With -pie and x86, the linker complains if it sees a PC-relative relocation
[deliverable/binutils-gdb.git] / gold / x86_64.cc
1 // x86_64.cc -- x86_64 target support for gold.
2
3 // Copyright (C) 2006-2014 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
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.
12
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.
17
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.
22
23 #include "gold.h"
24
25 #include <cstring>
26
27 #include "elfcpp.h"
28 #include "dwarf.h"
29 #include "parameters.h"
30 #include "reloc.h"
31 #include "x86_64.h"
32 #include "object.h"
33 #include "symtab.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "copy-relocs.h"
37 #include "target.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
40 #include "tls.h"
41 #include "freebsd.h"
42 #include "nacl.h"
43 #include "gc.h"
44 #include "icf.h"
45
46 namespace
47 {
48
49 using namespace gold;
50
51 // A class to handle the .got.plt section.
52
53 class Output_data_got_plt_x86_64 : public Output_section_data_build
54 {
55 public:
56 Output_data_got_plt_x86_64(Layout* layout)
57 : Output_section_data_build(8),
58 layout_(layout)
59 { }
60
61 Output_data_got_plt_x86_64(Layout* layout, off_t data_size)
62 : Output_section_data_build(data_size, 8),
63 layout_(layout)
64 { }
65
66 protected:
67 // Write out the PLT data.
68 void
69 do_write(Output_file*);
70
71 // Write to a map file.
72 void
73 do_print_to_mapfile(Mapfile* mapfile) const
74 { mapfile->print_output_data(this, "** GOT PLT"); }
75
76 private:
77 // A pointer to the Layout class, so that we can find the .dynamic
78 // section when we write out the GOT PLT section.
79 Layout* layout_;
80 };
81
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.
86
87 template<int size>
88 class Output_data_plt_x86_64 : public Output_section_data
89 {
90 public:
91 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
92
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); }
102
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_()
113 {
114 this->init(layout);
115
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);
119 }
120
121 // Initialize the PLT section.
122 void
123 init(Layout* layout);
124
125 // Add an entry to the PLT.
126 void
127 add_entry(Symbol_table*, Layout*, Symbol* gsym);
128
129 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
130 unsigned int
131 add_local_ifunc_entry(Symbol_table* symtab, Layout*,
132 Sized_relobj_file<size, false>* relobj,
133 unsigned int local_sym_index);
134
135 // Add the relocation for a PLT entry.
136 void
137 add_relocation(Symbol_table*, Layout*, Symbol* gsym,
138 unsigned int got_offset);
139
140 // Add the reserved TLSDESC_PLT entry to the PLT.
141 void
142 reserve_tlsdesc_entry(unsigned int got_offset)
143 { this->tlsdesc_got_offset_ = got_offset; }
144
145 // Return true if a TLSDESC_PLT entry has been reserved.
146 bool
147 has_tlsdesc_entry() const
148 { return this->tlsdesc_got_offset_ != -1U; }
149
150 // Return the GOT offset for the reserved TLSDESC_PLT entry.
151 unsigned int
152 get_tlsdesc_got_offset() const
153 { return this->tlsdesc_got_offset_; }
154
155 // Return the offset of the reserved TLSDESC_PLT entry.
156 unsigned int
157 get_tlsdesc_plt_offset() const
158 {
159 return ((this->count_ + this->irelative_count_ + 1)
160 * this->get_plt_entry_size());
161 }
162
163 // Return the .rela.plt section data.
164 Reloc_section*
165 rela_plt()
166 { return this->rel_; }
167
168 // Return where the TLSDESC relocations should go.
169 Reloc_section*
170 rela_tlsdesc(Layout*);
171
172 // Return where the IRELATIVE relocations should go in the PLT
173 // relocations.
174 Reloc_section*
175 rela_irelative(Symbol_table*, Layout*);
176
177 // Return whether we created a section for IRELATIVE relocations.
178 bool
179 has_irelative_section() const
180 { return this->irelative_rel_ != NULL; }
181
182 // Return the number of PLT entries.
183 unsigned int
184 entry_count() const
185 { return this->count_ + this->irelative_count_; }
186
187 // Return the offset of the first non-reserved PLT entry.
188 unsigned int
189 first_plt_entry_offset()
190 { return this->get_plt_entry_size(); }
191
192 // Return the size of a PLT entry.
193 unsigned int
194 get_plt_entry_size() const
195 { return this->do_get_plt_entry_size(); }
196
197 // Reserve a slot in the PLT for an existing symbol in an incremental update.
198 void
199 reserve_slot(unsigned int plt_index)
200 {
201 this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(),
202 (plt_index + 2) * this->get_plt_entry_size());
203 }
204
205 // Return the PLT address to use for a global symbol.
206 uint64_t
207 address_for_global(const Symbol*);
208
209 // Return the PLT address to use for a local symbol.
210 uint64_t
211 address_for_local(const Relobj*, unsigned int symndx);
212
213 // Add .eh_frame information for the PLT.
214 void
215 add_eh_frame(Layout* layout)
216 { this->do_add_eh_frame(layout); }
217
218 protected:
219 // Fill in the first PLT entry.
220 void
221 fill_first_plt_entry(unsigned char* pov,
222 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
223 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
224 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
225
226 // Fill in a normal PLT entry. Returns the offset into the entry that
227 // should be the initial GOT slot value.
228 unsigned int
229 fill_plt_entry(unsigned char* pov,
230 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
231 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
232 unsigned int got_offset,
233 unsigned int plt_offset,
234 unsigned int plt_index)
235 {
236 return this->do_fill_plt_entry(pov, got_address, plt_address,
237 got_offset, plt_offset, plt_index);
238 }
239
240 // Fill in the reserved TLSDESC PLT entry.
241 void
242 fill_tlsdesc_entry(unsigned char* pov,
243 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
244 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
245 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
246 unsigned int tlsdesc_got_offset,
247 unsigned int plt_offset)
248 {
249 this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
250 tlsdesc_got_offset, plt_offset);
251 }
252
253 virtual unsigned int
254 do_get_plt_entry_size() const = 0;
255
256 virtual void
257 do_fill_first_plt_entry(unsigned char* pov,
258 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
259 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr)
260 = 0;
261
262 virtual unsigned int
263 do_fill_plt_entry(unsigned char* pov,
264 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
265 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
266 unsigned int got_offset,
267 unsigned int plt_offset,
268 unsigned int plt_index) = 0;
269
270 virtual void
271 do_fill_tlsdesc_entry(unsigned char* pov,
272 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
273 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
274 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
275 unsigned int tlsdesc_got_offset,
276 unsigned int plt_offset) = 0;
277
278 virtual void
279 do_add_eh_frame(Layout* layout) = 0;
280
281 void
282 do_adjust_output_section(Output_section* os);
283
284 // Write to a map file.
285 void
286 do_print_to_mapfile(Mapfile* mapfile) const
287 { mapfile->print_output_data(this, _("** PLT")); }
288
289 // The CIE of the .eh_frame unwind information for the PLT.
290 static const int plt_eh_frame_cie_size = 16;
291 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
292
293 private:
294 // Set the final size.
295 void
296 set_final_data_size();
297
298 // Write out the PLT data.
299 void
300 do_write(Output_file*);
301
302 // The reloc section.
303 Reloc_section* rel_;
304 // The TLSDESC relocs, if necessary. These must follow the regular
305 // PLT relocs.
306 Reloc_section* tlsdesc_rel_;
307 // The IRELATIVE relocs, if necessary. These must follow the
308 // regular PLT relocations and the TLSDESC relocations.
309 Reloc_section* irelative_rel_;
310 // The .got section.
311 Output_data_got<64, false>* got_;
312 // The .got.plt section.
313 Output_data_got_plt_x86_64* got_plt_;
314 // The part of the .got.plt section used for IRELATIVE relocs.
315 Output_data_space* got_irelative_;
316 // The number of PLT entries.
317 unsigned int count_;
318 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
319 // follow the regular PLT entries.
320 unsigned int irelative_count_;
321 // Offset of the reserved TLSDESC_GOT entry when needed.
322 unsigned int tlsdesc_got_offset_;
323 // List of available regions within the section, for incremental
324 // update links.
325 Free_list free_list_;
326 };
327
328 template<int size>
329 class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64<size>
330 {
331 public:
332 Output_data_plt_x86_64_standard(Layout* layout,
333 Output_data_got<64, false>* got,
334 Output_data_got_plt_x86_64* got_plt,
335 Output_data_space* got_irelative)
336 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
337 got, got_plt, got_irelative)
338 { }
339
340 Output_data_plt_x86_64_standard(Layout* layout,
341 Output_data_got<64, false>* got,
342 Output_data_got_plt_x86_64* got_plt,
343 Output_data_space* got_irelative,
344 unsigned int plt_count)
345 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
346 got, got_plt, got_irelative,
347 plt_count)
348 { }
349
350 protected:
351 virtual unsigned int
352 do_get_plt_entry_size() const
353 { return plt_entry_size; }
354
355 virtual void
356 do_add_eh_frame(Layout* layout)
357 {
358 layout->add_eh_frame_for_plt(this,
359 this->plt_eh_frame_cie,
360 this->plt_eh_frame_cie_size,
361 plt_eh_frame_fde,
362 plt_eh_frame_fde_size);
363 }
364
365 virtual void
366 do_fill_first_plt_entry(unsigned char* pov,
367 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
368 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
369
370 virtual unsigned int
371 do_fill_plt_entry(unsigned char* pov,
372 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
373 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
374 unsigned int got_offset,
375 unsigned int plt_offset,
376 unsigned int plt_index);
377
378 virtual void
379 do_fill_tlsdesc_entry(unsigned char* pov,
380 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
381 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
382 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
383 unsigned int tlsdesc_got_offset,
384 unsigned int plt_offset);
385
386 private:
387 // The size of an entry in the PLT.
388 static const int plt_entry_size = 16;
389
390 // The first entry in the PLT.
391 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
392 // procedure linkage table for both programs and shared objects."
393 static const unsigned char first_plt_entry[plt_entry_size];
394
395 // Other entries in the PLT for an executable.
396 static const unsigned char plt_entry[plt_entry_size];
397
398 // The reserved TLSDESC entry in the PLT for an executable.
399 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
400
401 // The .eh_frame unwind information for the PLT.
402 static const int plt_eh_frame_fde_size = 32;
403 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
404 };
405
406 // The x86_64 target class.
407 // See the ABI at
408 // http://www.x86-64.org/documentation/abi.pdf
409 // TLS info comes from
410 // http://people.redhat.com/drepper/tls.pdf
411 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
412
413 template<int size>
414 class Target_x86_64 : public Sized_target<size, false>
415 {
416 public:
417 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
418 // uses only Elf64_Rela relocation entries with explicit addends."
419 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
420
421 Target_x86_64(const Target::Target_info* info = &x86_64_info)
422 : Sized_target<size, false>(info),
423 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
424 got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
425 rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
426 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
427 tls_base_symbol_defined_(false)
428 { }
429
430 // Hook for a new output section.
431 void
432 do_new_output_section(Output_section*) const;
433
434 // Scan the relocations to look for symbol adjustments.
435 void
436 gc_process_relocs(Symbol_table* symtab,
437 Layout* layout,
438 Sized_relobj_file<size, false>* object,
439 unsigned int data_shndx,
440 unsigned int sh_type,
441 const unsigned char* prelocs,
442 size_t reloc_count,
443 Output_section* output_section,
444 bool needs_special_offset_handling,
445 size_t local_symbol_count,
446 const unsigned char* plocal_symbols);
447
448 // Scan the relocations to look for symbol adjustments.
449 void
450 scan_relocs(Symbol_table* symtab,
451 Layout* layout,
452 Sized_relobj_file<size, false>* object,
453 unsigned int data_shndx,
454 unsigned int sh_type,
455 const unsigned char* prelocs,
456 size_t reloc_count,
457 Output_section* output_section,
458 bool needs_special_offset_handling,
459 size_t local_symbol_count,
460 const unsigned char* plocal_symbols);
461
462 // Finalize the sections.
463 void
464 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
465
466 // Return the value to use for a dynamic which requires special
467 // treatment.
468 uint64_t
469 do_dynsym_value(const Symbol*) const;
470
471 // Relocate a section.
472 void
473 relocate_section(const Relocate_info<size, false>*,
474 unsigned int sh_type,
475 const unsigned char* prelocs,
476 size_t reloc_count,
477 Output_section* output_section,
478 bool needs_special_offset_handling,
479 unsigned char* view,
480 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
481 section_size_type view_size,
482 const Reloc_symbol_changes*);
483
484 // Scan the relocs during a relocatable link.
485 void
486 scan_relocatable_relocs(Symbol_table* symtab,
487 Layout* layout,
488 Sized_relobj_file<size, false>* object,
489 unsigned int data_shndx,
490 unsigned int sh_type,
491 const unsigned char* prelocs,
492 size_t reloc_count,
493 Output_section* output_section,
494 bool needs_special_offset_handling,
495 size_t local_symbol_count,
496 const unsigned char* plocal_symbols,
497 Relocatable_relocs*);
498
499 // Emit relocations for a section.
500 void
501 relocate_relocs(
502 const Relocate_info<size, false>*,
503 unsigned int sh_type,
504 const unsigned char* prelocs,
505 size_t reloc_count,
506 Output_section* output_section,
507 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
508 const Relocatable_relocs*,
509 unsigned char* view,
510 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
511 section_size_type view_size,
512 unsigned char* reloc_view,
513 section_size_type reloc_view_size);
514
515 // Return a string used to fill a code section with nops.
516 std::string
517 do_code_fill(section_size_type length) const;
518
519 // Return whether SYM is defined by the ABI.
520 bool
521 do_is_defined_by_abi(const Symbol* sym) const
522 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
523
524 // Return the symbol index to use for a target specific relocation.
525 // The only target specific relocation is R_X86_64_TLSDESC for a
526 // local symbol, which is an absolute reloc.
527 unsigned int
528 do_reloc_symbol_index(void*, unsigned int r_type) const
529 {
530 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
531 return 0;
532 }
533
534 // Return the addend to use for a target specific relocation.
535 uint64_t
536 do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
537
538 // Return the PLT section.
539 uint64_t
540 do_plt_address_for_global(const Symbol* gsym) const
541 { return this->plt_section()->address_for_global(gsym); }
542
543 uint64_t
544 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
545 { return this->plt_section()->address_for_local(relobj, symndx); }
546
547 // This function should be defined in targets that can use relocation
548 // types to determine (implemented in local_reloc_may_be_function_pointer
549 // and global_reloc_may_be_function_pointer)
550 // if a function's pointer is taken. ICF uses this in safe mode to only
551 // fold those functions whose pointer is defintely not taken. For x86_64
552 // pie binaries, safe ICF cannot be done by looking at relocation types.
553 bool
554 do_can_check_for_function_pointers() const
555 { return !parameters->options().pie(); }
556
557 // Return the base for a DW_EH_PE_datarel encoding.
558 uint64_t
559 do_ehframe_datarel_base() const;
560
561 // Adjust -fsplit-stack code which calls non-split-stack code.
562 void
563 do_calls_non_split(Relobj* object, unsigned int shndx,
564 section_offset_type fnoffset, section_size_type fnsize,
565 unsigned char* view, section_size_type view_size,
566 std::string* from, std::string* to) const;
567
568 // Return the size of the GOT section.
569 section_size_type
570 got_size() const
571 {
572 gold_assert(this->got_ != NULL);
573 return this->got_->data_size();
574 }
575
576 // Return the number of entries in the GOT.
577 unsigned int
578 got_entry_count() const
579 {
580 if (this->got_ == NULL)
581 return 0;
582 return this->got_size() / 8;
583 }
584
585 // Return the number of entries in the PLT.
586 unsigned int
587 plt_entry_count() const;
588
589 // Return the offset of the first non-reserved PLT entry.
590 unsigned int
591 first_plt_entry_offset() const;
592
593 // Return the size of each PLT entry.
594 unsigned int
595 plt_entry_size() const;
596
597 // Create the GOT section for an incremental update.
598 Output_data_got_base*
599 init_got_plt_for_update(Symbol_table* symtab,
600 Layout* layout,
601 unsigned int got_count,
602 unsigned int plt_count);
603
604 // Reserve a GOT entry for a local symbol, and regenerate any
605 // necessary dynamic relocations.
606 void
607 reserve_local_got_entry(unsigned int got_index,
608 Sized_relobj<size, false>* obj,
609 unsigned int r_sym,
610 unsigned int got_type);
611
612 // Reserve a GOT entry for a global symbol, and regenerate any
613 // necessary dynamic relocations.
614 void
615 reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
616 unsigned int got_type);
617
618 // Register an existing PLT entry for a global symbol.
619 void
620 register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
621 Symbol* gsym);
622
623 // Force a COPY relocation for a given symbol.
624 void
625 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
626
627 // Apply an incremental relocation.
628 void
629 apply_relocation(const Relocate_info<size, false>* relinfo,
630 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
631 unsigned int r_type,
632 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
633 const Symbol* gsym,
634 unsigned char* view,
635 typename elfcpp::Elf_types<size>::Elf_Addr address,
636 section_size_type view_size);
637
638 // Add a new reloc argument, returning the index in the vector.
639 size_t
640 add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
641 {
642 this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
643 return this->tlsdesc_reloc_info_.size() - 1;
644 }
645
646 Output_data_plt_x86_64<size>*
647 make_data_plt(Layout* layout,
648 Output_data_got<64, false>* got,
649 Output_data_got_plt_x86_64* got_plt,
650 Output_data_space* got_irelative)
651 {
652 return this->do_make_data_plt(layout, got, got_plt, got_irelative);
653 }
654
655 Output_data_plt_x86_64<size>*
656 make_data_plt(Layout* layout,
657 Output_data_got<64, false>* got,
658 Output_data_got_plt_x86_64* got_plt,
659 Output_data_space* got_irelative,
660 unsigned int plt_count)
661 {
662 return this->do_make_data_plt(layout, got, got_plt, got_irelative,
663 plt_count);
664 }
665
666 virtual Output_data_plt_x86_64<size>*
667 do_make_data_plt(Layout* layout,
668 Output_data_got<64, false>* got,
669 Output_data_got_plt_x86_64* got_plt,
670 Output_data_space* got_irelative)
671 {
672 return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
673 got_irelative);
674 }
675
676 virtual Output_data_plt_x86_64<size>*
677 do_make_data_plt(Layout* layout,
678 Output_data_got<64, false>* got,
679 Output_data_got_plt_x86_64* got_plt,
680 Output_data_space* got_irelative,
681 unsigned int plt_count)
682 {
683 return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
684 got_irelative,
685 plt_count);
686 }
687
688 private:
689 // The class which scans relocations.
