1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright (C) 2006-2017 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.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
51 // A class to handle the .got.plt section.
53 class Output_data_got_plt_x86_64
: public Output_section_data_build
56 Output_data_got_plt_x86_64(Layout
* layout
)
57 : Output_section_data_build(8),
61 Output_data_got_plt_x86_64(Layout
* layout
, off_t data_size
)
62 : Output_section_data_build(data_size
, 8),
67 // Write out the PLT data.
69 do_write(Output_file
*);
71 // Write to a map file.
73 do_print_to_mapfile(Mapfile
* mapfile
) const
74 { mapfile
->print_output_data(this, "** GOT PLT"); }
77 // A pointer to the Layout class, so that we can find the .dynamic
78 // section when we write out the GOT PLT section.
82 // A class to handle the PLT data.
83 // This is an abstract base class that handles most of the linker details
84 // but does not know the actual contents of PLT entries. The derived
85 // classes below fill in those details.
88 class Output_data_plt_x86_64
: public Output_section_data
91 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, size
, false> Reloc_section
;
93 Output_data_plt_x86_64(Layout
* layout
, uint64_t addralign
,
94 Output_data_got
<64, false>* got
,
95 Output_data_got_plt_x86_64
* got_plt
,
96 Output_data_space
* got_irelative
)
97 : Output_section_data(addralign
), tlsdesc_rel_(NULL
),
98 irelative_rel_(NULL
), got_(got
), got_plt_(got_plt
),
99 got_irelative_(got_irelative
), count_(0), irelative_count_(0),
100 tlsdesc_got_offset_(-1U), free_list_()
101 { this->init(layout
); }
103 Output_data_plt_x86_64(Layout
* layout
, uint64_t plt_entry_size
,
104 Output_data_got
<64, false>* got
,
105 Output_data_got_plt_x86_64
* got_plt
,
106 Output_data_space
* got_irelative
,
107 unsigned int plt_count
)
108 : Output_section_data((plt_count
+ 1) * plt_entry_size
,
109 plt_entry_size
, false),
110 tlsdesc_rel_(NULL
), irelative_rel_(NULL
), got_(got
),
111 got_plt_(got_plt
), got_irelative_(got_irelative
), count_(plt_count
),
112 irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
116 // Initialize the free list and reserve the first entry.
117 this->free_list_
.init((plt_count
+ 1) * plt_entry_size
, false);
118 this->free_list_
.remove(0, plt_entry_size
);
121 // Initialize the PLT section.
123 init(Layout
* layout
);
125 // Add an entry to the PLT.
127 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
129 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
131 add_local_ifunc_entry(Symbol_table
* symtab
, Layout
*,
132 Sized_relobj_file
<size
, false>* relobj
,
133 unsigned int local_sym_index
);
135 // Add the relocation for a PLT entry.
137 add_relocation(Symbol_table
*, Layout
*, Symbol
* gsym
,
138 unsigned int got_offset
);
140 // Add the reserved TLSDESC_PLT entry to the PLT.
142 reserve_tlsdesc_entry(unsigned int got_offset
)
143 { this->tlsdesc_got_offset_
= got_offset
; }
145 // Return true if a TLSDESC_PLT entry has been reserved.
147 has_tlsdesc_entry() const
148 { return this->tlsdesc_got_offset_
!= -1U; }
150 // Return the GOT offset for the reserved TLSDESC_PLT entry.
152 get_tlsdesc_got_offset() const
153 { return this->tlsdesc_got_offset_
; }
155 // Return the offset of the reserved TLSDESC_PLT entry.
157 get_tlsdesc_plt_offset() const
159 return ((this->count_
+ this->irelative_count_
+ 1)
160 * this->get_plt_entry_size());
163 // Return the .rela.plt section data.
166 { return this->rel_
; }
168 // Return where the TLSDESC relocations should go.
170 rela_tlsdesc(Layout
*);
172 // Return where the IRELATIVE relocations should go in the PLT
175 rela_irelative(Symbol_table
*, Layout
*);
177 // Return whether we created a section for IRELATIVE relocations.
179 has_irelative_section() const
180 { return this->irelative_rel_
!= NULL
; }
182 // Get count of regular PLT entries.
184 regular_count() const
185 { return this->count_
; }
187 // Return the total number of PLT entries.
190 { return this->count_
+ this->irelative_count_
; }
192 // Return the offset of the first non-reserved PLT entry.
194 first_plt_entry_offset()
195 { return this->get_plt_entry_size(); }
197 // Return the size of a PLT entry.
199 get_plt_entry_size() const
200 { return this->do_get_plt_entry_size(); }
202 // Reserve a slot in the PLT for an existing symbol in an incremental update.
204 reserve_slot(unsigned int plt_index
)
206 this->free_list_
.remove((plt_index
+ 1) * this->get_plt_entry_size(),
207 (plt_index
+ 2) * this->get_plt_entry_size());
210 // Return the PLT address to use for a global symbol.
212 address_for_global(const Symbol
* sym
)
213 { return do_address_for_global(sym
); }
215 // Return the PLT address to use for a local symbol.
217 address_for_local(const Relobj
* obj
, unsigned int symndx
)
218 { return do_address_for_local(obj
, symndx
); }
220 // Add .eh_frame information for the PLT.
222 add_eh_frame(Layout
* layout
)
223 { this->do_add_eh_frame(layout
); }
226 Output_data_got
<64, false>*
228 { return this->got_
; }
230 Output_data_got_plt_x86_64
*
232 { return this->got_plt_
; }
235 got_irelative() const
236 { return this->got_irelative_
; }
238 // Fill in the first PLT entry.
240 fill_first_plt_entry(unsigned char* pov
,
241 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
242 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
243 { this->do_fill_first_plt_entry(pov
, got_address
, plt_address
); }
245 // Fill in a normal PLT entry. Returns the offset into the entry that
246 // should be the initial GOT slot value.
248 fill_plt_entry(unsigned char* pov
,
249 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
250 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
251 unsigned int got_offset
,
252 unsigned int plt_offset
,
253 unsigned int plt_index
)
255 return this->do_fill_plt_entry(pov
, got_address
, plt_address
,
256 got_offset
, plt_offset
, plt_index
);
259 // Fill in the reserved TLSDESC PLT entry.
261 fill_tlsdesc_entry(unsigned char* pov
,
262 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
263 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
264 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
265 unsigned int tlsdesc_got_offset
,
266 unsigned int plt_offset
)
268 this->do_fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
269 tlsdesc_got_offset
, plt_offset
);
273 do_get_plt_entry_size() const = 0;
276 do_fill_first_plt_entry(unsigned char* pov
,
277 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
278 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
)
282 do_fill_plt_entry(unsigned char* pov
,
283 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
284 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
285 unsigned int got_offset
,
286 unsigned int plt_offset
,
287 unsigned int plt_index
) = 0;
290 do_fill_tlsdesc_entry(unsigned char* pov
,
291 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
292 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
293 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
294 unsigned int tlsdesc_got_offset
,
295 unsigned int plt_offset
) = 0;
297 // Return the PLT address to use for a global symbol.
299 do_address_for_global(const Symbol
* sym
);
301 // Return the PLT address to use for a local symbol.
303 do_address_for_local(const Relobj
* obj
, unsigned int symndx
);
306 do_add_eh_frame(Layout
* layout
) = 0;
309 do_adjust_output_section(Output_section
* os
);
311 // Write to a map file.
313 do_print_to_mapfile(Mapfile
* mapfile
) const
314 { mapfile
->print_output_data(this, _("** PLT")); }
316 // The CIE of the .eh_frame unwind information for the PLT.
317 static const int plt_eh_frame_cie_size
= 16;
318 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
321 // Set the final size.
323 set_final_data_size();
325 // Write out the PLT data.
327 do_write(Output_file
*);
329 // The reloc section.
331 // The TLSDESC relocs, if necessary. These must follow the regular
333 Reloc_section
* tlsdesc_rel_
;
334 // The IRELATIVE relocs, if necessary. These must follow the
335 // regular PLT relocations and the TLSDESC relocations.
336 Reloc_section
* irelative_rel_
;
338 Output_data_got
<64, false>* got_
;
339 // The .got.plt section.
340 Output_data_got_plt_x86_64
* got_plt_
;
341 // The part of the .got.plt section used for IRELATIVE relocs.
342 Output_data_space
* got_irelative_
;
343 // The number of PLT entries.
345 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
346 // follow the regular PLT entries.
347 unsigned int irelative_count_
;
348 // Offset of the reserved TLSDESC_GOT entry when needed.
349 unsigned int tlsdesc_got_offset_
;
350 // List of available regions within the section, for incremental
352 Free_list free_list_
;
356 class Output_data_plt_x86_64_standard
: public Output_data_plt_x86_64
<size
>
359 Output_data_plt_x86_64_standard(Layout
* layout
,
360 Output_data_got
<64, false>* got
,
361 Output_data_got_plt_x86_64
* got_plt
,
362 Output_data_space
* got_irelative
)
363 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
364 got
, got_plt
, got_irelative
)
367 Output_data_plt_x86_64_standard(Layout
* layout
,
368 Output_data_got
<64, false>* got
,
369 Output_data_got_plt_x86_64
* got_plt
,
370 Output_data_space
* got_irelative
,
371 unsigned int plt_count
)
372 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
373 got
, got_plt
, got_irelative
,
379 do_get_plt_entry_size() const
380 { return plt_entry_size
; }
383 do_add_eh_frame(Layout
* layout
)
385 layout
->add_eh_frame_for_plt(this,
386 this->plt_eh_frame_cie
,
387 this->plt_eh_frame_cie_size
,
389 plt_eh_frame_fde_size
);
393 do_fill_first_plt_entry(unsigned char* pov
,
394 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
395 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
398 do_fill_plt_entry(unsigned char* pov
,
399 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
400 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
401 unsigned int got_offset
,
402 unsigned int plt_offset
,
403 unsigned int plt_index
);
406 do_fill_tlsdesc_entry(unsigned char* pov
,
407 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
408 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
409 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
410 unsigned int tlsdesc_got_offset
,
411 unsigned int plt_offset
);
414 // The size of an entry in the PLT.
415 static const int plt_entry_size
= 16;
417 // The first entry in the PLT.
418 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
419 // procedure linkage table for both programs and shared objects."
420 static const unsigned char first_plt_entry
[plt_entry_size
];
422 // Other entries in the PLT for an executable.
423 static const unsigned char plt_entry
[plt_entry_size
];
425 // The reserved TLSDESC entry in the PLT for an executable.
426 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
428 // The .eh_frame unwind information for the PLT.
429 static const int plt_eh_frame_fde_size
= 32;
430 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
433 class Output_data_plt_x86_64_bnd
: public Output_data_plt_x86_64
<64>
436 Output_data_plt_x86_64_bnd(Layout
* layout
,
437 Output_data_got
<64, false>* got
,
438 Output_data_got_plt_x86_64
* got_plt
,
439 Output_data_space
* got_irelative
)
440 : Output_data_plt_x86_64
<64>(layout
, plt_entry_size
,
441 got
, got_plt
, got_irelative
),
445 Output_data_plt_x86_64_bnd(Layout
* layout
,
446 Output_data_got
<64, false>* got
,
447 Output_data_got_plt_x86_64
* got_plt
,
448 Output_data_space
* got_irelative
,
449 unsigned int plt_count
)
450 : Output_data_plt_x86_64
<64>(layout
, plt_entry_size
,
451 got
, got_plt
, got_irelative
,
458 do_get_plt_entry_size() const
459 { return plt_entry_size
; }
461 // Return the PLT address to use for a global symbol.
463 do_address_for_global(const Symbol
*);
465 // Return the PLT address to use for a local symbol.
467 do_address_for_local(const Relobj
*, unsigned int symndx
);
470 do_add_eh_frame(Layout
* layout
)
472 layout
->add_eh_frame_for_plt(this,
473 this->plt_eh_frame_cie
,
474 this->plt_eh_frame_cie_size
,
476 plt_eh_frame_fde_size
);
480 do_fill_first_plt_entry(unsigned char* pov
,
481 elfcpp::Elf_types
<64>::Elf_Addr got_addr
,
482 elfcpp::Elf_types
<64>::Elf_Addr plt_addr
);
485 do_fill_plt_entry(unsigned char* pov
,
486 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
487 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
488 unsigned int got_offset
,
489 unsigned int plt_offset
,
490 unsigned int plt_index
);
493 do_fill_tlsdesc_entry(unsigned char* pov
,
494 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
495 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
496 elfcpp::Elf_types
<64>::Elf_Addr got_base
,
497 unsigned int tlsdesc_got_offset
,
498 unsigned int plt_offset
);
501 fill_aplt_entry(unsigned char* pov
,
502 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
503 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
504 unsigned int got_offset
,
505 unsigned int plt_offset
,
506 unsigned int plt_index
);
509 // Set the final size.
511 set_final_data_size();
513 // Write out the BND PLT data.
515 do_write(Output_file
*);
517 // Offset of the Additional PLT (if using -z bndplt).
518 unsigned int aplt_offset_
;
520 // The size of an entry in the PLT.
521 static const int plt_entry_size
= 16;
523 // The size of an entry in the additional PLT.
524 static const int aplt_entry_size
= 8;
526 // The first entry in the PLT.
527 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
528 // procedure linkage table for both programs and shared objects."
529 static const unsigned char first_plt_entry
[plt_entry_size
];
531 // Other entries in the PLT for an executable.
532 static const unsigned char plt_entry
[plt_entry_size
];
534 // Entries in the additional PLT.
535 static const unsigned char aplt_entry
[aplt_entry_size
];
537 // The reserved TLSDESC entry in the PLT for an executable.
538 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
540 // The .eh_frame unwind information for the PLT.
541 static const int plt_eh_frame_fde_size
= 32;
542 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
549 Lazy_view(Sized_relobj_file
<size
, false>* object
, unsigned int data_shndx
)
550 : object_(object
), data_shndx_(data_shndx
), view_(NULL
), view_size_(0)
554 operator[](size_t offset
)
556 if (this->view_
== NULL
)
557 this->view_
= this->object_
->section_contents(this->data_shndx_
,
560 if (offset
>= this->view_size_
)
562 return this->view_
[offset
];
566 Sized_relobj_file
<size
, false>* object_
;
567 unsigned int data_shndx_
;
568 const unsigned char* view_
;
569 section_size_type view_size_
;
572 // The x86_64 target class.
574 // http://www.x86-64.org/documentation/abi.pdf
575 // TLS info comes from
576 // http://people.redhat.com/drepper/tls.pdf
577 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
580 class Target_x86_64
: public Sized_target
<size
, false>
583 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
584 // uses only Elf64_Rela relocation entries with explicit addends."
585 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, size
, false> Reloc_section
;
587 Target_x86_64(const Target::Target_info
* info
= &x86_64_info
)
588 : Sized_target
<size
, false>(info
),
589 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
590 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rela_dyn_(NULL
),
591 rela_irelative_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
),
592 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
593 tls_base_symbol_defined_(false)
596 // Hook for a new output section.
598 do_new_output_section(Output_section
*) const;
600 // Scan the relocations to look for symbol adjustments.
602 gc_process_relocs(Symbol_table
* symtab
,
604 Sized_relobj_file
<size
, false>* object
,
605 unsigned int data_shndx
,
606 unsigned int sh_type
,
607 const unsigned char* prelocs
,
609 Output_section
* output_section
,
610 bool needs_special_offset_handling
,
611 size_t local_symbol_count
,
612 const unsigned char* plocal_symbols
);
614 // Scan the relocations to look for symbol adjustments.
616 scan_relocs(Symbol_table
* symtab
,
618 Sized_relobj_file
<size
, false>* object
,
619 unsigned int data_shndx
,
620 unsigned int sh_type
,
621 const unsigned char* prelocs
,
623 Output_section
* output_section
,
624 bool needs_special_offset_handling
,
625 size_t local_symbol_count
,
626 const unsigned char* plocal_symbols
);
628 // Finalize the sections.
630 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
632 // Return the value to use for a dynamic which requires special
635 do_dynsym_value(const Symbol
*) const;
637 // Relocate a section.
639 relocate_section(const Relocate_info
<size
, false>*,
640 unsigned int sh_type
,
641 const unsigned char* prelocs
,
643 Output_section
* output_section
,
644 bool needs_special_offset_handling
,
646 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
647 section_size_type view_size
,
648 const Reloc_symbol_changes
*);
650 // Scan the relocs during a relocatable link.
652 scan_relocatable_relocs(Symbol_table
* symtab
,
654 Sized_relobj_file
<size
, false>* object
,
655 unsigned int data_shndx
,
656 unsigned int sh_type
,
657 const unsigned char* prelocs
,
659 Output_section
* output_section
,
660 bool needs_special_offset_handling
,
661 size_t local_symbol_count
,
662 const unsigned char* plocal_symbols
,
663 Relocatable_relocs
*);
665 // Scan the relocs for --emit-relocs.
667 emit_relocs_scan(Symbol_table
* symtab
,
669 Sized_relobj_file
<size
, false>* object
,
670 unsigned int data_shndx
,
671 unsigned int sh_type
,
672 const unsigned char* prelocs
,
674 Output_section
* output_section
,
675 bool needs_special_offset_handling
,
676 size_t local_symbol_count
,
677 const unsigned char* plocal_syms
,
678 Relocatable_relocs
* rr
);
680 // Emit relocations for a section.
683 const Relocate_info
<size
, false>*,
684 unsigned int sh_type
,
685 const unsigned char* prelocs
,
687 Output_section
* output_section
,
688 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
690 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
691 section_size_type view_size
,
692 unsigned char* reloc_view
,
693 section_size_type reloc_view_size
);
695 // Return a string used to fill a code section with nops.
697 do_code_fill(section_size_type length
) const;
699 // Return whether SYM is defined by the ABI.
701 do_is_defined_by_abi(const Symbol
* sym
) const
702 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
704 // Return the symbol index to use for a target specific relocation.
705 // The only target specific relocation is R_X86_64_TLSDESC for a
706 // local symbol, which is an absolute reloc.
708 do_reloc_symbol_index(void*, unsigned int r_type
) const
710 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
714 // Return the addend to use for a target specific relocation.
716 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
718 // Return the PLT section.
720 do_plt_address_for_global(const Symbol
* gsym
) const
721 { return this->plt_section()->address_for_global(gsym
); }
724 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
725 { return this->plt_section()->address_for_local(relobj
, symndx
); }
727 // This function should be defined in targets that can use relocation
728 // types to determine (implemented in local_reloc_may_be_function_pointer
729 // and global_reloc_may_be_function_pointer)
730 // if a function's pointer is taken. ICF uses this in safe mode to only
731 // fold those functions whose pointer is defintely not taken. For x86_64
732 // pie binaries, safe ICF cannot be done by looking at only relocation
733 // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
734 // opcode is checked as well to distinguish a function call from taking
735 // a function's pointer.
737 do_can_check_for_function_pointers() const
740 // Return the base for a DW_EH_PE_datarel encoding.
742 do_ehframe_datarel_base() const;
744 // Adjust -fsplit-stack code which calls non-split-stack code.
746 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
747 section_offset_type fnoffset
, section_size_type fnsize
,
748 const unsigned char* prelocs
, size_t reloc_count
,
749 unsigned char* view
, section_size_type view_size
,
750 std::string
* from
, std::string
* to
) const;
752 // Return the size of the GOT section.
756 gold_assert(this->got_
!= NULL
);
757 return this->got_
->data_size();
760 // Return the number of entries in the GOT.
762 got_entry_count() const
764 if (this->got_
== NULL
)
766 return this->got_size() / 8;
769 // Return the number of entries in the PLT.
771 plt_entry_count() const;
773 // Return the offset of the first non-reserved PLT entry.
