Add additional information to relocation overflow errors.
[deliverable/binutils-gdb.git] / gold / x86_64.cc
1 // x86_64.cc -- x86_64 target support for gold.
2
3 // Copyright (C) 2006-2016 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 // Scan the relocs for --emit-relocs.
500 void
501 emit_relocs_scan(Symbol_table* symtab,
502 Layout* layout,
503 Sized_relobj_file<size, false>* object,
504 unsigned int data_shndx,
505 unsigned int sh_type,
506 const unsigned char* prelocs,
507 size_t reloc_count,
508 Output_section* output_section,
509 bool needs_special_offset_handling,
510 size_t local_symbol_count,
511 const unsigned char* plocal_syms,
512 Relocatable_relocs* rr);
513
514 // Emit relocations for a section.
515 void
516 relocate_relocs(
517 const Relocate_info<size, false>*,
518 unsigned int sh_type,
519 const unsigned char* prelocs,
520 size_t reloc_count,
521 Output_section* output_section,
522 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
523 unsigned char* view,
524 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
525 section_size_type view_size,
526 unsigned char* reloc_view,
527 section_size_type reloc_view_size);
528
529 // Return a string used to fill a code section with nops.
530 std::string
531 do_code_fill(section_size_type length) const;
532
533 // Return whether SYM is defined by the ABI.
534 bool
535 do_is_defined_by_abi(const Symbol* sym) const
536 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
537
538 // Return the symbol index to use for a target specific relocation.
539 // The only target specific relocation is R_X86_64_TLSDESC for a
540 // local symbol, which is an absolute reloc.
541 unsigned int
542 do_reloc_symbol_index(void*, unsigned int r_type) const
543 {
544 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
545 return 0;
546 }
547
548 // Return the addend to use for a target specific relocation.
549 uint64_t
550 do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
551
552 // Return the PLT section.
553 uint64_t
554 do_plt_address_for_global(const Symbol* gsym) const
555 { return this->plt_section()->address_for_global(gsym); }
556
557 uint64_t
558 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
559 { return this->plt_section()->address_for_local(relobj, symndx); }
560
561 // This function should be defined in targets that can use relocation
562 // types to determine (implemented in local_reloc_may_be_function_pointer
563 // and global_reloc_may_be_function_pointer)
564 // if a function's pointer is taken. ICF uses this in safe mode to only
565 // fold those functions whose pointer is defintely not taken. For x86_64
566 // pie binaries, safe ICF cannot be done by looking at relocation types.
567 bool
568 do_can_check_for_function_pointers() const
569 { return !parameters->options().pie(); }
570
571 // Return the base for a DW_EH_PE_datarel encoding.
572 uint64_t
573 do_ehframe_datarel_base() const;
574
575 // Adjust -fsplit-stack code which calls non-split-stack code.
576 void
577 do_calls_non_split(Relobj* object, unsigned int shndx,
578 section_offset_type fnoffset, section_size_type fnsize,
579 const unsigned char* prelocs, size_t reloc_count,
580 unsigned char* view, section_size_type view_size,
581 std::string* from, std::string* to) const;
582
583 // Return the size of the GOT section.
584 section_size_type
585 got_size() const
586 {
587 gold_assert(this->got_ != NULL);
588 return this->got_->data_size();
589 }
590
591 // Return the number of entries in the GOT.
592 unsigned int
593 got_entry_count() const
594 {
595 if (this->got_ == NULL)
596 return 0;
597 return this->got_size() / 8;
598 }
599
600 // Return the number of entries in the PLT.
601 unsigned int
602 plt_entry_count() const;
603
604 // Return the offset of the first non-reserved PLT entry.
605 unsigned int
606 first_plt_entry_offset() const;
607
608 // Return the size of each PLT entry.
609 unsigned int
610 plt_entry_size() const;
611
612 // Return the size of each GOT entry.
613 unsigned int
614 got_entry_size() const
615 { return 8; };
616
617 // Create the GOT section for an incremental update.
618 Output_data_got_base*
619 init_got_plt_for_update(Symbol_table* symtab,
620 Layout* layout,
621 unsigned int got_count,
622 unsigned int plt_count);
623
624 // Reserve a GOT entry for a local symbol, and regenerate any
625 // necessary dynamic relocations.
626 void
627 reserve_local_got_entry(unsigned int got_index,
628 Sized_relobj<size, false>* obj,
629 unsigned int r_sym,
630 unsigned int got_type);
631
632 // Reserve a GOT entry for a global symbol, and regenerate any
633 // necessary dynamic relocations.
634 void
635 reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
636 unsigned int got_type);
637
638 // Register an existing PLT entry for a global symbol.
639 void
640 register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
641 Symbol* gsym);
642
643 // Force a COPY relocation for a given symbol.
644 void
645 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
646
647 // Apply an incremental relocation.
648 void
649 apply_relocation(const Relocate_info<size, false>* relinfo,
650 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
651 unsigned int r_type,
652 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
653 const Symbol* gsym,
654 unsigned char* view,
655 typename elfcpp::Elf_types<size>::Elf_Addr address,
656 section_size_type view_size);
657
658 // Add a new reloc argument, returning the index in the vector.
659 size_t
660 add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
661 {
662 this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
663 return this->tlsdesc_reloc_info_.size() - 1;
664 }
665
666 Output_data_plt_x86_64<size>*
667 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 this->do_make_data_plt(layout, got, got_plt, got_irelative);
673 }
674
675 Output_data_plt_x86_64<size>*
676 make_data_plt(Layout* layout,
677 Output_data_got<64, false>* got,
678 Output_data_got_plt_x86_64* got_plt,
679 Output_data_space* got_irelative,
680 unsigned int plt_count)
681 {
682 return this->do_make_data_plt(layout, got, got_plt, got_irelative,
683 plt_count);
684 }
685
686 virtual Output_data_plt_x86_64<size>*
687 do_make_data_plt(Layout* layout,
688 Output_data_got<64, false>* got,
689 Output_data_got_plt_x86_64* got_plt,
690 Output_data_space* got_irelative)
691 {
692 return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
693 got_irelative);
694 }
695
696 virtual Output_data_plt_x86_64<size>*
697 do_make_data_plt(Layout* layout,
698 Output_data_got<64, false>* got,
699 Output_data_got_plt_x86_64* got_plt,
700 Output_data_space* got_irelative,
701 unsigned int plt_count)
702 {
703 return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
704 got_irelative,
705 plt_count);
706 }
707
708 private:
709 // The class which scans relocations.
710 class Scan
711 {
712 public:
713 Scan()
714 : issued_non_pic_error_(false)
715 { }
716
717 static inline int
718 get_reference_flags(unsigned int r_type);
719
720 inline void
721 local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
722 Sized_relobj_file<size, false>* object,
723 unsigned int data_shndx,
724 Output_section* output_section,
725 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
726 const elfcpp::Sym<size, false>& lsym,
727 bool is_discarded);
728
729 inline void
730 global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
731 Sized_relobj_file<size, false>* object,
732 unsigned int data_shndx,
733 Output_section* output_section,
734 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
735 Symbol* gsym);
736
737 inline bool
738 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
739 Target_x86_64* target,
740 Sized_relobj_file<size, false>* object,
741 unsigned int data_shndx,
742 Output_section* output_section,
743 const elfcpp::Rela<size, false>& reloc,
744 unsigned int r_type,
745 const elfcpp::Sym<size, false>& lsym);
746
747 inline bool
748 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
749 Target_x86_64* target,
750 Sized_relobj_file<size, false>* object,
751 unsigned int data_shndx,
752 Output_section* output_section,
753 const elfcpp::Rela<size, false>& reloc,
754 unsigned int r_type,
755 Symbol* gsym);
756
757 private:
758 static void
759 unsupported_reloc_local(Sized_relobj_file<size, false>*,
760 unsigned int r_type);
761
762 static void
763 unsupported_reloc_global(Sized_relobj_file<size, false>*,
764 unsigned int r_type, Symbol*);
765
766 void
767 check_non_pic(Relobj*, unsigned int r_type, Symbol*);
768
769 inline bool
770 possible_function_pointer_reloc(unsigned int r_type);
771
772 bool
773 reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
774 unsigned int r_type);
775
776 // Whether we have issued an error about a non-PIC compilation.
777 bool issued_non_pic_error_;
778 };
779
780 // The class which implements relocation.
781 class Relocate
782 {
783 public:
784 Relocate()
785 : skip_call_tls_get_addr_(false)
786 { }
787
788 ~Relocate()
789 {
790 if (this->skip_call_tls_get_addr_)
791 {
792 // FIXME: This needs to specify the location somehow.
793 gold_error(_("missing expected TLS relocation"));
794 }
795 }
796
797 // Do a relocation. Return false if the caller should not issue
798 // any warnings about this relocation.
799 inline bool
800 relocate(const Relocate_info<size, false>*, unsigned int,
801 Target_x86_64*, Output_section*, size_t, const unsigned char*,
802 const Sized_symbol<size>*, const Symbol_value<size>*,
803 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
804 section_size_type);
805
806 private:
807 // Do a TLS relocation.
808 inline void
809 relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
810 size_t relnum, const elfcpp::Rela<size, false>&,
811 unsigned int r_type, const Sized_symbol<size>*,
812 const Symbol_value<size>*,
813 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
814 section_size_type);
815
816 // Do a TLS General-Dynamic to Initial-Exec transition.
817 inline void
818 tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
819 const elfcpp::Rela<size, false>&, unsigned int r_type,
820 typename elfcpp::Elf_types<size>::Elf_Addr value,
821 unsigned char* view,
822 typename elfcpp::Elf_types<size>::Elf_Addr,
823 section_size_type view_size);
824
825 // Do a TLS General-Dynamic to Local-Exec transition.
826 inline void
827 tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
828 Output_segment* tls_segment,
829 const elfcpp::Rela<size, false>&, unsigned int r_type,
830 typename elfcpp::Elf_types<size>::Elf_Addr value,
831 unsigned char* view,
832 section_size_type view_size);
833
834 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
835 inline void
836 tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
837 const elfcpp::Rela<size, false>&, unsigned int r_type,
838 typename elfcpp::Elf_types<size>::Elf_Addr value,
839 unsigned char* view,
840 typename elfcpp::Elf_types<size>::Elf_Addr,
841 section_size_type view_size);
842
843 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
844 inline void
845 tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
846 Output_segment* tls_segment,
847 const elfcpp::Rela<size, false>&, unsigned int r_type,
848 typename elfcpp::Elf_types<size>::Elf_Addr value,
849 unsigned char* view,
850 section_size_type view_size);
851
852 // Do a TLS Local-Dynamic to Local-Exec transition.
853 inline void
854 tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
855 Output_segment* tls_segment,
856 const elfcpp::Rela<size, false>&, unsigned int r_type,
857 typename elfcpp::Elf_types<size>::Elf_Addr value,
858 unsigned char* view,
859 section_size_type view_size);
860
861 // Do a TLS Initial-Exec to Local-Exec transition.
862 static inline void
863 tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
864 Output_segment* tls_segment,
865 const elfcpp::Rela<size, false>&, unsigned int r_type,
866 typename elfcpp::Elf_types<size>::Elf_Addr value,
867 unsigned char* view,
868 section_size_type view_size);
869
870 // This is set if we should skip the next reloc, which should be a
871 // PLT32 reloc against ___tls_get_addr.
872 bool skip_call_tls_get_addr_;
873 };
874
875 // Check if relocation against this symbol is a candidate for
876 // conversion from
877 // mov foo@GOTPCREL(%rip), %reg
878 // to lea foo(%rip), %reg.
879 static bool
880 can_convert_mov_to_lea(const Symbol* gsym)
881 {
882 gold_assert(gsym != NULL);
883 return (gsym->type() != elfcpp::STT_GNU_IFUNC
884 && !gsym->is_undefined ()
885 && !gsym->is_from_dynobj()
886 && !gsym->is_preemptible()
887 && (!parameters->options().shared()
888 || (gsym->visibility() != elfcpp::STV_DEFAULT
889 && gsym->visibility() != elfcpp::STV_PROTECTED)
890 || parameters->options().Bsymbolic())
891 && strcmp(gsym->name(), "_DYNAMIC") != 0);
892 }
893
894 // Adjust TLS relocation type based on the options and whether this
895 // is a local symbol.
896 static tls::Tls_optimization
897 optimize_tls_reloc(bool is_final, int r_type);
898
899 // Get the GOT section, creating it if necessary.
900 Output_data_got<64, false>*
901 got_section(Symbol_table*, Layout*);
902
903 // Get the GOT PLT section.
904 Output_data_got_plt_x86_64*
905 got_plt_section() const
906 {
907 gold_assert(this->got_plt_ != NULL);
908 return this->got_plt_;
909 }
910
911 // Get the GOT section for TLSDESC entries.
912 Output_data_got<64, false>*
913 got_tlsdesc_section() const
914 {
915 gold_assert(this->got_tlsdesc_ != NULL);
916 return this->got_tlsdesc_;
917 }
918
919 // Create the PLT section.
920 void
921 make_plt_section(Symbol_table* symtab, Layout* layout);
922
923 // Create a PLT entry for a global symbol.
924 void
925 make_plt_entry(Symbol_table*, Layout*, Symbol*);
926
927 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
928 void
929 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
930 Sized_relobj_file<size, false>* relobj,
931 unsigned int local_sym_index);
932
933 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
934 void
935 define_tls_base_symbol(Symbol_table*, Layout*);
936
937 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
938 void
939 reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
940
941 // Create a GOT entry for the TLS module index.
942 unsigned int
943 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
944 Sized_relobj_file<size, false>* object);
945
946 // Get the PLT section.
947 Output_data_plt_x86_64<size>*
948 plt_section() const
949 {
950 gold_assert(this->plt_ != NULL);
951 return this->plt_;
952 }
953
954 // Get the dynamic reloc section, creating it if necessary.
955 Reloc_section*
956 rela_dyn_section(Layout*);
957
958 // Get the section to use for TLSDESC relocations.
959 Reloc_section*
960 rela_tlsdesc_section(Layout*) const;
961
962 // Get the section to use for IRELATIVE relocations.
963 Reloc_section*
964 rela_irelative_section(Layout*);
965
966 // Add a potential copy relocation.
967 void
968 copy_reloc(Symbol_table* symtab, Layout* layout,
969 Sized_relobj_file<size, false>* object,
970 unsigned int shndx, Output_section* output_section,
971 Symbol* sym, const elfcpp::Rela<size, false>& reloc)
972 {
973 unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
974 this->copy_relocs_.copy_reloc(symtab, layout,
975 symtab->get_sized_symbol<size>(sym),
976 object, shndx, output_section,
977 r_type, reloc.get_r_offset(),
978 reloc.get_r_addend(),
979 this->rela_dyn_section(layout));
980 }
981
982 // Information about this specific target which we pass to the
983 // general Target structure.
984 static const Target::Target_info x86_64_info;
985
986 // The types of GOT entries needed for this platform.
987 // These values are exposed to the ABI in an incremental link.
988 // Do not renumber existing values without changing the version
989 // number of the .gnu_incremental_inputs section.
990 enum Got_type
991 {
992 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
993 GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
994 GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
995 GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
996 };
997
998 // This type is used as the argument to the target specific
999 // relocation routines. The only target specific reloc is
1000 // R_X86_64_TLSDESC against a local symbol.
1001 struct Tlsdesc_info
1002 {
1003 Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1004 : object(a_object), r_sym(a_r_sym)
1005 { }
1006
1007 // The object in which the local symbol is defined.
1008 Sized_relobj_file<size, false>* object;
1009 // The local symbol index in the object.
1010 unsigned int r_sym;
1011 };
1012
1013 // The GOT section.
1014 Output_data_got<64, false>* got_;
1015 // The PLT section.
1016 Output_data_plt_x86_64<size>* plt_;
1017 // The GOT PLT section.
1018 Output_data_got_plt_x86_64* got_plt_;
1019 // The GOT section for IRELATIVE relocations.
1020 Output_data_space* got_irelative_;
1021 // The GOT section for TLSDESC relocations.
1022 Output_data_got<64, false>* got_tlsdesc_;
1023 // The _GLOBAL_OFFSET_TABLE_ symbol.
1024 Symbol* global_offset_table_;
1025 // The dynamic reloc section.
1026 Reloc_section* rela_dyn_;
1027 // The section to use for IRELATIVE relocs.
1028 Reloc_section* rela_irelative_;
1029 // Relocs saved to avoid a COPY reloc.
1030 Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1031 // Offset of the GOT entry for the TLS module index.
1032 unsigned int got_mod_index_offset_;
1033 // We handle R_X86_64_TLSDESC against a local symbol as a target
1034 // specific relocation. Here we store the object and local symbol
1035 // index for the relocation.
1036 std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1037 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1038 bool tls_base_symbol_defined_;
1039 };
1040
1041 template<>
1042 const Target::Target_info Target_x86_64<64>::x86_64_info =
1043 {
1044 64, // size
1045 false, // is_big_endian
1046 elfcpp::EM_X86_64, // machine_code
1047 false, // has_make_symbol
1048 false, // has_resolve
1049 true, // has_code_fill
1050 true, // is_default_stack_executable
1051 true, // can_icf_inline_merge_sections
1052 '\0', // wrap_char
1053 "/lib/ld64.so.1", // program interpreter
1054 0x400000, // default_text_segment_address
1055 0x1000, // abi_pagesize (overridable by -z max-page-size)
1056 0x1000, // common_pagesize (overridable by -z common-page-size)
1057 false, // isolate_execinstr
1058 0, // rosegment_gap
1059 elfcpp::SHN_UNDEF, // small_common_shndx
1060 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1061 0, // small_common_section_flags
1062 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1063 NULL, // attributes_section
1064 NULL, // attributes_vendor
1065 "_start", // entry_symbol_name
1066 32, // hash_entry_size
1067 };
1068
1069 template<>
1070 const Target::Target_info Target_x86_64<32>::x86_64_info =
1071 {
1072 32, // size
1073 false, // is_big_endian
1074 elfcpp::EM_X86_64, // machine_code
1075 false, // has_make_symbol
1076 false, // has_resolve
1077 true, // has_code_fill
1078 true, // is_default_stack_executable
1079 true, // can_icf_inline_merge_sections
1080 '\0', // wrap_char
1081 "/libx32/ldx32.so.1", // program interpreter
1082 0x400000, // default_text_segment_address
1083 0x1000, // abi_pagesize (overridable by -z max-page-size)
1084 0x1000, // common_pagesize (overridable by -z common-page-size)
1085 false, // isolate_execinstr
1086 0, // rosegment_gap
1087 elfcpp::SHN_UNDEF, // small_common_shndx
1088 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1089 0, // small_common_section_flags
1090 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1091 NULL, // attributes_section
1092 NULL, // attributes_vendor
1093 "_start", // entry_symbol_name
1094 32, // hash_entry_size
1095 };
1096
1097 // This is called when a new output section is created. This is where
1098 // we handle the SHF_X86_64_LARGE.
