
1497 elfcpp::R_X86_64_RELATIVE
,
1498 got
, got_offset
, 0);
1502 this->check_non_pic(object
, r_type
);
1504 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1505 rela_dyn
->add_local(
1506 object
, r_sym
, r_type
, got
,
1507 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
1511 // For GOTPLT64, we'd normally want a PLT section, but since
1512 // we know this is a local symbol, no PLT is needed.
1516 case elfcpp::R_X86_64_COPY
:
1517 case elfcpp::R_X86_64_GLOB_DAT
:
1518 case elfcpp::R_X86_64_JUMP_SLOT
:
1519 case elfcpp::R_X86_64_RELATIVE
:
1520 case elfcpp::R_X86_64_IRELATIVE
:
1521 // These are outstanding tls relocs, which are unexpected when linking
1522 case elfcpp::R_X86_64_TPOFF64
:
1523 case elfcpp::R_X86_64_DTPMOD64
:
1524 case elfcpp::R_X86_64_TLSDESC
:
1525 gold_error(_("%s: unexpected reloc %u in object file"),
1526 object
->name().c_str(), r_type
);
1529 // These are initial tls relocs, which are expected when linking
1530 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1531 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1532 case elfcpp::R_X86_64_TLSDESC_CALL
:
1533 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1534 case elfcpp::R_X86_64_DTPOFF32
:
1535 case elfcpp::R_X86_64_DTPOFF64
:
1536 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1537 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1539 bool output_is_shared
= parameters
->options().shared();
1540 const tls::Tls_optimization optimized_type
1541 = Target_x86_64::optimize_tls_reloc(!output_is_shared
, r_type
);
1544 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1545 if (optimized_type
== tls::TLSOPT_NONE
)
1547 // Create a pair of GOT entries for the module index and
1548 // dtv-relative offset.
1549 Output_data_got
<64, false>* got
1550 = target
->got_section(symtab
, layout
);
1551 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1552 unsigned int shndx
= lsym
.get_st_shndx();
1554 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1556 object
->error(_("local symbol %u has bad shndx %u"),
1559 got
->add_local_pair_with_rela(object
, r_sym
,
1562 target
->rela_dyn_section(layout
),
1563 elfcpp::R_X86_64_DTPMOD64
, 0);
1565 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1566 unsupported_reloc_local(object
, r_type
);
1569 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
1570 target
->define_tls_base_symbol(symtab
, layout
);
1571 if (optimized_type
== tls::TLSOPT_NONE
)
1573 // Create reserved PLT and GOT entries for the resolver.
1574 target
->reserve_tlsdesc_entries(symtab
, layout
);
1576 // Generate a double GOT entry with an
1577 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
1578 // is resolved lazily, so the GOT entry needs to be in
1579 // an area in .got.plt, not .got. Call got_section to
1580 // make sure the section has been created.
1581 target
->got_section(symtab
, layout
);
1582 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
1583 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1584 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1586 unsigned int got_offset
= got
->add_constant(0);
1587 got
->add_constant(0);
1588 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1590 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
1591 // We store the arguments we need in a vector, and
1592 // use the index into the vector as the parameter
1593 // to pass to the target specific routines.
1594 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
1595 void* arg
= reinterpret_cast<void*>(intarg
);
1596 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
1597 got
, got_offset
, 0);
1600 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1601 unsupported_reloc_local(object
, r_type
);
1604 case elfcpp::R_X86_64_TLSDESC_CALL
:
1607 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1608 if (optimized_type
== tls::TLSOPT_NONE
)
1610 // Create a GOT entry for the module index.
1611 target
->got_mod_index_entry(symtab
, layout
, object
);
1613 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1614 unsupported_reloc_local(object
, r_type
);
1617 case elfcpp::R_X86_64_DTPOFF32
:
1618 case elfcpp::R_X86_64_DTPOFF64
:
1621 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1622 layout
->set_has_static_tls();
1623 if (optimized_type
== tls::TLSOPT_NONE
)
1625 // Create a GOT entry for the tp-relative offset.
1626 Output_data_got
<64, false>* got
1627 = target
->got_section(symtab
, layout
);
1628 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(reloc
.get_r_info());
1629 got
->add_local_with_rela(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
1630 target
->rela_dyn_section(layout
),
1631 elfcpp::R_X86_64_TPOFF64
);
1633 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1634 unsupported_reloc_local(object
, r_type
);
1637 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1638 layout
->set_has_static_tls();
1639 if (output_is_shared
)
1640 unsupported_reloc_local(object
, r_type
);
1649 case elfcpp::R_X86_64_SIZE32
:
1650 case elfcpp::R_X86_64_SIZE64
:
1652 gold_error(_("%s: unsupported reloc %u against local symbol"),
1653 object
->name().c_str(), r_type
);
1659 // Report an unsupported relocation against a global symbol.
1662 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj
<64, false>* object
,
1663 unsigned int r_type
,
1666 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1667 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
1670 // Returns true if this relocation type could be that of a function pointer.
1672 Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type
)
1676 case elfcpp::R_X86_64_64
:
1677 case elfcpp::R_X86_64_32
:
1678 case elfcpp::R_X86_64_32S
:
1679 case elfcpp::R_X86_64_16
:
1680 case elfcpp::R_X86_64_8
:
1681 case elfcpp::R_X86_64_GOT64
:
1682 case elfcpp::R_X86_64_GOT32
:
1683 case elfcpp::R_X86_64_GOTPCREL64
:
1684 case elfcpp::R_X86_64_GOTPCREL
:
1685 case elfcpp::R_X86_64_GOTPLT64
:
1693 // For safe ICF, scan a relocation for a local symbol to check if it
1694 // corresponds to a function pointer being taken. In that case mark
1695 // the function whose pointer was taken as not foldable.
1698 Target_x86_64::Scan::local_reloc_may_be_function_pointer(
1702 Sized_relobj
<64, false>* ,
1705 const elfcpp::Rela
<64, false>& ,
1706 unsigned int r_type
,
1707 const elfcpp::Sym
<64, false>&)
1709 // When building a shared library, do not fold any local symbols as it is
1710 // not possible to distinguish pointer taken versus a call by looking at
1711 // the relocation types.
