Fix type checking errors.
[deliverable/binutils-gdb.git] / gold / x86_64.cc
1 // x86_64.cc -- x86_64 target support for gold.
2
3 // Copyright (C) 2006-2018 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 // Get count of regular PLT entries.
183 unsigned int
184 regular_count() const
185 { return this->count_; }
186
187 // Return the total number of PLT entries.
188 unsigned int
189 entry_count() const
190 { return this->count_ + this->irelative_count_; }
191
192 // Return the offset of the first non-reserved PLT entry.
193 unsigned int
194 first_plt_entry_offset()
195 { return this->get_plt_entry_size(); }
196
197 // Return the size of a PLT entry.
198 unsigned int
199 get_plt_entry_size() const
200 { return this->do_get_plt_entry_size(); }
201
202 // Reserve a slot in the PLT for an existing symbol in an incremental update.
203 void
204 reserve_slot(unsigned int plt_index)
205 {
206 this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(),
207 (plt_index + 2) * this->get_plt_entry_size());
208 }
209
210 // Return the PLT address to use for a global symbol.
211 uint64_t
212 address_for_global(const Symbol* sym)
213 { return do_address_for_global(sym); }
214
215 // Return the PLT address to use for a local symbol.
216 uint64_t
217 address_for_local(const Relobj* obj, unsigned int symndx)
218 { return do_address_for_local(obj, symndx); }
219
220 // Add .eh_frame information for the PLT.
221 void
222 add_eh_frame(Layout* layout)
223 { this->do_add_eh_frame(layout); }
224
225 protected:
226 Output_data_got<64, false>*
227 got() const
228 { return this->got_; }
229
230 Output_data_got_plt_x86_64*
231 got_plt() const
232 { return this->got_plt_; }
233
234 Output_data_space*
235 got_irelative() const
236 { return this->got_irelative_; }
237
238 // Fill in the first PLT entry.
239 void
240 fill_first_plt_entry(unsigned char* pov,
241 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
242 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
243 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
244
245 // Fill in a normal PLT entry. Returns the offset into the entry that
246 // should be the initial GOT slot value.
247 unsigned int
248 fill_plt_entry(unsigned char* pov,
249 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
250 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
251 unsigned int got_offset,
252 unsigned int plt_offset,
253 unsigned int plt_index)
254 {
255 return this->do_fill_plt_entry(pov, got_address, plt_address,
256 got_offset, plt_offset, plt_index);
257 }
258
259 // Fill in the reserved TLSDESC PLT entry.
260 void
261 fill_tlsdesc_entry(unsigned char* pov,
262 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
263 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
264 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
265 unsigned int tlsdesc_got_offset,
266 unsigned int plt_offset)
267 {
268 this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
269 tlsdesc_got_offset, plt_offset);
270 }
271
272 virtual unsigned int
273 do_get_plt_entry_size() const = 0;
274
275 virtual void
276 do_fill_first_plt_entry(unsigned char* pov,
277 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
278 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr)
279 = 0;
280
281 virtual unsigned int
282 do_fill_plt_entry(unsigned char* pov,
283 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
284 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
285 unsigned int got_offset,
286 unsigned int plt_offset,
287 unsigned int plt_index) = 0;
288
289 virtual void
290 do_fill_tlsdesc_entry(unsigned char* pov,
291 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
292 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
293 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
294 unsigned int tlsdesc_got_offset,
295 unsigned int plt_offset) = 0;
296
297 // Return the PLT address to use for a global symbol.
298 virtual uint64_t
299 do_address_for_global(const Symbol* sym);
300
301 // Return the PLT address to use for a local symbol.
302 virtual uint64_t
303 do_address_for_local(const Relobj* obj, unsigned int symndx);
304
305 virtual void
306 do_add_eh_frame(Layout* layout) = 0;
307
308 void
309 do_adjust_output_section(Output_section* os);
310
311 // Write to a map file.
312 void
313 do_print_to_mapfile(Mapfile* mapfile) const
314 { mapfile->print_output_data(this, _("** PLT")); }
315
316 // The CIE of the .eh_frame unwind information for the PLT.
317 static const int plt_eh_frame_cie_size = 16;
318 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
319
320 private:
321 // Set the final size.
322 void
323 set_final_data_size();
324
325 // Write out the PLT data.
326 void
327 do_write(Output_file*);
328
329 // The reloc section.
330 Reloc_section* rel_;
331 // The TLSDESC relocs, if necessary. These must follow the regular
332 // PLT relocs.
333 Reloc_section* tlsdesc_rel_;
334 // The IRELATIVE relocs, if necessary. These must follow the
335 // regular PLT relocations and the TLSDESC relocations.
336 Reloc_section* irelative_rel_;
337 // The .got section.
338 Output_data_got<64, false>* got_;
339 // The .got.plt section.
340 Output_data_got_plt_x86_64* got_plt_;
341 // The part of the .got.plt section used for IRELATIVE relocs.
342 Output_data_space* got_irelative_;
343 // The number of PLT entries.
344 unsigned int count_;
345 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
346 // follow the regular PLT entries.
347 unsigned int irelative_count_;
348 // Offset of the reserved TLSDESC_GOT entry when needed.
349 unsigned int tlsdesc_got_offset_;
350 // List of available regions within the section, for incremental
351 // update links.
352 Free_list free_list_;
353 };
354
355 template<int size>
356 class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64<size>
357 {
358 public:
359 Output_data_plt_x86_64_standard(Layout* layout,
360 Output_data_got<64, false>* got,
361 Output_data_got_plt_x86_64* got_plt,
362 Output_data_space* got_irelative)
363 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
364 got, got_plt, got_irelative)
365 { }
366
367 Output_data_plt_x86_64_standard(Layout* layout,
368 Output_data_got<64, false>* got,
369 Output_data_got_plt_x86_64* got_plt,
370 Output_data_space* got_irelative,
371 unsigned int plt_count)
372 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
373 got, got_plt, got_irelative,
374 plt_count)
375 { }
376
377 protected:
378 virtual unsigned int
379 do_get_plt_entry_size() const
380 { return plt_entry_size; }
381
382 virtual void
383 do_add_eh_frame(Layout* layout)
384 {
385 layout->add_eh_frame_for_plt(this,
386 this->plt_eh_frame_cie,
387 this->plt_eh_frame_cie_size,
388 plt_eh_frame_fde,
389 plt_eh_frame_fde_size);
390 }
391
392 virtual void
393 do_fill_first_plt_entry(unsigned char* pov,
394 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
395 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
396
397 virtual unsigned int
398 do_fill_plt_entry(unsigned char* pov,
399 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
400 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
401 unsigned int got_offset,
402 unsigned int plt_offset,
403 unsigned int plt_index);
404
405 virtual void
406 do_fill_tlsdesc_entry(unsigned char* pov,
407 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
408 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
409 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
410 unsigned int tlsdesc_got_offset,
411 unsigned int plt_offset);
412
413 private:
414 // The size of an entry in the PLT.
415 static const int plt_entry_size = 16;
416
417 // The first entry in the PLT.
418 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
419 // procedure linkage table for both programs and shared objects."
420 static const unsigned char first_plt_entry[plt_entry_size];
421
422 // Other entries in the PLT for an executable.
423 static const unsigned char plt_entry[plt_entry_size];
424
425 // The reserved TLSDESC entry in the PLT for an executable.