1099
1100 template<int size>
1101 void
1102 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1103 {
1104 if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1105 os->set_is_large_section();
1106 }
1107
1108 // Get the GOT section, creating it if necessary.
1109
1110 template<int size>
1111 Output_data_got<64, false>*
1112 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1113 {
1114 if (this->got_ == NULL)
1115 {
1116 gold_assert(symtab != NULL && layout != NULL);
1117
1118 // When using -z now, we can treat .got.plt as a relro section.
1119 // Without -z now, it is modified after program startup by lazy
1120 // PLT relocations.
1121 bool is_got_plt_relro = parameters->options().now();
1122 Output_section_order got_order = (is_got_plt_relro
1123 ? ORDER_RELRO
1124 : ORDER_RELRO_LAST);
1125 Output_section_order got_plt_order = (is_got_plt_relro
1126 ? ORDER_RELRO
1127 : ORDER_NON_RELRO_FIRST);
1128
1129 this->got_ = new Output_data_got<64, false>();
1130
1131 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1132 (elfcpp::SHF_ALLOC
1133 | elfcpp::SHF_WRITE),
1134 this->got_, got_order, true);
1135
1136 this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1137 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1138 (elfcpp::SHF_ALLOC
1139 | elfcpp::SHF_WRITE),
1140 this->got_plt_, got_plt_order,
1141 is_got_plt_relro);
1142
1143 // The first three entries are reserved.
1144 this->got_plt_->set_current_data_size(3 * 8);
1145
1146 if (!is_got_plt_relro)
1147 {
1148 // Those bytes can go into the relro segment.
1149 layout->increase_relro(3 * 8);
1150 }
1151
1152 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1153 this->global_offset_table_ =
1154 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1155 Symbol_table::PREDEFINED,
1156 this->got_plt_,
1157 0, 0, elfcpp::STT_OBJECT,
1158 elfcpp::STB_LOCAL,
1159 elfcpp::STV_HIDDEN, 0,
1160 false, false);
1161
1162 // If there are any IRELATIVE relocations, they get GOT entries
1163 // in .got.plt after the jump slot entries.
1164 this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1165 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1166 (elfcpp::SHF_ALLOC
1167 | elfcpp::SHF_WRITE),
1168 this->got_irelative_,
1169 got_plt_order, is_got_plt_relro);
1170
1171 // If there are any TLSDESC relocations, they get GOT entries in
1172 // .got.plt after the jump slot and IRELATIVE entries.
1173 this->got_tlsdesc_ = new Output_data_got<64, false>();
1174 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1175 (elfcpp::SHF_ALLOC
1176 | elfcpp::SHF_WRITE),
1177 this->got_tlsdesc_,
1178 got_plt_order, is_got_plt_relro);
1179 }
1180
1181 return this->got_;
1182 }
1183
1184 // Get the dynamic reloc section, creating it if necessary.
1185
1186 template<int size>
1187 typename Target_x86_64<size>::Reloc_section*
1188 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1189 {
1190 if (this->rela_dyn_ == NULL)
1191 {
1192 gold_assert(layout != NULL);
1193 this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1194 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1195 elfcpp::SHF_ALLOC, this->rela_dyn_,
1196 ORDER_DYNAMIC_RELOCS, false);
1197 }
1198 return this->rela_dyn_;
1199 }
1200
1201 // Get the section to use for IRELATIVE relocs, creating it if
1202 // necessary. These go in .rela.dyn, but only after all other dynamic
1203 // relocations. They need to follow the other dynamic relocations so
1204 // that they can refer to global variables initialized by those
1205 // relocs.
1206
1207 template<int size>
1208 typename Target_x86_64<size>::Reloc_section*
1209 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1210 {
1211 if (this->rela_irelative_ == NULL)
1212 {
1213 // Make sure we have already created the dynamic reloc section.
1214 this->rela_dyn_section(layout);
1215 this->rela_irelative_ = new Reloc_section(false);
1216 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1217 elfcpp::SHF_ALLOC, this->rela_irelative_,
1218 ORDER_DYNAMIC_RELOCS, false);
1219 gold_assert(this->rela_dyn_->output_section()
1220 == this->rela_irelative_->output_section());
1221 }
1222 return this->rela_irelative_;
1223 }
1224
1225 // Write the first three reserved words of the .got.plt section.
1226 // The remainder of the section is written while writing the PLT
1227 // in Output_data_plt_i386::do_write.
1228
1229 void
1230 Output_data_got_plt_x86_64::do_write(Output_file* of)
1231 {
1232 // The first entry in the GOT is the address of the .dynamic section
1233 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1234 // We saved space for them when we created the section in
1235 // Target_x86_64::got_section.
1236 const off_t got_file_offset = this->offset();
1237 gold_assert(this->data_size() >= 24);
1238 unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1239 Output_section* dynamic = this->layout_->dynamic_section();
1240 uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1241 elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1242 memset(got_view + 8, 0, 16);
1243 of->write_output_view(got_file_offset, 24, got_view);
1244 }
1245
1246 // Initialize the PLT section.
1247
1248 template<int size>
1249 void
1250 Output_data_plt_x86_64<size>::init(Layout* layout)
1251 {
1252 this->rel_ = new Reloc_section(false);
1253 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1254 elfcpp::SHF_ALLOC, this->rel_,
1255 ORDER_DYNAMIC_PLT_RELOCS, false);
1256 }
1257
1258 template<int size>
1259 void
1260 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1261 {
1262 os->set_entsize(this->get_plt_entry_size());
1263 }
1264
1265 // Add an entry to the PLT.
1266
1267 template<int size>
1268 void
1269 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1270 Symbol* gsym)
1271 {
1272 gold_assert(!gsym->has_plt_offset());
1273
1274 unsigned int plt_index;
1275 off_t plt_offset;
1276 section_offset_type got_offset;
1277
1278 unsigned int* pcount;
1279 unsigned int offset;
1280 unsigned int reserved;
1281 Output_section_data_build* got;
1282 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1283 && gsym->can_use_relative_reloc(false))
1284 {
1285 pcount = &this->irelative_count_;
1286 offset = 0;
1287 reserved = 0;
1288 got = this->got_irelative_;
1289 }
1290 else
1291 {
1292 pcount = &this->count_;
1293 offset = 1;
1294 reserved = 3;
1295 got = this->got_plt_;
1296 }
1297
1298 if (!this->is_data_size_valid())
1299 {
1300 // Note that when setting the PLT offset for a non-IRELATIVE
1301 // entry we skip the initial reserved PLT entry.
1302 plt_index = *pcount + offset;
1303 plt_offset = plt_index * this->get_plt_entry_size();
1304
1305 ++*pcount;
1306
1307 got_offset = (plt_index - offset + reserved) * 8;
1308 gold_assert(got_offset == got->current_data_size());
1309
1310 // Every PLT entry needs a GOT entry which points back to the PLT
1311 // entry (this will be changed by the dynamic linker, normally
1312 // lazily when the function is called).
1313 got->set_current_data_size(got_offset + 8);
1314 }
1315 else
1316 {
1317 // FIXME: This is probably not correct for IRELATIVE relocs.
1318
1319 // For incremental updates, find an available slot.
1320 plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1321 this->get_plt_entry_size(), 0);
1322 if (plt_offset == -1)
1323 gold_fallback(_("out of patch space (PLT);"
1324 " relink with --incremental-full"));
1325
1326 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1327 // can be calculated from the PLT index, adjusting for the three
1328 // reserved entries at the beginning of the GOT.
1329 plt_index = plt_offset / this->get_plt_entry_size() - 1;
1330 got_offset = (plt_index - offset + reserved) * 8;
1331 }
1332
1333 gsym->set_plt_offset(plt_offset);
1334
1335 // Every PLT entry needs a reloc.
1336 this->add_relocation(symtab, layout, gsym, got_offset);
1337
1338 // Note that we don't need to save the symbol. The contents of the
1339 // PLT are independent of which symbols are used. The symbols only
1340 // appear in the relocations.
1341 }
1342
1343 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1344 // the PLT offset.
1345
1346 template<int size>
1347 unsigned int
1348 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1349 Symbol_table* symtab,
1350 Layout* layout,
1351 Sized_relobj_file<size, false>* relobj,
1352 unsigned int local_sym_index)
1353 {
1354 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1355 ++this->irelative_count_;
1356
1357 section_offset_type got_offset = this->got_irelative_->current_data_size();
1358
1359 // Every PLT entry needs a GOT entry which points back to the PLT
1360 // entry.
1361 this->got_irelative_->set_current_data_size(got_offset + 8);
1362
1363 // Every PLT entry needs a reloc.
1364 Reloc_section* rela = this->rela_irelative(symtab, layout);
1365 rela->add_symbolless_local_addend(relobj, local_sym_index,
1366 elfcpp::R_X86_64_IRELATIVE,
1367 this->got_irelative_, got_offset, 0);
1368
1369 return plt_offset;
1370 }
1371
1372 // Add the relocation for a PLT entry.
1373
1374 template<int size>
1375 void
1376 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1377 Layout* layout,
1378 Symbol* gsym,
1379 unsigned int got_offset)
1380 {
1381 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1382 && gsym->can_use_relative_reloc(false))
1383 {
1384 Reloc_section* rela = this->rela_irelative(symtab, layout);
1385 rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1386 this->got_irelative_, got_offset, 0);
1387 }
1388 else
1389 {
1390 gsym->set_needs_dynsym_entry();
1391 this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1392 got_offset, 0);
1393 }
1394 }
1395
1396 // Return where the TLSDESC relocations should go, creating it if
1397 // necessary. These follow the JUMP_SLOT relocations.
1398
1399 template<int size>
1400 typename Output_data_plt_x86_64<size>::Reloc_section*
1401 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1402 {
1403 if (this->tlsdesc_rel_ == NULL)
1404 {
1405 this->tlsdesc_rel_ = new Reloc_section(false);
1406 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1407 elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1408 ORDER_DYNAMIC_PLT_RELOCS, false);
1409 gold_assert(this->tlsdesc_rel_->output_section()
1410 == this->rel_->output_section());
1411 }
1412 return this->tlsdesc_rel_;
1413 }
1414
1415 // Return where the IRELATIVE relocations should go in the PLT. These
1416 // follow the JUMP_SLOT and the TLSDESC relocations.
1417
1418 template<int size>
1419 typename Output_data_plt_x86_64<size>::Reloc_section*
1420 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1421 Layout* layout)
1422 {
1423 if (this->irelative_rel_ == NULL)
1424 {
1425 // Make sure we have a place for the TLSDESC relocations, in
1426 // case we see any later on.
1427 this->rela_tlsdesc(layout);
1428 this->irelative_rel_ = new Reloc_section(false);
1429 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1430 elfcpp::SHF_ALLOC, this->irelative_rel_,
1431 ORDER_DYNAMIC_PLT_RELOCS, false);
1432 gold_assert(this->irelative_rel_->output_section()
1433 == this->rel_->output_section());
1434
1435 if (parameters->doing_static_link())
1436 {
1437 // A statically linked executable will only have a .rela.plt
1438 // section to hold R_X86_64_IRELATIVE relocs for
1439 // STT_GNU_IFUNC symbols. The library will use these
1440 // symbols to locate the IRELATIVE relocs at program startup
1441 // time.
1442 symtab->define_in_output_data("__rela_iplt_start", NULL,
1443 Symbol_table::PREDEFINED,
1444 this->irelative_rel_, 0, 0,
1445 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1446 elfcpp::STV_HIDDEN, 0, false, true);
1447 symtab->define_in_output_data("__rela_iplt_end", NULL,
1448 Symbol_table::PREDEFINED,
1449 this->irelative_rel_, 0, 0,
1450 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1451 elfcpp::STV_HIDDEN, 0, true, true);
1452 }
1453 }
1454 return this->irelative_rel_;
1455 }
1456
1457 // Return the PLT address to use for a global symbol.
1458
1459 template<int size>
1460 uint64_t
1461 Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
1462 {
1463 uint64_t offset = 0;
1464 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1465 && gsym->can_use_relative_reloc(false))
1466 offset = (this->count_ + 1) * this->get_plt_entry_size();
1467 return this->address() + offset + gsym->plt_offset();
1468 }
1469
1470 // Return the PLT address to use for a local symbol. These are always
1471 // IRELATIVE relocs.
1472
1473 template<int size>
1474 uint64_t
1475 Output_data_plt_x86_64<size>::address_for_local(const Relobj* object,
1476 unsigned int r_sym)
1477 {
1478 return (this->address()
1479 + (this->count_ + 1) * this->get_plt_entry_size()
1480 + object->local_plt_offset(r_sym));
1481 }
1482
1483 // Set the final size.
1484 template<int size>
1485 void
1486 Output_data_plt_x86_64<size>::set_final_data_size()
1487 {
1488 unsigned int count = this->count_ + this->irelative_count_;
1489 if (this->has_tlsdesc_entry())
1490 ++count;
1491 this->set_data_size((count + 1) * this->get_plt_entry_size());
1492 }
1493
1494 // The first entry in the PLT for an executable.
1495
1496 template<int size>
1497 const unsigned char
1498 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1499 {
1500 // From AMD64 ABI Draft 0.98, page 76
1501 0xff, 0x35, // pushq contents of memory address
1502 0, 0, 0, 0, // replaced with address of .got + 8
1503 0xff, 0x25, // jmp indirect
1504 0, 0, 0, 0, // replaced with address of .got + 16
1505 0x90, 0x90, 0x90, 0x90 // noop (x4)
1506 };
1507
1508 template<int size>
1509 void
1510 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1511 unsigned char* pov,
1512 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1513 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1514 {
1515 memcpy(pov, first_plt_entry, plt_entry_size);
1516 // We do a jmp relative to the PC at the end of this instruction.
1517 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1518 (got_address + 8
1519 - (plt_address + 6)));
1520 elfcpp::Swap<32, false>::writeval(pov + 8,
1521 (got_address + 16
1522 - (plt_address + 12)));
1523 }
1524
1525 // Subsequent entries in the PLT for an executable.
1526
1527 template<int size>
1528 const unsigned char
1529 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1530 {
1531 // From AMD64 ABI Draft 0.98, page 76
1532 0xff, 0x25, // jmpq indirect
1533 0, 0, 0, 0, // replaced with address of symbol in .got
1534 0x68, // pushq immediate
1535 0, 0, 0, 0, // replaced with offset into relocation table
1536 0xe9, // jmpq relative
1537 0, 0, 0, 0 // replaced with offset to start of .plt
1538 };
1539
1540 template<int size>
1541 unsigned int
1542 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1543 unsigned char* pov,
1544 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1545 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1546 unsigned int got_offset,
1547 unsigned int plt_offset,
1548 unsigned int plt_index)
1549 {
1550 // Check PC-relative offset overflow in PLT entry.
1551 uint64_t plt_got_pcrel_offset = (got_address + got_offset
1552 - (plt_address + plt_offset + 6));
1553 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1554 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1555 plt_index + 1);
1556
1557 memcpy(pov, plt_entry, plt_entry_size);
1558 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1559 plt_got_pcrel_offset);
1560
1561 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1562 elfcpp::Swap<32, false>::writeval(pov + 12,
1563 - (plt_offset + plt_entry_size));
1564
1565 return 6;
1566 }
1567
1568 // The reserved TLSDESC entry in the PLT for an executable.
1569
1570 template<int size>
1571 const unsigned char
1572 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
1573 {
1574 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1575 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1576 0xff, 0x35, // pushq x(%rip)
1577 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1578 0xff, 0x25, // jmpq *y(%rip)
1579 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1580 0x0f, 0x1f, // nop
1581 0x40, 0
1582 };
1583
1584 template<int size>
1585 void
1586 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
1587 unsigned char* pov,
1588 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1589 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1590 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
1591 unsigned int tlsdesc_got_offset,
1592 unsigned int plt_offset)
1593 {
1594 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1595 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1596 (got_address + 8
1597 - (plt_address + plt_offset
1598 + 6)));
1599 elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1600 (got_base
1601 + tlsdesc_got_offset
1602 - (plt_address + plt_offset
1603 + 12)));
1604 }
1605
1606 // The .eh_frame unwind information for the PLT.
1607
1608 template<int size>
1609 const unsigned char
1610 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1611 {
1612 1, // CIE version.
1613 'z', // Augmentation: augmentation size included.
1614 'R', // Augmentation: FDE encoding included.
1615 '\0', // End of augmentation string.
1616 1, // Code alignment factor.
1617 0x78, // Data alignment factor.
1618 16, // Return address column.
1619 1, // Augmentation size.
1620 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1621 | elfcpp::DW_EH_PE_sdata4),
1622 elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1623 elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1624 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1625 elfcpp::DW_CFA_nop
1626 };
1627
1628 template<int size>
1629 const unsigned char
1630 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1631 {
1632 0, 0, 0, 0, // Replaced with offset to .plt.
1633 0, 0, 0, 0, // Replaced with size of .plt.
1634 0, // Augmentation size.
1635 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
1636 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1637 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
1638 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1639 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1640 11, // Block length.
1641 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
1642 elfcpp::DW_OP_breg16, 0, // Push %rip.
1643 elfcpp::DW_OP_lit15, // Push 0xf.
1644 elfcpp::DW_OP_and, // & (%rip & 0xf).
1645 elfcpp::DW_OP_lit11, // Push 0xb.
1646 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
1647 elfcpp::DW_OP_lit3, // Push 3.
1648 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
1649 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1650 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1651 elfcpp::DW_CFA_nop,
1652 elfcpp::DW_CFA_nop,
1653 elfcpp::DW_CFA_nop
1654 };
1655
1656 // Write out the PLT. This uses the hand-coded instructions above,
1657 // and adjusts them as needed. This is specified by the AMD64 ABI.