775 first_plt_entry_offset() const;
777 // Return the size of each PLT entry.
779 plt_entry_size() const;
781 // Return the size of each GOT entry.
783 got_entry_size() const
786 // Create the GOT section for an incremental update.
787 Output_data_got_base
*
788 init_got_plt_for_update(Symbol_table
* symtab
,
790 unsigned int got_count
,
791 unsigned int plt_count
);
793 // Reserve a GOT entry for a local symbol, and regenerate any
794 // necessary dynamic relocations.
796 reserve_local_got_entry(unsigned int got_index
,
797 Sized_relobj
<size
, false>* obj
,
799 unsigned int got_type
);
801 // Reserve a GOT entry for a global symbol, and regenerate any
802 // necessary dynamic relocations.
804 reserve_global_got_entry(unsigned int got_index
, Symbol
* gsym
,
805 unsigned int got_type
);
807 // Register an existing PLT entry for a global symbol.
809 register_global_plt_entry(Symbol_table
*, Layout
*, unsigned int plt_index
,
812 // Force a COPY relocation for a given symbol.
814 emit_copy_reloc(Symbol_table
*, Symbol
*, Output_section
*, off_t
);
816 // Apply an incremental relocation.
818 apply_relocation(const Relocate_info
<size
, false>* relinfo
,
819 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
821 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
824 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
825 section_size_type view_size
);
827 // Add a new reloc argument, returning the index in the vector.
829 add_tlsdesc_info(Sized_relobj_file
<size
, false>* object
, unsigned int r_sym
)
831 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
832 return this->tlsdesc_reloc_info_
.size() - 1;
835 Output_data_plt_x86_64
<size
>*
836 make_data_plt(Layout
* layout
,
837 Output_data_got
<64, false>* got
,
838 Output_data_got_plt_x86_64
* got_plt
,
839 Output_data_space
* got_irelative
)
841 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
);
844 Output_data_plt_x86_64
<size
>*
845 make_data_plt(Layout
* layout
,
846 Output_data_got
<64, false>* got
,
847 Output_data_got_plt_x86_64
* got_plt
,
848 Output_data_space
* got_irelative
,
849 unsigned int plt_count
)
851 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
,
855 virtual Output_data_plt_x86_64
<size
>*
856 do_make_data_plt(Layout
* layout
,
857 Output_data_got
<64, false>* got
,
858 Output_data_got_plt_x86_64
* got_plt
,
859 Output_data_space
* got_irelative
);
861 virtual Output_data_plt_x86_64
<size
>*
862 do_make_data_plt(Layout
* layout
,
863 Output_data_got
<64, false>* got
,
864 Output_data_got_plt_x86_64
* got_plt
,
865 Output_data_space
* got_irelative
,
866 unsigned int plt_count
);
869 // The class which scans relocations.
874 : issued_non_pic_error_(false)
878 get_reference_flags(unsigned int r_type
);
881 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
882 Sized_relobj_file
<size
, false>* object
,
883 unsigned int data_shndx
,
884 Output_section
* output_section
,
885 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
886 const elfcpp::Sym
<size
, false>& lsym
,
890 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
891 Sized_relobj_file
<size
, false>* object
,
892 unsigned int data_shndx
,
893 Output_section
* output_section
,
894 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
898 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
899 Target_x86_64
* target
,
900 Sized_relobj_file
<size
, false>* object
,
901 unsigned int data_shndx
,
902 Output_section
* output_section
,
903 const elfcpp::Rela
<size
, false>& reloc
,
905 const elfcpp::Sym
<size
, false>& lsym
);
908 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
909 Target_x86_64
* target
,
910 Sized_relobj_file
<size
, false>* object
,
911 unsigned int data_shndx
,
912 Output_section
* output_section
,
913 const elfcpp::Rela
<size
, false>& reloc
,
919 unsupported_reloc_local(Sized_relobj_file
<size
, false>*,
920 unsigned int r_type
);
923 unsupported_reloc_global(Sized_relobj_file
<size
, false>*,
924 unsigned int r_type
, Symbol
*);
927 check_non_pic(Relobj
*, unsigned int r_type
, Symbol
*);
930 possible_function_pointer_reloc(Sized_relobj_file
<size
, false>* src_obj
,
931 unsigned int src_indx
,
932 unsigned int r_offset
,
933 unsigned int r_type
);
936 reloc_needs_plt_for_ifunc(Sized_relobj_file
<size
, false>*,
937 unsigned int r_type
);
939 // Whether we have issued an error about a non-PIC compilation.
940 bool issued_non_pic_error_
;
943 // The class which implements relocation.
948 : skip_call_tls_get_addr_(false)
953 if (this->skip_call_tls_get_addr_
)
955 // FIXME: This needs to specify the location somehow.
956 gold_error(_("missing expected TLS relocation"));
960 // Do a relocation. Return false if the caller should not issue
961 // any warnings about this relocation.
963 relocate(const Relocate_info
<size
, false>*, unsigned int,
964 Target_x86_64
*, Output_section
*, size_t, const unsigned char*,
965 const Sized_symbol
<size
>*, const Symbol_value
<size
>*,
966 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
970 // Do a TLS relocation.
972 relocate_tls(const Relocate_info
<size
, false>*, Target_x86_64
*,
973 size_t relnum
, const elfcpp::Rela
<size
, false>&,
974 unsigned int r_type
, const Sized_symbol
<size
>*,
975 const Symbol_value
<size
>*,
976 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
979 // Do a TLS General-Dynamic to Initial-Exec transition.
981 tls_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
982 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
983 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
985 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
986 section_size_type view_size
);
988 // Do a TLS General-Dynamic to Local-Exec transition.
990 tls_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
991 Output_segment
* tls_segment
,
992 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
993 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
995 section_size_type view_size
);
997 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
999 tls_desc_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
1000 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1001 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1002 unsigned char* view
,
1003 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1004 section_size_type view_size
);
1006 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1008 tls_desc_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1009 Output_segment
* tls_segment
,
1010 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1011 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1012 unsigned char* view
,
1013 section_size_type view_size
);
1015 // Do a TLS Local-Dynamic to Local-Exec transition.
1017 tls_ld_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1018 Output_segment
* tls_segment
,
1019 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1020 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1021 unsigned char* view
,
1022 section_size_type view_size
);
1024 // Do a TLS Initial-Exec to Local-Exec transition.
1026 tls_ie_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1027 Output_segment
* tls_segment
,
1028 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1029 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1030 unsigned char* view
,
1031 section_size_type view_size
);
1033 // This is set if we should skip the next reloc, which should be a
1034 // PLT32 reloc against ___tls_get_addr.
1035 bool skip_call_tls_get_addr_
;
1038 // Check if relocation against this symbol is a candidate for
1040 // mov foo@GOTPCREL(%rip), %reg
1041 // to lea foo(%rip), %reg.
1042 template<class View_type
>
1044 can_convert_mov_to_lea(const Symbol
* gsym
, unsigned int r_type
,
1045 size_t r_offset
, View_type
* view
)
1047 gold_assert(gsym
!= NULL
);
1048 // We cannot do the conversion unless it's one of these relocations.
1049 if (r_type
!= elfcpp::R_X86_64_GOTPCREL
1050 && r_type
!= elfcpp::R_X86_64_GOTPCRELX
1051 && r_type
!= elfcpp::R_X86_64_REX_GOTPCRELX
)
1053 // We cannot convert references to IFUNC symbols, or to symbols that
1054 // are not local to the current module.
1055 // We can't do predefined symbols because they may become undefined
1056 // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1057 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1058 || gsym
->is_undefined()
1059 || gsym
->is_predefined()
1060 || gsym
->is_from_dynobj()
1061 || gsym
->is_preemptible())
1063 // If we are building a shared object and the symbol is protected, we may
1064 // need to go through the GOT.
1065 if (parameters
->options().shared()
1066 && gsym
->visibility() == elfcpp::STV_PROTECTED
)
1068 // We cannot convert references to the _DYNAMIC symbol.
1069 if (strcmp(gsym
->name(), "_DYNAMIC") == 0)
1071 // Check for a MOV opcode.
1072 return (*view
)[r_offset
- 2] == 0x8b;
1076 // callq *foo@GOTPCRELX(%rip) to
1078 // and jmpq *foo@GOTPCRELX(%rip) to
1081 template<class View_type
>
1083 can_convert_callq_to_direct(const Symbol
* gsym
, unsigned int r_type
,
1084 size_t r_offset
, View_type
* view
)
1086 gold_assert(gsym
!= NULL
);
1087 // We cannot do the conversion unless it's a GOTPCRELX relocation.
1088 if (r_type
!= elfcpp::R_X86_64_GOTPCRELX
)
1090 // We cannot convert references to IFUNC symbols, or to symbols that
1091 // are not local to the current module.
1092 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1093 || gsym
->is_undefined ()
1094 || gsym
->is_from_dynobj()
1095 || gsym
->is_preemptible())
1097 // Check for a CALLQ or JMPQ opcode.
1098 return ((*view
)[r_offset
- 2] == 0xff
1099 && ((*view
)[r_offset
- 1] == 0x15
1100 || (*view
)[r_offset
- 1] == 0x25));
1103 // Adjust TLS relocation type based on the options and whether this
1104 // is a local symbol.
1105 static tls::Tls_optimization
1106 optimize_tls_reloc(bool is_final
, int r_type
);
1108 // Get the GOT section, creating it if necessary.
1109 Output_data_got
<64, false>*
1110 got_section(Symbol_table
*, Layout
*);
1112 // Get the GOT PLT section.
1113 Output_data_got_plt_x86_64
*
1114 got_plt_section() const
1116 gold_assert(this->got_plt_
!= NULL
);
1117 return this->got_plt_
;
1120 // Get the GOT section for TLSDESC entries.
1121 Output_data_got
<64, false>*
1122 got_tlsdesc_section() const
1124 gold_assert(this->got_tlsdesc_
!= NULL
);
1125 return this->got_tlsdesc_
;
1128 // Create the PLT section.
1130 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
1132 // Create a PLT entry for a global symbol.
1134 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
1136 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1138 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
1139 Sized_relobj_file
<size
, false>* relobj
,
1140 unsigned int local_sym_index
);
1142 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1144 define_tls_base_symbol(Symbol_table
*, Layout
*);
1146 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1148 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
1150 // Create a GOT entry for the TLS module index.
1152 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1153 Sized_relobj_file
<size
, false>* object
);
1155 // Get the PLT section.
1156 Output_data_plt_x86_64
<size
>*
1159 gold_assert(this->plt_
!= NULL
);
1163 // Get the dynamic reloc section, creating it if necessary.
1165 rela_dyn_section(Layout
*);
1167 // Get the section to use for TLSDESC relocations.
1169 rela_tlsdesc_section(Layout
*) const;
1171 // Get the section to use for IRELATIVE relocations.
1173 rela_irelative_section(Layout
*);
1175 // Add a potential copy relocation.
1177 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
1178 Sized_relobj_file
<size
, false>* object
,
1179 unsigned int shndx
, Output_section
* output_section
,
1180 Symbol
* sym
, const elfcpp::Rela
<size
, false>& reloc
)
1182 unsigned int r_type
= elfcpp::elf_r_type
<size
>(reloc
.get_r_info());
1183 this->copy_relocs_
.copy_reloc(symtab
, layout
,
1184 symtab
->get_sized_symbol
<size
>(sym
),
1185 object
, shndx
, output_section
,
1186 r_type
, reloc
.get_r_offset(),
1187 reloc
.get_r_addend(),
1188 this->rela_dyn_section(layout
));
1191 // Information about this specific target which we pass to the
1192 // general Target structure.
1193 static const Target::Target_info x86_64_info
;
1195 // The types of GOT entries needed for this platform.
1196 // These values are exposed to the ABI in an incremental link.
1197 // Do not renumber existing values without changing the version
1198 // number of the .gnu_incremental_inputs section.
1201 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
1202 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
1203 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
1204 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
1207 // This type is used as the argument to the target specific
1208 // relocation routines. The only target specific reloc is
1209 // R_X86_64_TLSDESC against a local symbol.
1212 Tlsdesc_info(Sized_relobj_file
<size
, false>* a_object
, unsigned int a_r_sym
)
1213 : object(a_object
), r_sym(a_r_sym
)
1216 // The object in which the local symbol is defined.
1217 Sized_relobj_file
<size
, false>* object
;
1218 // The local symbol index in the object.
1223 Output_data_got
<64, false>* got_
;
1225 Output_data_plt_x86_64
<size
>* plt_
;
1226 // The GOT PLT section.
1227 Output_data_got_plt_x86_64
* got_plt_
;
1228 // The GOT section for IRELATIVE relocations.
1229 Output_data_space
* got_irelative_
;
1230 // The GOT section for TLSDESC relocations.
1231 Output_data_got
<64, false>* got_tlsdesc_
;
1232 // The _GLOBAL_OFFSET_TABLE_ symbol.
1233 Symbol
* global_offset_table_
;
1234 // The dynamic reloc section.
1235 Reloc_section
* rela_dyn_
;
1236 // The section to use for IRELATIVE relocs.
1237 Reloc_section
* rela_irelative_
;
1238 // Relocs saved to avoid a COPY reloc.
1239 Copy_relocs
<elfcpp::SHT_RELA
, size
, false> copy_relocs_
;
1240 // Offset of the GOT entry for the TLS module index.
1241 unsigned int got_mod_index_offset_
;
1242 // We handle R_X86_64_TLSDESC against a local symbol as a target
1243 // specific relocation. Here we store the object and local symbol
1244 // index for the relocation.
1245 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
1246 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1247 bool tls_base_symbol_defined_
;
1251 const Target::Target_info Target_x86_64
<64>::x86_64_info
=
1254 false, // is_big_endian
1255 elfcpp::EM_X86_64
, // machine_code
1256 false, // has_make_symbol
1257 false, // has_resolve
1258 true, // has_code_fill
1259 true, // is_default_stack_executable
1260 true, // can_icf_inline_merge_sections
1262 "/lib/ld64.so.1", // program interpreter
1263 0x400000, // default_text_segment_address
1264 0x1000, // abi_pagesize (overridable by -z max-page-size)
1265 0x1000, // common_pagesize (overridable by -z common-page-size)
1266 false, // isolate_execinstr
1268 elfcpp::SHN_UNDEF
, // small_common_shndx
1269 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1270 0, // small_common_section_flags
1271 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1272 NULL
, // attributes_section
1273 NULL
, // attributes_vendor
1274 "_start", // entry_symbol_name
1275 32, // hash_entry_size
1279 const Target::Target_info Target_x86_64
<32>::x86_64_info
=
1282 false, // is_big_endian
1283 elfcpp::EM_X86_64
, // machine_code
1284 false, // has_make_symbol
1285 false, // has_resolve
1286 true, // has_code_fill
1287 true, // is_default_stack_executable
1288 true, // can_icf_inline_merge_sections
1290 "/libx32/ldx32.so.1", // program interpreter
1291 0x400000, // default_text_segment_address
1292 0x1000, // abi_pagesize (overridable by -z max-page-size)
1293 0x1000, // common_pagesize (overridable by -z common-page-size)
1294 false, // isolate_execinstr
1296 elfcpp::SHN_UNDEF
, // small_common_shndx
1297 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1298 0, // small_common_section_flags
1299 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1300 NULL
, // attributes_section
1301 NULL
, // attributes_vendor
1302 "_start", // entry_symbol_name
1303 32, // hash_entry_size
1306 // This is called when a new output section is created. This is where
1307 // we handle the SHF_X86_64_LARGE.
1311 Target_x86_64
<size
>::do_new_output_section(Output_section
* os
) const
1313 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
1314 os
->set_is_large_section();
1317 // Get the GOT section, creating it if necessary.
1320 Output_data_got
<64, false>*
1321 Target_x86_64
<size
>::got_section(Symbol_table
* symtab
, Layout
* layout
)
1323 if (this->got_
== NULL
)
1325 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
1327 // When using -z now, we can treat .got.plt as a relro section.
1328 // Without -z now, it is modified after program startup by lazy
1330 bool is_got_plt_relro
= parameters
->options().now();
1331 Output_section_order got_order
= (is_got_plt_relro
1333 : ORDER_RELRO_LAST
);
1334 Output_section_order got_plt_order
= (is_got_plt_relro
1336 : ORDER_NON_RELRO_FIRST
);
1338 this->got_
= new Output_data_got
<64, false>();
1340 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1342 | elfcpp::SHF_WRITE
),
1343 this->got_
, got_order
, true);
1345 this->got_plt_
= new Output_data_got_plt_x86_64(layout
);
1346 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1348 | elfcpp::SHF_WRITE
),
1349 this->got_plt_
, got_plt_order
,
1352 // The first three entries are reserved.
1353 this->got_plt_
->set_current_data_size(3 * 8);
1355 if (!is_got_plt_relro
)
1357 // Those bytes can go into the relro segment.
1358 layout
->increase_relro(3 * 8);
1361 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1362 this->global_offset_table_
=
1363 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1364 Symbol_table::PREDEFINED
,
1366 0, 0, elfcpp::STT_OBJECT
,
1368 elfcpp::STV_HIDDEN
, 0,
1371 // If there are any IRELATIVE relocations, they get GOT entries
1372 // in .got.plt after the jump slot entries.
1373 this->got_irelative_
= new Output_data_space(8, "** GOT IRELATIVE PLT");
1374 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1376 | elfcpp::SHF_WRITE
),
1377 this->got_irelative_
,
1378 got_plt_order
, is_got_plt_relro
);
1380 // If there are any TLSDESC relocations, they get GOT entries in
1381 // .got.plt after the jump slot and IRELATIVE entries.
1382 this->got_tlsdesc_
= new Output_data_got
<64, false>();
1383 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1385 | elfcpp::SHF_WRITE
),
1387 got_plt_order
, is_got_plt_relro
);
1393 // Get the dynamic reloc section, creating it if necessary.
1396 typename Target_x86_64
<size
>::Reloc_section
*
1397 Target_x86_64
<size
>::rela_dyn_section(Layout
* layout
)
1399 if (this->rela_dyn_
== NULL
)
1401 gold_assert(layout
!= NULL
);
1402 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
1403 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1404 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
1405 ORDER_DYNAMIC_RELOCS
, false);
1407 return this->rela_dyn_
;
1410 // Get the section to use for IRELATIVE relocs, creating it if
1411 // necessary. These go in .rela.dyn, but only after all other dynamic
1412 // relocations. They need to follow the other dynamic relocations so
1413 // that they can refer to global variables initialized by those
1417 typename Target_x86_64
<size
>::Reloc_section
*
1418 Target_x86_64
<size
>::rela_irelative_section(Layout
* layout
)
1420 if (this->rela_irelative_
== NULL
)
1422 // Make sure we have already created the dynamic reloc section.
1423 this->rela_dyn_section(layout
);
1424 this->rela_irelative_
= new Reloc_section(false);
1425 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1426 elfcpp::SHF_ALLOC
, this->rela_irelative_
,
1427 ORDER_DYNAMIC_RELOCS
, false);
1428 gold_assert(this->rela_dyn_
->output_section()
1429 == this->rela_irelative_
->output_section());
1431 return this->rela_irelative_
;
1434 // Write the first three reserved words of the .got.plt section.
1435 // The remainder of the section is written while writing the PLT
1436 // in Output_data_plt_i386::do_write.
1439 Output_data_got_plt_x86_64::do_write(Output_file
* of
)
1441 // The first entry in the GOT is the address of the .dynamic section
1442 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1443 // We saved space for them when we created the section in
1444 // Target_x86_64::got_section.