426 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
427
428 // The .eh_frame unwind information for the PLT.
429 static const int plt_eh_frame_fde_size = 32;
430 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
431 };
432
433 class Output_data_plt_x86_64_bnd : public Output_data_plt_x86_64<64>
434 {
435 public:
436 Output_data_plt_x86_64_bnd(Layout* layout,
437 Output_data_got<64, false>* got,
438 Output_data_got_plt_x86_64* got_plt,
439 Output_data_space* got_irelative)
440 : Output_data_plt_x86_64<64>(layout, plt_entry_size,
441 got, got_plt, got_irelative),
442 aplt_offset_(0)
443 { }
444
445 Output_data_plt_x86_64_bnd(Layout* layout,
446 Output_data_got<64, false>* got,
447 Output_data_got_plt_x86_64* got_plt,
448 Output_data_space* got_irelative,
449 unsigned int plt_count)
450 : Output_data_plt_x86_64<64>(layout, plt_entry_size,
451 got, got_plt, got_irelative,
452 plt_count),
453 aplt_offset_(0)
454 { }
455
456 protected:
457 virtual unsigned int
458 do_get_plt_entry_size() const
459 { return plt_entry_size; }
460
461 // Return the PLT address to use for a global symbol.
462 uint64_t
463 do_address_for_global(const Symbol*);
464
465 // Return the PLT address to use for a local symbol.
466 uint64_t
467 do_address_for_local(const Relobj*, unsigned int symndx);
468
469 virtual void
470 do_add_eh_frame(Layout* layout)
471 {
472 layout->add_eh_frame_for_plt(this,
473 this->plt_eh_frame_cie,
474 this->plt_eh_frame_cie_size,
475 plt_eh_frame_fde,
476 plt_eh_frame_fde_size);
477 }
478
479 virtual void
480 do_fill_first_plt_entry(unsigned char* pov,
481 elfcpp::Elf_types<64>::Elf_Addr got_addr,
482 elfcpp::Elf_types<64>::Elf_Addr plt_addr);
483
484 virtual unsigned int
485 do_fill_plt_entry(unsigned char* pov,
486 elfcpp::Elf_types<64>::Elf_Addr got_address,
487 elfcpp::Elf_types<64>::Elf_Addr plt_address,
488 unsigned int got_offset,
489 unsigned int plt_offset,
490 unsigned int plt_index);
491
492 virtual void
493 do_fill_tlsdesc_entry(unsigned char* pov,
494 elfcpp::Elf_types<64>::Elf_Addr got_address,
495 elfcpp::Elf_types<64>::Elf_Addr plt_address,
496 elfcpp::Elf_types<64>::Elf_Addr got_base,
497 unsigned int tlsdesc_got_offset,
498 unsigned int plt_offset);
499
500 void
501 fill_aplt_entry(unsigned char* pov,
502 elfcpp::Elf_types<64>::Elf_Addr got_address,
503 elfcpp::Elf_types<64>::Elf_Addr plt_address,
504 unsigned int got_offset,
505 unsigned int plt_offset,
506 unsigned int plt_index);
507
508 private:
509 // Set the final size.
510 void
511 set_final_data_size();
512
513 // Write out the BND PLT data.
514 void
515 do_write(Output_file*);
516
517 // Offset of the Additional PLT (if using -z bndplt).
518 unsigned int aplt_offset_;
519
520 // The size of an entry in the PLT.
521 static const int plt_entry_size = 16;
522
523 // The size of an entry in the additional PLT.
524 static const int aplt_entry_size = 8;
525
526 // The first entry in the PLT.
527 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
528 // procedure linkage table for both programs and shared objects."
529 static const unsigned char first_plt_entry[plt_entry_size];
530
531 // Other entries in the PLT for an executable.
532 static const unsigned char plt_entry[plt_entry_size];
533
534 // Entries in the additional PLT.
535 static const unsigned char aplt_entry[aplt_entry_size];
536
537 // The reserved TLSDESC entry in the PLT for an executable.
538 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
539
540 // The .eh_frame unwind information for the PLT.
541 static const int plt_eh_frame_fde_size = 32;
542 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
543 };
544
545 // We use this PLT when Indirect Branch Tracking (IBT) is enabled.
546
547 template <int size>
548 class Output_data_plt_x86_64_ibt : public Output_data_plt_x86_64<size>
549 {
550 public:
551 Output_data_plt_x86_64_ibt(Layout* layout,
552 Output_data_got<64, false>* got,
553 Output_data_got_plt_x86_64* got_plt,
554 Output_data_space* got_irelative)
555 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
556 got, got_plt, got_irelative),
557 aplt_offset_(0)
558 { }
559
560 Output_data_plt_x86_64_ibt(Layout* layout,
561 Output_data_got<64, false>* got,
562 Output_data_got_plt_x86_64* got_plt,
563 Output_data_space* got_irelative,
564 unsigned int plt_count)
565 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
566 got, got_plt, got_irelative,
567 plt_count),
568 aplt_offset_(0)
569 { }
570
571 protected:
572 virtual unsigned int
573 do_get_plt_entry_size() const
574 { return plt_entry_size; }
575
576 // Return the PLT address to use for a global symbol.
577 uint64_t
578 do_address_for_global(const Symbol*);
579
580 // Return the PLT address to use for a local symbol.
581 uint64_t
582 do_address_for_local(const Relobj*, unsigned int symndx);
583
584 virtual void
585 do_add_eh_frame(Layout* layout)
586 {
587 layout->add_eh_frame_for_plt(this,
588 this->plt_eh_frame_cie,
589 this->plt_eh_frame_cie_size,
590 plt_eh_frame_fde,
591 plt_eh_frame_fde_size);
592 }
593
594 virtual void
595 do_fill_first_plt_entry(unsigned char* pov,
596 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
597 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
598
599 virtual unsigned int
600 do_fill_plt_entry(unsigned char* pov,
601 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
602 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
603 unsigned int got_offset,
604 unsigned int plt_offset,
605 unsigned int plt_index);
606
607 virtual void
608 do_fill_tlsdesc_entry(unsigned char* pov,
609 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
610 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
611 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
612 unsigned int tlsdesc_got_offset,
613 unsigned int plt_offset);
614
615 void
616 fill_aplt_entry(unsigned char* pov,
617 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
618 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
619 unsigned int got_offset,
620 unsigned int plt_offset,
621 unsigned int plt_index);
622
623 private:
624 // Set the final size.
625 void
626 set_final_data_size();
627
628 // Write out the BND PLT data.
629 void
630 do_write(Output_file*);
631
632 // Offset of the Additional PLT (if using -z bndplt).
633 unsigned int aplt_offset_;
634
635 // The size of an entry in the PLT.
636 static const int plt_entry_size = 16;
637
638 // The size of an entry in the additional PLT.
639 static const int aplt_entry_size = 16;
640
641 // The first entry in the PLT.
642 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
643 // procedure linkage table for both programs and shared objects."
644 static const unsigned char first_plt_entry[plt_entry_size];
645
646 // Other entries in the PLT for an executable.
647 static const unsigned char plt_entry[plt_entry_size];
648
649 // Entries in the additional PLT.
650 static const unsigned char aplt_entry[aplt_entry_size];
651
652 // The reserved TLSDESC entry in the PLT for an executable.