1658
1659 template<int size>
1660 void
1661 Output_data_plt_x86_64<size>::do_write(Output_file* of)
1662 {
1663 const off_t offset = this->offset();
1664 const section_size_type oview_size =
1665 convert_to_section_size_type(this->data_size());
1666 unsigned char* const oview = of->get_output_view(offset, oview_size);
1667
1668 const off_t got_file_offset = this->got_plt_->offset();
1669 gold_assert(parameters->incremental_update()
1670 || (got_file_offset + this->got_plt_->data_size()
1671 == this->got_irelative_->offset()));
1672 const section_size_type got_size =
1673 convert_to_section_size_type(this->got_plt_->data_size()
1674 + this->got_irelative_->data_size());
1675 unsigned char* const got_view = of->get_output_view(got_file_offset,
1676 got_size);
1677
1678 unsigned char* pov = oview;
1679
1680 // The base address of the .plt section.
1681 typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
1682 // The base address of the .got section.
1683 typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
1684 // The base address of the PLT portion of the .got section,
1685 // which is where the GOT pointer will point, and where the
1686 // three reserved GOT entries are located.
1687 typename elfcpp::Elf_types<size>::Elf_Addr got_address
1688 = this->got_plt_->address();
1689
1690 this->fill_first_plt_entry(pov, got_address, plt_address);
1691 pov += this->get_plt_entry_size();
1692
1693 // The first three entries in the GOT are reserved, and are written
1694 // by Output_data_got_plt_x86_64::do_write.
1695 unsigned char* got_pov = got_view + 24;
1696
1697 unsigned int plt_offset = this->get_plt_entry_size();
1698 unsigned int got_offset = 24;
1699 const unsigned int count = this->count_ + this->irelative_count_;
1700 for (unsigned int plt_index = 0;
1701 plt_index < count;
1702 ++plt_index,
1703 pov += this->get_plt_entry_size(),
1704 got_pov += 8,
1705 plt_offset += this->get_plt_entry_size(),
1706 got_offset += 8)
1707 {
1708 // Set and adjust the PLT entry itself.
1709 unsigned int lazy_offset = this->fill_plt_entry(pov,
1710 got_address, plt_address,
1711 got_offset, plt_offset,
1712 plt_index);
1713
1714 // Set the entry in the GOT.
1715 elfcpp::Swap<64, false>::writeval(got_pov,
1716 plt_address + plt_offset + lazy_offset);
1717 }
1718
1719 if (this->has_tlsdesc_entry())
1720 {
1721 // Set and adjust the reserved TLSDESC PLT entry.
1722 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1723 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
1724 tlsdesc_got_offset, plt_offset);
1725 pov += this->get_plt_entry_size();
1726 }
1727
1728 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1729 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1730
1731 of->write_output_view(offset, oview_size, oview);
1732 of->write_output_view(got_file_offset, got_size, got_view);
1733 }
1734
1735 // Create the PLT section.
1736
1737 template<int size>
1738 void
1739 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
1740 {
1741 if (this->plt_ == NULL)
1742 {
1743 // Create the GOT sections first.
1744 this->got_section(symtab, layout);
1745
1746 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
1747 this->got_irelative_);
1748
1749 // Add unwind information if requested.
1750 if (parameters->options().ld_generated_unwind_info())
1751 this->plt_->add_eh_frame(layout);
1752
1753 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1754 (elfcpp::SHF_ALLOC
1755 | elfcpp::SHF_EXECINSTR),
1756 this->plt_, ORDER_PLT, false);
1757
1758 // Make the sh_info field of .rela.plt point to .plt.
1759 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1760 rela_plt_os->set_info_section(this->plt_->output_section());
1761 }
1762 }
1763
1764 // Return the section for TLSDESC relocations.
1765
1766 template<int size>
1767 typename Target_x86_64<size>::Reloc_section*
1768 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
1769 {
1770 return this->plt_section()->rela_tlsdesc(layout);
1771 }
1772
1773 // Create a PLT entry for a global symbol.
1774
1775 template<int size>
1776 void
1777 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
1778 Symbol* gsym)
1779 {
1780 if (gsym->has_plt_offset())
1781 return;
1782
1783 if (this->plt_ == NULL)
1784 this->make_plt_section(symtab, layout);
1785
1786 this->plt_->add_entry(symtab, layout, gsym);
1787 }
1788
1789 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1790
1791 template<int size>
1792 void
1793 Target_x86_64<size>::make_local_ifunc_plt_entry(
1794 Symbol_table* symtab, Layout* layout,
1795 Sized_relobj_file<size, false>* relobj,
1796 unsigned int local_sym_index)
1797 {
1798 if (relobj->local_has_plt_offset(local_sym_index))
1799 return;
1800 if (this->plt_ == NULL)
1801 this->make_plt_section(symtab, layout);
1802 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1803 relobj,
1804 local_sym_index);
1805 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1806 }
1807
1808 // Return the number of entries in the PLT.
1809
1810 template<int size>
1811 unsigned int
1812 Target_x86_64<size>::plt_entry_count() const
1813 {
1814 if (this->plt_ == NULL)
1815 return 0;
1816 return this->plt_->entry_count();
1817 }
1818
1819 // Return the offset of the first non-reserved PLT entry.
1820
1821 template<int size>
1822 unsigned int
1823 Target_x86_64<size>::first_plt_entry_offset() const
1824 {
1825 return this->plt_->first_plt_entry_offset();
1826 }
1827
1828 // Return the size of each PLT entry.
1829
1830 template<int size>
1831 unsigned int
1832 Target_x86_64<size>::plt_entry_size() const
1833 {
1834 return this->plt_->get_plt_entry_size();
1835 }
1836
1837 // Create the GOT and PLT sections for an incremental update.
1838
1839 template<int size>
1840 Output_data_got_base*
1841 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
1842 Layout* layout,
1843 unsigned int got_count,
1844 unsigned int plt_count)
1845 {
1846 gold_assert(this->got_ == NULL);
1847
1848 this->got_ = new Output_data_got<64, false>(got_count * 8);
1849 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1850 (elfcpp::SHF_ALLOC
1851 | elfcpp::SHF_WRITE),
1852 this->got_, ORDER_RELRO_LAST,
1853 true);
1854
1855 // Add the three reserved entries.
1856 this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
1857 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1858 (elfcpp::SHF_ALLOC
1859 | elfcpp::SHF_WRITE),
1860 this->got_plt_, ORDER_NON_RELRO_FIRST,
1861 false);
1862
1863 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1864 this->global_offset_table_ =
1865 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1866 Symbol_table::PREDEFINED,
1867 this->got_plt_,
1868 0, 0, elfcpp::STT_OBJECT,
1869 elfcpp::STB_LOCAL,
1870 elfcpp::STV_HIDDEN, 0,
1871 false, false);
1872
1873 // If there are any TLSDESC relocations, they get GOT entries in
1874 // .got.plt after the jump slot entries.
1875 // FIXME: Get the count for TLSDESC entries.
1876 this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1877 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1878 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1879 this->got_tlsdesc_,
1880 ORDER_NON_RELRO_FIRST, false);
1881
1882 // If there are any IRELATIVE relocations, they get GOT entries in
1883 // .got.plt after the jump slot and TLSDESC entries.
1884 this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1885 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1886 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1887 this->got_irelative_,
1888 ORDER_NON_RELRO_FIRST, false);
1889
1890 // Create the PLT section.
1891 this->plt_ = this->make_data_plt(layout, this->got_,
1892 this->got_plt_,
1893 this->got_irelative_,
1894 plt_count);
1895
1896 // Add unwind information if requested.
1897 if (parameters->options().ld_generated_unwind_info())
1898 this->plt_->add_eh_frame(layout);
1899
1900 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1901 elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1902 this->plt_, ORDER_PLT, false);
1903
1904 // Make the sh_info field of .rela.plt point to .plt.
1905 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1906 rela_plt_os->set_info_section(this->plt_->output_section());
1907
1908 // Create the rela_dyn section.
1909 this->rela_dyn_section(layout);
1910
1911 return this->got_;
1912 }
1913
1914 // Reserve a GOT entry for a local symbol, and regenerate any
1915 // necessary dynamic relocations.
1916
1917 template<int size>
1918 void
1919 Target_x86_64<size>::reserve_local_got_entry(
1920 unsigned int got_index,
1921 Sized_relobj<size, false>* obj,
1922 unsigned int r_sym,
1923 unsigned int got_type)
1924 {
1925 unsigned int got_offset = got_index * 8;
1926 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1927
1928 this->got_->reserve_local(got_index, obj, r_sym, got_type);
1929 switch (got_type)
1930 {
1931 case GOT_TYPE_STANDARD:
1932 if (parameters->options().output_is_position_independent())
1933 rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1934 this->got_, got_offset, 0, false);
1935 break;
1936 case GOT_TYPE_TLS_OFFSET:
1937 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1938 this->got_, got_offset, 0);
1939 break;
1940 case GOT_TYPE_TLS_PAIR:
1941 this->got_->reserve_slot(got_index + 1);
1942 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1943 this->got_, got_offset, 0);
1944 break;
1945 case GOT_TYPE_TLS_DESC:
1946 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1947 // this->got_->reserve_slot(got_index + 1);
1948 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1949 // this->got_, got_offset, 0);
1950 break;
1951 default:
1952 gold_unreachable();
1953 }
1954 }
1955
1956 // Reserve a GOT entry for a global symbol, and regenerate any
1957 // necessary dynamic relocations.
1958
1959 template<int size>
1960 void
1961 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
1962 Symbol* gsym,
1963 unsigned int got_type)
1964 {
1965 unsigned int got_offset = got_index * 8;
1966 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1967
1968 this->got_->reserve_global(got_index, gsym, got_type);
1969 switch (got_type)
1970 {
1971 case GOT_TYPE_STANDARD:
1972 if (!gsym->final_value_is_known())
1973 {
1974 if (gsym->is_from_dynobj()
1975 || gsym->is_undefined()
1976 || gsym->is_preemptible()
1977 || gsym->type() == elfcpp::STT_GNU_IFUNC)
1978 rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1979 this->got_, got_offset, 0);
1980 else
1981 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1982 this->got_, got_offset, 0, false);
1983 }
1984 break;
1985 case GOT_TYPE_TLS_OFFSET:
1986 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1987 this->got_, got_offset, 0, false);
1988 break;
1989 case GOT_TYPE_TLS_PAIR:
1990 this->got_->reserve_slot(got_index + 1);
1991 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1992 this->got_, got_offset, 0, false);
1993 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1994 this->got_, got_offset + 8, 0, false);
1995 break;
1996 case GOT_TYPE_TLS_DESC:
1997 this->got_->reserve_slot(got_index + 1);
1998 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
1999 this->got_, got_offset, 0, false);
2000 break;
2001 default:
2002 gold_unreachable();
2003 }
2004 }
2005
2006 // Register an existing PLT entry for a global symbol.
2007
2008 template<int size>
2009 void
2010 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
2011 Layout* layout,
2012 unsigned int plt_index,
2013 Symbol* gsym)
2014 {
2015 gold_assert(this->plt_ != NULL);
2016 gold_assert(!gsym->has_plt_offset());
2017
2018 this->plt_->reserve_slot(plt_index);
2019
2020 gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
2021
2022 unsigned int got_offset = (plt_index + 3) * 8;
2023 this->plt_->add_relocation(symtab, layout, gsym, got_offset);
2024 }
2025
2026 // Force a COPY relocation for a given symbol.
2027
2028 template<int size>
2029 void
2030 Target_x86_64<size>::emit_copy_reloc(
2031 Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
2032 {
2033 this->copy_relocs_.emit_copy_reloc(symtab,
2034 symtab->get_sized_symbol<size>(sym),
2035 os,
2036 offset,
2037 this->rela_dyn_section(NULL));
2038 }
2039
2040 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2041
2042 template<int size>
2043 void
2044 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
2045 Layout* layout)
2046 {
2047 if (this->tls_base_symbol_defined_)
2048 return;
2049
2050 Output_segment* tls_segment = layout->tls_segment();
2051 if (tls_segment != NULL)
2052 {
2053 bool is_exec = parameters->options().output_is_executable();
2054 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
2055 Symbol_table::PREDEFINED,
2056 tls_segment, 0, 0,
2057 elfcpp::STT_TLS,
2058 elfcpp::STB_LOCAL,
2059 elfcpp::STV_HIDDEN, 0,
2060 (is_exec
2061 ? Symbol::SEGMENT_END
2062 : Symbol::SEGMENT_START),
2063 true);
2064 }
2065 this->tls_base_symbol_defined_ = true;
2066 }
2067
2068 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2069
2070 template<int size>
2071 void
2072 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
2073 Layout* layout)
2074 {
2075 if (this->plt_ == NULL)
2076 this->make_plt_section(symtab, layout);
2077
2078 if (!this->plt_->has_tlsdesc_entry())
2079 {
2080 // Allocate the TLSDESC_GOT entry.
2081 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2082 unsigned int got_offset = got->add_constant(0);
2083
2084 // Allocate the TLSDESC_PLT entry.
2085 this->plt_->reserve_tlsdesc_entry(got_offset);
2086 }
2087 }
2088
2089 // Create a GOT entry for the TLS module index.
2090
2091 template<int size>
2092 unsigned int
2093 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2094 Sized_relobj_file<size, false>* object)
2095 {
2096 if (this->got_mod_index_offset_ == -1U)
2097 {
2098 gold_assert(symtab != NULL && layout != NULL && object != NULL);
2099 Reloc_section* rela_dyn = this->rela_dyn_section(layout);
2100 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2101 unsigned int got_offset = got->add_constant(0);
2102 rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
2103 got_offset, 0);
2104 got->add_constant(0);
2105 this->got_mod_index_offset_ = got_offset;
2106 }
2107 return this->got_mod_index_offset_;
2108 }
2109
2110 // Optimize the TLS relocation type based on what we know about the
2111 // symbol. IS_FINAL is true if the final address of this symbol is
2112 // known at link time.
2113
2114 template<int size>
2115 tls::Tls_optimization
2116 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
2117 {
2118 // If we are generating a shared library, then we can't do anything
2119 // in the linker.
2120 if (parameters->options().shared())
2121 return tls::TLSOPT_NONE;
2122
2123 switch (r_type)
2124 {
2125 case elfcpp::R_X86_64_TLSGD:
2126 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2127 case elfcpp::R_X86_64_TLSDESC_CALL:
2128 // These are General-Dynamic which permits fully general TLS
2129 // access. Since we know that we are generating an executable,
2130 // we can convert this to Initial-Exec. If we also know that
2131 // this is a local symbol, we can further switch to Local-Exec.
2132 if (is_final)
2133 return tls::TLSOPT_TO_LE;
2134 return tls::TLSOPT_TO_IE;
2135
2136 case elfcpp::R_X86_64_TLSLD:
2137 // This is Local-Dynamic, which refers to a local symbol in the
2138 // dynamic TLS block. Since we know that we generating an
2139 // executable, we can switch to Local-Exec.
2140 return tls::TLSOPT_TO_LE;
2141
2142 case elfcpp::R_X86_64_DTPOFF32:
2143 case elfcpp::R_X86_64_DTPOFF64:
2144 // Another Local-Dynamic reloc.
2145 return tls::TLSOPT_TO_LE;
2146
2147 case elfcpp::R_X86_64_GOTTPOFF:
2148 // These are Initial-Exec relocs which get the thread offset
2149 // from the GOT. If we know that we are linking against the
2150 // local symbol, we can switch to Local-Exec, which links the
2151 // thread offset into the instruction.
2152 if (is_final)
2153 return tls::TLSOPT_TO_LE;
2154 return tls::TLSOPT_NONE;
2155
2156 case elfcpp::R_X86_64_TPOFF32:
2157 // When we already have Local-Exec, there is nothing further we
2158 // can do.
2159 return tls::TLSOPT_NONE;
2160
2161 default:
2162 gold_unreachable();
2163 }
2164 }
2165
2166 // Get the Reference_flags for a particular relocation.
2167
2168 template<int size>
2169 int
2170 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
2171 {
2172 switch (r_type)
2173 {
2174 case elfcpp::R_X86_64_NONE:
2175 case elfcpp::R_X86_64_GNU_VTINHERIT:
2176 case elfcpp::R_X86_64_GNU_VTENTRY:
2177 case elfcpp::R_X86_64_GOTPC32:
2178 case elfcpp::R_X86_64_GOTPC64:
2179 // No symbol reference.
2180 return 0;
2181
2182 case elfcpp::R_X86_64_64:
2183 case elfcpp::R_X86_64_32:
2184 case elfcpp::R_X86_64_32S:
2185 case elfcpp::R_X86_64_16:
2186 case elfcpp::R_X86_64_8:
2187 return Symbol::ABSOLUTE_REF;
2188
2189 case elfcpp::R_X86_64_PC64:
2190 case elfcpp::R_X86_64_PC32:
2191 case elfcpp::R_X86_64_PC32_BND:
2192 case elfcpp::R_X86_64_PC16:
2193 case elfcpp::R_X86_64_PC8:
2194 case elfcpp::R_X86_64_GOTOFF64:
2195 return Symbol::RELATIVE_REF;
2196
2197 case elfcpp::R_X86_64_PLT32:
2198 case elfcpp::R_X86_64_PLT32_BND:
2199 case elfcpp::R_X86_64_PLTOFF64:
2200 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
2201
2202 case elfcpp::R_X86_64_GOT64:
2203 case elfcpp::R_X86_64_GOT32:
2204 case elfcpp::R_X86_64_GOTPCREL64:
2205 case elfcpp::R_X86_64_GOTPCREL:
2206 case elfcpp::R_X86_64_GOTPCRELX:
2207 case elfcpp::R_X86_64_REX_GOTPCRELX:
2208 case elfcpp::R_X86_64_GOTPLT64:
2209 // Absolute in GOT.
2210 return Symbol::ABSOLUTE_REF;
2211
2212 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2213 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2214 case elfcpp::R_X86_64_TLSDESC_CALL:
2215 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2216 case elfcpp::R_X86_64_DTPOFF32:
2217 case elfcpp::R_X86_64_DTPOFF64:
2218 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2219 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2220 return Symbol::TLS_REF;
2221
2222 case elfcpp::R_X86_64_COPY:
2223 case elfcpp::R_X86_64_GLOB_DAT:
2224 case elfcpp::R_X86_64_JUMP_SLOT:
2225 case elfcpp::R_X86_64_RELATIVE:
2226 case elfcpp::R_X86_64_IRELATIVE:
2227 case elfcpp::R_X86_64_TPOFF64:
2228 case elfcpp::R_X86_64_DTPMOD64:
2229 case elfcpp::R_X86_64_TLSDESC:
2230 case elfcpp::R_X86_64_SIZE32:
2231 case elfcpp::R_X86_64_SIZE64:
2232 default:
2233 // Not expected. We will give an error later.