1712 return (parameters
->options().shared()
1713 || possible_function_pointer_reloc(r_type
));
1716 // For safe ICF, scan a relocation for a global symbol to check if it
1717 // corresponds to a function pointer being taken. In that case mark
1718 // the function whose pointer was taken as not foldable.
1721 Target_x86_64::Scan::global_reloc_may_be_function_pointer(
1725 Sized_relobj
<64, false>* ,
1728 const elfcpp::Rela
<64, false>& ,
1729 unsigned int r_type
,
1732 // When building a shared library, do not fold symbols whose visibility
1733 // is hidden, internal or protected.
1734 return ((parameters
->options().shared()
1735 && (gsym
->visibility() == elfcpp::STV_INTERNAL
1736 || gsym
->visibility() == elfcpp::STV_PROTECTED
1737 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
1738 || possible_function_pointer_reloc(r_type
));
1741 // Scan a relocation for a global symbol.
1744 Target_x86_64::Scan::global(Symbol_table
* symtab
,
1746 Target_x86_64
* target
,
1747 Sized_relobj
<64, false>* object
,
1748 unsigned int data_shndx
,
1749 Output_section
* output_section
,
1750 const elfcpp::Rela
<64, false>& reloc
,
1751 unsigned int r_type
,
1754 // A STT_GNU_IFUNC symbol may require a PLT entry.
1755 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1756 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1757 target
->make_plt_entry(symtab
, layout
, gsym
);
1761 case elfcpp::R_X86_64_NONE
:
1762 case elfcpp::R_X86_64_GNU_VTINHERIT
:
1763 case elfcpp::R_X86_64_GNU_VTENTRY
:
1766 case elfcpp::R_X86_64_64
:
1767 case elfcpp::R_X86_64_32
:
1768 case elfcpp::R_X86_64_32S
:
1769 case elfcpp::R_X86_64_16
:
1770 case elfcpp::R_X86_64_8
:
1772 // Make a PLT entry if necessary.
1773 if (gsym
->needs_plt_entry())
1775 target
->make_plt_entry(symtab
, layout
, gsym
);
1776 // Since this is not a PC-relative relocation, we may be
1777 // taking the address of a function. In that case we need to
1778 // set the entry in the dynamic symbol table to the address of
1780 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
1781 gsym
->set_needs_dynsym_value();
1783 // Make a dynamic relocation if necessary.
1784 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
1786 if (gsym
->may_need_copy_reloc())
1788 target
->copy_reloc(symtab
, layout
, object
,
1789 data_shndx
, output_section
, gsym
, reloc
);
1791 else if (r_type
== elfcpp::R_X86_64_64
1792 && gsym
->type() == elfcpp::STT_GNU_IFUNC
1793 && gsym
->can_use_relative_reloc(false)
1794 && !gsym
->is_from_dynobj()
1795 && !gsym
->is_undefined()
1796 && !gsym
->is_preemptible())
1798 // Use an IRELATIVE reloc for a locally defined
1799 // STT_GNU_IFUNC symbol. This makes a function
1800 // address in a PIE executable match the address in a
1801 // shared library that it links against.
1802 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1803 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
1804 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
1805 output_section
, object
,
1807 reloc
.get_r_offset(),
1808 reloc
.get_r_addend());
1810 else if (r_type
== elfcpp::R_X86_64_64
1811 && gsym
->can_use_relative_reloc(false))
1813 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1814 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
1815 output_section
, object
,
1817 reloc
.get_r_offset(),
1818 reloc
.get_r_addend());
1822 this->check_non_pic(object
, r_type
);
1823 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1824 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1825 data_shndx
, reloc
.get_r_offset(),
1826 reloc
.get_r_addend());
1832 case elfcpp::R_X86_64_PC64
:
1833 case elfcpp::R_X86_64_PC32
:
1834 case elfcpp::R_X86_64_PC16
:
1835 case elfcpp::R_X86_64_PC8
:
1837 // Make a PLT entry if necessary.
1838 if (gsym
->needs_plt_entry())
1839 target
->make_plt_entry(symtab
, layout
, gsym
);
1840 // Make a dynamic relocation if necessary.
1841 int flags
= Symbol::NON_PIC_REF
;
1842 if (gsym
->is_func())
1843 flags
|= Symbol::FUNCTION_CALL
;
1844 if (gsym
->needs_dynamic_reloc(flags
))
1846 if (gsym
->may_need_copy_reloc())
1848 target
->copy_reloc(symtab
, layout
, object
,
1849 data_shndx
, output_section
, gsym
, reloc
);
1853 this->check_non_pic(object
, r_type
);
1854 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1855 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
1856 data_shndx
, reloc
.get_r_offset(),
1857 reloc
.get_r_addend());
1863 case elfcpp::R_X86_64_GOT64
:
1864 case elfcpp::R_X86_64_GOT32
:
1865 case elfcpp::R_X86_64_GOTPCREL64
:
1866 case elfcpp::R_X86_64_GOTPCREL
:
1867 case elfcpp::R_X86_64_GOTPLT64
:
1869 // The symbol requires a GOT entry.
1870 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
1871 if (gsym
->final_value_is_known())
1873 // For a STT_GNU_IFUNC symbol we want the PLT address.
1874 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
1875 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1877 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1881 // If this symbol is not fully resolved, we need to add a
1882 // dynamic relocation for it.
1883 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
1884 if (gsym
->is_from_dynobj()
1885 || gsym
->is_undefined()
1886 || gsym
->is_preemptible()
1887 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
1888 && parameters
->options().output_is_position_independent()))
1889 got
->add_global_with_rela(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
1890 elfcpp::R_X86_64_GLOB_DAT
);
1893 // For a STT_GNU_IFUNC symbol we want to write the PLT
1894 // offset into the GOT, so that function pointer
1895 // comparisons work correctly.
1897 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
1898 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
1901 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
1902 // Tell the dynamic linker to use the PLT address
1903 // when resolving relocations.
1904 if (gsym
->is_from_dynobj()
1905 && !parameters
->options().shared())
1906 gsym
->set_needs_dynsym_value();
1910 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
1911 rela_dyn
->add_global_relative(gsym
,
1912 elfcpp::R_X86_64_RELATIVE
,
1917 // For GOTPLT64, we also need a PLT entry (but only if the
1918 // symbol is not fully resolved).