653 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
654
655 // The .eh_frame unwind information for the PLT.
656 static const int plt_eh_frame_fde_size = 32;
657 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
658 };
659
660 template<int size>
661 class Lazy_view
662 {
663 public:
664 Lazy_view(Sized_relobj_file<size, false>* object, unsigned int data_shndx)
665 : object_(object), data_shndx_(data_shndx), view_(NULL), view_size_(0)
666 { }
667
668 inline unsigned char
669 operator[](size_t offset)
670 {
671 if (this->view_ == NULL)
672 this->view_ = this->object_->section_contents(this->data_shndx_,
673 &this->view_size_,
674 true);
675 if (offset >= this->view_size_)
676 return 0;
677 return this->view_[offset];
678 }
679
680 private:
681 Sized_relobj_file<size, false>* object_;
682 unsigned int data_shndx_;
683 const unsigned char* view_;
684 section_size_type view_size_;
685 };
686
687 // The x86_64 target class.
688 // See the ABI at
689 // http://www.x86-64.org/documentation/abi.pdf
690 // TLS info comes from
691 // http://people.redhat.com/drepper/tls.pdf
692 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
693
694 template<int size>
695 class Target_x86_64 : public Sized_target<size, false>
696 {
697 public:
698 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
699 // uses only Elf64_Rela relocation entries with explicit addends."
700 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
701
702 Target_x86_64(const Target::Target_info* info = &x86_64_info)
703 : Sized_target<size, false>(info),
704 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
705 got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
706 rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
707 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
708 tls_base_symbol_defined_(false), isa_1_used_(0), isa_1_needed_(0),
709 feature_1_(0), object_feature_1_(0), seen_first_object_(false)
710 { }
711
712 // Hook for a new output section.
713 void
714 do_new_output_section(Output_section*) const;
715
716 // Scan the relocations to look for symbol adjustments.
717 void
718 gc_process_relocs(Symbol_table* symtab,
719 Layout* layout,
720 Sized_relobj_file<size, false>* object,
721 unsigned int data_shndx,
722 unsigned int sh_type,
723 const unsigned char* prelocs,
724 size_t reloc_count,
725 Output_section* output_section,
726 bool needs_special_offset_handling,
727 size_t local_symbol_count,
728 const unsigned char* plocal_symbols);
729
730 // Scan the relocations to look for symbol adjustments.
731 void
732 scan_relocs(Symbol_table* symtab,
733 Layout* layout,
734 Sized_relobj_file<size, false>* object,
735 unsigned int data_shndx,
736 unsigned int sh_type,
737 const unsigned char* prelocs,
738 size_t reloc_count,
739 Output_section* output_section,
740 bool needs_special_offset_handling,
741 size_t local_symbol_count,
742 const unsigned char* plocal_symbols);
743
744 // Finalize the sections.
745 void
746 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
747
748 // Return the value to use for a dynamic which requires special
749 // treatment.
750 uint64_t
751 do_dynsym_value(const Symbol*) const;
752
753 // Relocate a section.
754 void
755 relocate_section(const Relocate_info<size, false>*,
756 unsigned int sh_type,
757 const unsigned char* prelocs,
758 size_t reloc_count,
759 Output_section* output_section,
760 bool needs_special_offset_handling,
761 unsigned char* view,
762 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
763 section_size_type view_size,
764 const Reloc_symbol_changes*);
765
766 // Scan the relocs during a relocatable link.
767 void
768 scan_relocatable_relocs(Symbol_table* symtab,
769 Layout* layout,
770 Sized_relobj_file<size, false>* object,
771 unsigned int data_shndx,
772 unsigned int sh_type,
773 const unsigned char* prelocs,
774 size_t reloc_count,
775 Output_section* output_section,
776 bool needs_special_offset_handling,
777 size_t local_symbol_count,
778 const unsigned char* plocal_symbols,
779 Relocatable_relocs*);
780
781 // Scan the relocs for --emit-relocs.
782 void
783 emit_relocs_scan(Symbol_table* symtab,
784 Layout* layout,
785 Sized_relobj_file<size, false>* object,
786 unsigned int data_shndx,
787 unsigned int sh_type,
788 const unsigned char* prelocs,
789 size_t reloc_count,
790 Output_section* output_section,
791 bool needs_special_offset_handling,
792 size_t local_symbol_count,
793 const unsigned char* plocal_syms,
794 Relocatable_relocs* rr);
795
796 // Emit relocations for a section.
797 void
798 relocate_relocs(
799 const Relocate_info<size, false>*,
800 unsigned int sh_type,
801 const unsigned char* prelocs,
802 size_t reloc_count,
803 Output_section* output_section,
804 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
805 unsigned char* view,
806 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
807 section_size_type view_size,
808 unsigned char* reloc_view,
809 section_size_type reloc_view_size);
810
811 // Return a string used to fill a code section with nops.
812 std::string
813 do_code_fill(section_size_type length) const;
814
815 // Return whether SYM is defined by the ABI.
816 bool
817 do_is_defined_by_abi(const Symbol* sym) const
818 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
819
820 // Return the symbol index to use for a target specific relocation.
821 // The only target specific relocation is R_X86_64_TLSDESC for a
822 // local symbol, which is an absolute reloc.
823 unsigned int
824 do_reloc_symbol_index(void*, unsigned int r_type) const
825 {
826 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
827 return 0;
828 }
829
830 // Return the addend to use for a target specific relocation.
831 uint64_t
832 do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
833
834 // Return the PLT section.
835 uint64_t
836 do_plt_address_for_global(const Symbol* gsym) const
837 { return this->plt_section()->address_for_global(gsym); }
838
839 uint64_t
840 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
841 { return this->plt_section()->address_for_local(relobj, symndx); }
842
843 // This function should be defined in targets that can use relocation
844 // types to determine (implemented in local_reloc_may_be_function_pointer
845 // and global_reloc_may_be_function_pointer)
846 // if a function's pointer is taken. ICF uses this in safe mode to only
847 // fold those functions whose pointer is defintely not taken. For x86_64
848 // pie binaries, safe ICF cannot be done by looking at only relocation
849 // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
850 // opcode is checked as well to distinguish a function call from taking
851 // a function's pointer.
852 bool
853 do_can_check_for_function_pointers() const
854 { return true; }
855
856 // Return the base for a DW_EH_PE_datarel encoding.
857 uint64_t
858 do_ehframe_datarel_base() const;
859
860 // Adjust -fsplit-stack code which calls non-split-stack code.
861 void
862 do_calls_non_split(Relobj* object, unsigned int shndx,
863 section_offset_type fnoffset, section_size_type fnsize,
864 const unsigned char* prelocs, size_t reloc_count,
865 unsigned char* view, section_size_type view_size,
866 std::string* from, std::string* to) const;
867
868 // Return the size of the GOT section.
869 section_size_type
870 got_size() const
871 {
872 gold_assert(this->got_ != NULL);
873 return this->got_->data_size();
874 }
875
876 // Return the number of entries in the GOT.
877 unsigned int
878 got_entry_count() const
879 {
880 if (this->got_ == NULL)
881 return 0;
882 return this->got_size() / 8;
883 }
884
885 // Return the number of entries in the PLT.
886 unsigned int
887 plt_entry_count() const;
888
889 // Return the offset of the first non-reserved PLT entry.