690 class Scan
691 {
692 public:
693 Scan()
694 : issued_non_pic_error_(false)
695 { }
696
697 static inline int
698 get_reference_flags(unsigned int r_type);
699
700 inline void
701 local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
702 Sized_relobj_file<size, false>* object,
703 unsigned int data_shndx,
704 Output_section* output_section,
705 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
706 const elfcpp::Sym<size, false>& lsym,
707 bool is_discarded);
708
709 inline void
710 global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
711 Sized_relobj_file<size, false>* object,
712 unsigned int data_shndx,
713 Output_section* output_section,
714 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
715 Symbol* gsym);
716
717 inline bool
718 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
719 Target_x86_64* target,
720 Sized_relobj_file<size, false>* object,
721 unsigned int data_shndx,
722 Output_section* output_section,
723 const elfcpp::Rela<size, false>& reloc,
724 unsigned int r_type,
725 const elfcpp::Sym<size, false>& lsym);
726
727 inline bool
728 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
729 Target_x86_64* target,
730 Sized_relobj_file<size, false>* object,
731 unsigned int data_shndx,
732 Output_section* output_section,
733 const elfcpp::Rela<size, false>& reloc,
734 unsigned int r_type,
735 Symbol* gsym);
736
737 private:
738 static void
739 unsupported_reloc_local(Sized_relobj_file<size, false>*,
740 unsigned int r_type);
741
742 static void
743 unsupported_reloc_global(Sized_relobj_file<size, false>*,
744 unsigned int r_type, Symbol*);
745
746 void
747 check_non_pic(Relobj*, unsigned int r_type, Symbol*);
748
749 inline bool
750 possible_function_pointer_reloc(unsigned int r_type);
751
752 bool
753 reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
754 unsigned int r_type);
755
756 // Whether we have issued an error about a non-PIC compilation.
757 bool issued_non_pic_error_;
758 };
759
760 // The class which implements relocation.
761 class Relocate
762 {
763 public:
764 Relocate()
765 : skip_call_tls_get_addr_(false)
766 { }
767
768 ~Relocate()
769 {
770 if (this->skip_call_tls_get_addr_)
771 {
772 // FIXME: This needs to specify the location somehow.
773 gold_error(_("missing expected TLS relocation"));
774 }
775 }
776
777 // Do a relocation. Return false if the caller should not issue
778 // any warnings about this relocation.
779 inline bool
780 relocate(const Relocate_info<size, false>*, Target_x86_64*,
781 Output_section*,
782 size_t relnum, const elfcpp::Rela<size, false>&,
783 unsigned int r_type, const Sized_symbol<size>*,
784 const Symbol_value<size>*,
785 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
786 section_size_type);
787
788 private:
789 // Do a TLS relocation.
790 inline void
791 relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
792 size_t relnum, const elfcpp::Rela<size, false>&,
793 unsigned int r_type, const Sized_symbol<size>*,
794 const Symbol_value<size>*,
795 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
796 section_size_type);
797
798 // Do a TLS General-Dynamic to Initial-Exec transition.
799 inline void
800 tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
801 Output_segment* tls_segment,
802 const elfcpp::Rela<size, false>&, unsigned int r_type,
803 typename elfcpp::Elf_types<size>::Elf_Addr value,
804 unsigned char* view,
805 typename elfcpp::Elf_types<size>::Elf_Addr,
806 section_size_type view_size);
807
808 // Do a TLS General-Dynamic to Local-Exec transition.
809 inline void
810 tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
811 Output_segment* tls_segment,
812 const elfcpp::Rela<size, false>&, unsigned int r_type,
813 typename elfcpp::Elf_types<size>::Elf_Addr value,
814 unsigned char* view,
815 section_size_type view_size);
816
817 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
818 inline void
819 tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
820 Output_segment* tls_segment,
821 const elfcpp::Rela<size, false>&, unsigned int r_type,
822 typename elfcpp::Elf_types<size>::Elf_Addr value,
823 unsigned char* view,
824 typename elfcpp::Elf_types<size>::Elf_Addr,
825 section_size_type view_size);
826
827 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
828 inline void
829 tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
830 Output_segment* tls_segment,
831 const elfcpp::Rela<size, false>&, unsigned int r_type,
832 typename elfcpp::Elf_types<size>::Elf_Addr value,
833 unsigned char* view,
834 section_size_type view_size);
835
836 // Do a TLS Local-Dynamic to Local-Exec transition.
837 inline void
838 tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
839 Output_segment* tls_segment,
840 const elfcpp::Rela<size, false>&, unsigned int r_type,
841 typename elfcpp::Elf_types<size>::Elf_Addr value,
842 unsigned char* view,
843 section_size_type view_size);
844
845 // Do a TLS Initial-Exec to Local-Exec transition.
846 static inline void
847 tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
848 Output_segment* tls_segment,
849 const elfcpp::Rela<size, false>&, unsigned int r_type,
850 typename elfcpp::Elf_types<size>::Elf_Addr value,
851 unsigned char* view,
852 section_size_type view_size);
853
854 // This is set if we should skip the next reloc, which should be a
855 // PLT32 reloc against ___tls_get_addr.
856 bool skip_call_tls_get_addr_;
857 };
858
859 // A class which returns the size required for a relocation type,
860 // used while scanning relocs during a relocatable link.
861 class Relocatable_size_for_reloc
862 {
863 public:
864 unsigned int
865 get_size_for_reloc(unsigned int, Relobj*);
866 };
867
868 // Adjust TLS relocation type based on the options and whether this
869 // is a local symbol.
870 static tls::Tls_optimization
871 optimize_tls_reloc(bool is_final, int r_type);
872
873 // Get the GOT section, creating it if necessary.
874 Output_data_got<64, false>*
875 got_section(Symbol_table*, Layout*);
876
877 // Get the GOT PLT section.
878 Output_data_got_plt_x86_64*
879 got_plt_section() const
880 {
881 gold_assert(this->got_plt_ != NULL);
882 return this->got_plt_;
883 }
884
885 // Get the GOT section for TLSDESC entries.
886 Output_data_got<64, false>*
887 got_tlsdesc_section() const
888 {
889 gold_assert(this->got_tlsdesc_ != NULL);
890 return this->got_tlsdesc_;
891 }
892
893 // Create the PLT section.
894 void
895 make_plt_section(Symbol_table* symtab, Layout* layout);
896
897 // Create a PLT entry for a global symbol.
898 void
899 make_plt_entry(Symbol_table*, Layout*, Symbol*);
900
901 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
902 void
903 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
904 Sized_relobj_file<size, false>* relobj,
905 unsigned int local_sym_index);
906
907 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
908 void
909 define_tls_base_symbol(Symbol_table*, Layout*);
910
911 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
912 void
913 reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
914
915 // Create a GOT entry for the TLS module index.
916 unsigned int
917 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
918 Sized_relobj_file<size, false>* object);
919
920 // Get the PLT section.
921 Output_data_plt_x86_64<size>*
922 plt_section() const
923 {
924 gold_assert(this->plt_ != NULL);
925 return this->plt_;
926 }
927
928 // Get the dynamic reloc section, creating it if necessary.
929 Reloc_section*
930 rela_dyn_section(Layout*);
931
932 // Get the section to use for TLSDESC relocations.
933 Reloc_section*
934 rela_tlsdesc_section(Layout*) const;
935
936 // Get the section to use for IRELATIVE relocations.
937 Reloc_section*
938 rela_irelative_section(Layout*);
939
940 // Add a potential copy relocation.
941 void
942 copy_reloc(Symbol_table* symtab, Layout* layout,
943 Sized_relobj_file<size, false>* object,
944 unsigned int shndx, Output_section* output_section,
945 Symbol* sym, const elfcpp::Rela<size, false>& reloc)
946 {
947 this->copy_relocs_.copy_reloc(symtab, layout,
948 symtab->get_sized_symbol<size>(sym),
949 object, shndx, output_section,
950 reloc, this->rela_dyn_section(layout));
951 }
952
953 // Information about this specific target which we pass to the
954 // general Target structure.
955 static const Target::Target_info x86_64_info;
956
957 // The types of GOT entries needed for this platform.
958 // These values are exposed to the ABI in an incremental link.
959 // Do not renumber existing values without changing the version
960 // number of the .gnu_incremental_inputs section.
961 enum Got_type
962 {
963 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
964 GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
965 GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
966 GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
967 };
968
969 // This type is used as the argument to the target specific
970 // relocation routines. The only target specific reloc is
971 // R_X86_64_TLSDESC against a local symbol.
972 struct Tlsdesc_info
973 {
974 Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
975 : object(a_object), r_sym(a_r_sym)
976 { }
977
978 // The object in which the local symbol is defined.
979 Sized_relobj_file<size, false>* object;
980 // The local symbol index in the object.
981 unsigned int r_sym;
982 };
983
984 // The GOT section.
985 Output_data_got<64, false>* got_;
986 // The PLT section.
987 Output_data_plt_x86_64<size>* plt_;
988 // The GOT PLT section.
989 Output_data_got_plt_x86_64* got_plt_;
990 // The GOT section for IRELATIVE relocations.
991 Output_data_space* got_irelative_;
992 // The GOT section for TLSDESC relocations.
993 Output_data_got<64, false>* got_tlsdesc_;
994 // The _GLOBAL_OFFSET_TABLE_ symbol.
995 Symbol* global_offset_table_;
996 // The dynamic reloc section.
997 Reloc_section* rela_dyn_;
998 // The section to use for IRELATIVE relocs.
999 Reloc_section* rela_irelative_;
1000 // Relocs saved to avoid a COPY reloc.
1001 Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1002 // Offset of the GOT entry for the TLS module index.
1003 unsigned int got_mod_index_offset_;
1004 // We handle R_X86_64_TLSDESC against a local symbol as a target
1005 // specific relocation. Here we store the object and local symbol
1006 // index for the relocation.
1007 std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1008 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1009 bool tls_base_symbol_defined_;
1010 };
1011
1012 template<>
1013 const Target::Target_info Target_x86_64<64>::x86_64_info =
1014 {
1015 64, // size
1016 false, // is_big_endian
1017 elfcpp::EM_X86_64, // machine_code
1018 false, // has_make_symbol
1019 false, // has_resolve
1020 true, // has_code_fill
1021 true, // is_default_stack_executable
1022 true, // can_icf_inline_merge_sections
1023 '\0', // wrap_char
1024 "/lib/ld64.so.1", // program interpreter
1025 0x400000, // default_text_segment_address
1026 0x1000, // abi_pagesize (overridable by -z max-page-size)
1027 0x1000, // common_pagesize (overridable by -z common-page-size)
1028 false, // isolate_execinstr
1029 0, // rosegment_gap
1030 elfcpp::SHN_UNDEF, // small_common_shndx
1031 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1032 0, // small_common_section_flags
1033 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1034 NULL, // attributes_section
1035 NULL, // attributes_vendor
1036 "_start" // entry_symbol_name
1037 };
1038
1039 template<>
1040 const Target::Target_info Target_x86_64<32>::x86_64_info =
1041 {
1042 32, // size
1043 false, // is_big_endian
1044 elfcpp::EM_X86_64, // machine_code
1045 false, // has_make_symbol
1046 false, // has_resolve
1047 true, // has_code_fill
1048 true, // is_default_stack_executable
1049 true, // can_icf_inline_merge_sections
1050 '\0', // wrap_char
1051 "/libx32/ldx32.so.1", // program interpreter
1052 0x400000, // default_text_segment_address
1053 0x1000, // abi_pagesize (overridable by -z max-page-size)
1054 0x1000, // common_pagesize (overridable by -z common-page-size)
1055 false, // isolate_execinstr
1056 0, // rosegment_gap
1057 elfcpp::SHN_UNDEF, // small_common_shndx
1058 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1059 0, // small_common_section_flags
1060 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1061 NULL, // attributes_section
1062 NULL, // attributes_vendor
1063 "_start" // entry_symbol_name
1064 };
1065
1066 // This is called when a new output section is created. This is where
1067 // we handle the SHF_X86_64_LARGE.
1068
1069 template<int size>
1070 void
1071 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1072 {
1073 if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1074 os->set_is_large_section();
1075 }
1076
1077 // Get the GOT section, creating it if necessary.
1078
1079 template<int size>
1080 Output_data_got<64, false>*
1081 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1082 {
1083 if (this->got_ == NULL)
1084 {
1085 gold_assert(symtab != NULL && layout != NULL);
1086
1087 // When using -z now, we can treat .got.plt as a relro section.
1088 // Without -z now, it is modified after program startup by lazy
1089 // PLT relocations.
1090 bool is_got_plt_relro = parameters->options().now();
1091 Output_section_order got_order = (is_got_plt_relro
1092 ? ORDER_RELRO
1093 : ORDER_RELRO_LAST);
1094 Output_section_order got_plt_order = (is_got_plt_relro
1095 ? ORDER_RELRO
1096 : ORDER_NON_RELRO_FIRST);
1097
1098 this->got_ = new Output_data_got<64, false>();
1099
1100 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1101 (elfcpp::SHF_ALLOC
1102 | elfcpp::SHF_WRITE),
1103 this->got_, got_order, true);
1104
1105 this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1106 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1107 (elfcpp::SHF_ALLOC
1108 | elfcpp::SHF_WRITE),
1109 this->got_plt_, got_plt_order,
1110 is_got_plt_relro);
1111
1112 // The first three entries are reserved.
1113 this->got_plt_->set_current_data_size(3 * 8);
1114
1115 if (!is_got_plt_relro)
1116 {
1117 // Those bytes can go into the relro segment.
1118 layout->increase_relro(3 * 8);
1119 }
1120
1121 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1122 this->global_offset_table_ =
1123 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1124 Symbol_table::PREDEFINED,
1125 this->got_plt_,
1126 0, 0, elfcpp::STT_OBJECT,
1127 elfcpp::STB_LOCAL,
1128 elfcpp::STV_HIDDEN, 0,
1129 false, false);
1130
1131 // If there are any IRELATIVE relocations, they get GOT entries
1132 // in .got.plt after the jump slot entries.
1133 this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1134 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1135 (elfcpp::SHF_ALLOC
1136 | elfcpp::SHF_WRITE),
1137 this->got_irelative_,
1138 got_plt_order, is_got_plt_relro);
1139
1140 // If there are any TLSDESC relocations, they get GOT entries in
1141 // .got.plt after the jump slot and IRELATIVE entries.
1142 this->got_tlsdesc_ = new Output_data_got<64, false>();
1143 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1144 (elfcpp::SHF_ALLOC
1145 | elfcpp::SHF_WRITE),
1146 this->got_tlsdesc_,
1147 got_plt_order, is_got_plt_relro);
1148 }
1149
1150 return this->got_;
1151 }
1152
1153 // Get the dynamic reloc section, creating it if necessary.
1154
1155 template<int size>
1156 typename Target_x86_64<size>::Reloc_section*
1157 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1158 {
1159 if (this->rela_dyn_ == NULL)
1160 {
1161 gold_assert(layout != NULL);
1162 this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1163 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1164 elfcpp::SHF_ALLOC, this->rela_dyn_,
1165 ORDER_DYNAMIC_RELOCS, false);
1166 }
1167 return this->rela_dyn_;
1168 }
1169
1170 // Get the section to use for IRELATIVE relocs, creating it if
1171 // necessary. These go in .rela.dyn, but only after all other dynamic
1172 // relocations. They need to follow the other dynamic relocations so
1173 // that they can refer to global variables initialized by those
1174 // relocs.
1175
1176 template<int size>
1177 typename Target_x86_64<size>::Reloc_section*
1178 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1179 {
1180 if (this->rela_irelative_ == NULL)
1181 {
1182 // Make sure we have already created the dynamic reloc section.
1183 this->rela_dyn_section(layout);
1184 this->rela_irelative_ = new Reloc_section(false);
1185 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1186 elfcpp::SHF_ALLOC, this->rela_irelative_,
1187 ORDER_DYNAMIC_RELOCS, false);
1188 gold_assert(this->rela_dyn_->output_section()
1189 == this->rela_irelative_->output_section());
1190 }
1191 return this->rela_irelative_;
1192 }
1193
1194 // Write the first three reserved words of the .got.plt section.
1195 // The remainder of the section is written while writing the PLT
1196 // in Output_data_plt_i386::do_write.
1197
1198 void
1199 Output_data_got_plt_x86_64::do_write(Output_file* of)
1200 {
1201 // The first entry in the GOT is the address of the .dynamic section
1202 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1203 // We saved space for them when we created the section in
1204 // Target_x86_64::got_section.
1205 const off_t got_file_offset = this->offset();
1206 gold_assert(this->data_size() >= 24);
1207 unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1208 Output_section* dynamic = this->layout_->dynamic_section();
1209 uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1210 elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1211 memset(got_view + 8, 0, 16);
1212 of->write_output_view(got_file_offset, 24, got_view);
1213 }
1214
1215 // Initialize the PLT section.
1216
1217 template<int size>
1218 void
1219 Output_data_plt_x86_64<size>::init(Layout* layout)
1220 {
1221 this->rel_ = new Reloc_section(false);
1222 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1223 elfcpp::SHF_ALLOC, this->rel_,
1224 ORDER_DYNAMIC_PLT_RELOCS, false);
1225 }
1226
1227 template<int size>
1228 void
1229 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1230 {
1231 os->set_entsize(this->get_plt_entry_size());
1232 }
1233
1234 // Add an entry to the PLT.
1235
1236 template<int size>
1237 void
1238 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1239 Symbol* gsym)
1240 {
1241 gold_assert(!gsym->has_plt_offset());
1242
1243 unsigned int plt_index;
1244 off_t plt_offset;
1245 section_offset_type got_offset;
1246
1247 unsigned int* pcount;
1248 unsigned int offset;
1249 unsigned int reserved;
1250 Output_section_data_build* got;
1251 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1252 && gsym->can_use_relative_reloc(false))
1253 {
1254 pcount = &this->irelative_count_;
1255 offset = 0;
1256 reserved = 0;
1257 got = this->got_irelative_;
1258 }
1259 else
1260 {
1261 pcount = &this->count_;
1262 offset = 1;
1263 reserved = 3;
1264 got = this->got_plt_;
1265 }
1266
1267 if (!this->is_data_size_valid())
1268 {
1269 // Note that when setting the PLT offset for a non-IRELATIVE
1270 // entry we skip the initial reserved PLT entry.
1271 plt_index = *pcount + offset;
1272 plt_offset = plt_index * this->get_plt_entry_size();
1273
1274 ++*pcount;
1275
1276 got_offset = (plt_index - offset + reserved) * 8;
1277 gold_assert(got_offset == got->current_data_size());
1278
1279 // Every PLT entry needs a GOT entry which points back to the PLT
1280 // entry (this will be changed by the dynamic linker, normally
1281 // lazily when the function is called).
1282 got->set_current_data_size(got_offset + 8);
1283 }
1284 else
1285 {
1286 // FIXME: This is probably not correct for IRELATIVE relocs.
1287
1288 // For incremental updates, find an available slot.
1289 plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1290 this->get_plt_entry_size(), 0);
1291 if (plt_offset == -1)
1292 gold_fallback(_("out of patch space (PLT);"
1293 " relink with --incremental-full"));
1294
1295 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1296 // can be calculated from the PLT index, adjusting for the three
1297 // reserved entries at the beginning of the GOT.
1298 plt_index = plt_offset / this->get_plt_entry_size() - 1;
1299 got_offset = (plt_index - offset + reserved) * 8;
1300 }
1301
1302 gsym->set_plt_offset(plt_offset);
1303
1304 // Every PLT entry needs a reloc.
1305 this->add_relocation(symtab, layout, gsym, got_offset);
1306
1307 // Note that we don't need to save the symbol. The contents of the
1308 // PLT are independent of which symbols are used. The symbols only
1309 // appear in the relocations.
