1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright (C) 2006-2020 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
];
545 // We use this PLT when Indirect Branch Tracking (IBT) is enabled.
548 class Output_data_plt_x86_64_ibt
: public Output_data_plt_x86_64
<size
>
551 Output_data_plt_x86_64_ibt(Layout
* layout
,
552 Output_data_got
<64, false>* got
,
553 Output_data_got_plt_x86_64
* got_plt
,
554 Output_data_space
* got_irelative
)
555 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
556 got
, got_plt
, got_irelative
),
560 Output_data_plt_x86_64_ibt(Layout
* layout
,
561 Output_data_got
<64, false>* got
,
562 Output_data_got_plt_x86_64
* got_plt
,
563 Output_data_space
* got_irelative
,
564 unsigned int plt_count
)
565 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
566 got
, got_plt
, got_irelative
,
573 do_get_plt_entry_size() const
574 { return plt_entry_size
; }
576 // Return the PLT address to use for a global symbol.
578 do_address_for_global(const Symbol
*);
580 // Return the PLT address to use for a local symbol.
582 do_address_for_local(const Relobj
*, unsigned int symndx
);
585 do_add_eh_frame(Layout
* layout
)
587 layout
->add_eh_frame_for_plt(this,
588 this->plt_eh_frame_cie
,
589 this->plt_eh_frame_cie_size
,
591 plt_eh_frame_fde_size
);
595 do_fill_first_plt_entry(unsigned char* pov
,
596 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
597 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
600 do_fill_plt_entry(unsigned char* pov
,
601 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
602 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
603 unsigned int got_offset
,
604 unsigned int plt_offset
,
605 unsigned int plt_index
);
608 do_fill_tlsdesc_entry(unsigned char* pov
,
609 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
610 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
611 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
612 unsigned int tlsdesc_got_offset
,
613 unsigned int plt_offset
);
616 fill_aplt_entry(unsigned char* pov
,
617 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
618 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
619 unsigned int got_offset
,
620 unsigned int plt_offset
,
621 unsigned int plt_index
);
624 // Set the final size.
626 set_final_data_size();
628 // Write out the BND PLT data.
630 do_write(Output_file
*);
632 // Offset of the Additional PLT (if using -z bndplt).
633 unsigned int aplt_offset_
;
635 // The size of an entry in the PLT.
636 static const int plt_entry_size
= 16;
638 // The size of an entry in the additional PLT.
639 static const int aplt_entry_size
= 16;
641 // The first entry in the PLT.
642 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
643 // procedure linkage table for both programs and shared objects."
644 static const unsigned char first_plt_entry
[plt_entry_size
];
646 // Other entries in the PLT for an executable.
647 static const unsigned char plt_entry
[plt_entry_size
];
649 // Entries in the additional PLT.
650 static const unsigned char aplt_entry
[aplt_entry_size
];
652 // The reserved TLSDESC entry in the PLT for an executable.
653 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
655 // The .eh_frame unwind information for the PLT.
656 static const int plt_eh_frame_fde_size
= 32;
657 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
664 Lazy_view(Sized_relobj_file
<size
, false>* object
, unsigned int data_shndx
)
665 : object_(object
), data_shndx_(data_shndx
), view_(NULL
), view_size_(0)
669 operator[](size_t offset
)
671 if (this->view_
== NULL
)
672 this->view_
= this->object_
->section_contents(this->data_shndx_
,
675 if (offset
>= this->view_size_
)
677 return this->view_
[offset
];
681 Sized_relobj_file
<size
, false>* object_
;
682 unsigned int data_shndx_
;
683 const unsigned char* view_
;
684 section_size_type view_size_
;
687 // The x86_64 target class.
689 // http://www.x86-64.org/documentation/abi.pdf
690 // TLS info comes from
691 // http://people.redhat.com/drepper/tls.pdf
692 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
695 class Target_x86_64
: public Sized_target
<size
, false>
698 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
699 // uses only Elf64_Rela relocation entries with explicit addends."
700 typedef Output_data_reloc
<elfcpp::SHT_RELA
, true, size
, false> Reloc_section
;
702 Target_x86_64(const Target::Target_info
* info
= &x86_64_info
)
703 : Sized_target
<size
, false>(info
),
704 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
705 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rela_dyn_(NULL
),
706 rela_irelative_(NULL
), copy_relocs_(elfcpp::R_X86_64_COPY
),
707 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
708 tls_base_symbol_defined_(false), isa_1_used_(0), isa_1_needed_(0),
709 feature_1_(0), object_isa_1_used_(0), object_feature_1_(0),
710 seen_first_object_(false)
713 // Hook for a new output section.
715 do_new_output_section(Output_section
*) const;
717 // Scan the relocations to look for symbol adjustments.
719 gc_process_relocs(Symbol_table
* symtab
,
721 Sized_relobj_file
<size
, false>* object
,
722 unsigned int data_shndx
,
723 unsigned int sh_type
,
724 const unsigned char* prelocs
,
726 Output_section
* output_section
,
727 bool needs_special_offset_handling
,
728 size_t local_symbol_count
,
729 const unsigned char* plocal_symbols
);
731 // Scan the relocations to look for symbol adjustments.
733 scan_relocs(Symbol_table
* symtab
,
735 Sized_relobj_file
<size
, false>* object
,
736 unsigned int data_shndx
,
737 unsigned int sh_type
,
738 const unsigned char* prelocs
,
740 Output_section
* output_section
,
741 bool needs_special_offset_handling
,
742 size_t local_symbol_count
,
743 const unsigned char* plocal_symbols
);
745 // Finalize the sections.
747 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
749 // Return the value to use for a dynamic which requires special
752 do_dynsym_value(const Symbol
*) const;
754 // Relocate a section.
756 relocate_section(const Relocate_info
<size
, false>*,
757 unsigned int sh_type
,
758 const unsigned char* prelocs
,
760 Output_section
* output_section
,
761 bool needs_special_offset_handling
,
763 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
764 section_size_type view_size
,
765 const Reloc_symbol_changes
*);
767 // Scan the relocs during a relocatable link.
769 scan_relocatable_relocs(Symbol_table
* symtab
,
771 Sized_relobj_file
<size
, false>* object
,
772 unsigned int data_shndx
,
773 unsigned int sh_type
,
774 const unsigned char* prelocs
,
776 Output_section
* output_section
,
777 bool needs_special_offset_handling
,
778 size_t local_symbol_count
,
779 const unsigned char* plocal_symbols
,
780 Relocatable_relocs
*);
782 // Scan the relocs for --emit-relocs.
784 emit_relocs_scan(Symbol_table
* symtab
,
786 Sized_relobj_file
<size
, false>* object
,
787 unsigned int data_shndx
,
788 unsigned int sh_type
,
789 const unsigned char* prelocs
,
791 Output_section
* output_section
,
792 bool needs_special_offset_handling
,
793 size_t local_symbol_count
,
794 const unsigned char* plocal_syms
,
795 Relocatable_relocs
* rr
);
797 // Emit relocations for a section.
800 const Relocate_info
<size
, false>*,
801 unsigned int sh_type
,
802 const unsigned char* prelocs
,
804 Output_section
* output_section
,
805 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
807 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
808 section_size_type view_size
,
809 unsigned char* reloc_view
,
810 section_size_type reloc_view_size
);
812 // Return a string used to fill a code section with nops.
814 do_code_fill(section_size_type length
) const;
816 // Return whether SYM is defined by the ABI.
818 do_is_defined_by_abi(const Symbol
* sym
) const
819 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
821 // Return the symbol index to use for a target specific relocation.
822 // The only target specific relocation is R_X86_64_TLSDESC for a
823 // local symbol, which is an absolute reloc.
825 do_reloc_symbol_index(void*, unsigned int r_type
) const
827 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
831 // Return the addend to use for a target specific relocation.
833 do_reloc_addend(void* arg
, unsigned int r_type
, uint64_t addend
) const;
835 // Return the PLT section.
837 do_plt_address_for_global(const Symbol
* gsym
) const
838 { return this->plt_section()->address_for_global(gsym
); }
841 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
842 { return this->plt_section()->address_for_local(relobj
, symndx
); }
844 // This function should be defined in targets that can use relocation
845 // types to determine (implemented in local_reloc_may_be_function_pointer
846 // and global_reloc_may_be_function_pointer)
847 // if a function's pointer is taken. ICF uses this in safe mode to only
848 // fold those functions whose pointer is defintely not taken. For x86_64
849 // pie binaries, safe ICF cannot be done by looking at only relocation
850 // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
851 // opcode is checked as well to distinguish a function call from taking
852 // a function's pointer.
854 do_can_check_for_function_pointers() const
857 // Return the base for a DW_EH_PE_datarel encoding.
859 do_ehframe_datarel_base() const;
861 // Adjust -fsplit-stack code which calls non-split-stack code.
863 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
864 section_offset_type fnoffset
, section_size_type fnsize
,
865 const unsigned char* prelocs
, size_t reloc_count
,
866 unsigned char* view
, section_size_type view_size
,
867 std::string
* from
, std::string
* to
) const;
869 // Return the size of the GOT section.
873 gold_assert(this->got_
!= NULL
);
874 return this->got_
->data_size();
877 // Return the number of entries in the GOT.
879 got_entry_count() const
881 if (this->got_
== NULL
)
883 return this->got_size() / 8;
886 // Return the number of entries in the PLT.
888 plt_entry_count() const;
890 // Return the offset of the first non-reserved PLT entry.
892 first_plt_entry_offset() const;
894 // Return the size of each PLT entry.
896 plt_entry_size() const;
898 // Return the size of each GOT entry.
900 got_entry_size() const
903 // Create the GOT section for an incremental update.
904 Output_data_got_base
*
905 init_got_plt_for_update(Symbol_table
* symtab
,
907 unsigned int got_count
,
908 unsigned int plt_count
);
910 // Reserve a GOT entry for a local symbol, and regenerate any
911 // necessary dynamic relocations.
913 reserve_local_got_entry(unsigned int got_index
,
914 Sized_relobj
<size
, false>* obj
,
916 unsigned int got_type
);
918 // Reserve a GOT entry for a global symbol, and regenerate any
919 // necessary dynamic relocations.
921 reserve_global_got_entry(unsigned int got_index
, Symbol
* gsym
,
922 unsigned int got_type
);
924 // Register an existing PLT entry for a global symbol.
926 register_global_plt_entry(Symbol_table
*, Layout
*, unsigned int plt_index
,
929 // Force a COPY relocation for a given symbol.
931 emit_copy_reloc(Symbol_table
*, Symbol
*, Output_section
*, off_t
);
933 // Apply an incremental relocation.
935 apply_relocation(const Relocate_info
<size
, false>* relinfo
,
936 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
938 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
941 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
942 section_size_type view_size
);
944 // Add a new reloc argument, returning the index in the vector.
946 add_tlsdesc_info(Sized_relobj_file
<size
, false>* object
, unsigned int r_sym
)
948 this->tlsdesc_reloc_info_
.push_back(Tlsdesc_info(object
, r_sym
));
949 return this->tlsdesc_reloc_info_
.size() - 1;
952 Output_data_plt_x86_64
<size
>*
953 make_data_plt(Layout
* layout
,
954 Output_data_got
<64, false>* got
,
955 Output_data_got_plt_x86_64
* got_plt
,
956 Output_data_space
* got_irelative
)
958 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
);
961 Output_data_plt_x86_64
<size
>*
962 make_data_plt(Layout
* layout
,
963 Output_data_got
<64, false>* got
,
964 Output_data_got_plt_x86_64
* got_plt
,
965 Output_data_space
* got_irelative
,
966 unsigned int plt_count
)
968 return this->do_make_data_plt(layout
, got
, got_plt
, got_irelative
,
972 virtual Output_data_plt_x86_64
<size
>*
973 do_make_data_plt(Layout
* layout
,
974 Output_data_got
<64, false>* got
,
975 Output_data_got_plt_x86_64
* got_plt
,
976 Output_data_space
* got_irelative
);
978 virtual Output_data_plt_x86_64
<size
>*
979 do_make_data_plt(Layout
* layout
,
980 Output_data_got
<64, false>* got
,
981 Output_data_got_plt_x86_64
* got_plt
,
982 Output_data_space
* got_irelative
,
983 unsigned int plt_count
);
986 // The class which scans relocations.
991 : issued_non_pic_error_(false)
995 get_reference_flags(unsigned int r_type
);
998 local(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
999 Sized_relobj_file
<size
, false>* object
,
1000 unsigned int data_shndx
,
1001 Output_section
* output_section
,
1002 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
1003 const elfcpp::Sym
<size
, false>& lsym
,
1007 global(Symbol_table
* symtab
, Layout
* layout
, Target_x86_64
* target
,
1008 Sized_relobj_file
<size
, false>* object
,
1009 unsigned int data_shndx
,
1010 Output_section
* output_section
,
1011 const elfcpp::Rela
<size
, false>& reloc
, unsigned int r_type
,
1015 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
1016 Target_x86_64
* target
,
1017 Sized_relobj_file
<size
, false>* object
,
1018 unsigned int data_shndx
,
1019 Output_section
* output_section
,
1020 const elfcpp::Rela
<size
, false>& reloc
,
1021 unsigned int r_type
,
1022 const elfcpp::Sym
<size
, false>& lsym
);
1025 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
1026 Target_x86_64
* target
,
1027 Sized_relobj_file
<size
, false>* object
,
1028 unsigned int data_shndx
,
1029 Output_section
* output_section
,
1030 const elfcpp::Rela
<size
, false>& reloc
,
1031 unsigned int r_type
,
1036 unsupported_reloc_local(Sized_relobj_file
<size
, false>*,
1037 unsigned int r_type
);
1040 unsupported_reloc_global(Sized_relobj_file
<size
, false>*,
1041 unsigned int r_type
, Symbol
*);
1044 check_non_pic(Relobj
*, unsigned int r_type
, Symbol
*);
1047 possible_function_pointer_reloc(Sized_relobj_file
<size
, false>* src_obj
,
1048 unsigned int src_indx
,
1049 unsigned int r_offset
,
1050 unsigned int r_type
);
1053 reloc_needs_plt_for_ifunc(Sized_relobj_file
<size
, false>*,
1054 unsigned int r_type
);
1056 // Whether we have issued an error about a non-PIC compilation.
1057 bool issued_non_pic_error_
;
1060 // The class which implements relocation.
1065 : skip_call_tls_get_addr_(false)
1070 if (this->skip_call_tls_get_addr_
)
1072 // FIXME: This needs to specify the location somehow.
1073 gold_error(_("missing expected TLS relocation"));
1077 // Do a relocation. Return false if the caller should not issue
1078 // any warnings about this relocation.
1080 relocate(const Relocate_info
<size
, false>*, unsigned int,
1081 Target_x86_64
*, Output_section
*, size_t, const unsigned char*,
1082 const Sized_symbol
<size
>*, const Symbol_value
<size
>*,
1083 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1087 // Do a TLS relocation.
1089 relocate_tls(const Relocate_info
<size
, false>*, Target_x86_64
*,
1090 size_t relnum
, const elfcpp::Rela
<size
, false>&,
1091 unsigned int r_type
, const Sized_symbol
<size
>*,
1092 const Symbol_value
<size
>*,
1093 unsigned char*, typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1096 // Do a TLS General-Dynamic to Initial-Exec transition.
1098 tls_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
1099 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1100 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1101 unsigned char* view
,
1102 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1103 section_size_type view_size
);
1105 // Do a TLS General-Dynamic to Local-Exec transition.
1107 tls_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1108 Output_segment
* tls_segment
,
1109 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1110 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1111 unsigned char* view
,
1112 section_size_type view_size
);
1114 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
1116 tls_desc_gd_to_ie(const Relocate_info
<size
, false>*, size_t relnum
,
1117 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1118 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1119 unsigned char* view
,
1120 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
1121 section_size_type view_size
);
1123 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1125 tls_desc_gd_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1126 Output_segment
* tls_segment
,
1127 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1128 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1129 unsigned char* view
,
1130 section_size_type view_size
);
1132 // Do a TLS Local-Dynamic to Local-Exec transition.
1134 tls_ld_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1135 Output_segment
* tls_segment
,
1136 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1137 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1138 unsigned char* view
,
1139 section_size_type view_size
);
1141 // Do a TLS Initial-Exec to Local-Exec transition.
1143 tls_ie_to_le(const Relocate_info
<size
, false>*, size_t relnum
,
1144 Output_segment
* tls_segment
,
1145 const elfcpp::Rela
<size
, false>&, unsigned int r_type
,
1146 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1147 unsigned char* view
,
1148 section_size_type view_size
);
1150 // This is set if we should skip the next reloc, which should be a
1151 // PLT32 reloc against ___tls_get_addr.
1152 bool skip_call_tls_get_addr_
;
1155 // Check if relocation against this symbol is a candidate for
1157 // mov foo@GOTPCREL(%rip), %reg
1158 // to lea foo(%rip), %reg.
1159 template<class View_type
>
1161 can_convert_mov_to_lea(const Symbol
* gsym
, unsigned int r_type
,
1162 size_t r_offset
, View_type
* view
)
1164 gold_assert(gsym
!= NULL
);
1165 // We cannot do the conversion unless it's one of these relocations.
1166 if (r_type
!= elfcpp::R_X86_64_GOTPCREL
1167 && r_type
!= elfcpp::R_X86_64_GOTPCRELX
1168 && r_type
!= elfcpp::R_X86_64_REX_GOTPCRELX
)
1170 // We cannot convert references to IFUNC symbols, or to symbols that
1171 // are not local to the current module.
1172 // We can't do predefined symbols because they may become undefined
1173 // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1174 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1175 || gsym
->is_undefined()
1176 || gsym
->is_predefined()
1177 || gsym
->is_from_dynobj()
1178 || gsym
->is_preemptible())
1180 // If we are building a shared object and the symbol is protected, we may
1181 // need to go through the GOT.
1182 if (parameters
->options().shared()
1183 && gsym
->visibility() == elfcpp::STV_PROTECTED
)
1185 // We cannot convert references to the _DYNAMIC symbol.
1186 if (strcmp(gsym
->name(), "_DYNAMIC") == 0)
1188 // Check for a MOV opcode.
1189 return (*view
)[r_offset
- 2] == 0x8b;
1193 // callq *foo@GOTPCRELX(%rip) to
1195 // and jmpq *foo@GOTPCRELX(%rip) to
1198 template<class View_type
>
1200 can_convert_callq_to_direct(const Symbol
* gsym
, unsigned int r_type
,
1201 size_t r_offset
, View_type
* view
)
1203 gold_assert(gsym
!= NULL
);
1204 // We cannot do the conversion unless it's a GOTPCRELX relocation.
1205 if (r_type
!= elfcpp::R_X86_64_GOTPCRELX
)
1207 // We cannot convert references to IFUNC symbols, or to symbols that
1208 // are not local to the current module.
1209 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1210 || gsym
->is_undefined ()
1211 || gsym
->is_from_dynobj()
1212 || gsym
->is_preemptible())
1214 // Check for a CALLQ or JMPQ opcode.
1215 return ((*view
)[r_offset
- 2] == 0xff
1216 && ((*view
)[r_offset
- 1] == 0x15
1217 || (*view
)[r_offset
- 1] == 0x25));
1220 // Adjust TLS relocation type based on the options and whether this
1221 // is a local symbol.
1222 static tls::Tls_optimization
1223 optimize_tls_reloc(bool is_final
, int r_type
);
1225 // Get the GOT section, creating it if necessary.
1226 Output_data_got
<64, false>*
1227 got_section(Symbol_table
*, Layout
*);
1229 // Get the GOT PLT section.
1230 Output_data_got_plt_x86_64
*
1231 got_plt_section() const
1233 gold_assert(this->got_plt_
!= NULL
);
1234 return this->got_plt_
;
1237 // Get the GOT section for TLSDESC entries.
1238 Output_data_got
<64, false>*
1239 got_tlsdesc_section() const
1241 gold_assert(this->got_tlsdesc_
!= NULL
);
1242 return this->got_tlsdesc_
;
1245 // Create the PLT section.
1247 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
1249 // Create a PLT entry for a global symbol.
1251 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
1253 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1255 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
1256 Sized_relobj_file
<size
, false>* relobj
,
1257 unsigned int local_sym_index
);
1259 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1261 define_tls_base_symbol(Symbol_table
*, Layout
*);
1263 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1265 reserve_tlsdesc_entries(Symbol_table
* symtab
, Layout
* layout
);
1267 // Create a GOT entry for the TLS module index.
1269 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1270 Sized_relobj_file
<size
, false>* object
);
1272 // Get the PLT section.
1273 Output_data_plt_x86_64
<size
>*
1276 gold_assert(this->plt_
!= NULL
);
1280 // Get the dynamic reloc section, creating it if necessary.
1282 rela_dyn_section(Layout
*);
1284 // Get the section to use for TLSDESC relocations.
1286 rela_tlsdesc_section(Layout
*) const;
1288 // Get the section to use for IRELATIVE relocations.
1290 rela_irelative_section(Layout
*);
1292 // Add a potential copy relocation.
1294 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
1295 Sized_relobj_file
<size
, false>* object
,
1296 unsigned int shndx
, Output_section
* output_section
,
1297 Symbol
* sym
, const elfcpp::Rela
<size
, false>& reloc
)
1299 unsigned int r_type
= elfcpp::elf_r_type
<size
>(reloc
.get_r_info());
1300 this->copy_relocs_
.copy_reloc(symtab
, layout
,
1301 symtab
->get_sized_symbol
<size
>(sym
),
1302 object
, shndx
, output_section
,
1303 r_type
, reloc
.get_r_offset(),
1304 reloc
.get_r_addend(),
1305 this->rela_dyn_section(layout
));
1308 // Record a target-specific program property in the .note.gnu.property
1311 record_gnu_property(unsigned int, unsigned int, size_t,
1312 const unsigned char*, const Object
*);
1314 // Merge the target-specific program properties from the current object.