1919 if (r_type
== elfcpp::R_X86_64_GOTPLT64
1920 && !gsym
->final_value_is_known())
1921 target
->make_plt_entry(symtab
, layout
, gsym
);
1925 case elfcpp::R_X86_64_PLT32
:
1926 // If the symbol is fully resolved, this is just a PC32 reloc.
1927 // Otherwise we need a PLT entry.
1928 if (gsym
->final_value_is_known())
1930 // If building a shared library, we can also skip the PLT entry
1931 // if the symbol is defined in the output file and is protected
1933 if (gsym
->is_defined()
1934 && !gsym
->is_from_dynobj()
1935 && !gsym
->is_preemptible())
1937 target
->make_plt_entry(symtab
, layout
, gsym
);
1940 case elfcpp::R_X86_64_GOTPC32
:
1941 case elfcpp::R_X86_64_GOTOFF64
:
1942 case elfcpp::R_X86_64_GOTPC64
:
1943 case elfcpp::R_X86_64_PLTOFF64
:
1944 // We need a GOT section.
1945 target
->got_section(symtab
, layout
);
1946 // For PLTOFF64, we also need a PLT entry (but only if the
1947 // symbol is not fully resolved).
1948 if (r_type
== elfcpp::R_X86_64_PLTOFF64
1949 && !gsym
->final_value_is_known())
1950 target
->make_plt_entry(symtab
, layout
, gsym
);
1953 case elfcpp::R_X86_64_COPY
:
1954 case elfcpp::R_X86_64_GLOB_DAT
:
1955 case elfcpp::R_X86_64_JUMP_SLOT
:
1956 case elfcpp::R_X86_64_RELATIVE
:
1957 case elfcpp::R_X86_64_IRELATIVE
:
1958 // These are outstanding tls relocs, which are unexpected when linking
1959 case elfcpp::R_X86_64_TPOFF64
:
1960 case elfcpp::R_X86_64_DTPMOD64
:
1961 case elfcpp::R_X86_64_TLSDESC
:
1962 gold_error(_("%s: unexpected reloc %u in object file"),
1963 object
->name().c_str(), r_type
);
1966 // These are initial tls relocs, which are expected for global()
1967 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
1968 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
1969 case elfcpp::R_X86_64_TLSDESC_CALL
:
1970 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
1971 case elfcpp::R_X86_64_DTPOFF32
:
1972 case elfcpp::R_X86_64_DTPOFF64
:
1973 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
1974 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
1976 const bool is_final
= gsym
->final_value_is_known();
1977 const tls::Tls_optimization optimized_type
1978 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
1981 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
1982 if (optimized_type
== tls::TLSOPT_NONE
)
1984 // Create a pair of GOT entries for the module index and
1985 // dtv-relative offset.
1986 Output_data_got
<64, false>* got
1987 = target
->got_section(symtab
, layout
);
1988 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_PAIR
,
1989 target
->rela_dyn_section(layout
),
1990 elfcpp::R_X86_64_DTPMOD64
,
1991 elfcpp::R_X86_64_DTPOFF64
);
1993 else if (optimized_type
== tls::TLSOPT_TO_IE
)
1995 // Create a GOT entry for the tp-relative offset.
1996 Output_data_got
<64, false>* got
1997 = target
->got_section(symtab
, layout
);
1998 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
1999 target
->rela_dyn_section(layout
),
2000 elfcpp::R_X86_64_TPOFF64
);
2002 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2003 unsupported_reloc_global(object
, r_type
, gsym
);
2006 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2007 target
->define_tls_base_symbol(symtab
, layout
);
2008 if (optimized_type
== tls::TLSOPT_NONE
)
2010 // Create reserved PLT and GOT entries for the resolver.
2011 target
->reserve_tlsdesc_entries(symtab
, layout
);
2013 // Create a double GOT entry with an R_X86_64_TLSDESC
2014 // reloc. The R_X86_64_TLSDESC reloc is resolved
2015 // lazily, so the GOT entry needs to be in an area in
2016 // .got.plt, not .got. Call got_section to make sure
2017 // the section has been created.
2018 target
->got_section(symtab
, layout
);
2019 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
2020 Reloc_section
*rt
= target
->rela_tlsdesc_section(layout
);
2021 got
->add_global_pair_with_rela(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2022 elfcpp::R_X86_64_TLSDESC
, 0);
2024 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2026 // Create a GOT entry for the tp-relative offset.
2027 Output_data_got
<64, false>* got
2028 = target
->got_section(symtab
, layout
);
2029 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2030 target
->rela_dyn_section(layout
),
2031 elfcpp::R_X86_64_TPOFF64
);
2033 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2034 unsupported_reloc_global(object
, r_type
, gsym
);
2037 case elfcpp::R_X86_64_TLSDESC_CALL
:
2040 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2041 if (optimized_type
== tls::TLSOPT_NONE
)
2043 // Create a GOT entry for the module index.
2044 target
->got_mod_index_entry(symtab
, layout
, object
);
2046 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2047 unsupported_reloc_global(object
, r_type
, gsym
);
2050 case elfcpp::R_X86_64_DTPOFF32
:
2051 case elfcpp::R_X86_64_DTPOFF64
:
2054 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2055 layout
->set_has_static_tls();
2056 if (optimized_type
== tls::TLSOPT_NONE
)
2058 // Create a GOT entry for the tp-relative offset.
2059 Output_data_got
<64, false>* got
2060 = target
->got_section(symtab
, layout
);
2061 got
->add_global_with_rela(gsym
, GOT_TYPE_TLS_OFFSET
,
2062 target
->rela_dyn_section(layout
),
2063 elfcpp::R_X86_64_TPOFF64
);
2065 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2066 unsupported_reloc_global(object
, r_type
, gsym
);
2069 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2070 layout
->set_has_static_tls();
2071 if (parameters
->options().shared())
2072 unsupported_reloc_local(object
, r_type
);
2081 case elfcpp::R_X86_64_SIZE32
:
2082 case elfcpp::R_X86_64_SIZE64
:
2084 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2085 object
->name().c_str(), r_type
,
2086 gsym
->demangled_name().c_str());
2092 Target_x86_64::gc_process_relocs(Symbol_table
* symtab
,
2094 Sized_relobj
<64, false>* object
,
2095 unsigned int data_shndx
,
2096 unsigned int sh_type
,
2097 const unsigned char* prelocs
,
2099 Output_section
* output_section
,
2100 bool needs_special_offset_handling
,
2101 size_t local_symbol_count
,
2102 const unsigned char* plocal_symbols
)
2105 if (sh_type
== elfcpp::SHT_REL
)
2110 gold::gc_process_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2111 Target_x86_64::Scan
,
2112 Target_x86_64::Relocatable_size_for_reloc
>(
2121 needs_special_offset_handling
,
2126 // Scan relocations for a section.