1445 const off_t got_file_offset
= this->offset();
1446 gold_assert(this->data_size() >= 24);
1447 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 24);
1448 Output_section
* dynamic
= this->layout_
->dynamic_section();
1449 uint64_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1450 elfcpp::Swap
<64, false>::writeval(got_view
, dynamic_addr
);
1451 memset(got_view
+ 8, 0, 16);
1452 of
->write_output_view(got_file_offset
, 24, got_view
);
1455 // Initialize the PLT section.
1459 Output_data_plt_x86_64
<size
>::init(Layout
* layout
)
1461 this->rel_
= new Reloc_section(false);
1462 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1463 elfcpp::SHF_ALLOC
, this->rel_
,
1464 ORDER_DYNAMIC_PLT_RELOCS
, false);
1469 Output_data_plt_x86_64
<size
>::do_adjust_output_section(Output_section
* os
)
1471 os
->set_entsize(this->get_plt_entry_size());
1474 // Add an entry to the PLT.
1478 Output_data_plt_x86_64
<size
>::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1481 gold_assert(!gsym
->has_plt_offset());
1483 unsigned int plt_index
;
1485 section_offset_type got_offset
;
1487 unsigned int* pcount
;
1488 unsigned int offset
;
1489 unsigned int reserved
;
1490 Output_section_data_build
* got
;
1491 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1492 && gsym
->can_use_relative_reloc(false))
1494 pcount
= &this->irelative_count_
;
1497 got
= this->got_irelative_
;
1501 pcount
= &this->count_
;
1504 got
= this->got_plt_
;
1507 if (!this->is_data_size_valid())
1509 // Note that when setting the PLT offset for a non-IRELATIVE
1510 // entry we skip the initial reserved PLT entry.
1511 plt_index
= *pcount
+ offset
;
1512 plt_offset
= plt_index
* this->get_plt_entry_size();
1516 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1517 gold_assert(got_offset
== got
->current_data_size());
1519 // Every PLT entry needs a GOT entry which points back to the PLT
1520 // entry (this will be changed by the dynamic linker, normally
1521 // lazily when the function is called).
1522 got
->set_current_data_size(got_offset
+ 8);
1526 // FIXME: This is probably not correct for IRELATIVE relocs.
1528 // For incremental updates, find an available slot.
1529 plt_offset
= this->free_list_
.allocate(this->get_plt_entry_size(),
1530 this->get_plt_entry_size(), 0);
1531 if (plt_offset
== -1)
1532 gold_fallback(_("out of patch space (PLT);"
1533 " relink with --incremental-full"));
1535 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1536 // can be calculated from the PLT index, adjusting for the three
1537 // reserved entries at the beginning of the GOT.
1538 plt_index
= plt_offset
/ this->get_plt_entry_size() - 1;
1539 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1542 gsym
->set_plt_offset(plt_offset
);
1544 // Every PLT entry needs a reloc.
1545 this->add_relocation(symtab
, layout
, gsym
, got_offset
);
1547 // Note that we don't need to save the symbol. The contents of the
1548 // PLT are independent of which symbols are used. The symbols only
1549 // appear in the relocations.
1552 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1557 Output_data_plt_x86_64
<size
>::add_local_ifunc_entry(
1558 Symbol_table
* symtab
,
1560 Sized_relobj_file
<size
, false>* relobj
,
1561 unsigned int local_sym_index
)
1563 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1564 ++this->irelative_count_
;
1566 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1568 // Every PLT entry needs a GOT entry which points back to the PLT
1570 this->got_irelative_
->set_current_data_size(got_offset
+ 8);
1572 // Every PLT entry needs a reloc.
1573 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1574 rela
->add_symbolless_local_addend(relobj
, local_sym_index
,
1575 elfcpp::R_X86_64_IRELATIVE
,
1576 this->got_irelative_
, got_offset
, 0);
1581 // Add the relocation for a PLT entry.
1585 Output_data_plt_x86_64
<size
>::add_relocation(Symbol_table
* symtab
,
1588 unsigned int got_offset
)
1590 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1591 && gsym
->can_use_relative_reloc(false))
1593 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1594 rela
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
1595 this->got_irelative_
, got_offset
, 0);
1599 gsym
->set_needs_dynsym_entry();
1600 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
1605 // Return where the TLSDESC relocations should go, creating it if
1606 // necessary. These follow the JUMP_SLOT relocations.
1609 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1610 Output_data_plt_x86_64
<size
>::rela_tlsdesc(Layout
* layout
)
1612 if (this->tlsdesc_rel_
== NULL
)
1614 this->tlsdesc_rel_
= new Reloc_section(false);
1615 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1616 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
1617 ORDER_DYNAMIC_PLT_RELOCS
, false);
1618 gold_assert(this->tlsdesc_rel_
->output_section()
1619 == this->rel_
->output_section());
1621 return this->tlsdesc_rel_
;
1624 // Return where the IRELATIVE relocations should go in the PLT. These
1625 // follow the JUMP_SLOT and the TLSDESC relocations.
1628 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1629 Output_data_plt_x86_64
<size
>::rela_irelative(Symbol_table
* symtab
,
1632 if (this->irelative_rel_
== NULL
)
1634 // Make sure we have a place for the TLSDESC relocations, in
1635 // case we see any later on.
1636 this->rela_tlsdesc(layout
);
1637 this->irelative_rel_
= new Reloc_section(false);
1638 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1639 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1640 ORDER_DYNAMIC_PLT_RELOCS
, false);
1641 gold_assert(this->irelative_rel_
->output_section()
1642 == this->rel_
->output_section());
1644 if (parameters
->doing_static_link())
1646 // A statically linked executable will only have a .rela.plt
1647 // section to hold R_X86_64_IRELATIVE relocs for
1648 // STT_GNU_IFUNC symbols. The library will use these
1649 // symbols to locate the IRELATIVE relocs at program startup
1651 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
1652 Symbol_table::PREDEFINED
,
1653 this->irelative_rel_
, 0, 0,
1654 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1655 elfcpp::STV_HIDDEN
, 0, false, true);
1656 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
1657 Symbol_table::PREDEFINED
,
1658 this->irelative_rel_
, 0, 0,
1659 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1660 elfcpp::STV_HIDDEN
, 0, true, true);
1663 return this->irelative_rel_
;
1666 // Return the PLT address to use for a global symbol.
1670 Output_data_plt_x86_64
<size
>::do_address_for_global(const Symbol
* gsym
)
1672 uint64_t offset
= 0;
1673 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1674 && gsym
->can_use_relative_reloc(false))
1675 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1676 return this->address() + offset
+ gsym
->plt_offset();
1679 // Return the PLT address to use for a local symbol. These are always
1680 // IRELATIVE relocs.
1684 Output_data_plt_x86_64
<size
>::do_address_for_local(const Relobj
* object
,
1687 return (this->address()
1688 + (this->count_
+ 1) * this->get_plt_entry_size()
1689 + object
->local_plt_offset(r_sym
));
1692 // Set the final size.
1695 Output_data_plt_x86_64
<size
>::set_final_data_size()
1697 // Number of regular and IFUNC PLT entries, plus the first entry.
1698 unsigned int count
= this->count_
+ this->irelative_count_
+ 1;
1699 // Count the TLSDESC entry, if present.
1700 if (this->has_tlsdesc_entry())
1702 this->set_data_size(count
* this->get_plt_entry_size());
1705 // The first entry in the PLT for an executable.
1709 Output_data_plt_x86_64_standard
<size
>::first_plt_entry
[plt_entry_size
] =
1711 // From AMD64 ABI Draft 0.98, page 76
1712 0xff, 0x35, // pushq contents of memory address
1713 0, 0, 0, 0, // replaced with address of .got + 8
1714 0xff, 0x25, // jmp indirect
1715 0, 0, 0, 0, // replaced with address of .got + 16
1716 0x90, 0x90, 0x90, 0x90 // noop (x4)
1721 Output_data_plt_x86_64_standard
<size
>::do_fill_first_plt_entry(
1723 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1724 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
1726 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1727 // We do a jmp relative to the PC at the end of this instruction.
1728 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1730 - (plt_address
+ 6)));
1731 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
1733 - (plt_address
+ 12)));
1736 // Subsequent entries in the PLT for an executable.
1740 Output_data_plt_x86_64_standard
<size
>::plt_entry
[plt_entry_size
] =
1742 // From AMD64 ABI Draft 0.98, page 76
1743 0xff, 0x25, // jmpq indirect
1744 0, 0, 0, 0, // replaced with address of symbol in .got
1745 0x68, // pushq immediate
1746 0, 0, 0, 0, // replaced with offset into relocation table
1747 0xe9, // jmpq relative
1748 0, 0, 0, 0 // replaced with offset to start of .plt
1753 Output_data_plt_x86_64_standard
<size
>::do_fill_plt_entry(
1755 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1756 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
1757 unsigned int got_offset
,
1758 unsigned int plt_offset
,
1759 unsigned int plt_index
)
1761 // Check PC-relative offset overflow in PLT entry.
1762 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
1763 - (plt_address
+ plt_offset
+ 6));
1764 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
1765 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1768 memcpy(pov
, plt_entry
, plt_entry_size
);
1769 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1770 plt_got_pcrel_offset
);
1772 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
1773 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
1774 - (plt_offset
+ plt_entry_size
));
1779 // The reserved TLSDESC entry in the PLT for an executable.
1783 Output_data_plt_x86_64_standard
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
1785 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1786 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1787 0xff, 0x35, // pushq x(%rip)
1788 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1789 0xff, 0x25, // jmpq *y(%rip)
1790 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1797 Output_data_plt_x86_64_standard
<size
>::do_fill_tlsdesc_entry(
1799 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1800 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
1801 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
1802 unsigned int tlsdesc_got_offset
,
1803 unsigned int plt_offset
)
1805 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1806 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1808 - (plt_address
+ plt_offset
1810 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
1812 + tlsdesc_got_offset
1813 - (plt_address
+ plt_offset
1817 // Return the APLT address to use for a global symbol (for -z bndplt).
1820 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol
* gsym
)
1822 uint64_t offset
= this->aplt_offset_
;
1823 // Convert the PLT offset into an APLT offset.
1824 unsigned int plt_offset
= gsym
->plt_offset();
1825 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1826 && gsym
->can_use_relative_reloc(false))
1827 offset
+= this->regular_count() * aplt_entry_size
;
1829 plt_offset
-= plt_entry_size
;
1830 plt_offset
= plt_offset
/ (plt_entry_size
/ aplt_entry_size
);
1831 return this->address() + offset
+ plt_offset
;
1834 // Return the PLT address to use for a local symbol. These are always
1835 // IRELATIVE relocs.
1838 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj
* object
,
1841 // Convert the PLT offset into an APLT offset.
1842 unsigned int plt_offset
= ((object
->local_plt_offset(r_sym
) - plt_entry_size
)
1843 / (plt_entry_size
/ aplt_entry_size
));
1844 return (this->address()
1845 + this->aplt_offset_
1846 + this->regular_count() * aplt_entry_size
1850 // Set the final size.
1852 Output_data_plt_x86_64_bnd::set_final_data_size()
1854 // Number of regular and IFUNC PLT entries.
1855 unsigned int count
= this->entry_count();
1856 // Count the first entry and the TLSDESC entry, if present.
1857 unsigned int extra
= this->has_tlsdesc_entry() ? 2 : 1;
1858 unsigned int plt_size
= (count
+ extra
) * plt_entry_size
;
1859 // Offset of the APLT.
1860 this->aplt_offset_
= plt_size
;
1861 // Size of the APLT.
1862 plt_size
+= count
* aplt_entry_size
;
1863 this->set_data_size(plt_size
);
1866 // The first entry in the BND PLT.
1869 Output_data_plt_x86_64_bnd::first_plt_entry
[plt_entry_size
] =
1871 // From AMD64 ABI Draft 0.98, page 76
1872 0xff, 0x35, // pushq contents of memory address
1873 0, 0, 0, 0, // replaced with address of .got + 8
1874 0xf2, 0xff, 0x25, // bnd jmp indirect
1875 0, 0, 0, 0, // replaced with address of .got + 16
1876 0x0f, 0x1f, 0x00 // nop
1880 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
1882 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
1883 elfcpp::Elf_types
<64>::Elf_Addr plt_address
)
1885 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1886 // We do a jmp relative to the PC at the end of this instruction.
1887 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1889 - (plt_address
+ 6)));
1890 elfcpp::Swap
<32, false>::writeval(pov
+ 9,
1892 - (plt_address
+ 13)));
1895 // Subsequent entries in the BND PLT.
1898 Output_data_plt_x86_64_bnd::plt_entry
[plt_entry_size
] =
1900 // From AMD64 ABI Draft 0.99.8, page 139
1901 0x68, // pushq immediate
1902 0, 0, 0, 0, // replaced with offset into relocation table
1903 0xf2, 0xe9, // bnd jmpq relative
1904 0, 0, 0, 0, // replaced with offset to start of .plt
1905 0x0f, 0x1f, 0x44, 0, 0 // nop
1908 // Entries in the BND Additional PLT.
1911 Output_data_plt_x86_64_bnd::aplt_entry
[aplt_entry_size
] =
1913 // From AMD64 ABI Draft 0.99.8, page 139
1914 0xf2, 0xff, 0x25, // bnd jmpq indirect
1915 0, 0, 0, 0, // replaced with address of symbol in .got
1920 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
1922 elfcpp::Elf_types
<64>::Elf_Addr
,
1923 elfcpp::Elf_types
<64>::Elf_Addr
,
1925 unsigned int plt_offset
,
1926 unsigned int plt_index
)
1928 memcpy(pov
, plt_entry
, plt_entry_size
);
1929 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 1, plt_index
);
1930 elfcpp::Swap
<32, false>::writeval(pov
+ 7, -(plt_offset
+ 11));
1935 Output_data_plt_x86_64_bnd::fill_aplt_entry(
1937 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
1938 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
1939 unsigned int got_offset
,
1940 unsigned int plt_offset
,
1941 unsigned int plt_index
)
1943 // Check PC-relative offset overflow in PLT entry.
1944 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
1945 - (plt_address
+ plt_offset
+ 7));
1946 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
1947 gold_error(_("PC-relative offset overflow in APLT entry %d"),
1950 memcpy(pov
, aplt_entry
, aplt_entry_size
);
1951 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3, plt_got_pcrel_offset
);
1954 // The reserved TLSDESC entry in the PLT for an executable.
1957 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry
[plt_entry_size
] =
1959 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1960 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1961 0xff, 0x35, // pushq x(%rip)
1962 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1963 0xf2, 0xff, 0x25, // jmpq *y(%rip)
1964 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1965 0x0f, 0x1f, 0 // nop
1969 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
1971 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
1972 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
1973 elfcpp::Elf_types
<64>::Elf_Addr got_base
,
1974 unsigned int tlsdesc_got_offset
,
1975 unsigned int plt_offset
)
1977 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
1978 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1980 - (plt_address
+ plt_offset
1982 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
1984 + tlsdesc_got_offset
1985 - (plt_address
+ plt_offset
1989 // The .eh_frame unwind information for the PLT.
1993 Output_data_plt_x86_64
<size
>::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1996 'z', // Augmentation: augmentation size included.
1997 'R', // Augmentation: FDE encoding included.
1998 '\0', // End of augmentation string.
1999 1, // Code alignment factor.
2000 0x78, // Data alignment factor.
2001 16, // Return address column.
2002 1, // Augmentation size.
2003 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
2004 | elfcpp::DW_EH_PE_sdata4
),
2005 elfcpp::DW_CFA_def_cfa
, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
2006 elfcpp::DW_CFA_offset
+ 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2007 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
2013 Output_data_plt_x86_64_standard
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2015 0, 0, 0, 0, // Replaced with offset to .plt.
2016 0, 0, 0, 0, // Replaced with size of .plt.
2017 0, // Augmentation size.
2018 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2019 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2020 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2021 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2022 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2023 11, // Block length.
2024 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2025 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2026 elfcpp::DW_OP_lit15
, // Push 0xf.
2027 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2028 elfcpp::DW_OP_lit11
, // Push 0xb.
2029 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 0xb)
2030 elfcpp::DW_OP_lit3
, // Push 3.
2031 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 0xb) << 3)
2032 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2033 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2039 // The .eh_frame unwind information for the BND PLT.
2041 Output_data_plt_x86_64_bnd::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2043 0, 0, 0, 0, // Replaced with offset to .plt.
2044 0, 0, 0, 0, // Replaced with size of .plt.
2045 0, // Augmentation size.
2046 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2047 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2048 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2049 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2050 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2051 11, // Block length.
2052 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2053 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2054 elfcpp::DW_OP_lit15
, // Push 0xf.
2055 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2056 elfcpp::DW_OP_lit5
, // Push 5.
2057 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 5)
2058 elfcpp::DW_OP_lit3
, // Push 3.
2059 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 5) << 3)
2060 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
2061 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2067 // Write out the PLT. This uses the hand-coded instructions above,
2068 // and adjusts them as needed. This is specified by the AMD64 ABI.
2072 Output_data_plt_x86_64
<size
>::do_write(Output_file
* of
)
2074 const off_t offset
= this->offset();
2075 const section_size_type oview_size
=
2076 convert_to_section_size_type(this->data_size());
2077 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2079 const off_t got_file_offset
= this->got_plt_
->offset();
2080 gold_assert(parameters
->incremental_update()
2081 || (got_file_offset
+ this->got_plt_
->data_size()
2082 == this->got_irelative_
->offset()));
2083 const section_size_type got_size
=
2084 convert_to_section_size_type(this->got_plt_
->data_size()
2085 + this->got_irelative_
->data_size());
2086 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2089 unsigned char* pov
= oview
;
2091 // The base address of the .plt section.
2092 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
= this->address();
2093 // The base address of the .got section.
2094 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
= this->got_
->address();
2095 // The base address of the PLT portion of the .got section,
2096 // which is where the GOT pointer will point, and where the
2097 // three reserved GOT entries are located.
2098 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
2099 = this->got_plt_
->address();
2101 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2102 pov
+= this->get_plt_entry_size();
2104 // The first three entries in the GOT are reserved, and are written
2105 // by Output_data_got_plt_x86_64::do_write.
2106 unsigned char* got_pov
= got_view
+ 24;
2108 unsigned int plt_offset
= this->get_plt_entry_size();
2109 unsigned int got_offset
= 24;
2110 const unsigned int count
= this->count_
+ this->irelative_count_
;
2111 for (unsigned int plt_index
= 0;
2114 pov
+= this->get_plt_entry_size(),
2116 plt_offset
+= this->get_plt_entry_size(),
2119 // Set and adjust the PLT entry itself.
2120 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2121 got_address
, plt_address
,
2122 got_offset
, plt_offset
,
2125 // Set the entry in the GOT.
2126 elfcpp::Swap
<64, false>::writeval(got_pov
,
2127 plt_address
+ plt_offset
+ lazy_offset
);
2130 if (this->has_tlsdesc_entry())
2132 // Set and adjust the reserved TLSDESC PLT entry.
2133 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2134 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2135 tlsdesc_got_offset
, plt_offset
);
2136 pov
+= this->get_plt_entry_size();
2139 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2140 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2142 of
->write_output_view(offset
, oview_size
, oview
);
2143 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2146 // Write out the BND PLT.
2149 Output_data_plt_x86_64_bnd::do_write(Output_file
* of
)
2151 const off_t offset
= this->offset();
2152 const section_size_type oview_size
=
2153 convert_to_section_size_type(this->data_size());
2154 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2156 Output_data_got
<64, false>* got
= this->got();
2157 Output_data_got_plt_x86_64
* got_plt
= this->got_plt();
2158 Output_data_space
* got_irelative
= this->got_irelative();
2160 const off_t got_file_offset
= got_plt
->offset();
2161 gold_assert(parameters
->incremental_update()
2162 || (got_file_offset
+ got_plt
->data_size()
2163 == got_irelative
->offset()));
2164 const section_size_type got_size
=
2165 convert_to_section_size_type(got_plt
->data_size()
2166 + got_irelative
->data_size());
2167 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2170 unsigned char* pov
= oview
;
2172 // The base address of the .plt section.