890 unsigned int
891 first_plt_entry_offset() const;
892
893 // Return the size of each PLT entry.
894 unsigned int
895 plt_entry_size() const;
896
897 // Return the size of each GOT entry.
898 unsigned int
899 got_entry_size() const
900 { return 8; };
901
902 // Create the GOT section for an incremental update.
903 Output_data_got_base*
904 init_got_plt_for_update(Symbol_table* symtab,
905 Layout* layout,
906 unsigned int got_count,
907 unsigned int plt_count);
908
909 // Reserve a GOT entry for a local symbol, and regenerate any
910 // necessary dynamic relocations.
911 void
912 reserve_local_got_entry(unsigned int got_index,
913 Sized_relobj<size, false>* obj,
914 unsigned int r_sym,
915 unsigned int got_type);
916
917 // Reserve a GOT entry for a global symbol, and regenerate any
918 // necessary dynamic relocations.
919 void
920 reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
921 unsigned int got_type);
922
923 // Register an existing PLT entry for a global symbol.
924 void
925 register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
926 Symbol* gsym);
927
928 // Force a COPY relocation for a given symbol.
929 void
930 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
931
932 // Apply an incremental relocation.
933 void
934 apply_relocation(const Relocate_info<size, false>* relinfo,
935 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
936 unsigned int r_type,
937 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
938 const Symbol* gsym,
939 unsigned char* view,
940 typename elfcpp::Elf_types<size>::Elf_Addr address,
941 section_size_type view_size);
942
943 // Add a new reloc argument, returning the index in the vector.
944 size_t
945 add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
946 {
947 this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
948 return this->tlsdesc_reloc_info_.size() - 1;
949 }
950
951 Output_data_plt_x86_64<size>*
952 make_data_plt(Layout* layout,
953 Output_data_got<64, false>* got,
954 Output_data_got_plt_x86_64* got_plt,
955 Output_data_space* got_irelative)
956 {
957 return this->do_make_data_plt(layout, got, got_plt, got_irelative);
958 }
959
960 Output_data_plt_x86_64<size>*
961 make_data_plt(Layout* layout,
962 Output_data_got<64, false>* got,
963 Output_data_got_plt_x86_64* got_plt,
964 Output_data_space* got_irelative,
965 unsigned int plt_count)
966 {
967 return this->do_make_data_plt(layout, got, got_plt, got_irelative,
968 plt_count);
969 }
970
971 virtual Output_data_plt_x86_64<size>*
972 do_make_data_plt(Layout* layout,
973 Output_data_got<64, false>* got,
974 Output_data_got_plt_x86_64* got_plt,
975 Output_data_space* got_irelative);
976
977 virtual Output_data_plt_x86_64<size>*
978 do_make_data_plt(Layout* layout,
979 Output_data_got<64, false>* got,
980 Output_data_got_plt_x86_64* got_plt,
981 Output_data_space* got_irelative,
982 unsigned int plt_count);
983
984 private:
985 // The class which scans relocations.
986 class Scan
987 {
988 public:
989 Scan()
990 : issued_non_pic_error_(false)
991 { }
992
993 static inline int
994 get_reference_flags(unsigned int r_type);
995
996 inline void
997 local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
998 Sized_relobj_file<size, false>* object,
999 unsigned int data_shndx,
1000 Output_section* output_section,
1001 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
1002 const elfcpp::Sym<size, false>& lsym,
1003 bool is_discarded);
1004
1005 inline void
1006 global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
1007 Sized_relobj_file<size, false>* object,
1008 unsigned int data_shndx,
1009 Output_section* output_section,
1010 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
1011 Symbol* gsym);
1012
1013 inline bool
1014 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
1015 Target_x86_64* target,
1016 Sized_relobj_file<size, false>* object,
1017 unsigned int data_shndx,
1018 Output_section* output_section,
1019 const elfcpp::Rela<size, false>& reloc,
1020 unsigned int r_type,
1021 const elfcpp::Sym<size, false>& lsym);
1022
1023 inline bool
1024 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
1025 Target_x86_64* target,
1026 Sized_relobj_file<size, false>* object,
1027 unsigned int data_shndx,
1028 Output_section* output_section,
1029 const elfcpp::Rela<size, false>& reloc,
1030 unsigned int r_type,
1031 Symbol* gsym);
1032
1033 private:
1034 static void
1035 unsupported_reloc_local(Sized_relobj_file<size, false>*,
1036 unsigned int r_type);
1037
1038 static void
1039 unsupported_reloc_global(Sized_relobj_file<size, false>*,
1040 unsigned int r_type, Symbol*);
1041
1042 void
1043 check_non_pic(Relobj*, unsigned int r_type, Symbol*);
1044
1045 inline bool
1046 possible_function_pointer_reloc(Sized_relobj_file<size, false>* src_obj,
1047 unsigned int src_indx,
1048 unsigned int r_offset,
1049 unsigned int r_type);
1050
1051 bool
1052 reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
1053 unsigned int r_type);
1054
1055 // Whether we have issued an error about a non-PIC compilation.
1056 bool issued_non_pic_error_;
1057 };
1058
1059 // The class which implements relocation.
1060 class Relocate
1061 {
1062 public:
1063 Relocate()
1064 : skip_call_tls_get_addr_(false)
1065 { }
1066
1067 ~Relocate()
1068 {
1069 if (this->skip_call_tls_get_addr_)
1070 {
1071 // FIXME: This needs to specify the location somehow.
1072 gold_error(_("missing expected TLS relocation"));
1073 }
1074 }
1075
1076 // Do a relocation. Return false if the caller should not issue
1077 // any warnings about this relocation.
1078 inline bool
1079 relocate(const Relocate_info<size, false>*, unsigned int,
1080 Target_x86_64*, Output_section*, size_t, const unsigned char*,
1081 const Sized_symbol<size>*, const Symbol_value<size>*,
1082 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
1083 section_size_type);
1084
1085 private:
1086 // Do a TLS relocation.
1087 inline void
1088 relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
1089 size_t relnum, const elfcpp::Rela<size, false>&,
1090 unsigned int r_type, const Sized_symbol<size>*,
1091 const Symbol_value<size>*,
1092 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
1093 section_size_type);
1094
1095 // Do a TLS General-Dynamic to Initial-Exec transition.
1096 inline void
1097 tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1098 const elfcpp::Rela<size, false>&, unsigned int r_type,
1099 typename elfcpp::Elf_types<size>::Elf_Addr value,
1100 unsigned char* view,
1101 typename elfcpp::Elf_types<size>::Elf_Addr,
1102 section_size_type view_size);
1103
1104 // Do a TLS General-Dynamic to Local-Exec transition.
1105 inline void
1106 tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1107 Output_segment* tls_segment,
1108 const elfcpp::Rela<size, false>&, unsigned int r_type,
1109 typename elfcpp::Elf_types<size>::Elf_Addr value,
1110 unsigned char* view,
1111 section_size_type view_size);
1112
1113 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
1114 inline void
1115 tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1116 const elfcpp::Rela<size, false>&, unsigned int r_type,
1117 typename elfcpp::Elf_types<size>::Elf_Addr value,
1118 unsigned char* view,
1119 typename elfcpp::Elf_types<size>::Elf_Addr,
1120 section_size_type view_size);
1121
1122 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1123 inline void
1124 tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1125 Output_segment* tls_segment,
1126 const elfcpp::Rela<size, false>&, unsigned int r_type,
1127 typename elfcpp::Elf_types<size>::Elf_Addr value,
1128 unsigned char* view,
1129 section_size_type view_size);
1130
1131 // Do a TLS Local-Dynamic to Local-Exec transition.