2129 Target_x86_64::scan_relocs(Symbol_table
* symtab
,
2131 Sized_relobj
<64, false>* object
,
2132 unsigned int data_shndx
,
2133 unsigned int sh_type
,
2134 const unsigned char* prelocs
,
2136 Output_section
* output_section
,
2137 bool needs_special_offset_handling
,
2138 size_t local_symbol_count
,
2139 const unsigned char* plocal_symbols
)
2141 if (sh_type
== elfcpp::SHT_REL
)
2143 gold_error(_("%s: unsupported REL reloc section"),
2144 object
->name().c_str());
2148 gold::scan_relocs
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2149 Target_x86_64::Scan
>(
2158 needs_special_offset_handling
,
2163 // Finalize the sections.
2166 Target_x86_64::do_finalize_sections(
2168 const Input_objects
*,
2169 Symbol_table
* symtab
)
2171 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2173 : this->plt_
->rela_plt());
2174 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
2175 this->rela_dyn_
, true, false);
2177 // Fill in some more dynamic tags.
2178 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
2181 if (this->plt_
!= NULL
2182 && this->plt_
->output_section() != NULL
2183 && this->plt_
->has_tlsdesc_entry())
2185 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
2186 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
2187 this->got_
->finalize_data_size();
2188 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
2189 this->plt_
, plt_offset
);
2190 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
2191 this->got_
, got_offset
);
2195 // Emit any relocs we saved in an attempt to avoid generating COPY
2197 if (this->copy_relocs_
.any_saved_relocs())
2198 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
2200 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2201 // the .got.plt section.
2202 Symbol
* sym
= this->global_offset_table_
;
2205 uint64_t data_size
= this->got_plt_
->current_data_size();
2206 symtab
->get_sized_symbol
<64>(sym
)->set_symsize(data_size
);
2210 // Perform a relocation.
2213 Target_x86_64::Relocate::relocate(const Relocate_info
<64, false>* relinfo
,
2214 Target_x86_64
* target
,
2217 const elfcpp::Rela
<64, false>& rela
,
2218 unsigned int r_type
,
2219 const Sized_symbol
<64>* gsym
,
2220 const Symbol_value
<64>* psymval
,
2221 unsigned char* view
,
2222 elfcpp::Elf_types
<64>::Elf_Addr address
,
2223 section_size_type view_size
)
2225 if (this->skip_call_tls_get_addr_
)
2227 if ((r_type
!= elfcpp::R_X86_64_PLT32
2228 && r_type
!= elfcpp::R_X86_64_PC32
)
2230 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
2232 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2233 _("missing expected TLS relocation"));
2237 this->skip_call_tls_get_addr_
= false;
2242 const Sized_relobj
<64, false>* object
= relinfo
->object
;
2244 // Pick the value to use for symbols defined in the PLT.
2245 Symbol_value
<64> symval
;
2247 && gsym
->use_plt_offset(r_type
== elfcpp::R_X86_64_PC64
2248 || r_type
== elfcpp::R_X86_64_PC32
2249 || r_type
== elfcpp::R_X86_64_PC16
2250 || r_type
== elfcpp::R_X86_64_PC8
))
2252 symval
.set_output_value(target
->plt_section()->address()
2253 + gsym
->plt_offset());
2256 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2258 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2259 if (object
->local_has_plt_offset(r_sym
))
2261 symval
.set_output_value(target
->plt_section()->address()
2262 + object
->local_plt_offset(r_sym
));
2267 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2269 // Get the GOT offset if needed.
2270 // The GOT pointer points to the end of the GOT section.
2271 // We need to subtract the size of the GOT section to get
2272 // the actual offset to use in the relocation.
2273 bool have_got_offset
= false;
2274 unsigned int got_offset
= 0;
2277 case elfcpp::R_X86_64_GOT32
:
2278 case elfcpp::R_X86_64_GOT64
:
2279 case elfcpp::R_X86_64_GOTPLT64
:
2280 case elfcpp::R_X86_64_GOTPCREL
:
2281 case elfcpp::R_X86_64_GOTPCREL64
:
2284 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2285 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
2289 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2290 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2291 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2292 - target
->got_size());
2294 have_got_offset
= true;
2303 case elfcpp::R_X86_64_NONE
:
2304 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2305 case elfcpp::R_X86_64_GNU_VTENTRY
:
2308 case elfcpp::R_X86_64_64
:
2309 Relocate_functions
<64, false>::rela64(view
, object
, psymval
, addend
);
2312 case elfcpp::R_X86_64_PC64
:
2313 Relocate_functions
<64, false>::pcrela64(view
, object
, psymval
, addend
,
2317 case elfcpp::R_X86_64_32
:
2318 // FIXME: we need to verify that value + addend fits into 32 bits:
2319 // uint64_t x = value + addend;
2320 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
2321 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
2322 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
2325 case elfcpp::R_X86_64_32S
:
2326 // FIXME: we need to verify that value + addend fits into 32 bits:
2327 // int64_t x = value + addend; // note this quantity is signed!