2173 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
2174 // The base address of the .got section.
2175 elfcpp::Elf_types
<64>::Elf_Addr got_base
= got
->address();
2176 // The base address of the PLT portion of the .got section,
2177 // which is where the GOT pointer will point, and where the
2178 // three reserved GOT entries are located.
2179 elfcpp::Elf_types
<64>::Elf_Addr got_address
= got_plt
->address();
2181 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2182 pov
+= plt_entry_size
;
2184 // The first three entries in the GOT are reserved, and are written
2185 // by Output_data_got_plt_x86_64::do_write.
2186 unsigned char* got_pov
= got_view
+ 24;
2188 unsigned int plt_offset
= plt_entry_size
;
2189 unsigned int got_offset
= 24;
2190 const unsigned int count
= this->entry_count();
2191 for (unsigned int plt_index
= 0;
2194 pov
+= plt_entry_size
,
2196 plt_offset
+= plt_entry_size
,
2199 // Set and adjust the PLT entry itself.
2200 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2201 got_address
, plt_address
,
2202 got_offset
, plt_offset
,
2205 // Set the entry in the GOT.
2206 elfcpp::Swap
<64, false>::writeval(got_pov
,
2207 plt_address
+ plt_offset
+ lazy_offset
);
2210 if (this->has_tlsdesc_entry())
2212 // Set and adjust the reserved TLSDESC PLT entry.
2213 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2214 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2215 tlsdesc_got_offset
, plt_offset
);
2216 pov
+= this->get_plt_entry_size();
2219 // Write the additional PLT.
2221 for (unsigned int plt_index
= 0;
2224 pov
+= aplt_entry_size
,
2225 plt_offset
+= aplt_entry_size
,
2228 // Set and adjust the PLT entry itself.
2229 this->fill_aplt_entry(pov
, got_address
, plt_address
, got_offset
,
2230 plt_offset
, plt_index
);
2233 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2234 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2236 of
->write_output_view(offset
, oview_size
, oview
);
2237 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2240 // Create the PLT section.
2244 Target_x86_64
<size
>::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
2246 if (this->plt_
== NULL
)
2248 // Create the GOT sections first.
2249 this->got_section(symtab
, layout
);
2251 this->plt_
= this->make_data_plt(layout
, this->got_
, this->got_plt_
,
2252 this->got_irelative_
);
2254 // Add unwind information if requested.
2255 if (parameters
->options().ld_generated_unwind_info())
2256 this->plt_
->add_eh_frame(layout
);
2258 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
2260 | elfcpp::SHF_EXECINSTR
),
2261 this->plt_
, ORDER_PLT
, false);
2263 // Make the sh_info field of .rela.plt point to .plt.
2264 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
2265 rela_plt_os
->set_info_section(this->plt_
->output_section());
2270 Output_data_plt_x86_64
<32>*
2271 Target_x86_64
<32>::do_make_data_plt(Layout
* layout
,
2272 Output_data_got
<64, false>* got
,
2273 Output_data_got_plt_x86_64
* got_plt
,
2274 Output_data_space
* got_irelative
)
2276 return new Output_data_plt_x86_64_standard
<32>(layout
, got
, got_plt
,
2281 Output_data_plt_x86_64
<64>*
2282 Target_x86_64
<64>::do_make_data_plt(Layout
* layout
,
2283 Output_data_got
<64, false>* got
,
2284 Output_data_got_plt_x86_64
* got_plt
,
2285 Output_data_space
* got_irelative
)
2287 if (parameters
->options().bndplt())
2288 return new Output_data_plt_x86_64_bnd(layout
, got
, got_plt
,
2291 return new Output_data_plt_x86_64_standard
<64>(layout
, got
, got_plt
,
2296 Output_data_plt_x86_64
<32>*
2297 Target_x86_64
<32>::do_make_data_plt(Layout
* layout
,
2298 Output_data_got
<64, false>* got
,
2299 Output_data_got_plt_x86_64
* got_plt
,
2300 Output_data_space
* got_irelative
,
2301 unsigned int plt_count
)
2303 return new Output_data_plt_x86_64_standard
<32>(layout
, got
, got_plt
,
2309 Output_data_plt_x86_64
<64>*
2310 Target_x86_64
<64>::do_make_data_plt(Layout
* layout
,
2311 Output_data_got
<64, false>* got
,
2312 Output_data_got_plt_x86_64
* got_plt
,
2313 Output_data_space
* got_irelative
,
2314 unsigned int plt_count
)
2316 if (parameters
->options().bndplt())
2317 return new Output_data_plt_x86_64_bnd(layout
, got
, got_plt
,
2318 got_irelative
, plt_count
);
2320 return new Output_data_plt_x86_64_standard
<64>(layout
, got
, got_plt
,
2325 // Return the section for TLSDESC relocations.
2328 typename Target_x86_64
<size
>::Reloc_section
*
2329 Target_x86_64
<size
>::rela_tlsdesc_section(Layout
* layout
) const
2331 return this->plt_section()->rela_tlsdesc(layout
);
2334 // Create a PLT entry for a global symbol.
2338 Target_x86_64
<size
>::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
2341 if (gsym
->has_plt_offset())
2344 if (this->plt_
== NULL
)
2345 this->make_plt_section(symtab
, layout
);
2347 this->plt_
->add_entry(symtab
, layout
, gsym
);
2350 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
2354 Target_x86_64
<size
>::make_local_ifunc_plt_entry(
2355 Symbol_table
* symtab
, Layout
* layout
,
2356 Sized_relobj_file
<size
, false>* relobj
,
2357 unsigned int local_sym_index
)
2359 if (relobj
->local_has_plt_offset(local_sym_index
))
2361 if (this->plt_
== NULL
)
2362 this->make_plt_section(symtab
, layout
);
2363 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
2366 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
2369 // Return the number of entries in the PLT.
2373 Target_x86_64
<size
>::plt_entry_count() const
2375 if (this->plt_
== NULL
)
2377 return this->plt_
->entry_count();
2380 // Return the offset of the first non-reserved PLT entry.
2384 Target_x86_64
<size
>::first_plt_entry_offset() const
2386 if (this->plt_
== NULL
)
2388 return this->plt_
->first_plt_entry_offset();
2391 // Return the size of each PLT entry.
2395 Target_x86_64
<size
>::plt_entry_size() const
2397 if (this->plt_
== NULL
)
2399 return this->plt_
->get_plt_entry_size();
2402 // Create the GOT and PLT sections for an incremental update.
2405 Output_data_got_base
*
2406 Target_x86_64
<size
>::init_got_plt_for_update(Symbol_table
* symtab
,
2408 unsigned int got_count
,
2409 unsigned int plt_count
)
2411 gold_assert(this->got_
== NULL
);
2413 this->got_
= new Output_data_got
<64, false>(got_count
* 8);
2414 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
2416 | elfcpp::SHF_WRITE
),
2417 this->got_
, ORDER_RELRO_LAST
,
2420 // Add the three reserved entries.
2421 this->got_plt_
= new Output_data_got_plt_x86_64(layout
, (plt_count
+ 3) * 8);
2422 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
2424 | elfcpp::SHF_WRITE
),
2425 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
2428 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
2429 this->global_offset_table_
=
2430 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
2431 Symbol_table::PREDEFINED
,
2433 0, 0, elfcpp::STT_OBJECT
,
2435 elfcpp::STV_HIDDEN
, 0,
2438 // If there are any TLSDESC relocations, they get GOT entries in
2439 // .got.plt after the jump slot entries.
2440 // FIXME: Get the count for TLSDESC entries.
2441 this->got_tlsdesc_
= new Output_data_got
<64, false>(0);
2442 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
2443 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
2445 ORDER_NON_RELRO_FIRST
, false);
2447 // If there are any IRELATIVE relocations, they get GOT entries in
2448 // .got.plt after the jump slot and TLSDESC entries.
2449 this->got_irelative_
= new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
2450 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
2451 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
2452 this->got_irelative_
,
2453 ORDER_NON_RELRO_FIRST
, false);
2455 // Create the PLT section.
2456 this->plt_
= this->make_data_plt(layout
, this->got_
,
2458 this->got_irelative_
,
2461 // Add unwind information if requested.
2462 if (parameters
->options().ld_generated_unwind_info())
2463 this->plt_
->add_eh_frame(layout
);
2465 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
2466 elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
,
2467 this->plt_
, ORDER_PLT
, false);
2469 // Make the sh_info field of .rela.plt point to .plt.
2470 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
2471 rela_plt_os
->set_info_section(this->plt_
->output_section());
2473 // Create the rela_dyn section.
2474 this->rela_dyn_section(layout
);
2479 // Reserve a GOT entry for a local symbol, and regenerate any
2480 // necessary dynamic relocations.
2484 Target_x86_64
<size
>::reserve_local_got_entry(
2485 unsigned int got_index
,
2486 Sized_relobj
<size
, false>* obj
,
2488 unsigned int got_type
)
2490 unsigned int got_offset
= got_index
* 8;
2491 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
2493 this->got_
->reserve_local(got_index
, obj
, r_sym
, got_type
);
2496 case GOT_TYPE_STANDARD
:
2497 if (parameters
->options().output_is_position_independent())
2498 rela_dyn
->add_local_relative(obj
, r_sym
, elfcpp::R_X86_64_RELATIVE
,
2499 this->got_
, got_offset
, 0, false);
2501 case GOT_TYPE_TLS_OFFSET
:
2502 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_TPOFF64
,
2503 this->got_
, got_offset
, 0);
2505 case GOT_TYPE_TLS_PAIR
:
2506 this->got_
->reserve_slot(got_index
+ 1);
2507 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_DTPMOD64
,
2508 this->got_
, got_offset
, 0);
2510 case GOT_TYPE_TLS_DESC
:
2511 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
2512 // this->got_->reserve_slot(got_index + 1);
2513 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2514 // this->got_, got_offset, 0);
2521 // Reserve a GOT entry for a global symbol, and regenerate any
2522 // necessary dynamic relocations.
2526 Target_x86_64
<size
>::reserve_global_got_entry(unsigned int got_index
,
2528 unsigned int got_type
)
2530 unsigned int got_offset
= got_index
* 8;
2531 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
2533 this->got_
->reserve_global(got_index
, gsym
, got_type
);
2536 case GOT_TYPE_STANDARD
:
2537 if (!gsym
->final_value_is_known())
2539 if (gsym
->is_from_dynobj()
2540 || gsym
->is_undefined()
2541 || gsym
->is_preemptible()
2542 || gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2543 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
,
2544 this->got_
, got_offset
, 0);
2546 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
2547 this->got_
, got_offset
, 0, false);
2550 case GOT_TYPE_TLS_OFFSET
:
2551 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TPOFF64
,
2552 this->got_
, got_offset
, 0, false);
2554 case GOT_TYPE_TLS_PAIR
:
2555 this->got_
->reserve_slot(got_index
+ 1);
2556 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPMOD64
,
2557 this->got_
, got_offset
, 0, false);
2558 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPOFF64
,
2559 this->got_
, got_offset
+ 8, 0, false);
2561 case GOT_TYPE_TLS_DESC
:
2562 this->got_
->reserve_slot(got_index
+ 1);
2563 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TLSDESC
,
2564 this->got_
, got_offset
, 0, false);
2571 // Register an existing PLT entry for a global symbol.
2575 Target_x86_64
<size
>::register_global_plt_entry(Symbol_table
* symtab
,
2577 unsigned int plt_index
,
2580 gold_assert(this->plt_
!= NULL
);
2581 gold_assert(!gsym
->has_plt_offset());
2583 this->plt_
->reserve_slot(plt_index
);
2585 gsym
->set_plt_offset((plt_index
+ 1) * this->plt_entry_size());
2587 unsigned int got_offset
= (plt_index
+ 3) * 8;
2588 this->plt_
->add_relocation(symtab
, layout
, gsym
, got_offset
);
2591 // Force a COPY relocation for a given symbol.
2595 Target_x86_64
<size
>::emit_copy_reloc(
2596 Symbol_table
* symtab
, Symbol
* sym
, Output_section
* os
, off_t offset
)
2598 this->copy_relocs_
.emit_copy_reloc(symtab
,
2599 symtab
->get_sized_symbol
<size
>(sym
),
2602 this->rela_dyn_section(NULL
));
2605 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2609 Target_x86_64
<size
>::define_tls_base_symbol(Symbol_table
* symtab
,
2612 if (this->tls_base_symbol_defined_
)
2615 Output_segment
* tls_segment
= layout
->tls_segment();
2616 if (tls_segment
!= NULL
)
2618 bool is_exec
= parameters
->options().output_is_executable();
2619 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
2620 Symbol_table::PREDEFINED
,
2624 elfcpp::STV_HIDDEN
, 0,
2626 ? Symbol::SEGMENT_END
2627 : Symbol::SEGMENT_START
),
2630 this->tls_base_symbol_defined_
= true;
2633 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2637 Target_x86_64
<size
>::reserve_tlsdesc_entries(Symbol_table
* symtab
,
2640 if (this->plt_
== NULL
)
2641 this->make_plt_section(symtab
, layout
);
2643 if (!this->plt_
->has_tlsdesc_entry())
2645 // Allocate the TLSDESC_GOT entry.
2646 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
2647 unsigned int got_offset
= got
->add_constant(0);
2649 // Allocate the TLSDESC_PLT entry.
2650 this->plt_
->reserve_tlsdesc_entry(got_offset
);
2654 // Create a GOT entry for the TLS module index.
2658 Target_x86_64
<size
>::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
2659 Sized_relobj_file
<size
, false>* object
)
2661 if (this->got_mod_index_offset_
== -1U)
2663 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
2664 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
2665 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
2666 unsigned int got_offset
= got
->add_constant(0);
2667 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
2669 got
->add_constant(0);
2670 this->got_mod_index_offset_
= got_offset
;
2672 return this->got_mod_index_offset_
;
2675 // Optimize the TLS relocation type based on what we know about the
2676 // symbol. IS_FINAL is true if the final address of this symbol is
2677 // known at link time.
2680 tls::Tls_optimization
2681 Target_x86_64
<size
>::optimize_tls_reloc(bool is_final
, int r_type
)
2683 // If we are generating a shared library, then we can't do anything
2685 if (parameters
->options().shared())
2686 return tls::TLSOPT_NONE
;
2690 case elfcpp::R_X86_64_TLSGD
:
2691 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
2692 case elfcpp::R_X86_64_TLSDESC_CALL
:
2693 // These are General-Dynamic which permits fully general TLS
2694 // access. Since we know that we are generating an executable,
2695 // we can convert this to Initial-Exec. If we also know that
2696 // this is a local symbol, we can further switch to Local-Exec.
2698 return tls::TLSOPT_TO_LE
;
2699 return tls::TLSOPT_TO_IE
;
2701 case elfcpp::R_X86_64_TLSLD
:
2702 // This is Local-Dynamic, which refers to a local symbol in the
2703 // dynamic TLS block. Since we know that we generating an
2704 // executable, we can switch to Local-Exec.
2705 return tls::TLSOPT_TO_LE
;
2707 case elfcpp::R_X86_64_DTPOFF32
:
2708 case elfcpp::R_X86_64_DTPOFF64
:
2709 // Another Local-Dynamic reloc.
2710 return tls::TLSOPT_TO_LE
;
2712 case elfcpp::R_X86_64_GOTTPOFF
:
2713 // These are Initial-Exec relocs which get the thread offset
2714 // from the GOT. If we know that we are linking against the
2715 // local symbol, we can switch to Local-Exec, which links the
2716 // thread offset into the instruction.
2718 return tls::TLSOPT_TO_LE
;
2719 return tls::TLSOPT_NONE
;
2721 case elfcpp::R_X86_64_TPOFF32
:
2722 // When we already have Local-Exec, there is nothing further we
2724 return tls::TLSOPT_NONE
;
2731 // Get the Reference_flags for a particular relocation.
2735 Target_x86_64
<size
>::Scan::get_reference_flags(unsigned int r_type
)
2739 case elfcpp::R_X86_64_NONE
:
2740 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2741 case elfcpp::R_X86_64_GNU_VTENTRY
:
2742 case elfcpp::R_X86_64_GOTPC32
:
2743 case elfcpp::R_X86_64_GOTPC64
:
2744 // No symbol reference.
2747 case elfcpp::R_X86_64_64
:
2748 case elfcpp::R_X86_64_32
:
2749 case elfcpp::R_X86_64_32S
:
2750 case elfcpp::R_X86_64_16
:
2751 case elfcpp::R_X86_64_8
:
2752 return Symbol::ABSOLUTE_REF
;
2754 case elfcpp::R_X86_64_PC64
:
2755 case elfcpp::R_X86_64_PC32
:
2756 case elfcpp::R_X86_64_PC32_BND
:
2757 case elfcpp::R_X86_64_PC16
:
2758 case elfcpp::R_X86_64_PC8
:
2759 case elfcpp::R_X86_64_GOTOFF64
:
2760 return Symbol::RELATIVE_REF
;
2762 case elfcpp::R_X86_64_PLT32
:
2763 case elfcpp::R_X86_64_PLT32_BND
:
2764 case elfcpp::R_X86_64_PLTOFF64
:
2765 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
2767 case elfcpp::R_X86_64_GOT64
:
2768 case elfcpp::R_X86_64_GOT32
:
2769 case elfcpp::R_X86_64_GOTPCREL64
:
2770 case elfcpp::R_X86_64_GOTPCREL
:
2771 case elfcpp::R_X86_64_GOTPCRELX
:
2772 case elfcpp::R_X86_64_REX_GOTPCRELX
:
2773 case elfcpp::R_X86_64_GOTPLT64
:
2775 return Symbol::ABSOLUTE_REF
;
2777 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
2778 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
2779 case elfcpp::R_X86_64_TLSDESC_CALL
:
2780 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
2781 case elfcpp::R_X86_64_DTPOFF32
:
2782 case elfcpp::R_X86_64_DTPOFF64
:
2783 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
2784 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
2785 return Symbol::TLS_REF
;
2787 case elfcpp::R_X86_64_COPY
:
2788 case elfcpp::R_X86_64_GLOB_DAT
:
2789 case elfcpp::R_X86_64_JUMP_SLOT
:
2790 case elfcpp::R_X86_64_RELATIVE
:
2791 case elfcpp::R_X86_64_IRELATIVE
:
2792 case elfcpp::R_X86_64_TPOFF64
:
2793 case elfcpp::R_X86_64_DTPMOD64
:
2794 case elfcpp::R_X86_64_TLSDESC
:
2795 case elfcpp::R_X86_64_SIZE32
:
2796 case elfcpp::R_X86_64_SIZE64
:
2798 // Not expected. We will give an error later.
2803 // Report an unsupported relocation against a local symbol.
2807 Target_x86_64
<size
>::Scan::unsupported_reloc_local(
2808 Sized_relobj_file
<size
, false>* object
,
2809 unsigned int r_type
)
2811 gold_error(_("%s: unsupported reloc %u against local symbol"),
2812 object
->name().c_str(), r_type
);
2815 // We are about to emit a dynamic relocation of type R_TYPE. If the
2816 // dynamic linker does not support it, issue an error. The GNU linker
2817 // only issues a non-PIC error for an allocated read-only section.