1316 merge_gnu_properties(const Object
*);
1318 // Finalize the target-specific program properties and add them back to
1321 do_finalize_gnu_properties(Layout
*) const;
1323 // Information about this specific target which we pass to the
1324 // general Target structure.
1325 static const Target::Target_info x86_64_info
;
1327 // The types of GOT entries needed for this platform.
1328 // These values are exposed to the ABI in an incremental link.
1329 // Do not renumber existing values without changing the version
1330 // number of the .gnu_incremental_inputs section.
1333 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
1334 GOT_TYPE_TLS_OFFSET
= 1, // GOT entry for TLS offset
1335 GOT_TYPE_TLS_PAIR
= 2, // GOT entry for TLS module/offset pair
1336 GOT_TYPE_TLS_DESC
= 3 // GOT entry for TLS_DESC pair
1339 // This type is used as the argument to the target specific
1340 // relocation routines. The only target specific reloc is
1341 // R_X86_64_TLSDESC against a local symbol.
1344 Tlsdesc_info(Sized_relobj_file
<size
, false>* a_object
, unsigned int a_r_sym
)
1345 : object(a_object
), r_sym(a_r_sym
)
1348 // The object in which the local symbol is defined.
1349 Sized_relobj_file
<size
, false>* object
;
1350 // The local symbol index in the object.
1355 Output_data_got
<64, false>* got_
;
1357 Output_data_plt_x86_64
<size
>* plt_
;
1358 // The GOT PLT section.
1359 Output_data_got_plt_x86_64
* got_plt_
;
1360 // The GOT section for IRELATIVE relocations.
1361 Output_data_space
* got_irelative_
;
1362 // The GOT section for TLSDESC relocations.
1363 Output_data_got
<64, false>* got_tlsdesc_
;
1364 // The _GLOBAL_OFFSET_TABLE_ symbol.
1365 Symbol
* global_offset_table_
;
1366 // The dynamic reloc section.
1367 Reloc_section
* rela_dyn_
;
1368 // The section to use for IRELATIVE relocs.
1369 Reloc_section
* rela_irelative_
;
1370 // Relocs saved to avoid a COPY reloc.
1371 Copy_relocs
<elfcpp::SHT_RELA
, size
, false> copy_relocs_
;
1372 // Offset of the GOT entry for the TLS module index.
1373 unsigned int got_mod_index_offset_
;
1374 // We handle R_X86_64_TLSDESC against a local symbol as a target
1375 // specific relocation. Here we store the object and local symbol
1376 // index for the relocation.
1377 std::vector
<Tlsdesc_info
> tlsdesc_reloc_info_
;
1378 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1379 bool tls_base_symbol_defined_
;
1380 // Target-specific program properties, from .note.gnu.property section.
1381 // Each bit represents a specific feature.
1382 uint32_t isa_1_used_
;
1383 uint32_t isa_1_needed_
;
1384 uint32_t feature_1_
;
1385 // Target-specific properties from the current object.
1386 // These bits get ORed into ISA_1_USED_ after all properties for the object
1387 // have been processed. But if either is all zeroes (as when the property
1388 // is absent from an object), the result should be all zeroes.
1389 // (See PR ld/23486.)
1390 uint32_t object_isa_1_used_
;
1391 // These bits get ANDed into FEATURE_1_ after all properties for the object
1392 // have been processed.
1393 uint32_t object_feature_1_
;
1394 // Whether we have seen our first object, for use in initializing FEATURE_1_.
1395 bool seen_first_object_
;
1399 const Target::Target_info Target_x86_64
<64>::x86_64_info
=
1402 false, // is_big_endian
1403 elfcpp::EM_X86_64
, // machine_code
1404 false, // has_make_symbol
1405 false, // has_resolve
1406 true, // has_code_fill
1407 true, // is_default_stack_executable
1408 true, // can_icf_inline_merge_sections
1410 "/lib/ld64.so.1", // program interpreter
1411 0x400000, // default_text_segment_address
1412 0x1000, // abi_pagesize (overridable by -z max-page-size)
1413 0x1000, // common_pagesize (overridable by -z common-page-size)
1414 false, // isolate_execinstr
1416 elfcpp::SHN_UNDEF
, // small_common_shndx
1417 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1418 0, // small_common_section_flags
1419 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1420 NULL
, // attributes_section
1421 NULL
, // attributes_vendor
1422 "_start", // entry_symbol_name
1423 32, // hash_entry_size
1424 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
1428 const Target::Target_info Target_x86_64
<32>::x86_64_info
=
1431 false, // is_big_endian
1432 elfcpp::EM_X86_64
, // machine_code
1433 false, // has_make_symbol
1434 false, // has_resolve
1435 true, // has_code_fill
1436 true, // is_default_stack_executable
1437 true, // can_icf_inline_merge_sections
1439 "/libx32/ldx32.so.1", // program interpreter
1440 0x400000, // default_text_segment_address
1441 0x1000, // abi_pagesize (overridable by -z max-page-size)
1442 0x1000, // common_pagesize (overridable by -z common-page-size)
1443 false, // isolate_execinstr
1445 elfcpp::SHN_UNDEF
, // small_common_shndx
1446 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
1447 0, // small_common_section_flags
1448 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
1449 NULL
, // attributes_section
1450 NULL
, // attributes_vendor
1451 "_start", // entry_symbol_name
1452 32, // hash_entry_size
1453 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
1456 // This is called when a new output section is created. This is where
1457 // we handle the SHF_X86_64_LARGE.
1461 Target_x86_64
<size
>::do_new_output_section(Output_section
* os
) const
1463 if ((os
->flags() & elfcpp::SHF_X86_64_LARGE
) != 0)
1464 os
->set_is_large_section();
1467 // Get the GOT section, creating it if necessary.
1470 Output_data_got
<64, false>*
1471 Target_x86_64
<size
>::got_section(Symbol_table
* symtab
, Layout
* layout
)
1473 if (this->got_
== NULL
)
1475 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
1477 // When using -z now, we can treat .got.plt as a relro section.
1478 // Without -z now, it is modified after program startup by lazy
1480 bool is_got_plt_relro
= parameters
->options().now();
1481 Output_section_order got_order
= (is_got_plt_relro
1483 : ORDER_RELRO_LAST
);
1484 Output_section_order got_plt_order
= (is_got_plt_relro
1486 : ORDER_NON_RELRO_FIRST
);
1488 this->got_
= new Output_data_got
<64, false>();
1490 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1492 | elfcpp::SHF_WRITE
),
1493 this->got_
, got_order
, true);
1495 this->got_plt_
= new Output_data_got_plt_x86_64(layout
);
1496 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1498 | elfcpp::SHF_WRITE
),
1499 this->got_plt_
, got_plt_order
,
1502 // The first three entries are reserved.
1503 this->got_plt_
->set_current_data_size(3 * 8);
1505 if (!is_got_plt_relro
)
1507 // Those bytes can go into the relro segment.
1508 layout
->increase_relro(3 * 8);
1511 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1512 this->global_offset_table_
=
1513 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1514 Symbol_table::PREDEFINED
,
1516 0, 0, elfcpp::STT_OBJECT
,
1518 elfcpp::STV_HIDDEN
, 0,
1521 // If there are any IRELATIVE relocations, they get GOT entries
1522 // in .got.plt after the jump slot entries.
1523 this->got_irelative_
= new Output_data_space(8, "** GOT IRELATIVE PLT");
1524 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1526 | elfcpp::SHF_WRITE
),
1527 this->got_irelative_
,
1528 got_plt_order
, is_got_plt_relro
);
1530 // If there are any TLSDESC relocations, they get GOT entries in
1531 // .got.plt after the jump slot and IRELATIVE entries.
1532 this->got_tlsdesc_
= new Output_data_got
<64, false>();
1533 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
1535 | elfcpp::SHF_WRITE
),
1537 got_plt_order
, is_got_plt_relro
);
1543 // Get the dynamic reloc section, creating it if necessary.
1546 typename Target_x86_64
<size
>::Reloc_section
*
1547 Target_x86_64
<size
>::rela_dyn_section(Layout
* layout
)
1549 if (this->rela_dyn_
== NULL
)
1551 gold_assert(layout
!= NULL
);
1552 this->rela_dyn_
= new Reloc_section(parameters
->options().combreloc());
1553 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1554 elfcpp::SHF_ALLOC
, this->rela_dyn_
,
1555 ORDER_DYNAMIC_RELOCS
, false);
1557 return this->rela_dyn_
;
1560 // Get the section to use for IRELATIVE relocs, creating it if
1561 // necessary. These go in .rela.dyn, but only after all other dynamic
1562 // relocations. They need to follow the other dynamic relocations so
1563 // that they can refer to global variables initialized by those
1567 typename Target_x86_64
<size
>::Reloc_section
*
1568 Target_x86_64
<size
>::rela_irelative_section(Layout
* layout
)
1570 if (this->rela_irelative_
== NULL
)
1572 // Make sure we have already created the dynamic reloc section.
1573 this->rela_dyn_section(layout
);
1574 this->rela_irelative_
= new Reloc_section(false);
1575 layout
->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA
,
1576 elfcpp::SHF_ALLOC
, this->rela_irelative_
,
1577 ORDER_DYNAMIC_RELOCS
, false);
1578 gold_assert(this->rela_dyn_
->output_section()
1579 == this->rela_irelative_
->output_section());
1581 return this->rela_irelative_
;
1584 // Record a target-specific program property from the .note.gnu.property
1588 Target_x86_64
<size
>::record_gnu_property(
1589 unsigned int, unsigned int pr_type
,
1590 size_t pr_datasz
, const unsigned char* pr_data
,
1591 const Object
* object
)
1597 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED
:
1598 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED
:
1599 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND
:
1602 gold_warning(_("%s: corrupt .note.gnu.property section "
1603 "(pr_datasz for property %d is not 4)"),
1604 object
->name().c_str(), pr_type
);
1607 val
= elfcpp::Swap
<32, false>::readval(pr_data
);
1610 gold_warning(_("%s: unknown program property type 0x%x "
1611 "in .note.gnu.property section"),
1612 object
->name().c_str(), pr_type
);
1618 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED
:
1619 this->object_isa_1_used_
|= val
;
1621 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED
:
1622 this->isa_1_needed_
|= val
;
1624 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND
:
1625 // If we see multiple feature props in one object, OR them together.
1626 this->object_feature_1_
|= val
;
1631 // Merge the target-specific program properties from the current object.
1634 Target_x86_64
<size
>::merge_gnu_properties(const Object
*)
1636 if (this->seen_first_object_
)
1638 // If any object is missing the ISA_1_USED property, we must omit
1639 // it from the output file.
1640 if (this->object_isa_1_used_
== 0)
1641 this->isa_1_used_
= 0;
1642 else if (this->isa_1_used_
!= 0)
1643 this->isa_1_used_
|= this->object_isa_1_used_
;
1644 this->feature_1_
&= this->object_feature_1_
;
1648 this->isa_1_used_
= this->object_isa_1_used_
;
1649 this->feature_1_
= this->object_feature_1_
;
1650 this->seen_first_object_
= true;
1652 this->object_isa_1_used_
= 0;
1653 this->object_feature_1_
= 0;
1657 add_property(Layout
* layout
, unsigned int pr_type
, uint32_t val
)
1659 unsigned char buf
[4];
1660 elfcpp::Swap
<32, false>::writeval(buf
, val
);
1661 layout
->add_gnu_property(elfcpp::NT_GNU_PROPERTY_TYPE_0
, pr_type
, 4, buf
);
1664 // Finalize the target-specific program properties and add them back to
1668 Target_x86_64
<size
>::do_finalize_gnu_properties(Layout
* layout
) const
1670 if (this->isa_1_used_
!= 0)
1671 add_property(layout
, elfcpp::GNU_PROPERTY_X86_ISA_1_USED
,
1673 if (this->isa_1_needed_
!= 0)
1674 add_property(layout
, elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED
,
1675 this->isa_1_needed_
);
1676 if (this->feature_1_
!= 0)
1677 add_property(layout
, elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND
,
1681 // Write the first three reserved words of the .got.plt section.
1682 // The remainder of the section is written while writing the PLT
1683 // in Output_data_plt_i386::do_write.
1686 Output_data_got_plt_x86_64::do_write(Output_file
* of
)
1688 // The first entry in the GOT is the address of the .dynamic section
1689 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1690 // We saved space for them when we created the section in
1691 // Target_x86_64::got_section.
1692 const off_t got_file_offset
= this->offset();
1693 gold_assert(this->data_size() >= 24);
1694 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 24);
1695 Output_section
* dynamic
= this->layout_
->dynamic_section();
1696 uint64_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1697 elfcpp::Swap
<64, false>::writeval(got_view
, dynamic_addr
);
1698 memset(got_view
+ 8, 0, 16);
1699 of
->write_output_view(got_file_offset
, 24, got_view
);
1702 // Initialize the PLT section.
1706 Output_data_plt_x86_64
<size
>::init(Layout
* layout
)
1708 this->rel_
= new Reloc_section(false);
1709 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1710 elfcpp::SHF_ALLOC
, this->rel_
,
1711 ORDER_DYNAMIC_PLT_RELOCS
, false);
1716 Output_data_plt_x86_64
<size
>::do_adjust_output_section(Output_section
* os
)
1718 os
->set_entsize(this->get_plt_entry_size());
1721 // Add an entry to the PLT.
1725 Output_data_plt_x86_64
<size
>::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1728 gold_assert(!gsym
->has_plt_offset());
1730 unsigned int plt_index
;
1732 section_offset_type got_offset
;
1734 unsigned int* pcount
;
1735 unsigned int offset
;
1736 unsigned int reserved
;
1737 Output_section_data_build
* got
;
1738 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1739 && gsym
->can_use_relative_reloc(false))
1741 pcount
= &this->irelative_count_
;
1744 got
= this->got_irelative_
;
1748 pcount
= &this->count_
;
1751 got
= this->got_plt_
;
1754 if (!this->is_data_size_valid())
1756 // Note that when setting the PLT offset for a non-IRELATIVE
1757 // entry we skip the initial reserved PLT entry.
1758 plt_index
= *pcount
+ offset
;
1759 plt_offset
= plt_index
* this->get_plt_entry_size();
1763 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1764 gold_assert(got_offset
== got
->current_data_size());
1766 // Every PLT entry needs a GOT entry which points back to the PLT
1767 // entry (this will be changed by the dynamic linker, normally
1768 // lazily when the function is called).
1769 got
->set_current_data_size(got_offset
+ 8);
1773 // FIXME: This is probably not correct for IRELATIVE relocs.
1775 // For incremental updates, find an available slot.
1776 plt_offset
= this->free_list_
.allocate(this->get_plt_entry_size(),
1777 this->get_plt_entry_size(), 0);
1778 if (plt_offset
== -1)
1779 gold_fallback(_("out of patch space (PLT);"
1780 " relink with --incremental-full"));
1782 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1783 // can be calculated from the PLT index, adjusting for the three
1784 // reserved entries at the beginning of the GOT.
1785 plt_index
= plt_offset
/ this->get_plt_entry_size() - 1;
1786 got_offset
= (plt_index
- offset
+ reserved
) * 8;
1789 gsym
->set_plt_offset(plt_offset
);
1791 // Every PLT entry needs a reloc.
1792 this->add_relocation(symtab
, layout
, gsym
, got_offset
);
1794 // Note that we don't need to save the symbol. The contents of the
1795 // PLT are independent of which symbols are used. The symbols only
1796 // appear in the relocations.
1799 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1804 Output_data_plt_x86_64
<size
>::add_local_ifunc_entry(
1805 Symbol_table
* symtab
,
1807 Sized_relobj_file
<size
, false>* relobj
,
1808 unsigned int local_sym_index
)
1810 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1811 ++this->irelative_count_
;
1813 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1815 // Every PLT entry needs a GOT entry which points back to the PLT
1817 this->got_irelative_
->set_current_data_size(got_offset
+ 8);
1819 // Every PLT entry needs a reloc.
1820 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1821 rela
->add_symbolless_local_addend(relobj
, local_sym_index
,
1822 elfcpp::R_X86_64_IRELATIVE
,
1823 this->got_irelative_
, got_offset
, 0);
1828 // Add the relocation for a PLT entry.
1832 Output_data_plt_x86_64
<size
>::add_relocation(Symbol_table
* symtab
,
1835 unsigned int got_offset
)
1837 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1838 && gsym
->can_use_relative_reloc(false))
1840 Reloc_section
* rela
= this->rela_irelative(symtab
, layout
);
1841 rela
->add_symbolless_global_addend(gsym
, elfcpp::R_X86_64_IRELATIVE
,
1842 this->got_irelative_
, got_offset
, 0);
1846 gsym
->set_needs_dynsym_entry();
1847 this->rel_
->add_global(gsym
, elfcpp::R_X86_64_JUMP_SLOT
, this->got_plt_
,
1852 // Return where the TLSDESC relocations should go, creating it if
1853 // necessary. These follow the JUMP_SLOT relocations.
1856 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1857 Output_data_plt_x86_64
<size
>::rela_tlsdesc(Layout
* layout
)
1859 if (this->tlsdesc_rel_
== NULL
)
1861 this->tlsdesc_rel_
= new Reloc_section(false);
1862 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1863 elfcpp::SHF_ALLOC
, this->tlsdesc_rel_
,
1864 ORDER_DYNAMIC_PLT_RELOCS
, false);
1865 gold_assert(this->tlsdesc_rel_
->output_section()
1866 == this->rel_
->output_section());
1868 return this->tlsdesc_rel_
;
1871 // Return where the IRELATIVE relocations should go in the PLT. These
1872 // follow the JUMP_SLOT and the TLSDESC relocations.
1875 typename Output_data_plt_x86_64
<size
>::Reloc_section
*
1876 Output_data_plt_x86_64
<size
>::rela_irelative(Symbol_table
* symtab
,
1879 if (this->irelative_rel_
== NULL
)
1881 // Make sure we have a place for the TLSDESC relocations, in
1882 // case we see any later on.
1883 this->rela_tlsdesc(layout
);
1884 this->irelative_rel_
= new Reloc_section(false);
1885 layout
->add_output_section_data(".rela.plt", elfcpp::SHT_RELA
,
1886 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1887 ORDER_DYNAMIC_PLT_RELOCS
, false);
1888 gold_assert(this->irelative_rel_
->output_section()
1889 == this->rel_
->output_section());
1891 if (parameters
->doing_static_link())
1893 // A statically linked executable will only have a .rela.plt
1894 // section to hold R_X86_64_IRELATIVE relocs for
1895 // STT_GNU_IFUNC symbols. The library will use these
1896 // symbols to locate the IRELATIVE relocs at program startup
1898 symtab
->define_in_output_data("__rela_iplt_start", NULL
,
1899 Symbol_table::PREDEFINED
,
1900 this->irelative_rel_
, 0, 0,
1901 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1902 elfcpp::STV_HIDDEN
, 0, false, true);
1903 symtab
->define_in_output_data("__rela_iplt_end", NULL
,
1904 Symbol_table::PREDEFINED
,
1905 this->irelative_rel_
, 0, 0,
1906 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1907 elfcpp::STV_HIDDEN
, 0, true, true);
1910 return this->irelative_rel_
;
1913 // Return the PLT address to use for a global symbol.
1917 Output_data_plt_x86_64
<size
>::do_address_for_global(const Symbol
* gsym
)
1919 uint64_t offset
= 0;
1920 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1921 && gsym
->can_use_relative_reloc(false))
1922 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1923 return this->address() + offset
+ gsym
->plt_offset();
1926 // Return the PLT address to use for a local symbol. These are always
1927 // IRELATIVE relocs.
1931 Output_data_plt_x86_64
<size
>::do_address_for_local(const Relobj
* object
,
1934 return (this->address()
1935 + (this->count_
+ 1) * this->get_plt_entry_size()
1936 + object
->local_plt_offset(r_sym
));
1939 // Set the final size.
1942 Output_data_plt_x86_64
<size
>::set_final_data_size()
1944 // Number of regular and IFUNC PLT entries, plus the first entry.
1945 unsigned int count
= this->count_
+ this->irelative_count_
+ 1;
1946 // Count the TLSDESC entry, if present.
1947 if (this->has_tlsdesc_entry())
1949 this->set_data_size(count
* this->get_plt_entry_size());
1952 // The first entry in the PLT for an executable.
1956 Output_data_plt_x86_64_standard
<size
>::first_plt_entry
[plt_entry_size
] =
1958 // From AMD64 ABI Draft 0.98, page 76
1959 0xff, 0x35, // pushq contents of memory address
1960 0, 0, 0, 0, // replaced with address of .got + 8
1961 0xff, 0x25, // jmp indirect
1962 0, 0, 0, 0, // replaced with address of .got + 16
1963 0x90, 0x90, 0x90, 0x90 // noop (x4)
1968 Output_data_plt_x86_64_standard
<size
>::do_fill_first_plt_entry(
1970 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
1971 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
1973 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1974 // We do a jmp relative to the PC at the end of this instruction.
1975 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1977 - (plt_address
+ 6)));
1978 elfcpp::Swap
<32, false>::writeval(pov
+ 8,
1980 - (plt_address
+ 12)));
1983 // Subsequent entries in the PLT for an executable.
1987 Output_data_plt_x86_64_standard
<size
>::plt_entry
[plt_entry_size
] =
1989 // From AMD64 ABI Draft 0.98, page 76
1990 0xff, 0x25, // jmpq indirect
1991 0, 0, 0, 0, // replaced with address of symbol in .got
1992 0x68, // pushq immediate
1993 0, 0, 0, 0, // replaced with offset into relocation table
1994 0xe9, // jmpq relative
1995 0, 0, 0, 0 // replaced with offset to start of .plt
2000 Output_data_plt_x86_64_standard
<size
>::do_fill_plt_entry(
2002 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2003 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2004 unsigned int got_offset
,
2005 unsigned int plt_offset
,
2006 unsigned int plt_index
)
2008 // Check PC-relative offset overflow in PLT entry.