2328 // x == static_cast<int64_t>(static_cast<int32_t>(x))
2329 Relocate_functions
<64, false>::rela32(view
, object
, psymval
, addend
);
2332 case elfcpp::R_X86_64_PC32
:
2333 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2337 case elfcpp::R_X86_64_16
:
2338 Relocate_functions
<64, false>::rela16(view
, object
, psymval
, addend
);
2341 case elfcpp::R_X86_64_PC16
:
2342 Relocate_functions
<64, false>::pcrela16(view
, object
, psymval
, addend
,
2346 case elfcpp::R_X86_64_8
:
2347 Relocate_functions
<64, false>::rela8(view
, object
, psymval
, addend
);
2350 case elfcpp::R_X86_64_PC8
:
2351 Relocate_functions
<64, false>::pcrela8(view
, object
, psymval
, addend
,
2355 case elfcpp::R_X86_64_PLT32
:
2356 gold_assert(gsym
== NULL
2357 || gsym
->has_plt_offset()
2358 || gsym
->final_value_is_known()
2359 || (gsym
->is_defined()
2360 && !gsym
->is_from_dynobj()
2361 && !gsym
->is_preemptible()));
2362 // Note: while this code looks the same as for R_X86_64_PC32, it
2363 // behaves differently because psymval was set to point to
2364 // the PLT entry, rather than the symbol, in Scan::global().
2365 Relocate_functions
<64, false>::pcrela32(view
, object
, psymval
, addend
,
2369 case elfcpp::R_X86_64_PLTOFF64
:
2372 gold_assert(gsym
->has_plt_offset()
2373 || gsym
->final_value_is_known());
2374 elfcpp::Elf_types
<64>::Elf_Addr got_address
;
2375 got_address
= target
->got_section(NULL
, NULL
)->address();
2376 Relocate_functions
<64, false>::rela64(view
, object
, psymval
,
2377 addend
- got_address
);
2380 case elfcpp::R_X86_64_GOT32
:
2381 gold_assert(have_got_offset
);
2382 Relocate_functions
<64, false>::rela32(view
, got_offset
, addend
);
2385 case elfcpp::R_X86_64_GOTPC32
:
2388 elfcpp::Elf_types
<64>::Elf_Addr value
;
2389 value
= target
->got_plt_section()->address();
2390 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2394 case elfcpp::R_X86_64_GOT64
:
2395 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
2396 // Since we always add a PLT entry, this is equivalent.
2397 case elfcpp::R_X86_64_GOTPLT64
:
2398 gold_assert(have_got_offset
);
2399 Relocate_functions
<64, false>::rela64(view
, got_offset
, addend
);
2402 case elfcpp::R_X86_64_GOTPC64
:
2405 elfcpp::Elf_types
<64>::Elf_Addr value
;
2406 value
= target
->got_plt_section()->address();
2407 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
2411 case elfcpp::R_X86_64_GOTOFF64
:
2413 elfcpp::Elf_types
<64>::Elf_Addr value
;
2414 value
= (psymval
->value(object
, 0)
2415 - target
->got_plt_section()->address());
2416 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2420 case elfcpp::R_X86_64_GOTPCREL
:
2422 gold_assert(have_got_offset
);
2423 elfcpp::Elf_types
<64>::Elf_Addr value
;
2424 value
= target
->got_plt_section()->address() + got_offset
;
2425 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2429 case elfcpp::R_X86_64_GOTPCREL64
:
2431 gold_assert(have_got_offset
);
2432 elfcpp::Elf_types
<64>::Elf_Addr value
;
2433 value
= target
->got_plt_section()->address() + got_offset
;
2434 Relocate_functions
<64, false>::pcrela64(view
, value
, addend
, address
);
2438 case elfcpp::R_X86_64_COPY
:
2439 case elfcpp::R_X86_64_GLOB_DAT
:
2440 case elfcpp::R_X86_64_JUMP_SLOT
:
2441 case elfcpp::R_X86_64_RELATIVE
:
2442 case elfcpp::R_X86_64_IRELATIVE
:
2443 // These are outstanding tls relocs, which are unexpected when linking
2444 case elfcpp::R_X86_64_TPOFF64
:
2445 case elfcpp::R_X86_64_DTPMOD64
:
2446 case elfcpp::R_X86_64_TLSDESC
:
2447 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2448 _("unexpected reloc %u in object file"),
2452 // These are initial tls relocs, which are expected when linking
2453 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2454 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2455 case elfcpp::R_X86_64_TLSDESC_CALL
:
2456 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2457 case elfcpp::R_X86_64_DTPOFF32
:
2458 case elfcpp::R_X86_64_DTPOFF64
:
2459 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2460 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2461 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
2462 view
, address
, view_size
);
2465 case elfcpp::R_X86_64_SIZE32
:
2466 case elfcpp::R_X86_64_SIZE64
:
2468 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2469 _("unsupported reloc %u"),
2477 // Perform a TLS relocation.
2480 Target_x86_64::Relocate::relocate_tls(const Relocate_info
<64, false>* relinfo
,
2481 Target_x86_64
* target
,
2483 const elfcpp::Rela
<64, false>& rela
,
2484 unsigned int r_type
,
2485 const Sized_symbol
<64>* gsym
,
2486 const Symbol_value
<64>* psymval
,
2487 unsigned char* view
,
2488 elfcpp::Elf_types
<64>::Elf_Addr address
,
2489 section_size_type view_size
)
2491 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2493 const Sized_relobj
<64, false>* object
= relinfo
->object
;
2494 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2496 elfcpp::Elf_types
<64>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
2498 const bool is_final
= (gsym
== NULL
2499 ? !parameters
->options().shared()
2500 : gsym
->final_value_is_known());
2501 const tls::Tls_optimization optimized_type
2502 = Target_x86_64::optimize_tls_reloc(is_final
, r_type
);
2505 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2506 this->saw_tls_block_reloc_
= true;
2507 if (optimized_type
== tls::TLSOPT_TO_LE
)
2509 gold_assert(tls_segment
!= NULL
);
2510 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2511 rela
, r_type
, value
, view
,
2517 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2518 ? GOT_TYPE_TLS_OFFSET
2519 : GOT_TYPE_TLS_PAIR
);
2520 unsigned int got_offset
;
2523 gold_assert(gsym
->has_got_offset(got_type
));
2524 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2528 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2529 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2530 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2531 - target
->got_size());
2533 if (optimized_type
== tls::TLSOPT_TO_IE
)
2535 gold_assert(tls_segment
!= NULL
);
2536 value
= target
->got_plt_section()->address() + got_offset
;
2537 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2538 value
, view
, address
, view_size
);
2541 else if (optimized_type
== tls::TLSOPT_NONE
)
2543 // Relocate the field with the offset of the pair of GOT
2545 value
= target
->got_plt_section()->address() + got_offset
;
2546 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2551 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2552 _("unsupported reloc %u"), r_type
);
2555 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2556 case elfcpp::R_X86_64_TLSDESC_CALL
:
2557 this->saw_tls_block_reloc_
= true;
2558 if (optimized_type
== tls::TLSOPT_TO_LE
)
2560 gold_assert(tls_segment
!= NULL
);
2561 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2562 rela
, r_type
, value
, view
,
2568 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2569 ? GOT_TYPE_TLS_OFFSET
2570 : GOT_TYPE_TLS_DESC
);
2571 unsigned int got_offset
= 0;
2572 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
2573 && optimized_type
== tls::TLSOPT_NONE
)
2575 // We created GOT entries in the .got.tlsdesc portion of
2576 // the .got.plt section, but the offset stored in the
2577 // symbol is the offset within .got.tlsdesc.