1310 }
1311
1312 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1313 // the PLT offset.
1314
1315 template<int size>
1316 unsigned int
1317 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1318 Symbol_table* symtab,
1319 Layout* layout,
1320 Sized_relobj_file<size, false>* relobj,
1321 unsigned int local_sym_index)
1322 {
1323 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1324 ++this->irelative_count_;
1325
1326 section_offset_type got_offset = this->got_irelative_->current_data_size();
1327
1328 // Every PLT entry needs a GOT entry which points back to the PLT
1329 // entry.
1330 this->got_irelative_->set_current_data_size(got_offset + 8);
1331
1332 // Every PLT entry needs a reloc.
1333 Reloc_section* rela = this->rela_irelative(symtab, layout);
1334 rela->add_symbolless_local_addend(relobj, local_sym_index,
1335 elfcpp::R_X86_64_IRELATIVE,
1336 this->got_irelative_, got_offset, 0);
1337
1338 return plt_offset;
1339 }
1340
1341 // Add the relocation for a PLT entry.
1342
1343 template<int size>
1344 void
1345 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1346 Layout* layout,
1347 Symbol* gsym,
1348 unsigned int got_offset)
1349 {
1350 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1351 && gsym->can_use_relative_reloc(false))
1352 {
1353 Reloc_section* rela = this->rela_irelative(symtab, layout);
1354 rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1355 this->got_irelative_, got_offset, 0);
1356 }
1357 else
1358 {
1359 gsym->set_needs_dynsym_entry();
1360 this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1361 got_offset, 0);
1362 }
1363 }
1364
1365 // Return where the TLSDESC relocations should go, creating it if
1366 // necessary. These follow the JUMP_SLOT relocations.
1367
1368 template<int size>
1369 typename Output_data_plt_x86_64<size>::Reloc_section*
1370 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1371 {
1372 if (this->tlsdesc_rel_ == NULL)
1373 {
1374 this->tlsdesc_rel_ = new Reloc_section(false);
1375 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1376 elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1377 ORDER_DYNAMIC_PLT_RELOCS, false);
1378 gold_assert(this->tlsdesc_rel_->output_section()
1379 == this->rel_->output_section());
1380 }
1381 return this->tlsdesc_rel_;
1382 }
1383
1384 // Return where the IRELATIVE relocations should go in the PLT. These
1385 // follow the JUMP_SLOT and the TLSDESC relocations.
1386
1387 template<int size>
1388 typename Output_data_plt_x86_64<size>::Reloc_section*
1389 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1390 Layout* layout)
1391 {
1392 if (this->irelative_rel_ == NULL)
1393 {
1394 // Make sure we have a place for the TLSDESC relocations, in
1395 // case we see any later on.
1396 this->rela_tlsdesc(layout);
1397 this->irelative_rel_ = new Reloc_section(false);
1398 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1399 elfcpp::SHF_ALLOC, this->irelative_rel_,
1400 ORDER_DYNAMIC_PLT_RELOCS, false);
1401 gold_assert(this->irelative_rel_->output_section()
1402 == this->rel_->output_section());
1403
1404 if (parameters->doing_static_link())
1405 {
1406 // A statically linked executable will only have a .rela.plt
1407 // section to hold R_X86_64_IRELATIVE relocs for
1408 // STT_GNU_IFUNC symbols. The library will use these
1409 // symbols to locate the IRELATIVE relocs at program startup
1410 // time.
1411 symtab->define_in_output_data("__rela_iplt_start", NULL,
1412 Symbol_table::PREDEFINED,
1413 this->irelative_rel_, 0, 0,
1414 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1415 elfcpp::STV_HIDDEN, 0, false, true);
1416 symtab->define_in_output_data("__rela_iplt_end", NULL,
1417 Symbol_table::PREDEFINED,
1418 this->irelative_rel_, 0, 0,
1419 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1420 elfcpp::STV_HIDDEN, 0, true, true);
1421 }
1422 }
1423 return this->irelative_rel_;
1424 }
1425
1426 // Return the PLT address to use for a global symbol.
1427
1428 template<int size>
1429 uint64_t
1430 Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
1431 {
1432 uint64_t offset = 0;
1433 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1434 && gsym->can_use_relative_reloc(false))
1435 offset = (this->count_ + 1) * this->get_plt_entry_size();
1436 return this->address() + offset + gsym->plt_offset();
1437 }
1438
1439 // Return the PLT address to use for a local symbol. These are always
1440 // IRELATIVE relocs.
1441
1442 template<int size>
1443 uint64_t
1444 Output_data_plt_x86_64<size>::address_for_local(const Relobj* object,
1445 unsigned int r_sym)
1446 {
1447 return (this->address()
1448 + (this->count_ + 1) * this->get_plt_entry_size()
1449 + object->local_plt_offset(r_sym));
1450 }
1451
1452 // Set the final size.
1453 template<int size>
1454 void
1455 Output_data_plt_x86_64<size>::set_final_data_size()
1456 {
1457 unsigned int count = this->count_ + this->irelative_count_;
1458 if (this->has_tlsdesc_entry())
1459 ++count;
1460 this->set_data_size((count + 1) * this->get_plt_entry_size());
1461 }
1462
1463 // The first entry in the PLT for an executable.
1464
1465 template<int size>
1466 const unsigned char
1467 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1468 {
1469 // From AMD64 ABI Draft 0.98, page 76
1470 0xff, 0x35, // pushq contents of memory address
1471 0, 0, 0, 0, // replaced with address of .got + 8
1472 0xff, 0x25, // jmp indirect
1473 0, 0, 0, 0, // replaced with address of .got + 16
1474 0x90, 0x90, 0x90, 0x90 // noop (x4)
1475 };
1476
1477 template<int size>
1478 void
1479 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1480 unsigned char* pov,
1481 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1482 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1483 {
1484 memcpy(pov, first_plt_entry, plt_entry_size);
1485 // We do a jmp relative to the PC at the end of this instruction.
1486 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1487 (got_address + 8
1488 - (plt_address + 6)));
1489 elfcpp::Swap<32, false>::writeval(pov + 8,
1490 (got_address + 16
1491 - (plt_address + 12)));
1492 }
1493
1494 // Subsequent entries in the PLT for an executable.
1495
1496 template<int size>
1497 const unsigned char
1498 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1499 {
1500 // From AMD64 ABI Draft 0.98, page 76
1501 0xff, 0x25, // jmpq indirect
1502 0, 0, 0, 0, // replaced with address of symbol in .got
1503 0x68, // pushq immediate
1504 0, 0, 0, 0, // replaced with offset into relocation table
1505 0xe9, // jmpq relative
1506 0, 0, 0, 0 // replaced with offset to start of .plt
1507 };
1508
1509 template<int size>
1510 unsigned int
1511 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1512 unsigned char* pov,
1513 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1514 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1515 unsigned int got_offset,
1516 unsigned int plt_offset,
1517 unsigned int plt_index)
1518 {
1519 memcpy(pov, plt_entry, plt_entry_size);
1520 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1521 (got_address + got_offset
1522 - (plt_address + plt_offset
1523 + 6)));
1524
1525 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1526 elfcpp::Swap<32, false>::writeval(pov + 12,
1527 - (plt_offset + plt_entry_size));
1528
1529 return 6;
1530 }
1531
1532 // The reserved TLSDESC entry in the PLT for an executable.
1533
1534 template<int size>
1535 const unsigned char
1536 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
1537 {
1538 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1539 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1540 0xff, 0x35, // pushq x(%rip)
1541 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1542 0xff, 0x25, // jmpq *y(%rip)
1543 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1544 0x0f, 0x1f, // nop
1545 0x40, 0
1546 };
1547
1548 template<int size>
1549 void
1550 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
1551 unsigned char* pov,
1552 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1553 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1554 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
1555 unsigned int tlsdesc_got_offset,
1556 unsigned int plt_offset)
1557 {
1558 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1559 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1560 (got_address + 8
1561 - (plt_address + plt_offset
1562 + 6)));
1563 elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1564 (got_base
1565 + tlsdesc_got_offset
1566 - (plt_address + plt_offset
1567 + 12)));
1568 }
1569
1570 // The .eh_frame unwind information for the PLT.
1571
1572 template<int size>
1573 const unsigned char
1574 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1575 {
1576 1, // CIE version.
1577 'z', // Augmentation: augmentation size included.
1578 'R', // Augmentation: FDE encoding included.
1579 '\0', // End of augmentation string.
1580 1, // Code alignment factor.
1581 0x78, // Data alignment factor.
1582 16, // Return address column.
1583 1, // Augmentation size.
1584 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1585 | elfcpp::DW_EH_PE_sdata4),
1586 elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1587 elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1588 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1589 elfcpp::DW_CFA_nop
1590 };
1591
1592 template<int size>
1593 const unsigned char
1594 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1595 {
1596 0, 0, 0, 0, // Replaced with offset to .plt.
1597 0, 0, 0, 0, // Replaced with size of .plt.
1598 0, // Augmentation size.
1599 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
1600 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1601 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
1602 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1603 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1604 11, // Block length.
1605 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
1606 elfcpp::DW_OP_breg16, 0, // Push %rip.
1607 elfcpp::DW_OP_lit15, // Push 0xf.
1608 elfcpp::DW_OP_and, // & (%rip & 0xf).
1609 elfcpp::DW_OP_lit11, // Push 0xb.
1610 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
1611 elfcpp::DW_OP_lit3, // Push 3.
1612 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
1613 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1614 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1615 elfcpp::DW_CFA_nop,
1616 elfcpp::DW_CFA_nop,
1617 elfcpp::DW_CFA_nop
1618 };
1619
1620 // Write out the PLT. This uses the hand-coded instructions above,
1621 // and adjusts them as needed. This is specified by the AMD64 ABI.
1622
1623 template<int size>
1624 void
1625 Output_data_plt_x86_64<size>::do_write(Output_file* of)
1626 {
1627 const off_t offset = this->offset();
1628 const section_size_type oview_size =
1629 convert_to_section_size_type(this->data_size());
1630 unsigned char* const oview = of->get_output_view(offset, oview_size);
1631
1632 const off_t got_file_offset = this->got_plt_->offset();
1633 gold_assert(parameters->incremental_update()
1634 || (got_file_offset + this->got_plt_->data_size()
1635 == this->got_irelative_->offset()));
1636 const section_size_type got_size =
1637 convert_to_section_size_type(this->got_plt_->data_size()
1638 + this->got_irelative_->data_size());
1639 unsigned char* const got_view = of->get_output_view(got_file_offset,
1640 got_size);
1641
1642 unsigned char* pov = oview;
1643
1644 // The base address of the .plt section.
1645 typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
1646 // The base address of the .got section.
1647 typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
1648 // The base address of the PLT portion of the .got section,
1649 // which is where the GOT pointer will point, and where the
1650 // three reserved GOT entries are located.
1651 typename elfcpp::Elf_types<size>::Elf_Addr got_address
1652 = this->got_plt_->address();
1653
1654 this->fill_first_plt_entry(pov, got_address, plt_address);
1655 pov += this->get_plt_entry_size();
1656
1657 // The first three entries in the GOT are reserved, and are written
1658 // by Output_data_got_plt_x86_64::do_write.
1659 unsigned char* got_pov = got_view + 24;
1660
1661 unsigned int plt_offset = this->get_plt_entry_size();
1662 unsigned int got_offset = 24;
1663 const unsigned int count = this->count_ + this->irelative_count_;
1664 for (unsigned int plt_index = 0;
1665 plt_index < count;
1666 ++plt_index,
1667 pov += this->get_plt_entry_size(),
1668 got_pov += 8,
1669 plt_offset += this->get_plt_entry_size(),
1670 got_offset += 8)
1671 {
1672 // Set and adjust the PLT entry itself.
1673 unsigned int lazy_offset = this->fill_plt_entry(pov,
1674 got_address, plt_address,
1675 got_offset, plt_offset,
1676 plt_index);
1677
1678 // Set the entry in the GOT.
1679 elfcpp::Swap<64, false>::writeval(got_pov,
1680 plt_address + plt_offset + lazy_offset);
1681 }
1682
1683 if (this->has_tlsdesc_entry())
1684 {
1685 // Set and adjust the reserved TLSDESC PLT entry.
1686 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1687 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
1688 tlsdesc_got_offset, plt_offset);
1689 pov += this->get_plt_entry_size();
1690 }
1691
1692 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1693 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1694
1695 of->write_output_view(offset, oview_size, oview);
1696 of->write_output_view(got_file_offset, got_size, got_view);
1697 }
1698
1699 // Create the PLT section.
1700
1701 template<int size>
1702 void
1703 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
1704 {
1705 if (this->plt_ == NULL)
1706 {
1707 // Create the GOT sections first.
1708 this->got_section(symtab, layout);
1709
1710 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
1711 this->got_irelative_);
1712
1713 // Add unwind information if requested.
1714 if (parameters->options().ld_generated_unwind_info())
1715 this->plt_->add_eh_frame(layout);
1716
1717 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1718 (elfcpp::SHF_ALLOC
1719 | elfcpp::SHF_EXECINSTR),
1720 this->plt_, ORDER_PLT, false);
1721
1722 // Make the sh_info field of .rela.plt point to .plt.
1723 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1724 rela_plt_os->set_info_section(this->plt_->output_section());
1725 }
1726 }
1727
1728 // Return the section for TLSDESC relocations.
1729
1730 template<int size>
1731 typename Target_x86_64<size>::Reloc_section*
1732 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
1733 {
1734 return this->plt_section()->rela_tlsdesc(layout);
1735 }
1736
1737 // Create a PLT entry for a global symbol.
1738
1739 template<int size>
1740 void
1741 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
1742 Symbol* gsym)
1743 {
1744 if (gsym->has_plt_offset())
1745 return;
1746
1747 if (this->plt_ == NULL)
1748 this->make_plt_section(symtab, layout);
1749
1750 this->plt_->add_entry(symtab, layout, gsym);
1751 }
1752
1753 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1754
1755 template<int size>
1756 void
1757 Target_x86_64<size>::make_local_ifunc_plt_entry(
1758 Symbol_table* symtab, Layout* layout,
1759 Sized_relobj_file<size, false>* relobj,
1760 unsigned int local_sym_index)
1761 {
1762 if (relobj->local_has_plt_offset(local_sym_index))
1763 return;
1764 if (this->plt_ == NULL)
1765 this->make_plt_section(symtab, layout);
1766 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1767 relobj,
1768 local_sym_index);
1769 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1770 }
1771
1772 // Return the number of entries in the PLT.
1773
1774 template<int size>
1775 unsigned int
1776 Target_x86_64<size>::plt_entry_count() const
1777 {
1778 if (this->plt_ == NULL)
1779 return 0;
1780 return this->plt_->entry_count();
1781 }
1782
1783 // Return the offset of the first non-reserved PLT entry.
1784
1785 template<int size>
1786 unsigned int
1787 Target_x86_64<size>::first_plt_entry_offset() const
1788 {
1789 return this->plt_->first_plt_entry_offset();
1790 }
1791
1792 // Return the size of each PLT entry.
1793
1794 template<int size>
1795 unsigned int
1796 Target_x86_64<size>::plt_entry_size() const
1797 {
1798 return this->plt_->get_plt_entry_size();
1799 }
1800
1801 // Create the GOT and PLT sections for an incremental update.
1802
1803 template<int size>
1804 Output_data_got_base*
1805 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
1806 Layout* layout,
1807 unsigned int got_count,
1808 unsigned int plt_count)
1809 {
1810 gold_assert(this->got_ == NULL);
1811
1812 this->got_ = new Output_data_got<64, false>(got_count * 8);
1813 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1814 (elfcpp::SHF_ALLOC
1815 | elfcpp::SHF_WRITE),
1816 this->got_, ORDER_RELRO_LAST,
1817 true);
1818
1819 // Add the three reserved entries.
1820 this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
1821 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1822 (elfcpp::SHF_ALLOC
1823 | elfcpp::SHF_WRITE),
1824 this->got_plt_, ORDER_NON_RELRO_FIRST,
1825 false);
1826
1827 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1828 this->global_offset_table_ =
1829 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1830 Symbol_table::PREDEFINED,
1831 this->got_plt_,
1832 0, 0, elfcpp::STT_OBJECT,
1833 elfcpp::STB_LOCAL,
1834 elfcpp::STV_HIDDEN, 0,
1835 false, false);
1836
1837 // If there are any TLSDESC relocations, they get GOT entries in
1838 // .got.plt after the jump slot entries.
1839 // FIXME: Get the count for TLSDESC entries.
1840 this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1841 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1842 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1843 this->got_tlsdesc_,
1844 ORDER_NON_RELRO_FIRST, false);
1845
1846 // If there are any IRELATIVE relocations, they get GOT entries in
1847 // .got.plt after the jump slot and TLSDESC entries.
1848 this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1849 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1850 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1851 this->got_irelative_,
1852 ORDER_NON_RELRO_FIRST, false);
1853
1854 // Create the PLT section.
1855 this->plt_ = this->make_data_plt(layout, this->got_,
1856 this->got_plt_,
1857 this->got_irelative_,
1858 plt_count);
1859
1860 // Add unwind information if requested.
1861 if (parameters->options().ld_generated_unwind_info())
1862 this->plt_->add_eh_frame(layout);
1863
1864 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1865 elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1866 this->plt_, ORDER_PLT, false);
1867
1868 // Make the sh_info field of .rela.plt point to .plt.
1869 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1870 rela_plt_os->set_info_section(this->plt_->output_section());
1871
1872 // Create the rela_dyn section.
1873 this->rela_dyn_section(layout);
1874
1875 return this->got_;
1876 }
1877
1878 // Reserve a GOT entry for a local symbol, and regenerate any
1879 // necessary dynamic relocations.
1880
1881 template<int size>
1882 void
1883 Target_x86_64<size>::reserve_local_got_entry(
1884 unsigned int got_index,
1885 Sized_relobj<size, false>* obj,
1886 unsigned int r_sym,
1887 unsigned int got_type)
1888 {
1889 unsigned int got_offset = got_index * 8;
1890 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1891
1892 this->got_->reserve_local(got_index, obj, r_sym, got_type);
1893 switch (got_type)
1894 {
1895 case GOT_TYPE_STANDARD:
1896 if (parameters->options().output_is_position_independent())
1897 rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1898 this->got_, got_offset, 0, false);
1899 break;
1900 case GOT_TYPE_TLS_OFFSET:
1901 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1902 this->got_, got_offset, 0);
1903 break;
1904 case GOT_TYPE_TLS_PAIR:
1905 this->got_->reserve_slot(got_index + 1);
1906 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1907 this->got_, got_offset, 0);
1908 break;
1909 case GOT_TYPE_TLS_DESC:
1910 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1911 // this->got_->reserve_slot(got_index + 1);
1912 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1913 // this->got_, got_offset, 0);
1914 break;
1915 default:
1916 gold_unreachable();
1917 }
1918 }
1919
1920 // Reserve a GOT entry for a global symbol, and regenerate any
1921 // necessary dynamic relocations.