2009 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
2010 - (plt_address
+ plt_offset
+ 6));
2011 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
2012 gold_error(_("PC-relative offset overflow in PLT entry %d"),
2015 memcpy(pov
, plt_entry
, plt_entry_size
);
2016 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2017 plt_got_pcrel_offset
);
2019 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_index
);
2020 elfcpp::Swap
<32, false>::writeval(pov
+ 12,
2021 - (plt_offset
+ plt_entry_size
));
2026 // The reserved TLSDESC entry in the PLT for an executable.
2030 Output_data_plt_x86_64_standard
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
2032 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2033 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2034 0xff, 0x35, // pushq x(%rip)
2035 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2036 0xff, 0x25, // jmpq *y(%rip)
2037 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2044 Output_data_plt_x86_64_standard
<size
>::do_fill_tlsdesc_entry(
2046 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2047 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2048 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
2049 unsigned int tlsdesc_got_offset
,
2050 unsigned int plt_offset
)
2052 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
2053 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2055 - (plt_address
+ plt_offset
2057 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 8,
2059 + tlsdesc_got_offset
2060 - (plt_address
+ plt_offset
2064 // Return the APLT address to use for a global symbol (for -z bndplt).
2067 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol
* gsym
)
2069 uint64_t offset
= this->aplt_offset_
;
2070 // Convert the PLT offset into an APLT offset.
2071 unsigned int plt_offset
= gsym
->plt_offset();
2072 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2073 && gsym
->can_use_relative_reloc(false))
2074 offset
+= this->regular_count() * aplt_entry_size
;
2076 plt_offset
-= plt_entry_size
;
2077 plt_offset
= plt_offset
/ (plt_entry_size
/ aplt_entry_size
);
2078 return this->address() + offset
+ plt_offset
;
2081 // Return the PLT address to use for a local symbol. These are always
2082 // IRELATIVE relocs.
2085 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj
* object
,
2088 // Convert the PLT offset into an APLT offset.
2089 const Sized_relobj_file
<64, false>* sized_relobj
=
2090 static_cast<const Sized_relobj_file
<64, false>*>(object
);
2091 const Symbol_value
<64>* psymval
= sized_relobj
->local_symbol(r_sym
);
2092 unsigned int plt_offset
= ((object
->local_plt_offset(r_sym
)
2093 - (psymval
->is_ifunc_symbol()
2094 ? 0 : plt_entry_size
))
2095 / (plt_entry_size
/ aplt_entry_size
));
2096 return (this->address()
2097 + this->aplt_offset_
2098 + this->regular_count() * aplt_entry_size
2102 // Set the final size.
2104 Output_data_plt_x86_64_bnd::set_final_data_size()
2106 // Number of regular and IFUNC PLT entries.
2107 unsigned int count
= this->entry_count();
2108 // Count the first entry and the TLSDESC entry, if present.
2109 unsigned int extra
= this->has_tlsdesc_entry() ? 2 : 1;
2110 unsigned int plt_size
= (count
+ extra
) * plt_entry_size
;
2111 // Offset of the APLT.
2112 this->aplt_offset_
= plt_size
;
2113 // Size of the APLT.
2114 plt_size
+= count
* aplt_entry_size
;
2115 this->set_data_size(plt_size
);
2118 // The first entry in the BND PLT.
2121 Output_data_plt_x86_64_bnd::first_plt_entry
[plt_entry_size
] =
2123 // From AMD64 ABI Draft 0.98, page 76
2124 0xff, 0x35, // pushq contents of memory address
2125 0, 0, 0, 0, // replaced with address of .got + 8
2126 0xf2, 0xff, 0x25, // bnd jmp indirect
2127 0, 0, 0, 0, // replaced with address of .got + 16
2128 0x0f, 0x1f, 0x00 // nop
2132 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
2134 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
2135 elfcpp::Elf_types
<64>::Elf_Addr plt_address
)
2137 memcpy(pov
, first_plt_entry
, plt_entry_size
);
2138 // We do a jmp relative to the PC at the end of this instruction.
2139 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2141 - (plt_address
+ 6)));
2142 elfcpp::Swap
<32, false>::writeval(pov
+ 9,
2144 - (plt_address
+ 13)));
2147 // Subsequent entries in the BND PLT.
2150 Output_data_plt_x86_64_bnd::plt_entry
[plt_entry_size
] =
2152 // From AMD64 ABI Draft 0.99.8, page 139
2153 0x68, // pushq immediate
2154 0, 0, 0, 0, // replaced with offset into relocation table
2155 0xf2, 0xe9, // bnd jmpq relative
2156 0, 0, 0, 0, // replaced with offset to start of .plt
2157 0x0f, 0x1f, 0x44, 0, 0 // nop
2160 // Entries in the BND Additional PLT.
2163 Output_data_plt_x86_64_bnd::aplt_entry
[aplt_entry_size
] =
2165 // From AMD64 ABI Draft 0.99.8, page 139
2166 0xf2, 0xff, 0x25, // bnd jmpq indirect
2167 0, 0, 0, 0, // replaced with address of symbol in .got
2172 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
2174 elfcpp::Elf_types
<64>::Elf_Addr
,
2175 elfcpp::Elf_types
<64>::Elf_Addr
,
2177 unsigned int plt_offset
,
2178 unsigned int plt_index
)
2180 memcpy(pov
, plt_entry
, plt_entry_size
);
2181 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 1, plt_index
);
2182 elfcpp::Swap
<32, false>::writeval(pov
+ 7, -(plt_offset
+ 11));
2187 Output_data_plt_x86_64_bnd::fill_aplt_entry(
2189 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
2190 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
2191 unsigned int got_offset
,
2192 unsigned int plt_offset
,
2193 unsigned int plt_index
)
2195 // Check PC-relative offset overflow in PLT entry.
2196 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
2197 - (plt_address
+ plt_offset
+ 7));
2198 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
2199 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2202 memcpy(pov
, aplt_entry
, aplt_entry_size
);
2203 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3, plt_got_pcrel_offset
);
2206 // The reserved TLSDESC entry in the PLT for an executable.
2209 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry
[plt_entry_size
] =
2211 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2212 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2213 0xff, 0x35, // pushq x(%rip)
2214 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2215 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2216 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2217 0x0f, 0x1f, 0 // nop
2221 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
2223 elfcpp::Elf_types
<64>::Elf_Addr got_address
,
2224 elfcpp::Elf_types
<64>::Elf_Addr plt_address
,
2225 elfcpp::Elf_types
<64>::Elf_Addr got_base
,
2226 unsigned int tlsdesc_got_offset
,
2227 unsigned int plt_offset
)
2229 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
2230 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2232 - (plt_address
+ plt_offset
2234 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
2236 + tlsdesc_got_offset
2237 - (plt_address
+ plt_offset
2241 // Return the APLT address to use for a global symbol (for IBT).
2245 Output_data_plt_x86_64_ibt
<size
>::do_address_for_global(const Symbol
* gsym
)
2247 uint64_t offset
= this->aplt_offset_
;
2248 // Convert the PLT offset into an APLT offset.
2249 unsigned int plt_offset
= gsym
->plt_offset();
2250 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2251 && gsym
->can_use_relative_reloc(false))
2252 offset
+= this->regular_count() * aplt_entry_size
;
2254 plt_offset
-= plt_entry_size
;
2255 plt_offset
= plt_offset
/ (plt_entry_size
/ aplt_entry_size
);
2256 return this->address() + offset
+ plt_offset
;
2259 // Return the PLT address to use for a local symbol. These are always
2260 // IRELATIVE relocs.
2264 Output_data_plt_x86_64_ibt
<size
>::do_address_for_local(const Relobj
* object
,
2267 // Convert the PLT offset into an APLT offset.
2268 const Sized_relobj_file
<size
, false>* sized_relobj
=
2269 static_cast<const Sized_relobj_file
<size
, false>*>(object
);
2270 const Symbol_value
<size
>* psymval
= sized_relobj
->local_symbol(r_sym
);
2271 unsigned int plt_offset
= ((object
->local_plt_offset(r_sym
)
2272 - (psymval
->is_ifunc_symbol()
2273 ? 0 : plt_entry_size
))
2274 / (plt_entry_size
/ aplt_entry_size
));
2275 return (this->address()
2276 + this->aplt_offset_
2277 + this->regular_count() * aplt_entry_size
2281 // Set the final size.
2285 Output_data_plt_x86_64_ibt
<size
>::set_final_data_size()
2287 // Number of regular and IFUNC PLT entries.
2288 unsigned int count
= this->entry_count();
2289 // Count the first entry and the TLSDESC entry, if present.
2290 unsigned int extra
= this->has_tlsdesc_entry() ? 2 : 1;
2291 unsigned int plt_size
= (count
+ extra
) * plt_entry_size
;
2292 // Offset of the APLT.
2293 this->aplt_offset_
= plt_size
;
2294 // Size of the APLT.
2295 plt_size
+= count
* aplt_entry_size
;
2296 this->set_data_size(plt_size
);
2299 // The first entry in the IBT PLT.
2303 Output_data_plt_x86_64_ibt
<32>::first_plt_entry
[plt_entry_size
] =
2305 // MPX isn't supported for x32, so we don't need the BND prefix.
2306 // From AMD64 ABI Draft 0.98, page 76
2307 0xff, 0x35, // pushq contents of memory address
2308 0, 0, 0, 0, // replaced with address of .got + 8
2309 0xff, 0x25, // jmp indirect
2310 0, 0, 0, 0, // replaced with address of .got + 16
2311 0x90, 0x90, 0x90, 0x90 // noop (x4)
2316 Output_data_plt_x86_64_ibt
<64>::first_plt_entry
[plt_entry_size
] =
2318 // Use the BND prefix so that IBT is compatible with MPX.
2319 0xff, 0x35, // pushq contents of memory address
2320 0, 0, 0, 0, // replaced with address of .got + 8
2321 0xf2, 0xff, 0x25, // bnd jmp indirect
2322 0, 0, 0, 0, // replaced with address of .got + 16
2323 0x0f, 0x1f, 0x00 // nop
2328 Output_data_plt_x86_64_ibt
<size
>::do_fill_first_plt_entry(
2330 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2331 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
2333 // Offsets to the addresses needing relocation.
2334 const unsigned int roff1
= 2;
2335 const unsigned int roff2
= (size
== 32) ? 8 : 9;
2337 memcpy(pov
, first_plt_entry
, plt_entry_size
);
2338 // We do a jmp relative to the PC at the end of this instruction.
2339 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ roff1
,
2341 - (plt_address
+ roff1
+ 4)));
2342 elfcpp::Swap
<32, false>::writeval(pov
+ roff2
,
2344 - (plt_address
+ roff2
+ 4)));
2347 // Subsequent entries in the IBT PLT.
2351 Output_data_plt_x86_64_ibt
<32>::plt_entry
[plt_entry_size
] =
2353 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2354 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2355 0x68, // pushq immediate
2356 0, 0, 0, 0, // replaced with offset into relocation table
2357 0xe9, // jmpq relative
2358 0, 0, 0, 0, // replaced with offset to start of .plt
2364 Output_data_plt_x86_64_ibt
<64>::plt_entry
[plt_entry_size
] =
2366 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2367 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2368 0x68, // pushq immediate
2369 0, 0, 0, 0, // replaced with offset into relocation table
2370 0xf2, 0xe9, // bnd jmpq relative
2371 0, 0, 0, 0, // replaced with offset to start of .plt
2375 // Entries in the IBT Additional PLT.
2379 Output_data_plt_x86_64_ibt
<32>::aplt_entry
[aplt_entry_size
] =
2381 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2382 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2383 0xff, 0x25, // jmpq indirect
2384 0, 0, 0, 0, // replaced with address of symbol in .got
2385 0x0f, 0x1f, 0x04, 0x00, // nop
2391 Output_data_plt_x86_64_ibt
<64>::aplt_entry
[aplt_entry_size
] =
2393 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2394 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2395 0xf2, 0xff, 0x25, // bnd jmpq indirect
2396 0, 0, 0, 0, // replaced with address of symbol in .got
2397 0x0f, 0x1f, 0x04, 0x00, // nop
2403 Output_data_plt_x86_64_ibt
<size
>::do_fill_plt_entry(
2405 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
2406 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
2408 unsigned int plt_offset
,
2409 unsigned int plt_index
)
2411 // Offsets to the addresses needing relocation.
2412 const unsigned int roff1
= 5;
2413 const unsigned int roff2
= (size
== 32) ? 10 : 11;
2415 memcpy(pov
, plt_entry
, plt_entry_size
);
2416 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ roff1
, plt_index
);
2417 elfcpp::Swap
<32, false>::writeval(pov
+ roff2
, -(plt_offset
+ roff2
+ 4));
2423 Output_data_plt_x86_64_ibt
<size
>::fill_aplt_entry(
2425 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2426 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2427 unsigned int got_offset
,
2428 unsigned int plt_offset
,
2429 unsigned int plt_index
)
2431 // Offset to the address needing relocation.
2432 const unsigned int roff
= (size
== 32) ? 6 : 7;
2434 // Check PC-relative offset overflow in PLT entry.
2435 uint64_t plt_got_pcrel_offset
= (got_address
+ got_offset
2436 - (plt_address
+ plt_offset
+ roff
+ 4));
2437 if (Bits
<32>::has_overflow(plt_got_pcrel_offset
))
2438 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2441 memcpy(pov
, aplt_entry
, aplt_entry_size
);
2442 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ roff
, plt_got_pcrel_offset
);
2445 // The reserved TLSDESC entry in the IBT PLT for an executable.
2449 Output_data_plt_x86_64_ibt
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
2451 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2452 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2453 0xff, 0x35, // pushq x(%rip)
2454 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2455 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2456 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2457 0x0f, 0x1f, 0 // nop
2462 Output_data_plt_x86_64_ibt
<size
>::do_fill_tlsdesc_entry(
2464 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
2465 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
2466 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
2467 unsigned int tlsdesc_got_offset
,
2468 unsigned int plt_offset
)
2470 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
2471 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
2473 - (plt_address
+ plt_offset
2475 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
2477 + tlsdesc_got_offset
2478 - (plt_address
+ plt_offset
2482 // The .eh_frame unwind information for the PLT.
2486 Output_data_plt_x86_64
<size
>::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
2489 'z', // Augmentation: augmentation size included.
2490 'R', // Augmentation: FDE encoding included.
2491 '\0', // End of augmentation string.
2492 1, // Code alignment factor.
2493 0x78, // Data alignment factor.
2494 16, // Return address column.
2495 1, // Augmentation size.
2496 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
2497 | elfcpp::DW_EH_PE_sdata4
),
2498 elfcpp::DW_CFA_def_cfa
, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
2499 elfcpp::DW_CFA_offset
+ 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2500 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
2506 Output_data_plt_x86_64_standard
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2508 0, 0, 0, 0, // Replaced with offset to .plt.
2509 0, 0, 0, 0, // Replaced with size of .plt.
2510 0, // Augmentation size.
2511 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2512 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2513 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2514 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2515 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2516 11, // Block length.
2517 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2518 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2519 elfcpp::DW_OP_lit15
, // Push 0xf.
2520 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2521 elfcpp::DW_OP_lit11
, // Push 0xb.
2522 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 0xb)
2523 elfcpp::DW_OP_lit3
, // Push 3.
2524 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 0xb) << 3)
2525 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2526 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2532 // The .eh_frame unwind information for the BND PLT.
2534 Output_data_plt_x86_64_bnd::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2536 0, 0, 0, 0, // Replaced with offset to .plt.
2537 0, 0, 0, 0, // Replaced with size of .plt.
2538 0, // Augmentation size.
2539 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2540 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2541 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2542 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2543 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2544 11, // Block length.
2545 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2546 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2547 elfcpp::DW_OP_lit15
, // Push 0xf.
2548 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2549 elfcpp::DW_OP_lit5
, // Push 5.
2550 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 5)
2551 elfcpp::DW_OP_lit3
, // Push 3.
2552 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 5) << 3)
2553 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
2554 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2560 // The .eh_frame unwind information for the BND PLT.
2563 Output_data_plt_x86_64_ibt
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
2565 0, 0, 0, 0, // Replaced with offset to .plt.
2566 0, 0, 0, 0, // Replaced with size of .plt.
2567 0, // Augmentation size.
2568 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
2569 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
2570 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
2571 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
2572 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
2573 11, // Block length.
2574 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
2575 elfcpp::DW_OP_breg16
, 0, // Push %rip.
2576 elfcpp::DW_OP_lit15
, // Push 0xf.
2577 elfcpp::DW_OP_and
, // & (%rip & 0xf).
2578 elfcpp::DW_OP_lit9
, // Push 9.
2579 elfcpp::DW_OP_ge
, // >= ((%rip & 0xf) >= 9)
2580 elfcpp::DW_OP_lit3
, // Push 3.
2581 elfcpp::DW_OP_shl
, // << (((%rip & 0xf) >= 9) << 3)
2582 elfcpp::DW_OP_plus
, // + ((((%rip&0xf)>=9)<<3)+%rsp+8
2583 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
2589 // Write out the PLT. This uses the hand-coded instructions above,
2590 // and adjusts them as needed. This is specified by the AMD64 ABI.
2594 Output_data_plt_x86_64
<size
>::do_write(Output_file
* of
)
2596 const off_t offset
= this->offset();
2597 const section_size_type oview_size
=
2598 convert_to_section_size_type(this->data_size());
2599 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2601 const off_t got_file_offset
= this->got_plt_
->offset();
2602 gold_assert(parameters
->incremental_update()
2603 || (got_file_offset
+ this->got_plt_
->data_size()
2604 == this->got_irelative_
->offset()));
2605 const section_size_type got_size
=
2606 convert_to_section_size_type(this->got_plt_
->data_size()
2607 + this->got_irelative_
->data_size());
2608 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2611 unsigned char* pov
= oview
;
2613 // The base address of the .plt section.
2614 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
= this->address();
2615 // The base address of the .got section.
2616 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
= this->got_
->address();
2617 // The base address of the PLT portion of the .got section,
2618 // which is where the GOT pointer will point, and where the
2619 // three reserved GOT entries are located.
2620 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
2621 = this->got_plt_
->address();
2623 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2624 pov
+= this->get_plt_entry_size();
2626 // The first three entries in the GOT are reserved, and are written
2627 // by Output_data_got_plt_x86_64::do_write.
2628 unsigned char* got_pov
= got_view
+ 24;
2630 unsigned int plt_offset
= this->get_plt_entry_size();
2631 unsigned int got_offset
= 24;
2632 const unsigned int count
= this->count_
+ this->irelative_count_
;
2633 for (unsigned int plt_index
= 0;
2636 pov
+= this->get_plt_entry_size(),
2638 plt_offset
+= this->get_plt_entry_size(),
2641 // Set and adjust the PLT entry itself.
2642 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2643 got_address
, plt_address
,
2644 got_offset
, plt_offset
,
2647 // Set the entry in the GOT.
2648 elfcpp::Swap
<64, false>::writeval(got_pov
,
2649 plt_address
+ plt_offset
+ lazy_offset
);
2652 if (this->has_tlsdesc_entry())
2654 // Set and adjust the reserved TLSDESC PLT entry.
2655 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2656 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2657 tlsdesc_got_offset
, plt_offset
);
2658 pov
+= this->get_plt_entry_size();
2661 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2662 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2664 of
->write_output_view(offset
, oview_size
, oview
);
2665 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2668 // Write out the BND PLT.
2671 Output_data_plt_x86_64_bnd::do_write(Output_file
* of
)
2673 const off_t offset
= this->offset();
2674 const section_size_type oview_size
=
2675 convert_to_section_size_type(this->data_size());
2676 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2678 Output_data_got
<64, false>* got
= this->got();
2679 Output_data_got_plt_x86_64
* got_plt
= this->got_plt();
2680 Output_data_space
* got_irelative
= this->got_irelative();
2682 const off_t got_file_offset
= got_plt
->offset();
2683 gold_assert(parameters
->incremental_update()
2684 || (got_file_offset
+ got_plt
->data_size()
2685 == got_irelative
->offset()));
2686 const section_size_type got_size
=
2687 convert_to_section_size_type(got_plt
->data_size()
2688 + got_irelative
->data_size());
2689 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2692 unsigned char* pov
= oview
;
2694 // The base address of the .plt section.
2695 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
2696 // The base address of the .got section.
2697 elfcpp::Elf_types
<64>::Elf_Addr got_base
= got
->address();
2698 // The base address of the PLT portion of the .got section,
2699 // which is where the GOT pointer will point, and where the
2700 // three reserved GOT entries are located.
2701 elfcpp::Elf_types
<64>::Elf_Addr got_address
= got_plt
->address();
2703 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2704 pov
+= plt_entry_size
;
2706 // The first three entries in the GOT are reserved, and are written
2707 // by Output_data_got_plt_x86_64::do_write.
2708 unsigned char* got_pov
= got_view
+ 24;
2710 unsigned int plt_offset
= plt_entry_size
;
2711 unsigned int got_offset
= 24;
2712 const unsigned int count
= this->entry_count();
2713 for (unsigned int plt_index
= 0;
2716 pov
+= plt_entry_size
,
2718 plt_offset
+= plt_entry_size
,
2721 // Set and adjust the PLT entry itself.
2722 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2723 got_address
, plt_address
,
2724 got_offset
, plt_offset
,
2727 // Set the entry in the GOT.