2578 got_offset
= (target
->got_size()
2579 + target
->got_plt_section()->data_size());
2583 gold_assert(gsym
->has_got_offset(got_type
));
2584 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2588 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2589 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2590 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2591 - target
->got_size());
2593 if (optimized_type
== tls::TLSOPT_TO_IE
)
2595 gold_assert(tls_segment
!= NULL
);
2596 value
= target
->got_plt_section()->address() + got_offset
;
2597 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
,
2598 rela
, r_type
, value
, view
, address
,
2602 else if (optimized_type
== tls::TLSOPT_NONE
)
2604 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2606 // Relocate the field with the offset of the pair of GOT
2608 value
= target
->got_plt_section()->address() + got_offset
;
2609 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2615 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2616 _("unsupported reloc %u"), r_type
);
2619 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2620 this->saw_tls_block_reloc_
= true;
2621 if (optimized_type
== tls::TLSOPT_TO_LE
)
2623 gold_assert(tls_segment
!= NULL
);
2624 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
2625 value
, view
, view_size
);
2628 else if (optimized_type
== tls::TLSOPT_NONE
)
2630 // Relocate the field with the offset of the GOT entry for
2631 // the module index.
2632 unsigned int got_offset
;
2633 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
2634 - target
->got_size());
2635 value
= target
->got_plt_section()->address() + got_offset
;
2636 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
,
2640 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2641 _("unsupported reloc %u"), r_type
);
2644 case elfcpp::R_X86_64_DTPOFF32
:
2645 if (optimized_type
== tls::TLSOPT_TO_LE
)
2647 // This relocation type is used in debugging information.
2648 // In that case we need to not optimize the value. If we
2649 // haven't seen a TLSLD reloc, then we assume we should not
2650 // optimize this reloc.
2651 if (this->saw_tls_block_reloc_
)
2653 gold_assert(tls_segment
!= NULL
);
2654 value
-= tls_segment
->memsz();
2657 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2660 case elfcpp::R_X86_64_DTPOFF64
:
2661 if (optimized_type
== tls::TLSOPT_TO_LE
)
2663 // See R_X86_64_DTPOFF32, just above, for why we test this.
2664 if (this->saw_tls_block_reloc_
)
2666 gold_assert(tls_segment
!= NULL
);
2667 value
-= tls_segment
->memsz();
2670 Relocate_functions
<64, false>::rela64(view
, value
, addend
);
2673 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2674 if (optimized_type
== tls::TLSOPT_TO_LE
)
2676 gold_assert(tls_segment
!= NULL
);
2677 Target_x86_64::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
2678 rela
, r_type
, value
, view
,
2682 else if (optimized_type
== tls::TLSOPT_NONE
)
2684 // Relocate the field with the offset of the GOT entry for
2685 // the tp-relative offset of the symbol.
2686 unsigned int got_offset
;
2689 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
2690 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
2691 - target
->got_size());
2695 unsigned int r_sym
= elfcpp::elf_r_sym
<64>(rela
.get_r_info());
2696 gold_assert(object
->local_has_got_offset(r_sym
,
2697 GOT_TYPE_TLS_OFFSET
));
2698 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
2699 - target
->got_size());
2701 value
= target
->got_plt_section()->address() + got_offset
;
2702 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2705 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
2706 _("unsupported reloc type %u"),
2710 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2711 value
-= tls_segment
->memsz();
2712 Relocate_functions
<64, false>::rela32(view
, value
, addend
);
2717 // Do a relocation in which we convert a TLS General-Dynamic to an
2721 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info
<64, false>* relinfo
,
2724 const elfcpp::Rela
<64, false>& rela
,
2726 elfcpp::Elf_types
<64>::Elf_Addr value
,
2727 unsigned char* view
,
2728 elfcpp::Elf_types
<64>::Elf_Addr address
,
2729 section_size_type view_size
)
2731 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2732 // .word 0x6666; rex64; call __tls_get_addr
2733 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2735 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2736 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2738 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2739 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2740 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2741 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2743 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2745 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2746 Relocate_functions
<64, false>::pcrela32(view
+ 8, value
, addend
- 8, address
);
2748 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2750 this->skip_call_tls_get_addr_
= true;
2753 // Do a relocation in which we convert a TLS General-Dynamic to a
2757 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info
<64, false>* relinfo
,
2759 Output_segment
* tls_segment
,
2760 const elfcpp::Rela
<64, false>& rela
,
2762 elfcpp::Elf_types
<64>::Elf_Addr value
,
2763 unsigned char* view
,
2764 section_size_type view_size
)
2766 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2767 // .word 0x6666; rex64; call __tls_get_addr
2768 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2770 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -4);
2771 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
2773 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2774 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
2775 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2776 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0));
2778 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2780 value
-= tls_segment
->memsz();
2781 Relocate_functions
<64, false>::rela32(view
+ 8, value
, 0);
2783 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2785 this->skip_call_tls_get_addr_
= true;
2788 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2791 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2792 const Relocate_info
<64, false>* relinfo
,
2795 const elfcpp::Rela
<64, false>& rela
,
2796 unsigned int r_type
,
2797 elfcpp::Elf_types
<64>::Elf_Addr value
,
2798 unsigned char* view
,