1922
1923 template<int size>
1924 void
1925 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
1926 Symbol* gsym,
1927 unsigned int got_type)
1928 {
1929 unsigned int got_offset = got_index * 8;
1930 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1931
1932 this->got_->reserve_global(got_index, gsym, got_type);
1933 switch (got_type)
1934 {
1935 case GOT_TYPE_STANDARD:
1936 if (!gsym->final_value_is_known())
1937 {
1938 if (gsym->is_from_dynobj()
1939 || gsym->is_undefined()
1940 || gsym->is_preemptible()
1941 || gsym->type() == elfcpp::STT_GNU_IFUNC)
1942 rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1943 this->got_, got_offset, 0);
1944 else
1945 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1946 this->got_, got_offset, 0, false);
1947 }
1948 break;
1949 case GOT_TYPE_TLS_OFFSET:
1950 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1951 this->got_, got_offset, 0, false);
1952 break;
1953 case GOT_TYPE_TLS_PAIR:
1954 this->got_->reserve_slot(got_index + 1);
1955 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1956 this->got_, got_offset, 0, false);
1957 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1958 this->got_, got_offset + 8, 0, false);
1959 break;
1960 case GOT_TYPE_TLS_DESC:
1961 this->got_->reserve_slot(got_index + 1);
1962 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
1963 this->got_, got_offset, 0, false);
1964 break;
1965 default:
1966 gold_unreachable();
1967 }
1968 }
1969
1970 // Register an existing PLT entry for a global symbol.
1971
1972 template<int size>
1973 void
1974 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
1975 Layout* layout,
1976 unsigned int plt_index,
1977 Symbol* gsym)
1978 {
1979 gold_assert(this->plt_ != NULL);
1980 gold_assert(!gsym->has_plt_offset());
1981
1982 this->plt_->reserve_slot(plt_index);
1983
1984 gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
1985
1986 unsigned int got_offset = (plt_index + 3) * 8;
1987 this->plt_->add_relocation(symtab, layout, gsym, got_offset);
1988 }
1989
1990 // Force a COPY relocation for a given symbol.
1991
1992 template<int size>
1993 void
1994 Target_x86_64<size>::emit_copy_reloc(
1995 Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
1996 {
1997 this->copy_relocs_.emit_copy_reloc(symtab,
1998 symtab->get_sized_symbol<size>(sym),
1999 os,
2000 offset,
2001 this->rela_dyn_section(NULL));
2002 }
2003
2004 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2005
2006 template<int size>
2007 void
2008 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
2009 Layout* layout)
2010 {
2011 if (this->tls_base_symbol_defined_)
2012 return;
2013
2014 Output_segment* tls_segment = layout->tls_segment();
2015 if (tls_segment != NULL)
2016 {
2017 bool is_exec = parameters->options().output_is_executable();
2018 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
2019 Symbol_table::PREDEFINED,
2020 tls_segment, 0, 0,
2021 elfcpp::STT_TLS,
2022 elfcpp::STB_LOCAL,
2023 elfcpp::STV_HIDDEN, 0,
2024 (is_exec
2025 ? Symbol::SEGMENT_END
2026 : Symbol::SEGMENT_START),
2027 true);
2028 }
2029 this->tls_base_symbol_defined_ = true;
2030 }
2031
2032 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2033
2034 template<int size>
2035 void
2036 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
2037 Layout* layout)
2038 {
2039 if (this->plt_ == NULL)
2040 this->make_plt_section(symtab, layout);
2041
2042 if (!this->plt_->has_tlsdesc_entry())
2043 {
2044 // Allocate the TLSDESC_GOT entry.
2045 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2046 unsigned int got_offset = got->add_constant(0);
2047
2048 // Allocate the TLSDESC_PLT entry.
2049 this->plt_->reserve_tlsdesc_entry(got_offset);
2050 }
2051 }
2052
2053 // Create a GOT entry for the TLS module index.
2054
2055 template<int size>
2056 unsigned int
2057 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2058 Sized_relobj_file<size, false>* object)
2059 {
2060 if (this->got_mod_index_offset_ == -1U)
2061 {
2062 gold_assert(symtab != NULL && layout != NULL && object != NULL);
2063 Reloc_section* rela_dyn = this->rela_dyn_section(layout);
2064 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2065 unsigned int got_offset = got->add_constant(0);
2066 rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
2067 got_offset, 0);
2068 got->add_constant(0);
2069 this->got_mod_index_offset_ = got_offset;
2070 }
2071 return this->got_mod_index_offset_;
2072 }
2073
2074 // Optimize the TLS relocation type based on what we know about the
2075 // symbol. IS_FINAL is true if the final address of this symbol is
2076 // known at link time.
2077
2078 template<int size>
2079 tls::Tls_optimization
2080 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
2081 {
2082 // If we are generating a shared library, then we can't do anything
2083 // in the linker.
2084 if (parameters->options().shared())
2085 return tls::TLSOPT_NONE;
2086
2087 switch (r_type)
2088 {
2089 case elfcpp::R_X86_64_TLSGD:
2090 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2091 case elfcpp::R_X86_64_TLSDESC_CALL:
2092 // These are General-Dynamic which permits fully general TLS
2093 // access. Since we know that we are generating an executable,
2094 // we can convert this to Initial-Exec. If we also know that
2095 // this is a local symbol, we can further switch to Local-Exec.
2096 if (is_final)
2097 return tls::TLSOPT_TO_LE;
2098 return tls::TLSOPT_TO_IE;
2099
2100 case elfcpp::R_X86_64_TLSLD:
2101 // This is Local-Dynamic, which refers to a local symbol in the
2102 // dynamic TLS block. Since we know that we generating an
2103 // executable, we can switch to Local-Exec.
2104 return tls::TLSOPT_TO_LE;
2105
2106 case elfcpp::R_X86_64_DTPOFF32:
2107 case elfcpp::R_X86_64_DTPOFF64:
2108 // Another Local-Dynamic reloc.
2109 return tls::TLSOPT_TO_LE;
2110
2111 case elfcpp::R_X86_64_GOTTPOFF:
2112 // These are Initial-Exec relocs which get the thread offset
2113 // from the GOT. If we know that we are linking against the
2114 // local symbol, we can switch to Local-Exec, which links the
2115 // thread offset into the instruction.
2116 if (is_final)
2117 return tls::TLSOPT_TO_LE;
2118 return tls::TLSOPT_NONE;
2119
2120 case elfcpp::R_X86_64_TPOFF32:
2121 // When we already have Local-Exec, there is nothing further we
2122 // can do.
2123 return tls::TLSOPT_NONE;
2124
2125 default:
2126 gold_unreachable();
2127 }
2128 }
2129
2130 // Get the Reference_flags for a particular relocation.
2131
2132 template<int size>
2133 int
2134 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
2135 {
2136 switch (r_type)
2137 {
2138 case elfcpp::R_X86_64_NONE:
2139 case elfcpp::R_X86_64_GNU_VTINHERIT:
2140 case elfcpp::R_X86_64_GNU_VTENTRY:
2141 case elfcpp::R_X86_64_GOTPC32:
2142 case elfcpp::R_X86_64_GOTPC64:
2143 // No symbol reference.
2144 return 0;
2145
2146 case elfcpp::R_X86_64_64:
2147 case elfcpp::R_X86_64_32:
2148 case elfcpp::R_X86_64_32S:
2149 case elfcpp::R_X86_64_16:
2150 case elfcpp::R_X86_64_8:
2151 return Symbol::ABSOLUTE_REF;
2152
2153 case elfcpp::R_X86_64_PC64:
2154 case elfcpp::R_X86_64_PC32:
2155 case elfcpp::R_X86_64_PC32_BND:
2156 case elfcpp::R_X86_64_PC16:
2157 case elfcpp::R_X86_64_PC8:
2158 case elfcpp::R_X86_64_GOTOFF64:
2159 return Symbol::RELATIVE_REF;
2160
2161 case elfcpp::R_X86_64_PLT32:
2162 case elfcpp::R_X86_64_PLT32_BND:
2163 case elfcpp::R_X86_64_PLTOFF64:
2164 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
2165
2166 case elfcpp::R_X86_64_GOT64:
2167 case elfcpp::R_X86_64_GOT32:
2168 case elfcpp::R_X86_64_GOTPCREL64:
2169 case elfcpp::R_X86_64_GOTPCREL:
2170 case elfcpp::R_X86_64_GOTPLT64:
2171 // Absolute in GOT.
2172 return Symbol::ABSOLUTE_REF;
2173
2174 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2175 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2176 case elfcpp::R_X86_64_TLSDESC_CALL:
2177 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2178 case elfcpp::R_X86_64_DTPOFF32:
2179 case elfcpp::R_X86_64_DTPOFF64:
2180 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2181 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2182 return Symbol::TLS_REF;
2183
2184 case elfcpp::R_X86_64_COPY:
2185 case elfcpp::R_X86_64_GLOB_DAT:
2186 case elfcpp::R_X86_64_JUMP_SLOT:
2187 case elfcpp::R_X86_64_RELATIVE:
2188 case elfcpp::R_X86_64_IRELATIVE:
2189 case elfcpp::R_X86_64_TPOFF64:
2190 case elfcpp::R_X86_64_DTPMOD64:
2191 case elfcpp::R_X86_64_TLSDESC:
2192 case elfcpp::R_X86_64_SIZE32:
2193 case elfcpp::R_X86_64_SIZE64:
2194 default:
2195 // Not expected. We will give an error later.
2196 return 0;
2197 }
2198 }
2199
2200 // Report an unsupported relocation against a local symbol.
2201
2202 template<int size>
2203 void
2204 Target_x86_64<size>::Scan::unsupported_reloc_local(
2205 Sized_relobj_file<size, false>* object,
2206 unsigned int r_type)
2207 {
2208 gold_error(_("%s: unsupported reloc %u against local symbol"),
2209 object->name().c_str(), r_type);
2210 }
2211
2212 // We are about to emit a dynamic relocation of type R_TYPE. If the
2213 // dynamic linker does not support it, issue an error. The GNU linker
2214 // only issues a non-PIC error for an allocated read-only section.
2215 // Here we know the section is allocated, but we don't know that it is
2216 // read-only. But we check for all the relocation types which the
2217 // glibc dynamic linker supports, so it seems appropriate to issue an
2218 // error even if the section is not read-only. If GSYM is not NULL,
2219 // it is the symbol the relocation is against; if it is NULL, the
2220 // relocation is against a local symbol.
2221
2222 template<int size>
2223 void
2224 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
2225 Symbol* gsym)
2226 {
2227 switch (r_type)
2228 {
2229 // These are the relocation types supported by glibc for x86_64
2230 // which should always work.
2231 case elfcpp::R_X86_64_RELATIVE:
2232 case elfcpp::R_X86_64_IRELATIVE:
2233 case elfcpp::R_X86_64_GLOB_DAT:
2234 case elfcpp::R_X86_64_JUMP_SLOT:
2235 case elfcpp::R_X86_64_DTPMOD64:
2236 case elfcpp::R_X86_64_DTPOFF64:
2237 case elfcpp::R_X86_64_TPOFF64:
2238 case elfcpp::R_X86_64_64:
2239 case elfcpp::R_X86_64_COPY:
2240 return;
2241
2242 // glibc supports these reloc types, but they can overflow.
2243 case elfcpp::R_X86_64_PC32:
2244 case elfcpp::R_X86_64_PC32_BND:
2245 // A PC relative reference is OK against a local symbol or if
2246 // the symbol is defined locally.
2247 if (gsym == NULL
2248 || (!gsym->is_from_dynobj()
2249 && !gsym->is_undefined()
2250 && !gsym->is_preemptible()))
2251 return;
2252 /* Fall through. */
2253 case elfcpp::R_X86_64_32:
2254 // R_X86_64_32 is OK for x32.
2255 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2256 return;
2257 if (this->issued_non_pic_error_)
2258 return;
2259 gold_assert(parameters->options().output_is_position_independent());
2260 if (gsym == NULL)
2261 object->error(_("requires dynamic R_X86_64_32 reloc which may "
2262 "overflow at runtime; recompile with -fPIC"));
2263 else
2264 {
2265 const char *r_name;
2266 switch (r_type)
2267 {
2268 case elfcpp::R_X86_64_32:
2269 r_name = "R_X86_64_32";
2270 break;
2271 case elfcpp::R_X86_64_PC32:
2272 r_name = "R_X86_64_PC32";
2273 break;
2274 case elfcpp::R_X86_64_PC32_BND:
2275 r_name = "R_X86_64_PC32_BND";
2276 break;
2277 default:
2278 gold_unreachable();
2279 break;
2280 }
2281 object->error(_("requires dynamic %s reloc against '%s' "
2282 "which may overflow at runtime; recompile "
2283 "with -fPIC"),
2284 r_name, gsym->name());
2285 }
2286 this->issued_non_pic_error_ = true;
2287 return;
2288
2289 default:
2290 // This prevents us from issuing more than one error per reloc
2291 // section. But we can still wind up issuing more than one
2292 // error per object file.
2293 if (this->issued_non_pic_error_)
2294 return;
2295 gold_assert(parameters->options().output_is_position_independent());
2296 object->error(_("requires unsupported dynamic reloc %u; "
2297 "recompile with -fPIC"),
2298 r_type);
2299 this->issued_non_pic_error_ = true;
2300 return;
2301
2302 case elfcpp::R_X86_64_NONE:
2303 gold_unreachable();
2304 }
2305 }
2306
2307 // Return whether we need to make a PLT entry for a relocation of the
2308 // given type against a STT_GNU_IFUNC symbol.
2309
2310 template<int size>
2311 bool
2312 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2313 Sized_relobj_file<size, false>* object,
2314 unsigned int r_type)
2315 {
2316 int flags = Scan::get_reference_flags(r_type);
2317 if (flags & Symbol::TLS_REF)
2318 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2319 object->name().c_str(), r_type);
2320 return flags != 0;
2321 }
2322
2323 // Scan a relocation for a local symbol.
2324
2325 template<int size>
2326 inline void
2327 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2328 Layout* layout,
2329 Target_x86_64<size>* target,
2330 Sized_relobj_file<size, false>* object,
2331 unsigned int data_shndx,
2332 Output_section* output_section,
2333 const elfcpp::Rela<size, false>& reloc,
2334 unsigned int r_type,
2335 const elfcpp::Sym<size, false>& lsym,
2336 bool is_discarded)
2337 {
2338 if (is_discarded)
2339 return;
2340
2341 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2342 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2343 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2344 {
2345 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2346 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2347 }
2348
2349 switch (r_type)
2350 {
2351 case elfcpp::R_X86_64_NONE:
2352 case elfcpp::R_X86_64_GNU_VTINHERIT:
2353 case elfcpp::R_X86_64_GNU_VTENTRY:
2354 break;
2355
2356 case elfcpp::R_X86_64_64:
2357 // If building a shared library (or a position-independent
2358 // executable), we need to create a dynamic relocation for this
2359 // location. The relocation applied at link time will apply the
2360 // link-time value, so we flag the location with an
2361 // R_X86_64_RELATIVE relocation so the dynamic loader can
2362 // relocate it easily.
2363 if (parameters->options().output_is_position_independent())
2364 {
2365 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2366 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2367 rela_dyn->add_local_relative(object, r_sym,
2368 (size == 32
2369 ? elfcpp::R_X86_64_RELATIVE64
2370 : elfcpp::R_X86_64_RELATIVE),
2371 output_section, data_shndx,
2372 reloc.get_r_offset(),
2373 reloc.get_r_addend(), is_ifunc);
2374 }
2375 break;
2376
2377 case elfcpp::R_X86_64_32:
2378 case elfcpp::R_X86_64_32S:
2379 case elfcpp::R_X86_64_16:
2380 case elfcpp::R_X86_64_8:
2381 // If building a shared library (or a position-independent
2382 // executable), we need to create a dynamic relocation for this
2383 // location. We can't use an R_X86_64_RELATIVE relocation
2384 // because that is always a 64-bit relocation.
2385 if (parameters->options().output_is_position_independent())
2386 {
2387 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2388 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2389 {
2390 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2391 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2392 rela_dyn->add_local_relative(object, r_sym,
2393 elfcpp::R_X86_64_RELATIVE,
2394 output_section, data_shndx,
2395 reloc.get_r_offset(),
2396 reloc.get_r_addend(), is_ifunc);
2397 break;
2398 }
2399
2400 this->check_non_pic(object, r_type, NULL);
2401
2402 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2403 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2404 if (lsym.get_st_type() != elfcpp::STT_SECTION)
2405 rela_dyn->add_local(object, r_sym, r_type, output_section,
2406 data_shndx, reloc.get_r_offset(),
2407 reloc.get_r_addend());
2408 else
2409 {
2410 gold_assert(lsym.get_st_value() == 0);
2411 unsigned int shndx = lsym.get_st_shndx();
2412 bool is_ordinary;
2413 shndx = object->adjust_sym_shndx(r_sym, shndx,
2414 &is_ordinary);
2415 if (!is_ordinary)
2416 object->error(_("section symbol %u has bad shndx %u"),
2417 r_sym, shndx);
2418 else
2419 rela_dyn->add_local_section(object, shndx,
2420 r_type, output_section,
2421 data_shndx, reloc.get_r_offset(),
2422 reloc.get_r_addend());
2423 }
2424 }
2425 break;
2426
2427 case elfcpp::R_X86_64_PC64:
2428 case elfcpp::R_X86_64_PC32:
2429 case elfcpp::R_X86_64_PC32_BND:
2430 case elfcpp::R_X86_64_PC16:
2431 case elfcpp::R_X86_64_PC8:
2432 break;
2433
2434 case elfcpp::R_X86_64_PLT32:
2435 case elfcpp::R_X86_64_PLT32_BND:
2436 // Since we know this is a local symbol, we can handle this as a
2437 // PC32 reloc.
2438 break;
2439
2440 case elfcpp::R_X86_64_GOTPC32:
2441 case elfcpp::R_X86_64_GOTOFF64:
2442 case elfcpp::R_X86_64_GOTPC64:
2443 case elfcpp::R_X86_64_PLTOFF64:
2444 // We need a GOT section.
2445 target->got_section(symtab, layout);
2446 // For PLTOFF64, we'd normally want a PLT section, but since we
2447 // know this is a local symbol, no PLT is needed.
2448 break;
2449
2450 case elfcpp::R_X86_64_GOT64:
2451 case elfcpp::R_X86_64_GOT32:
2452 case elfcpp::R_X86_64_GOTPCREL64:
2453 case elfcpp::R_X86_64_GOTPCREL:
2454 case elfcpp::R_X86_64_GOTPLT64:
2455 {
2456 // The symbol requires a GOT entry.
2457 Output_data_got<64, false>* got = target->got_section(symtab, layout);
2458 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2459
2460 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
2461 // lets function pointers compare correctly with shared
2462 // libraries. Otherwise we would need an IRELATIVE reloc.
2463 bool is_new;
2464 if (is_ifunc)
2465 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2466 else
2467 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2468 if (is_new)
2469 {
2470 // If we are generating a shared object, we need to add a
2471 // dynamic relocation for this symbol's GOT entry.