1132 inline void
1133 tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
1134 Output_segment* tls_segment,
1135 const elfcpp::Rela<size, false>&, unsigned int r_type,
1136 typename elfcpp::Elf_types<size>::Elf_Addr value,
1137 unsigned char* view,
1138 section_size_type view_size);
1139
1140 // Do a TLS Initial-Exec to Local-Exec transition.
1141 static inline void
1142 tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
1143 Output_segment* tls_segment,
1144 const elfcpp::Rela<size, false>&, unsigned int r_type,
1145 typename elfcpp::Elf_types<size>::Elf_Addr value,
1146 unsigned char* view,
1147 section_size_type view_size);
1148
1149 // This is set if we should skip the next reloc, which should be a
1150 // PLT32 reloc against ___tls_get_addr.
1151 bool skip_call_tls_get_addr_;
1152 };
1153
1154 // Check if relocation against this symbol is a candidate for
1155 // conversion from
1156 // mov foo@GOTPCREL(%rip), %reg
1157 // to lea foo(%rip), %reg.
1158 template<class View_type>
1159 static inline bool
1160 can_convert_mov_to_lea(const Symbol* gsym, unsigned int r_type,
1161 size_t r_offset, View_type* view)
1162 {
1163 gold_assert(gsym != NULL);
1164 // We cannot do the conversion unless it's one of these relocations.
1165 if (r_type != elfcpp::R_X86_64_GOTPCREL
1166 && r_type != elfcpp::R_X86_64_GOTPCRELX
1167 && r_type != elfcpp::R_X86_64_REX_GOTPCRELX)
1168 return false;
1169 // We cannot convert references to IFUNC symbols, or to symbols that
1170 // are not local to the current module.
1171 // We can't do predefined symbols because they may become undefined
1172 // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1173 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1174 || gsym->is_undefined()
1175 || gsym->is_predefined()
1176 || gsym->is_from_dynobj()
1177 || gsym->is_preemptible())
1178 return false;
1179 // If we are building a shared object and the symbol is protected, we may
1180 // need to go through the GOT.
1181 if (parameters->options().shared()
1182 && gsym->visibility() == elfcpp::STV_PROTECTED)
1183 return false;
1184 // We cannot convert references to the _DYNAMIC symbol.
1185 if (strcmp(gsym->name(), "_DYNAMIC") == 0)
1186 return false;
1187 // Check for a MOV opcode.
1188 return (*view)[r_offset - 2] == 0x8b;
1189 }
1190
1191 // Convert
1192 // callq *foo@GOTPCRELX(%rip) to
1193 // addr32 callq foo
1194 // and jmpq *foo@GOTPCRELX(%rip) to
1195 // jmpq foo
1196 // nop
1197 template<class View_type>
1198 static inline bool
1199 can_convert_callq_to_direct(const Symbol* gsym, unsigned int r_type,
1200 size_t r_offset, View_type* view)
1201 {
1202 gold_assert(gsym != NULL);
1203 // We cannot do the conversion unless it's a GOTPCRELX relocation.
1204 if (r_type != elfcpp::R_X86_64_GOTPCRELX)
1205 return false;
1206 // We cannot convert references to IFUNC symbols, or to symbols that
1207 // are not local to the current module.
1208 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1209 || gsym->is_undefined ()
1210 || gsym->is_from_dynobj()
1211 || gsym->is_preemptible())
1212 return false;
1213 // Check for a CALLQ or JMPQ opcode.
1214 return ((*view)[r_offset - 2] == 0xff
1215 && ((*view)[r_offset - 1] == 0x15
1216 || (*view)[r_offset - 1] == 0x25));
1217 }
1218
1219 // Adjust TLS relocation type based on the options and whether this
1220 // is a local symbol.
1221 static tls::Tls_optimization
1222 optimize_tls_reloc(bool is_final, int r_type);
1223
1224 // Get the GOT section, creating it if necessary.
1225 Output_data_got<64, false>*
1226 got_section(Symbol_table*, Layout*);
1227
1228 // Get the GOT PLT section.
1229 Output_data_got_plt_x86_64*
1230 got_plt_section() const
1231 {
1232 gold_assert(this->got_plt_ != NULL);
1233 return this->got_plt_;
1234 }
1235
1236 // Get the GOT section for TLSDESC entries.
1237 Output_data_got<64, false>*
1238 got_tlsdesc_section() const
1239 {
1240 gold_assert(this->got_tlsdesc_ != NULL);
1241 return this->got_tlsdesc_;
1242 }
1243
1244 // Create the PLT section.
1245 void
1246 make_plt_section(Symbol_table* symtab, Layout* layout);
1247
1248 // Create a PLT entry for a global symbol.
1249 void
1250 make_plt_entry(Symbol_table*, Layout*, Symbol*);
1251
1252 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1253 void
1254 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
1255 Sized_relobj_file<size, false>* relobj,
1256 unsigned int local_sym_index);
1257
1258 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1259 void
1260 define_tls_base_symbol(Symbol_table*, Layout*);
1261
1262 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1263 void
1264 reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
1265
1266 // Create a GOT entry for the TLS module index.
1267 unsigned int
1268 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1269 Sized_relobj_file<size, false>* object);
1270
1271 // Get the PLT section.
1272 Output_data_plt_x86_64<size>*
1273 plt_section() const
1274 {
1275 gold_assert(this->plt_ != NULL);
1276 return this->plt_;
1277 }
1278
1279 // Get the dynamic reloc section, creating it if necessary.
1280 Reloc_section*
1281 rela_dyn_section(Layout*);
1282
1283 // Get the section to use for TLSDESC relocations.
1284 Reloc_section*
1285 rela_tlsdesc_section(Layout*) const;
1286
1287 // Get the section to use for IRELATIVE relocations.
1288 Reloc_section*
1289 rela_irelative_section(Layout*);
1290
1291 // Add a potential copy relocation.
1292 void
1293 copy_reloc(Symbol_table* symtab, Layout* layout,
1294 Sized_relobj_file<size, false>* object,
1295 unsigned int shndx, Output_section* output_section,
1296 Symbol* sym, const elfcpp::Rela<size, false>& reloc)
1297 {
1298 unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1299 this->copy_relocs_.copy_reloc(symtab, layout,
1300 symtab->get_sized_symbol<size>(sym),
1301 object, shndx, output_section,
1302 r_type, reloc.get_r_offset(),
1303 reloc.get_r_addend(),
1304 this->rela_dyn_section(layout));
1305 }
1306
1307 // Record a target-specific program property in the .note.gnu.property
1308 // section.
1309 void
1310 record_gnu_property(unsigned int, unsigned int, size_t,
1311 const unsigned char*, const Object*);
1312
1313 // Merge the target-specific program properties from the current object.
1314 void
1315 merge_gnu_properties(const Object*);
1316
1317 // Finalize the target-specific program properties and add them back to
1318 // the layout.