2799 elfcpp::Elf_types
<64>::Elf_Addr address
,
2800 section_size_type view_size
)
2802 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2804 // leaq foo@tlsdesc(%rip), %rax
2805 // ==> movq foo@gottpoff(%rip), %rax
2806 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2807 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2808 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2809 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2811 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
2812 Relocate_functions
<64, false>::pcrela32(view
, value
, addend
, address
);
2816 // call *foo@tlscall(%rax)
2818 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2819 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2820 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2821 view
[0] == 0xff && view
[1] == 0x10);
2827 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2830 Target_x86_64::Relocate::tls_desc_gd_to_le(
2831 const Relocate_info
<64, false>* relinfo
,
2833 Output_segment
* tls_segment
,
2834 const elfcpp::Rela
<64, false>& rela
,
2835 unsigned int r_type
,
2836 elfcpp::Elf_types
<64>::Elf_Addr value
,
2837 unsigned char* view
,
2838 section_size_type view_size
)
2840 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
2842 // leaq foo@tlsdesc(%rip), %rax
2843 // ==> movq foo@tpoff, %rax
2844 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2845 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2846 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2847 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
2850 value
-= tls_segment
->memsz();
2851 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2855 // call *foo@tlscall(%rax)
2857 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
2858 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
2859 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2860 view
[0] == 0xff && view
[1] == 0x10);
2867 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info
<64, false>* relinfo
,
2870 const elfcpp::Rela
<64, false>& rela
,
2872 elfcpp::Elf_types
<64>::Elf_Addr
,
2873 unsigned char* view
,
2874 section_size_type view_size
)
2876 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2877 // ... leq foo@dtpoff(%rax),%reg
2878 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2880 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2881 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
2883 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
2884 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
2886 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(), view
[4] == 0xe8);
2888 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2890 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2892 this->skip_call_tls_get_addr_
= true;
2895 // Do a relocation in which we convert a TLS Initial-Exec to a
2899 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info
<64, false>* relinfo
,
2901 Output_segment
* tls_segment
,
2902 const elfcpp::Rela
<64, false>& rela
,
2904 elfcpp::Elf_types
<64>::Elf_Addr value
,
2905 unsigned char* view
,
2906 section_size_type view_size
)
2908 // We need to examine the opcodes to figure out which instruction we
2911 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
2912 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
2914 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
2915 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
2917 unsigned char op1
= view
[-3];
2918 unsigned char op2
= view
[-2];
2919 unsigned char op3
= view
[-1];
2920 unsigned char reg
= op3
>> 3;
2928 view
[-1] = 0xc0 | reg
;
2932 // Special handling for %rsp.
2936 view
[-1] = 0xc0 | reg
;
2944 view
[-1] = 0x80 | reg
| (reg
<< 3);
2947 value
-= tls_segment
->memsz();
2948 Relocate_functions
<64, false>::rela32(view
, value
, 0);
2951 // Relocate section data.
2954 Target_x86_64::relocate_section(
2955 const Relocate_info
<64, false>* relinfo
,
2956 unsigned int sh_type
,
2957 const unsigned char* prelocs
,
2959 Output_section
* output_section
,
2960 bool needs_special_offset_handling
,
2961 unsigned char* view
,
2962 elfcpp::Elf_types
<64>::Elf_Addr address
,
2963 section_size_type view_size
,
2964 const Reloc_symbol_changes
* reloc_symbol_changes
)
2966 gold_assert(sh_type
== elfcpp::SHT_RELA
);
2968 gold::relocate_section
<64, false, Target_x86_64
, elfcpp::SHT_RELA
,
2969 Target_x86_64::Relocate
>(
2975 needs_special_offset_handling
,
2979 reloc_symbol_changes
);
2982 // Return the size of a relocation while scanning during a relocatable
2986 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2987 unsigned int r_type
,
2992 case elfcpp::R_X86_64_NONE
:
2993 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2994 case elfcpp::R_X86_64_GNU_VTENTRY
:
2995 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2996 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2997 case elfcpp::R_X86_64_TLSDESC_CALL
:
2998 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2999 case elfcpp::R_X86_64_DTPOFF32
:
3000 case elfcpp::R_X86_64_DTPOFF64
:
3001 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3002 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3005 case elfcpp::R_X86_64_64
:
3006 case elfcpp::R_X86_64_PC64
:
3007 case elfcpp::R_X86_64_GOTOFF64
:
3008 case elfcpp::R_X86_64_GOTPC64
:
3009 case elfcpp::R_X86_64_PLTOFF64
:
3010 case elfcpp::R_X86_64_GOT64
:
3011 case elfcpp::R_X86_64_GOTPCREL64
:
3012 case elfcpp::R_X86_64_GOTPCREL
:
3013 case elfcpp::R_X86_64_GOTPLT64
:
3016 case elfcpp::R_X86_64_32
:
3017 case elfcpp::R_X86_64_32S
:
3018 case elfcpp::R_X86_64_PC32
:
3019 case elfcpp::R_X86_64_PLT32
:
3020 case elfcpp::R_X86_64_GOTPC32
:
3021 case elfcpp::R_X86_64_GOT32
:
3024 case elfcpp::R_X86_64_16
:
3025 case elfcpp::R_X86_64_PC16
:
3028 case elfcpp::R_X86_64_8
:
3029 case elfcpp::R_X86_64_PC8
:
3032 case elfcpp::R_X86_64_COPY
:
3033 case elfcpp::R_X86_64_GLOB_DAT
:
3034 case elfcpp::R_X86_64_JUMP_SLOT
:
3035 case elfcpp::R_X86_64_RELATIVE
:
3036 case elfcpp::R_X86_64_IRELATIVE
:
3037 // These are outstanding tls relocs, which are unexpected when linking
3038 case elfcpp::R_X86_64_TPOFF64
:
3039 case elfcpp::R_X86_64_DTPMOD64
:
3040 case elfcpp::R_X86_64_TLSDESC
:
3041 object
->error(_("unexpected reloc %u in object file"), r_type
);
3044 case elfcpp::R_X86_64_SIZE32
:
3045 case elfcpp::R_X86_64_SIZE64
:
3047 object
->error(_("unsupported reloc %u against local symbol"), r_type
);
3052 // Scan the relocs during a relocatable link.