2472 if (parameters->options().output_is_position_independent())
2473 {
2474 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2475 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2476 if (r_type != elfcpp::R_X86_64_GOT32)
2477 {
2478 unsigned int got_offset =
2479 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2480 rela_dyn->add_local_relative(object, r_sym,
2481 elfcpp::R_X86_64_RELATIVE,
2482 got, got_offset, 0, is_ifunc);
2483 }
2484 else
2485 {
2486 this->check_non_pic(object, r_type, NULL);
2487
2488 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2489 rela_dyn->add_local(
2490 object, r_sym, r_type, got,
2491 object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2492 }
2493 }
2494 }
2495 // For GOTPLT64, we'd normally want a PLT section, but since
2496 // we know this is a local symbol, no PLT is needed.
2497 }
2498 break;
2499
2500 case elfcpp::R_X86_64_COPY:
2501 case elfcpp::R_X86_64_GLOB_DAT:
2502 case elfcpp::R_X86_64_JUMP_SLOT:
2503 case elfcpp::R_X86_64_RELATIVE:
2504 case elfcpp::R_X86_64_IRELATIVE:
2505 // These are outstanding tls relocs, which are unexpected when linking
2506 case elfcpp::R_X86_64_TPOFF64:
2507 case elfcpp::R_X86_64_DTPMOD64:
2508 case elfcpp::R_X86_64_TLSDESC:
2509 gold_error(_("%s: unexpected reloc %u in object file"),
2510 object->name().c_str(), r_type);
2511 break;
2512
2513 // These are initial tls relocs, which are expected when linking
2514 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2515 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2516 case elfcpp::R_X86_64_TLSDESC_CALL:
2517 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2518 case elfcpp::R_X86_64_DTPOFF32:
2519 case elfcpp::R_X86_64_DTPOFF64:
2520 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2521 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2522 {
2523 bool output_is_shared = parameters->options().shared();
2524 const tls::Tls_optimization optimized_type
2525 = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
2526 r_type);
2527 switch (r_type)
2528 {
2529 case elfcpp::R_X86_64_TLSGD: // General-dynamic
2530 if (optimized_type == tls::TLSOPT_NONE)
2531 {
2532 // Create a pair of GOT entries for the module index and
2533 // dtv-relative offset.
2534 Output_data_got<64, false>* got
2535 = target->got_section(symtab, layout);
2536 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2537 unsigned int shndx = lsym.get_st_shndx();
2538 bool is_ordinary;
2539 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2540 if (!is_ordinary)
2541 object->error(_("local symbol %u has bad shndx %u"),
2542 r_sym, shndx);
2543 else
2544 got->add_local_pair_with_rel(object, r_sym,
2545 shndx,
2546 GOT_TYPE_TLS_PAIR,
2547 target->rela_dyn_section(layout),
2548 elfcpp::R_X86_64_DTPMOD64);
2549 }
2550 else if (optimized_type != tls::TLSOPT_TO_LE)
2551 unsupported_reloc_local(object, r_type);
2552 break;
2553
2554 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2555 target->define_tls_base_symbol(symtab, layout);
2556 if (optimized_type == tls::TLSOPT_NONE)
2557 {
2558 // Create reserved PLT and GOT entries for the resolver.
2559 target->reserve_tlsdesc_entries(symtab, layout);
2560
2561 // Generate a double GOT entry with an
2562 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
2563 // is resolved lazily, so the GOT entry needs to be in
2564 // an area in .got.plt, not .got. Call got_section to
2565 // make sure the section has been created.
2566 target->got_section(symtab, layout);
2567 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2568 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2569 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2570 {
2571 unsigned int got_offset = got->add_constant(0);
2572 got->add_constant(0);
2573 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2574 got_offset);
2575 Reloc_section* rt = target->rela_tlsdesc_section(layout);
2576 // We store the arguments we need in a vector, and
2577 // use the index into the vector as the parameter
2578 // to pass to the target specific routines.
2579 uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2580 void* arg = reinterpret_cast<void*>(intarg);
2581 rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2582 got, got_offset, 0);
2583 }
2584 }
2585 else if (optimized_type != tls::TLSOPT_TO_LE)
2586 unsupported_reloc_local(object, r_type);
2587 break;
2588
2589 case elfcpp::R_X86_64_TLSDESC_CALL:
2590 break;
2591
2592 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2593 if (optimized_type == tls::TLSOPT_NONE)
2594 {
2595 // Create a GOT entry for the module index.
2596 target->got_mod_index_entry(symtab, layout, object);
2597 }
2598 else if (optimized_type != tls::TLSOPT_TO_LE)
2599 unsupported_reloc_local(object, r_type);
2600 break;
2601
2602 case elfcpp::R_X86_64_DTPOFF32:
2603 case elfcpp::R_X86_64_DTPOFF64:
2604 break;
2605
2606 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2607 layout->set_has_static_tls();
2608 if (optimized_type == tls::TLSOPT_NONE)
2609 {
2610 // Create a GOT entry for the tp-relative offset.
2611 Output_data_got<64, false>* got
2612 = target->got_section(symtab, layout);
2613 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2614 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
2615 target->rela_dyn_section(layout),
2616 elfcpp::R_X86_64_TPOFF64);
2617 }
2618 else if (optimized_type != tls::TLSOPT_TO_LE)
2619 unsupported_reloc_local(object, r_type);
2620 break;
2621
2622 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2623 layout->set_has_static_tls();
2624 if (output_is_shared)
2625 unsupported_reloc_local(object, r_type);
2626 break;
2627
2628 default:
2629 gold_unreachable();
2630 }
2631 }
2632 break;
2633
2634 case elfcpp::R_X86_64_SIZE32:
2635 case elfcpp::R_X86_64_SIZE64:
2636 default:
2637 gold_error(_("%s: unsupported reloc %u against local symbol"),
2638 object->name().c_str(), r_type);
2639 break;
2640 }
2641 }
2642
2643
2644 // Report an unsupported relocation against a global symbol.
2645
2646 template<int size>
2647 void
2648 Target_x86_64<size>::Scan::unsupported_reloc_global(
2649 Sized_relobj_file<size, false>* object,
2650 unsigned int r_type,
2651 Symbol* gsym)
2652 {
2653 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2654 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2655 }
2656
2657 // Returns true if this relocation type could be that of a function pointer.
2658 template<int size>
2659 inline bool
2660 Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
2661 {
2662 switch (r_type)
2663 {
2664 case elfcpp::R_X86_64_64:
2665 case elfcpp::R_X86_64_32:
2666 case elfcpp::R_X86_64_32S:
2667 case elfcpp::R_X86_64_16:
2668 case elfcpp::R_X86_64_8:
2669 case elfcpp::R_X86_64_GOT64:
2670 case elfcpp::R_X86_64_GOT32:
2671 case elfcpp::R_X86_64_GOTPCREL64:
2672 case elfcpp::R_X86_64_GOTPCREL:
2673 case elfcpp::R_X86_64_GOTPLT64:
2674 {
2675 return true;
2676 }
2677 }
2678 return false;
2679 }
2680
2681 // For safe ICF, scan a relocation for a local symbol to check if it
2682 // corresponds to a function pointer being taken. In that case mark
2683 // the function whose pointer was taken as not foldable.
2684
2685 template<int size>
2686 inline bool
2687 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
2688 Symbol_table* ,
2689 Layout* ,
2690 Target_x86_64<size>* ,
2691 Sized_relobj_file<size, false>* ,
2692 unsigned int ,
2693 Output_section* ,
2694 const elfcpp::Rela<size, false>& ,
2695 unsigned int r_type,
2696 const elfcpp::Sym<size, false>&)
2697 {
2698 // When building a shared library, do not fold any local symbols as it is
2699 // not possible to distinguish pointer taken versus a call by looking at
2700 // the relocation types.
2701 return (parameters->options().shared()
2702 || possible_function_pointer_reloc(r_type));
2703 }
2704
2705 // For safe ICF, scan a relocation for a global symbol to check if it
2706 // corresponds to a function pointer being taken. In that case mark
2707 // the function whose pointer was taken as not foldable.
2708
2709 template<int size>
2710 inline bool
2711 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
2712 Symbol_table*,
2713 Layout* ,
2714 Target_x86_64<size>* ,
2715 Sized_relobj_file<size, false>* ,
2716 unsigned int ,
2717 Output_section* ,
2718 const elfcpp::Rela<size, false>& ,
2719 unsigned int r_type,
2720 Symbol* gsym)
2721 {
2722 // When building a shared library, do not fold symbols whose visibility
2723 // is hidden, internal or protected.
2724 return ((parameters->options().shared()
2725 && (gsym->visibility() == elfcpp::STV_INTERNAL
2726 || gsym->visibility() == elfcpp::STV_PROTECTED
2727 || gsym->visibility() == elfcpp::STV_HIDDEN))
2728 || possible_function_pointer_reloc(r_type));
2729 }
2730
2731 // Scan a relocation for a global symbol.
2732
2733 template<int size>
2734 inline void
2735 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
2736 Layout* layout,
2737 Target_x86_64<size>* target,
2738 Sized_relobj_file<size, false>* object,
2739 unsigned int data_shndx,
2740 Output_section* output_section,
2741 const elfcpp::Rela<size, false>& reloc,
2742 unsigned int r_type,
2743 Symbol* gsym)
2744 {
2745 // A STT_GNU_IFUNC symbol may require a PLT entry.
2746 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2747 && this->reloc_needs_plt_for_ifunc(object, r_type))
2748 target->make_plt_entry(symtab, layout, gsym);
2749
2750 switch (r_type)
2751 {
2752 case elfcpp::R_X86_64_NONE:
2753 case elfcpp::R_X86_64_GNU_VTINHERIT:
2754 case elfcpp::R_X86_64_GNU_VTENTRY:
2755 break;
2756
2757 case elfcpp::R_X86_64_64:
2758 case elfcpp::R_X86_64_32:
2759 case elfcpp::R_X86_64_32S:
2760 case elfcpp::R_X86_64_16:
2761 case elfcpp::R_X86_64_8:
2762 {
2763 // Make a PLT entry if necessary.
2764 if (gsym->needs_plt_entry())
2765 {
2766 target->make_plt_entry(symtab, layout, gsym);
2767 // Since this is not a PC-relative relocation, we may be
2768 // taking the address of a function. In that case we need to
2769 // set the entry in the dynamic symbol table to the address of
2770 // the PLT entry.
2771 if (gsym->is_from_dynobj() && !parameters->options().shared())
2772 gsym->set_needs_dynsym_value();
2773 }
2774 // Make a dynamic relocation if necessary.
2775 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2776 {
2777 if (!parameters->options().output_is_position_independent()
2778 && gsym->may_need_copy_reloc())
2779 {
2780 target->copy_reloc(symtab, layout, object,
2781 data_shndx, output_section, gsym, reloc);
2782 }
2783 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2784 || (size == 32 && r_type == elfcpp::R_X86_64_32))
2785 && gsym->type() == elfcpp::STT_GNU_IFUNC
2786 && gsym->can_use_relative_reloc(false)
2787 && !gsym->is_from_dynobj()
2788 && !gsym->is_undefined()
2789 && !gsym->is_preemptible())
2790 {
2791 // Use an IRELATIVE reloc for a locally defined
2792 // STT_GNU_IFUNC symbol. This makes a function
2793 // address in a PIE executable match the address in a
2794 // shared library that it links against.
2795 Reloc_section* rela_dyn =
2796 target->rela_irelative_section(layout);
2797 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2798 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2799 output_section, object,
2800 data_shndx,
2801 reloc.get_r_offset(),
2802 reloc.get_r_addend());
2803 }
2804 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2805 || (size == 32 && r_type == elfcpp::R_X86_64_32))
2806 && gsym->can_use_relative_reloc(false))
2807 {
2808 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2809 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2810 output_section, object,
2811 data_shndx,
2812 reloc.get_r_offset(),
2813 reloc.get_r_addend(), false);
2814 }
2815 else
2816 {
2817 this->check_non_pic(object, r_type, gsym);
2818 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2819 rela_dyn->add_global(gsym, r_type, output_section, object,
2820 data_shndx, reloc.get_r_offset(),
2821 reloc.get_r_addend());
2822 }
2823 }
2824 }
2825 break;
2826
2827 case elfcpp::R_X86_64_PC64:
2828 case elfcpp::R_X86_64_PC32:
2829 case elfcpp::R_X86_64_PC32_BND:
2830 case elfcpp::R_X86_64_PC16:
2831 case elfcpp::R_X86_64_PC8:
2832 {
2833 // Make a PLT entry if necessary.
2834 if (gsym->needs_plt_entry())
2835 target->make_plt_entry(symtab, layout, gsym);
2836 // Make a dynamic relocation if necessary.
2837 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2838 {
2839 if (parameters->options().output_is_executable()
2840 && gsym->may_need_copy_reloc())
2841 {
2842 target->copy_reloc(symtab, layout, object,
2843 data_shndx, output_section, gsym, reloc);
2844 }
2845 else
2846 {
2847 this->check_non_pic(object, r_type, gsym);
2848 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2849 rela_dyn->add_global(gsym, r_type, output_section, object,
2850 data_shndx, reloc.get_r_offset(),
2851 reloc.get_r_addend());
2852 }
2853 }
2854 }
2855 break;
2856
2857 case elfcpp::R_X86_64_GOT64:
2858 case elfcpp::R_X86_64_GOT32:
2859 case elfcpp::R_X86_64_GOTPCREL64:
2860 case elfcpp::R_X86_64_GOTPCREL:
2861 case elfcpp::R_X86_64_GOTPLT64:
2862 {
2863 // The symbol requires a GOT entry.
2864 Output_data_got<64, false>* got = target->got_section(symtab, layout);
2865 if (gsym->final_value_is_known())
2866 {
2867 // For a STT_GNU_IFUNC symbol we want the PLT address.
2868 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2869 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2870 else
2871 got->add_global(gsym, GOT_TYPE_STANDARD);
2872 }
2873 else
2874 {
2875 // If this symbol is not fully resolved, we need to add a
2876 // dynamic relocation for it.
2877 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2878
2879 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2880 //
2881 // 1) The symbol may be defined in some other module.
2882 //
2883 // 2) We are building a shared library and this is a
2884 // protected symbol; using GLOB_DAT means that the dynamic
2885 // linker can use the address of the PLT in the main
2886 // executable when appropriate so that function address
2887 // comparisons work.
2888 //
2889 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2890 // code, again so that function address comparisons work.
2891 if (gsym->is_from_dynobj()
2892 || gsym->is_undefined()
2893 || gsym->is_preemptible()
2894 || (gsym->visibility() == elfcpp::STV_PROTECTED
2895 && parameters->options().shared())
2896 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2897 && parameters->options().output_is_position_independent()))
2898 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
2899 elfcpp::R_X86_64_GLOB_DAT);
2900 else
2901 {
2902 // For a STT_GNU_IFUNC symbol we want to write the PLT
2903 // offset into the GOT, so that function pointer
2904 // comparisons work correctly.
2905 bool is_new;
2906 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2907 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2908 else
2909 {
2910 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2911 // Tell the dynamic linker to use the PLT address
2912 // when resolving relocations.
2913 if (gsym->is_from_dynobj()
2914 && !parameters->options().shared())
2915 gsym->set_needs_dynsym_value();
2916 }
2917 if (is_new)
2918 {
2919 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2920 rela_dyn->add_global_relative(gsym,
2921 elfcpp::R_X86_64_RELATIVE,
2922 got, got_off, 0, false);
2923 }
2924 }
2925 }
2926 // For GOTPLT64, we also need a PLT entry (but only if the
2927 // symbol is not fully resolved).
2928 if (r_type == elfcpp::R_X86_64_GOTPLT64
2929 && !gsym->final_value_is_known())
2930 target->make_plt_entry(symtab, layout, gsym);
2931 }
2932 break;
2933
2934 case elfcpp::R_X86_64_PLT32:
2935 case elfcpp::R_X86_64_PLT32_BND:
2936 // If the symbol is fully resolved, this is just a PC32 reloc.
2937 // Otherwise we need a PLT entry.
2938 if (gsym->final_value_is_known())
2939 break;
2940 // If building a shared library, we can also skip the PLT entry
2941 // if the symbol is defined in the output file and is protected
2942 // or hidden.
2943 if (gsym->is_defined()
2944 && !gsym->is_from_dynobj()
2945 && !gsym->is_preemptible())
2946 break;
2947 target->make_plt_entry(symtab, layout, gsym);
2948 break;
2949
2950 case elfcpp::R_X86_64_GOTPC32:
2951 case elfcpp::R_X86_64_GOTOFF64:
2952 case elfcpp::R_X86_64_GOTPC64:
2953 case elfcpp::R_X86_64_PLTOFF64:
2954 // We need a GOT section.
2955 target->got_section(symtab, layout);
2956 // For PLTOFF64, we also need a PLT entry (but only if the
2957 // symbol is not fully resolved).
2958 if (r_type == elfcpp::R_X86_64_PLTOFF64
2959 && !gsym->final_value_is_known())
2960 target->make_plt_entry(symtab, layout, gsym);
2961 break;
2962
2963 case elfcpp::R_X86_64_COPY:
2964 case elfcpp::R_X86_64_GLOB_DAT:
2965 case elfcpp::R_X86_64_JUMP_SLOT:
2966 case elfcpp::R_X86_64_RELATIVE:
2967 case elfcpp::R_X86_64_IRELATIVE:
2968 // These are outstanding tls relocs, which are unexpected when linking
2969 case elfcpp::R_X86_64_TPOFF64:
2970 case elfcpp::R_X86_64_DTPMOD64:
2971 case elfcpp::R_X86_64_TLSDESC:
2972 gold_error(_("%s: unexpected reloc %u in object file"),
2973 object->name().c_str(), r_type);
2974 break;
2975
2976 // These are initial tls relocs, which are expected for global()
2977 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2978 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2979 case elfcpp::R_X86_64_TLSDESC_CALL:
2980 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2981 case elfcpp::R_X86_64_DTPOFF32:
2982 case elfcpp::R_X86_64_DTPOFF64:
2983 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2984 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2985 {
2986 const bool is_final = gsym->final_value_is_known();
2987 const tls::Tls_optimization optimized_type
2988 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
2989 switch (r_type)
2990 {
2991 case elfcpp::R_X86_64_TLSGD: // General-dynamic
2992 if (optimized_type == tls::TLSOPT_NONE)
2993 {
2994 // Create a pair of GOT entries for the module index and
2995 // dtv-relative offset.
2996 Output_data_got<64, false>* got
2997 = target->got_section(symtab, layout);
2998 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2999 target->rela_dyn_section(layout),
3000 elfcpp::R_X86_64_DTPMOD64,
3001 elfcpp::R_X86_64_DTPOFF64);
3002 }
3003 else if (optimized_type == tls::TLSOPT_TO_IE)
3004 {
3005 // Create a GOT entry for the tp-relative offset.
3006 Output_data_got<64, false>* got
3007 = target->got_section(symtab, layout);
3008 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3009 target->rela_dyn_section(layout),
3010 elfcpp::R_X86_64_TPOFF64);
3011 }
3012 else if (optimized_type != tls::TLSOPT_TO_LE)
3013 unsupported_reloc_global(object, r_type, gsym);
3014 break;
3015
3016 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3017 target->define_tls_base_symbol(symtab, layout);
3018 if (optimized_type == tls::TLSOPT_NONE)
3019 {
3020 // Create reserved PLT and GOT entries for the resolver.