2728 elfcpp::Swap
<64, false>::writeval(got_pov
,
2729 plt_address
+ plt_offset
+ lazy_offset
);
2732 if (this->has_tlsdesc_entry())
2734 // Set and adjust the reserved TLSDESC PLT entry.
2735 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2736 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2737 tlsdesc_got_offset
, plt_offset
);
2738 pov
+= this->get_plt_entry_size();
2741 // Write the additional PLT.
2743 for (unsigned int plt_index
= 0;
2746 pov
+= aplt_entry_size
,
2747 plt_offset
+= aplt_entry_size
,
2750 // Set and adjust the APLT entry.
2751 this->fill_aplt_entry(pov
, got_address
, plt_address
, got_offset
,
2752 plt_offset
, plt_index
);
2755 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2756 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2758 of
->write_output_view(offset
, oview_size
, oview
);
2759 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2762 // Write out the IBT PLT.
2766 Output_data_plt_x86_64_ibt
<size
>::do_write(Output_file
* of
)
2768 const off_t offset
= this->offset();
2769 const section_size_type oview_size
=
2770 convert_to_section_size_type(this->data_size());
2771 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2773 Output_data_got
<64, false>* got
= this->got();
2774 Output_data_got_plt_x86_64
* got_plt
= this->got_plt();
2775 Output_data_space
* got_irelative
= this->got_irelative();
2777 const off_t got_file_offset
= got_plt
->offset();
2778 gold_assert(parameters
->incremental_update()
2779 || (got_file_offset
+ got_plt
->data_size()
2780 == got_irelative
->offset()));
2781 const section_size_type got_size
=
2782 convert_to_section_size_type(got_plt
->data_size()
2783 + got_irelative
->data_size());
2784 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
2787 unsigned char* pov
= oview
;
2789 // The base address of the .plt section.
2790 elfcpp::Elf_types
<64>::Elf_Addr plt_address
= this->address();
2791 // The base address of the .got section.
2792 elfcpp::Elf_types
<64>::Elf_Addr got_base
= got
->address();
2793 // The base address of the PLT portion of the .got section,
2794 // which is where the GOT pointer will point, and where the
2795 // three reserved GOT entries are located.
2796 elfcpp::Elf_types
<64>::Elf_Addr got_address
= got_plt
->address();
2798 this->fill_first_plt_entry(pov
, got_address
, plt_address
);
2799 pov
+= plt_entry_size
;
2801 // The first three entries in the GOT are reserved, and are written
2802 // by Output_data_got_plt_x86_64::do_write.
2803 unsigned char* got_pov
= got_view
+ 24;
2805 unsigned int plt_offset
= plt_entry_size
;
2806 unsigned int got_offset
= 24;
2807 const unsigned int count
= this->entry_count();
2808 for (unsigned int plt_index
= 0;
2811 pov
+= plt_entry_size
,
2813 plt_offset
+= plt_entry_size
,
2816 // Set and adjust the PLT entry itself.
2817 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
2818 got_address
, plt_address
,
2819 got_offset
, plt_offset
,
2822 // Set the entry in the GOT.
2823 elfcpp::Swap
<64, false>::writeval(got_pov
,
2824 plt_address
+ plt_offset
+ lazy_offset
);
2827 if (this->has_tlsdesc_entry())
2829 // Set and adjust the reserved TLSDESC PLT entry.
2830 unsigned int tlsdesc_got_offset
= this->get_tlsdesc_got_offset();
2831 this->fill_tlsdesc_entry(pov
, got_address
, plt_address
, got_base
,
2832 tlsdesc_got_offset
, plt_offset
);
2833 pov
+= this->get_plt_entry_size();
2836 // Write the additional PLT.
2838 for (unsigned int plt_index
= 0;
2841 pov
+= aplt_entry_size
,
2842 plt_offset
+= aplt_entry_size
,
2845 // Set and adjust the APLT entry.
2846 this->fill_aplt_entry(pov
, got_address
, plt_address
, got_offset
,
2847 plt_offset
, plt_index
);
2850 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
2851 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
2853 of
->write_output_view(offset
, oview_size
, oview
);
2854 of
->write_output_view(got_file_offset
, got_size
, got_view
);
2857 // Create the PLT section.
2861 Target_x86_64
<size
>::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
2863 if (this->plt_
== NULL
)
2865 // Create the GOT sections first.
2866 this->got_section(symtab
, layout
);
2868 this->plt_
= this->make_data_plt(layout
, this->got_
, this->got_plt_
,
2869 this->got_irelative_
);
2871 // Add unwind information if requested.
2872 if (parameters
->options().ld_generated_unwind_info())
2873 this->plt_
->add_eh_frame(layout
);
2875 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
2877 | elfcpp::SHF_EXECINSTR
),
2878 this->plt_
, ORDER_PLT
, false);
2880 // Make the sh_info field of .rela.plt point to .plt.
2881 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
2882 rela_plt_os
->set_info_section(this->plt_
->output_section());
2887 Output_data_plt_x86_64
<32>*
2888 Target_x86_64
<32>::do_make_data_plt(Layout
* layout
,
2889 Output_data_got
<64, false>* got
,
2890 Output_data_got_plt_x86_64
* got_plt
,
2891 Output_data_space
* got_irelative
)
2893 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2894 return new Output_data_plt_x86_64_ibt
<32>(layout
, got
, got_plt
,
2896 return new Output_data_plt_x86_64_standard
<32>(layout
, got
, got_plt
,
2901 Output_data_plt_x86_64
<64>*
2902 Target_x86_64
<64>::do_make_data_plt(Layout
* layout
,
2903 Output_data_got
<64, false>* got
,
2904 Output_data_got_plt_x86_64
* got_plt
,
2905 Output_data_space
* got_irelative
)
2907 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2908 return new Output_data_plt_x86_64_ibt
<64>(layout
, got
, got_plt
,
2910 else if (parameters
->options().bndplt())
2911 return new Output_data_plt_x86_64_bnd(layout
, got
, got_plt
,
2914 return new Output_data_plt_x86_64_standard
<64>(layout
, got
, got_plt
,
2919 Output_data_plt_x86_64
<32>*
2920 Target_x86_64
<32>::do_make_data_plt(Layout
* layout
,
2921 Output_data_got
<64, false>* got
,
2922 Output_data_got_plt_x86_64
* got_plt
,
2923 Output_data_space
* got_irelative
,
2924 unsigned int plt_count
)
2926 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2927 return new Output_data_plt_x86_64_ibt
<32>(layout
, got
, got_plt
,
2928 got_irelative
, plt_count
);
2929 return new Output_data_plt_x86_64_standard
<32>(layout
, got
, got_plt
,
2930 got_irelative
, plt_count
);
2934 Output_data_plt_x86_64
<64>*
2935 Target_x86_64
<64>::do_make_data_plt(Layout
* layout
,
2936 Output_data_got
<64, false>* got
,
2937 Output_data_got_plt_x86_64
* got_plt
,
2938 Output_data_space
* got_irelative
,
2939 unsigned int plt_count
)
2941 if (this->feature_1_
& elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT
)
2942 return new Output_data_plt_x86_64_ibt
<64>(layout
, got
, got_plt
,
2943 got_irelative
, plt_count
);
2944 else if (parameters
->options().bndplt())
2945 return new Output_data_plt_x86_64_bnd(layout
, got
, got_plt
,
2946 got_irelative
, plt_count
);
2948 return new Output_data_plt_x86_64_standard
<64>(layout
, got
, got_plt
,
2953 // Return the section for TLSDESC relocations.
2956 typename Target_x86_64
<size
>::Reloc_section
*
2957 Target_x86_64
<size
>::rela_tlsdesc_section(Layout
* layout
) const
2959 return this->plt_section()->rela_tlsdesc(layout
);
2962 // Create a PLT entry for a global symbol.
2966 Target_x86_64
<size
>::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
2969 if (gsym
->has_plt_offset())
2972 if (this->plt_
== NULL
)
2973 this->make_plt_section(symtab
, layout
);
2975 this->plt_
->add_entry(symtab
, layout
, gsym
);
2978 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
2982 Target_x86_64
<size
>::make_local_ifunc_plt_entry(
2983 Symbol_table
* symtab
, Layout
* layout
,
2984 Sized_relobj_file
<size
, false>* relobj
,
2985 unsigned int local_sym_index
)
2987 if (relobj
->local_has_plt_offset(local_sym_index
))
2989 if (this->plt_
== NULL
)
2990 this->make_plt_section(symtab
, layout
);
2991 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
2994 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
2997 // Return the number of entries in the PLT.
3001 Target_x86_64
<size
>::plt_entry_count() const
3003 if (this->plt_
== NULL
)
3005 return this->plt_
->entry_count();
3008 // Return the offset of the first non-reserved PLT entry.
3012 Target_x86_64
<size
>::first_plt_entry_offset() const
3014 if (this->plt_
== NULL
)
3016 return this->plt_
->first_plt_entry_offset();
3019 // Return the size of each PLT entry.
3023 Target_x86_64
<size
>::plt_entry_size() const
3025 if (this->plt_
== NULL
)
3027 return this->plt_
->get_plt_entry_size();
3030 // Create the GOT and PLT sections for an incremental update.
3033 Output_data_got_base
*
3034 Target_x86_64
<size
>::init_got_plt_for_update(Symbol_table
* symtab
,
3036 unsigned int got_count
,
3037 unsigned int plt_count
)
3039 gold_assert(this->got_
== NULL
);
3041 this->got_
= new Output_data_got
<64, false>(got_count
* 8);
3042 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
3044 | elfcpp::SHF_WRITE
),
3045 this->got_
, ORDER_RELRO_LAST
,
3048 // Add the three reserved entries.
3049 this->got_plt_
= new Output_data_got_plt_x86_64(layout
, (plt_count
+ 3) * 8);
3050 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
3052 | elfcpp::SHF_WRITE
),
3053 this->got_plt_
, ORDER_NON_RELRO_FIRST
,
3056 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3057 this->global_offset_table_
=
3058 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
3059 Symbol_table::PREDEFINED
,
3061 0, 0, elfcpp::STT_OBJECT
,
3063 elfcpp::STV_HIDDEN
, 0,
3066 // If there are any TLSDESC relocations, they get GOT entries in
3067 // .got.plt after the jump slot entries.
3068 // FIXME: Get the count for TLSDESC entries.
3069 this->got_tlsdesc_
= new Output_data_got
<64, false>(0);
3070 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
3071 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
3073 ORDER_NON_RELRO_FIRST
, false);
3075 // If there are any IRELATIVE relocations, they get GOT entries in
3076 // .got.plt after the jump slot and TLSDESC entries.
3077 this->got_irelative_
= new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
3078 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
3079 elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE
,
3080 this->got_irelative_
,
3081 ORDER_NON_RELRO_FIRST
, false);
3083 // Create the PLT section.
3084 this->plt_
= this->make_data_plt(layout
, this->got_
,
3086 this->got_irelative_
,
3089 // Add unwind information if requested.
3090 if (parameters
->options().ld_generated_unwind_info())
3091 this->plt_
->add_eh_frame(layout
);
3093 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
3094 elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
,
3095 this->plt_
, ORDER_PLT
, false);
3097 // Make the sh_info field of .rela.plt point to .plt.
3098 Output_section
* rela_plt_os
= this->plt_
->rela_plt()->output_section();
3099 rela_plt_os
->set_info_section(this->plt_
->output_section());
3101 // Create the rela_dyn section.
3102 this->rela_dyn_section(layout
);
3107 // Reserve a GOT entry for a local symbol, and regenerate any
3108 // necessary dynamic relocations.
3112 Target_x86_64
<size
>::reserve_local_got_entry(
3113 unsigned int got_index
,
3114 Sized_relobj
<size
, false>* obj
,
3116 unsigned int got_type
)
3118 unsigned int got_offset
= got_index
* 8;
3119 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
3121 this->got_
->reserve_local(got_index
, obj
, r_sym
, got_type
);
3124 case GOT_TYPE_STANDARD
:
3125 if (parameters
->options().output_is_position_independent())
3126 rela_dyn
->add_local_relative(obj
, r_sym
, elfcpp::R_X86_64_RELATIVE
,
3127 this->got_
, got_offset
, 0, false);
3129 case GOT_TYPE_TLS_OFFSET
:
3130 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_TPOFF64
,
3131 this->got_
, got_offset
, 0);
3133 case GOT_TYPE_TLS_PAIR
:
3134 this->got_
->reserve_slot(got_index
+ 1);
3135 rela_dyn
->add_local(obj
, r_sym
, elfcpp::R_X86_64_DTPMOD64
,
3136 this->got_
, got_offset
, 0);
3138 case GOT_TYPE_TLS_DESC
:
3139 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
3140 // this->got_->reserve_slot(got_index + 1);
3141 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3142 // this->got_, got_offset, 0);
3149 // Reserve a GOT entry for a global symbol, and regenerate any
3150 // necessary dynamic relocations.
3154 Target_x86_64
<size
>::reserve_global_got_entry(unsigned int got_index
,
3156 unsigned int got_type
)
3158 unsigned int got_offset
= got_index
* 8;
3159 Reloc_section
* rela_dyn
= this->rela_dyn_section(NULL
);
3161 this->got_
->reserve_global(got_index
, gsym
, got_type
);
3164 case GOT_TYPE_STANDARD
:
3165 if (!gsym
->final_value_is_known())
3167 if (gsym
->is_from_dynobj()
3168 || gsym
->is_undefined()
3169 || gsym
->is_preemptible()
3170 || gsym
->type() == elfcpp::STT_GNU_IFUNC
)
3171 rela_dyn
->add_global(gsym
, elfcpp::R_X86_64_GLOB_DAT
,
3172 this->got_
, got_offset
, 0);
3174 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
3175 this->got_
, got_offset
, 0, false);
3178 case GOT_TYPE_TLS_OFFSET
:
3179 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TPOFF64
,
3180 this->got_
, got_offset
, 0, false);
3182 case GOT_TYPE_TLS_PAIR
:
3183 this->got_
->reserve_slot(got_index
+ 1);
3184 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPMOD64
,
3185 this->got_
, got_offset
, 0, false);
3186 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_DTPOFF64
,
3187 this->got_
, got_offset
+ 8, 0, false);
3189 case GOT_TYPE_TLS_DESC
:
3190 this->got_
->reserve_slot(got_index
+ 1);
3191 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_TLSDESC
,
3192 this->got_
, got_offset
, 0, false);
3199 // Register an existing PLT entry for a global symbol.
3203 Target_x86_64
<size
>::register_global_plt_entry(Symbol_table
* symtab
,
3205 unsigned int plt_index
,
3208 gold_assert(this->plt_
!= NULL
);
3209 gold_assert(!gsym
->has_plt_offset());
3211 this->plt_
->reserve_slot(plt_index
);
3213 gsym
->set_plt_offset((plt_index
+ 1) * this->plt_entry_size());
3215 unsigned int got_offset
= (plt_index
+ 3) * 8;
3216 this->plt_
->add_relocation(symtab
, layout
, gsym
, got_offset
);
3219 // Force a COPY relocation for a given symbol.
3223 Target_x86_64
<size
>::emit_copy_reloc(
3224 Symbol_table
* symtab
, Symbol
* sym
, Output_section
* os
, off_t offset
)
3226 this->copy_relocs_
.emit_copy_reloc(symtab
,
3227 symtab
->get_sized_symbol
<size
>(sym
),
3230 this->rela_dyn_section(NULL
));
3233 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
3237 Target_x86_64
<size
>::define_tls_base_symbol(Symbol_table
* symtab
,
3240 if (this->tls_base_symbol_defined_
)
3243 Output_segment
* tls_segment
= layout
->tls_segment();
3244 if (tls_segment
!= NULL
)
3246 bool is_exec
= parameters
->options().output_is_executable();
3247 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
3248 Symbol_table::PREDEFINED
,
3252 elfcpp::STV_HIDDEN
, 0,
3254 ? Symbol::SEGMENT_END
3255 : Symbol::SEGMENT_START
),
3258 this->tls_base_symbol_defined_
= true;
3261 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
3265 Target_x86_64
<size
>::reserve_tlsdesc_entries(Symbol_table
* symtab
,
3268 if (this->plt_
== NULL
)
3269 this->make_plt_section(symtab
, layout
);
3271 if (!this->plt_
->has_tlsdesc_entry())
3273 // Allocate the TLSDESC_GOT entry.
3274 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
3275 unsigned int got_offset
= got
->add_constant(0);
3277 // Allocate the TLSDESC_PLT entry.
3278 this->plt_
->reserve_tlsdesc_entry(got_offset
);
3282 // Create a GOT entry for the TLS module index.
3286 Target_x86_64
<size
>::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
3287 Sized_relobj_file
<size
, false>* object
)
3289 if (this->got_mod_index_offset_
== -1U)
3291 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
3292 Reloc_section
* rela_dyn
= this->rela_dyn_section(layout
);
3293 Output_data_got
<64, false>* got
= this->got_section(symtab
, layout
);
3294 unsigned int got_offset
= got
->add_constant(0);
3295 rela_dyn
->add_local(object
, 0, elfcpp::R_X86_64_DTPMOD64
, got
,
3297 got
->add_constant(0);
3298 this->got_mod_index_offset_
= got_offset
;
3300 return this->got_mod_index_offset_
;
3303 // Optimize the TLS relocation type based on what we know about the
3304 // symbol. IS_FINAL is true if the final address of this symbol is
3305 // known at link time.
3308 tls::Tls_optimization
3309 Target_x86_64
<size
>::optimize_tls_reloc(bool is_final
, int r_type
)
3311 // If we are generating a shared library, then we can't do anything
3313 if (parameters
->options().shared())
3314 return tls::TLSOPT_NONE
;
3318 case elfcpp::R_X86_64_TLSGD
:
3319 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3320 case elfcpp::R_X86_64_TLSDESC_CALL
:
3321 // These are General-Dynamic which permits fully general TLS
3322 // access. Since we know that we are generating an executable,
3323 // we can convert this to Initial-Exec. If we also know that
3324 // this is a local symbol, we can further switch to Local-Exec.
3326 return tls::TLSOPT_TO_LE
;
3327 return tls::TLSOPT_TO_IE
;
3329 case elfcpp::R_X86_64_TLSLD
:
3330 // This is Local-Dynamic, which refers to a local symbol in the
3331 // dynamic TLS block. Since we know that we generating an
3332 // executable, we can switch to Local-Exec.
3333 return tls::TLSOPT_TO_LE
;
3335 case elfcpp::R_X86_64_DTPOFF32
:
3336 case elfcpp::R_X86_64_DTPOFF64
:
3337 // Another Local-Dynamic reloc.
3338 return tls::TLSOPT_TO_LE
;
3340 case elfcpp::R_X86_64_GOTTPOFF
:
3341 // These are Initial-Exec relocs which get the thread offset
3342 // from the GOT. If we know that we are linking against the
3343 // local symbol, we can switch to Local-Exec, which links the
3344 // thread offset into the instruction.
3346 return tls::TLSOPT_TO_LE
;
3347 return tls::TLSOPT_NONE
;
3349 case elfcpp::R_X86_64_TPOFF32
:
3350 // When we already have Local-Exec, there is nothing further we
3352 return tls::TLSOPT_NONE
;
3359 // Get the Reference_flags for a particular relocation.
3363 Target_x86_64
<size
>::Scan::get_reference_flags(unsigned int r_type
)
3367 case elfcpp::R_X86_64_NONE
:
3368 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3369 case elfcpp::R_X86_64_GNU_VTENTRY
:
3370 case elfcpp::R_X86_64_GOTPC32
:
3371 case elfcpp::R_X86_64_GOTPC64
:
3372 // No symbol reference.
3375 case elfcpp::R_X86_64_64
:
3376 case elfcpp::R_X86_64_32
:
3377 case elfcpp::R_X86_64_32S
:
3378 case elfcpp::R_X86_64_16
:
3379 case elfcpp::R_X86_64_8
:
3380 return Symbol::ABSOLUTE_REF
;
3382 case elfcpp::R_X86_64_PC64
:
3383 case elfcpp::R_X86_64_PC32
:
3384 case elfcpp::R_X86_64_PC32_BND
:
3385 case elfcpp::R_X86_64_PC16
:
3386 case elfcpp::R_X86_64_PC8
:
3387 case elfcpp::R_X86_64_GOTOFF64
:
3388 return Symbol::RELATIVE_REF
;
3390 case elfcpp::R_X86_64_PLT32
:
3391 case elfcpp::R_X86_64_PLT32_BND
:
3392 case elfcpp::R_X86_64_PLTOFF64
:
3393 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
3395 case elfcpp::R_X86_64_GOT64
:
3396 case elfcpp::R_X86_64_GOT32
:
3397 case elfcpp::R_X86_64_GOTPCREL64
:
3398 case elfcpp::R_X86_64_GOTPCREL
:
3399 case elfcpp::R_X86_64_GOTPCRELX
:
3400 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3401 case elfcpp::R_X86_64_GOTPLT64
:
3403 return Symbol::ABSOLUTE_REF
;
3405 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3406 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3407 case elfcpp::R_X86_64_TLSDESC_CALL
:
3408 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3409 case elfcpp::R_X86_64_DTPOFF32
:
3410 case elfcpp::R_X86_64_DTPOFF64
:
3411 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3412 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3413 return Symbol::TLS_REF
;
3415 case elfcpp::R_X86_64_COPY
:
3416 case elfcpp::R_X86_64_GLOB_DAT
:
3417 case elfcpp::R_X86_64_JUMP_SLOT
:
3418 case elfcpp::R_X86_64_RELATIVE
:
3419 case elfcpp::R_X86_64_IRELATIVE
:
3420 case elfcpp::R_X86_64_TPOFF64
:
3421 case elfcpp::R_X86_64_DTPMOD64
:
3422 case elfcpp::R_X86_64_TLSDESC
:
3423 case elfcpp::R_X86_64_SIZE32
:
3424 case elfcpp::R_X86_64_SIZE64
:
3426 // Not expected. We will give an error later.