1319 void
1320 do_finalize_gnu_properties(Layout*) const;
1321
1322 // Information about this specific target which we pass to the
1323 // general Target structure.
1324 static const Target::Target_info x86_64_info;
1325
1326 // The types of GOT entries needed for this platform.
1327 // These values are exposed to the ABI in an incremental link.
1328 // Do not renumber existing values without changing the version
1329 // number of the .gnu_incremental_inputs section.
1330 enum Got_type
1331 {
1332 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
1333 GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
1334 GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
1335 GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
1336 };
1337
1338 // This type is used as the argument to the target specific
1339 // relocation routines. The only target specific reloc is
1340 // R_X86_64_TLSDESC against a local symbol.
1341 struct Tlsdesc_info
1342 {
1343 Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1344 : object(a_object), r_sym(a_r_sym)
1345 { }
1346
1347 // The object in which the local symbol is defined.
1348 Sized_relobj_file<size, false>* object;
1349 // The local symbol index in the object.
1350 unsigned int r_sym;
1351 };
1352
1353 // The GOT section.
1354 Output_data_got<64, false>* got_;
1355 // The PLT section.
1356 Output_data_plt_x86_64<size>* plt_;
1357 // The GOT PLT section.
1358 Output_data_got_plt_x86_64* got_plt_;
1359 // The GOT section for IRELATIVE relocations.
1360 Output_data_space* got_irelative_;
1361 // The GOT section for TLSDESC relocations.
1362 Output_data_got<64, false>* got_tlsdesc_;
1363 // The _GLOBAL_OFFSET_TABLE_ symbol.
1364 Symbol* global_offset_table_;
1365 // The dynamic reloc section.
1366 Reloc_section* rela_dyn_;
1367 // The section to use for IRELATIVE relocs.
1368 Reloc_section* rela_irelative_;
1369 // Relocs saved to avoid a COPY reloc.
1370 Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1371 // Offset of the GOT entry for the TLS module index.
1372 unsigned int got_mod_index_offset_;
1373 // We handle R_X86_64_TLSDESC against a local symbol as a target
1374 // specific relocation. Here we store the object and local symbol
1375 // index for the relocation.
1376 std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1377 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1378 bool tls_base_symbol_defined_;
1379 // Target-specific program properties, from .note.gnu.property section.
1380 // Each bit represents a specific feature.
1381 uint32_t isa_1_used_;
1382 uint32_t isa_1_needed_;
1383 uint32_t feature_1_;
1384 // Target-specific properties from the current object.
1385 // These bits get ANDed into FEATURE_1_ after all properties for the object
1386 // have been processed.
1387 uint32_t object_feature_1_;
1388 // Whether we have seen our first object, for use in initializing FEATURE_1_.
1389 bool seen_first_object_;
1390 };
1391
1392 template<>
1393 const Target::Target_info Target_x86_64<64>::x86_64_info =
1394 {
1395 64, // size
1396 false, // is_big_endian
1397 elfcpp::EM_X86_64, // machine_code
1398 false, // has_make_symbol
1399 false, // has_resolve
1400 true, // has_code_fill
1401 true, // is_default_stack_executable
1402 true, // can_icf_inline_merge_sections
1403 '\0', // wrap_char
1404 "/lib/ld64.so.1", // program interpreter
1405 0x400000, // default_text_segment_address
1406 0x1000, // abi_pagesize (overridable by -z max-page-size)
1407 0x1000, // common_pagesize (overridable by -z common-page-size)
1408 false, // isolate_execinstr
1409 0, // rosegment_gap
1410 elfcpp::SHN_UNDEF, // small_common_shndx
1411 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1412 0, // small_common_section_flags
1413 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1414 NULL, // attributes_section
1415 NULL, // attributes_vendor
1416 "_start", // entry_symbol_name
1417 32, // hash_entry_size
1418 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
1419 };
1420
1421 template<>
1422 const Target::Target_info Target_x86_64<32>::x86_64_info =
1423 {
1424 32, // size
1425 false, // is_big_endian
1426 elfcpp::EM_X86_64, // machine_code
1427 false, // has_make_symbol
1428 false, // has_resolve
1429 true, // has_code_fill
1430 true, // is_default_stack_executable
1431 true, // can_icf_inline_merge_sections
1432 '\0', // wrap_char
1433 "/libx32/ldx32.so.1", // program interpreter
1434 0x400000, // default_text_segment_address
1435 0x1000, // abi_pagesize (overridable by -z max-page-size)
1436 0x1000, // common_pagesize (overridable by -z common-page-size)
1437 false, // isolate_execinstr
1438 0, // rosegment_gap
1439 elfcpp::SHN_UNDEF, // small_common_shndx
1440 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1441 0, // small_common_section_flags
1442 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1443 NULL, // attributes_section
1444 NULL, // attributes_vendor
1445 "_start", // entry_symbol_name
1446 32, // hash_entry_size
1447 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
1448 };
1449
1450 // This is called when a new output section is created. This is where
1451 // we handle the SHF_X86_64_LARGE.
1452
1453 template<int size>
1454 void
1455 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1456 {
1457 if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1458 os->set_is_large_section();
1459 }
1460
1461 // Get the GOT section, creating it if necessary.
1462
1463 template<int size>
1464 Output_data_got<64, false>*
1465 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1466 {
1467 if (this->got_ == NULL)
1468 {
1469 gold_assert(symtab != NULL && layout != NULL);
1470
1471 // When using -z now, we can treat .got.plt as a relro section.
1472 // Without -z now, it is modified after program startup by lazy
1473 // PLT relocations.
1474 bool is_got_plt_relro = parameters->options().now();
1475 Output_section_order got_order = (is_got_plt_relro
1476 ? ORDER_RELRO
1477 : ORDER_RELRO_LAST);
1478 Output_section_order got_plt_order = (is_got_plt_relro
1479 ? ORDER_RELRO
1480 : ORDER_NON_RELRO_FIRST);
1481
1482 this->got_ = new Output_data_got<64, false>();
1483
1484 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1485 (elfcpp::SHF_ALLOC
1486 | elfcpp::SHF_WRITE),
1487 this->got_, got_order, true);
1488
1489 this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1490 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1491 (elfcpp::SHF_ALLOC
1492 | elfcpp::SHF_WRITE),
1493 this->got_plt_, got_plt_order,
1494 is_got_plt_relro);
1495
1496 // The first three entries are reserved.
1497 this->got_plt_->set_current_data_size(3 * 8);
1498
1499 if (!is_got_plt_relro)
1500 {
1501 // Those bytes can go into the relro segment.
1502 layout->increase_relro(3 * 8);
1503 }
1504
1505 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1506 this->global_offset_table_ =
1507 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1508 Symbol_table::PREDEFINED,
1509 this->got_plt_,
1510 0, 0, elfcpp::STT_OBJECT,
1511 elfcpp::STB_LOCAL,
1512 elfcpp::STV_HIDDEN, 0,
1513 false, false);
1514
1515 // If there are any IRELATIVE relocations, they get GOT entries
1516 // in .got.plt after the jump slot entries.
1517 this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1518 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1519 (elfcpp::SHF_ALLOC
1520 | elfcpp::SHF_WRITE),
1521 this->got_irelative_,
1522 got_plt_order, is_got_plt_relro);
1523
1524 // If there are any TLSDESC relocations, they get GOT entries in
1525 // .got.plt after the jump slot and IRELATIVE entries.