2818 // Here we know the section is allocated, but we don't know that it is
2819 // read-only. But we check for all the relocation types which the
2820 // glibc dynamic linker supports, so it seems appropriate to issue an
2821 // error even if the section is not read-only. If GSYM is not NULL,
2822 // it is the symbol the relocation is against; if it is NULL, the
2823 // relocation is against a local symbol.
2827 Target_x86_64
<size
>::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
,
2832 // These are the relocation types supported by glibc for x86_64
2833 // which should always work.
2834 case elfcpp::R_X86_64_RELATIVE
:
2835 case elfcpp::R_X86_64_IRELATIVE
:
2836 case elfcpp::R_X86_64_GLOB_DAT
:
2837 case elfcpp::R_X86_64_JUMP_SLOT
:
2838 case elfcpp::R_X86_64_DTPMOD64
:
2839 case elfcpp::R_X86_64_DTPOFF64
:
2840 case elfcpp::R_X86_64_TPOFF64
:
2841 case elfcpp::R_X86_64_64
:
2842 case elfcpp::R_X86_64_COPY
:
2845 // glibc supports these reloc types, but they can overflow.
2846 case elfcpp::R_X86_64_PC32
:
2847 case elfcpp::R_X86_64_PC32_BND
:
2848 // A PC relative reference is OK against a local symbol or if
2849 // the symbol is defined locally.
2851 || (!gsym
->is_from_dynobj()
2852 && !gsym
->is_undefined()
2853 && !gsym
->is_preemptible()))
2856 case elfcpp::R_X86_64_32
:
2857 // R_X86_64_32 is OK for x32.
2858 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
2860 if (this->issued_non_pic_error_
)
2862 gold_assert(parameters
->options().output_is_position_independent());
2864 object
->error(_("requires dynamic R_X86_64_32 reloc which may "
2865 "overflow at runtime; recompile with -fPIC"));
2871 case elfcpp::R_X86_64_32
:
2872 r_name
= "R_X86_64_32";
2874 case elfcpp::R_X86_64_PC32
:
2875 r_name
= "R_X86_64_PC32";
2877 case elfcpp::R_X86_64_PC32_BND
:
2878 r_name
= "R_X86_64_PC32_BND";
2884 object
->error(_("requires dynamic %s reloc against '%s' "
2885 "which may overflow at runtime; recompile "
2887 r_name
, gsym
->name());
2889 this->issued_non_pic_error_
= true;
2893 // This prevents us from issuing more than one error per reloc
2894 // section. But we can still wind up issuing more than one
2895 // error per object file.
2896 if (this->issued_non_pic_error_
)
2898 gold_assert(parameters
->options().output_is_position_independent());
2899 object
->error(_("requires unsupported dynamic reloc %u; "
2900 "recompile with -fPIC"),
2902 this->issued_non_pic_error_
= true;
2905 case elfcpp::R_X86_64_NONE
:
2910 // Return whether we need to make a PLT entry for a relocation of the
2911 // given type against a STT_GNU_IFUNC symbol.
2915 Target_x86_64
<size
>::Scan::reloc_needs_plt_for_ifunc(
2916 Sized_relobj_file
<size
, false>* object
,
2917 unsigned int r_type
)
2919 int flags
= Scan::get_reference_flags(r_type
);
2920 if (flags
& Symbol::TLS_REF
)
2921 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2922 object
->name().c_str(), r_type
);
2926 // Scan a relocation for a local symbol.
2930 Target_x86_64
<size
>::Scan::local(Symbol_table
* symtab
,
2932 Target_x86_64
<size
>* target
,
2933 Sized_relobj_file
<size
, false>* object
,
2934 unsigned int data_shndx
,
2935 Output_section
* output_section
,
2936 const elfcpp::Rela
<size
, false>& reloc
,
2937 unsigned int r_type
,
2938 const elfcpp::Sym
<size
, false>& lsym
,
2944 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2945 bool is_ifunc
= lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
;
2946 if (is_ifunc
&& this->reloc_needs_plt_for_ifunc(object
, r_type
))
2948 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2949 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
2954 case elfcpp::R_X86_64_NONE
:
2955 case elfcpp::R_X86_64_GNU_VTINHERIT
:
2956 case elfcpp::R_X86_64_GNU_VTENTRY
:
2959 case elfcpp::R_X86_64_64
:
2960 // If building a shared library (or a position-independent
2961 // executable), we need to create a dynamic relocation for this
2962 // location. The relocation applied at link time will apply the
2963 // link-time value, so we flag the location with an
2964 // R_X86_64_RELATIVE relocation so the dynamic loader can
2965 // relocate it easily.
2966 if (parameters
->options().output_is_position_independent())
2968 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2969 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2970 rela_dyn
->add_local_relative(object
, r_sym
,
2972 ? elfcpp::R_X86_64_RELATIVE64
2973 : elfcpp::R_X86_64_RELATIVE
),
2974 output_section
, data_shndx
,
2975 reloc
.get_r_offset(),
2976 reloc
.get_r_addend(), is_ifunc
);
2980 case elfcpp::R_X86_64_32
:
2981 case elfcpp::R_X86_64_32S
:
2982 case elfcpp::R_X86_64_16
:
2983 case elfcpp::R_X86_64_8
:
2984 // If building a shared library (or a position-independent
2985 // executable), we need to create a dynamic relocation for this
2986 // location. We can't use an R_X86_64_RELATIVE relocation
2987 // because that is always a 64-bit relocation.
2988 if (parameters
->options().output_is_position_independent())
2990 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2991 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
2993 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
2994 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
2995 rela_dyn
->add_local_relative(object
, r_sym
,
2996 elfcpp::R_X86_64_RELATIVE
,
2997 output_section
, data_shndx
,
2998 reloc
.get_r_offset(),
2999 reloc
.get_r_addend(), is_ifunc
);
3003 this->check_non_pic(object
, r_type
, NULL
);
3005 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3006 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3007 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
3008 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
3009 data_shndx
, reloc
.get_r_offset(),
3010 reloc
.get_r_addend());
3013 gold_assert(lsym
.get_st_value() == 0);
3014 unsigned int shndx
= lsym
.get_st_shndx();
3016 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
3019 object
->error(_("section symbol %u has bad shndx %u"),
3022 rela_dyn
->add_local_section(object
, shndx
,
3023 r_type
, output_section
,
3024 data_shndx
, reloc
.get_r_offset(),
3025 reloc
.get_r_addend());
3030 case elfcpp::R_X86_64_PC64
:
3031 case elfcpp::R_X86_64_PC32
:
3032 case elfcpp::R_X86_64_PC32_BND
:
3033 case elfcpp::R_X86_64_PC16
:
3034 case elfcpp::R_X86_64_PC8
:
3037 case elfcpp::R_X86_64_PLT32
:
3038 case elfcpp::R_X86_64_PLT32_BND
:
3039 // Since we know this is a local symbol, we can handle this as a
3043 case elfcpp::R_X86_64_GOTPC32
:
3044 case elfcpp::R_X86_64_GOTOFF64
:
3045 case elfcpp::R_X86_64_GOTPC64
:
3046 case elfcpp::R_X86_64_PLTOFF64
:
3047 // We need a GOT section.
3048 target
->got_section(symtab
, layout
);
3049 // For PLTOFF64, we'd normally want a PLT section, but since we
3050 // know this is a local symbol, no PLT is needed.
3053 case elfcpp::R_X86_64_GOT64
:
3054 case elfcpp::R_X86_64_GOT32
:
3055 case elfcpp::R_X86_64_GOTPCREL64
:
3056 case elfcpp::R_X86_64_GOTPCREL
:
3057 case elfcpp::R_X86_64_GOTPCRELX
:
3058 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3059 case elfcpp::R_X86_64_GOTPLT64
:
3061 // The symbol requires a GOT section.
3062 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
3064 // If the relocation symbol isn't IFUNC,
3065 // and is local, then we will convert
3066 // mov foo@GOTPCREL(%rip), %reg
3067 // to lea foo(%rip), %reg.
3068 // in Relocate::relocate.
3069 if ((r_type
== elfcpp::R_X86_64_GOTPCREL
3070 || r_type
== elfcpp::R_X86_64_GOTPCRELX
3071 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
3072 && reloc
.get_r_offset() >= 2
3075 section_size_type stype
;
3076 const unsigned char* view
= object
->section_contents(data_shndx
,
3078 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
3083 // The symbol requires a GOT entry.
3084 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3086 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
3087 // lets function pointers compare correctly with shared
3088 // libraries. Otherwise we would need an IRELATIVE reloc.
3091 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
3093 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
3096 // If we are generating a shared object, we need to add a
3097 // dynamic relocation for this symbol's GOT entry.
3098 if (parameters
->options().output_is_position_independent())
3100 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3101 // R_X86_64_RELATIVE assumes a 64-bit relocation.
3102 if (r_type
!= elfcpp::R_X86_64_GOT32
)
3104 unsigned int got_offset
=
3105 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
3106 rela_dyn
->add_local_relative(object
, r_sym
,
3107 elfcpp::R_X86_64_RELATIVE
,
3108 got
, got_offset
, 0, is_ifunc
);
3112 this->check_non_pic(object
, r_type
, NULL
);
3114 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
3115 rela_dyn
->add_local(
3116 object
, r_sym
, r_type
, got
,
3117 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
3121 // For GOTPLT64, we'd normally want a PLT section, but since
3122 // we know this is a local symbol, no PLT is needed.
3126 case elfcpp::R_X86_64_COPY
:
3127 case elfcpp::R_X86_64_GLOB_DAT
:
3128 case elfcpp::R_X86_64_JUMP_SLOT
:
3129 case elfcpp::R_X86_64_RELATIVE
:
3130 case elfcpp::R_X86_64_IRELATIVE
:
3131 // These are outstanding tls relocs, which are unexpected when linking
3132 case elfcpp::R_X86_64_TPOFF64
:
3133 case elfcpp::R_X86_64_DTPMOD64
:
3134 case elfcpp::R_X86_64_TLSDESC
:
3135 gold_error(_("%s: unexpected reloc %u in object file"),
3136 object
->name().c_str(), r_type
);
3139 // These are initial tls relocs, which are expected when linking
3140 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3141 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3142 case elfcpp::R_X86_64_TLSDESC_CALL
:
3143 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3144 case elfcpp::R_X86_64_DTPOFF32
:
3145 case elfcpp::R_X86_64_DTPOFF64
:
3146 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3147 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3149 bool output_is_shared
= parameters
->options().shared();
3150 const tls::Tls_optimization optimized_type
3151 = Target_x86_64
<size
>::optimize_tls_reloc(!output_is_shared
,
3155 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
3156 if (optimized_type
== tls::TLSOPT_NONE
)
3158 // Create a pair of GOT entries for the module index and
3159 // dtv-relative offset.
3160 Output_data_got
<64, false>* got
3161 = target
->got_section(symtab
, layout
);
3162 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3163 unsigned int shndx
= lsym
.get_st_shndx();
3165 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
3167 object
->error(_("local symbol %u has bad shndx %u"),
3170 got
->add_local_pair_with_rel(object
, r_sym
,
3173 target
->rela_dyn_section(layout
),
3174 elfcpp::R_X86_64_DTPMOD64
);
3176 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3177 unsupported_reloc_local(object
, r_type
);
3180 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3181 target
->define_tls_base_symbol(symtab
, layout
);
3182 if (optimized_type
== tls::TLSOPT_NONE
)
3184 // Create reserved PLT and GOT entries for the resolver.
3185 target
->reserve_tlsdesc_entries(symtab
, layout
);
3187 // Generate a double GOT entry with an
3188 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
3189 // is resolved lazily, so the GOT entry needs to be in
3190 // an area in .got.plt, not .got. Call got_section to
3191 // make sure the section has been created.
3192 target
->got_section(symtab
, layout
);
3193 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
3194 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3195 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
3197 unsigned int got_offset
= got
->add_constant(0);
3198 got
->add_constant(0);
3199 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
3201 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
3202 // We store the arguments we need in a vector, and
3203 // use the index into the vector as the parameter
3204 // to pass to the target specific routines.
3205 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
3206 void* arg
= reinterpret_cast<void*>(intarg
);
3207 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
3208 got
, got_offset
, 0);
3211 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3212 unsupported_reloc_local(object
, r_type
);
3215 case elfcpp::R_X86_64_TLSDESC_CALL
:
3218 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3219 if (optimized_type
== tls::TLSOPT_NONE
)
3221 // Create a GOT entry for the module index.
3222 target
->got_mod_index_entry(symtab
, layout
, object
);
3224 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3225 unsupported_reloc_local(object
, r_type
);
3228 case elfcpp::R_X86_64_DTPOFF32
:
3229 case elfcpp::R_X86_64_DTPOFF64
:
3232 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3233 layout
->set_has_static_tls();
3234 if (optimized_type
== tls::TLSOPT_NONE
)
3236 // Create a GOT entry for the tp-relative offset.
3237 Output_data_got
<64, false>* got
3238 = target
->got_section(symtab
, layout
);
3239 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3240 got
->add_local_with_rel(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
3241 target
->rela_dyn_section(layout
),
3242 elfcpp::R_X86_64_TPOFF64
);
3244 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3245 unsupported_reloc_local(object
, r_type
);
3248 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3249 layout
->set_has_static_tls();
3250 if (output_is_shared
)
3251 unsupported_reloc_local(object
, r_type
);
3260 case elfcpp::R_X86_64_SIZE32
:
3261 case elfcpp::R_X86_64_SIZE64
:
3263 gold_error(_("%s: unsupported reloc %u against local symbol"),
3264 object
->name().c_str(), r_type
);
3270 // Report an unsupported relocation against a global symbol.
3274 Target_x86_64
<size
>::Scan::unsupported_reloc_global(
3275 Sized_relobj_file
<size
, false>* object
,
3276 unsigned int r_type
,
3279 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3280 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
3283 // Returns true if this relocation type could be that of a function pointer.
3286 Target_x86_64
<size
>::Scan::possible_function_pointer_reloc(
3287 Sized_relobj_file
<size
, false>* src_obj
,
3288 unsigned int src_indx
,
3289 unsigned int r_offset
,
3290 unsigned int r_type
)
3294 case elfcpp::R_X86_64_64
:
3295 case elfcpp::R_X86_64_32
:
3296 case elfcpp::R_X86_64_32S
:
3297 case elfcpp::R_X86_64_16
:
3298 case elfcpp::R_X86_64_8
:
3299 case elfcpp::R_X86_64_GOT64
:
3300 case elfcpp::R_X86_64_GOT32
:
3301 case elfcpp::R_X86_64_GOTPCREL64
:
3302 case elfcpp::R_X86_64_GOTPCREL
:
3303 case elfcpp::R_X86_64_GOTPCRELX
:
3304 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3305 case elfcpp::R_X86_64_GOTPLT64
:
3309 case elfcpp::R_X86_64_PC32
:
3311 // This relocation may be used both for function calls and
3312 // for taking address of a function. We distinguish between
3313 // them by checking the opcodes.
3314 uint64_t sh_flags
= src_obj
->section_flags(src_indx
);
3315 bool is_executable
= (sh_flags
& elfcpp::SHF_EXECINSTR
) != 0;
3318 section_size_type stype
;
3319 const unsigned char* view
= src_obj
->section_contents(src_indx
,
3325 && view
[r_offset
- 1] == 0xe8)
3330 && view
[r_offset
- 1] == 0xe9)
3333 // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3335 && view
[r_offset
- 2] == 0x0f
3336 && view
[r_offset
- 1] >= 0x80
3337 && view
[r_offset
- 1] <= 0x8f)
3341 // Be conservative and treat all others as function pointers.
3348 // For safe ICF, scan a relocation for a local symbol to check if it
3349 // corresponds to a function pointer being taken. In that case mark
3350 // the function whose pointer was taken as not foldable.
3354 Target_x86_64
<size
>::Scan::local_reloc_may_be_function_pointer(
3357 Target_x86_64
<size
>* ,
3358 Sized_relobj_file
<size
, false>* src_obj
,
3359 unsigned int src_indx
,
3361 const elfcpp::Rela
<size
, false>& reloc
,
3362 unsigned int r_type
,
3363 const elfcpp::Sym
<size
, false>&)
3365 // When building a shared library, do not fold any local symbols as it is
3366 // not possible to distinguish pointer taken versus a call by looking at
3367 // the relocation types.
3368 if (parameters
->options().shared())
3371 return possible_function_pointer_reloc(src_obj
, src_indx
,
3372 reloc
.get_r_offset(), r_type
);
3375 // For safe ICF, scan a relocation for a global symbol to check if it
3376 // corresponds to a function pointer being taken. In that case mark
3377 // the function whose pointer was taken as not foldable.
3381 Target_x86_64
<size
>::Scan::global_reloc_may_be_function_pointer(
3384 Target_x86_64
<size
>* ,
3385 Sized_relobj_file
<size
, false>* src_obj
,
3386 unsigned int src_indx
,
3388 const elfcpp::Rela
<size
, false>& reloc
,
3389 unsigned int r_type
,
3392 // When building a shared library, do not fold symbols whose visibility
3393 // is hidden, internal or protected.
3394 if (parameters
->options().shared()
3395 && (gsym
->visibility() == elfcpp::STV_INTERNAL
3396 || gsym
->visibility() == elfcpp::STV_PROTECTED
3397 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
3400 return possible_function_pointer_reloc(src_obj
, src_indx
,
3401 reloc
.get_r_offset(), r_type
);
3404 // Scan a relocation for a global symbol.
3408 Target_x86_64
<size
>::Scan::global(Symbol_table
* symtab
,
3410 Target_x86_64
<size
>* target
,
3411 Sized_relobj_file
<size
, false>* object
,
3412 unsigned int data_shndx
,
3413 Output_section
* output_section
,
3414 const elfcpp::Rela
<size
, false>& reloc
,
3415 unsigned int r_type
,
3418 // A STT_GNU_IFUNC symbol may require a PLT entry.
3419 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
3420 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
3421 target
->make_plt_entry(symtab
, layout
, gsym
);
3425 case elfcpp::R_X86_64_NONE
:
3426 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3427 case elfcpp::R_X86_64_GNU_VTENTRY
:
3430 case elfcpp::R_X86_64_64
:
3431 case elfcpp::R_X86_64_32
:
3432 case elfcpp::R_X86_64_32S
:
3433 case elfcpp::R_X86_64_16
:
3434 case elfcpp::R_X86_64_8
:
3436 // Make a PLT entry if necessary.
3437 if (gsym
->needs_plt_entry())
3439 target
->make_plt_entry(symtab
, layout
, gsym
);
3440 // Since this is not a PC-relative relocation, we may be
3441 // taking the address of a function. In that case we need to
3442 // set the entry in the dynamic symbol table to the address of
3444 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
3445 gsym
->set_needs_dynsym_value();
3447 // Make a dynamic relocation if necessary.
3448 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
3450 if (!parameters
->options().output_is_position_independent()
3451 && gsym
->may_need_copy_reloc())
3453 target
->copy_reloc(symtab
, layout
, object
,
3454 data_shndx
, output_section
, gsym
, reloc
);
3456 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
3457 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
3458 && gsym
->type() == elfcpp::STT_GNU_IFUNC
3459 && gsym
->can_use_relative_reloc(false)
3460 && !gsym
->is_from_dynobj()
3461 && !gsym
->is_undefined()
3462 && !gsym
->is_preemptible())
3464 // Use an IRELATIVE reloc for a locally defined
3465 // STT_GNU_IFUNC symbol. This makes a function
3466 // address in a PIE executable match the address in a
3467 // shared library that it links against.