2234 return 0;
2235 }
2236 }
2237
2238 // Report an unsupported relocation against a local symbol.
2239
2240 template<int size>
2241 void
2242 Target_x86_64<size>::Scan::unsupported_reloc_local(
2243 Sized_relobj_file<size, false>* object,
2244 unsigned int r_type)
2245 {
2246 gold_error(_("%s: unsupported reloc %u against local symbol"),
2247 object->name().c_str(), r_type);
2248 }
2249
2250 // We are about to emit a dynamic relocation of type R_TYPE. If the
2251 // dynamic linker does not support it, issue an error. The GNU linker
2252 // only issues a non-PIC error for an allocated read-only section.
2253 // Here we know the section is allocated, but we don't know that it is
2254 // read-only. But we check for all the relocation types which the
2255 // glibc dynamic linker supports, so it seems appropriate to issue an
2256 // error even if the section is not read-only. If GSYM is not NULL,
2257 // it is the symbol the relocation is against; if it is NULL, the
2258 // relocation is against a local symbol.
2259
2260 template<int size>
2261 void
2262 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
2263 Symbol* gsym)
2264 {
2265 switch (r_type)
2266 {
2267 // These are the relocation types supported by glibc for x86_64
2268 // which should always work.
2269 case elfcpp::R_X86_64_RELATIVE:
2270 case elfcpp::R_X86_64_IRELATIVE:
2271 case elfcpp::R_X86_64_GLOB_DAT:
2272 case elfcpp::R_X86_64_JUMP_SLOT:
2273 case elfcpp::R_X86_64_DTPMOD64:
2274 case elfcpp::R_X86_64_DTPOFF64:
2275 case elfcpp::R_X86_64_TPOFF64:
2276 case elfcpp::R_X86_64_64:
2277 case elfcpp::R_X86_64_COPY:
2278 return;
2279
2280 // glibc supports these reloc types, but they can overflow.
2281 case elfcpp::R_X86_64_PC32:
2282 case elfcpp::R_X86_64_PC32_BND:
2283 // A PC relative reference is OK against a local symbol or if
2284 // the symbol is defined locally.
2285 if (gsym == NULL
2286 || (!gsym->is_from_dynobj()
2287 && !gsym->is_undefined()
2288 && !gsym->is_preemptible()))
2289 return;
2290 /* Fall through. */
2291 case elfcpp::R_X86_64_32:
2292 // R_X86_64_32 is OK for x32.
2293 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2294 return;
2295 if (this->issued_non_pic_error_)
2296 return;
2297 gold_assert(parameters->options().output_is_position_independent());
2298 if (gsym == NULL)
2299 object->error(_("requires dynamic R_X86_64_32 reloc which may "
2300 "overflow at runtime; recompile with -fPIC"));
2301 else
2302 {
2303 const char *r_name;
2304 switch (r_type)
2305 {
2306 case elfcpp::R_X86_64_32:
2307 r_name = "R_X86_64_32";
2308 break;
2309 case elfcpp::R_X86_64_PC32:
2310 r_name = "R_X86_64_PC32";
2311 break;
2312 case elfcpp::R_X86_64_PC32_BND:
2313 r_name = "R_X86_64_PC32_BND";
2314 break;
2315 default:
2316 gold_unreachable();
2317 break;
2318 }
2319 object->error(_("requires dynamic %s reloc against '%s' "
2320 "which may overflow at runtime; recompile "
2321 "with -fPIC"),
2322 r_name, gsym->name());
2323 }
2324 this->issued_non_pic_error_ = true;
2325 return;
2326
2327 default:
2328 // This prevents us from issuing more than one error per reloc
2329 // section. But we can still wind up issuing more than one
2330 // error per object file.
2331 if (this->issued_non_pic_error_)
2332 return;
2333 gold_assert(parameters->options().output_is_position_independent());
2334 object->error(_("requires unsupported dynamic reloc %u; "
2335 "recompile with -fPIC"),
2336 r_type);
2337 this->issued_non_pic_error_ = true;
2338 return;
2339
2340 case elfcpp::R_X86_64_NONE:
2341 gold_unreachable();
2342 }
2343 }
2344
2345 // Return whether we need to make a PLT entry for a relocation of the
2346 // given type against a STT_GNU_IFUNC symbol.
2347
2348 template<int size>
2349 bool
2350 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2351 Sized_relobj_file<size, false>* object,
2352 unsigned int r_type)
2353 {
2354 int flags = Scan::get_reference_flags(r_type);
2355 if (flags & Symbol::TLS_REF)
2356 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2357 object->name().c_str(), r_type);
2358 return flags != 0;
2359 }
2360
2361 // Scan a relocation for a local symbol.
2362
2363 template<int size>
2364 inline void
2365 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2366 Layout* layout,
2367 Target_x86_64<size>* target,
2368 Sized_relobj_file<size, false>* object,
2369 unsigned int data_shndx,
2370 Output_section* output_section,
2371 const elfcpp::Rela<size, false>& reloc,
2372 unsigned int r_type,
2373 const elfcpp::Sym<size, false>& lsym,
2374 bool is_discarded)
2375 {
2376 if (is_discarded)
2377 return;
2378
2379 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2380 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2381 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2382 {
2383 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2384 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2385 }
2386
2387 switch (r_type)
2388 {
2389 case elfcpp::R_X86_64_NONE:
2390 case elfcpp::R_X86_64_GNU_VTINHERIT:
2391 case elfcpp::R_X86_64_GNU_VTENTRY:
2392 break;
2393
2394 case elfcpp::R_X86_64_64:
2395 // If building a shared library (or a position-independent
2396 // executable), we need to create a dynamic relocation for this
2397 // location. The relocation applied at link time will apply the
2398 // link-time value, so we flag the location with an
2399 // R_X86_64_RELATIVE relocation so the dynamic loader can
2400 // relocate it easily.
2401 if (parameters->options().output_is_position_independent())
2402 {
2403 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2404 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2405 rela_dyn->add_local_relative(object, r_sym,
2406 (size == 32
2407 ? elfcpp::R_X86_64_RELATIVE64
2408 : elfcpp::R_X86_64_RELATIVE),
2409 output_section, data_shndx,
2410 reloc.get_r_offset(),
2411 reloc.get_r_addend(), is_ifunc);
2412 }
2413 break;
2414
2415 case elfcpp::R_X86_64_32:
2416 case elfcpp::R_X86_64_32S:
2417 case elfcpp::R_X86_64_16:
2418 case elfcpp::R_X86_64_8:
2419 // If building a shared library (or a position-independent
2420 // executable), we need to create a dynamic relocation for this
2421 // location. We can't use an R_X86_64_RELATIVE relocation
2422 // because that is always a 64-bit relocation.
2423 if (parameters->options().output_is_position_independent())
2424 {
2425 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2426 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2427 {
2428 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2429 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2430 rela_dyn->add_local_relative(object, r_sym,
2431 elfcpp::R_X86_64_RELATIVE,
2432 output_section, data_shndx,
2433 reloc.get_r_offset(),
2434 reloc.get_r_addend(), is_ifunc);
2435 break;
2436 }
2437
2438 this->check_non_pic(object, r_type, NULL);
2439
2440 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2441 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2442 if (lsym.get_st_type() != elfcpp::STT_SECTION)
2443 rela_dyn->add_local(object, r_sym, r_type, output_section,
2444 data_shndx, reloc.get_r_offset(),
2445 reloc.get_r_addend());
2446 else
2447 {
2448 gold_assert(lsym.get_st_value() == 0);
2449 unsigned int shndx = lsym.get_st_shndx();
2450 bool is_ordinary;
2451 shndx = object->adjust_sym_shndx(r_sym, shndx,
2452 &is_ordinary);
2453 if (!is_ordinary)
2454 object->error(_("section symbol %u has bad shndx %u"),
2455 r_sym, shndx);
2456 else
2457 rela_dyn->add_local_section(object, shndx,
2458 r_type, output_section,
2459 data_shndx, reloc.get_r_offset(),
2460 reloc.get_r_addend());
2461 }
2462 }
2463 break;
2464
2465 case elfcpp::R_X86_64_PC64:
2466 case elfcpp::R_X86_64_PC32:
2467 case elfcpp::R_X86_64_PC32_BND:
2468 case elfcpp::R_X86_64_PC16:
2469 case elfcpp::R_X86_64_PC8:
2470 break;
2471
2472 case elfcpp::R_X86_64_PLT32:
2473 case elfcpp::R_X86_64_PLT32_BND:
2474 // Since we know this is a local symbol, we can handle this as a
2475 // PC32 reloc.
2476 break;
2477
2478 case elfcpp::R_X86_64_GOTPC32:
2479 case elfcpp::R_X86_64_GOTOFF64:
2480 case elfcpp::R_X86_64_GOTPC64:
2481 case elfcpp::R_X86_64_PLTOFF64:
2482 // We need a GOT section.
2483 target->got_section(symtab, layout);
2484 // For PLTOFF64, we'd normally want a PLT section, but since we
2485 // know this is a local symbol, no PLT is needed.
2486 break;
2487
2488 case elfcpp::R_X86_64_GOT64:
2489 case elfcpp::R_X86_64_GOT32:
2490 case elfcpp::R_X86_64_GOTPCREL64:
2491 case elfcpp::R_X86_64_GOTPCREL:
2492 case elfcpp::R_X86_64_GOTPCRELX:
2493 case elfcpp::R_X86_64_REX_GOTPCRELX:
2494 case elfcpp::R_X86_64_GOTPLT64:
2495 {
2496 // The symbol requires a GOT section.
2497 Output_data_got<64, false>* got = target->got_section(symtab, layout);
2498
2499 // If the relocation symbol isn't IFUNC,
2500 // and is local, then we will convert
2501 // mov foo@GOTPCREL(%rip), %reg
2502 // to lea foo(%rip), %reg.
2503 // in Relocate::relocate.
2504 if ((r_type == elfcpp::R_X86_64_GOTPCREL
2505 || r_type == elfcpp::R_X86_64_GOTPCRELX
2506 || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
2507 && reloc.get_r_offset() >= 2
2508 && !is_ifunc)
2509 {
2510 section_size_type stype;
2511 const unsigned char* view = object->section_contents(data_shndx,
2512 &stype, true);
2513 if (view[reloc.get_r_offset() - 2] == 0x8b)
2514 break;
2515 }
2516
2517
2518 // The symbol requires a GOT entry.
2519 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2520
2521 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
2522 // lets function pointers compare correctly with shared
2523 // libraries. Otherwise we would need an IRELATIVE reloc.
2524 bool is_new;
2525 if (is_ifunc)
2526 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2527 else
2528 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2529 if (is_new)
2530 {
2531 // If we are generating a shared object, we need to add a
2532 // dynamic relocation for this symbol's GOT entry.
2533 if (parameters->options().output_is_position_independent())
2534 {
2535 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2536 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2537 if (r_type != elfcpp::R_X86_64_GOT32)
2538 {
2539 unsigned int got_offset =
2540 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2541 rela_dyn->add_local_relative(object, r_sym,
2542 elfcpp::R_X86_64_RELATIVE,
2543 got, got_offset, 0, is_ifunc);
2544 }
2545 else
2546 {
2547 this->check_non_pic(object, r_type, NULL);
2548
2549 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2550 rela_dyn->add_local(
2551 object, r_sym, r_type, got,
2552 object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2553 }
2554 }
2555 }
2556 // For GOTPLT64, we'd normally want a PLT section, but since
2557 // we know this is a local symbol, no PLT is needed.
2558 }
2559 break;
2560
2561 case elfcpp::R_X86_64_COPY:
2562 case elfcpp::R_X86_64_GLOB_DAT:
2563 case elfcpp::R_X86_64_JUMP_SLOT:
2564 case elfcpp::R_X86_64_RELATIVE:
2565 case elfcpp::R_X86_64_IRELATIVE:
2566 // These are outstanding tls relocs, which are unexpected when linking
2567 case elfcpp::R_X86_64_TPOFF64:
2568 case elfcpp::R_X86_64_DTPMOD64:
2569 case elfcpp::R_X86_64_TLSDESC:
2570 gold_error(_("%s: unexpected reloc %u in object file"),
2571 object->name().c_str(), r_type);
2572 break;
2573
2574 // These are initial tls relocs, which are expected when linking
2575 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2576 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2577 case elfcpp::R_X86_64_TLSDESC_CALL:
2578 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2579 case elfcpp::R_X86_64_DTPOFF32:
2580 case elfcpp::R_X86_64_DTPOFF64:
2581 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2582 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2583 {
2584 bool output_is_shared = parameters->options().shared();
2585 const tls::Tls_optimization optimized_type
2586 = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
2587 r_type);
2588 switch (r_type)
2589 {
2590 case elfcpp::R_X86_64_TLSGD: // General-dynamic
2591 if (optimized_type == tls::TLSOPT_NONE)
2592 {
2593 // Create a pair of GOT entries for the module index and
2594 // dtv-relative offset.
2595 Output_data_got<64, false>* got
2596 = target->got_section(symtab, layout);
2597 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2598 unsigned int shndx = lsym.get_st_shndx();
2599 bool is_ordinary;
2600 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2601 if (!is_ordinary)
2602 object->error(_("local symbol %u has bad shndx %u"),
2603 r_sym, shndx);
2604 else
2605 got->add_local_pair_with_rel(object, r_sym,
2606 shndx,
2607 GOT_TYPE_TLS_PAIR,
2608 target->rela_dyn_section(layout),
2609 elfcpp::R_X86_64_DTPMOD64);
2610 }
2611 else if (optimized_type != tls::TLSOPT_TO_LE)
2612 unsupported_reloc_local(object, r_type);
2613 break;
2614
2615 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2616 target->define_tls_base_symbol(symtab, layout);
2617 if (optimized_type == tls::TLSOPT_NONE)
2618 {
2619 // Create reserved PLT and GOT entries for the resolver.
2620 target->reserve_tlsdesc_entries(symtab, layout);
2621
2622 // Generate a double GOT entry with an
2623 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
2624 // is resolved lazily, so the GOT entry needs to be in
2625 // an area in .got.plt, not .got. Call got_section to
2626 // make sure the section has been created.
2627 target->got_section(symtab, layout);
2628 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2629 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2630 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2631 {
2632 unsigned int got_offset = got->add_constant(0);
2633 got->add_constant(0);
2634 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2635 got_offset);
2636 Reloc_section* rt = target->rela_tlsdesc_section(layout);
2637 // We store the arguments we need in a vector, and
2638 // use the index into the vector as the parameter
2639 // to pass to the target specific routines.
2640 uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2641 void* arg = reinterpret_cast<void*>(intarg);
2642 rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2643 got, got_offset, 0);
2644 }
2645 }
2646 else if (optimized_type != tls::TLSOPT_TO_LE)
2647 unsupported_reloc_local(object, r_type);
2648 break;
2649
2650 case elfcpp::R_X86_64_TLSDESC_CALL:
2651 break;
2652
2653 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2654 if (optimized_type == tls::TLSOPT_NONE)
2655 {
2656 // Create a GOT entry for the module index.
2657 target->got_mod_index_entry(symtab, layout, object);
2658 }
2659 else if (optimized_type != tls::TLSOPT_TO_LE)
2660 unsupported_reloc_local(object, r_type);
2661 break;
2662
2663 case elfcpp::R_X86_64_DTPOFF32:
2664 case elfcpp::R_X86_64_DTPOFF64:
2665 break;
2666
2667 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2668 layout->set_has_static_tls();
2669 if (optimized_type == tls::TLSOPT_NONE)
2670 {
2671 // Create a GOT entry for the tp-relative offset.
2672 Output_data_got<64, false>* got
2673 = target->got_section(symtab, layout);
2674 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2675 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
2676 target->rela_dyn_section(layout),
2677 elfcpp::R_X86_64_TPOFF64);
2678 }
2679 else if (optimized_type != tls::TLSOPT_TO_LE)
2680 unsupported_reloc_local(object, r_type);
2681 break;
2682
2683 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2684 layout->set_has_static_tls();
2685 if (output_is_shared)
2686 unsupported_reloc_local(object, r_type);
2687 break;
2688
2689 default:
2690 gold_unreachable();
2691 }
2692 }
2693 break;
2694
2695 case elfcpp::R_X86_64_SIZE32:
2696 case elfcpp::R_X86_64_SIZE64:
2697 default:
2698 gold_error(_("%s: unsupported reloc %u against local symbol"),
2699 object->name().c_str(), r_type);
2700 break;
2701 }
2702 }
2703
2704
2705 // Report an unsupported relocation against a global symbol.
2706
2707 template<int size>
2708 void
2709 Target_x86_64<size>::Scan::unsupported_reloc_global(
2710 Sized_relobj_file<size, false>* object,
2711 unsigned int r_type,
2712 Symbol* gsym)
2713 {
2714 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2715 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2716 }
2717
2718 // Returns true if this relocation type could be that of a function pointer.
2719 template<int size>
2720 inline bool
2721 Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
2722 {
2723 switch (r_type)
2724 {
2725 case elfcpp::R_X86_64_64:
2726 case elfcpp::R_X86_64_32:
2727 case elfcpp::R_X86_64_32S:
2728 case elfcpp::R_X86_64_16:
2729 case elfcpp::R_X86_64_8:
2730 case elfcpp::R_X86_64_GOT64:
2731 case elfcpp::R_X86_64_GOT32:
2732 case elfcpp::R_X86_64_GOTPCREL64:
2733 case elfcpp::R_X86_64_GOTPCREL:
2734 case elfcpp::R_X86_64_GOTPCRELX:
2735 case elfcpp::R_X86_64_REX_GOTPCRELX:
2736 case elfcpp::R_X86_64_GOTPLT64:
2737 {
2738 return true;
2739 }
2740 }
2741 return false;
2742 }
2743
2744 // For safe ICF, scan a relocation for a local symbol to check if it
2745 // corresponds to a function pointer being taken. In that case mark
2746 // the function whose pointer was taken as not foldable.