1526 this->got_tlsdesc_ = new Output_data_got<64, false>();
1527 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1528 (elfcpp::SHF_ALLOC
1529 | elfcpp::SHF_WRITE),
1530 this->got_tlsdesc_,
1531 got_plt_order, is_got_plt_relro);
1532 }
1533
1534 return this->got_;
1535 }
1536
1537 // Get the dynamic reloc section, creating it if necessary.
1538
1539 template<int size>
1540 typename Target_x86_64<size>::Reloc_section*
1541 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1542 {
1543 if (this->rela_dyn_ == NULL)
1544 {
1545 gold_assert(layout != NULL);
1546 this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1547 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1548 elfcpp::SHF_ALLOC, this->rela_dyn_,
1549 ORDER_DYNAMIC_RELOCS, false);
1550 }
1551 return this->rela_dyn_;
1552 }
1553
1554 // Get the section to use for IRELATIVE relocs, creating it if
1555 // necessary. These go in .rela.dyn, but only after all other dynamic
1556 // relocations. They need to follow the other dynamic relocations so
1557 // that they can refer to global variables initialized by those
1558 // relocs.
1559
1560 template<int size>
1561 typename Target_x86_64<size>::Reloc_section*
1562 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1563 {
1564 if (this->rela_irelative_ == NULL)
1565 {
1566 // Make sure we have already created the dynamic reloc section.
1567 this->rela_dyn_section(layout);
1568 this->rela_irelative_ = new Reloc_section(false);
1569 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1570 elfcpp::SHF_ALLOC, this->rela_irelative_,
1571 ORDER_DYNAMIC_RELOCS, false);
1572 gold_assert(this->rela_dyn_->output_section()
1573 == this->rela_irelative_->output_section());
1574 }
1575 return this->rela_irelative_;
1576 }
1577
1578 // Record a target-specific program property from the .note.gnu.property
1579 // section.
1580 template<int size>
1581 void
1582 Target_x86_64<size>::record_gnu_property(
1583 unsigned int, unsigned int pr_type,
1584 size_t pr_datasz, const unsigned char* pr_data,
1585 const Object* object)
1586 {
1587 uint32_t val = 0;
1588
1589 switch (pr_type)
1590 {
1591 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
1592 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
1593 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
1594 if (pr_datasz != 4)
1595 {
1596 gold_warning(_("%s: corrupt .note.gnu.property section "
1597 "(pr_datasz for property %d is not 4)"),
1598 object->name().c_str(), pr_type);
1599 return;
1600 }
1601 val = elfcpp::Swap<32, false>::readval(pr_data);
1602 break;
1603 default:
1604 gold_warning(_("%s: unknown program property type 0x%x "
1605 "in .note.gnu.property section"),
1606 object->name().c_str(), pr_type);
1607 break;
1608 }
1609
1610 switch (pr_type)
1611 {
1612 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
1613 this->isa_1_used_ |= val;
1614 break;
1615 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
1616 this->isa_1_needed_ |= val;
1617 break;
1618 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
1619 // If we see multiple feature props in one object, OR them together.
1620 this->object_feature_1_ |= val;
1621 break;
1622 }
1623 }
1624
1625 // Merge the target-specific program properties from the current object.
1626 template<int size>
1627 void
1628 Target_x86_64<size>::merge_gnu_properties(const Object*)
1629 {
1630 if (this->seen_first_object_)
1631 this->feature_1_ &= this->object_feature_1_;
1632 else
1633 {
1634 this->feature_1_ = this->object_feature_1_;
1635 this->seen_first_object_ = true;
1636 }
1637 this->object_feature_1_ = 0;
1638 }
1639
1640 static inline void
1641 add_property(Layout* layout, unsigned int pr_type, uint32_t val)
1642 {
1643 unsigned char buf[4];
1644 elfcpp::Swap<32, false>::writeval(buf, val);
1645 layout->add_gnu_property(elfcpp::NT_GNU_PROPERTY_TYPE_0, pr_type, 4, buf);
1646 }
1647
1648 // Finalize the target-specific program properties and add them back to
1649 // the layout.
1650 template<int size>
1651 void
1652 Target_x86_64<size>::do_finalize_gnu_properties(Layout* layout) const
1653 {
1654 if (this->isa_1_used_ != 0)
1655 add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_USED,
1656 this->isa_1_used_);
1657 if (this->isa_1_needed_ != 0)
1658 add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED,
1659 this->isa_1_needed_);
1660 if (this->feature_1_ != 0)
1661 add_property(layout, elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND,
1662 this->feature_1_);
1663 }
1664
1665 // Write the first three reserved words of the .got.plt section.
1666 // The remainder of the section is written while writing the PLT
1667 // in Output_data_plt_i386::do_write.
1668
1669 void
1670 Output_data_got_plt_x86_64::do_write(Output_file* of)
1671 {
1672 // The first entry in the GOT is the address of the .dynamic section
1673 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1674 // We saved space for them when we created the section in
1675 // Target_x86_64::got_section.
1676 const off_t got_file_offset = this->offset();
1677 gold_assert(this->data_size() >= 24);
1678 unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1679 Output_section* dynamic = this->layout_->dynamic_section();
1680 uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1681 elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1682 memset(got_view + 8, 0, 16);
1683 of->write_output_view(got_file_offset, 24, got_view);
1684 }
1685
1686 // Initialize the PLT section.
1687
1688 template<int size>
1689 void
1690 Output_data_plt_x86_64<size>::init(Layout* layout)
1691 {
1692 this->rel_ = new Reloc_section(false);
1693 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1694 elfcpp::SHF_ALLOC, this->rel_,
1695 ORDER_DYNAMIC_PLT_RELOCS, false);
1696 }
1697
1698 template<int size>
1699 void
1700 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1701 {
1702 os->set_entsize(this->get_plt_entry_size());
1703 }
1704
1705 // Add an entry to the PLT.
1706
1707 template<int size>
1708 void
1709 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1710 Symbol* gsym)
1711 {
1712 gold_assert(!gsym->has_plt_offset());
1713
1714 unsigned int plt_index;
1715 off_t plt_offset;
1716 section_offset_type got_offset;
1717
1718 unsigned int* pcount;
1719 unsigned int offset;
1720 unsigned int reserved;
1721 Output_section_data_build* got;
1722 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1723 && gsym->can_use_relative_reloc(false))
1724 {
1725 pcount = &this->irelative_count_;
1726 offset = 0;
1727 reserved = 0;
1728 got = this->got_irelative_;
1729 }
1730 else
1731 {
1732 pcount = &this->count_;
1733 offset = 1;
1734 reserved = 3;
1735 got = this->got_plt_;
1736 }
1737
1738 if (!this->is_data_size_valid())
1739 {
1740 // Note that when setting the PLT offset for a non-IRELATIVE
1741 // entry we skip the initial reserved PLT entry.
1742 plt_index = *pcount + offset;
1743 plt_offset = plt_index * this->get_plt_entry_size();
1744
1745 ++*pcount;
1746
1747 got_offset = (plt_index - offset + reserved) * 8;
1748 gold_assert(got_offset == got->current_data_size());
1749
1750 // Every PLT entry needs a GOT entry which points back to the PLT
1751 // entry (this will be changed by the dynamic linker, normally
1752 // lazily when the function is called).