3468 Reloc_section
* rela_dyn
=
3469 target
->rela_irelative_section(layout
);
3470 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
3471 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
3472 output_section
, object
,
3474 reloc
.get_r_offset(),
3475 reloc
.get_r_addend());
3477 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
3478 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
3479 && gsym
->can_use_relative_reloc(false))
3481 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3482 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
3483 output_section
, object
,
3485 reloc
.get_r_offset(),
3486 reloc
.get_r_addend(), false);
3490 this->check_non_pic(object
, r_type
, gsym
);
3491 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3492 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
3493 data_shndx
, reloc
.get_r_offset(),
3494 reloc
.get_r_addend());
3500 case elfcpp::R_X86_64_PC64
:
3501 case elfcpp::R_X86_64_PC32
:
3502 case elfcpp::R_X86_64_PC32_BND
:
3503 case elfcpp::R_X86_64_PC16
:
3504 case elfcpp::R_X86_64_PC8
:
3506 // Make a PLT entry if necessary.
3507 if (gsym
->needs_plt_entry())
3508 target
->make_plt_entry(symtab
, layout
, gsym
);
3509 // Make a dynamic relocation if necessary.
3510 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
3512 if (parameters
->options().output_is_executable()
3513 && gsym
->may_need_copy_reloc())
3515 target
->copy_reloc(symtab
, layout
, object
,
3516 data_shndx
, output_section
, gsym
, reloc
);
3520 this->check_non_pic(object
, r_type
, gsym
);
3521 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3522 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
3523 data_shndx
, reloc
.get_r_offset(),
3524 reloc
.get_r_addend());
3530 case elfcpp::R_X86_64_GOT64
:
3531 case elfcpp::R_X86_64_GOT32
:
3532 case elfcpp::R_X86_64_GOTPCREL64
:
3533 case elfcpp::R_X86_64_GOTPCREL
:
3534 case elfcpp::R_X86_64_GOTPCRELX
:
3535 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3536 case elfcpp::R_X86_64_GOTPLT64
:
3538 // The symbol requires a GOT entry.
3539 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
3541 // If we convert this from
3542 // mov foo@GOTPCREL(%rip), %reg
3543 // to lea foo(%rip), %reg.
3546 // (callq|jmpq) *foo@GOTPCRELX(%rip) to
3548 // in Relocate::relocate, then there is nothing to do here.
3550 Lazy_view
<size
> view(object
, data_shndx
);
3551 size_t r_offset
= reloc
.get_r_offset();
3553 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
, r_type
,
3558 && Target_x86_64
<size
>::can_convert_callq_to_direct(gsym
, r_type
,
3563 if (gsym
->final_value_is_known())
3565 // For a STT_GNU_IFUNC symbol we want the PLT address.
3566 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
3567 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
3569 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
3573 // If this symbol is not fully resolved, we need to add a
3574 // dynamic relocation for it.
3575 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3577 // Use a GLOB_DAT rather than a RELATIVE reloc if:
3579 // 1) The symbol may be defined in some other module.
3581 // 2) We are building a shared library and this is a
3582 // protected symbol; using GLOB_DAT means that the dynamic
3583 // linker can use the address of the PLT in the main
3584 // executable when appropriate so that function address
3585 // comparisons work.
3587 // 3) This is a STT_GNU_IFUNC symbol in position dependent
3588 // code, again so that function address comparisons work.
3589 if (gsym
->is_from_dynobj()
3590 || gsym
->is_undefined()
3591 || gsym
->is_preemptible()
3592 || (gsym
->visibility() == elfcpp::STV_PROTECTED
3593 && parameters
->options().shared())
3594 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
3595 && parameters
->options().output_is_position_independent()))
3596 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
3597 elfcpp::R_X86_64_GLOB_DAT
);
3600 // For a STT_GNU_IFUNC symbol we want to write the PLT
3601 // offset into the GOT, so that function pointer
3602 // comparisons work correctly.
3604 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
3605 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
3608 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
3609 // Tell the dynamic linker to use the PLT address
3610 // when resolving relocations.
3611 if (gsym
->is_from_dynobj()
3612 && !parameters
->options().shared())
3613 gsym
->set_needs_dynsym_value();
3617 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
3618 rela_dyn
->add_global_relative(gsym
,
3619 elfcpp::R_X86_64_RELATIVE
,
3620 got
, got_off
, 0, false);
3627 case elfcpp::R_X86_64_PLT32
:
3628 case elfcpp::R_X86_64_PLT32_BND
:
3629 // If the symbol is fully resolved, this is just a PC32 reloc.
3630 // Otherwise we need a PLT entry.
3631 if (gsym
->final_value_is_known())
3633 // If building a shared library, we can also skip the PLT entry
3634 // if the symbol is defined in the output file and is protected
3636 if (gsym
->is_defined()
3637 && !gsym
->is_from_dynobj()
3638 && !gsym
->is_preemptible())
3640 target
->make_plt_entry(symtab
, layout
, gsym
);
3643 case elfcpp::R_X86_64_GOTPC32
:
3644 case elfcpp::R_X86_64_GOTOFF64
:
3645 case elfcpp::R_X86_64_GOTPC64
:
3646 case elfcpp::R_X86_64_PLTOFF64
:
3647 // We need a GOT section.
3648 target
->got_section(symtab
, layout
);
3649 // For PLTOFF64, we also need a PLT entry (but only if the
3650 // symbol is not fully resolved).
3651 if (r_type
== elfcpp::R_X86_64_PLTOFF64
3652 && !gsym
->final_value_is_known())
3653 target
->make_plt_entry(symtab
, layout
, gsym
);
3656 case elfcpp::R_X86_64_COPY
:
3657 case elfcpp::R_X86_64_GLOB_DAT
:
3658 case elfcpp::R_X86_64_JUMP_SLOT
:
3659 case elfcpp::R_X86_64_RELATIVE
:
3660 case elfcpp::R_X86_64_IRELATIVE
:
3661 // These are outstanding tls relocs, which are unexpected when linking
3662 case elfcpp::R_X86_64_TPOFF64
:
3663 case elfcpp::R_X86_64_DTPMOD64
:
3664 case elfcpp::R_X86_64_TLSDESC
:
3665 gold_error(_("%s: unexpected reloc %u in object file"),
3666 object
->name().c_str(), r_type
);
3669 // These are initial tls relocs, which are expected for global()
3670 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3671 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3672 case elfcpp::R_X86_64_TLSDESC_CALL
:
3673 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3674 case elfcpp::R_X86_64_DTPOFF32
:
3675 case elfcpp::R_X86_64_DTPOFF64
:
3676 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3677 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3679 // For the Initial-Exec model, we can treat undef symbols as final
3680 // when building an executable.
3681 const bool is_final
= (gsym
->final_value_is_known() ||
3682 (r_type
== elfcpp::R_X86_64_GOTTPOFF
&&
3683 gsym
->is_undefined() &&
3684 parameters
->options().output_is_executable()));
3685 const tls::Tls_optimization optimized_type
3686 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
3689 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
3690 if (optimized_type
== tls::TLSOPT_NONE
)
3692 // Create a pair of GOT entries for the module index and
3693 // dtv-relative offset.
3694 Output_data_got
<64, false>* got
3695 = target
->got_section(symtab
, layout
);
3696 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
3697 target
->rela_dyn_section(layout
),
3698 elfcpp::R_X86_64_DTPMOD64
,
3699 elfcpp::R_X86_64_DTPOFF64
);
3701 else if (optimized_type
== tls::TLSOPT_TO_IE
)
3703 // Create a GOT entry for the tp-relative offset.
3704 Output_data_got
<64, false>* got
3705 = target
->got_section(symtab
, layout
);
3706 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3707 target
->rela_dyn_section(layout
),
3708 elfcpp::R_X86_64_TPOFF64
);
3710 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3711 unsupported_reloc_global(object
, r_type
, gsym
);
3714 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3715 target
->define_tls_base_symbol(symtab
, layout
);
3716 if (optimized_type
== tls::TLSOPT_NONE
)
3718 // Create reserved PLT and GOT entries for the resolver.
3719 target
->reserve_tlsdesc_entries(symtab
, layout
);
3721 // Create a double GOT entry with an R_X86_64_TLSDESC
3722 // reloc. The R_X86_64_TLSDESC reloc is resolved
3723 // lazily, so the GOT entry needs to be in an area in
3724 // .got.plt, not .got. Call got_section to make sure
3725 // the section has been created.
3726 target
->got_section(symtab
, layout
);
3727 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
3728 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
3729 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
3730 elfcpp::R_X86_64_TLSDESC
, 0);
3732 else if (optimized_type
== tls::TLSOPT_TO_IE
)
3734 // Create a GOT entry for the tp-relative offset.
3735 Output_data_got
<64, false>* got
3736 = target
->got_section(symtab
, layout
);
3737 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3738 target
->rela_dyn_section(layout
),
3739 elfcpp::R_X86_64_TPOFF64
);
3741 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3742 unsupported_reloc_global(object
, r_type
, gsym
);
3745 case elfcpp::R_X86_64_TLSDESC_CALL
:
3748 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3749 if (optimized_type
== tls::TLSOPT_NONE
)
3751 // Create a GOT entry for the module index.
3752 target
->got_mod_index_entry(symtab
, layout
, object
);
3754 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3755 unsupported_reloc_global(object
, r_type
, gsym
);
3758 case elfcpp::R_X86_64_DTPOFF32
:
3759 case elfcpp::R_X86_64_DTPOFF64
:
3762 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3763 layout
->set_has_static_tls();
3764 if (optimized_type
== tls::TLSOPT_NONE
)
3766 // Create a GOT entry for the tp-relative offset.
3767 Output_data_got
<64, false>* got
3768 = target
->got_section(symtab
, layout
);
3769 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
3770 target
->rela_dyn_section(layout
),
3771 elfcpp::R_X86_64_TPOFF64
);
3773 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3774 unsupported_reloc_global(object
, r_type
, gsym
);
3777 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3778 layout
->set_has_static_tls();
3779 if (parameters
->options().shared())
3780 unsupported_reloc_global(object
, r_type
, gsym
);
3789 case elfcpp::R_X86_64_SIZE32
:
3790 case elfcpp::R_X86_64_SIZE64
:
3792 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3793 object
->name().c_str(), r_type
,
3794 gsym
->demangled_name().c_str());
3801 Target_x86_64
<size
>::gc_process_relocs(Symbol_table
* symtab
,
3803 Sized_relobj_file
<size
, false>* object
,
3804 unsigned int data_shndx
,
3805 unsigned int sh_type
,
3806 const unsigned char* prelocs
,
3808 Output_section
* output_section
,
3809 bool needs_special_offset_handling
,
3810 size_t local_symbol_count
,
3811 const unsigned char* plocal_symbols
)
3813 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
3816 if (sh_type
== elfcpp::SHT_REL
)
3821 gold::gc_process_relocs
<size
, false, Target_x86_64
<size
>, Scan
,
3831 needs_special_offset_handling
,
3836 // Scan relocations for a section.
3840 Target_x86_64
<size
>::scan_relocs(Symbol_table
* symtab
,
3842 Sized_relobj_file
<size
, false>* object
,
3843 unsigned int data_shndx
,
3844 unsigned int sh_type
,
3845 const unsigned char* prelocs
,
3847 Output_section
* output_section
,
3848 bool needs_special_offset_handling
,
3849 size_t local_symbol_count
,
3850 const unsigned char* plocal_symbols
)
3852 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
3855 if (sh_type
== elfcpp::SHT_REL
)
3857 gold_error(_("%s: unsupported REL reloc section"),
3858 object
->name().c_str());
3862 gold::scan_relocs
<size
, false, Target_x86_64
<size
>, Scan
, Classify_reloc
>(
3871 needs_special_offset_handling
,
3876 // Finalize the sections.
3880 Target_x86_64
<size
>::do_finalize_sections(
3882 const Input_objects
*,
3883 Symbol_table
* symtab
)
3885 const Reloc_section
* rel_plt
= (this->plt_
== NULL
3887 : this->plt_
->rela_plt());
3888 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
3889 this->rela_dyn_
, true, false);
3891 // Fill in some more dynamic tags.
3892 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
3895 if (this->plt_
!= NULL
3896 && this->plt_
->output_section() != NULL
3897 && this->plt_
->has_tlsdesc_entry())
3899 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
3900 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
3901 this->got_
->finalize_data_size();
3902 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
3903 this->plt_
, plt_offset
);
3904 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
3905 this->got_
, got_offset
);
3909 // Emit any relocs we saved in an attempt to avoid generating COPY
3911 if (this->copy_relocs_
.any_saved_relocs())
3912 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
3914 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3915 // the .got.plt section.
3916 Symbol
* sym
= this->global_offset_table_
;
3919 uint64_t data_size
= this->got_plt_
->current_data_size();
3920 symtab
->get_sized_symbol
<size
>(sym
)->set_symsize(data_size
);
3923 if (parameters
->doing_static_link()
3924 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
3926 // If linking statically, make sure that the __rela_iplt symbols
3927 // were defined if necessary, even if we didn't create a PLT.
3928 static const Define_symbol_in_segment syms
[] =
3931 "__rela_iplt_start", // name
3932 elfcpp::PT_LOAD
, // segment_type
3933 elfcpp::PF_W
, // segment_flags_set
3934 elfcpp::PF(0), // segment_flags_clear
3937 elfcpp::STT_NOTYPE
, // type
3938 elfcpp::STB_GLOBAL
, // binding
3939 elfcpp::STV_HIDDEN
, // visibility
3941 Symbol::SEGMENT_START
, // offset_from_base
3945 "__rela_iplt_end", // name
3946 elfcpp::PT_LOAD
, // segment_type
3947 elfcpp::PF_W
, // segment_flags_set
3948 elfcpp::PF(0), // segment_flags_clear
3951 elfcpp::STT_NOTYPE
, // type
3952 elfcpp::STB_GLOBAL
, // binding
3953 elfcpp::STV_HIDDEN
, // visibility
3955 Symbol::SEGMENT_START
, // offset_from_base
3960 symtab
->define_symbols(layout
, 2, syms
,
3961 layout
->script_options()->saw_sections_clause());
3965 // For x32, we need to handle PC-relative relocations using full 64-bit
3966 // arithmetic, so that we can detect relocation overflows properly.
3967 // This class overrides the pcrela32_check methods from the defaults in
3968 // Relocate_functions in reloc.h.
3971 class X86_64_relocate_functions
: public Relocate_functions
<size
, false>
3974 typedef Relocate_functions
<size
, false> Base
;
3976 // Do a simple PC relative relocation with the addend in the
3978 static inline typename
Base::Reloc_status
3979 pcrela32_check(unsigned char* view
,
3980 typename
elfcpp::Elf_types
<64>::Elf_Addr value
,
3981 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
3982 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
3984 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
3985 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
3986 value
= value
+ addend
- address
;
3987 elfcpp::Swap
<32, false>::writeval(wv
, value
);
3988 return (Bits
<32>::has_overflow(value
)
3989 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
3992 // Do a simple PC relative relocation with a Symbol_value with the
3993 // addend in the relocation.
3994 static inline typename
Base::Reloc_status
3995 pcrela32_check(unsigned char* view
,
3996 const Sized_relobj_file
<size
, false>* object
,
3997 const Symbol_value
<size
>* psymval
,
3998 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
3999 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
4001 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
4002 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
4003 typename
elfcpp::Elf_types
<64>::Elf_Addr value
;
4005 value
= psymval
->value(object
, addend
);
4008 // For negative addends, get the symbol value without
4009 // the addend, then add the addend using 64-bit arithmetic.
4010 value
= psymval
->value(object
, 0);
4014 elfcpp::Swap
<32, false>::writeval(wv
, value
);
4015 return (Bits
<32>::has_overflow(value
)
4016 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
4020 // Perform a relocation.
4024 Target_x86_64
<size
>::Relocate::relocate(
4025 const Relocate_info
<size
, false>* relinfo
,
4027 Target_x86_64
<size
>* target
,
4030 const unsigned char* preloc
,
4031 const Sized_symbol
<size
>* gsym
,
4032 const Symbol_value
<size
>* psymval
,
4033 unsigned char* view
,
4034 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4035 section_size_type view_size
)
4037 typedef X86_64_relocate_functions
<size
> Reloc_funcs
;
4038 const elfcpp::Rela
<size
, false> rela(preloc
);
4039 unsigned int r_type
= elfcpp::elf_r_type
<size
>(rela
.get_r_info());
4041 if (this->skip_call_tls_get_addr_
)
4043 if ((r_type
!= elfcpp::R_X86_64_PLT32
4044 && r_type
!= elfcpp::R_X86_64_GOTPCREL
4045 && r_type
!= elfcpp::R_X86_64_GOTPCRELX
4046 && r_type
!= elfcpp::R_X86_64_PLT32_BND
4047 && r_type
!= elfcpp::R_X86_64_PC32_BND
4048 && r_type
!= elfcpp::R_X86_64_PC32
)
4050 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
4052 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4053 _("missing expected TLS relocation"));
4054 this->skip_call_tls_get_addr_
= false;
4058 this->skip_call_tls_get_addr_
= false;
4066 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
4068 // Pick the value to use for symbols defined in the PLT.
4069 Symbol_value
<size
> symval
;
4071 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
4073 symval
.set_output_value(target
->plt_address_for_global(gsym
));
4076 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
4078 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4079 if (object
->local_has_plt_offset(r_sym
))
4081 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
4086 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4088 // Get the GOT offset if needed.
4089 // The GOT pointer points to the end of the GOT section.
4090 // We need to subtract the size of the GOT section to get
4091 // the actual offset to use in the relocation.
4092 bool have_got_offset
= false;
4093 // Since the actual offset is always negative, we use signed int to
4094 // support 64-bit GOT relocations.
4098 case elfcpp::R_X86_64_GOT32
:
4099 case elfcpp::R_X86_64_GOT64
:
4100 case elfcpp::R_X86_64_GOTPLT64
:
4101 case elfcpp::R_X86_64_GOTPCREL64
:
4104 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
4105 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
4109 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4110 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
4111 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
4112 - target
->got_size());
4114 have_got_offset
= true;
4121 typename
Reloc_funcs::Reloc_status rstatus
= Reloc_funcs::RELOC_OK
;
4125 case elfcpp::R_X86_64_NONE
:
4126 case elfcpp::R_X86_64_GNU_VTINHERIT
:
4127 case elfcpp::R_X86_64_GNU_VTENTRY
:
4130 case elfcpp::R_X86_64_64
:
4131 Reloc_funcs::rela64(view
, object
, psymval
, addend
);
4134 case elfcpp::R_X86_64_PC64
:
4135 Reloc_funcs::pcrela64(view
, object
, psymval
, addend
,
4139 case elfcpp::R_X86_64_32
:
4140 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
4141 Reloc_funcs::CHECK_UNSIGNED
);
4144 case elfcpp::R_X86_64_32S
:
4145 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
4146 Reloc_funcs::CHECK_SIGNED
);
4149 case elfcpp::R_X86_64_PC32
:
4150 case elfcpp::R_X86_64_PC32_BND
:
4151 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
4155 case elfcpp::R_X86_64_16
:
4156 Reloc_funcs::rela16(view
, object
, psymval
, addend
);
4159 case elfcpp::R_X86_64_PC16
:
4160 Reloc_funcs::pcrela16(view
, object
, psymval
, addend
, address
);
4163 case elfcpp::R_X86_64_8
:
4164 Reloc_funcs::rela8(view
, object
, psymval
, addend
);
4167 case elfcpp::R_X86_64_PC8
:
4168 Reloc_funcs::pcrela8(view
, object
, psymval
, addend
, address
);
4171 case elfcpp::R_X86_64_PLT32
:
4172 case elfcpp::R_X86_64_PLT32_BND
:
4173 gold_assert(gsym
== NULL
4174 || gsym
->has_plt_offset()
4175 || gsym
->final_value_is_known()
4176 || (gsym
->is_defined()
4177 && !gsym
->is_from_dynobj()
4178 && !gsym
->is_preemptible()));
4179 // Note: while this code looks the same as for R_X86_64_PC32, it
4180 // behaves differently because psymval was set to point to
4181 // the PLT entry, rather than the symbol, in Scan::global().