3431 // Report an unsupported relocation against a local symbol.
3435 Target_x86_64
<size
>::Scan::unsupported_reloc_local(
3436 Sized_relobj_file
<size
, false>* object
,
3437 unsigned int r_type
)
3439 gold_error(_("%s: unsupported reloc %u against local symbol"),
3440 object
->name().c_str(), r_type
);
3443 // We are about to emit a dynamic relocation of type R_TYPE. If the
3444 // dynamic linker does not support it, issue an error. The GNU linker
3445 // only issues a non-PIC error for an allocated read-only section.
3446 // Here we know the section is allocated, but we don't know that it is
3447 // read-only. But we check for all the relocation types which the
3448 // glibc dynamic linker supports, so it seems appropriate to issue an
3449 // error even if the section is not read-only. If GSYM is not NULL,
3450 // it is the symbol the relocation is against; if it is NULL, the
3451 // relocation is against a local symbol.
3455 Target_x86_64
<size
>::Scan::check_non_pic(Relobj
* object
, unsigned int r_type
,
3460 // These are the relocation types supported by glibc for x86_64
3461 // which should always work.
3462 case elfcpp::R_X86_64_RELATIVE
:
3463 case elfcpp::R_X86_64_IRELATIVE
:
3464 case elfcpp::R_X86_64_GLOB_DAT
:
3465 case elfcpp::R_X86_64_JUMP_SLOT
:
3466 case elfcpp::R_X86_64_DTPMOD64
:
3467 case elfcpp::R_X86_64_DTPOFF64
:
3468 case elfcpp::R_X86_64_TPOFF64
:
3469 case elfcpp::R_X86_64_64
:
3470 case elfcpp::R_X86_64_COPY
:
3473 // glibc supports these reloc types, but they can overflow.
3474 case elfcpp::R_X86_64_PC32
:
3475 case elfcpp::R_X86_64_PC32_BND
:
3476 // A PC relative reference is OK against a local symbol or if
3477 // the symbol is defined locally.
3479 || (!gsym
->is_from_dynobj()
3480 && !gsym
->is_undefined()
3481 && !gsym
->is_preemptible()))
3484 case elfcpp::R_X86_64_32
:
3485 // R_X86_64_32 is OK for x32.
3486 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
3488 if (this->issued_non_pic_error_
)
3490 gold_assert(parameters
->options().output_is_position_independent());
3492 object
->error(_("requires dynamic R_X86_64_32 reloc which may "
3493 "overflow at runtime; recompile with -fPIC"));
3499 case elfcpp::R_X86_64_32
:
3500 r_name
= "R_X86_64_32";
3502 case elfcpp::R_X86_64_PC32
:
3503 r_name
= "R_X86_64_PC32";
3505 case elfcpp::R_X86_64_PC32_BND
:
3506 r_name
= "R_X86_64_PC32_BND";
3512 object
->error(_("requires dynamic %s reloc against '%s' "
3513 "which may overflow at runtime; recompile "
3515 r_name
, gsym
->name());
3517 this->issued_non_pic_error_
= true;
3521 // This prevents us from issuing more than one error per reloc
3522 // section. But we can still wind up issuing more than one
3523 // error per object file.
3524 if (this->issued_non_pic_error_
)
3526 gold_assert(parameters
->options().output_is_position_independent());
3527 object
->error(_("requires unsupported dynamic reloc %u; "
3528 "recompile with -fPIC"),
3530 this->issued_non_pic_error_
= true;
3533 case elfcpp::R_X86_64_NONE
:
3538 // Return whether we need to make a PLT entry for a relocation of the
3539 // given type against a STT_GNU_IFUNC symbol.
3543 Target_x86_64
<size
>::Scan::reloc_needs_plt_for_ifunc(
3544 Sized_relobj_file
<size
, false>* object
,
3545 unsigned int r_type
)
3547 int flags
= Scan::get_reference_flags(r_type
);
3548 if (flags
& Symbol::TLS_REF
)
3549 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
3550 object
->name().c_str(), r_type
);
3554 // Scan a relocation for a local symbol.
3558 Target_x86_64
<size
>::Scan::local(Symbol_table
* symtab
,
3560 Target_x86_64
<size
>* target
,
3561 Sized_relobj_file
<size
, false>* object
,
3562 unsigned int data_shndx
,
3563 Output_section
* output_section
,
3564 const elfcpp::Rela
<size
, false>& reloc
,
3565 unsigned int r_type
,
3566 const elfcpp::Sym
<size
, false>& lsym
,
3572 // A local STT_GNU_IFUNC symbol may require a PLT entry.
3573 bool is_ifunc
= lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
;
3574 if (is_ifunc
&& this->reloc_needs_plt_for_ifunc(object
, r_type
))
3576 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3577 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
3582 case elfcpp::R_X86_64_NONE
:
3583 case elfcpp::R_X86_64_GNU_VTINHERIT
:
3584 case elfcpp::R_X86_64_GNU_VTENTRY
:
3587 case elfcpp::R_X86_64_64
:
3588 // If building a shared library (or a position-independent
3589 // executable), we need to create a dynamic relocation for this
3590 // location. The relocation applied at link time will apply the
3591 // link-time value, so we flag the location with an
3592 // R_X86_64_RELATIVE relocation so the dynamic loader can
3593 // relocate it easily.
3594 if (parameters
->options().output_is_position_independent())
3596 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3597 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3598 rela_dyn
->add_local_relative(object
, r_sym
,
3600 ? elfcpp::R_X86_64_RELATIVE64
3601 : elfcpp::R_X86_64_RELATIVE
),
3602 output_section
, data_shndx
,
3603 reloc
.get_r_offset(),
3604 reloc
.get_r_addend(), is_ifunc
);
3608 case elfcpp::R_X86_64_32
:
3609 case elfcpp::R_X86_64_32S
:
3610 case elfcpp::R_X86_64_16
:
3611 case elfcpp::R_X86_64_8
:
3612 // If building a shared library (or a position-independent
3613 // executable), we need to create a dynamic relocation for this
3614 // location. We can't use an R_X86_64_RELATIVE relocation
3615 // because that is always a 64-bit relocation.
3616 if (parameters
->options().output_is_position_independent())
3618 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
3619 if (size
== 32 && r_type
== elfcpp::R_X86_64_32
)
3621 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3622 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3623 rela_dyn
->add_local_relative(object
, r_sym
,
3624 elfcpp::R_X86_64_RELATIVE
,
3625 output_section
, data_shndx
,
3626 reloc
.get_r_offset(),
3627 reloc
.get_r_addend(), is_ifunc
);
3631 this->check_non_pic(object
, r_type
, NULL
);
3633 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3634 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3635 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
3636 rela_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
3637 data_shndx
, reloc
.get_r_offset(),
3638 reloc
.get_r_addend());
3641 gold_assert(lsym
.get_st_value() == 0);
3642 unsigned int shndx
= lsym
.get_st_shndx();
3644 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
3647 object
->error(_("section symbol %u has bad shndx %u"),
3650 rela_dyn
->add_local_section(object
, shndx
,
3651 r_type
, output_section
,
3652 data_shndx
, reloc
.get_r_offset(),
3653 reloc
.get_r_addend());
3658 case elfcpp::R_X86_64_PC64
:
3659 case elfcpp::R_X86_64_PC32
:
3660 case elfcpp::R_X86_64_PC32_BND
:
3661 case elfcpp::R_X86_64_PC16
:
3662 case elfcpp::R_X86_64_PC8
:
3665 case elfcpp::R_X86_64_PLT32
:
3666 case elfcpp::R_X86_64_PLT32_BND
:
3667 // Since we know this is a local symbol, we can handle this as a
3671 case elfcpp::R_X86_64_GOTPC32
:
3672 case elfcpp::R_X86_64_GOTOFF64
:
3673 case elfcpp::R_X86_64_GOTPC64
:
3674 case elfcpp::R_X86_64_PLTOFF64
:
3675 // We need a GOT section.
3676 target
->got_section(symtab
, layout
);
3677 // For PLTOFF64, we'd normally want a PLT section, but since we
3678 // know this is a local symbol, no PLT is needed.
3681 case elfcpp::R_X86_64_GOT64
:
3682 case elfcpp::R_X86_64_GOT32
:
3683 case elfcpp::R_X86_64_GOTPCREL64
:
3684 case elfcpp::R_X86_64_GOTPCREL
:
3685 case elfcpp::R_X86_64_GOTPCRELX
:
3686 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3687 case elfcpp::R_X86_64_GOTPLT64
:
3689 // The symbol requires a GOT section.
3690 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
3692 // If the relocation symbol isn't IFUNC,
3693 // and is local, then we will convert
3694 // mov foo@GOTPCREL(%rip), %reg
3695 // to lea foo(%rip), %reg.
3696 // in Relocate::relocate.
3697 if (!parameters
->incremental()
3698 && (r_type
== elfcpp::R_X86_64_GOTPCREL
3699 || r_type
== elfcpp::R_X86_64_GOTPCRELX
3700 || r_type
== elfcpp::R_X86_64_REX_GOTPCRELX
)
3701 && reloc
.get_r_offset() >= 2
3704 section_size_type stype
;
3705 const unsigned char* view
= object
->section_contents(data_shndx
,
3707 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
3711 // The symbol requires a GOT entry.
3712 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3714 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
3715 // lets function pointers compare correctly with shared
3716 // libraries. Otherwise we would need an IRELATIVE reloc.
3719 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
3721 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
3724 // If we are generating a shared object, we need to add a
3725 // dynamic relocation for this symbol's GOT entry.
3726 if (parameters
->options().output_is_position_independent())
3728 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
3729 // R_X86_64_RELATIVE assumes a 64-bit relocation.
3730 if (r_type
!= elfcpp::R_X86_64_GOT32
)
3732 unsigned int got_offset
=
3733 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
3734 rela_dyn
->add_local_relative(object
, r_sym
,
3735 elfcpp::R_X86_64_RELATIVE
,
3736 got
, got_offset
, 0, is_ifunc
);
3740 this->check_non_pic(object
, r_type
, NULL
);
3742 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
3743 rela_dyn
->add_local(
3744 object
, r_sym
, r_type
, got
,
3745 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
), 0);
3749 // For GOTPLT64, we'd normally want a PLT section, but since
3750 // we know this is a local symbol, no PLT is needed.
3754 case elfcpp::R_X86_64_COPY
:
3755 case elfcpp::R_X86_64_GLOB_DAT
:
3756 case elfcpp::R_X86_64_JUMP_SLOT
:
3757 case elfcpp::R_X86_64_RELATIVE
:
3758 case elfcpp::R_X86_64_IRELATIVE
:
3759 // These are outstanding tls relocs, which are unexpected when linking
3760 case elfcpp::R_X86_64_TPOFF64
:
3761 case elfcpp::R_X86_64_DTPMOD64
:
3762 case elfcpp::R_X86_64_TLSDESC
:
3763 gold_error(_("%s: unexpected reloc %u in object file"),
3764 object
->name().c_str(), r_type
);
3767 // These are initial tls relocs, which are expected when linking
3768 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
3769 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
3770 case elfcpp::R_X86_64_TLSDESC_CALL
:
3771 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3772 case elfcpp::R_X86_64_DTPOFF32
:
3773 case elfcpp::R_X86_64_DTPOFF64
:
3774 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3775 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3777 bool output_is_shared
= parameters
->options().shared();
3778 const tls::Tls_optimization optimized_type
3779 = Target_x86_64
<size
>::optimize_tls_reloc(!output_is_shared
,
3783 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
3784 if (optimized_type
== tls::TLSOPT_NONE
)
3786 // Create a pair of GOT entries for the module index and
3787 // dtv-relative offset.
3788 Output_data_got
<64, false>* got
3789 = target
->got_section(symtab
, layout
);
3790 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3791 unsigned int shndx
= lsym
.get_st_shndx();
3793 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
3795 object
->error(_("local symbol %u has bad shndx %u"),
3798 got
->add_local_pair_with_rel(object
, r_sym
,
3801 target
->rela_dyn_section(layout
),
3802 elfcpp::R_X86_64_DTPMOD64
);
3804 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3805 unsupported_reloc_local(object
, r_type
);
3808 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
3809 target
->define_tls_base_symbol(symtab
, layout
);
3810 if (optimized_type
== tls::TLSOPT_NONE
)
3812 // Create reserved PLT and GOT entries for the resolver.
3813 target
->reserve_tlsdesc_entries(symtab
, layout
);
3815 // Generate a double GOT entry with an
3816 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
3817 // is resolved lazily, so the GOT entry needs to be in
3818 // an area in .got.plt, not .got. Call got_section to
3819 // make sure the section has been created.
3820 target
->got_section(symtab
, layout
);
3821 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
3822 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3823 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
3825 unsigned int got_offset
= got
->add_constant(0);
3826 got
->add_constant(0);
3827 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
3829 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
3830 // We store the arguments we need in a vector, and
3831 // use the index into the vector as the parameter
3832 // to pass to the target specific routines.
3833 uintptr_t intarg
= target
->add_tlsdesc_info(object
, r_sym
);
3834 void* arg
= reinterpret_cast<void*>(intarg
);
3835 rt
->add_target_specific(elfcpp::R_X86_64_TLSDESC
, arg
,
3836 got
, got_offset
, 0);
3839 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3840 unsupported_reloc_local(object
, r_type
);
3843 case elfcpp::R_X86_64_TLSDESC_CALL
:
3846 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
3847 if (optimized_type
== tls::TLSOPT_NONE
)
3849 // Create a GOT entry for the module index.
3850 target
->got_mod_index_entry(symtab
, layout
, object
);
3852 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3853 unsupported_reloc_local(object
, r_type
);
3856 case elfcpp::R_X86_64_DTPOFF32
:
3857 case elfcpp::R_X86_64_DTPOFF64
:
3860 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
3861 layout
->set_has_static_tls();
3862 if (optimized_type
== tls::TLSOPT_NONE
)
3864 // Create a GOT entry for the tp-relative offset.
3865 Output_data_got
<64, false>* got
3866 = target
->got_section(symtab
, layout
);
3867 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(reloc
.get_r_info());
3868 got
->add_local_with_rel(object
, r_sym
, GOT_TYPE_TLS_OFFSET
,
3869 target
->rela_dyn_section(layout
),
3870 elfcpp::R_X86_64_TPOFF64
);
3872 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
3873 unsupported_reloc_local(object
, r_type
);
3876 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
3877 layout
->set_has_static_tls();
3878 if (output_is_shared
)
3879 unsupported_reloc_local(object
, r_type
);
3888 case elfcpp::R_X86_64_SIZE32
:
3889 case elfcpp::R_X86_64_SIZE64
:
3891 gold_error(_("%s: unsupported reloc %u against local symbol"),
3892 object
->name().c_str(), r_type
);
3898 // Report an unsupported relocation against a global symbol.
3902 Target_x86_64
<size
>::Scan::unsupported_reloc_global(
3903 Sized_relobj_file
<size
, false>* object
,
3904 unsigned int r_type
,
3907 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3908 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
3911 // Returns true if this relocation type could be that of a function pointer.
3914 Target_x86_64
<size
>::Scan::possible_function_pointer_reloc(
3915 Sized_relobj_file
<size
, false>* src_obj
,
3916 unsigned int src_indx
,
3917 unsigned int r_offset
,
3918 unsigned int r_type
)
3922 case elfcpp::R_X86_64_64
:
3923 case elfcpp::R_X86_64_32
:
3924 case elfcpp::R_X86_64_32S
:
3925 case elfcpp::R_X86_64_16
:
3926 case elfcpp::R_X86_64_8
:
3927 case elfcpp::R_X86_64_GOT64
:
3928 case elfcpp::R_X86_64_GOT32
:
3929 case elfcpp::R_X86_64_GOTPCREL64
:
3930 case elfcpp::R_X86_64_GOTPCREL
:
3931 case elfcpp::R_X86_64_GOTPCRELX
:
3932 case elfcpp::R_X86_64_REX_GOTPCRELX
:
3933 case elfcpp::R_X86_64_GOTPLT64
:
3937 case elfcpp::R_X86_64_PC32
:
3939 // This relocation may be used both for function calls and
3940 // for taking address of a function. We distinguish between
3941 // them by checking the opcodes.
3942 uint64_t sh_flags
= src_obj
->section_flags(src_indx
);
3943 bool is_executable
= (sh_flags
& elfcpp::SHF_EXECINSTR
) != 0;
3946 section_size_type stype
;
3947 const unsigned char* view
= src_obj
->section_contents(src_indx
,
3953 && view
[r_offset
- 1] == 0xe8)
3958 && view
[r_offset
- 1] == 0xe9)
3961 // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3963 && view
[r_offset
- 2] == 0x0f
3964 && view
[r_offset
- 1] >= 0x80
3965 && view
[r_offset
- 1] <= 0x8f)
3969 // Be conservative and treat all others as function pointers.
3976 // For safe ICF, scan a relocation for a local symbol to check if it
3977 // corresponds to a function pointer being taken. In that case mark
3978 // the function whose pointer was taken as not foldable.
3982 Target_x86_64
<size
>::Scan::local_reloc_may_be_function_pointer(
3985 Target_x86_64
<size
>* ,
3986 Sized_relobj_file
<size
, false>* src_obj
,
3987 unsigned int src_indx
,
3989 const elfcpp::Rela
<size
, false>& reloc
,
3990 unsigned int r_type
,
3991 const elfcpp::Sym
<size
, false>&)
3993 // When building a shared library, do not fold any local symbols as it is
3994 // not possible to distinguish pointer taken versus a call by looking at
3995 // the relocation types.
3996 if (parameters
->options().shared())
3999 return possible_function_pointer_reloc(src_obj
, src_indx
,
4000 reloc
.get_r_offset(), r_type
);
4003 // For safe ICF, scan a relocation for a global symbol to check if it
4004 // corresponds to a function pointer being taken. In that case mark
4005 // the function whose pointer was taken as not foldable.
4009 Target_x86_64
<size
>::Scan::global_reloc_may_be_function_pointer(
4012 Target_x86_64
<size
>* ,
4013 Sized_relobj_file
<size
, false>* src_obj
,
4014 unsigned int src_indx
,
4016 const elfcpp::Rela
<size
, false>& reloc
,
4017 unsigned int r_type
,
4020 // When building a shared library, do not fold symbols whose visibility
4021 // is hidden, internal or protected.
4022 if (parameters
->options().shared()
4023 && (gsym
->visibility() == elfcpp::STV_INTERNAL
4024 || gsym
->visibility() == elfcpp::STV_PROTECTED
4025 || gsym
->visibility() == elfcpp::STV_HIDDEN
))
4028 return possible_function_pointer_reloc(src_obj
, src_indx
,
4029 reloc
.get_r_offset(), r_type
);
4032 // Scan a relocation for a global symbol.
4036 Target_x86_64
<size
>::Scan::global(Symbol_table
* symtab
,
4038 Target_x86_64
<size
>* target
,
4039 Sized_relobj_file
<size
, false>* object
,
4040 unsigned int data_shndx
,
4041 Output_section
* output_section
,
4042 const elfcpp::Rela
<size
, false>& reloc
,
4043 unsigned int r_type
,
4046 // A STT_GNU_IFUNC symbol may require a PLT entry.
4047 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
4048 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
4049 target
->make_plt_entry(symtab
, layout
, gsym
);
4053 case elfcpp::R_X86_64_NONE
:
4054 case elfcpp::R_X86_64_GNU_VTINHERIT
:
4055 case elfcpp::R_X86_64_GNU_VTENTRY
:
4058 case elfcpp::R_X86_64_64
:
4059 case elfcpp::R_X86_64_32
:
4060 case elfcpp::R_X86_64_32S
:
4061 case elfcpp::R_X86_64_16
:
4062 case elfcpp::R_X86_64_8
:
4064 // Make a PLT entry if necessary.
4065 if (gsym
->needs_plt_entry())
4067 target
->make_plt_entry(symtab
, layout
, gsym
);
4068 // Since this is not a PC-relative relocation, we may be
4069 // taking the address of a function. In that case we need to
4070 // set the entry in the dynamic symbol table to the address of
4072 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
4073 gsym
->set_needs_dynsym_value();
4075 // Make a dynamic relocation if necessary.
4076 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
4078 if (!parameters
->options().output_is_position_independent()
4079 && gsym
->may_need_copy_reloc())
4081 target
->copy_reloc(symtab
, layout
, object
,
4082 data_shndx
, output_section
, gsym
, reloc
);
4084 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
4085 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
4086 && gsym
->type() == elfcpp::STT_GNU_IFUNC
4087 && gsym
->can_use_relative_reloc(false)
4088 && !gsym
->is_from_dynobj()
4089 && !gsym
->is_undefined()
4090 && !gsym
->is_preemptible())
4092 // Use an IRELATIVE reloc for a locally defined
4093 // STT_GNU_IFUNC symbol. This makes a function
4094 // address in a PIE executable match the address in a
4095 // shared library that it links against.
4096 Reloc_section
* rela_dyn
=
4097 target
->rela_irelative_section(layout
);
4098 unsigned int r_type
= elfcpp::R_X86_64_IRELATIVE
;
4099 rela_dyn
->add_symbolless_global_addend(gsym
, r_type
,
4100 output_section
, object
,
4102 reloc
.get_r_offset(),
4103 reloc
.get_r_addend());
4105 else if (((size
== 64 && r_type
== elfcpp::R_X86_64_64
)
4106 || (size
== 32 && r_type
== elfcpp::R_X86_64_32
))
4107 && gsym
->can_use_relative_reloc(false))
4109 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4110 rela_dyn
->add_global_relative(gsym
, elfcpp::R_X86_64_RELATIVE
,
4111 output_section
, object
,
4113 reloc
.get_r_offset(),
4114 reloc
.get_r_addend(), false);
4118 this->check_non_pic(object
, r_type
, gsym
);
4119 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4120 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
4121 data_shndx
, reloc
.get_r_offset(),
4122 reloc
.get_r_addend());
4128 case elfcpp::R_X86_64_PC64
:
4129 case elfcpp::R_X86_64_PC32
:
4130 case elfcpp::R_X86_64_PC32_BND
:
4131 case elfcpp::R_X86_64_PC16
:
4132 case elfcpp::R_X86_64_PC8
:
4134 // Make a PLT entry if necessary.