2747
2748 template<int size>
2749 inline bool
2750 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
2751 Symbol_table* ,
2752 Layout* ,
2753 Target_x86_64<size>* ,
2754 Sized_relobj_file<size, false>* ,
2755 unsigned int ,
2756 Output_section* ,
2757 const elfcpp::Rela<size, false>& ,
2758 unsigned int r_type,
2759 const elfcpp::Sym<size, false>&)
2760 {
2761 // When building a shared library, do not fold any local symbols as it is
2762 // not possible to distinguish pointer taken versus a call by looking at
2763 // the relocation types.
2764 return (parameters->options().shared()
2765 || possible_function_pointer_reloc(r_type));
2766 }
2767
2768 // For safe ICF, scan a relocation for a global symbol to check if it
2769 // corresponds to a function pointer being taken. In that case mark
2770 // the function whose pointer was taken as not foldable.
2771
2772 template<int size>
2773 inline bool
2774 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
2775 Symbol_table*,
2776 Layout* ,
2777 Target_x86_64<size>* ,
2778 Sized_relobj_file<size, false>* ,
2779 unsigned int ,
2780 Output_section* ,
2781 const elfcpp::Rela<size, false>& ,
2782 unsigned int r_type,
2783 Symbol* gsym)
2784 {
2785 // When building a shared library, do not fold symbols whose visibility
2786 // is hidden, internal or protected.
2787 return ((parameters->options().shared()
2788 && (gsym->visibility() == elfcpp::STV_INTERNAL
2789 || gsym->visibility() == elfcpp::STV_PROTECTED
2790 || gsym->visibility() == elfcpp::STV_HIDDEN))
2791 || possible_function_pointer_reloc(r_type));
2792 }
2793
2794 // Scan a relocation for a global symbol.
2795
2796 template<int size>
2797 inline void
2798 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
2799 Layout* layout,
2800 Target_x86_64<size>* target,
2801 Sized_relobj_file<size, false>* object,
2802 unsigned int data_shndx,
2803 Output_section* output_section,
2804 const elfcpp::Rela<size, false>& reloc,
2805 unsigned int r_type,
2806 Symbol* gsym)
2807 {
2808 // A STT_GNU_IFUNC symbol may require a PLT entry.
2809 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2810 && this->reloc_needs_plt_for_ifunc(object, r_type))
2811 target->make_plt_entry(symtab, layout, gsym);
2812
2813 switch (r_type)
2814 {
2815 case elfcpp::R_X86_64_NONE:
2816 case elfcpp::R_X86_64_GNU_VTINHERIT:
2817 case elfcpp::R_X86_64_GNU_VTENTRY:
2818 break;
2819
2820 case elfcpp::R_X86_64_64:
2821 case elfcpp::R_X86_64_32:
2822 case elfcpp::R_X86_64_32S:
2823 case elfcpp::R_X86_64_16:
2824 case elfcpp::R_X86_64_8:
2825 {
2826 // Make a PLT entry if necessary.
2827 if (gsym->needs_plt_entry())
2828 {
2829 target->make_plt_entry(symtab, layout, gsym);
2830 // Since this is not a PC-relative relocation, we may be
2831 // taking the address of a function. In that case we need to
2832 // set the entry in the dynamic symbol table to the address of
2833 // the PLT entry.
2834 if (gsym->is_from_dynobj() && !parameters->options().shared())
2835 gsym->set_needs_dynsym_value();
2836 }
2837 // Make a dynamic relocation if necessary.
2838 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2839 {
2840 if (!parameters->options().output_is_position_independent()
2841 && gsym->may_need_copy_reloc())
2842 {
2843 target->copy_reloc(symtab, layout, object,
2844 data_shndx, output_section, gsym, reloc);
2845 }
2846 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2847 || (size == 32 && r_type == elfcpp::R_X86_64_32))
2848 && gsym->type() == elfcpp::STT_GNU_IFUNC
2849 && gsym->can_use_relative_reloc(false)
2850 && !gsym->is_from_dynobj()
2851 && !gsym->is_undefined()
2852 && !gsym->is_preemptible())
2853 {
2854 // Use an IRELATIVE reloc for a locally defined
2855 // STT_GNU_IFUNC symbol. This makes a function
2856 // address in a PIE executable match the address in a
2857 // shared library that it links against.
2858 Reloc_section* rela_dyn =
2859 target->rela_irelative_section(layout);
2860 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2861 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2862 output_section, object,
2863 data_shndx,
2864 reloc.get_r_offset(),
2865 reloc.get_r_addend());
2866 }
2867 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2868 || (size == 32 && r_type == elfcpp::R_X86_64_32))
2869 && gsym->can_use_relative_reloc(false))
2870 {
2871 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2872 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2873 output_section, object,
2874 data_shndx,
2875 reloc.get_r_offset(),
2876 reloc.get_r_addend(), false);
2877 }
2878 else
2879 {
2880 this->check_non_pic(object, r_type, gsym);
2881 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2882 rela_dyn->add_global(gsym, r_type, output_section, object,
2883 data_shndx, reloc.get_r_offset(),
2884 reloc.get_r_addend());
2885 }
2886 }
2887 }
2888 break;
2889
2890 case elfcpp::R_X86_64_PC64:
2891 case elfcpp::R_X86_64_PC32:
2892 case elfcpp::R_X86_64_PC32_BND:
2893 case elfcpp::R_X86_64_PC16:
2894 case elfcpp::R_X86_64_PC8:
2895 {
2896 // Make a PLT entry if necessary.
2897 if (gsym->needs_plt_entry())
2898 target->make_plt_entry(symtab, layout, gsym);
2899 // Make a dynamic relocation if necessary.
2900 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2901 {
2902 if (parameters->options().output_is_executable()
2903 && gsym->may_need_copy_reloc())
2904 {
2905 target->copy_reloc(symtab, layout, object,
2906 data_shndx, output_section, gsym, reloc);
2907 }
2908 else
2909 {
2910 this->check_non_pic(object, r_type, gsym);
2911 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2912 rela_dyn->add_global(gsym, r_type, output_section, object,
2913 data_shndx, reloc.get_r_offset(),
2914 reloc.get_r_addend());
2915 }
2916 }
2917 }
2918 break;
2919
2920 case elfcpp::R_X86_64_GOT64:
2921 case elfcpp::R_X86_64_GOT32:
2922 case elfcpp::R_X86_64_GOTPCREL64:
2923 case elfcpp::R_X86_64_GOTPCREL:
2924 case elfcpp::R_X86_64_GOTPCRELX:
2925 case elfcpp::R_X86_64_REX_GOTPCRELX:
2926 case elfcpp::R_X86_64_GOTPLT64:
2927 {
2928 // The symbol requires a GOT entry.
2929 Output_data_got<64, false>* got = target->got_section(symtab, layout);
2930
2931 // If we convert this from
2932 // mov foo@GOTPCREL(%rip), %reg
2933 // to lea foo(%rip), %reg.
2934 // in Relocate::relocate, then there is nothing to do here.
2935 if ((r_type == elfcpp::R_X86_64_GOTPCREL
2936 || r_type == elfcpp::R_X86_64_GOTPCRELX
2937 || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
2938 && reloc.get_r_offset() >= 2
2939 && Target_x86_64<size>::can_convert_mov_to_lea(gsym))
2940 {
2941 section_size_type stype;
2942 const unsigned char* view = object->section_contents(data_shndx,
2943 &stype, true);
2944 if (view[reloc.get_r_offset() - 2] == 0x8b)
2945 break;
2946 }
2947
2948 if (gsym->final_value_is_known())
2949 {
2950 // For a STT_GNU_IFUNC symbol we want the PLT address.
2951 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2952 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2953 else
2954 got->add_global(gsym, GOT_TYPE_STANDARD);
2955 }
2956 else
2957 {
2958 // If this symbol is not fully resolved, we need to add a
2959 // dynamic relocation for it.
2960 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2961
2962 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2963 //
2964 // 1) The symbol may be defined in some other module.
2965 //
2966 // 2) We are building a shared library and this is a
2967 // protected symbol; using GLOB_DAT means that the dynamic
2968 // linker can use the address of the PLT in the main
2969 // executable when appropriate so that function address
2970 // comparisons work.
2971 //
2972 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2973 // code, again so that function address comparisons work.
2974 if (gsym->is_from_dynobj()
2975 || gsym->is_undefined()
2976 || gsym->is_preemptible()
2977 || (gsym->visibility() == elfcpp::STV_PROTECTED
2978 && parameters->options().shared())
2979 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2980 && parameters->options().output_is_position_independent()))
2981 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
2982 elfcpp::R_X86_64_GLOB_DAT);
2983 else
2984 {
2985 // For a STT_GNU_IFUNC symbol we want to write the PLT
2986 // offset into the GOT, so that function pointer
2987 // comparisons work correctly.
2988 bool is_new;
2989 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2990 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2991 else
2992 {
2993 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2994 // Tell the dynamic linker to use the PLT address
2995 // when resolving relocations.
2996 if (gsym->is_from_dynobj()
2997 && !parameters->options().shared())
2998 gsym->set_needs_dynsym_value();
2999 }
3000 if (is_new)
3001 {
3002 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
3003 rela_dyn->add_global_relative(gsym,
3004 elfcpp::R_X86_64_RELATIVE,
3005 got, got_off, 0, false);
3006 }
3007 }
3008 }
3009 }
3010 break;
3011
3012 case elfcpp::R_X86_64_PLT32:
3013 case elfcpp::R_X86_64_PLT32_BND:
3014 // If the symbol is fully resolved, this is just a PC32 reloc.
3015 // Otherwise we need a PLT entry.
3016 if (gsym->final_value_is_known())
3017 break;
3018 // If building a shared library, we can also skip the PLT entry
3019 // if the symbol is defined in the output file and is protected
3020 // or hidden.
3021 if (gsym->is_defined()
3022 && !gsym->is_from_dynobj()
3023 && !gsym->is_preemptible())
3024 break;
3025 target->make_plt_entry(symtab, layout, gsym);
3026 break;
3027
3028 case elfcpp::R_X86_64_GOTPC32:
3029 case elfcpp::R_X86_64_GOTOFF64:
3030 case elfcpp::R_X86_64_GOTPC64:
3031 case elfcpp::R_X86_64_PLTOFF64:
3032 // We need a GOT section.
3033 target->got_section(symtab, layout);
3034 // For PLTOFF64, we also need a PLT entry (but only if the
3035 // symbol is not fully resolved).
3036 if (r_type == elfcpp::R_X86_64_PLTOFF64
3037 && !gsym->final_value_is_known())
3038 target->make_plt_entry(symtab, layout, gsym);
3039 break;
3040
3041 case elfcpp::R_X86_64_COPY:
3042 case elfcpp::R_X86_64_GLOB_DAT:
3043 case elfcpp::R_X86_64_JUMP_SLOT:
3044 case elfcpp::R_X86_64_RELATIVE:
3045 case elfcpp::R_X86_64_IRELATIVE:
3046 // These are outstanding tls relocs, which are unexpected when linking
3047 case elfcpp::R_X86_64_TPOFF64:
3048 case elfcpp::R_X86_64_DTPMOD64:
3049 case elfcpp::R_X86_64_TLSDESC:
3050 gold_error(_("%s: unexpected reloc %u in object file"),
3051 object->name().c_str(), r_type);
3052 break;
3053
3054 // These are initial tls relocs, which are expected for global()
3055 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3056 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3057 case elfcpp::R_X86_64_TLSDESC_CALL:
3058 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3059 case elfcpp::R_X86_64_DTPOFF32:
3060 case elfcpp::R_X86_64_DTPOFF64:
3061 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3062 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3063 {
3064 // For the Initial-Exec model, we can treat undef symbols as final
3065 // when building an executable.
3066 const bool is_final = (gsym->final_value_is_known() ||
3067 (r_type == elfcpp::R_X86_64_GOTTPOFF &&
3068 gsym->is_undefined() &&
3069 parameters->options().output_is_executable()));
3070 const tls::Tls_optimization optimized_type
3071 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3072 switch (r_type)
3073 {
3074 case elfcpp::R_X86_64_TLSGD: // General-dynamic
3075 if (optimized_type == tls::TLSOPT_NONE)
3076 {
3077 // Create a pair of GOT entries for the module index and
3078 // dtv-relative offset.
3079 Output_data_got<64, false>* got
3080 = target->got_section(symtab, layout);
3081 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
3082 target->rela_dyn_section(layout),
3083 elfcpp::R_X86_64_DTPMOD64,
3084 elfcpp::R_X86_64_DTPOFF64);
3085 }
3086 else if (optimized_type == tls::TLSOPT_TO_IE)
3087 {
3088 // Create a GOT entry for the tp-relative offset.
3089 Output_data_got<64, false>* got
3090 = target->got_section(symtab, layout);
3091 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3092 target->rela_dyn_section(layout),
3093 elfcpp::R_X86_64_TPOFF64);
3094 }
3095 else if (optimized_type != tls::TLSOPT_TO_LE)
3096 unsupported_reloc_global(object, r_type, gsym);
3097 break;
3098
3099 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3100 target->define_tls_base_symbol(symtab, layout);
3101 if (optimized_type == tls::TLSOPT_NONE)
3102 {
3103 // Create reserved PLT and GOT entries for the resolver.
3104 target->reserve_tlsdesc_entries(symtab, layout);
3105
3106 // Create a double GOT entry with an R_X86_64_TLSDESC
3107 // reloc. The R_X86_64_TLSDESC reloc is resolved
3108 // lazily, so the GOT entry needs to be in an area in
3109 // .got.plt, not .got. Call got_section to make sure
3110 // the section has been created.
3111 target->got_section(symtab, layout);
3112 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3113 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3114 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
3115 elfcpp::R_X86_64_TLSDESC, 0);
3116 }
3117 else if (optimized_type == tls::TLSOPT_TO_IE)
3118 {
3119 // Create a GOT entry for the tp-relative offset.
3120 Output_data_got<64, false>* got
3121 = target->got_section(symtab, layout);
3122 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3123 target->rela_dyn_section(layout),
3124 elfcpp::R_X86_64_TPOFF64);
3125 }
3126 else if (optimized_type != tls::TLSOPT_TO_LE)
3127 unsupported_reloc_global(object, r_type, gsym);
3128 break;
3129
3130 case elfcpp::R_X86_64_TLSDESC_CALL:
3131 break;
3132
3133 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3134 if (optimized_type == tls::TLSOPT_NONE)
3135 {
3136 // Create a GOT entry for the module index.
3137 target->got_mod_index_entry(symtab, layout, object);
3138 }
3139 else if (optimized_type != tls::TLSOPT_TO_LE)
3140 unsupported_reloc_global(object, r_type, gsym);
3141 break;
3142
3143 case elfcpp::R_X86_64_DTPOFF32:
3144 case elfcpp::R_X86_64_DTPOFF64:
3145 break;
3146
3147 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3148 layout->set_has_static_tls();
3149 if (optimized_type == tls::TLSOPT_NONE)
3150 {
3151 // Create a GOT entry for the tp-relative offset.
3152 Output_data_got<64, false>* got
3153 = target->got_section(symtab, layout);
3154 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3155 target->rela_dyn_section(layout),
3156 elfcpp::R_X86_64_TPOFF64);
3157 }
3158 else if (optimized_type != tls::TLSOPT_TO_LE)
3159 unsupported_reloc_global(object, r_type, gsym);
3160 break;
3161
3162 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3163 layout->set_has_static_tls();
3164 if (parameters->options().shared())
3165 unsupported_reloc_global(object, r_type, gsym);
3166 break;
3167
3168 default:
3169 gold_unreachable();
3170 }
3171 }
3172 break;
3173
3174 case elfcpp::R_X86_64_SIZE32:
3175 case elfcpp::R_X86_64_SIZE64:
3176 default:
3177 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3178 object->name().c_str(), r_type,
3179 gsym->demangled_name().c_str());
3180 break;
3181 }
3182 }
3183
3184 template<int size>
3185 void
3186 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
3187 Layout* layout,
3188 Sized_relobj_file<size, false>* object,
3189 unsigned int data_shndx,
3190 unsigned int sh_type,
3191 const unsigned char* prelocs,
3192 size_t reloc_count,
3193 Output_section* output_section,
3194 bool needs_special_offset_handling,
3195 size_t local_symbol_count,
3196 const unsigned char* plocal_symbols)
3197 {
3198 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3199 Classify_reloc;
3200
3201 if (sh_type == elfcpp::SHT_REL)
3202 {
3203 return;
3204 }
3205
3206 gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
3207 Classify_reloc>(
3208 symtab,
3209 layout,
3210 this,
3211 object,
3212 data_shndx,
3213 prelocs,
3214 reloc_count,
3215 output_section,
3216 needs_special_offset_handling,
3217 local_symbol_count,
3218 plocal_symbols);
3219
3220 }
3221 // Scan relocations for a section.
3222
3223 template<int size>
3224 void
3225 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
3226 Layout* layout,
3227 Sized_relobj_file<size, false>* object,
3228 unsigned int data_shndx,
3229 unsigned int sh_type,
3230 const unsigned char* prelocs,
3231 size_t reloc_count,
3232 Output_section* output_section,
3233 bool needs_special_offset_handling,
3234 size_t local_symbol_count,
3235 const unsigned char* plocal_symbols)
3236 {
3237 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3238 Classify_reloc;
3239
3240 if (sh_type == elfcpp::SHT_REL)
3241 {
3242 gold_error(_("%s: unsupported REL reloc section"),
3243 object->name().c_str());
3244 return;
3245 }
3246
3247 gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
3248 symtab,
3249 layout,
3250 this,
3251 object,
3252 data_shndx,
3253 prelocs,
3254 reloc_count,
3255 output_section,
3256 needs_special_offset_handling,
3257 local_symbol_count,
3258 plocal_symbols);
3259 }
3260
3261 // Finalize the sections.
3262
3263 template<int size>
3264 void
3265 Target_x86_64<size>::do_finalize_sections(
3266 Layout* layout,
3267 const Input_objects*,
3268 Symbol_table* symtab)
3269 {
3270 const Reloc_section* rel_plt = (this->plt_ == NULL
3271 ? NULL
3272 : this->plt_->rela_plt());
3273 layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
3274 this->rela_dyn_, true, false);
3275
3276 // Fill in some more dynamic tags.