4182 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
4186 case elfcpp::R_X86_64_PLTOFF64
:
4189 gold_assert(gsym
->has_plt_offset()
4190 || gsym
->final_value_is_known());
4191 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
;
4192 // This is the address of GLOBAL_OFFSET_TABLE.
4193 got_address
= target
->got_plt_section()->address();
4194 Reloc_funcs::rela64(view
, object
, psymval
, addend
- got_address
);
4198 case elfcpp::R_X86_64_GOT32
:
4199 gold_assert(have_got_offset
);
4200 Reloc_funcs::rela32(view
, got_offset
, addend
);
4203 case elfcpp::R_X86_64_GOTPC32
:
4206 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4207 value
= target
->got_plt_section()->address();
4208 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
4212 case elfcpp::R_X86_64_GOT64
:
4213 case elfcpp::R_X86_64_GOTPLT64
:
4214 // R_X86_64_GOTPLT64 is obsolete and treated the same as
4216 gold_assert(have_got_offset
);
4217 Reloc_funcs::rela64(view
, got_offset
, addend
);
4220 case elfcpp::R_X86_64_GOTPC64
:
4223 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4224 value
= target
->got_plt_section()->address();
4225 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
4229 case elfcpp::R_X86_64_GOTOFF64
:
4231 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4232 value
= (psymval
->value(object
, 0)
4233 - target
->got_plt_section()->address());
4234 Reloc_funcs::rela64(view
, value
, addend
);
4238 case elfcpp::R_X86_64_GOTPCREL
:
4239 case elfcpp::R_X86_64_GOTPCRELX
:
4240 case elfcpp::R_X86_64_REX_GOTPCRELX
:
4243 // mov foo@GOTPCREL(%rip), %reg
4244 // to lea foo(%rip), %reg.
4247 && rela
.get_r_offset() >= 2
4249 && !psymval
->is_ifunc_symbol())
4251 && rela
.get_r_offset() >= 2
4252 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
, r_type
,
4256 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
4259 // callq *foo@GOTPCRELX(%rip) to
4261 // and jmpq *foo@GOTPCRELX(%rip) to
4264 else if (gsym
!= NULL
4265 && rela
.get_r_offset() >= 2
4266 && Target_x86_64
<size
>::can_convert_callq_to_direct(gsym
,
4270 if (view
[-1] == 0x15)
4272 // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4273 // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
4276 // Convert GOTPCRELX to 32-bit pc relative reloc.
4277 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
4281 // Convert jmpq *foo@GOTPCRELX(%rip) to
4284 // The opcode of direct jmpq is 0xe9.
4286 // The opcode of nop is 0x90.
4288 // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
4289 // relative and since the instruction following the jmpq is now
4290 // the nop, offset the address by 1 byte. The start of the
4291 // relocation also moves ahead by 1 byte.
4292 Reloc_funcs::pcrela32(&view
[-1], object
, psymval
, addend
,
4300 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
4301 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
4302 - target
->got_size());
4306 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4307 gold_assert(object
->local_has_got_offset(r_sym
,
4308 GOT_TYPE_STANDARD
));
4309 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
4310 - target
->got_size());
4312 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4313 value
= target
->got_plt_section()->address() + got_offset
;
4314 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
4319 case elfcpp::R_X86_64_GOTPCREL64
:
4321 gold_assert(have_got_offset
);
4322 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4323 value
= target
->got_plt_section()->address() + got_offset
;
4324 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
4328 case elfcpp::R_X86_64_COPY
:
4329 case elfcpp::R_X86_64_GLOB_DAT
:
4330 case elfcpp::R_X86_64_JUMP_SLOT
:
4331 case elfcpp::R_X86_64_RELATIVE
:
4332 case elfcpp::R_X86_64_IRELATIVE
:
4333 // These are outstanding tls relocs, which are unexpected when linking
4334 case elfcpp::R_X86_64_TPOFF64
:
4335 case elfcpp::R_X86_64_DTPMOD64
:
4336 case elfcpp::R_X86_64_TLSDESC
:
4337 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4338 _("unexpected reloc %u in object file"),
4342 // These are initial tls relocs, which are expected when linking
4343 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
4344 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
4345 case elfcpp::R_X86_64_TLSDESC_CALL
:
4346 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4347 case elfcpp::R_X86_64_DTPOFF32
:
4348 case elfcpp::R_X86_64_DTPOFF64
:
4349 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4350 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4351 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
4352 view
, address
, view_size
);
4355 case elfcpp::R_X86_64_SIZE32
:
4356 case elfcpp::R_X86_64_SIZE64
:
4358 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4359 _("unsupported reloc %u"),
4364 if (rstatus
== Reloc_funcs::RELOC_OVERFLOW
)
4368 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4369 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4370 _("relocation overflow: "
4371 "reference to local symbol %u in %s"),
4372 r_sym
, object
->name().c_str());
4374 else if (gsym
->is_defined() && gsym
->source() == Symbol::FROM_OBJECT
)
4376 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4377 _("relocation overflow: "
4378 "reference to '%s' defined in %s"),
4380 gsym
->object()->name().c_str());
4384 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4385 _("relocation overflow: reference to '%s'"),
4393 // Perform a TLS relocation.
4397 Target_x86_64
<size
>::Relocate::relocate_tls(
4398 const Relocate_info
<size
, false>* relinfo
,
4399 Target_x86_64
<size
>* target
,
4401 const elfcpp::Rela
<size
, false>& rela
,
4402 unsigned int r_type
,
4403 const Sized_symbol
<size
>* gsym
,
4404 const Symbol_value
<size
>* psymval
,
4405 unsigned char* view
,
4406 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4407 section_size_type view_size
)
4409 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
4411 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
4412 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4413 elfcpp::Shdr
<size
, false> data_shdr(relinfo
->data_shdr
);
4414 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
4416 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
4418 const bool is_final
= (gsym
== NULL
4419 ? !parameters
->options().shared()
4420 : gsym
->final_value_is_known());
4421 tls::Tls_optimization optimized_type
4422 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
4425 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
4426 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
4428 // If this code sequence is used in a non-executable section,
4429 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
4430 // on the assumption that it's being used by itself in a debug
4431 // section. Therefore, in the unlikely event that the code
4432 // sequence appears in a non-executable section, we simply
4433 // leave it unoptimized.
4434 optimized_type
= tls::TLSOPT_NONE
;
4436 if (optimized_type
== tls::TLSOPT_TO_LE
)
4438 if (tls_segment
== NULL
)
4440 gold_assert(parameters
->errors()->error_count() > 0
4441 || issue_undefined_symbol_error(gsym
));
4444 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
4445 rela
, r_type
, value
, view
,
4451 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
4452 ? GOT_TYPE_TLS_OFFSET
4453 : GOT_TYPE_TLS_PAIR
);
4454 unsigned int got_offset
;
4457 gold_assert(gsym
->has_got_offset(got_type
));
4458 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
4462 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4463 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
4464 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
4465 - target
->got_size());
4467 if (optimized_type
== tls::TLSOPT_TO_IE
)
4469 value
= target
->got_plt_section()->address() + got_offset
;
4470 this->tls_gd_to_ie(relinfo
, relnum
, rela
, r_type
,
4471 value
, view
, address
, view_size
);
4474 else if (optimized_type
== tls::TLSOPT_NONE
)
4476 // Relocate the field with the offset of the pair of GOT
4478 value
= target
->got_plt_section()->address() + got_offset
;
4479 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
4484 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4485 _("unsupported reloc %u"), r_type
);
4488 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
4489 case elfcpp::R_X86_64_TLSDESC_CALL
:
4490 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
4492 // See above comment for R_X86_64_TLSGD.
4493 optimized_type
= tls::TLSOPT_NONE
;
4495 if (optimized_type
== tls::TLSOPT_TO_LE
)
4497 if (tls_segment
== NULL
)
4499 gold_assert(parameters
->errors()->error_count() > 0
4500 || issue_undefined_symbol_error(gsym
));
4503 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
4504 rela
, r_type
, value
, view
,
4510 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
4511 ? GOT_TYPE_TLS_OFFSET
4512 : GOT_TYPE_TLS_DESC
);
4513 unsigned int got_offset
= 0;
4514 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
4515 && optimized_type
== tls::TLSOPT_NONE
)
4517 // We created GOT entries in the .got.tlsdesc portion of
4518 // the .got.plt section, but the offset stored in the
4519 // symbol is the offset within .got.tlsdesc.
4520 got_offset
= (target
->got_size()
4521 + target
->got_plt_section()->data_size());
4525 gold_assert(gsym
->has_got_offset(got_type
));
4526 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
4530 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4531 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
4532 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
4533 - target
->got_size());
4535 if (optimized_type
== tls::TLSOPT_TO_IE
)
4537 value
= target
->got_plt_section()->address() + got_offset
;
4538 this->tls_desc_gd_to_ie(relinfo
, relnum
,
4539 rela
, r_type
, value
, view
, address
,
4543 else if (optimized_type
== tls::TLSOPT_NONE
)
4545 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4547 // Relocate the field with the offset of the pair of GOT
4549 value
= target
->got_plt_section()->address() + got_offset
;
4550 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
4556 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4557 _("unsupported reloc %u"), r_type
);
4560 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4561 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
4563 // See above comment for R_X86_64_TLSGD.
4564 optimized_type
= tls::TLSOPT_NONE
;
4566 if (optimized_type
== tls::TLSOPT_TO_LE
)
4568 if (tls_segment
== NULL
)
4570 gold_assert(parameters
->errors()->error_count() > 0
4571 || issue_undefined_symbol_error(gsym
));
4574 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
4575 value
, view
, view_size
);
4578 else if (optimized_type
== tls::TLSOPT_NONE
)
4580 // Relocate the field with the offset of the GOT entry for
4581 // the module index.
4582 unsigned int got_offset
;
4583 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
4584 - target
->got_size());
4585 value
= target
->got_plt_section()->address() + got_offset
;
4586 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
4590 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4591 _("unsupported reloc %u"), r_type
);
4594 case elfcpp::R_X86_64_DTPOFF32
:
4595 // This relocation type is used in debugging information.
4596 // In that case we need to not optimize the value. If the
4597 // section is not executable, then we assume we should not
4598 // optimize this reloc. See comments above for R_X86_64_TLSGD,
4599 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
4601 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
4603 if (tls_segment
== NULL
)
4605 gold_assert(parameters
->errors()->error_count() > 0
4606 || issue_undefined_symbol_error(gsym
));
4609 value
-= tls_segment
->memsz();
4611 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
4614 case elfcpp::R_X86_64_DTPOFF64
:
4615 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
4616 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
4618 if (tls_segment
== NULL
)
4620 gold_assert(parameters
->errors()->error_count() > 0
4621 || issue_undefined_symbol_error(gsym
));
4624 value
-= tls_segment
->memsz();
4626 Relocate_functions
<size
, false>::rela64(view
, value
, addend
);
4629 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4631 && gsym
->is_undefined()
4632 && parameters
->options().output_is_executable())
4634 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
4636 r_type
, value
, view
,
4640 else if (optimized_type
== tls::TLSOPT_TO_LE
)
4642 if (tls_segment
== NULL
)
4644 gold_assert(parameters
->errors()->error_count() > 0
4645 || issue_undefined_symbol_error(gsym
));
4648 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
4650 r_type
, value
, view
,
4654 else if (optimized_type
== tls::TLSOPT_NONE
)
4656 // Relocate the field with the offset of the GOT entry for
4657 // the tp-relative offset of the symbol.
4658 unsigned int got_offset
;
4661 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
4662 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
4663 - target
->got_size());
4667 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4668 gold_assert(object
->local_has_got_offset(r_sym
,
4669 GOT_TYPE_TLS_OFFSET
));
4670 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
4671 - target
->got_size());
4673 value
= target
->got_plt_section()->address() + got_offset
;
4674 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
4678 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4679 _("unsupported reloc type %u"),
4683 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4684 if (tls_segment
== NULL
)
4686 gold_assert(parameters
->errors()->error_count() > 0
4687 || issue_undefined_symbol_error(gsym
));
4690 value
-= tls_segment
->memsz();
4691 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
4696 // Do a relocation in which we convert a TLS General-Dynamic to an
4701 Target_x86_64
<size
>::Relocate::tls_gd_to_ie(
4702 const Relocate_info
<size
, false>* relinfo
,
4704 const elfcpp::Rela
<size
, false>& rela
,
4706 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4707 unsigned char* view
,
4708 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4709 section_size_type view_size
)
4712 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4713 // .word 0x6666; rex64; call __tls_get_addr@PLT
4714 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4715 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4716 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4717 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4719 // leaq foo@tlsgd(%rip),%rdi;
4720 // .word 0x6666; rex64; call __tls_get_addr@PLT
4721 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4722 // leaq foo@tlsgd(%rip),%rdi;
4723 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4724 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4726 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
4727 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4728 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0
4729 || memcmp(view
+ 4, "\x66\x48\xff", 3) == 0));
4733 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4735 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4736 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
4737 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4742 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4744 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4745 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
4746 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4750 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4751 Relocate_functions
<size
, false>::pcrela32(view
+ 8, value
, addend
- 8,
4754 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4756 this->skip_call_tls_get_addr_
= true;
4759 // Do a relocation in which we convert a TLS General-Dynamic to a
4764 Target_x86_64
<size
>::Relocate::tls_gd_to_le(
4765 const Relocate_info
<size
, false>* relinfo
,
4767 Output_segment
* tls_segment
,
4768 const elfcpp::Rela
<size
, false>& rela
,
4770 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4771 unsigned char* view
,
4772 section_size_type view_size
)
4775 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4776 // .word 0x6666; rex64; call __tls_get_addr@PLT
4777 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4778 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4779 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4780 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4782 // leaq foo@tlsgd(%rip),%rdi;
4783 // .word 0x6666; rex64; call __tls_get_addr@PLT
4784 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4785 // leaq foo@tlsgd(%rip),%rdi;
4786 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4787 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4789 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
4790 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4791 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0
4792 || memcmp(view
+ 4, "\x66\x48\xff", 3) == 0));
4796 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4798 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4799 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
4800 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4805 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
4807 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4808 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
4810 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4814 value
-= tls_segment
->memsz();
4815 Relocate_functions
<size
, false>::rela32(view
+ 8, value
, 0);
4817 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4819 this->skip_call_tls_get_addr_
= true;
4822 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4826 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_ie(
4827 const Relocate_info
<size
, false>* relinfo
,
4829 const elfcpp::Rela
<size
, false>& rela
,
4830 unsigned int r_type
,
4831 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4832 unsigned char* view
,
4833 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4834 section_size_type view_size
)
4836 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4838 // leaq foo@tlsdesc(%rip), %rax
4839 // ==> movq foo@gottpoff(%rip), %rax
4840 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4841 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4842 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4843 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
4845 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4846 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
4850 // call *foo@tlscall(%rax)
4852 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
4853 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
4854 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4855 view
[0] == 0xff && view
[1] == 0x10);
4861 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4865 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_le(
4866 const Relocate_info
<size
, false>* relinfo
,
4868 Output_segment
* tls_segment
,
4869 const elfcpp::Rela
<size
, false>& rela
,
4870 unsigned int r_type
,
4871 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4872 unsigned char* view
,
4873 section_size_type view_size
)
4875 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
4877 // leaq foo@tlsdesc(%rip), %rax
4878 // ==> movq foo@tpoff, %rax
4879 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4880 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4881 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4882 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
4885 value
-= tls_segment
->memsz();
4886 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
4890 // call *foo@tlscall(%rax)
4892 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
4893 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
4894 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4895 view
[0] == 0xff && view
[1] == 0x10);
4903 Target_x86_64
<size
>::Relocate::tls_ld_to_le(
4904 const Relocate_info
<size
, false>* relinfo
,
4907 const elfcpp::Rela
<size
, false>& rela
,
4909 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
4910 unsigned char* view
,
4911 section_size_type view_size
)
4913 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4915 // ... leq foo@dtpoff(%rax),%reg
4916 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4918 // ... leq foo@dtpoff(%rax),%reg
4919 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4920 // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
4922 // ... leq foo@dtpoff(%rax),%reg
4923 // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4925 // ... leq foo@dtpoff(%rax),%reg
4926 // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4928 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4929 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
4931 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4932 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
4934 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
4935 view
[4] == 0xe8 || view
[4] == 0xff);
4937 if (view
[4] == 0xe8)
4940 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4942 memcpy(view
- 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4947 memcpy(view
- 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
4950 memcpy(view
- 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
4954 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4956 this->skip_call_tls_get_addr_
= true;
4959 // Do a relocation in which we convert a TLS Initial-Exec to a
4964 Target_x86_64
<size
>::Relocate::tls_ie_to_le(
4965 const Relocate_info
<size
, false>* relinfo
,
4967 Output_segment
* tls_segment
,
4968 const elfcpp::Rela
<size
, false>& rela
,
4970 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
4971 unsigned char* view
,
4972 section_size_type view_size
)
4974 // We need to examine the opcodes to figure out which instruction we
4977 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4978 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4980 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
4981 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
4983 unsigned char op1
= view
[-3];
4984 unsigned char op2
= view
[-2];
4985 unsigned char op3
= view
[-1];
4986 unsigned char reg
= op3
>> 3;
4993 else if (size
== 32 && op1
== 0x44)
4996 view
[-1] = 0xc0 | reg
;
5000 // Special handling for %rsp.
5003 else if (size
== 32 && op1
== 0x44)
5006 view
[-1] = 0xc0 | reg
;
5013 else if (size
== 32 && op1
== 0x44)
5016 view
[-1] = 0x80 | reg
| (reg
<< 3);
5019 if (tls_segment
!= NULL
)
5020 value
-= tls_segment
->memsz();
5021 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
5024 // Relocate section data.
5028 Target_x86_64
<size
>::relocate_section(
5029 const Relocate_info
<size
, false>* relinfo
,
5030 unsigned int sh_type
,
5031 const unsigned char* prelocs
,
5033 Output_section
* output_section
,
5034 bool needs_special_offset_handling
,
5035 unsigned char* view
,
5036 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5037 section_size_type view_size
,
5038 const Reloc_symbol_changes
* reloc_symbol_changes
)
5040 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5043 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5045 gold::relocate_section
<size
, false, Target_x86_64
<size
>, Relocate
,
5046 gold::Default_comdat_behavior
, Classify_reloc
>(
5052 needs_special_offset_handling
,
5056 reloc_symbol_changes
);
5059 // Apply an incremental relocation. Incremental relocations always refer
5060 // to global symbols.
5064 Target_x86_64
<size
>::apply_relocation(
5065 const Relocate_info
<size
, false>* relinfo
,
5066 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
5067 unsigned int r_type
,
5068 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
5070 unsigned char* view
,
5071 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5072 section_size_type view_size
)
5074 gold::apply_relocation
<size
, false, Target_x86_64
<size
>,
5075 typename Target_x86_64
<size
>::Relocate
>(
5087 // Scan the relocs during a relocatable link.
5091 Target_x86_64
<size
>::scan_relocatable_relocs(
5092 Symbol_table
* symtab
,
5094 Sized_relobj_file
<size
, false>* object
,
5095 unsigned int data_shndx
,
5096 unsigned int sh_type
,
5097 const unsigned char* prelocs
,
5099 Output_section
* output_section
,
5100 bool needs_special_offset_handling
,
5101 size_t local_symbol_count
,
5102 const unsigned char* plocal_symbols
,
5103 Relocatable_relocs
* rr
)
5105 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5107 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
5108 Scan_relocatable_relocs
;
5110 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5112 gold::scan_relocatable_relocs
<size
, false, Scan_relocatable_relocs
>(
5120 needs_special_offset_handling
,
5126 // Scan the relocs for --emit-relocs.