4135 if (gsym
->needs_plt_entry())
4136 target
->make_plt_entry(symtab
, layout
, gsym
);
4137 // Make a dynamic relocation if necessary.
4138 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
4140 if (parameters
->options().output_is_executable()
4141 && gsym
->may_need_copy_reloc())
4143 target
->copy_reloc(symtab
, layout
, object
,
4144 data_shndx
, output_section
, gsym
, reloc
);
4148 this->check_non_pic(object
, r_type
, gsym
);
4149 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4150 rela_dyn
->add_global(gsym
, r_type
, output_section
, object
,
4151 data_shndx
, reloc
.get_r_offset(),
4152 reloc
.get_r_addend());
4158 case elfcpp::R_X86_64_GOT64
:
4159 case elfcpp::R_X86_64_GOT32
:
4160 case elfcpp::R_X86_64_GOTPCREL64
:
4161 case elfcpp::R_X86_64_GOTPCREL
:
4162 case elfcpp::R_X86_64_GOTPCRELX
:
4163 case elfcpp::R_X86_64_REX_GOTPCRELX
:
4164 case elfcpp::R_X86_64_GOTPLT64
:
4166 // The symbol requires a GOT entry.
4167 Output_data_got
<64, false>* got
= target
->got_section(symtab
, layout
);
4169 // If we convert this from
4170 // mov foo@GOTPCREL(%rip), %reg
4171 // to lea foo(%rip), %reg.
4174 // (callq|jmpq) *foo@GOTPCRELX(%rip) to
4176 // in Relocate::relocate, then there is nothing to do here.
4177 // We cannot make these optimizations in incremental linking mode,
4178 // because we look at the opcode to decide whether or not to make
4179 // change, and during an incremental update, the change may have
4180 // already been applied.
4182 Lazy_view
<size
> view(object
, data_shndx
);
4183 size_t r_offset
= reloc
.get_r_offset();
4184 if (!parameters
->incremental()
4186 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
, r_type
,
4190 if (!parameters
->incremental()
4192 && Target_x86_64
<size
>::can_convert_callq_to_direct(gsym
, r_type
,
4197 if (gsym
->final_value_is_known())
4199 // For a STT_GNU_IFUNC symbol we want the PLT address.
4200 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
4201 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
4203 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
4207 // If this symbol is not fully resolved, we need to add a
4208 // dynamic relocation for it.
4209 Reloc_section
* rela_dyn
= target
->rela_dyn_section(layout
);
4211 // Use a GLOB_DAT rather than a RELATIVE reloc if:
4213 // 1) The symbol may be defined in some other module.
4215 // 2) We are building a shared library and this is a
4216 // protected symbol; using GLOB_DAT means that the dynamic
4217 // linker can use the address of the PLT in the main
4218 // executable when appropriate so that function address
4219 // comparisons work.
4221 // 3) This is a STT_GNU_IFUNC symbol in position dependent
4222 // code, again so that function address comparisons work.
4223 if (gsym
->is_from_dynobj()
4224 || gsym
->is_undefined()
4225 || gsym
->is_preemptible()
4226 || (gsym
->visibility() == elfcpp::STV_PROTECTED
4227 && parameters
->options().shared())
4228 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
4229 && parameters
->options().output_is_position_independent()))
4230 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
, rela_dyn
,
4231 elfcpp::R_X86_64_GLOB_DAT
);
4234 // For a STT_GNU_IFUNC symbol we want to write the PLT
4235 // offset into the GOT, so that function pointer
4236 // comparisons work correctly.
4238 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
4239 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
4242 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
4243 // Tell the dynamic linker to use the PLT address
4244 // when resolving relocations.
4245 if (gsym
->is_from_dynobj()
4246 && !parameters
->options().shared())
4247 gsym
->set_needs_dynsym_value();
4251 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
4252 rela_dyn
->add_global_relative(gsym
,
4253 elfcpp::R_X86_64_RELATIVE
,
4254 got
, got_off
, 0, false);
4261 case elfcpp::R_X86_64_PLT32
:
4262 case elfcpp::R_X86_64_PLT32_BND
:
4263 // If the symbol is fully resolved, this is just a PC32 reloc.
4264 // Otherwise we need a PLT entry.
4265 if (gsym
->final_value_is_known())
4267 // If building a shared library, we can also skip the PLT entry
4268 // if the symbol is defined in the output file and is protected
4270 if (gsym
->is_defined()
4271 && !gsym
->is_from_dynobj()
4272 && !gsym
->is_preemptible())
4274 target
->make_plt_entry(symtab
, layout
, gsym
);
4277 case elfcpp::R_X86_64_GOTPC32
:
4278 case elfcpp::R_X86_64_GOTOFF64
:
4279 case elfcpp::R_X86_64_GOTPC64
:
4280 case elfcpp::R_X86_64_PLTOFF64
:
4281 // We need a GOT section.
4282 target
->got_section(symtab
, layout
);
4283 // For PLTOFF64, we also need a PLT entry (but only if the
4284 // symbol is not fully resolved).
4285 if (r_type
== elfcpp::R_X86_64_PLTOFF64
4286 && !gsym
->final_value_is_known())
4287 target
->make_plt_entry(symtab
, layout
, gsym
);
4290 case elfcpp::R_X86_64_COPY
:
4291 case elfcpp::R_X86_64_GLOB_DAT
:
4292 case elfcpp::R_X86_64_JUMP_SLOT
:
4293 case elfcpp::R_X86_64_RELATIVE
:
4294 case elfcpp::R_X86_64_IRELATIVE
:
4295 // These are outstanding tls relocs, which are unexpected when linking
4296 case elfcpp::R_X86_64_TPOFF64
:
4297 case elfcpp::R_X86_64_DTPMOD64
:
4298 case elfcpp::R_X86_64_TLSDESC
:
4299 gold_error(_("%s: unexpected reloc %u in object file"),
4300 object
->name().c_str(), r_type
);
4303 // These are initial tls relocs, which are expected for global()
4304 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
4305 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
4306 case elfcpp::R_X86_64_TLSDESC_CALL
:
4307 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4308 case elfcpp::R_X86_64_DTPOFF32
:
4309 case elfcpp::R_X86_64_DTPOFF64
:
4310 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4311 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4313 // For the Initial-Exec model, we can treat undef symbols as final
4314 // when building an executable.
4315 const bool is_final
= (gsym
->final_value_is_known() ||
4316 (r_type
== elfcpp::R_X86_64_GOTTPOFF
&&
4317 gsym
->is_undefined() &&
4318 parameters
->options().output_is_executable()));
4319 const tls::Tls_optimization optimized_type
4320 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
4323 case elfcpp::R_X86_64_TLSGD
: // General-dynamic
4324 if (optimized_type
== tls::TLSOPT_NONE
)
4326 // Create a pair of GOT entries for the module index and
4327 // dtv-relative offset.
4328 Output_data_got
<64, false>* got
4329 = target
->got_section(symtab
, layout
);
4330 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
4331 target
->rela_dyn_section(layout
),
4332 elfcpp::R_X86_64_DTPMOD64
,
4333 elfcpp::R_X86_64_DTPOFF64
);
4335 else if (optimized_type
== tls::TLSOPT_TO_IE
)
4337 // Create a GOT entry for the tp-relative offset.
4338 Output_data_got
<64, false>* got
4339 = target
->got_section(symtab
, layout
);
4340 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
4341 target
->rela_dyn_section(layout
),
4342 elfcpp::R_X86_64_TPOFF64
);
4344 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4345 unsupported_reloc_global(object
, r_type
, gsym
);
4348 case elfcpp::R_X86_64_GOTPC32_TLSDESC
:
4349 target
->define_tls_base_symbol(symtab
, layout
);
4350 if (optimized_type
== tls::TLSOPT_NONE
)
4352 // Create reserved PLT and GOT entries for the resolver.
4353 target
->reserve_tlsdesc_entries(symtab
, layout
);
4355 // Create a double GOT entry with an R_X86_64_TLSDESC
4356 // reloc. The R_X86_64_TLSDESC reloc is resolved
4357 // lazily, so the GOT entry needs to be in an area in
4358 // .got.plt, not .got. Call got_section to make sure
4359 // the section has been created.
4360 target
->got_section(symtab
, layout
);
4361 Output_data_got
<64, false>* got
= target
->got_tlsdesc_section();
4362 Reloc_section
* rt
= target
->rela_tlsdesc_section(layout
);
4363 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
4364 elfcpp::R_X86_64_TLSDESC
, 0);
4366 else if (optimized_type
== tls::TLSOPT_TO_IE
)
4368 // Create a GOT entry for the tp-relative offset.
4369 Output_data_got
<64, false>* got
4370 = target
->got_section(symtab
, layout
);
4371 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
4372 target
->rela_dyn_section(layout
),
4373 elfcpp::R_X86_64_TPOFF64
);
4375 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4376 unsupported_reloc_global(object
, r_type
, gsym
);
4379 case elfcpp::R_X86_64_TLSDESC_CALL
:
4382 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4383 if (optimized_type
== tls::TLSOPT_NONE
)
4385 // Create a GOT entry for the module index.
4386 target
->got_mod_index_entry(symtab
, layout
, object
);
4388 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4389 unsupported_reloc_global(object
, r_type
, gsym
);
4392 case elfcpp::R_X86_64_DTPOFF32
:
4393 case elfcpp::R_X86_64_DTPOFF64
:
4396 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4397 layout
->set_has_static_tls();
4398 if (optimized_type
== tls::TLSOPT_NONE
)
4400 // Create a GOT entry for the tp-relative offset.
4401 Output_data_got
<64, false>* got
4402 = target
->got_section(symtab
, layout
);
4403 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_OFFSET
,
4404 target
->rela_dyn_section(layout
),
4405 elfcpp::R_X86_64_TPOFF64
);
4407 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
4408 unsupported_reloc_global(object
, r_type
, gsym
);
4411 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4412 layout
->set_has_static_tls();
4413 if (parameters
->options().shared())
4414 unsupported_reloc_global(object
, r_type
, gsym
);
4423 case elfcpp::R_X86_64_SIZE32
:
4424 case elfcpp::R_X86_64_SIZE64
:
4426 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
4427 object
->name().c_str(), r_type
,
4428 gsym
->demangled_name().c_str());
4435 Target_x86_64
<size
>::gc_process_relocs(Symbol_table
* symtab
,
4437 Sized_relobj_file
<size
, false>* object
,
4438 unsigned int data_shndx
,
4439 unsigned int sh_type
,
4440 const unsigned char* prelocs
,
4442 Output_section
* output_section
,
4443 bool needs_special_offset_handling
,
4444 size_t local_symbol_count
,
4445 const unsigned char* plocal_symbols
)
4447 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4450 if (sh_type
== elfcpp::SHT_REL
)
4455 gold::gc_process_relocs
<size
, false, Target_x86_64
<size
>, Scan
,
4465 needs_special_offset_handling
,
4470 // Scan relocations for a section.
4474 Target_x86_64
<size
>::scan_relocs(Symbol_table
* symtab
,
4476 Sized_relobj_file
<size
, false>* object
,
4477 unsigned int data_shndx
,
4478 unsigned int sh_type
,
4479 const unsigned char* prelocs
,
4481 Output_section
* output_section
,
4482 bool needs_special_offset_handling
,
4483 size_t local_symbol_count
,
4484 const unsigned char* plocal_symbols
)
4486 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
4489 if (sh_type
== elfcpp::SHT_REL
)
4491 gold_error(_("%s: unsupported REL reloc section"),
4492 object
->name().c_str());
4496 gold::scan_relocs
<size
, false, Target_x86_64
<size
>, Scan
, Classify_reloc
>(
4505 needs_special_offset_handling
,
4510 // Finalize the sections.
4514 Target_x86_64
<size
>::do_finalize_sections(
4516 const Input_objects
*,
4517 Symbol_table
* symtab
)
4519 const Reloc_section
* rel_plt
= (this->plt_
== NULL
4521 : this->plt_
->rela_plt());
4522 layout
->add_target_dynamic_tags(false, this->got_plt_
, rel_plt
,
4523 this->rela_dyn_
, true, false);
4525 // Fill in some more dynamic tags.
4526 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
4529 if (this->plt_
!= NULL
4530 && this->plt_
->output_section() != NULL
4531 && this->plt_
->has_tlsdesc_entry())
4533 unsigned int plt_offset
= this->plt_
->get_tlsdesc_plt_offset();
4534 unsigned int got_offset
= this->plt_
->get_tlsdesc_got_offset();
4535 this->got_
->finalize_data_size();
4536 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT
,
4537 this->plt_
, plt_offset
);
4538 odyn
->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT
,
4539 this->got_
, got_offset
);
4543 // Emit any relocs we saved in an attempt to avoid generating COPY
4545 if (this->copy_relocs_
.any_saved_relocs())
4546 this->copy_relocs_
.emit(this->rela_dyn_section(layout
));
4548 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
4549 // the .got.plt section.
4550 Symbol
* sym
= this->global_offset_table_
;
4553 uint64_t data_size
= this->got_plt_
->current_data_size();
4554 symtab
->get_sized_symbol
<size
>(sym
)->set_symsize(data_size
);
4557 if (parameters
->doing_static_link()
4558 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
4560 // If linking statically, make sure that the __rela_iplt symbols
4561 // were defined if necessary, even if we didn't create a PLT.
4562 static const Define_symbol_in_segment syms
[] =
4565 "__rela_iplt_start", // name
4566 elfcpp::PT_LOAD
, // segment_type
4567 elfcpp::PF_W
, // segment_flags_set
4568 elfcpp::PF(0), // segment_flags_clear
4571 elfcpp::STT_NOTYPE
, // type
4572 elfcpp::STB_GLOBAL
, // binding
4573 elfcpp::STV_HIDDEN
, // visibility
4575 Symbol::SEGMENT_START
, // offset_from_base
4579 "__rela_iplt_end", // name
4580 elfcpp::PT_LOAD
, // segment_type
4581 elfcpp::PF_W
, // segment_flags_set
4582 elfcpp::PF(0), // segment_flags_clear
4585 elfcpp::STT_NOTYPE
, // type
4586 elfcpp::STB_GLOBAL
, // binding
4587 elfcpp::STV_HIDDEN
, // visibility
4589 Symbol::SEGMENT_START
, // offset_from_base
4594 symtab
->define_symbols(layout
, 2, syms
,
4595 layout
->script_options()->saw_sections_clause());
4599 // For x32, we need to handle PC-relative relocations using full 64-bit
4600 // arithmetic, so that we can detect relocation overflows properly.
4601 // This class overrides the pcrela32_check methods from the defaults in
4602 // Relocate_functions in reloc.h.
4605 class X86_64_relocate_functions
: public Relocate_functions
<size
, false>
4608 typedef Relocate_functions
<size
, false> Base
;
4610 // Do a simple PC relative relocation with the addend in the
4612 static inline typename
Base::Reloc_status
4613 pcrela32_check(unsigned char* view
,
4614 typename
elfcpp::Elf_types
<64>::Elf_Addr value
,
4615 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
4616 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
4618 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
4619 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
4620 value
= value
+ addend
- address
;
4621 elfcpp::Swap
<32, false>::writeval(wv
, value
);
4622 return (Bits
<32>::has_overflow(value
)
4623 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
4626 // Do a simple PC relative relocation with a Symbol_value with the
4627 // addend in the relocation.
4628 static inline typename
Base::Reloc_status
4629 pcrela32_check(unsigned char* view
,
4630 const Sized_relobj_file
<size
, false>* object
,
4631 const Symbol_value
<size
>* psymval
,
4632 typename
elfcpp::Elf_types
<64>::Elf_Swxword addend
,
4633 typename
elfcpp::Elf_types
<64>::Elf_Addr address
)
4635 typedef typename
elfcpp::Swap
<32, false>::Valtype Valtype
;
4636 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
4637 typename
elfcpp::Elf_types
<64>::Elf_Addr value
;
4639 value
= psymval
->value(object
, addend
);
4642 // For negative addends, get the symbol value without
4643 // the addend, then add the addend using 64-bit arithmetic.
4644 value
= psymval
->value(object
, 0);
4648 elfcpp::Swap
<32, false>::writeval(wv
, value
);
4649 return (Bits
<32>::has_overflow(value
)
4650 ? Base::RELOC_OVERFLOW
: Base::RELOC_OK
);
4654 // Perform a relocation.
4658 Target_x86_64
<size
>::Relocate::relocate(
4659 const Relocate_info
<size
, false>* relinfo
,
4661 Target_x86_64
<size
>* target
,
4664 const unsigned char* preloc
,
4665 const Sized_symbol
<size
>* gsym
,
4666 const Symbol_value
<size
>* psymval
,
4667 unsigned char* view
,
4668 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
4669 section_size_type view_size
)
4671 typedef X86_64_relocate_functions
<size
> Reloc_funcs
;
4672 const elfcpp::Rela
<size
, false> rela(preloc
);
4673 unsigned int r_type
= elfcpp::elf_r_type
<size
>(rela
.get_r_info());
4675 if (this->skip_call_tls_get_addr_
)
4677 if ((r_type
!= elfcpp::R_X86_64_PLT32
4678 && r_type
!= elfcpp::R_X86_64_GOTPCREL
4679 && r_type
!= elfcpp::R_X86_64_GOTPCRELX
4680 && r_type
!= elfcpp::R_X86_64_PLT32_BND
4681 && r_type
!= elfcpp::R_X86_64_PC32_BND
4682 && r_type
!= elfcpp::R_X86_64_PC32
)
4684 || strcmp(gsym
->name(), "__tls_get_addr") != 0)
4686 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4687 _("missing expected TLS relocation"));
4688 this->skip_call_tls_get_addr_
= false;
4692 this->skip_call_tls_get_addr_
= false;
4700 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
4702 // Pick the value to use for symbols defined in the PLT.
4703 Symbol_value
<size
> symval
;
4705 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
4707 symval
.set_output_value(target
->plt_address_for_global(gsym
));
4710 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
4712 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4713 if (object
->local_has_plt_offset(r_sym
))
4715 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
4720 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
4722 // Get the GOT offset if needed.
4723 // The GOT pointer points to the end of the GOT section.
4724 // We need to subtract the size of the GOT section to get
4725 // the actual offset to use in the relocation.
4726 bool have_got_offset
= false;
4727 // Since the actual offset is always negative, we use signed int to
4728 // support 64-bit GOT relocations.
4732 case elfcpp::R_X86_64_GOT32
:
4733 case elfcpp::R_X86_64_GOT64
:
4734 case elfcpp::R_X86_64_GOTPLT64
:
4735 case elfcpp::R_X86_64_GOTPCREL64
:
4738 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
4739 got_offset
= gsym
->got_offset(GOT_TYPE_STANDARD
) - target
->got_size();
4743 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4744 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
4745 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
4746 - target
->got_size());
4748 have_got_offset
= true;
4755 typename
Reloc_funcs::Reloc_status rstatus
= Reloc_funcs::RELOC_OK
;
4759 case elfcpp::R_X86_64_NONE
:
4760 case elfcpp::R_X86_64_GNU_VTINHERIT
:
4761 case elfcpp::R_X86_64_GNU_VTENTRY
:
4764 case elfcpp::R_X86_64_64
:
4765 Reloc_funcs::rela64(view
, object
, psymval
, addend
);
4768 case elfcpp::R_X86_64_PC64
:
4769 Reloc_funcs::pcrela64(view
, object
, psymval
, addend
,
4773 case elfcpp::R_X86_64_32
:
4774 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
4775 Reloc_funcs::CHECK_UNSIGNED
);
4778 case elfcpp::R_X86_64_32S
:
4779 rstatus
= Reloc_funcs::rela32_check(view
, object
, psymval
, addend
,
4780 Reloc_funcs::CHECK_SIGNED
);
4783 case elfcpp::R_X86_64_PC32
:
4784 case elfcpp::R_X86_64_PC32_BND
:
4785 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
4789 case elfcpp::R_X86_64_16
:
4790 Reloc_funcs::rela16(view
, object
, psymval
, addend
);
4793 case elfcpp::R_X86_64_PC16
:
4794 Reloc_funcs::pcrela16(view
, object
, psymval
, addend
, address
);
4797 case elfcpp::R_X86_64_8
:
4798 Reloc_funcs::rela8(view
, object
, psymval
, addend
);
4801 case elfcpp::R_X86_64_PC8
:
4802 Reloc_funcs::pcrela8(view
, object
, psymval
, addend
, address
);
4805 case elfcpp::R_X86_64_PLT32
:
4806 case elfcpp::R_X86_64_PLT32_BND
:
4807 gold_assert(gsym
== NULL
4808 || gsym
->has_plt_offset()
4809 || gsym
->final_value_is_known()
4810 || (gsym
->is_defined()
4811 && !gsym
->is_from_dynobj()
4812 && !gsym
->is_preemptible()));
4813 // Note: while this code looks the same as for R_X86_64_PC32, it
4814 // behaves differently because psymval was set to point to
4815 // the PLT entry, rather than the symbol, in Scan::global().
4816 rstatus
= Reloc_funcs::pcrela32_check(view
, object
, psymval
, addend
,
4820 case elfcpp::R_X86_64_PLTOFF64
:
4823 gold_assert(gsym
->has_plt_offset()
4824 || gsym
->final_value_is_known());
4825 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
;
4826 // This is the address of GLOBAL_OFFSET_TABLE.