3277 Output_data_dynamic* const odyn = layout->dynamic_data();
3278 if (odyn != NULL)
3279 {
3280 if (this->plt_ != NULL
3281 && this->plt_->output_section() != NULL
3282 && this->plt_->has_tlsdesc_entry())
3283 {
3284 unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
3285 unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
3286 this->got_->finalize_data_size();
3287 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
3288 this->plt_, plt_offset);
3289 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
3290 this->got_, got_offset);
3291 }
3292 }
3293
3294 // Emit any relocs we saved in an attempt to avoid generating COPY
3295 // relocs.
3296 if (this->copy_relocs_.any_saved_relocs())
3297 this->copy_relocs_.emit(this->rela_dyn_section(layout));
3298
3299 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3300 // the .got.plt section.
3301 Symbol* sym = this->global_offset_table_;
3302 if (sym != NULL)
3303 {
3304 uint64_t data_size = this->got_plt_->current_data_size();
3305 symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
3306 }
3307
3308 if (parameters->doing_static_link()
3309 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
3310 {
3311 // If linking statically, make sure that the __rela_iplt symbols
3312 // were defined if necessary, even if we didn't create a PLT.
3313 static const Define_symbol_in_segment syms[] =
3314 {
3315 {
3316 "__rela_iplt_start", // name
3317 elfcpp::PT_LOAD, // segment_type
3318 elfcpp::PF_W, // segment_flags_set
3319 elfcpp::PF(0), // segment_flags_clear
3320 0, // value
3321 0, // size
3322 elfcpp::STT_NOTYPE, // type
3323 elfcpp::STB_GLOBAL, // binding
3324 elfcpp::STV_HIDDEN, // visibility
3325 0, // nonvis
3326 Symbol::SEGMENT_START, // offset_from_base
3327 true // only_if_ref
3328 },
3329 {
3330 "__rela_iplt_end", // name
3331 elfcpp::PT_LOAD, // segment_type
3332 elfcpp::PF_W, // segment_flags_set
3333 elfcpp::PF(0), // segment_flags_clear
3334 0, // value
3335 0, // size
3336 elfcpp::STT_NOTYPE, // type
3337 elfcpp::STB_GLOBAL, // binding
3338 elfcpp::STV_HIDDEN, // visibility
3339 0, // nonvis
3340 Symbol::SEGMENT_START, // offset_from_base
3341 true // only_if_ref
3342 }
3343 };
3344
3345 symtab->define_symbols(layout, 2, syms,
3346 layout->script_options()->saw_sections_clause());
3347 }
3348 }
3349
3350 // For x32, we need to handle PC-relative relocations using full 64-bit
3351 // arithmetic, so that we can detect relocation overflows properly.
3352 // This class overrides the pcrela32_check methods from the defaults in
3353 // Relocate_functions in reloc.h.
3354
3355 template<int size>
3356 class X86_64_relocate_functions : public Relocate_functions<size, false>
3357 {
3358 public:
3359 typedef Relocate_functions<size, false> Base;
3360
3361 // Do a simple PC relative relocation with the addend in the
3362 // relocation.
3363 static inline typename Base::Reloc_status
3364 pcrela32_check(unsigned char* view,
3365 typename elfcpp::Elf_types<64>::Elf_Addr value,
3366 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
3367 typename elfcpp::Elf_types<64>::Elf_Addr address)
3368 {
3369 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
3370 Valtype* wv = reinterpret_cast<Valtype*>(view);
3371 value = value + addend - address;
3372 elfcpp::Swap<32, false>::writeval(wv, value);
3373 return (Bits<32>::has_overflow(value)
3374 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
3375 }
3376
3377 // Do a simple PC relative relocation with a Symbol_value with the
3378 // addend in the relocation.
3379 static inline typename Base::Reloc_status
3380 pcrela32_check(unsigned char* view,
3381 const Sized_relobj_file<size, false>* object,
3382 const Symbol_value<size>* psymval,
3383 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
3384 typename elfcpp::Elf_types<64>::Elf_Addr address)
3385 {
3386 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
3387 Valtype* wv = reinterpret_cast<Valtype*>(view);
3388 typename elfcpp::Elf_types<64>::Elf_Addr value;
3389 if (addend >= 0)
3390 value = psymval->value(object, addend);
3391 else
3392 {
3393 // For negative addends, get the symbol value without
3394 // the addend, then add the addend using 64-bit arithmetic.
3395 value = psymval->value(object, 0);
3396 value += addend;
3397 }
3398 value -= address;
3399 elfcpp::Swap<32, false>::writeval(wv, value);
3400 return (Bits<32>::has_overflow(value)
3401 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
3402 }
3403 };
3404
3405 // Perform a relocation.
3406
3407 template<int size>
3408 inline bool
3409 Target_x86_64<size>::Relocate::relocate(
3410 const Relocate_info<size, false>* relinfo,
3411 unsigned int,
3412 Target_x86_64<size>* target,
3413 Output_section*,
3414 size_t relnum,
3415 const unsigned char* preloc,
3416 const Sized_symbol<size>* gsym,
3417 const Symbol_value<size>* psymval,
3418 unsigned char* view,
3419 typename elfcpp::Elf_types<size>::Elf_Addr address,
3420 section_size_type view_size)
3421 {
3422 typedef X86_64_relocate_functions<size> Reloc_funcs;
3423 const elfcpp::Rela<size, false> rela(preloc);
3424 unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
3425
3426 if (this->skip_call_tls_get_addr_)
3427 {
3428 if ((r_type != elfcpp::R_X86_64_PLT32
3429 && r_type != elfcpp::R_X86_64_PLT32_BND
3430 && r_type != elfcpp::R_X86_64_PC32_BND
3431 && r_type != elfcpp::R_X86_64_PC32)
3432 || gsym == NULL
3433 || strcmp(gsym->name(), "__tls_get_addr") != 0)
3434 {
3435 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3436 _("missing expected TLS relocation"));
3437 }
3438 else
3439 {
3440 this->skip_call_tls_get_addr_ = false;
3441 return false;
3442 }
3443 }
3444
3445 if (view == NULL)
3446 return true;
3447
3448 const Sized_relobj_file<size, false>* object = relinfo->object;
3449
3450 // Pick the value to use for symbols defined in the PLT.
3451 Symbol_value<size> symval;
3452 if (gsym != NULL
3453 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
3454 {
3455 symval.set_output_value(target->plt_address_for_global(gsym));
3456 psymval = &symval;
3457 }
3458 else if (gsym == NULL && psymval->is_ifunc_symbol())
3459 {
3460 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3461 if (object->local_has_plt_offset(r_sym))
3462 {
3463 symval.set_output_value(target->plt_address_for_local(object, r_sym));
3464 psymval = &symval;
3465 }
3466 }
3467
3468 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3469
3470 // Get the GOT offset if needed.
3471 // The GOT pointer points to the end of the GOT section.
3472 // We need to subtract the size of the GOT section to get
3473 // the actual offset to use in the relocation.
3474 bool have_got_offset = false;
3475 // Since the actual offset is always negative, we use signed int to
3476 // support 64-bit GOT relocations.
3477 int got_offset = 0;
3478 switch (r_type)
3479 {
3480 case elfcpp::R_X86_64_GOT32:
3481 case elfcpp::R_X86_64_GOT64:
3482 case elfcpp::R_X86_64_GOTPLT64:
3483 case elfcpp::R_X86_64_GOTPCREL64:
3484 if (gsym != NULL)
3485 {
3486 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3487 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3488 }
3489 else
3490 {
3491 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3492 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3493 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3494 - target->got_size());
3495 }
3496 have_got_offset = true;
3497 break;
3498
3499 default:
3500 break;
3501 }
3502
3503 typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
3504
3505 switch (r_type)
3506 {
3507 case elfcpp::R_X86_64_NONE:
3508 case elfcpp::R_X86_64_GNU_VTINHERIT:
3509 case elfcpp::R_X86_64_GNU_VTENTRY:
3510 break;
3511
3512 case elfcpp::R_X86_64_64:
3513 Reloc_funcs::rela64(view, object, psymval, addend);
3514 break;
3515
3516 case elfcpp::R_X86_64_PC64:
3517 Reloc_funcs::pcrela64(view, object, psymval, addend,
3518 address);
3519 break;
3520
3521 case elfcpp::R_X86_64_32:
3522 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
3523 Reloc_funcs::CHECK_UNSIGNED);
3524 break;
3525
3526 case elfcpp::R_X86_64_32S:
3527 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
3528 Reloc_funcs::CHECK_SIGNED);
3529 break;
3530
3531 case elfcpp::R_X86_64_PC32:
3532 case elfcpp::R_X86_64_PC32_BND:
3533 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
3534 address);
3535 break;
3536
3537 case elfcpp::R_X86_64_16:
3538 Reloc_funcs::rela16(view, object, psymval, addend);
3539 break;
3540
3541 case elfcpp::R_X86_64_PC16:
3542 Reloc_funcs::pcrela16(view, object, psymval, addend, address);
3543 break;
3544
3545 case elfcpp::R_X86_64_8:
3546 Reloc_funcs::rela8(view, object, psymval, addend);
3547 break;
3548
3549 case elfcpp::R_X86_64_PC8:
3550 Reloc_funcs::pcrela8(view, object, psymval, addend, address);
3551 break;
3552
3553 case elfcpp::R_X86_64_PLT32:
3554 case elfcpp::R_X86_64_PLT32_BND:
3555 gold_assert(gsym == NULL
3556 || gsym->has_plt_offset()
3557 || gsym->final_value_is_known()
3558 || (gsym->is_defined()
3559 && !gsym->is_from_dynobj()
3560 && !gsym->is_preemptible()));
3561 // Note: while this code looks the same as for R_X86_64_PC32, it
3562 // behaves differently because psymval was set to point to
3563 // the PLT entry, rather than the symbol, in Scan::global().
3564 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
3565 address);
3566 break;
3567
3568 case elfcpp::R_X86_64_PLTOFF64:
3569 {
3570 gold_assert(gsym);
3571 gold_assert(gsym->has_plt_offset()
3572 || gsym->final_value_is_known());
3573 typename elfcpp::Elf_types<size>::Elf_Addr got_address;
3574 // This is the address of GLOBAL_OFFSET_TABLE.
3575 got_address = target->got_plt_section()->address();
3576 Reloc_funcs::rela64(view, object, psymval, addend - got_address);
3577 }
3578 break;
3579
3580 case elfcpp::R_X86_64_GOT32:
3581 gold_assert(have_got_offset);
3582 Reloc_funcs::rela32(view, got_offset, addend);
3583 break;
3584
3585 case elfcpp::R_X86_64_GOTPC32:
3586 {
3587 gold_assert(gsym);
3588 typename elfcpp::Elf_types<size>::Elf_Addr value;
3589 value = target->got_plt_section()->address();
3590 Reloc_funcs::pcrela32_check(view, value, addend, address);
3591 }
3592 break;
3593
3594 case elfcpp::R_X86_64_GOT64:
3595 case elfcpp::R_X86_64_GOTPLT64:
3596 // R_X86_64_GOTPLT64 is obsolete and treated the the same as
3597 // GOT64.
3598 gold_assert(have_got_offset);
3599 Reloc_funcs::rela64(view, got_offset, addend);
3600 break;
3601
3602 case elfcpp::R_X86_64_GOTPC64:
3603 {
3604 gold_assert(gsym);
3605 typename elfcpp::Elf_types<size>::Elf_Addr value;
3606 value = target->got_plt_section()->address();
3607 Reloc_funcs::pcrela64(view, value, addend, address);
3608 }
3609 break;
3610
3611 case elfcpp::R_X86_64_GOTOFF64:
3612 {
3613 typename elfcpp::Elf_types<size>::Elf_Addr value;
3614 value = (psymval->value(object, 0)
3615 - target->got_plt_section()->address());
3616 Reloc_funcs::rela64(view, value, addend);
3617 }
3618 break;
3619
3620 case elfcpp::R_X86_64_GOTPCREL:
3621 case elfcpp::R_X86_64_GOTPCRELX:
3622 case elfcpp::R_X86_64_REX_GOTPCRELX:
3623 {
3624 // Convert
3625 // mov foo@GOTPCREL(%rip), %reg
3626 // to lea foo(%rip), %reg.
3627 // if possible.
3628 if (rela.get_r_offset() >= 2
3629 && view[-2] == 0x8b
3630 && ((gsym == NULL && !psymval->is_ifunc_symbol())
3631 || (gsym != NULL
3632 && Target_x86_64<size>::can_convert_mov_to_lea(gsym))))
3633 {
3634 view[-2] = 0x8d;
3635 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
3636 }
3637 else
3638 {
3639 if (gsym != NULL)
3640 {
3641 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3642 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3643 }
3644 else
3645 {
3646 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3647 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3648 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3649 - target->got_size());
3650 }
3651 typename elfcpp::Elf_types<size>::Elf_Addr value;
3652 value = target->got_plt_section()->address() + got_offset;
3653 Reloc_funcs::pcrela32_check(view, value, addend, address);
3654 }
3655 }
3656 break;
3657
3658 case elfcpp::R_X86_64_GOTPCREL64:
3659 {
3660 gold_assert(have_got_offset);
3661 typename elfcpp::Elf_types<size>::Elf_Addr value;
3662 value = target->got_plt_section()->address() + got_offset;
3663 Reloc_funcs::pcrela64(view, value, addend, address);
3664 }
3665 break;
3666
3667 case elfcpp::R_X86_64_COPY:
3668 case elfcpp::R_X86_64_GLOB_DAT:
3669 case elfcpp::R_X86_64_JUMP_SLOT:
3670 case elfcpp::R_X86_64_RELATIVE:
3671 case elfcpp::R_X86_64_IRELATIVE:
3672 // These are outstanding tls relocs, which are unexpected when linking
3673 case elfcpp::R_X86_64_TPOFF64:
3674 case elfcpp::R_X86_64_DTPMOD64:
3675 case elfcpp::R_X86_64_TLSDESC:
3676 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3677 _("unexpected reloc %u in object file"),
3678 r_type);
3679 break;
3680
3681 // These are initial tls relocs, which are expected when linking
3682 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3683 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3684 case elfcpp::R_X86_64_TLSDESC_CALL:
3685 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3686 case elfcpp::R_X86_64_DTPOFF32:
3687 case elfcpp::R_X86_64_DTPOFF64:
3688 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3689 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3690 this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3691 view, address, view_size);
3692 break;
3693
3694 case elfcpp::R_X86_64_SIZE32:
3695 case elfcpp::R_X86_64_SIZE64:
3696 default:
3697 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3698 _("unsupported reloc %u"),
3699 r_type);
3700 break;
3701 }
3702
3703 if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
3704 {
3705 if (gsym == NULL)
3706 {
3707 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3708 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3709 _("relocation overflow: "
3710 "reference to local symbol %u in %s"),
3711 r_sym, object->name().c_str());
3712 }
3713 else if (gsym->is_defined() && gsym->source() == Symbol::FROM_OBJECT)
3714 {
3715 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3716 _("relocation overflow: "
3717 "reference to '%s' defined in %s"),
3718 gsym->name(),
3719 gsym->object()->name().c_str());
3720 }
3721 else
3722 {
3723 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3724 _("relocation overflow: reference to '%s'"),
3725 gsym->name());
3726 }
3727 }
3728
3729 return true;
3730 }
3731
3732 // Perform a TLS relocation.
3733
3734 template<int size>
3735 inline void
3736 Target_x86_64<size>::Relocate::relocate_tls(
3737 const Relocate_info<size, false>* relinfo,
3738 Target_x86_64<size>* target,
3739 size_t relnum,
3740 const elfcpp::Rela<size, false>& rela,
3741 unsigned int r_type,
3742 const Sized_symbol<size>* gsym,
3743 const Symbol_value<size>* psymval,
3744 unsigned char* view,
3745 typename elfcpp::Elf_types<size>::Elf_Addr address,
3746 section_size_type view_size)
3747 {
3748 Output_segment* tls_segment = relinfo->layout->tls_segment();
3749
3750 const Sized_relobj_file<size, false>* object = relinfo->object;
3751 const elfcpp::Elf_Xword addend = rela.get_r_addend();
3752 elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
3753 bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3754
3755 typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
3756
3757 const bool is_final = (gsym == NULL
3758 ? !parameters->options().shared()
3759 : gsym->final_value_is_known());
3760 tls::Tls_optimization optimized_type
3761 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3762 switch (r_type)
3763 {
3764 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3765 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3766 {
3767 // If this code sequence is used in a non-executable section,
3768 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3769 // on the assumption that it's being used by itself in a debug
3770 // section. Therefore, in the unlikely event that the code
3771 // sequence appears in a non-executable section, we simply
3772 // leave it unoptimized.
3773 optimized_type = tls::TLSOPT_NONE;
3774 }
3775 if (optimized_type == tls::TLSOPT_TO_LE)
3776 {
3777 if (tls_segment == NULL)
3778 {
3779 gold_assert(parameters->errors()->error_count() > 0
3780 || issue_undefined_symbol_error(gsym));
3781 return;
3782 }
3783 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3784 rela, r_type, value, view,
3785 view_size);
3786 break;
3787 }
3788 else
3789 {
3790 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3791 ? GOT_TYPE_TLS_OFFSET
3792 : GOT_TYPE_TLS_PAIR);
3793 unsigned int got_offset;
3794 if (gsym != NULL)
3795 {
3796 gold_assert(gsym->has_got_offset(got_type));
3797 got_offset = gsym->got_offset(got_type) - target->got_size();
3798 }
3799 else
3800 {
3801 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3802 gold_assert(object->local_has_got_offset(r_sym, got_type));
3803 got_offset = (object->local_got_offset(r_sym, got_type)
3804 - target->got_size());
3805 }
3806 if (optimized_type == tls::TLSOPT_TO_IE)
3807 {
3808 value = target->got_plt_section()->address() + got_offset;
3809 this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
3810 value, view, address, view_size);
3811 break;
3812 }
3813 else if (optimized_type == tls::TLSOPT_NONE)
3814 {
3815 // Relocate the field with the offset of the pair of GOT
3816 // entries.
3817 value = target->got_plt_section()->address() + got_offset;
3818 Relocate_functions<size, false>::pcrela32(view, value, addend,
3819 address);
3820 break;
3821 }
3822 }
3823 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3824 _("unsupported reloc %u"), r_type);
3825 break;
3826
3827 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3828 case elfcpp::R_X86_64_TLSDESC_CALL:
3829 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3830 {
3831 // See above comment for R_X86_64_TLSGD.