3055 Target_x86_64::scan_relocatable_relocs(Symbol_table
* symtab
,
3057 Sized_relobj
<64, false>* object
,
3058 unsigned int data_shndx
,
3059 unsigned int sh_type
,
3060 const unsigned char* prelocs
,
3062 Output_section
* output_section
,
3063 bool needs_special_offset_handling
,
3064 size_t local_symbol_count
,
3065 const unsigned char* plocal_symbols
,
3066 Relocatable_relocs
* rr
)
3068 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3070 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_RELA
,
3071 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3073 gold::scan_relocatable_relocs
<64, false, elfcpp::SHT_RELA
,
3074 Scan_relocatable_relocs
>(
3082 needs_special_offset_handling
,
3088 // Relocate a section during a relocatable link.
3091 Target_x86_64::relocate_for_relocatable(
3092 const Relocate_info
<64, false>* relinfo
,
3093 unsigned int sh_type
,
3094 const unsigned char* prelocs
,
3096 Output_section
* output_section
,
3097 off_t offset_in_output_section
,
3098 const Relocatable_relocs
* rr
,
3099 unsigned char* view
,
3100 elfcpp::Elf_types
<64>::Elf_Addr view_address
,
3101 section_size_type view_size
,
3102 unsigned char* reloc_view
,
3103 section_size_type reloc_view_size
)
3105 gold_assert(sh_type
== elfcpp::SHT_RELA
);
3107 gold::relocate_for_relocatable
<64, false, elfcpp::SHT_RELA
>(
3112 offset_in_output_section
,
3121 // Return the value to use for a dynamic which requires special
3122 // treatment. This is how we support equality comparisons of function
3123 // pointers across shared library boundaries, as described in the
3124 // processor specific ABI supplement.
3127 Target_x86_64::do_dynsym_value(const Symbol
* gsym
) const
3129 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3130 return this->plt_section()->address() + gsym
->plt_offset();
3133 // Return a string used to fill a code section with nops to take up
3134 // the specified length.
3137 Target_x86_64::do_code_fill(section_size_type length
) const
3141 // Build a jmpq instruction to skip over the bytes.
3142 unsigned char jmp
[5];
3144 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3145 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3146 + std::string(length
- 5, '\0'));
3149 // Nop sequences of various lengths.
3150 const char nop1
[1] = { 0x90 }; // nop
3151 const char nop2
[2] = { 0x66, 0x90 }; // xchg %ax %ax
3152 const char nop3
[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
3153 const char nop4
[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
3154 const char nop5
[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
3156 const char nop6
[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
3158 const char nop7
[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
3160 const char nop8
[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
3161 0x00, 0x00, 0x00, 0x00 };
3162 const char nop9
[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
3163 0x00, 0x00, 0x00, 0x00,
3165 const char nop10
[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
3166 0x84, 0x00, 0x00, 0x00,
3168 const char nop11
[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
3169 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3171 const char nop12
[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
3172 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
3173 0x00, 0x00, 0x00, 0x00 };
3174 const char nop13
[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3175 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
3176 0x00, 0x00, 0x00, 0x00,
3178 const char nop14
[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3179 0x66, 0x2e, 0x0f, 0x1f, // data16
3180 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3182 const char nop15
[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3183 0x66, 0x66, 0x2e, 0x0f, // data16; data16
3184 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3187 const char* nops
[16] = {
3189 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3190 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3193 return std::string(nops
[length
], length
);
3196 // Return the addend to use for a target specific relocation. The
3197 // only target specific relocation is R_X86_64_TLSDESC for a local
3198 // symbol. We want to set the addend is the offset of the local
3199 // symbol in the TLS segment.
3202 Target_x86_64::do_reloc_addend(void* arg
, unsigned int r_type
,
3205 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
3206 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
3207 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
3208 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
3209 const Symbol_value
<64>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
3210 gold_assert(psymval
->is_tls_symbol());
3211 // The value of a TLS symbol is the offset in the TLS segment.
3212 return psymval
->value(ti
.object
, 0);
3215 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3216 // compiled with -fstack-split. The function calls non-stack-split
3217 // code. We have to change the function so that it always ensures
3218 // that it has enough stack space to run some random function.
3221 Target_x86_64::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3222 section_offset_type fnoffset
,
3223 section_size_type fnsize
,
3224 unsigned char* view
,
3225 section_size_type view_size
,
3227 std::string
* to
) const
3229 // The function starts with a comparison of the stack pointer and a
3230 // field in the TCB. This is followed by a jump.
3233 if (this->match_view(view
, view_size
, fnoffset
, "\x64\x48\x3b\x24\x25", 5)
3236 // We will call __morestack if the carry flag is set after this
3237 // comparison. We turn the comparison into an stc instruction
3239 view
[fnoffset
] = '\xf9';
3240 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 8);
3242 // lea NN(%rsp),%r10
3243 // lea NN(%rsp),%r11
3244 else if ((this->match_view(view
, view_size
, fnoffset
,
3245 "\x4c\x8d\x94\x24", 4)
3246 || this->match_view(view
, view_size
, fnoffset
,
3247 "\x4c\x8d\x9c\x24", 4))
3250 // This is loading an offset from the stack pointer for a
3251 // comparison. The offset is negative, so we decrease the
3252 // offset by the amount of space we need for the stack. This
3253 // means we will avoid calling __morestack if there happens to
3254 // be plenty of space on the stack already.
3255 unsigned char* pval
= view
+ fnoffset
+ 4;
3256 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3257 val
-= parameters
->options().split_stack_adjust_size();
3258 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3262 if (!object
->has_no_split_stack())
3263 object
->error(_("failed to match split-stack sequence at "
3264 "section %u offset %0zx"),
3265 shndx
, static_cast<size_t>(fnoffset
));
3269 // We have to change the function so that it calls
3270 // __morestack_non_split instead of __morestack. The former will
3271 // allocate additional stack space.
3272 *from
= "__morestack";
3273 *to
= "__morestack_non_split";
3276 // The selector for x86_64 object files.
3278 class Target_selector_x86_64
: public Target_selector_freebsd
3281 Target_selector_x86_64()
3282 : Target_selector_freebsd(elfcpp::EM_X86_64
, 64, false, "elf64-x86-64",
3283 "elf64-x86-64-freebsd")
3287 do_instantiate_target()
3288 { return new Target_x86_64(); }
3292 Target_selector_x86_64 target_selector_x86_64
;
3294 } // End anonymous namespace.