4827 got_address
= target
->got_plt_section()->address();
4828 Reloc_funcs::rela64(view
, object
, psymval
, addend
- got_address
);
4832 case elfcpp::R_X86_64_GOT32
:
4833 gold_assert(have_got_offset
);
4834 Reloc_funcs::rela32(view
, got_offset
, addend
);
4837 case elfcpp::R_X86_64_GOTPC32
:
4840 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4841 value
= target
->got_plt_section()->address();
4842 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
4846 case elfcpp::R_X86_64_GOT64
:
4847 case elfcpp::R_X86_64_GOTPLT64
:
4848 // R_X86_64_GOTPLT64 is obsolete and treated the same as
4850 gold_assert(have_got_offset
);
4851 Reloc_funcs::rela64(view
, got_offset
, addend
);
4854 case elfcpp::R_X86_64_GOTPC64
:
4857 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4858 value
= target
->got_plt_section()->address();
4859 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
4863 case elfcpp::R_X86_64_GOTOFF64
:
4865 typename
elfcpp::Elf_types
<size
>::Elf_Addr reladdr
;
4866 reladdr
= target
->got_plt_section()->address();
4867 Reloc_funcs::pcrela64(view
, object
, psymval
, addend
, reladdr
);
4871 case elfcpp::R_X86_64_GOTPCREL
:
4872 case elfcpp::R_X86_64_GOTPCRELX
:
4873 case elfcpp::R_X86_64_REX_GOTPCRELX
:
4876 // mov foo@GOTPCREL(%rip), %reg
4877 // to lea foo(%rip), %reg.
4879 if (!parameters
->incremental()
4881 && rela
.get_r_offset() >= 2
4883 && !psymval
->is_ifunc_symbol())
4885 && rela
.get_r_offset() >= 2
4886 && Target_x86_64
<size
>::can_convert_mov_to_lea(gsym
, r_type
,
4890 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
4893 // callq *foo@GOTPCRELX(%rip) to
4895 // and jmpq *foo@GOTPCRELX(%rip) to
4898 else if (!parameters
->incremental()
4900 && rela
.get_r_offset() >= 2
4901 && Target_x86_64
<size
>::can_convert_callq_to_direct(gsym
,
4905 if (view
[-1] == 0x15)
4907 // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4908 // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
4911 // Convert GOTPCRELX to 32-bit pc relative reloc.
4912 Reloc_funcs::pcrela32(view
, object
, psymval
, addend
, address
);
4916 // Convert jmpq *foo@GOTPCRELX(%rip) to
4919 // The opcode of direct jmpq is 0xe9.
4921 // The opcode of nop is 0x90.
4923 // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
4924 // relative and since the instruction following the jmpq is now
4925 // the nop, offset the address by 1 byte. The start of the
4926 // relocation also moves ahead by 1 byte.
4927 Reloc_funcs::pcrela32(&view
[-1], object
, psymval
, addend
,
4935 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
4936 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
4937 - target
->got_size());
4941 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
4942 gold_assert(object
->local_has_got_offset(r_sym
,
4943 GOT_TYPE_STANDARD
));
4944 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
4945 - target
->got_size());
4947 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4948 value
= target
->got_plt_section()->address() + got_offset
;
4949 Reloc_funcs::pcrela32_check(view
, value
, addend
, address
);
4954 case elfcpp::R_X86_64_GOTPCREL64
:
4956 gold_assert(have_got_offset
);
4957 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
4958 value
= target
->got_plt_section()->address() + got_offset
;
4959 Reloc_funcs::pcrela64(view
, value
, addend
, address
);
4963 case elfcpp::R_X86_64_COPY
:
4964 case elfcpp::R_X86_64_GLOB_DAT
:
4965 case elfcpp::R_X86_64_JUMP_SLOT
:
4966 case elfcpp::R_X86_64_RELATIVE
:
4967 case elfcpp::R_X86_64_IRELATIVE
:
4968 // These are outstanding tls relocs, which are unexpected when linking
4969 case elfcpp::R_X86_64_TPOFF64
:
4970 case elfcpp::R_X86_64_DTPMOD64
:
4971 case elfcpp::R_X86_64_TLSDESC
:
4972 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4973 _("unexpected reloc %u in object file"),
4977 // These are initial tls relocs, which are expected when linking
4978 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
4979 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
4980 case elfcpp::R_X86_64_TLSDESC_CALL
:
4981 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
4982 case elfcpp::R_X86_64_DTPOFF32
:
4983 case elfcpp::R_X86_64_DTPOFF64
:
4984 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
4985 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
4986 this->relocate_tls(relinfo
, target
, relnum
, rela
, r_type
, gsym
, psymval
,
4987 view
, address
, view_size
);
4990 case elfcpp::R_X86_64_SIZE32
:
4991 case elfcpp::R_X86_64_SIZE64
:
4993 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
4994 _("unsupported reloc %u"),
4999 if (rstatus
== Reloc_funcs::RELOC_OVERFLOW
)
5003 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5004 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5005 _("relocation overflow: "
5006 "reference to local symbol %u in %s"),
5007 r_sym
, object
->name().c_str());
5009 else if (gsym
->is_defined() && gsym
->source() == Symbol::FROM_OBJECT
)
5011 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5012 _("relocation overflow: "
5013 "reference to '%s' defined in %s"),
5015 gsym
->object()->name().c_str());
5019 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5020 _("relocation overflow: reference to '%s'"),
5028 // Perform a TLS relocation.
5032 Target_x86_64
<size
>::Relocate::relocate_tls(
5033 const Relocate_info
<size
, false>* relinfo
,
5034 Target_x86_64
<size
>* target
,
5036 const elfcpp::Rela
<size
, false>& rela
,
5037 unsigned int r_type
,
5038 const Sized_symbol
<size
>* gsym
,
5039 const Symbol_value
<size
>* psymval
,
5040 unsigned char* view
,
5041 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5042 section_size_type view_size
)
5044 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
5046 const Sized_relobj_file
<size
, false>* object
= relinfo
->object
;
5047 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
5048 elfcpp::Shdr
<size
, false> data_shdr(relinfo
->data_shdr
);
5049 bool is_executable
= (data_shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0;
5051 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
= psymval
->value(relinfo
->object
, 0);
5053 const bool is_final
= (gsym
== NULL
5054 ? !parameters
->options().shared()
5055 : gsym
->final_value_is_known());
5056 tls::Tls_optimization optimized_type
5057 = Target_x86_64
<size
>::optimize_tls_reloc(is_final
, r_type
);
5060 case elfcpp::R_X86_64_TLSGD
: // Global-dynamic
5061 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
5063 // If this code sequence is used in a non-executable section,
5064 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
5065 // on the assumption that it's being used by itself in a debug
5066 // section. Therefore, in the unlikely event that the code
5067 // sequence appears in a non-executable section, we simply
5068 // leave it unoptimized.
5069 optimized_type
= tls::TLSOPT_NONE
;
5071 if (optimized_type
== tls::TLSOPT_TO_LE
)
5073 if (tls_segment
== NULL
)
5075 gold_assert(parameters
->errors()->error_count() > 0
5076 || issue_undefined_symbol_error(gsym
));
5079 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
5080 rela
, r_type
, value
, view
,
5086 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
5087 ? GOT_TYPE_TLS_OFFSET
5088 : GOT_TYPE_TLS_PAIR
);
5089 unsigned int got_offset
;
5092 gold_assert(gsym
->has_got_offset(got_type
));
5093 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
5097 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5098 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
5099 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
5100 - target
->got_size());
5102 if (optimized_type
== tls::TLSOPT_TO_IE
)
5104 value
= target
->got_plt_section()->address() + got_offset
;
5105 this->tls_gd_to_ie(relinfo
, relnum
, rela
, r_type
,
5106 value
, view
, address
, view_size
);
5109 else if (optimized_type
== tls::TLSOPT_NONE
)
5111 // Relocate the field with the offset of the pair of GOT
5113 value
= target
->got_plt_section()->address() + got_offset
;
5114 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5119 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5120 _("unsupported reloc %u"), r_type
);
5123 case elfcpp::R_X86_64_GOTPC32_TLSDESC
: // Global-dynamic (from ~oliva url)
5124 case elfcpp::R_X86_64_TLSDESC_CALL
:
5125 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
5127 // See above comment for R_X86_64_TLSGD.
5128 optimized_type
= tls::TLSOPT_NONE
;
5130 if (optimized_type
== tls::TLSOPT_TO_LE
)
5132 if (tls_segment
== NULL
)
5134 gold_assert(parameters
->errors()->error_count() > 0
5135 || issue_undefined_symbol_error(gsym
));
5138 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
5139 rela
, r_type
, value
, view
,
5145 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
5146 ? GOT_TYPE_TLS_OFFSET
5147 : GOT_TYPE_TLS_DESC
);
5148 unsigned int got_offset
= 0;
5149 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
5150 && optimized_type
== tls::TLSOPT_NONE
)
5152 // We created GOT entries in the .got.tlsdesc portion of
5153 // the .got.plt section, but the offset stored in the
5154 // symbol is the offset within .got.tlsdesc.
5155 got_offset
= (target
->got_size()
5156 + target
->got_plt_section()->data_size());
5160 gold_assert(gsym
->has_got_offset(got_type
));
5161 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
5165 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5166 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
5167 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
5168 - target
->got_size());
5170 if (optimized_type
== tls::TLSOPT_TO_IE
)
5172 value
= target
->got_plt_section()->address() + got_offset
;
5173 this->tls_desc_gd_to_ie(relinfo
, relnum
,
5174 rela
, r_type
, value
, view
, address
,
5178 else if (optimized_type
== tls::TLSOPT_NONE
)
5180 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
5182 // Relocate the field with the offset of the pair of GOT
5184 value
= target
->got_plt_section()->address() + got_offset
;
5185 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5191 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5192 _("unsupported reloc %u"), r_type
);
5195 case elfcpp::R_X86_64_TLSLD
: // Local-dynamic
5196 if (!is_executable
&& optimized_type
== tls::TLSOPT_TO_LE
)
5198 // See above comment for R_X86_64_TLSGD.
5199 optimized_type
= tls::TLSOPT_NONE
;
5201 if (optimized_type
== tls::TLSOPT_TO_LE
)
5203 if (tls_segment
== NULL
)
5205 gold_assert(parameters
->errors()->error_count() > 0
5206 || issue_undefined_symbol_error(gsym
));
5209 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rela
, r_type
,
5210 value
, view
, view_size
);
5213 else if (optimized_type
== tls::TLSOPT_NONE
)
5215 // Relocate the field with the offset of the GOT entry for
5216 // the module index.
5217 unsigned int got_offset
;
5218 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
5219 - target
->got_size());
5220 value
= target
->got_plt_section()->address() + got_offset
;
5221 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5225 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5226 _("unsupported reloc %u"), r_type
);
5229 case elfcpp::R_X86_64_DTPOFF32
:
5230 // This relocation type is used in debugging information.
5231 // In that case we need to not optimize the value. If the
5232 // section is not executable, then we assume we should not
5233 // optimize this reloc. See comments above for R_X86_64_TLSGD,
5234 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
5236 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
5238 if (tls_segment
== NULL
)
5240 gold_assert(parameters
->errors()->error_count() > 0
5241 || issue_undefined_symbol_error(gsym
));
5244 value
-= tls_segment
->memsz();
5246 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
5249 case elfcpp::R_X86_64_DTPOFF64
:
5250 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
5251 if (optimized_type
== tls::TLSOPT_TO_LE
&& is_executable
)
5253 if (tls_segment
== NULL
)
5255 gold_assert(parameters
->errors()->error_count() > 0
5256 || issue_undefined_symbol_error(gsym
));
5259 value
-= tls_segment
->memsz();
5261 Relocate_functions
<size
, false>::rela64(view
, value
, addend
);
5264 case elfcpp::R_X86_64_GOTTPOFF
: // Initial-exec
5266 && gsym
->is_undefined()
5267 && parameters
->options().output_is_executable())
5269 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
5271 r_type
, value
, view
,
5275 else if (optimized_type
== tls::TLSOPT_TO_LE
)
5277 if (tls_segment
== NULL
)
5279 gold_assert(parameters
->errors()->error_count() > 0
5280 || issue_undefined_symbol_error(gsym
));
5283 Target_x86_64
<size
>::Relocate::tls_ie_to_le(relinfo
, relnum
,
5285 r_type
, value
, view
,
5289 else if (optimized_type
== tls::TLSOPT_NONE
)
5291 // Relocate the field with the offset of the GOT entry for
5292 // the tp-relative offset of the symbol.
5293 unsigned int got_offset
;
5296 gold_assert(gsym
->has_got_offset(GOT_TYPE_TLS_OFFSET
));
5297 got_offset
= (gsym
->got_offset(GOT_TYPE_TLS_OFFSET
)
5298 - target
->got_size());
5302 unsigned int r_sym
= elfcpp::elf_r_sym
<size
>(rela
.get_r_info());
5303 gold_assert(object
->local_has_got_offset(r_sym
,
5304 GOT_TYPE_TLS_OFFSET
));
5305 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_TLS_OFFSET
)
5306 - target
->got_size());
5308 value
= target
->got_plt_section()->address() + got_offset
;
5309 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
,
5313 gold_error_at_location(relinfo
, relnum
, rela
.get_r_offset(),
5314 _("unsupported reloc type %u"),
5318 case elfcpp::R_X86_64_TPOFF32
: // Local-exec
5319 if (tls_segment
== NULL
)
5321 gold_assert(parameters
->errors()->error_count() > 0
5322 || issue_undefined_symbol_error(gsym
));
5325 value
-= tls_segment
->memsz();
5326 Relocate_functions
<size
, false>::rela32(view
, value
, addend
);
5331 // Do a relocation in which we convert a TLS General-Dynamic to an
5336 Target_x86_64
<size
>::Relocate::tls_gd_to_ie(
5337 const Relocate_info
<size
, false>* relinfo
,
5339 const elfcpp::Rela
<size
, false>& rela
,
5341 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5342 unsigned char* view
,
5343 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5344 section_size_type view_size
)
5347 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5348 // .word 0x6666; rex64; call __tls_get_addr@PLT
5349 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5350 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5351 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5352 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5354 // leaq foo@tlsgd(%rip),%rdi;
5355 // .word 0x6666; rex64; call __tls_get_addr@PLT
5356 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5357 // leaq foo@tlsgd(%rip),%rdi;
5358 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5359 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5361 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
5362 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5363 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0
5364 || memcmp(view
+ 4, "\x66\x48\xff", 3) == 0));
5368 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5370 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5371 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
5372 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5377 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5379 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5380 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
5381 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5385 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
5386 Relocate_functions
<size
, false>::pcrela32(view
+ 8, value
, addend
- 8,
5389 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5391 this->skip_call_tls_get_addr_
= true;
5394 // Do a relocation in which we convert a TLS General-Dynamic to a
5399 Target_x86_64
<size
>::Relocate::tls_gd_to_le(
5400 const Relocate_info
<size
, false>* relinfo
,
5402 Output_segment
* tls_segment
,
5403 const elfcpp::Rela
<size
, false>& rela
,
5405 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5406 unsigned char* view
,
5407 section_size_type view_size
)
5410 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5411 // .word 0x6666; rex64; call __tls_get_addr@PLT
5412 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5413 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5414 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5415 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5417 // leaq foo@tlsgd(%rip),%rdi;
5418 // .word 0x6666; rex64; call __tls_get_addr@PLT
5419 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5420 // leaq foo@tlsgd(%rip),%rdi;
5421 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5422 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5424 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 12);
5425 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5426 (memcmp(view
+ 4, "\x66\x66\x48\xe8", 4) == 0
5427 || memcmp(view
+ 4, "\x66\x48\xff", 3) == 0));
5431 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5433 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5434 (memcmp(view
- 4, "\x66\x48\x8d\x3d", 4) == 0));
5435 memcpy(view
- 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5440 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
,
5442 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5443 (memcmp(view
- 3, "\x48\x8d\x3d", 3) == 0));
5445 memcpy(view
- 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5449 value
-= tls_segment
->memsz();
5450 Relocate_functions
<size
, false>::rela32(view
+ 8, value
, 0);
5452 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5454 this->skip_call_tls_get_addr_
= true;
5457 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
5461 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_ie(
5462 const Relocate_info
<size
, false>* relinfo
,
5464 const elfcpp::Rela
<size
, false>& rela
,
5465 unsigned int r_type
,
5466 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5467 unsigned char* view
,
5468 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5469 section_size_type view_size
)
5471 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
5473 // leaq foo@tlsdesc(%rip), %rax
5474 // ==> movq foo@gottpoff(%rip), %rax
5475 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5476 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
5477 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5478 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
5480 const elfcpp::Elf_Xword addend
= rela
.get_r_addend();
5481 Relocate_functions
<size
, false>::pcrela32(view
, value
, addend
, address
);
5485 // call *foo@tlscall(%rax)
5487 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
5488 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
5489 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5490 view
[0] == 0xff && view
[1] == 0x10);
5496 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
5500 Target_x86_64
<size
>::Relocate::tls_desc_gd_to_le(
5501 const Relocate_info
<size
, false>* relinfo
,
5503 Output_segment
* tls_segment
,
5504 const elfcpp::Rela
<size
, false>& rela
,
5505 unsigned int r_type
,
5506 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5507 unsigned char* view
,
5508 section_size_type view_size
)
5510 if (r_type
== elfcpp::R_X86_64_GOTPC32_TLSDESC
)
5512 // leaq foo@tlsdesc(%rip), %rax
5513 // ==> movq foo@tpoff, %rax
5514 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5515 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
5516 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5517 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x05);
5520 value
-= tls_segment
->memsz();
5521 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
5525 // call *foo@tlscall(%rax)
5527 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC_CALL
);
5528 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 2);
5529 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5530 view
[0] == 0xff && view
[1] == 0x10);
5538 Target_x86_64
<size
>::Relocate::tls_ld_to_le(
5539 const Relocate_info
<size
, false>* relinfo
,
5542 const elfcpp::Rela
<size
, false>& rela
,
5544 typename
elfcpp::Elf_types
<size
>::Elf_Addr
,
5545 unsigned char* view
,
5546 section_size_type view_size
)
5548 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
5550 // ... leq foo@dtpoff(%rax),%reg
5551 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5553 // ... leq foo@dtpoff(%rax),%reg
5554 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5555 // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
5557 // ... leq foo@dtpoff(%rax),%reg
5558 // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5560 // ... leq foo@dtpoff(%rax),%reg
5561 // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5563 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5564 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 9);
5566 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5567 view
[-3] == 0x48 && view
[-2] == 0x8d && view
[-1] == 0x3d);
5569 tls::check_tls(relinfo
, relnum
, rela
.get_r_offset(),
5570 view
[4] == 0xe8 || view
[4] == 0xff);
5572 if (view
[4] == 0xe8)
5575 memcpy(view
- 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
5577 memcpy(view
- 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
5582 memcpy(view
- 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
5585 memcpy(view
- 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
5589 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5591 this->skip_call_tls_get_addr_
= true;
5594 // Do a relocation in which we convert a TLS Initial-Exec to a
5599 Target_x86_64
<size
>::Relocate::tls_ie_to_le(
5600 const Relocate_info
<size
, false>* relinfo
,
5602 Output_segment
* tls_segment
,
5603 const elfcpp::Rela
<size
, false>& rela
,
5605 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
5606 unsigned char* view
,
5607 section_size_type view_size
)
5609 // We need to examine the opcodes to figure out which instruction we
5612 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
5613 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
5615 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, -3);
5616 tls::check_range(relinfo
, relnum
, rela
.get_r_offset(), view_size
, 4);
5618 unsigned char op1
= view
[-3];
5619 unsigned char op2
= view
[-2];
5620 unsigned char op3
= view
[-1];
5621 unsigned char reg
= op3
>> 3;
5628 else if (size
== 32 && op1
== 0x44)
5631 view
[-1] = 0xc0 | reg
;
5635 // Special handling for %rsp.
5638 else if (size
== 32 && op1
== 0x44)
5641 view
[-1] = 0xc0 | reg
;
5648 else if (size
== 32 && op1
== 0x44)
5651 view
[-1] = 0x80 | reg
| (reg
<< 3);
5654 if (tls_segment
!= NULL
)
5655 value
-= tls_segment
->memsz();
5656 Relocate_functions
<size
, false>::rela32(view
, value
, 0);
5659 // Relocate section data.
5663 Target_x86_64
<size
>::relocate_section(
5664 const Relocate_info
<size
, false>* relinfo
,
5665 unsigned int sh_type
,
5666 const unsigned char* prelocs
,
5668 Output_section
* output_section
,
5669 bool needs_special_offset_handling
,
5670 unsigned char* view
,
5671 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5672 section_size_type view_size
,
5673 const Reloc_symbol_changes
* reloc_symbol_changes
)
5675 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5678 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5680 gold::relocate_section
<size
, false, Target_x86_64
<size
>, Relocate
,
5681 gold::Default_comdat_behavior
, Classify_reloc
>(
5687 needs_special_offset_handling
,
5691 reloc_symbol_changes
);
5694 // Apply an incremental relocation. Incremental relocations always refer
5695 // to global symbols.
5699 Target_x86_64
<size
>::apply_relocation(
5700 const Relocate_info
<size
, false>* relinfo
,
5701 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
5702 unsigned int r_type
,
5703 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
5705 unsigned char* view
,
5706 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
5707 section_size_type view_size
)
5709 gold::apply_relocation
<size
, false, Target_x86_64
<size
>,
5710 typename Target_x86_64
<size
>::Relocate
>(
5722 // Scan the relocs during a relocatable link.