3832 optimized_type = tls::TLSOPT_NONE;
3833 }
3834 if (optimized_type == tls::TLSOPT_TO_LE)
3835 {
3836 if (tls_segment == NULL)
3837 {
3838 gold_assert(parameters->errors()->error_count() > 0
3839 || issue_undefined_symbol_error(gsym));
3840 return;
3841 }
3842 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3843 rela, r_type, value, view,
3844 view_size);
3845 break;
3846 }
3847 else
3848 {
3849 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3850 ? GOT_TYPE_TLS_OFFSET
3851 : GOT_TYPE_TLS_DESC);
3852 unsigned int got_offset = 0;
3853 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3854 && optimized_type == tls::TLSOPT_NONE)
3855 {
3856 // We created GOT entries in the .got.tlsdesc portion of
3857 // the .got.plt section, but the offset stored in the
3858 // symbol is the offset within .got.tlsdesc.
3859 got_offset = (target->got_size()
3860 + target->got_plt_section()->data_size());
3861 }
3862 if (gsym != NULL)
3863 {
3864 gold_assert(gsym->has_got_offset(got_type));
3865 got_offset += gsym->got_offset(got_type) - target->got_size();
3866 }
3867 else
3868 {
3869 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3870 gold_assert(object->local_has_got_offset(r_sym, got_type));
3871 got_offset += (object->local_got_offset(r_sym, got_type)
3872 - target->got_size());
3873 }
3874 if (optimized_type == tls::TLSOPT_TO_IE)
3875 {
3876 value = target->got_plt_section()->address() + got_offset;
3877 this->tls_desc_gd_to_ie(relinfo, relnum,
3878 rela, r_type, value, view, address,
3879 view_size);
3880 break;
3881 }
3882 else if (optimized_type == tls::TLSOPT_NONE)
3883 {
3884 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3885 {
3886 // Relocate the field with the offset of the pair of GOT
3887 // entries.
3888 value = target->got_plt_section()->address() + got_offset;
3889 Relocate_functions<size, false>::pcrela32(view, value, addend,
3890 address);
3891 }
3892 break;
3893 }
3894 }
3895 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3896 _("unsupported reloc %u"), r_type);
3897 break;
3898
3899 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3900 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3901 {
3902 // See above comment for R_X86_64_TLSGD.
3903 optimized_type = tls::TLSOPT_NONE;
3904 }
3905 if (optimized_type == tls::TLSOPT_TO_LE)
3906 {
3907 if (tls_segment == NULL)
3908 {
3909 gold_assert(parameters->errors()->error_count() > 0
3910 || issue_undefined_symbol_error(gsym));
3911 return;
3912 }
3913 this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3914 value, view, view_size);
3915 break;
3916 }
3917 else if (optimized_type == tls::TLSOPT_NONE)
3918 {
3919 // Relocate the field with the offset of the GOT entry for
3920 // the module index.
3921 unsigned int got_offset;
3922 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3923 - target->got_size());
3924 value = target->got_plt_section()->address() + got_offset;
3925 Relocate_functions<size, false>::pcrela32(view, value, addend,
3926 address);
3927 break;
3928 }
3929 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3930 _("unsupported reloc %u"), r_type);
3931 break;
3932
3933 case elfcpp::R_X86_64_DTPOFF32:
3934 // This relocation type is used in debugging information.
3935 // In that case we need to not optimize the value. If the
3936 // section is not executable, then we assume we should not
3937 // optimize this reloc. See comments above for R_X86_64_TLSGD,
3938 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3939 // R_X86_64_TLSLD.
3940 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3941 {
3942 if (tls_segment == NULL)
3943 {
3944 gold_assert(parameters->errors()->error_count() > 0
3945 || issue_undefined_symbol_error(gsym));
3946 return;
3947 }
3948 value -= tls_segment->memsz();
3949 }
3950 Relocate_functions<size, false>::rela32(view, value, addend);
3951 break;
3952
3953 case elfcpp::R_X86_64_DTPOFF64:
3954 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3955 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3956 {
3957 if (tls_segment == NULL)
3958 {
3959 gold_assert(parameters->errors()->error_count() > 0
3960 || issue_undefined_symbol_error(gsym));
3961 return;
3962 }
3963 value -= tls_segment->memsz();
3964 }
3965 Relocate_functions<size, false>::rela64(view, value, addend);
3966 break;
3967
3968 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3969 if (gsym != NULL
3970 && gsym->is_undefined()
3971 && parameters->options().output_is_executable())
3972 {
3973 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3974 NULL, rela,
3975 r_type, value, view,
3976 view_size);
3977 break;
3978 }
3979 else if (optimized_type == tls::TLSOPT_TO_LE)
3980 {
3981 if (tls_segment == NULL)
3982 {
3983 gold_assert(parameters->errors()->error_count() > 0
3984 || issue_undefined_symbol_error(gsym));
3985 return;
3986 }
3987 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3988 tls_segment, rela,
3989 r_type, value, view,
3990 view_size);
3991 break;
3992 }
3993 else if (optimized_type == tls::TLSOPT_NONE)
3994 {
3995 // Relocate the field with the offset of the GOT entry for
3996 // the tp-relative offset of the symbol.
3997 unsigned int got_offset;
3998 if (gsym != NULL)
3999 {
4000 gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
4001 got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
4002 - target->got_size());
4003 }
4004 else
4005 {
4006 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4007 gold_assert(object->local_has_got_offset(r_sym,
4008 GOT_TYPE_TLS_OFFSET));
4009 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
4010 - target->got_size());
4011 }
4012 value = target->got_plt_section()->address() + got_offset;
4013 Relocate_functions<size, false>::pcrela32(view, value, addend,
4014 address);
4015 break;
4016 }
4017 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4018 _("unsupported reloc type %u"),
4019 r_type);
4020 break;
4021
4022 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4023 if (tls_segment == NULL)
4024 {
4025 gold_assert(parameters->errors()->error_count() > 0
4026 || issue_undefined_symbol_error(gsym));
4027 return;
4028 }
4029 value -= tls_segment->memsz();
4030 Relocate_functions<size, false>::rela32(view, value, addend);
4031 break;
4032 }
4033 }
4034
4035 // Do a relocation in which we convert a TLS General-Dynamic to an
4036 // Initial-Exec.
4037
4038 template<int size>
4039 inline void
4040 Target_x86_64<size>::Relocate::tls_gd_to_ie(
4041 const Relocate_info<size, false>* relinfo,
4042 size_t relnum,
4043 const elfcpp::Rela<size, false>& rela,
4044 unsigned int,
4045 typename elfcpp::Elf_types<size>::Elf_Addr value,
4046 unsigned char* view,
4047 typename elfcpp::Elf_types<size>::Elf_Addr address,
4048 section_size_type view_size)
4049 {
4050 // For SIZE == 64:
4051 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4052 // .word 0x6666; rex64; call __tls_get_addr
4053 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4054 // For SIZE == 32:
4055 // leaq foo@tlsgd(%rip),%rdi;
4056 // .word 0x6666; rex64; call __tls_get_addr
4057 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4058
4059 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4060 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4061 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
4062
4063 if (size == 64)
4064 {
4065 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4066 -4);
4067 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4068 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4069 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4070 16);
4071 }
4072 else
4073 {
4074 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4075 -3);
4076 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4077 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4078 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4079 15);
4080 }
4081
4082 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4083 Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
4084 address);
4085
4086 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4087 // We can skip it.
4088 this->skip_call_tls_get_addr_ = true;
4089 }
4090
4091 // Do a relocation in which we convert a TLS General-Dynamic to a
4092 // Local-Exec.
4093
4094 template<int size>
4095 inline void
4096 Target_x86_64<size>::Relocate::tls_gd_to_le(
4097 const Relocate_info<size, false>* relinfo,
4098 size_t relnum,
4099 Output_segment* tls_segment,
4100 const elfcpp::Rela<size, false>& rela,
4101 unsigned int,
4102 typename elfcpp::Elf_types<size>::Elf_Addr value,
4103 unsigned char* view,
4104 section_size_type view_size)
4105 {
4106 // For SIZE == 64:
4107 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4108 // .word 0x6666; rex64; call __tls_get_addr
4109 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4110 // For SIZE == 32:
4111 // leaq foo@tlsgd(%rip),%rdi;
4112 // .word 0x6666; rex64; call __tls_get_addr
4113 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4114
4115 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4116 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4117 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
4118
4119 if (size == 64)
4120 {
4121 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4122 -4);
4123 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4124 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4125 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4126 16);
4127 }
4128 else
4129 {
4130 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4131 -3);
4132 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4133 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4134
4135 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4136 15);
4137 }
4138
4139 value -= tls_segment->memsz();
4140 Relocate_functions<size, false>::rela32(view + 8, value, 0);
4141
4142 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4143 // We can skip it.
4144 this->skip_call_tls_get_addr_ = true;
4145 }
4146
4147 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4148
4149 template<int size>
4150 inline void
4151 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
4152 const Relocate_info<size, false>* relinfo,
4153 size_t relnum,
4154 const elfcpp::Rela<size, false>& rela,
4155 unsigned int r_type,
4156 typename elfcpp::Elf_types<size>::Elf_Addr value,
4157 unsigned char* view,
4158 typename elfcpp::Elf_types<size>::Elf_Addr address,
4159 section_size_type view_size)
4160 {
4161 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4162 {
4163 // leaq foo@tlsdesc(%rip), %rax
4164 // ==> movq foo@gottpoff(%rip), %rax
4165 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4166 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4167 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4168 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4169 view[-2] = 0x8b;
4170 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4171 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
4172 }
4173 else
4174 {
4175 // call *foo@tlscall(%rax)
4176 // ==> nop; nop
4177 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4178 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4179 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4180 view[0] == 0xff && view[1] == 0x10);
4181 view[0] = 0x66;
4182 view[1] = 0x90;
4183 }
4184 }
4185
4186 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4187
4188 template<int size>
4189 inline void
4190 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
4191 const Relocate_info<size, false>* relinfo,
4192 size_t relnum,
4193 Output_segment* tls_segment,
4194 const elfcpp::Rela<size, false>& rela,
4195 unsigned int r_type,
4196 typename elfcpp::Elf_types<size>::Elf_Addr value,
4197 unsigned char* view,
4198 section_size_type view_size)
4199 {
4200 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4201 {
4202 // leaq foo@tlsdesc(%rip), %rax
4203 // ==> movq foo@tpoff, %rax
4204 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4205 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4206 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4207 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4208 view[-2] = 0xc7;
4209 view[-1] = 0xc0;
4210 value -= tls_segment->memsz();
4211 Relocate_functions<size, false>::rela32(view, value, 0);
4212 }
4213 else
4214 {
4215 // call *foo@tlscall(%rax)
4216 // ==> nop; nop
4217 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4218 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4219 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4220 view[0] == 0xff && view[1] == 0x10);
4221 view[0] = 0x66;
4222 view[1] = 0x90;
4223 }
4224 }
4225
4226 template<int size>
4227 inline void
4228 Target_x86_64<size>::Relocate::tls_ld_to_le(
4229 const Relocate_info<size, false>* relinfo,
4230 size_t relnum,
4231 Output_segment*,
4232 const elfcpp::Rela<size, false>& rela,
4233 unsigned int,
4234 typename elfcpp::Elf_types<size>::Elf_Addr,
4235 unsigned char* view,
4236 section_size_type view_size)
4237 {
4238 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4239 // For SIZE == 64:
4240 // ... leq foo@dtpoff(%rax),%reg
4241 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4242 // For SIZE == 32:
4243 // ... leq foo@dtpoff(%rax),%reg
4244 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4245
4246 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4247 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
4248
4249 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4250 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
4251
4252 tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
4253
4254 if (size == 64)
4255 memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4256 else
4257 memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4258
4259 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4260 // We can skip it.
4261 this->skip_call_tls_get_addr_ = true;
4262 }
4263
4264 // Do a relocation in which we convert a TLS Initial-Exec to a
4265 // Local-Exec.
4266
4267 template<int size>
4268 inline void
4269 Target_x86_64<size>::Relocate::tls_ie_to_le(
4270 const Relocate_info<size, false>* relinfo,
4271 size_t relnum,
4272 Output_segment* tls_segment,
4273 const elfcpp::Rela<size, false>& rela,
4274 unsigned int,
4275 typename elfcpp::Elf_types<size>::Elf_Addr value,
4276 unsigned char* view,
4277 section_size_type view_size)
4278 {
4279 // We need to examine the opcodes to figure out which instruction we
4280 // are looking at.
4281
4282 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4283 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4284
4285 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4286 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4287
4288 unsigned char op1 = view[-3];
4289 unsigned char op2 = view[-2];
4290 unsigned char op3 = view[-1];
4291 unsigned char reg = op3 >> 3;
4292
4293 if (op2 == 0x8b)
4294 {
4295 // movq
4296 if (op1 == 0x4c)
4297 view[-3] = 0x49;
4298 else if (size == 32 && op1 == 0x44)
4299 view[-3] = 0x41;
4300 view[-2] = 0xc7;
4301 view[-1] = 0xc0 | reg;
4302 }
4303 else if (reg == 4)
4304 {
4305 // Special handling for %rsp.
4306 if (op1 == 0x4c)
4307 view[-3] = 0x49;
4308 else if (size == 32 && op1 == 0x44)
4309 view[-3] = 0x41;
4310 view[-2] = 0x81;
4311 view[-1] = 0xc0 | reg;
4312 }
4313 else
4314 {
4315 // addq
4316 if (op1 == 0x4c)
4317 view[-3] = 0x4d;
4318 else if (size == 32 && op1 == 0x44)
4319 view[-3] = 0x45;
4320 view[-2] = 0x8d;
4321 view[-1] = 0x80 | reg | (reg << 3);
4322 }
4323
4324 if (tls_segment != NULL)
4325 value -= tls_segment->memsz();
4326 Relocate_functions<size, false>::rela32(view, value, 0);
4327 }
4328
4329 // Relocate section data.
4330
4331 template<int size>
4332 void
4333 Target_x86_64<size>::relocate_section(
4334 const Relocate_info<size, false>* relinfo,
4335 unsigned int sh_type,
4336 const unsigned char* prelocs,
4337 size_t reloc_count,
4338 Output_section* output_section,
4339 bool needs_special_offset_handling,
4340 unsigned char* view,
4341 typename elfcpp::Elf_types<size>::Elf_Addr address,
4342 section_size_type view_size,
4343 const Reloc_symbol_changes* reloc_symbol_changes)
4344 {
4345 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4346 Classify_reloc;
4347
4348 gold_assert(sh_type == elfcpp::SHT_RELA);
4349
4350 gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
4351 gold::Default_comdat_behavior, Classify_reloc>(
4352 relinfo,
4353 this,
4354 prelocs,
4355 reloc_count,
4356 output_section,
4357 needs_special_offset_handling,
4358 view,
4359 address,
4360 view_size,
4361 reloc_symbol_changes);
4362 }
4363
4364 // Apply an incremental relocation. Incremental relocations always refer
4365 // to global symbols.
4366
4367 template<int size>
4368 void
4369 Target_x86_64<size>::apply_relocation(
4370 const Relocate_info<size, false>* relinfo,
4371 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
4372 unsigned int r_type,
4373 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
4374 const Symbol* gsym,
4375 unsigned char* view,
4376 typename elfcpp::Elf_types<size>::Elf_Addr address,
4377 section_size_type view_size)
4378 {
4379 gold::apply_relocation<size, false, Target_x86_64<size>,
4380 typename Target_x86_64<size>::Relocate>(
4381 relinfo,
4382 this,
4383 r_offset,
4384 r_type,
4385 r_addend,
4386 gsym,
4387 view,
4388 address,
4389 view_size);
4390 }
4391
4392 // Scan the relocs during a relocatable link.
4393
4394 template<int size>
4395 void
4396 Target_x86_64<size>::scan_relocatable_relocs(
4397 Symbol_table* symtab,
4398 Layout* layout,
4399 Sized_relobj_file<size, false>* object,
4400 unsigned int data_shndx,
4401 unsigned int sh_type,
4402 const unsigned char* prelocs,
4403 size_t reloc_count,
4404 Output_section* output_section,
4405 bool needs_special_offset_handling,
4406 size_t local_symbol_count,
4407 const unsigned char* plocal_symbols,
4408 Relocatable_relocs* rr)
4409 {
4410 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4411 Classify_reloc;
4412 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
4413 Scan_relocatable_relocs;
4414
4415 gold_assert(sh_type == elfcpp::SHT_RELA);
4416
4417 gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
4418 symtab,
4419 layout,
4420 object,
4421 data_shndx,
4422 prelocs,
4423 reloc_count,
4424 output_section,
4425 needs_special_offset_handling,
4426 local_symbol_count,
4427 plocal_symbols,
4428 rr);
4429 }
4430
4431 // Scan the relocs for --emit-relocs.
4432
4433 template<int size>
4434 void
4435 Target_x86_64<size>::emit_relocs_scan(
4436 Symbol_table* symtab,
4437 Layout* layout,
4438 Sized_relobj_file<size, false>* object,
4439 unsigned int data_shndx,
4440 unsigned int sh_type,
4441 const unsigned char* prelocs,
4442 size_t reloc_count,
4443 Output_section* output_section,
4444 bool needs_special_offset_handling,
4445 size_t local_symbol_count,
4446 const unsigned char* plocal_syms,
4447 Relocatable_relocs* rr)
4448 {
4449 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4450 Classify_reloc;
4451 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
4452 Emit_relocs_strategy;
4453
4454 gold_assert(sh_type == elfcpp::SHT_RELA);
4455
4456 gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
4457 symtab,
4458 layout,
4459 object,
4460 data_shndx,
4461 prelocs,
4462 reloc_count,
4463 output_section,
4464 needs_special_offset_handling,
4465 local_symbol_count,
4466 plocal_syms,
4467 rr);
4468 }
4469
4470 // Relocate a section during a relocatable link.
4471
4472 template<int size>
4473 void
4474 Target_x86_64<size>::relocate_relocs(
4475 const Relocate_info<size, false>* relinfo,
4476 unsigned int sh_type,
4477 const unsigned char* prelocs,
4478 size_t reloc_count,
4479 Output_section* output_section,
4480 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
4481 unsigned char* view,
4482 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
4483 section_size_type view_size,
4484 unsigned char* reloc_view,
4485 section_size_type reloc_view_size)
4486 {
4487 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4488 Classify_reloc;
4489
4490 gold_assert(sh_type == elfcpp::SHT_RELA);
4491
4492 gold::relocate_relocs<size, false, Classify_reloc>(
4493 relinfo,
4494 prelocs,
4495 reloc_count,
4496 output_section,
4497 offset_in_output_section,
4498 view,
4499 view_address,
4500 view_size,
4501 reloc_view,
4502 reloc_view_size);
4503 }
4504
4505 // Return the value to use for a dynamic which requires special
4506 // treatment. This is how we support equality comparisons of function
4507 // pointers across shared library boundaries, as described in the
4508 // processor specific ABI supplement.