3021 target->reserve_tlsdesc_entries(symtab, layout);
3022
3023 // Create a double GOT entry with an R_X86_64_TLSDESC
3024 // reloc. The R_X86_64_TLSDESC reloc is resolved
3025 // lazily, so the GOT entry needs to be in an area in
3026 // .got.plt, not .got. Call got_section to make sure
3027 // the section has been created.
3028 target->got_section(symtab, layout);
3029 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3030 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3031 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
3032 elfcpp::R_X86_64_TLSDESC, 0);
3033 }
3034 else if (optimized_type == tls::TLSOPT_TO_IE)
3035 {
3036 // Create a GOT entry for the tp-relative offset.
3037 Output_data_got<64, false>* got
3038 = target->got_section(symtab, layout);
3039 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3040 target->rela_dyn_section(layout),
3041 elfcpp::R_X86_64_TPOFF64);
3042 }
3043 else if (optimized_type != tls::TLSOPT_TO_LE)
3044 unsupported_reloc_global(object, r_type, gsym);
3045 break;
3046
3047 case elfcpp::R_X86_64_TLSDESC_CALL:
3048 break;
3049
3050 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3051 if (optimized_type == tls::TLSOPT_NONE)
3052 {
3053 // Create a GOT entry for the module index.
3054 target->got_mod_index_entry(symtab, layout, object);
3055 }
3056 else if (optimized_type != tls::TLSOPT_TO_LE)
3057 unsupported_reloc_global(object, r_type, gsym);
3058 break;
3059
3060 case elfcpp::R_X86_64_DTPOFF32:
3061 case elfcpp::R_X86_64_DTPOFF64:
3062 break;
3063
3064 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3065 layout->set_has_static_tls();
3066 if (optimized_type == tls::TLSOPT_NONE)
3067 {
3068 // Create a GOT entry for the tp-relative offset.
3069 Output_data_got<64, false>* got
3070 = target->got_section(symtab, layout);
3071 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3072 target->rela_dyn_section(layout),
3073 elfcpp::R_X86_64_TPOFF64);
3074 }
3075 else if (optimized_type != tls::TLSOPT_TO_LE)
3076 unsupported_reloc_global(object, r_type, gsym);
3077 break;
3078
3079 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3080 layout->set_has_static_tls();
3081 if (parameters->options().shared())
3082 unsupported_reloc_global(object, r_type, gsym);
3083 break;
3084
3085 default:
3086 gold_unreachable();
3087 }
3088 }
3089 break;
3090
3091 case elfcpp::R_X86_64_SIZE32:
3092 case elfcpp::R_X86_64_SIZE64:
3093 default:
3094 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3095 object->name().c_str(), r_type,
3096 gsym->demangled_name().c_str());
3097 break;
3098 }
3099 }
3100
3101 template<int size>
3102 void
3103 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
3104 Layout* layout,
3105 Sized_relobj_file<size, false>* object,
3106 unsigned int data_shndx,
3107 unsigned int sh_type,
3108 const unsigned char* prelocs,
3109 size_t reloc_count,
3110 Output_section* output_section,
3111 bool needs_special_offset_handling,
3112 size_t local_symbol_count,
3113 const unsigned char* plocal_symbols)
3114 {
3115
3116 if (sh_type == elfcpp::SHT_REL)
3117 {
3118 return;
3119 }
3120
3121 gold::gc_process_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
3122 typename Target_x86_64<size>::Scan,
3123 typename Target_x86_64<size>::Relocatable_size_for_reloc>(
3124 symtab,
3125 layout,
3126 this,
3127 object,
3128 data_shndx,
3129 prelocs,
3130 reloc_count,
3131 output_section,
3132 needs_special_offset_handling,
3133 local_symbol_count,
3134 plocal_symbols);
3135
3136 }
3137 // Scan relocations for a section.
3138
3139 template<int size>
3140 void
3141 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
3142 Layout* layout,
3143 Sized_relobj_file<size, false>* object,
3144 unsigned int data_shndx,
3145 unsigned int sh_type,
3146 const unsigned char* prelocs,
3147 size_t reloc_count,
3148 Output_section* output_section,
3149 bool needs_special_offset_handling,
3150 size_t local_symbol_count,
3151 const unsigned char* plocal_symbols)
3152 {
3153 if (sh_type == elfcpp::SHT_REL)
3154 {
3155 gold_error(_("%s: unsupported REL reloc section"),
3156 object->name().c_str());
3157 return;
3158 }
3159
3160 gold::scan_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
3161 typename Target_x86_64<size>::Scan>(
3162 symtab,
3163 layout,
3164 this,
3165 object,
3166 data_shndx,
3167 prelocs,
3168 reloc_count,
3169 output_section,
3170 needs_special_offset_handling,
3171 local_symbol_count,
3172 plocal_symbols);
3173 }
3174
3175 // Finalize the sections.
3176
3177 template<int size>
3178 void
3179 Target_x86_64<size>::do_finalize_sections(
3180 Layout* layout,
3181 const Input_objects*,
3182 Symbol_table* symtab)
3183 {
3184 const Reloc_section* rel_plt = (this->plt_ == NULL
3185 ? NULL
3186 : this->plt_->rela_plt());
3187 layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
3188 this->rela_dyn_, true, false);
3189
3190 // Fill in some more dynamic tags.
3191 Output_data_dynamic* const odyn = layout->dynamic_data();
3192 if (odyn != NULL)
3193 {
3194 if (this->plt_ != NULL
3195 && this->plt_->output_section() != NULL
3196 && this->plt_->has_tlsdesc_entry())
3197 {
3198 unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
3199 unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
3200 this->got_->finalize_data_size();
3201 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
3202 this->plt_, plt_offset);
3203 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
3204 this->got_, got_offset);
3205 }
3206 }
3207
3208 // Emit any relocs we saved in an attempt to avoid generating COPY
3209 // relocs.
3210 if (this->copy_relocs_.any_saved_relocs())
3211 this->copy_relocs_.emit(this->rela_dyn_section(layout));
3212
3213 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3214 // the .got.plt section.
3215 Symbol* sym = this->global_offset_table_;
3216 if (sym != NULL)
3217 {
3218 uint64_t data_size = this->got_plt_->current_data_size();
3219 symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
3220 }
3221
3222 if (parameters->doing_static_link()
3223 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
3224 {
3225 // If linking statically, make sure that the __rela_iplt symbols
3226 // were defined if necessary, even if we didn't create a PLT.
3227 static const Define_symbol_in_segment syms[] =
3228 {
3229 {
3230 "__rela_iplt_start", // name
3231 elfcpp::PT_LOAD, // segment_type
3232 elfcpp::PF_W, // segment_flags_set
3233 elfcpp::PF(0), // segment_flags_clear
3234 0, // value
3235 0, // size
3236 elfcpp::STT_NOTYPE, // type
3237 elfcpp::STB_GLOBAL, // binding
3238 elfcpp::STV_HIDDEN, // visibility
3239 0, // nonvis
3240 Symbol::SEGMENT_START, // offset_from_base
3241 true // only_if_ref
3242 },
3243 {
3244 "__rela_iplt_end", // name
3245 elfcpp::PT_LOAD, // segment_type
3246 elfcpp::PF_W, // segment_flags_set
3247 elfcpp::PF(0), // segment_flags_clear
3248 0, // value
3249 0, // size
3250 elfcpp::STT_NOTYPE, // type
3251 elfcpp::STB_GLOBAL, // binding
3252 elfcpp::STV_HIDDEN, // visibility
3253 0, // nonvis
3254 Symbol::SEGMENT_START, // offset_from_base
3255 true // only_if_ref
3256 }
3257 };
3258
3259 symtab->define_symbols(layout, 2, syms,
3260 layout->script_options()->saw_sections_clause());
3261 }
3262 }
3263
3264 // Perform a relocation.
3265
3266 template<int size>
3267 inline bool
3268 Target_x86_64<size>::Relocate::relocate(
3269 const Relocate_info<size, false>* relinfo,
3270 Target_x86_64<size>* target,
3271 Output_section*,
3272 size_t relnum,
3273 const elfcpp::Rela<size, false>& rela,
3274 unsigned int r_type,
3275 const Sized_symbol<size>* gsym,
3276 const Symbol_value<size>* psymval,
3277 unsigned char* view,
3278 typename elfcpp::Elf_types<size>::Elf_Addr address,
3279 section_size_type view_size)
3280 {
3281 if (this->skip_call_tls_get_addr_)
3282 {
3283 if ((r_type != elfcpp::R_X86_64_PLT32
3284 && r_type != elfcpp::R_X86_64_PLT32_BND
3285 && r_type != elfcpp::R_X86_64_PC32_BND
3286 && r_type != elfcpp::R_X86_64_PC32)
3287 || gsym == NULL
3288 || strcmp(gsym->name(), "__tls_get_addr") != 0)
3289 {
3290 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3291 _("missing expected TLS relocation"));
3292 }
3293 else
3294 {
3295 this->skip_call_tls_get_addr_ = false;
3296 return false;
3297 }
3298 }
3299
3300 if (view == NULL)
3301 return true;
3302
3303 const Sized_relobj_file<size, false>* object = relinfo->object;
3304
3305 // Pick the value to use for symbols defined in the PLT.
3306 Symbol_value<size> symval;
3307 if (gsym != NULL
3308 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
3309 {
3310 symval.set_output_value(target->plt_address_for_global(gsym));
3311 psymval = &symval;
3312 }
3313 else if (gsym == NULL && psymval->is_ifunc_symbol())
3314 {
3315 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3316 if (object->local_has_plt_offset(r_sym))
3317 {
3318 symval.set_output_value(target->plt_address_for_local(object, r_sym));
3319 psymval = &symval;
3320 }
3321 }
3322
3323 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3324
3325 // Get the GOT offset if needed.
3326 // The GOT pointer points to the end of the GOT section.
3327 // We need to subtract the size of the GOT section to get
3328 // the actual offset to use in the relocation.
3329 bool have_got_offset = false;
3330 unsigned int got_offset = 0;
3331 switch (r_type)
3332 {
3333 case elfcpp::R_X86_64_GOT32:
3334 case elfcpp::R_X86_64_GOT64:
3335 case elfcpp::R_X86_64_GOTPLT64:
3336 case elfcpp::R_X86_64_GOTPCREL:
3337 case elfcpp::R_X86_64_GOTPCREL64:
3338 if (gsym != NULL)
3339 {
3340 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3341 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3342 }
3343 else
3344 {
3345 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3346 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3347 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3348 - target->got_size());
3349 }
3350 have_got_offset = true;
3351 break;
3352
3353 default:
3354 break;
3355 }
3356
3357 switch (r_type)
3358 {
3359 case elfcpp::R_X86_64_NONE:
3360 case elfcpp::R_X86_64_GNU_VTINHERIT:
3361 case elfcpp::R_X86_64_GNU_VTENTRY:
3362 break;
3363
3364 case elfcpp::R_X86_64_64:
3365 Relocate_functions<size, false>::rela64(view, object, psymval, addend);
3366 break;
3367
3368 case elfcpp::R_X86_64_PC64:
3369 Relocate_functions<size, false>::pcrela64(view, object, psymval, addend,
3370 address);
3371 break;
3372
3373 case elfcpp::R_X86_64_32:
3374 // FIXME: we need to verify that value + addend fits into 32 bits:
3375 // uint64_t x = value + addend;
3376 // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
3377 // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
3378 Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3379 break;
3380
3381 case elfcpp::R_X86_64_32S:
3382 // FIXME: we need to verify that value + addend fits into 32 bits:
3383 // int64_t x = value + addend; // note this quantity is signed!
3384 // x == static_cast<int64_t>(static_cast<int32_t>(x))
3385 Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3386 break;
3387
3388 case elfcpp::R_X86_64_PC32:
3389 case elfcpp::R_X86_64_PC32_BND:
3390 Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3391 address);
3392 break;
3393
3394 case elfcpp::R_X86_64_16:
3395 Relocate_functions<size, false>::rela16(view, object, psymval, addend);
3396 break;
3397
3398 case elfcpp::R_X86_64_PC16:
3399 Relocate_functions<size, false>::pcrela16(view, object, psymval, addend,
3400 address);
3401 break;
3402
3403 case elfcpp::R_X86_64_8:
3404 Relocate_functions<size, false>::rela8(view, object, psymval, addend);
3405 break;
3406
3407 case elfcpp::R_X86_64_PC8:
3408 Relocate_functions<size, false>::pcrela8(view, object, psymval, addend,
3409 address);
3410 break;
3411
3412 case elfcpp::R_X86_64_PLT32:
3413 case elfcpp::R_X86_64_PLT32_BND:
3414 gold_assert(gsym == NULL
3415 || gsym->has_plt_offset()
3416 || gsym->final_value_is_known()
3417 || (gsym->is_defined()
3418 && !gsym->is_from_dynobj()
3419 && !gsym->is_preemptible()));
3420 // Note: while this code looks the same as for R_X86_64_PC32, it
3421 // behaves differently because psymval was set to point to
3422 // the PLT entry, rather than the symbol, in Scan::global().
3423 Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3424 address);
3425 break;
3426
3427 case elfcpp::R_X86_64_PLTOFF64:
3428 {
3429 gold_assert(gsym);
3430 gold_assert(gsym->has_plt_offset()
3431 || gsym->final_value_is_known());
3432 typename elfcpp::Elf_types<size>::Elf_Addr got_address;
3433 got_address = target->got_section(NULL, NULL)->address();
3434 Relocate_functions<size, false>::rela64(view, object, psymval,
3435 addend - got_address);
3436 }
3437 break;
3438
3439 case elfcpp::R_X86_64_GOT32:
3440 gold_assert(have_got_offset);
3441 Relocate_functions<size, false>::rela32(view, got_offset, addend);
3442 break;
3443
3444 case elfcpp::R_X86_64_GOTPC32:
3445 {
3446 gold_assert(gsym);
3447 typename elfcpp::Elf_types<size>::Elf_Addr value;
3448 value = target->got_plt_section()->address();
3449 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3450 }
3451 break;
3452
3453 case elfcpp::R_X86_64_GOT64:
3454 // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
3455 // Since we always add a PLT entry, this is equivalent.
3456 case elfcpp::R_X86_64_GOTPLT64:
3457 gold_assert(have_got_offset);
3458 Relocate_functions<size, false>::rela64(view, got_offset, addend);
3459 break;
3460
3461 case elfcpp::R_X86_64_GOTPC64:
3462 {
3463 gold_assert(gsym);
3464 typename elfcpp::Elf_types<size>::Elf_Addr value;
3465 value = target->got_plt_section()->address();
3466 Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3467 }
3468 break;
3469
3470 case elfcpp::R_X86_64_GOTOFF64:
3471 {
3472 typename elfcpp::Elf_types<size>::Elf_Addr value;
3473 value = (psymval->value(object, 0)
3474 - target->got_plt_section()->address());
3475 Relocate_functions<size, false>::rela64(view, value, addend);
3476 }
3477 break;
3478
3479 case elfcpp::R_X86_64_GOTPCREL:
3480 {
3481 gold_assert(have_got_offset);
3482 typename elfcpp::Elf_types<size>::Elf_Addr value;
3483 value = target->got_plt_section()->address() + got_offset;
3484 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3485 }
3486 break;
3487
3488 case elfcpp::R_X86_64_GOTPCREL64:
3489 {
3490 gold_assert(have_got_offset);
3491 typename elfcpp::Elf_types<size>::Elf_Addr value;
3492 value = target->got_plt_section()->address() + got_offset;
3493 Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3494 }
3495 break;
3496
3497 case elfcpp::R_X86_64_COPY:
3498 case elfcpp::R_X86_64_GLOB_DAT:
3499 case elfcpp::R_X86_64_JUMP_SLOT:
3500 case elfcpp::R_X86_64_RELATIVE:
3501 case elfcpp::R_X86_64_IRELATIVE:
3502 // These are outstanding tls relocs, which are unexpected when linking
3503 case elfcpp::R_X86_64_TPOFF64:
3504 case elfcpp::R_X86_64_DTPMOD64:
3505 case elfcpp::R_X86_64_TLSDESC:
3506 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3507 _("unexpected reloc %u in object file"),
3508 r_type);
3509 break;
3510
3511 // These are initial tls relocs, which are expected when linking
3512 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3513 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3514 case elfcpp::R_X86_64_TLSDESC_CALL:
3515 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3516 case elfcpp::R_X86_64_DTPOFF32:
3517 case elfcpp::R_X86_64_DTPOFF64:
3518 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3519 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3520 this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3521 view, address, view_size);
3522 break;
3523
3524 case elfcpp::R_X86_64_SIZE32:
3525 case elfcpp::R_X86_64_SIZE64:
3526 default:
3527 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3528 _("unsupported reloc %u"),
3529 r_type);
3530 break;
3531 }
3532
3533 return true;
3534 }
3535
3536 // Perform a TLS relocation.
3537
3538 template<int size>
3539 inline void
3540 Target_x86_64<size>::Relocate::relocate_tls(
3541 const Relocate_info<size, false>* relinfo,
3542 Target_x86_64<size>* target,
3543 size_t relnum,
3544 const elfcpp::Rela<size, false>& rela,
3545 unsigned int r_type,
3546 const Sized_symbol<size>* gsym,
3547 const Symbol_value<size>* psymval,
3548 unsigned char* view,
3549 typename elfcpp::Elf_types<size>::Elf_Addr address,
3550 section_size_type view_size)
3551 {
3552 Output_segment* tls_segment = relinfo->layout->tls_segment();
3553
3554 const Sized_relobj_file<size, false>* object = relinfo->object;
3555 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3556 elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
3557 bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3558
3559 typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
3560
3561 const bool is_final = (gsym == NULL
3562 ? !parameters->options().shared()
3563 : gsym->final_value_is_known());
3564 tls::Tls_optimization optimized_type
3565 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3566 switch (r_type)
3567 {
3568 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3569 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3570 {
3571 // If this code sequence is used in a non-executable section,
3572 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3573 // on the assumption that it's being used by itself in a debug
3574 // section. Therefore, in the unlikely event that the code
3575 // sequence appears in a non-executable section, we simply
3576 // leave it unoptimized.
3577 optimized_type = tls::TLSOPT_NONE;
3578 }
3579 if (optimized_type == tls::TLSOPT_TO_LE)
3580 {
3581 if (tls_segment == NULL)
3582 {
3583 gold_assert(parameters->errors()->error_count() > 0
3584 || issue_undefined_symbol_error(gsym));
3585 return;
3586 }
3587 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3588 rela, r_type, value, view,
3589 view_size);
3590 break;
3591 }
3592 else
3593 {
3594 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3595 ? GOT_TYPE_TLS_OFFSET
3596 : GOT_TYPE_TLS_PAIR);
3597 unsigned int got_offset;
3598 if (gsym != NULL)
3599 {
3600 gold_assert(gsym->has_got_offset(got_type));
3601 got_offset = gsym->got_offset(got_type) - target->got_size();
3602 }
3603 else
3604 {
3605 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3606 gold_assert(object->local_has_got_offset(r_sym, got_type));
3607 got_offset = (object->local_got_offset(r_sym, got_type)
3608 - target->got_size());
3609 }
3610 if (optimized_type == tls::TLSOPT_TO_IE)
3611 {
3612 value = target->got_plt_section()->address() + got_offset;
3613 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
3614 value, view, address, view_size);
3615 break;
3616 }
3617 else if (optimized_type == tls::TLSOPT_NONE)
3618 {
3619 // Relocate the field with the offset of the pair of GOT
3620 // entries.