5130 Target_x86_64
<size
>::emit_relocs_scan(
5131 Symbol_table
* symtab
,
5133 Sized_relobj_file
<size
, false>* object
,
5134 unsigned int data_shndx
,
5135 unsigned int sh_type
,
5136 const unsigned char* prelocs
,
5138 Output_section
* output_section
,
5139 bool needs_special_offset_handling
,
5140 size_t local_symbol_count
,
5141 const unsigned char* plocal_syms
,
5142 Relocatable_relocs
* rr
)
5144 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5146 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
5147 Emit_relocs_strategy
;
5149 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5151 gold::scan_relocatable_relocs
<size
, false, Emit_relocs_strategy
>(
5159 needs_special_offset_handling
,
5165 // Relocate a section during a relocatable link.
5169 Target_x86_64
<size
>::relocate_relocs(
5170 const Relocate_info
<size
, false>* relinfo
,
5171 unsigned int sh_type
,
5172 const unsigned char* prelocs
,
5174 Output_section
* output_section
,
5175 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
5176 unsigned char* view
,
5177 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
5178 section_size_type view_size
,
5179 unsigned char* reloc_view
,
5180 section_size_type reloc_view_size
)
5182 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5185 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5187 gold::relocate_relocs
<size
, false, Classify_reloc
>(
5192 offset_in_output_section
,
5200 // Return the value to use for a dynamic which requires special
5201 // treatment. This is how we support equality comparisons of function
5202 // pointers across shared library boundaries, as described in the
5203 // processor specific ABI supplement.
5207 Target_x86_64
<size
>::do_dynsym_value(const Symbol
* gsym
) const
5209 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
5210 return this->plt_address_for_global(gsym
);
5213 // Return a string used to fill a code section with nops to take up
5214 // the specified length.
5218 Target_x86_64
<size
>::do_code_fill(section_size_type length
) const
5222 // Build a jmpq instruction to skip over the bytes.
5223 unsigned char jmp
[5];
5225 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
5226 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
5227 + std::string(length
- 5, static_cast<char>(0x90)));
5230 // Nop sequences of various lengths.
5231 const char nop1
[1] = { '\x90' }; // nop
5232 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
5233 const char nop3
[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5234 const char nop4
[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
5236 const char nop5
[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
5238 const char nop6
[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
5239 '\x44', '\x00', '\x00' };
5240 const char nop7
[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
5241 '\x00', '\x00', '\x00',
5243 const char nop8
[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
5244 '\x00', '\x00', '\x00',
5246 const char nop9
[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
5247 '\x84', '\x00', '\x00',
5248 '\x00', '\x00', '\x00' };
5249 const char nop10
[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5250 '\x1f', '\x84', '\x00',
5251 '\x00', '\x00', '\x00',
5253 const char nop11
[11] = { '\x66', '\x66', '\x2e', // data16
5254 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5255 '\x00', '\x00', '\x00',
5257 const char nop12
[12] = { '\x66', '\x66', '\x66', // data16; data16
5258 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5259 '\x84', '\x00', '\x00',
5260 '\x00', '\x00', '\x00' };
5261 const char nop13
[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5262 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5263 '\x1f', '\x84', '\x00',
5264 '\x00', '\x00', '\x00',
5266 const char nop14
[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5267 '\x66', '\x66', '\x2e', // data16
5268 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5269 '\x00', '\x00', '\x00',
5271 const char nop15
[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5272 '\x66', '\x66', '\x66', // data16; data16
5273 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5274 '\x84', '\x00', '\x00',
5275 '\x00', '\x00', '\x00' };
5277 const char* nops
[16] = {
5279 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
5280 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
5283 return std::string(nops
[length
], length
);
5286 // Return the addend to use for a target specific relocation. The
5287 // only target specific relocation is R_X86_64_TLSDESC for a local
5288 // symbol. We want to set the addend is the offset of the local
5289 // symbol in the TLS segment.
5293 Target_x86_64
<size
>::do_reloc_addend(void* arg
, unsigned int r_type
,
5296 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
5297 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
5298 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
5299 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
5300 const Symbol_value
<size
>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
5301 gold_assert(psymval
->is_tls_symbol());
5302 // The value of a TLS symbol is the offset in the TLS segment.
5303 return psymval
->value(ti
.object
, 0);
5306 // Return the value to use for the base of a DW_EH_PE_datarel offset
5307 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
5308 // assembler can not write out the difference between two labels in
5309 // different sections, so instead of using a pc-relative value they
5310 // use an offset from the GOT.
5314 Target_x86_64
<size
>::do_ehframe_datarel_base() const
5316 gold_assert(this->global_offset_table_
!= NULL
);
5317 Symbol
* sym
= this->global_offset_table_
;
5318 Sized_symbol
<size
>* ssym
= static_cast<Sized_symbol
<size
>*>(sym
);
5319 return ssym
->value();
5322 // FNOFFSET in section SHNDX in OBJECT is the start of a function
5323 // compiled with -fsplit-stack. The function calls non-split-stack
5324 // code. We have to change the function so that it always ensures
5325 // that it has enough stack space to run some random function.
5327 static const unsigned char cmp_insn_32
[] = { 0x64, 0x3b, 0x24, 0x25 };
5328 static const unsigned char lea_r10_insn_32
[] = { 0x44, 0x8d, 0x94, 0x24 };
5329 static const unsigned char lea_r11_insn_32
[] = { 0x44, 0x8d, 0x9c, 0x24 };
5331 static const unsigned char cmp_insn_64
[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
5332 static const unsigned char lea_r10_insn_64
[] = { 0x4c, 0x8d, 0x94, 0x24 };
5333 static const unsigned char lea_r11_insn_64
[] = { 0x4c, 0x8d, 0x9c, 0x24 };
5337 Target_x86_64
<size
>::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
5338 section_offset_type fnoffset
,
5339 section_size_type fnsize
,
5340 const unsigned char*,
5342 unsigned char* view
,
5343 section_size_type view_size
,
5345 std::string
* to
) const
5347 const char* const cmp_insn
= reinterpret_cast<const char*>
5348 (size
== 32 ? cmp_insn_32
: cmp_insn_64
);
5349 const char* const lea_r10_insn
= reinterpret_cast<const char*>
5350 (size
== 32 ? lea_r10_insn_32
: lea_r10_insn_64
);
5351 const char* const lea_r11_insn
= reinterpret_cast<const char*>
5352 (size
== 32 ? lea_r11_insn_32
: lea_r11_insn_64
);
5354 const size_t cmp_insn_len
=
5355 (size
== 32 ? sizeof(cmp_insn_32
) : sizeof(cmp_insn_64
));
5356 const size_t lea_r10_insn_len
=
5357 (size
== 32 ? sizeof(lea_r10_insn_32
) : sizeof(lea_r10_insn_64
));
5358 const size_t lea_r11_insn_len
=
5359 (size
== 32 ? sizeof(lea_r11_insn_32
) : sizeof(lea_r11_insn_64
));
5360 const size_t nop_len
= (size
== 32 ? 7 : 8);
5362 // The function starts with a comparison of the stack pointer and a
5363 // field in the TCB. This is followed by a jump.
5366 if (this->match_view(view
, view_size
, fnoffset
, cmp_insn
, cmp_insn_len
)
5367 && fnsize
> nop_len
+ 1)
5369 // We will call __morestack if the carry flag is set after this
5370 // comparison. We turn the comparison into an stc instruction
5372 view
[fnoffset
] = '\xf9';
5373 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, nop_len
);
5375 // lea NN(%rsp),%r10
5376 // lea NN(%rsp),%r11
5377 else if ((this->match_view(view
, view_size
, fnoffset
,
5378 lea_r10_insn
, lea_r10_insn_len
)
5379 || this->match_view(view
, view_size
, fnoffset
,
5380 lea_r11_insn
, lea_r11_insn_len
))
5383 // This is loading an offset from the stack pointer for a
5384 // comparison. The offset is negative, so we decrease the
5385 // offset by the amount of space we need for the stack. This
5386 // means we will avoid calling __morestack if there happens to
5387 // be plenty of space on the stack already.
5388 unsigned char* pval
= view
+ fnoffset
+ 4;
5389 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
5390 val
-= parameters
->options().split_stack_adjust_size();
5391 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
5395 if (!object
->has_no_split_stack())
5396 object
->error(_("failed to match split-stack sequence at "
5397 "section %u offset %0zx"),
5398 shndx
, static_cast<size_t>(fnoffset
));
5402 // We have to change the function so that it calls
5403 // __morestack_non_split instead of __morestack. The former will
5404 // allocate additional stack space.
5405 *from
= "__morestack";
5406 *to
= "__morestack_non_split";
5409 // The selector for x86_64 object files. Note this is never instantiated
5410 // directly. It's only used in Target_selector_x86_64_nacl, below.
5413 class Target_selector_x86_64
: public Target_selector_freebsd
5416 Target_selector_x86_64()
5417 : Target_selector_freebsd(elfcpp::EM_X86_64
, size
, false,
5419 ? "elf64-x86-64" : "elf32-x86-64"),
5421 ? "elf64-x86-64-freebsd"
5422 : "elf32-x86-64-freebsd"),
5423 (size
== 64 ? "elf_x86_64" : "elf32_x86_64"))
5427 do_instantiate_target()
5428 { return new Target_x86_64
<size
>(); }
5432 // NaCl variant. It uses different PLT contents.
5435 class Output_data_plt_x86_64_nacl
: public Output_data_plt_x86_64
<size
>
5438 Output_data_plt_x86_64_nacl(Layout
* layout
,
5439 Output_data_got
<64, false>* got
,
5440 Output_data_got_plt_x86_64
* got_plt
,
5441 Output_data_space
* got_irelative
)
5442 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
5443 got
, got_plt
, got_irelative
)
5446 Output_data_plt_x86_64_nacl(Layout
* layout
,
5447 Output_data_got
<64, false>* got
,
5448 Output_data_got_plt_x86_64
* got_plt
,
5449 Output_data_space
* got_irelative
,
5450 unsigned int plt_count
)
5451 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
5452 got
, got_plt
, got_irelative
,
5457 virtual unsigned int
5458 do_get_plt_entry_size() const
5459 { return plt_entry_size
; }
5462 do_add_eh_frame(Layout
* layout
)
5464 layout
->add_eh_frame_for_plt(this,
5465 this->plt_eh_frame_cie
,
5466 this->plt_eh_frame_cie_size
,
5468 plt_eh_frame_fde_size
);
5472 do_fill_first_plt_entry(unsigned char* pov
,
5473 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
5474 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
5476 virtual unsigned int
5477 do_fill_plt_entry(unsigned char* pov
,
5478 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
5479 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
5480 unsigned int got_offset
,
5481 unsigned int plt_offset
,
5482 unsigned int plt_index
);
5485 do_fill_tlsdesc_entry(unsigned char* pov
,
5486 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
5487 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
5488 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
5489 unsigned int tlsdesc_got_offset
,
5490 unsigned int plt_offset
);
5493 // The size of an entry in the PLT.
5494 static const int plt_entry_size
= 64;
5496 // The first entry in the PLT.
5497 static const unsigned char first_plt_entry
[plt_entry_size
];
5499 // Other entries in the PLT for an executable.
5500 static const unsigned char plt_entry
[plt_entry_size
];
5502 // The reserved TLSDESC entry in the PLT for an executable.
5503 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
5505 // The .eh_frame unwind information for the PLT.
5506 static const int plt_eh_frame_fde_size
= 32;
5507 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
5511 class Target_x86_64_nacl
: public Target_x86_64
<size
>
5514 Target_x86_64_nacl()
5515 : Target_x86_64
<size
>(&x86_64_nacl_info
)
5518 virtual Output_data_plt_x86_64
<size
>*
5519 do_make_data_plt(Layout
* layout
,
5520 Output_data_got
<64, false>* got
,
5521 Output_data_got_plt_x86_64
* got_plt
,
5522 Output_data_space
* got_irelative
)
5524 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
5528 virtual Output_data_plt_x86_64
<size
>*
5529 do_make_data_plt(Layout
* layout
,
5530 Output_data_got
<64, false>* got
,
5531 Output_data_got_plt_x86_64
* got_plt
,
5532 Output_data_space
* got_irelative
,
5533 unsigned int plt_count
)
5535 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
5541 do_code_fill(section_size_type length
) const;
5544 static const Target::Target_info x86_64_nacl_info
;
5548 const Target::Target_info Target_x86_64_nacl
<64>::x86_64_nacl_info
=
5551 false, // is_big_endian
5552 elfcpp::EM_X86_64
, // machine_code
5553 false, // has_make_symbol
5554 false, // has_resolve
5555 true, // has_code_fill
5556 true, // is_default_stack_executable
5557 true, // can_icf_inline_merge_sections
5559 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
5560 0x20000, // default_text_segment_address
5561 0x10000, // abi_pagesize (overridable by -z max-page-size)
5562 0x10000, // common_pagesize (overridable by -z common-page-size)
5563 true, // isolate_execinstr
5564 0x10000000, // rosegment_gap
5565 elfcpp::SHN_UNDEF
, // small_common_shndx
5566 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
5567 0, // small_common_section_flags
5568 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
5569 NULL
, // attributes_section
5570 NULL
, // attributes_vendor
5571 "_start", // entry_symbol_name
5572 32, // hash_entry_size
5576 const Target::Target_info Target_x86_64_nacl
<32>::x86_64_nacl_info
=
5579 false, // is_big_endian
5580 elfcpp::EM_X86_64
, // machine_code
5581 false, // has_make_symbol
5582 false, // has_resolve
5583 true, // has_code_fill
5584 true, // is_default_stack_executable
5585 true, // can_icf_inline_merge_sections
5587 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
5588 0x20000, // default_text_segment_address
5589 0x10000, // abi_pagesize (overridable by -z max-page-size)
5590 0x10000, // common_pagesize (overridable by -z common-page-size)
5591 true, // isolate_execinstr
5592 0x10000000, // rosegment_gap
5593 elfcpp::SHN_UNDEF
, // small_common_shndx
5594 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
5595 0, // small_common_section_flags
5596 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
5597 NULL
, // attributes_section
5598 NULL
, // attributes_vendor
5599 "_start", // entry_symbol_name
5600 32, // hash_entry_size
5603 #define NACLMASK 0xe0 // 32-byte alignment mask.
5605 // The first entry in the PLT.
5609 Output_data_plt_x86_64_nacl
<size
>::first_plt_entry
[plt_entry_size
] =
5611 0xff, 0x35, // pushq contents of memory address
5612 0, 0, 0, 0, // replaced with address of .got + 8
5613 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
5614 0, 0, 0, 0, // replaced with address of .got + 16
5615 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
5616 0x4d, 0x01, 0xfb, // add %r15, %r11
5617 0x41, 0xff, 0xe3, // jmpq *%r11
5619 // 9-byte nop sequence to pad out to the next 32-byte boundary.
5620 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
5622 // 32 bytes of nop to pad out to the standard size
5623 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5624 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5625 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5626 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5627 0x66, // excess data32 prefix
5633 Output_data_plt_x86_64_nacl
<size
>::do_fill_first_plt_entry(
5635 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
5636 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
5638 memcpy(pov
, first_plt_entry
, plt_entry_size
);
5639 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
5641 - (plt_address
+ 2 + 4)));
5642 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
5644 - (plt_address
+ 9 + 4)));
5647 // Subsequent entries in the PLT.
5651 Output_data_plt_x86_64_nacl
<size
>::plt_entry
[plt_entry_size
] =
5653 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
5654 0, 0, 0, 0, // replaced with address of symbol in .got
5655 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
5656 0x4d, 0x01, 0xfb, // add %r15, %r11
5657 0x41, 0xff, 0xe3, // jmpq *%r11
5659 // 15-byte nop sequence to pad out to the next 32-byte boundary.
5660 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5661 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5663 // Lazy GOT entries point here (32-byte aligned).
5664 0x68, // pushq immediate
5665 0, 0, 0, 0, // replaced with index into relocation table
5666 0xe9, // jmp relative
5667 0, 0, 0, 0, // replaced with offset to start of .plt0
5669 // 22 bytes of nop to pad out to the standard size.
5670 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5671 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5672 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
5677 Output_data_plt_x86_64_nacl
<size
>::do_fill_plt_entry(
5679 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
5680 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
5681 unsigned int got_offset
,
5682 unsigned int plt_offset
,
5683 unsigned int plt_index
)
5685 memcpy(pov
, plt_entry
, plt_entry_size
);
5686 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3,
5687 (got_address
+ got_offset
5688 - (plt_address
+ plt_offset
5691 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_index
);
5692 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 38,
5693 - (plt_offset
+ 38 + 4));
5698 // The reserved TLSDESC entry in the PLT.
5702 Output_data_plt_x86_64_nacl
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
5704 0xff, 0x35, // pushq x(%rip)
5705 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
5706 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
5707 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
5708 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
5709 0x4d, 0x01, 0xfb, // add %r15, %r11
5710 0x41, 0xff, 0xe3, // jmpq *%r11
5712 // 41 bytes of nop to pad out to the standard size.
5713 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5714 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5715 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5716 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5717 0x66, 0x66, // excess data32 prefixes
5718 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5723 Output_data_plt_x86_64_nacl
<size
>::do_fill_tlsdesc_entry(
5725 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
5726 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
5727 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
5728 unsigned int tlsdesc_got_offset
,
5729 unsigned int plt_offset
)
5731 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
5732 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
5734 - (plt_address
+ plt_offset
5736 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
5738 + tlsdesc_got_offset
5739 - (plt_address
+ plt_offset
5743 // The .eh_frame unwind information for the PLT.
5747 Output_data_plt_x86_64_nacl
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
5749 0, 0, 0, 0, // Replaced with offset to .plt.
5750 0, 0, 0, 0, // Replaced with size of .plt.
5751 0, // Augmentation size.
5752 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
5753 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
5754 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
5755 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
5756 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
5757 13, // Block length.
5758 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
5759 elfcpp::DW_OP_breg16
, 0, // Push %rip.
5760 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
5761 elfcpp::DW_OP_and
, // & (%rip & 0x3f).
5762 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
5763 elfcpp::DW_OP_ge
, // >= ((%rip & 0x3f) >= 0x25)
5764 elfcpp::DW_OP_lit3
, // Push 3.
5765 elfcpp::DW_OP_shl
, // << (((%rip & 0x3f) >= 0x25) << 3)
5766 elfcpp::DW_OP_plus
, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5767 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
5771 // Return a string used to fill a code section with nops.
5772 // For NaCl, long NOPs are only valid if they do not cross
5773 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5776 Target_x86_64_nacl
<size
>::do_code_fill(section_size_type length
) const
5778 return std::string(length
, static_cast<char>(0x90));
5781 // The selector for x86_64-nacl object files.
5784 class Target_selector_x86_64_nacl
5785 : public Target_selector_nacl
<Target_selector_x86_64
<size
>,
5786 Target_x86_64_nacl
<size
> >
5789 Target_selector_x86_64_nacl()
5790 : Target_selector_nacl
<Target_selector_x86_64
<size
>,
5791 Target_x86_64_nacl
<size
> >("x86-64",
5793 ? "elf64-x86-64-nacl"
5794 : "elf32-x86-64-nacl",
5797 : "elf32_x86_64_nacl")
5801 Target_selector_x86_64_nacl
<64> target_selector_x86_64
;
5802 Target_selector_x86_64_nacl
<32> target_selector_x32
;
5804 } // End anonymous namespace.