5726 Target_x86_64
<size
>::scan_relocatable_relocs(
5727 Symbol_table
* symtab
,
5729 Sized_relobj_file
<size
, false>* object
,
5730 unsigned int data_shndx
,
5731 unsigned int sh_type
,
5732 const unsigned char* prelocs
,
5734 Output_section
* output_section
,
5735 bool needs_special_offset_handling
,
5736 size_t local_symbol_count
,
5737 const unsigned char* plocal_symbols
,
5738 Relocatable_relocs
* rr
)
5740 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5742 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
5743 Scan_relocatable_relocs
;
5745 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5747 gold::scan_relocatable_relocs
<size
, false, Scan_relocatable_relocs
>(
5755 needs_special_offset_handling
,
5761 // Scan the relocs for --emit-relocs.
5765 Target_x86_64
<size
>::emit_relocs_scan(
5766 Symbol_table
* symtab
,
5768 Sized_relobj_file
<size
, false>* object
,
5769 unsigned int data_shndx
,
5770 unsigned int sh_type
,
5771 const unsigned char* prelocs
,
5773 Output_section
* output_section
,
5774 bool needs_special_offset_handling
,
5775 size_t local_symbol_count
,
5776 const unsigned char* plocal_syms
,
5777 Relocatable_relocs
* rr
)
5779 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5781 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
5782 Emit_relocs_strategy
;
5784 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5786 gold::scan_relocatable_relocs
<size
, false, Emit_relocs_strategy
>(
5794 needs_special_offset_handling
,
5800 // Relocate a section during a relocatable link.
5804 Target_x86_64
<size
>::relocate_relocs(
5805 const Relocate_info
<size
, false>* relinfo
,
5806 unsigned int sh_type
,
5807 const unsigned char* prelocs
,
5809 Output_section
* output_section
,
5810 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
5811 unsigned char* view
,
5812 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
5813 section_size_type view_size
,
5814 unsigned char* reloc_view
,
5815 section_size_type reloc_view_size
)
5817 typedef gold::Default_classify_reloc
<elfcpp::SHT_RELA
, size
, false>
5820 gold_assert(sh_type
== elfcpp::SHT_RELA
);
5822 gold::relocate_relocs
<size
, false, Classify_reloc
>(
5827 offset_in_output_section
,
5835 // Return the value to use for a dynamic which requires special
5836 // treatment. This is how we support equality comparisons of function
5837 // pointers across shared library boundaries, as described in the
5838 // processor specific ABI supplement.
5842 Target_x86_64
<size
>::do_dynsym_value(const Symbol
* gsym
) const
5844 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
5845 return this->plt_address_for_global(gsym
);
5848 // Return a string used to fill a code section with nops to take up
5849 // the specified length.
5853 Target_x86_64
<size
>::do_code_fill(section_size_type length
) const
5857 // Build a jmpq instruction to skip over the bytes.
5858 unsigned char jmp
[5];
5860 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
5861 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
5862 + std::string(length
- 5, static_cast<char>(0x90)));
5865 // Nop sequences of various lengths.
5866 const char nop1
[1] = { '\x90' }; // nop
5867 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
5868 const char nop3
[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5869 const char nop4
[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
5871 const char nop5
[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
5873 const char nop6
[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
5874 '\x44', '\x00', '\x00' };
5875 const char nop7
[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
5876 '\x00', '\x00', '\x00',
5878 const char nop8
[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
5879 '\x00', '\x00', '\x00',
5881 const char nop9
[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
5882 '\x84', '\x00', '\x00',
5883 '\x00', '\x00', '\x00' };
5884 const char nop10
[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5885 '\x1f', '\x84', '\x00',
5886 '\x00', '\x00', '\x00',
5888 const char nop11
[11] = { '\x66', '\x66', '\x2e', // data16
5889 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5890 '\x00', '\x00', '\x00',
5892 const char nop12
[12] = { '\x66', '\x66', '\x66', // data16; data16
5893 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5894 '\x84', '\x00', '\x00',
5895 '\x00', '\x00', '\x00' };
5896 const char nop13
[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5897 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5898 '\x1f', '\x84', '\x00',
5899 '\x00', '\x00', '\x00',
5901 const char nop14
[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5902 '\x66', '\x66', '\x2e', // data16
5903 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5904 '\x00', '\x00', '\x00',
5906 const char nop15
[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5907 '\x66', '\x66', '\x66', // data16; data16
5908 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5909 '\x84', '\x00', '\x00',
5910 '\x00', '\x00', '\x00' };
5912 const char* nops
[16] = {
5914 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
5915 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
5918 return std::string(nops
[length
], length
);
5921 // Return the addend to use for a target specific relocation. The
5922 // only target specific relocation is R_X86_64_TLSDESC for a local
5923 // symbol. We want to set the addend is the offset of the local
5924 // symbol in the TLS segment.
5928 Target_x86_64
<size
>::do_reloc_addend(void* arg
, unsigned int r_type
,
5931 gold_assert(r_type
== elfcpp::R_X86_64_TLSDESC
);
5932 uintptr_t intarg
= reinterpret_cast<uintptr_t>(arg
);
5933 gold_assert(intarg
< this->tlsdesc_reloc_info_
.size());
5934 const Tlsdesc_info
& ti(this->tlsdesc_reloc_info_
[intarg
]);
5935 const Symbol_value
<size
>* psymval
= ti
.object
->local_symbol(ti
.r_sym
);
5936 gold_assert(psymval
->is_tls_symbol());
5937 // The value of a TLS symbol is the offset in the TLS segment.
5938 return psymval
->value(ti
.object
, 0);
5941 // Return the value to use for the base of a DW_EH_PE_datarel offset
5942 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
5943 // assembler can not write out the difference between two labels in
5944 // different sections, so instead of using a pc-relative value they
5945 // use an offset from the GOT.
5949 Target_x86_64
<size
>::do_ehframe_datarel_base() const
5951 gold_assert(this->global_offset_table_
!= NULL
);
5952 Symbol
* sym
= this->global_offset_table_
;
5953 Sized_symbol
<size
>* ssym
= static_cast<Sized_symbol
<size
>*>(sym
);
5954 return ssym
->value();
5957 // FNOFFSET in section SHNDX in OBJECT is the start of a function
5958 // compiled with -fsplit-stack. The function calls non-split-stack
5959 // code. We have to change the function so that it always ensures
5960 // that it has enough stack space to run some random function.
5962 static const unsigned char cmp_insn_32
[] = { 0x64, 0x3b, 0x24, 0x25 };
5963 static const unsigned char lea_r10_insn_32
[] = { 0x44, 0x8d, 0x94, 0x24 };
5964 static const unsigned char lea_r11_insn_32
[] = { 0x44, 0x8d, 0x9c, 0x24 };
5966 static const unsigned char cmp_insn_64
[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
5967 static const unsigned char lea_r10_insn_64
[] = { 0x4c, 0x8d, 0x94, 0x24 };
5968 static const unsigned char lea_r11_insn_64
[] = { 0x4c, 0x8d, 0x9c, 0x24 };
5972 Target_x86_64
<size
>::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
5973 section_offset_type fnoffset
,
5974 section_size_type fnsize
,
5975 const unsigned char*,
5977 unsigned char* view
,
5978 section_size_type view_size
,
5980 std::string
* to
) const
5982 const char* const cmp_insn
= reinterpret_cast<const char*>
5983 (size
== 32 ? cmp_insn_32
: cmp_insn_64
);
5984 const char* const lea_r10_insn
= reinterpret_cast<const char*>
5985 (size
== 32 ? lea_r10_insn_32
: lea_r10_insn_64
);
5986 const char* const lea_r11_insn
= reinterpret_cast<const char*>
5987 (size
== 32 ? lea_r11_insn_32
: lea_r11_insn_64
);
5989 const size_t cmp_insn_len
=
5990 (size
== 32 ? sizeof(cmp_insn_32
) : sizeof(cmp_insn_64
));
5991 const size_t lea_r10_insn_len
=
5992 (size
== 32 ? sizeof(lea_r10_insn_32
) : sizeof(lea_r10_insn_64
));
5993 const size_t lea_r11_insn_len
=
5994 (size
== 32 ? sizeof(lea_r11_insn_32
) : sizeof(lea_r11_insn_64
));
5995 const size_t nop_len
= (size
== 32 ? 7 : 8);
5997 // The function starts with a comparison of the stack pointer and a
5998 // field in the TCB. This is followed by a jump.
6001 if (this->match_view(view
, view_size
, fnoffset
, cmp_insn
, cmp_insn_len
)
6002 && fnsize
> nop_len
+ 1)
6004 // We will call __morestack if the carry flag is set after this
6005 // comparison. We turn the comparison into an stc instruction
6007 view
[fnoffset
] = '\xf9';
6008 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, nop_len
);
6010 // lea NN(%rsp),%r10
6011 // lea NN(%rsp),%r11
6012 else if ((this->match_view(view
, view_size
, fnoffset
,
6013 lea_r10_insn
, lea_r10_insn_len
)
6014 || this->match_view(view
, view_size
, fnoffset
,
6015 lea_r11_insn
, lea_r11_insn_len
))
6018 // This is loading an offset from the stack pointer for a
6019 // comparison. The offset is negative, so we decrease the
6020 // offset by the amount of space we need for the stack. This
6021 // means we will avoid calling __morestack if there happens to
6022 // be plenty of space on the stack already.
6023 unsigned char* pval
= view
+ fnoffset
+ 4;
6024 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
6025 val
-= parameters
->options().split_stack_adjust_size();
6026 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
6030 if (!object
->has_no_split_stack())
6031 object
->error(_("failed to match split-stack sequence at "
6032 "section %u offset %0zx"),
6033 shndx
, static_cast<size_t>(fnoffset
));
6037 // We have to change the function so that it calls
6038 // __morestack_non_split instead of __morestack. The former will
6039 // allocate additional stack space.
6040 *from
= "__morestack";
6041 *to
= "__morestack_non_split";
6044 // The selector for x86_64 object files. Note this is never instantiated
6045 // directly. It's only used in Target_selector_x86_64_nacl, below.
6048 class Target_selector_x86_64
: public Target_selector_freebsd
6051 Target_selector_x86_64()
6052 : Target_selector_freebsd(elfcpp::EM_X86_64
, size
, false,
6054 ? "elf64-x86-64" : "elf32-x86-64"),
6056 ? "elf64-x86-64-freebsd"
6057 : "elf32-x86-64-freebsd"),
6058 (size
== 64 ? "elf_x86_64" : "elf32_x86_64"))
6062 do_instantiate_target()
6063 { return new Target_x86_64
<size
>(); }
6067 // NaCl variant. It uses different PLT contents.
6070 class Output_data_plt_x86_64_nacl
: public Output_data_plt_x86_64
<size
>
6073 Output_data_plt_x86_64_nacl(Layout
* layout
,
6074 Output_data_got
<64, false>* got
,
6075 Output_data_got_plt_x86_64
* got_plt
,
6076 Output_data_space
* got_irelative
)
6077 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
6078 got
, got_plt
, got_irelative
)
6081 Output_data_plt_x86_64_nacl(Layout
* layout
,
6082 Output_data_got
<64, false>* got
,
6083 Output_data_got_plt_x86_64
* got_plt
,
6084 Output_data_space
* got_irelative
,
6085 unsigned int plt_count
)
6086 : Output_data_plt_x86_64
<size
>(layout
, plt_entry_size
,
6087 got
, got_plt
, got_irelative
,
6092 virtual unsigned int
6093 do_get_plt_entry_size() const
6094 { return plt_entry_size
; }
6097 do_add_eh_frame(Layout
* layout
)
6099 layout
->add_eh_frame_for_plt(this,
6100 this->plt_eh_frame_cie
,
6101 this->plt_eh_frame_cie_size
,
6103 plt_eh_frame_fde_size
);
6107 do_fill_first_plt_entry(unsigned char* pov
,
6108 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_addr
,
6109 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_addr
);
6111 virtual unsigned int
6112 do_fill_plt_entry(unsigned char* pov
,
6113 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6114 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6115 unsigned int got_offset
,
6116 unsigned int plt_offset
,
6117 unsigned int plt_index
);
6120 do_fill_tlsdesc_entry(unsigned char* pov
,
6121 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6122 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6123 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
6124 unsigned int tlsdesc_got_offset
,
6125 unsigned int plt_offset
);
6128 // The size of an entry in the PLT.
6129 static const int plt_entry_size
= 64;
6131 // The first entry in the PLT.
6132 static const unsigned char first_plt_entry
[plt_entry_size
];
6134 // Other entries in the PLT for an executable.
6135 static const unsigned char plt_entry
[plt_entry_size
];
6137 // The reserved TLSDESC entry in the PLT for an executable.
6138 static const unsigned char tlsdesc_plt_entry
[plt_entry_size
];
6140 // The .eh_frame unwind information for the PLT.
6141 static const int plt_eh_frame_fde_size
= 32;
6142 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
6146 class Target_x86_64_nacl
: public Target_x86_64
<size
>
6149 Target_x86_64_nacl()
6150 : Target_x86_64
<size
>(&x86_64_nacl_info
)
6153 virtual Output_data_plt_x86_64
<size
>*
6154 do_make_data_plt(Layout
* layout
,
6155 Output_data_got
<64, false>* got
,
6156 Output_data_got_plt_x86_64
* got_plt
,
6157 Output_data_space
* got_irelative
)
6159 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
6163 virtual Output_data_plt_x86_64
<size
>*
6164 do_make_data_plt(Layout
* layout
,
6165 Output_data_got
<64, false>* got
,
6166 Output_data_got_plt_x86_64
* got_plt
,
6167 Output_data_space
* got_irelative
,
6168 unsigned int plt_count
)
6170 return new Output_data_plt_x86_64_nacl
<size
>(layout
, got
, got_plt
,
6176 do_code_fill(section_size_type length
) const;
6179 static const Target::Target_info x86_64_nacl_info
;
6183 const Target::Target_info Target_x86_64_nacl
<64>::x86_64_nacl_info
=
6186 false, // is_big_endian
6187 elfcpp::EM_X86_64
, // machine_code
6188 false, // has_make_symbol
6189 false, // has_resolve
6190 true, // has_code_fill
6191 true, // is_default_stack_executable
6192 true, // can_icf_inline_merge_sections
6194 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
6195 0x20000, // default_text_segment_address
6196 0x10000, // abi_pagesize (overridable by -z max-page-size)
6197 0x10000, // common_pagesize (overridable by -z common-page-size)
6198 true, // isolate_execinstr
6199 0x10000000, // rosegment_gap
6200 elfcpp::SHN_UNDEF
, // small_common_shndx
6201 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
6202 0, // small_common_section_flags
6203 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
6204 NULL
, // attributes_section
6205 NULL
, // attributes_vendor
6206 "_start", // entry_symbol_name
6207 32, // hash_entry_size
6208 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
6212 const Target::Target_info Target_x86_64_nacl
<32>::x86_64_nacl_info
=
6215 false, // is_big_endian
6216 elfcpp::EM_X86_64
, // machine_code
6217 false, // has_make_symbol
6218 false, // has_resolve
6219 true, // has_code_fill
6220 true, // is_default_stack_executable
6221 true, // can_icf_inline_merge_sections
6223 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
6224 0x20000, // default_text_segment_address
6225 0x10000, // abi_pagesize (overridable by -z max-page-size)
6226 0x10000, // common_pagesize (overridable by -z common-page-size)
6227 true, // isolate_execinstr
6228 0x10000000, // rosegment_gap
6229 elfcpp::SHN_UNDEF
, // small_common_shndx
6230 elfcpp::SHN_X86_64_LCOMMON
, // large_common_shndx
6231 0, // small_common_section_flags
6232 elfcpp::SHF_X86_64_LARGE
, // large_common_section_flags
6233 NULL
, // attributes_section
6234 NULL
, // attributes_vendor
6235 "_start", // entry_symbol_name
6236 32, // hash_entry_size
6237 elfcpp::SHT_X86_64_UNWIND
, // unwind_section_type
6240 #define NACLMASK 0xe0 // 32-byte alignment mask.
6242 // The first entry in the PLT.
6246 Output_data_plt_x86_64_nacl
<size
>::first_plt_entry
[plt_entry_size
] =
6248 0xff, 0x35, // pushq contents of memory address
6249 0, 0, 0, 0, // replaced with address of .got + 8
6250 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
6251 0, 0, 0, 0, // replaced with address of .got + 16
6252 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
6253 0x4d, 0x01, 0xfb, // add %r15, %r11
6254 0x41, 0xff, 0xe3, // jmpq *%r11
6256 // 9-byte nop sequence to pad out to the next 32-byte boundary.
6257 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
6259 // 32 bytes of nop to pad out to the standard size
6260 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6261 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6262 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6263 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6264 0x66, // excess data32 prefix
6270 Output_data_plt_x86_64_nacl
<size
>::do_fill_first_plt_entry(
6272 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6273 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
)
6275 memcpy(pov
, first_plt_entry
, plt_entry_size
);
6276 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
6278 - (plt_address
+ 2 + 4)));
6279 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
6281 - (plt_address
+ 9 + 4)));
6284 // Subsequent entries in the PLT.
6288 Output_data_plt_x86_64_nacl
<size
>::plt_entry
[plt_entry_size
] =
6290 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
6291 0, 0, 0, 0, // replaced with address of symbol in .got
6292 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
6293 0x4d, 0x01, 0xfb, // add %r15, %r11
6294 0x41, 0xff, 0xe3, // jmpq *%r11
6296 // 15-byte nop sequence to pad out to the next 32-byte boundary.
6297 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6298 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6300 // Lazy GOT entries point here (32-byte aligned).
6301 0x68, // pushq immediate
6302 0, 0, 0, 0, // replaced with index into relocation table
6303 0xe9, // jmp relative
6304 0, 0, 0, 0, // replaced with offset to start of .plt0
6306 // 22 bytes of nop to pad out to the standard size.
6307 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6308 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6309 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
6314 Output_data_plt_x86_64_nacl
<size
>::do_fill_plt_entry(
6316 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6317 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6318 unsigned int got_offset
,
6319 unsigned int plt_offset
,
6320 unsigned int plt_index
)
6322 memcpy(pov
, plt_entry
, plt_entry_size
);
6323 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 3,
6324 (got_address
+ got_offset
6325 - (plt_address
+ plt_offset
6328 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_index
);
6329 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 38,
6330 - (plt_offset
+ 38 + 4));
6335 // The reserved TLSDESC entry in the PLT.
6339 Output_data_plt_x86_64_nacl
<size
>::tlsdesc_plt_entry
[plt_entry_size
] =
6341 0xff, 0x35, // pushq x(%rip)
6342 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
6343 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
6344 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
6345 0x41, 0x83, 0xe3, NACLMASK
, // and $-32, %r11d
6346 0x4d, 0x01, 0xfb, // add %r15, %r11
6347 0x41, 0xff, 0xe3, // jmpq *%r11
6349 // 41 bytes of nop to pad out to the standard size.
6350 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6351 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6352 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6353 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6354 0x66, 0x66, // excess data32 prefixes
6355 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6360 Output_data_plt_x86_64_nacl
<size
>::do_fill_tlsdesc_entry(
6362 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_address
,
6363 typename
elfcpp::Elf_types
<size
>::Elf_Addr plt_address
,
6364 typename
elfcpp::Elf_types
<size
>::Elf_Addr got_base
,
6365 unsigned int tlsdesc_got_offset
,
6366 unsigned int plt_offset
)
6368 memcpy(pov
, tlsdesc_plt_entry
, plt_entry_size
);
6369 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
6371 - (plt_address
+ plt_offset
6373 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 9,
6375 + tlsdesc_got_offset
6376 - (plt_address
+ plt_offset
6380 // The .eh_frame unwind information for the PLT.
6384 Output_data_plt_x86_64_nacl
<size
>::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
6386 0, 0, 0, 0, // Replaced with offset to .plt.
6387 0, 0, 0, 0, // Replaced with size of .plt.
6388 0, // Augmentation size.
6389 elfcpp::DW_CFA_def_cfa_offset
, 16, // DW_CFA_def_cfa_offset: 16.
6390 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
6391 elfcpp::DW_CFA_def_cfa_offset
, 24, // DW_CFA_def_cfa_offset: 24.
6392 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
6393 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
6394 13, // Block length.
6395 elfcpp::DW_OP_breg7
, 8, // Push %rsp + 8.
6396 elfcpp::DW_OP_breg16
, 0, // Push %rip.
6397 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
6398 elfcpp::DW_OP_and
, // & (%rip & 0x3f).
6399 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
6400 elfcpp::DW_OP_ge
, // >= ((%rip & 0x3f) >= 0x25)
6401 elfcpp::DW_OP_lit3
, // Push 3.
6402 elfcpp::DW_OP_shl
, // << (((%rip & 0x3f) >= 0x25) << 3)
6403 elfcpp::DW_OP_plus
, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
6404 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
6408 // Return a string used to fill a code section with nops.
6409 // For NaCl, long NOPs are only valid if they do not cross
6410 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
6413 Target_x86_64_nacl
<size
>::do_code_fill(section_size_type length
) const
6415 return std::string(length
, static_cast<char>(0x90));
6418 // The selector for x86_64-nacl object files.
6421 class Target_selector_x86_64_nacl
6422 : public Target_selector_nacl
<Target_selector_x86_64
<size
>,
6423 Target_x86_64_nacl
<size
> >
6426 Target_selector_x86_64_nacl()
6427 : Target_selector_nacl
<Target_selector_x86_64
<size
>,
6428 Target_x86_64_nacl
<size
> >("x86-64",
6430 ? "elf64-x86-64-nacl"
6431 : "elf32-x86-64-nacl",
6434 : "elf32_x86_64_nacl")
6438 Target_selector_x86_64_nacl
<64> target_selector_x86_64
;
6439 Target_selector_x86_64_nacl
<32> target_selector_x32
;
6441 } // End anonymous namespace.