3621 value = target->got_plt_section()->address() + got_offset;
3622 Relocate_functions<size, false>::pcrela32(view, value, addend,
3623 address);
3624 break;
3625 }
3626 }
3627 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3628 _("unsupported reloc %u"), r_type);
3629 break;
3630
3631 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3632 case elfcpp::R_X86_64_TLSDESC_CALL:
3633 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3634 {
3635 // See above comment for R_X86_64_TLSGD.
3636 optimized_type = tls::TLSOPT_NONE;
3637 }
3638 if (optimized_type == tls::TLSOPT_TO_LE)
3639 {
3640 if (tls_segment == NULL)
3641 {
3642 gold_assert(parameters->errors()->error_count() > 0
3643 || issue_undefined_symbol_error(gsym));
3644 return;
3645 }
3646 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3647 rela, r_type, value, view,
3648 view_size);
3649 break;
3650 }
3651 else
3652 {
3653 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3654 ? GOT_TYPE_TLS_OFFSET
3655 : GOT_TYPE_TLS_DESC);
3656 unsigned int got_offset = 0;
3657 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3658 && optimized_type == tls::TLSOPT_NONE)
3659 {
3660 // We created GOT entries in the .got.tlsdesc portion of
3661 // the .got.plt section, but the offset stored in the
3662 // symbol is the offset within .got.tlsdesc.
3663 got_offset = (target->got_size()
3664 + target->got_plt_section()->data_size());
3665 }
3666 if (gsym != NULL)
3667 {
3668 gold_assert(gsym->has_got_offset(got_type));
3669 got_offset += gsym->got_offset(got_type) - target->got_size();
3670 }
3671 else
3672 {
3673 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3674 gold_assert(object->local_has_got_offset(r_sym, got_type));
3675 got_offset += (object->local_got_offset(r_sym, got_type)
3676 - target->got_size());
3677 }
3678 if (optimized_type == tls::TLSOPT_TO_IE)
3679 {
3680 if (tls_segment == NULL)
3681 {
3682 gold_assert(parameters->errors()->error_count() > 0
3683 || issue_undefined_symbol_error(gsym));
3684 return;
3685 }
3686 value = target->got_plt_section()->address() + got_offset;
3687 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
3688 rela, r_type, value, view, address,
3689 view_size);
3690 break;
3691 }
3692 else if (optimized_type == tls::TLSOPT_NONE)
3693 {
3694 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3695 {
3696 // Relocate the field with the offset of the pair of GOT
3697 // entries.
3698 value = target->got_plt_section()->address() + got_offset;
3699 Relocate_functions<size, false>::pcrela32(view, value, addend,
3700 address);
3701 }
3702 break;
3703 }
3704 }
3705 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3706 _("unsupported reloc %u"), r_type);
3707 break;
3708
3709 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3710 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3711 {
3712 // See above comment for R_X86_64_TLSGD.
3713 optimized_type = tls::TLSOPT_NONE;
3714 }
3715 if (optimized_type == tls::TLSOPT_TO_LE)
3716 {
3717 if (tls_segment == NULL)
3718 {
3719 gold_assert(parameters->errors()->error_count() > 0
3720 || issue_undefined_symbol_error(gsym));
3721 return;
3722 }
3723 this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3724 value, view, view_size);
3725 break;
3726 }
3727 else if (optimized_type == tls::TLSOPT_NONE)
3728 {
3729 // Relocate the field with the offset of the GOT entry for
3730 // the module index.
3731 unsigned int got_offset;
3732 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3733 - target->got_size());
3734 value = target->got_plt_section()->address() + got_offset;
3735 Relocate_functions<size, false>::pcrela32(view, value, addend,
3736 address);
3737 break;
3738 }
3739 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3740 _("unsupported reloc %u"), r_type);
3741 break;
3742
3743 case elfcpp::R_X86_64_DTPOFF32:
3744 // This relocation type is used in debugging information.
3745 // In that case we need to not optimize the value. If the
3746 // section is not executable, then we assume we should not
3747 // optimize this reloc. See comments above for R_X86_64_TLSGD,
3748 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3749 // R_X86_64_TLSLD.
3750 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3751 {
3752 if (tls_segment == NULL)
3753 {
3754 gold_assert(parameters->errors()->error_count() > 0
3755 || issue_undefined_symbol_error(gsym));
3756 return;
3757 }
3758 value -= tls_segment->memsz();
3759 }
3760 Relocate_functions<size, false>::rela32(view, value, addend);
3761 break;
3762
3763 case elfcpp::R_X86_64_DTPOFF64:
3764 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3765 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3766 {
3767 if (tls_segment == NULL)
3768 {
3769 gold_assert(parameters->errors()->error_count() > 0
3770 || issue_undefined_symbol_error(gsym));
3771 return;
3772 }
3773 value -= tls_segment->memsz();
3774 }
3775 Relocate_functions<size, false>::rela64(view, value, addend);
3776 break;
3777
3778 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3779 if (optimized_type == tls::TLSOPT_TO_LE)
3780 {
3781 if (tls_segment == NULL)
3782 {
3783 gold_assert(parameters->errors()->error_count() > 0
3784 || issue_undefined_symbol_error(gsym));
3785 return;
3786 }
3787 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3788 tls_segment, rela,
3789 r_type, value, view,
3790 view_size);
3791 break;
3792 }
3793 else if (optimized_type == tls::TLSOPT_NONE)
3794 {
3795 // Relocate the field with the offset of the GOT entry for
3796 // the tp-relative offset of the symbol.
3797 unsigned int got_offset;
3798 if (gsym != NULL)
3799 {
3800 gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
3801 got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
3802 - target->got_size());
3803 }
3804 else
3805 {
3806 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3807 gold_assert(object->local_has_got_offset(r_sym,
3808 GOT_TYPE_TLS_OFFSET));
3809 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
3810 - target->got_size());
3811 }
3812 value = target->got_plt_section()->address() + got_offset;
3813 Relocate_functions<size, false>::pcrela32(view, value, addend,
3814 address);
3815 break;
3816 }
3817 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3818 _("unsupported reloc type %u"),
3819 r_type);
3820 break;
3821
3822 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3823 if (tls_segment == NULL)
3824 {
3825 gold_assert(parameters->errors()->error_count() > 0
3826 || issue_undefined_symbol_error(gsym));
3827 return;
3828 }
3829 value -= tls_segment->memsz();
3830 Relocate_functions<size, false>::rela32(view, value, addend);
3831 break;
3832 }
3833 }
3834
3835 // Do a relocation in which we convert a TLS General-Dynamic to an
3836 // Initial-Exec.
3837
3838 template<int size>
3839 inline void
3840 Target_x86_64<size>::Relocate::tls_gd_to_ie(
3841 const Relocate_info<size, false>* relinfo,
3842 size_t relnum,
3843 Output_segment*,
3844 const elfcpp::Rela<size, false>& rela,
3845 unsigned int,
3846 typename elfcpp::Elf_types<size>::Elf_Addr value,
3847 unsigned char* view,
3848 typename elfcpp::Elf_types<size>::Elf_Addr address,
3849 section_size_type view_size)
3850 {
3851 // For SIZE == 64:
3852 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3853 // .word 0x6666; rex64; call __tls_get_addr
3854 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3855 // For SIZE == 32:
3856 // leaq foo@tlsgd(%rip),%rdi;
3857 // .word 0x6666; rex64; call __tls_get_addr
3858 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
3859
3860 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3861 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3862 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3863
3864 if (size == 64)
3865 {
3866 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3867 -4);
3868 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3869 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3870 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
3871 16);
3872 }
3873 else
3874 {
3875 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3876 -3);
3877 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3878 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
3879 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
3880 15);
3881 }
3882
3883 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3884 Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
3885 address);
3886
3887 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3888 // We can skip it.
3889 this->skip_call_tls_get_addr_ = true;
3890 }
3891
3892 // Do a relocation in which we convert a TLS General-Dynamic to a
3893 // Local-Exec.
3894
3895 template<int size>
3896 inline void
3897 Target_x86_64<size>::Relocate::tls_gd_to_le(
3898 const Relocate_info<size, false>* relinfo,
3899 size_t relnum,
3900 Output_segment* tls_segment,
3901 const elfcpp::Rela<size, false>& rela,
3902 unsigned int,
3903 typename elfcpp::Elf_types<size>::Elf_Addr value,
3904 unsigned char* view,
3905 section_size_type view_size)
3906 {
3907 // For SIZE == 64:
3908 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3909 // .word 0x6666; rex64; call __tls_get_addr
3910 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
3911 // For SIZE == 32:
3912 // leaq foo@tlsgd(%rip),%rdi;
3913 // .word 0x6666; rex64; call __tls_get_addr
3914 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
3915
3916 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3917 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3918 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3919
3920 if (size == 64)
3921 {
3922 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3923 -4);
3924 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3925 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3926 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
3927 16);
3928 }
3929 else
3930 {
3931 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
3932 -3);
3933 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3934 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
3935
3936 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
3937 15);
3938 }
3939
3940 value -= tls_segment->memsz();
3941 Relocate_functions<size, false>::rela32(view + 8, value, 0);
3942
3943 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3944 // We can skip it.
3945 this->skip_call_tls_get_addr_ = true;
3946 }
3947
3948 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
3949
3950 template<int size>
3951 inline void
3952 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
3953 const Relocate_info<size, false>* relinfo,
3954 size_t relnum,
3955 Output_segment*,
3956 const elfcpp::Rela<size, false>& rela,
3957 unsigned int r_type,
3958 typename elfcpp::Elf_types<size>::Elf_Addr value,
3959 unsigned char* view,
3960 typename elfcpp::Elf_types<size>::Elf_Addr address,
3961 section_size_type view_size)
3962 {
3963 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3964 {
3965 // leaq foo@tlsdesc(%rip), %rax
3966 // ==> movq foo@gottpoff(%rip), %rax
3967 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3968 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3969 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3970 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
3971 view[-2] = 0x8b;
3972 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3973 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3974 }
3975 else
3976 {
3977 // call *foo@tlscall(%rax)
3978 // ==> nop; nop
3979 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
3980 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
3981 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3982 view[0] == 0xff && view[1] == 0x10);
3983 view[0] = 0x66;
3984 view[1] = 0x90;
3985 }
3986 }
3987
3988 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
3989
3990 template<int size>
3991 inline void
3992 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
3993 const Relocate_info<size, false>* relinfo,
3994 size_t relnum,
3995 Output_segment* tls_segment,
3996 const elfcpp::Rela<size, false>& rela,
3997 unsigned int r_type,
3998 typename elfcpp::Elf_types<size>::Elf_Addr value,
3999 unsigned char* view,
4000 section_size_type view_size)
4001 {
4002 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4003 {
4004 // leaq foo@tlsdesc(%rip), %rax
4005 // ==> movq foo@tpoff, %rax
4006 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4007 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4008 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4009 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4010 view[-2] = 0xc7;
4011 view[-1] = 0xc0;
4012 value -= tls_segment->memsz();
4013 Relocate_functions<size, false>::rela32(view, value, 0);
4014 }
4015 else
4016 {
4017 // call *foo@tlscall(%rax)
4018 // ==> nop; nop
4019 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4020 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4021 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4022 view[0] == 0xff && view[1] == 0x10);
4023 view[0] = 0x66;
4024 view[1] = 0x90;
4025 }
4026 }
4027
4028 template<int size>
4029 inline void
4030 Target_x86_64<size>::Relocate::tls_ld_to_le(
4031 const Relocate_info<size, false>* relinfo,
4032 size_t relnum,
4033 Output_segment*,
4034 const elfcpp::Rela<size, false>& rela,
4035 unsigned int,
4036 typename elfcpp::Elf_types<size>::Elf_Addr,
4037 unsigned char* view,
4038 section_size_type view_size)
4039 {
4040 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4041 // For SIZE == 64:
4042 // ... leq foo@dtpoff(%rax),%reg
4043 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4044 // For SIZE == 32:
4045 // ... leq foo@dtpoff(%rax),%reg
4046 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4047
4048 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4049 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
4050
4051 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4052 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
4053
4054 tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
4055
4056 if (size == 64)
4057 memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4058 else
4059 memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4060
4061 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4062 // We can skip it.
4063 this->skip_call_tls_get_addr_ = true;
4064 }
4065
4066 // Do a relocation in which we convert a TLS Initial-Exec to a
4067 // Local-Exec.
4068
4069 template<int size>
4070 inline void
4071 Target_x86_64<size>::Relocate::tls_ie_to_le(
4072 const Relocate_info<size, false>* relinfo,
4073 size_t relnum,
4074 Output_segment* tls_segment,
4075 const elfcpp::Rela<size, false>& rela,
4076 unsigned int,
4077 typename elfcpp::Elf_types<size>::Elf_Addr value,
4078 unsigned char* view,
4079 section_size_type view_size)
4080 {
4081 // We need to examine the opcodes to figure out which instruction we
4082 // are looking at.
4083
4084 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4085 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4086
4087 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4088 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4089
4090 unsigned char op1 = view[-3];
4091 unsigned char op2 = view[-2];
4092 unsigned char op3 = view[-1];
4093 unsigned char reg = op3 >> 3;
4094
4095 if (op2 == 0x8b)
4096 {
4097 // movq
4098 if (op1 == 0x4c)
4099 view[-3] = 0x49;
4100 view[-2] = 0xc7;
4101 view[-1] = 0xc0 | reg;
4102 }
4103 else if (reg == 4)
4104 {
4105 // Special handling for %rsp.
4106 if (op1 == 0x4c)
4107 view[-3] = 0x49;
4108 view[-2] = 0x81;
4109 view[-1] = 0xc0 | reg;
4110 }
4111 else
4112 {
4113 // addq
4114 if (op1 == 0x4c)
4115 view[-3] = 0x4d;
4116 view[-2] = 0x8d;
4117 view[-1] = 0x80 | reg | (reg << 3);
4118 }
4119
4120 value -= tls_segment->memsz();
4121 Relocate_functions<size, false>::rela32(view, value, 0);
4122 }
4123
4124 // Relocate section data.
4125
4126 template<int size>
4127 void
4128 Target_x86_64<size>::relocate_section(
4129 const Relocate_info<size, false>* relinfo,
4130 unsigned int sh_type,
4131 const unsigned char* prelocs,
4132 size_t reloc_count,
4133 Output_section* output_section,
4134 bool needs_special_offset_handling,
4135 unsigned char* view,
4136 typename elfcpp::Elf_types<size>::Elf_Addr address,
4137 section_size_type view_size,
4138 const Reloc_symbol_changes* reloc_symbol_changes)
4139 {
4140 gold_assert(sh_type == elfcpp::SHT_RELA);
4141
4142 gold::relocate_section<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
4143 typename Target_x86_64<size>::Relocate,
4144 gold::Default_comdat_behavior>(
4145 relinfo,
4146 this,
4147 prelocs,
4148 reloc_count,
4149 output_section,
4150 needs_special_offset_handling,
4151 view,
4152 address,
4153 view_size,
4154 reloc_symbol_changes);
4155 }
4156
4157 // Apply an incremental relocation. Incremental relocations always refer
4158 // to global symbols.
4159
4160 template<int size>
4161 void
4162 Target_x86_64<size>::apply_relocation(
4163 const Relocate_info<size, false>* relinfo,
4164 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
4165 unsigned int r_type,
4166 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
4167 const Symbol* gsym,
4168 unsigned char* view,
4169 typename elfcpp::Elf_types<size>::Elf_Addr address,
4170 section_size_type view_size)
4171 {
4172 gold::apply_relocation<size, false, Target_x86_64<size>,
4173 typename Target_x86_64<size>::Relocate>(
4174 relinfo,
4175 this,
4176 r_offset,
4177 r_type,
4178 r_addend,
4179 gsym,
4180 view,
4181 address,
4182 view_size);
4183 }
4184
4185 // Return the size of a relocation while scanning during a relocatable
4186 // link.
4187
4188 template<int size>
4189 unsigned int
4190 Target_x86_64<size>::Relocatable_size_for_reloc::get_size_for_reloc(
4191 unsigned int r_type,
4192 Relobj* object)
4193 {
4194 switch (r_type)
4195 {
4196 case elfcpp::R_X86_64_NONE:
4197 case elfcpp::R_X86_64_GNU_VTINHERIT:
4198 case elfcpp::R_X86_64_GNU_VTENTRY:
4199 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4200 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4201 case elfcpp::R_X86_64_TLSDESC_CALL:
4202 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4203 case elfcpp::R_X86_64_DTPOFF32:
4204 case elfcpp::R_X86_64_DTPOFF64:
4205 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4206 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4207 return 0;
4208
4209 case elfcpp::R_X86_64_64:
4210 case elfcpp::R_X86_64_PC64:
4211 case elfcpp::R_X86_64_GOTOFF64:
4212 case elfcpp::R_X86_64_GOTPC64:
4213 case elfcpp::R_X86_64_PLTOFF64:
4214 case elfcpp::R_X86_64_GOT64:
4215 case elfcpp::R_X86_64_GOTPCREL64:
4216 case elfcpp::R_X86_64_GOTPCREL:
4217 case elfcpp::R_X86_64_GOTPLT64:
4218 return 8;
4219
4220 case elfcpp::R_X86_64_32:
4221 case elfcpp::R_X86_64_32S:
4222 case elfcpp::R_X86_64_PC32:
4223 case elfcpp::R_X86_64_PC32_BND:
4224 case elfcpp::R_X86_64_PLT32:
4225 case elfcpp::R_X86_64_PLT32_BND:
4226 case elfcpp::R_X86_64_GOTPC32:
4227 case elfcpp::R_X86_64_GOT32:
4228 return 4;
4229
4230 case elfcpp::R_X86_64_16:
4231 case elfcpp::R_X86_64_PC16:
4232 return 2;
4233
4234 case elfcpp::R_X86_64_8:
4235 case elfcpp::R_X86_64_PC8:
4236 return 1;
4237
4238 case elfcpp::R_X86_64_COPY:
4239 case elfcpp::R_X86_64_GLOB_DAT:
4240 case elfcpp::R_X86_64_JUMP_SLOT:
4241 case elfcpp::R_X86_64_RELATIVE:
4242 case elfcpp::R_X86_64_IRELATIVE:
4243 // These are outstanding tls relocs, which are unexpected when linking
4244 case elfcpp::R_X86_64_TPOFF64:
4245 case elfcpp::R_X86_64_DTPMOD64:
4246 case elfcpp::R_X86_64_TLSDESC:
4247 object->error(_("unexpected reloc %u in object file"), r_type);
4248 return 0;
4249
4250 case elfcpp::R_X86_64_SIZE32:
4251 case elfcpp::R_X86_64_SIZE64:
4252 default:
4253 object->error(_("unsupported reloc %u against local symbol"), r_type);
4254 return 0;
4255 }
4256 }
4257
4258 // Scan the relocs during a relocatable link.