4509
4510 template<int size>
4511 uint64_t
4512 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
4513 {
4514 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
4515 return this->plt_address_for_global(gsym);
4516 }
4517
4518 // Return a string used to fill a code section with nops to take up
4519 // the specified length.
4520
4521 template<int size>
4522 std::string
4523 Target_x86_64<size>::do_code_fill(section_size_type length) const
4524 {
4525 if (length >= 16)
4526 {
4527 // Build a jmpq instruction to skip over the bytes.
4528 unsigned char jmp[5];
4529 jmp[0] = 0xe9;
4530 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
4531 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
4532 + std::string(length - 5, static_cast<char>(0x90)));
4533 }
4534
4535 // Nop sequences of various lengths.
4536 const char nop1[1] = { '\x90' }; // nop
4537 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
4538 const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4539 const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
4540 '\x00'};
4541 const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
4542 '\x00', '\x00' };
4543 const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
4544 '\x44', '\x00', '\x00' };
4545 const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
4546 '\x00', '\x00', '\x00',
4547 '\x00' };
4548 const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
4549 '\x00', '\x00', '\x00',
4550 '\x00', '\x00' };
4551 const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
4552 '\x84', '\x00', '\x00',
4553 '\x00', '\x00', '\x00' };
4554 const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4555 '\x1f', '\x84', '\x00',
4556 '\x00', '\x00', '\x00',
4557 '\x00' };
4558 const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
4559 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4560 '\x00', '\x00', '\x00',
4561 '\x00', '\x00' };
4562 const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
4563 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4564 '\x84', '\x00', '\x00',
4565 '\x00', '\x00', '\x00' };
4566 const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4567 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4568 '\x1f', '\x84', '\x00',
4569 '\x00', '\x00', '\x00',
4570 '\x00' };
4571 const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4572 '\x66', '\x66', '\x2e', // data16
4573 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4574 '\x00', '\x00', '\x00',
4575 '\x00', '\x00' };
4576 const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4577 '\x66', '\x66', '\x66', // data16; data16
4578 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4579 '\x84', '\x00', '\x00',
4580 '\x00', '\x00', '\x00' };
4581
4582 const char* nops[16] = {
4583 NULL,
4584 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
4585 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
4586 };
4587
4588 return std::string(nops[length], length);
4589 }
4590
4591 // Return the addend to use for a target specific relocation. The
4592 // only target specific relocation is R_X86_64_TLSDESC for a local
4593 // symbol. We want to set the addend is the offset of the local
4594 // symbol in the TLS segment.
4595
4596 template<int size>
4597 uint64_t
4598 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
4599 uint64_t) const
4600 {
4601 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
4602 uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
4603 gold_assert(intarg < this->tlsdesc_reloc_info_.size());
4604 const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
4605 const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
4606 gold_assert(psymval->is_tls_symbol());
4607 // The value of a TLS symbol is the offset in the TLS segment.
4608 return psymval->value(ti.object, 0);
4609 }
4610
4611 // Return the value to use for the base of a DW_EH_PE_datarel offset
4612 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
4613 // assembler can not write out the difference between two labels in
4614 // different sections, so instead of using a pc-relative value they
4615 // use an offset from the GOT.
4616
4617 template<int size>
4618 uint64_t
4619 Target_x86_64<size>::do_ehframe_datarel_base() const
4620 {
4621 gold_assert(this->global_offset_table_ != NULL);
4622 Symbol* sym = this->global_offset_table_;
4623 Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
4624 return ssym->value();
4625 }
4626
4627 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4628 // compiled with -fsplit-stack. The function calls non-split-stack
4629 // code. We have to change the function so that it always ensures
4630 // that it has enough stack space to run some random function.
4631
4632 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
4633 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
4634 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
4635
4636 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
4637 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
4638 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
4639
4640 template<int size>
4641 void
4642 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
4643 section_offset_type fnoffset,
4644 section_size_type fnsize,
4645 const unsigned char*,
4646 size_t,
4647 unsigned char* view,
4648 section_size_type view_size,
4649 std::string* from,
4650 std::string* to) const
4651 {
4652 const char* const cmp_insn = reinterpret_cast<const char*>
4653 (size == 32 ? cmp_insn_32 : cmp_insn_64);
4654 const char* const lea_r10_insn = reinterpret_cast<const char*>
4655 (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
4656 const char* const lea_r11_insn = reinterpret_cast<const char*>
4657 (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
4658
4659 const size_t cmp_insn_len =
4660 (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
4661 const size_t lea_r10_insn_len =
4662 (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
4663 const size_t lea_r11_insn_len =
4664 (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
4665 const size_t nop_len = (size == 32 ? 7 : 8);
4666
4667 // The function starts with a comparison of the stack pointer and a
4668 // field in the TCB. This is followed by a jump.
4669
4670 // cmp %fs:NN,%rsp
4671 if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
4672 && fnsize > nop_len + 1)
4673 {
4674 // We will call __morestack if the carry flag is set after this
4675 // comparison. We turn the comparison into an stc instruction
4676 // and some nops.
4677 view[fnoffset] = '\xf9';
4678 this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
4679 }
4680 // lea NN(%rsp),%r10
4681 // lea NN(%rsp),%r11
4682 else if ((this->match_view(view, view_size, fnoffset,
4683 lea_r10_insn, lea_r10_insn_len)
4684 || this->match_view(view, view_size, fnoffset,
4685 lea_r11_insn, lea_r11_insn_len))
4686 && fnsize > 8)
4687 {
4688 // This is loading an offset from the stack pointer for a
4689 // comparison. The offset is negative, so we decrease the
4690 // offset by the amount of space we need for the stack. This
4691 // means we will avoid calling __morestack if there happens to
4692 // be plenty of space on the stack already.
4693 unsigned char* pval = view + fnoffset + 4;
4694 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4695 val -= parameters->options().split_stack_adjust_size();
4696 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4697 }
4698 else
4699 {
4700 if (!object->has_no_split_stack())
4701 object->error(_("failed to match split-stack sequence at "
4702 "section %u offset %0zx"),
4703 shndx, static_cast<size_t>(fnoffset));
4704 return;
4705 }
4706
4707 // We have to change the function so that it calls
4708 // __morestack_non_split instead of __morestack. The former will
4709 // allocate additional stack space.
4710 *from = "__morestack";
4711 *to = "__morestack_non_split";
4712 }
4713
4714 // The selector for x86_64 object files. Note this is never instantiated
4715 // directly. It's only used in Target_selector_x86_64_nacl, below.
4716
4717 template<int size>
4718 class Target_selector_x86_64 : public Target_selector_freebsd
4719 {
4720 public:
4721 Target_selector_x86_64()
4722 : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
4723 (size == 64
4724 ? "elf64-x86-64" : "elf32-x86-64"),
4725 (size == 64
4726 ? "elf64-x86-64-freebsd"
4727 : "elf32-x86-64-freebsd"),
4728 (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
4729 { }
4730
4731 Target*
4732 do_instantiate_target()
4733 { return new Target_x86_64<size>(); }
4734
4735 };
4736
4737 // NaCl variant. It uses different PLT contents.
4738
4739 template<int size>
4740 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
4741 {
4742 public:
4743 Output_data_plt_x86_64_nacl(Layout* layout,
4744 Output_data_got<64, false>* got,
4745 Output_data_got_plt_x86_64* got_plt,
4746 Output_data_space* got_irelative)
4747 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4748 got, got_plt, got_irelative)
4749 { }
4750
4751 Output_data_plt_x86_64_nacl(Layout* layout,
4752 Output_data_got<64, false>* got,
4753 Output_data_got_plt_x86_64* got_plt,
4754 Output_data_space* got_irelative,
4755 unsigned int plt_count)
4756 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4757 got, got_plt, got_irelative,
4758 plt_count)
4759 { }
4760
4761 protected:
4762 virtual unsigned int
4763 do_get_plt_entry_size() const
4764 { return plt_entry_size; }
4765
4766 virtual void
4767 do_add_eh_frame(Layout* layout)
4768 {
4769 layout->add_eh_frame_for_plt(this,
4770 this->plt_eh_frame_cie,
4771 this->plt_eh_frame_cie_size,
4772 plt_eh_frame_fde,
4773 plt_eh_frame_fde_size);
4774 }
4775
4776 virtual void
4777 do_fill_first_plt_entry(unsigned char* pov,
4778 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
4779 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
4780
4781 virtual unsigned int
4782 do_fill_plt_entry(unsigned char* pov,
4783 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4784 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4785 unsigned int got_offset,
4786 unsigned int plt_offset,
4787 unsigned int plt_index);
4788
4789 virtual void
4790 do_fill_tlsdesc_entry(unsigned char* pov,
4791 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4792 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4793 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4794 unsigned int tlsdesc_got_offset,
4795 unsigned int plt_offset);
4796
4797 private:
4798 // The size of an entry in the PLT.
4799 static const int plt_entry_size = 64;
4800
4801 // The first entry in the PLT.
4802 static const unsigned char first_plt_entry[plt_entry_size];
4803
4804 // Other entries in the PLT for an executable.
4805 static const unsigned char plt_entry[plt_entry_size];
4806
4807 // The reserved TLSDESC entry in the PLT for an executable.
4808 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
4809
4810 // The .eh_frame unwind information for the PLT.
4811 static const int plt_eh_frame_fde_size = 32;
4812 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4813 };
4814
4815 template<int size>
4816 class Target_x86_64_nacl : public Target_x86_64<size>
4817 {
4818 public:
4819 Target_x86_64_nacl()
4820 : Target_x86_64<size>(&x86_64_nacl_info)
4821 { }
4822
4823 virtual Output_data_plt_x86_64<size>*
4824 do_make_data_plt(Layout* layout,
4825 Output_data_got<64, false>* got,
4826 Output_data_got_plt_x86_64* got_plt,
4827 Output_data_space* got_irelative)
4828 {
4829 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4830 got_irelative);
4831 }
4832
4833 virtual Output_data_plt_x86_64<size>*
4834 do_make_data_plt(Layout* layout,
4835 Output_data_got<64, false>* got,
4836 Output_data_got_plt_x86_64* got_plt,
4837 Output_data_space* got_irelative,
4838 unsigned int plt_count)
4839 {
4840 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4841 got_irelative,
4842 plt_count);
4843 }
4844
4845 virtual std::string
4846 do_code_fill(section_size_type length) const;
4847
4848 private:
4849 static const Target::Target_info x86_64_nacl_info;
4850 };
4851
4852 template<>
4853 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
4854 {
4855 64, // size
4856 false, // is_big_endian
4857 elfcpp::EM_X86_64, // machine_code
4858 false, // has_make_symbol
4859 false, // has_resolve
4860 true, // has_code_fill
4861 true, // is_default_stack_executable
4862 true, // can_icf_inline_merge_sections
4863 '\0', // wrap_char
4864 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4865 0x20000, // default_text_segment_address
4866 0x10000, // abi_pagesize (overridable by -z max-page-size)
4867 0x10000, // common_pagesize (overridable by -z common-page-size)
4868 true, // isolate_execinstr
4869 0x10000000, // rosegment_gap
4870 elfcpp::SHN_UNDEF, // small_common_shndx
4871 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
4872 0, // small_common_section_flags
4873 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
4874 NULL, // attributes_section
4875 NULL, // attributes_vendor
4876 "_start", // entry_symbol_name
4877 32, // hash_entry_size
4878 };
4879
4880 template<>
4881 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
4882 {
4883 32, // size
4884 false, // is_big_endian
4885 elfcpp::EM_X86_64, // machine_code
4886 false, // has_make_symbol
4887 false, // has_resolve
4888 true, // has_code_fill
4889 true, // is_default_stack_executable
4890 true, // can_icf_inline_merge_sections
4891 '\0', // wrap_char
4892 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4893 0x20000, // default_text_segment_address
4894 0x10000, // abi_pagesize (overridable by -z max-page-size)
4895 0x10000, // common_pagesize (overridable by -z common-page-size)
4896 true, // isolate_execinstr
4897 0x10000000, // rosegment_gap
4898 elfcpp::SHN_UNDEF, // small_common_shndx
4899 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
4900 0, // small_common_section_flags
4901 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
4902 NULL, // attributes_section
4903 NULL, // attributes_vendor
4904 "_start", // entry_symbol_name
4905 32, // hash_entry_size
4906 };
4907
4908 #define NACLMASK 0xe0 // 32-byte alignment mask.
4909
4910 // The first entry in the PLT.
4911
4912 template<int size>
4913 const unsigned char
4914 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
4915 {
4916 0xff, 0x35, // pushq contents of memory address
4917 0, 0, 0, 0, // replaced with address of .got + 8
4918 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
4919 0, 0, 0, 0, // replaced with address of .got + 16
4920 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4921 0x4d, 0x01, 0xfb, // add %r15, %r11
4922 0x41, 0xff, 0xe3, // jmpq *%r11
4923
4924 // 9-byte nop sequence to pad out to the next 32-byte boundary.
4925 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4926
4927 // 32 bytes of nop to pad out to the standard size
4928 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4929 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4930 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4931 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4932 0x66, // excess data32 prefix
4933 0x90 // nop
4934 };
4935
4936 template<int size>
4937 void
4938 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
4939 unsigned char* pov,
4940 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4941 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
4942 {
4943 memcpy(pov, first_plt_entry, plt_entry_size);
4944 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4945 (got_address + 8
4946 - (plt_address + 2 + 4)));
4947 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4948 (got_address + 16
4949 - (plt_address + 9 + 4)));
4950 }
4951
4952 // Subsequent entries in the PLT.
4953
4954 template<int size>
4955 const unsigned char
4956 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
4957 {
4958 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
4959 0, 0, 0, 0, // replaced with address of symbol in .got
4960 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
4961 0x4d, 0x01, 0xfb, // add %r15, %r11
4962 0x41, 0xff, 0xe3, // jmpq *%r11
4963
4964 // 15-byte nop sequence to pad out to the next 32-byte boundary.
4965 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4966 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4967
4968 // Lazy GOT entries point here (32-byte aligned).
4969 0x68, // pushq immediate
4970 0, 0, 0, 0, // replaced with index into relocation table
4971 0xe9, // jmp relative
4972 0, 0, 0, 0, // replaced with offset to start of .plt0
4973
4974 // 22 bytes of nop to pad out to the standard size.
4975 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
4976 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4977 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
4978 };
4979
4980 template<int size>
4981 unsigned int
4982 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
4983 unsigned char* pov,
4984 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4985 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4986 unsigned int got_offset,
4987 unsigned int plt_offset,
4988 unsigned int plt_index)
4989 {
4990 memcpy(pov, plt_entry, plt_entry_size);
4991 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
4992 (got_address + got_offset
4993 - (plt_address + plt_offset
4994 + 3 + 4)));
4995
4996 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
4997 elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
4998 - (plt_offset + 38 + 4));
4999
5000 return 32;
5001 }
5002
5003 // The reserved TLSDESC entry in the PLT.
5004
5005 template<int size>
5006 const unsigned char
5007 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
5008 {
5009 0xff, 0x35, // pushq x(%rip)
5010 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
5011 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
5012 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
5013 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
5014 0x4d, 0x01, 0xfb, // add %r15, %r11
5015 0x41, 0xff, 0xe3, // jmpq *%r11
5016
5017 // 41 bytes of nop to pad out to the standard size.
5018 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5019 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5020 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5021 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5022 0x66, 0x66, // excess data32 prefixes
5023 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5024 };
5025
5026 template<int size>
5027 void
5028 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
5029 unsigned char* pov,
5030 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5031 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
5032 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
5033 unsigned int tlsdesc_got_offset,
5034 unsigned int plt_offset)
5035 {
5036 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
5037 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
5038 (got_address + 8
5039 - (plt_address + plt_offset
5040 + 2 + 4)));
5041 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
5042 (got_base
5043 + tlsdesc_got_offset
5044 - (plt_address + plt_offset
5045 + 9 + 4)));
5046 }
5047
5048 // The .eh_frame unwind information for the PLT.
5049
5050 template<int size>
5051 const unsigned char
5052 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
5053 {
5054 0, 0, 0, 0, // Replaced with offset to .plt.
5055 0, 0, 0, 0, // Replaced with size of .plt.
5056 0, // Augmentation size.
5057 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
5058 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
5059 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
5060 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
5061 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
5062 13, // Block length.
5063 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
5064 elfcpp::DW_OP_breg16, 0, // Push %rip.
5065 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
5066 elfcpp::DW_OP_and, // & (%rip & 0x3f).
5067 elfcpp::DW_OP_const1u, 37, // Push 0x25.
5068 elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25)
5069 elfcpp::DW_OP_lit3, // Push 3.
5070 elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3)
5071 elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5072 elfcpp::DW_CFA_nop, // Align to 32 bytes.
5073 elfcpp::DW_CFA_nop
5074 };
5075
5076 // Return a string used to fill a code section with nops.
5077 // For NaCl, long NOPs are only valid if they do not cross
5078 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5079 template<int size>
5080 std::string
5081 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
5082 {
5083 return std::string(length, static_cast<char>(0x90));
5084 }
5085
5086 // The selector for x86_64-nacl object files.
5087
5088 template<int size>
5089 class Target_selector_x86_64_nacl
5090 : public Target_selector_nacl<Target_selector_x86_64<size>,
5091 Target_x86_64_nacl<size> >
5092 {
5093 public:
5094 Target_selector_x86_64_nacl()
5095 : Target_selector_nacl<Target_selector_x86_64<size>,
5096 Target_x86_64_nacl<size> >("x86-64",
5097 size == 64
5098 ? "elf64-x86-64-nacl"
5099 : "elf32-x86-64-nacl",
5100 size == 64
5101 ? "elf_x86_64_nacl"
5102 : "elf32_x86_64_nacl")
5103 { }
5104 };
5105
5106 Target_selector_x86_64_nacl<64> target_selector_x86_64;
5107 Target_selector_x86_64_nacl<32> target_selector_x32;
5108
5109 } // End anonymous namespace.
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