4259
4260 template<int size>
4261 void
4262 Target_x86_64<size>::scan_relocatable_relocs(
4263 Symbol_table* symtab,
4264 Layout* layout,
4265 Sized_relobj_file<size, false>* object,
4266 unsigned int data_shndx,
4267 unsigned int sh_type,
4268 const unsigned char* prelocs,
4269 size_t reloc_count,
4270 Output_section* output_section,
4271 bool needs_special_offset_handling,
4272 size_t local_symbol_count,
4273 const unsigned char* plocal_symbols,
4274 Relocatable_relocs* rr)
4275 {
4276 gold_assert(sh_type == elfcpp::SHT_RELA);
4277
4278 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
4279 Relocatable_size_for_reloc> Scan_relocatable_relocs;
4280
4281 gold::scan_relocatable_relocs<size, false, elfcpp::SHT_RELA,
4282 Scan_relocatable_relocs>(
4283 symtab,
4284 layout,
4285 object,
4286 data_shndx,
4287 prelocs,
4288 reloc_count,
4289 output_section,
4290 needs_special_offset_handling,
4291 local_symbol_count,
4292 plocal_symbols,
4293 rr);
4294 }
4295
4296 // Relocate a section during a relocatable link.
4297
4298 template<int size>
4299 void
4300 Target_x86_64<size>::relocate_relocs(
4301 const Relocate_info<size, false>* relinfo,
4302 unsigned int sh_type,
4303 const unsigned char* prelocs,
4304 size_t reloc_count,
4305 Output_section* output_section,
4306 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
4307 const Relocatable_relocs* rr,
4308 unsigned char* view,
4309 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
4310 section_size_type view_size,
4311 unsigned char* reloc_view,
4312 section_size_type reloc_view_size)
4313 {
4314 gold_assert(sh_type == elfcpp::SHT_RELA);
4315
4316 gold::relocate_relocs<size, false, elfcpp::SHT_RELA>(
4317 relinfo,
4318 prelocs,
4319 reloc_count,
4320 output_section,
4321 offset_in_output_section,
4322 rr,
4323 view,
4324 view_address,
4325 view_size,
4326 reloc_view,
4327 reloc_view_size);
4328 }
4329
4330 // Return the value to use for a dynamic which requires special
4331 // treatment. This is how we support equality comparisons of function
4332 // pointers across shared library boundaries, as described in the
4333 // processor specific ABI supplement.
4334
4335 template<int size>
4336 uint64_t
4337 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
4338 {
4339 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
4340 return this->plt_address_for_global(gsym);
4341 }
4342
4343 // Return a string used to fill a code section with nops to take up
4344 // the specified length.
4345
4346 template<int size>
4347 std::string
4348 Target_x86_64<size>::do_code_fill(section_size_type length) const
4349 {
4350 if (length >= 16)
4351 {
4352 // Build a jmpq instruction to skip over the bytes.
4353 unsigned char jmp[5];
4354 jmp[0] = 0xe9;
4355 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
4356 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
4357 + std::string(length - 5, static_cast<char>(0x90)));
4358 }
4359
4360 // Nop sequences of various lengths.
4361 const char nop1[1] = { '\x90' }; // nop
4362 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
4363 const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4364 const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
4365 '\x00'};
4366 const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
4367 '\x00', '\x00' };
4368 const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
4369 '\x44', '\x00', '\x00' };
4370 const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
4371 '\x00', '\x00', '\x00',
4372 '\x00' };
4373 const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
4374 '\x00', '\x00', '\x00',
4375 '\x00', '\x00' };
4376 const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
4377 '\x84', '\x00', '\x00',
4378 '\x00', '\x00', '\x00' };
4379 const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4380 '\x1f', '\x84', '\x00',
4381 '\x00', '\x00', '\x00',
4382 '\x00' };
4383 const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
4384 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4385 '\x00', '\x00', '\x00',
4386 '\x00', '\x00' };
4387 const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
4388 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4389 '\x84', '\x00', '\x00',
4390 '\x00', '\x00', '\x00' };
4391 const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4392 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4393 '\x1f', '\x84', '\x00',
4394 '\x00', '\x00', '\x00',
4395 '\x00' };
4396 const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4397 '\x66', '\x66', '\x2e', // data16
4398 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4399 '\x00', '\x00', '\x00',
4400 '\x00', '\x00' };
4401 const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4402 '\x66', '\x66', '\x66', // data16; data16
4403 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4404 '\x84', '\x00', '\x00',
4405 '\x00', '\x00', '\x00' };
4406
4407 const char* nops[16] = {
4408 NULL,
4409 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
4410 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
4411 };
4412
4413 return std::string(nops[length], length);
4414 }
4415
4416 // Return the addend to use for a target specific relocation. The
4417 // only target specific relocation is R_X86_64_TLSDESC for a local
4418 // symbol. We want to set the addend is the offset of the local
4419 // symbol in the TLS segment.
4420
4421 template<int size>
4422 uint64_t
4423 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
4424 uint64_t) const
4425 {
4426 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
4427 uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
4428 gold_assert(intarg < this->tlsdesc_reloc_info_.size());
4429 const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
4430 const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
4431 gold_assert(psymval->is_tls_symbol());
4432 // The value of a TLS symbol is the offset in the TLS segment.
4433 return psymval->value(ti.object, 0);
4434 }
4435
4436 // Return the value to use for the base of a DW_EH_PE_datarel offset
4437 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
4438 // assembler can not write out the difference between two labels in
4439 // different sections, so instead of using a pc-relative value they
4440 // use an offset from the GOT.
4441
4442 template<int size>
4443 uint64_t
4444 Target_x86_64<size>::do_ehframe_datarel_base() const
4445 {
4446 gold_assert(this->global_offset_table_ != NULL);
4447 Symbol* sym = this->global_offset_table_;
4448 Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
4449 return ssym->value();
4450 }
4451
4452 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4453 // compiled with -fsplit-stack. The function calls non-split-stack
4454 // code. We have to change the function so that it always ensures
4455 // that it has enough stack space to run some random function.
4456
4457 template<int size>
4458 void
4459 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
4460 section_offset_type fnoffset,
4461 section_size_type fnsize,
4462 unsigned char* view,
4463 section_size_type view_size,
4464 std::string* from,
4465 std::string* to) const
4466 {
4467 // The function starts with a comparison of the stack pointer and a
4468 // field in the TCB. This is followed by a jump.
4469
4470 // cmp %fs:NN,%rsp
4471 if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
4472 && fnsize > 9)
4473 {
4474 // We will call __morestack if the carry flag is set after this
4475 // comparison. We turn the comparison into an stc instruction
4476 // and some nops.
4477 view[fnoffset] = '\xf9';
4478 this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
4479 }
4480 // lea NN(%rsp),%r10
4481 // lea NN(%rsp),%r11
4482 else if ((this->match_view(view, view_size, fnoffset,
4483 "\x4c\x8d\x94\x24", 4)
4484 || this->match_view(view, view_size, fnoffset,
4485 "\x4c\x8d\x9c\x24", 4))
4486 && fnsize > 8)
4487 {
4488 // This is loading an offset from the stack pointer for a
4489 // comparison. The offset is negative, so we decrease the
4490 // offset by the amount of space we need for the stack. This
4491 // means we will avoid calling __morestack if there happens to
4492 // be plenty of space on the stack already.
4493 unsigned char* pval = view + fnoffset + 4;
4494 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4495 val -= parameters->options().split_stack_adjust_size();
4496 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4497 }
4498 else
4499 {
4500 if (!object->has_no_split_stack())
4501 object->error(_("failed to match split-stack sequence at "
4502 "section %u offset %0zx"),
4503 shndx, static_cast<size_t>(fnoffset));
4504 return;
4505 }
4506
4507 // We have to change the function so that it calls
4508 // __morestack_non_split instead of __morestack. The former will
4509 // allocate additional stack space.
4510 *from = "__morestack";
4511 *to = "__morestack_non_split";
4512 }
4513
4514 // The selector for x86_64 object files. Note this is never instantiated
4515 // directly. It's only used in Target_selector_x86_64_nacl, below.
4516
4517 template<int size>
4518 class Target_selector_x86_64 : public Target_selector_freebsd
4519 {
4520 public:
4521 Target_selector_x86_64()
4522 : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
4523 (size == 64
4524 ? "elf64-x86-64" : "elf32-x86-64"),
4525 (size == 64
4526 ? "elf64-x86-64-freebsd"
4527 : "elf32-x86-64-freebsd"),
4528 (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
4529 { }
4530
4531 Target*
4532 do_instantiate_target()
4533 { return new Target_x86_64<size>(); }
4534
4535 };
4536
4537 // NaCl variant. It uses different PLT contents.
4538
4539 template<int size>
4540 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
4541 {
4542 public:
4543 Output_data_plt_x86_64_nacl(Layout* layout,
4544 Output_data_got<64, false>* got,
4545 Output_data_got_plt_x86_64* got_plt,
4546 Output_data_space* got_irelative)
4547 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4548 got, got_plt, got_irelative)
4549 { }
4550
4551 Output_data_plt_x86_64_nacl(Layout* layout,
4552 Output_data_got<64, false>* got,
4553 Output_data_got_plt_x86_64* got_plt,
4554 Output_data_space* got_irelative,
4555 unsigned int plt_count)
4556 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4557 got, got_plt, got_irelative,
4558 plt_count)
4559 { }
4560
4561 protected:
4562 virtual unsigned int
4563 do_get_plt_entry_size() const
4564 { return plt_entry_size; }
4565
4566 virtual void
4567 do_add_eh_frame(Layout* layout)
4568 {
4569 layout->add_eh_frame_for_plt(this,
4570 this->plt_eh_frame_cie,
4571 this->plt_eh_frame_cie_size,
4572 plt_eh_frame_fde,
4573 plt_eh_frame_fde_size);
4574 }
4575
4576 virtual void
4577 do_fill_first_plt_entry(unsigned char* pov,
4578 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
4579 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
4580
4581 virtual unsigned int
4582 do_fill_plt_entry(unsigned char* pov,
4583 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4584 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4585 unsigned int got_offset,
4586 unsigned int plt_offset,
4587 unsigned int plt_index);
4588
4589 virtual void
4590 do_fill_tlsdesc_entry(unsigned char* pov,
4591 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4592 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4593 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4594 unsigned int tlsdesc_got_offset,
4595 unsigned int plt_offset);
4596
4597 private:
4598 // The size of an entry in the PLT.
4599 static const int plt_entry_size = 64;
4600
4601 // The first entry in the PLT.
4602 static const unsigned char first_plt_entry[plt_entry_size];
4603
4604 // Other entries in the PLT for an executable.
4605 static const unsigned char plt_entry[plt_entry_size];
4606
4607 // The reserved TLSDESC entry in the PLT for an executable.
4608 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
4609
4610 // The .eh_frame unwind information for the PLT.
4611 static const int plt_eh_frame_fde_size = 32;
4612 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4613 };
4614
4615 template<int size>
4616 class Target_x86_64_nacl : public Target_x86_64<size>
4617 {
4618 public:
4619 Target_x86_64_nacl()
4620 : Target_x86_64<size>(&x86_64_nacl_info)
4621 { }
4622
4623 virtual Output_data_plt_x86_64<size>*
4624 do_make_data_plt(Layout* layout,
4625 Output_data_got<64, false>* got,
4626 Output_data_got_plt_x86_64* got_plt,
4627 Output_data_space* got_irelative)
4628 {
4629 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4630 got_irelative);
4631 }
4632
4633 virtual Output_data_plt_x86_64<size>*
4634 do_make_data_plt(Layout* layout,
4635 Output_data_got<64, false>* got,
4636 Output_data_got_plt_x86_64* got_plt,
4637 Output_data_space* got_irelative,
4638 unsigned int plt_count)
4639 {
4640 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4641 got_irelative,
4642 plt_count);
4643 }
4644
4645 virtual std::string
4646 do_code_fill(section_size_type length) const;
4647
4648 private:
4649 static const Target::Target_info x86_64_nacl_info;
4650 };
4651
4652 template<>
4653 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
4654 {
4655 64, // size
4656 false, // is_big_endian
4657 elfcpp::EM_X86_64, // machine_code
4658 false, // has_make_symbol
4659 false, // has_resolve
4660 true, // has_code_fill
4661 true, // is_default_stack_executable
4662 true, // can_icf_inline_merge_sections
4663 '\0', // wrap_char
4664 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4665 0x20000, // default_text_segment_address
4666 0x10000, // abi_pagesize (overridable by -z max-page-size)
4667 0x10000, // common_pagesize (overridable by -z common-page-size)
4668 true, // isolate_execinstr
4669 0x10000000, // rosegment_gap
4670 elfcpp::SHN_UNDEF, // small_common_shndx
4671 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
4672 0, // small_common_section_flags
4673 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
4674 NULL, // attributes_section
4675 NULL, // attributes_vendor
4676 "_start" // entry_symbol_name
4677 };
4678
4679 template<>
4680 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
4681 {
4682 32, // size
4683 false, // is_big_endian
4684 elfcpp::EM_X86_64, // machine_code
4685 false, // has_make_symbol
4686 false, // has_resolve
4687 true, // has_code_fill
4688 true, // is_default_stack_executable
4689 true, // can_icf_inline_merge_sections
4690 '\0', // wrap_char
4691 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4692 0x20000, // default_text_segment_address
4693 0x10000, // abi_pagesize (overridable by -z max-page-size)
4694 0x10000, // common_pagesize (overridable by -z common-page-size)
4695 true, // isolate_execinstr
4696 0x10000000, // rosegment_gap
4697 elfcpp::SHN_UNDEF, // small_common_shndx
4698 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
4699 0, // small_common_section_flags
4700 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
4701 NULL, // attributes_section
4702 NULL, // attributes_vendor
4703 "_start" // entry_symbol_name
4704 };
4705
4706 #define NACLMASK 0xe0 // 32-byte alignment mask.
4707
4708 // The first entry in the PLT.
4709
4710 template<int size>
4711 const unsigned char
4712 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
4713 {
4714 0xff, 0x35, // pushq contents of memory address
4715 0, 0, 0, 0, // replaced with address of .got + 8
4716 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
4717 0, 0, 0, 0, // replaced with address of .got + 16
4718 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4719 0x4d, 0x01, 0xfb, // add %r15, %r11
4720 0x41, 0xff, 0xe3, // jmpq *%r11
4721
4722 // 9-byte nop sequence to pad out to the next 32-byte boundary.
4723 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4724
4725 // 32 bytes of nop to pad out to the standard size
4726 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4727 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4728 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4729 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4730 0x66, // excess data32 prefix
4731 0x90 // nop
4732 };
4733
4734 template<int size>
4735 void
4736 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
4737 unsigned char* pov,
4738 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4739 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
4740 {
4741 memcpy(pov, first_plt_entry, plt_entry_size);
4742 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4743 (got_address + 8
4744 - (plt_address + 2 + 4)));
4745 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4746 (got_address + 16
4747 - (plt_address + 9 + 4)));
4748 }
4749
4750 // Subsequent entries in the PLT.
4751
4752 template<int size>
4753 const unsigned char
4754 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
4755 {
4756 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
4757 0, 0, 0, 0, // replaced with address of symbol in .got
4758 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4759 0x4d, 0x01, 0xfb, // add %r15, %r11
4760 0x41, 0xff, 0xe3, // jmpq *%r11
4761
4762 // 15-byte nop sequence to pad out to the next 32-byte boundary.
4763 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4764 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4765
4766 // Lazy GOT entries point here (32-byte aligned).
4767 0x68, // pushq immediate
4768 0, 0, 0, 0, // replaced with index into relocation table
4769 0xe9, // jmp relative
4770 0, 0, 0, 0, // replaced with offset to start of .plt0
4771
4772 // 22 bytes of nop to pad out to the standard size.
4773 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4774 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4775 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
4776 };
4777
4778 template<int size>
4779 unsigned int
4780 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
4781 unsigned char* pov,
4782 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4783 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4784 unsigned int got_offset,
4785 unsigned int plt_offset,
4786 unsigned int plt_index)
4787 {
4788 memcpy(pov, plt_entry, plt_entry_size);
4789 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
4790 (got_address + got_offset
4791 - (plt_address + plt_offset
4792 + 3 + 4)));
4793
4794 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
4795 elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
4796 - (plt_offset + 38 + 4));
4797
4798 return 32;
4799 }
4800
4801 // The reserved TLSDESC entry in the PLT.
4802
4803 template<int size>
4804 const unsigned char
4805 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
4806 {
4807 0xff, 0x35, // pushq x(%rip)
4808 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
4809 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
4810 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
4811 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4812 0x4d, 0x01, 0xfb, // add %r15, %r11
4813 0x41, 0xff, 0xe3, // jmpq *%r11
4814
4815 // 41 bytes of nop to pad out to the standard size.
4816 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4817 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4818 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4819 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4820 0x66, 0x66, // excess data32 prefixes
4821 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4822 };
4823
4824 template<int size>
4825 void
4826 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
4827 unsigned char* pov,
4828 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4829 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4830 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4831 unsigned int tlsdesc_got_offset,
4832 unsigned int plt_offset)
4833 {
4834 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
4835 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4836 (got_address + 8
4837 - (plt_address + plt_offset
4838 + 2 + 4)));
4839 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4840 (got_base
4841 + tlsdesc_got_offset
4842 - (plt_address + plt_offset
4843 + 9 + 4)));
4844 }
4845
4846 // The .eh_frame unwind information for the PLT.
4847
4848 template<int size>
4849 const unsigned char
4850 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4851 {
4852 0, 0, 0, 0, // Replaced with offset to .plt.
4853 0, 0, 0, 0, // Replaced with size of .plt.
4854 0, // Augmentation size.
4855 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
4856 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4857 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
4858 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4859 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4860 13, // Block length.
4861 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
4862 elfcpp::DW_OP_breg16, 0, // Push %rip.
4863 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4864 elfcpp::DW_OP_and, // & (%rip & 0x3f).
4865 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4866 elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25)
4867 elfcpp::DW_OP_lit3, // Push 3.
4868 elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3)
4869 elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
4870 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4871 elfcpp::DW_CFA_nop
4872 };
4873
4874 // Return a string used to fill a code section with nops.
4875 // For NaCl, long NOPs are only valid if they do not cross
4876 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4877 template<int size>
4878 std::string
4879 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
4880 {
4881 return std::string(length, static_cast<char>(0x90));
4882 }
4883
4884 // The selector for x86_64-nacl object files.
4885
4886 template<int size>
4887 class Target_selector_x86_64_nacl
4888 : public Target_selector_nacl<Target_selector_x86_64<size>,
4889 Target_x86_64_nacl<size> >
4890 {
4891 public:
4892 Target_selector_x86_64_nacl()
4893 : Target_selector_nacl<Target_selector_x86_64<size>,
4894 Target_x86_64_nacl<size> >("x86-64",
4895 size == 64
4896 ? "elf64-x86-64-nacl"
4897 : "elf32-x86-64-nacl",
4898 size == 64
4899 ? "elf_x86_64_nacl"
4900 : "elf32_x86_64_nacl")
4901 { }
4902 };
4903
4904 Target_selector_x86_64_nacl<64> target_selector_x86_64;
4905 Target_selector_x86_64_nacl<32> target_selector_x32;
4906
4907 } // End anonymous namespace.
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