1753 got->set_current_data_size(got_offset + 8);
1754 }
1755 else
1756 {
1757 // FIXME: This is probably not correct for IRELATIVE relocs.
1758
1759 // For incremental updates, find an available slot.
1760 plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1761 this->get_plt_entry_size(), 0);
1762 if (plt_offset == -1)
1763 gold_fallback(_("out of patch space (PLT);"
1764 " relink with --incremental-full"));
1765
1766 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1767 // can be calculated from the PLT index, adjusting for the three
1768 // reserved entries at the beginning of the GOT.
1769 plt_index = plt_offset / this->get_plt_entry_size() - 1;
1770 got_offset = (plt_index - offset + reserved) * 8;
1771 }
1772
1773 gsym->set_plt_offset(plt_offset);
1774
1775 // Every PLT entry needs a reloc.
1776 this->add_relocation(symtab, layout, gsym, got_offset);
1777
1778 // Note that we don't need to save the symbol. The contents of the
1779 // PLT are independent of which symbols are used. The symbols only
1780 // appear in the relocations.
1781 }
1782
1783 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1784 // the PLT offset.
1785
1786 template<int size>
1787 unsigned int
1788 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1789 Symbol_table* symtab,
1790 Layout* layout,
1791 Sized_relobj_file<size, false>* relobj,
1792 unsigned int local_sym_index)
1793 {
1794 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1795 ++this->irelative_count_;
1796
1797 section_offset_type got_offset = this->got_irelative_->current_data_size();
1798
1799 // Every PLT entry needs a GOT entry which points back to the PLT
1800 // entry.
1801 this->got_irelative_->set_current_data_size(got_offset + 8);
1802
1803 // Every PLT entry needs a reloc.
1804 Reloc_section* rela = this->rela_irelative(symtab, layout);
1805 rela->add_symbolless_local_addend(relobj, local_sym_index,
1806 elfcpp::R_X86_64_IRELATIVE,
1807 this->got_irelative_, got_offset, 0);
1808
1809 return plt_offset;
1810 }
1811
1812 // Add the relocation for a PLT entry.
1813
1814 template<int size>
1815 void
1816 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1817 Layout* layout,
1818 Symbol* gsym,
1819 unsigned int got_offset)
1820 {
1821 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1822 && gsym->can_use_relative_reloc(false))
1823 {
1824 Reloc_section* rela = this->rela_irelative(symtab, layout);
1825 rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1826 this->got_irelative_, got_offset, 0);
1827 }
1828 else
1829 {
1830 gsym->set_needs_dynsym_entry();
1831 this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1832 got_offset, 0);
1833 }
1834 }
1835
1836 // Return where the TLSDESC relocations should go, creating it if
1837 // necessary. These follow the JUMP_SLOT relocations.
1838
1839 template<int size>
1840 typename Output_data_plt_x86_64<size>::Reloc_section*
1841 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1842 {
1843 if (this->tlsdesc_rel_ == NULL)
1844 {
1845 this->tlsdesc_rel_ = new Reloc_section(false);
1846 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1847 elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1848 ORDER_DYNAMIC_PLT_RELOCS, false);
1849 gold_assert(this->tlsdesc_rel_->output_section()
1850 == this->rel_->output_section());
1851 }
1852 return this->tlsdesc_rel_;
1853 }
1854
1855 // Return where the IRELATIVE relocations should go in the PLT. These
1856 // follow the JUMP_SLOT and the TLSDESC relocations.
1857
1858 template<int size>
1859 typename Output_data_plt_x86_64<size>::Reloc_section*
1860 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1861 Layout* layout)
1862 {
1863 if (this->irelative_rel_ == NULL)
1864 {
1865 // Make sure we have a place for the TLSDESC relocations, in
1866 // case we see any later on.
1867 this->rela_tlsdesc(layout);
1868 this->irelative_rel_ = new Reloc_section(false);
1869 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1870 elfcpp::SHF_ALLOC, this->irelative_rel_,
1871 ORDER_DYNAMIC_PLT_RELOCS, false);
1872 gold_assert(this->irelative_rel_->output_section()
1873 == this->rel_->output_section());
1874
1875 if (parameters->doing_static_link())
1876 {
1877 // A statically linked executable will only have a .rela.plt
1878 // section to hold R_X86_64_IRELATIVE relocs for
1879 // STT_GNU_IFUNC symbols. The library will use these
1880 // symbols to locate the IRELATIVE relocs at program startup
1881 // time.
1882 symtab->define_in_output_data("__rela_iplt_start", NULL,
1883 Symbol_table::PREDEFINED,
1884 this->irelative_rel_, 0, 0,
1885 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1886 elfcpp::STV_HIDDEN, 0, false, true);
1887 symtab->define_in_output_data("__rela_iplt_end", NULL,
1888 Symbol_table::PREDEFINED,
1889 this->irelative_rel_, 0, 0,
1890 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1891 elfcpp::STV_HIDDEN, 0, true, true);
1892 }
1893 }
1894 return this->irelative_rel_;
1895 }
1896
1897 // Return the PLT address to use for a global symbol.
1898
1899 template<int size>
1900 uint64_t
1901 Output_data_plt_x86_64<size>::do_address_for_global(const Symbol* gsym)
1902 {
1903 uint64_t offset = 0;
1904 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1905 && gsym->can_use_relative_reloc(false))
1906 offset = (this->count_ + 1) * this->get_plt_entry_size();
1907 return this->address() + offset + gsym->plt_offset();
1908 }
1909
1910 // Return the PLT address to use for a local symbol. These are always
1911 // IRELATIVE relocs.
1912
1913 template<int size>
1914 uint64_t
1915 Output_data_plt_x86_64<size>::do_address_for_local(const Relobj* object,
1916 unsigned int r_sym)
1917 {
1918 return (this->address()
1919 + (this->count_ + 1) * this->get_plt_entry_size()
1920 + object->local_plt_offset(r_sym));
1921 }
1922
1923 // Set the final size.
1924 template<int size>
1925 void
1926 Output_data_plt_x86_64<size>::set_final_data_size()
1927 {
1928 // Number of regular and IFUNC PLT entries, plus the first entry.
1929 unsigned int count = this->count_ + this->irelative_count_ + 1;
1930 // Count the TLSDESC entry, if present.
1931 if (this->has_tlsdesc_entry())
1932 ++count;
1933 this->set_data_size(count * this->get_plt_entry_size());
1934 }
1935
1936 // The first entry in the PLT for an executable.
1937
1938 template<int size>
1939 const unsigned char
1940 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1941 {
1942 // From AMD64 ABI Draft 0.98, page 76
1943 0xff, 0x35, // pushq contents of memory address
1944 0, 0, 0, 0, // replaced with address of .got + 8
1945 0xff, 0x25, // jmp indirect
1946 0, 0, 0, 0, // replaced with address of .got + 16
1947 0x90, 0x90, 0x90, 0x90 // noop (x4)
1948 };
1949
1950 template<int size>
1951 void
1952 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1953 unsigned char* pov,
1954 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1955 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1956 {
1957 memcpy(pov, first_plt_entry, plt_entry_size);
1958 // We do a jmp relative to the PC at the end of this instruction.
1959 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1960 (got_address + 8
1961 - (plt_address + 6)));
1962 elfcpp::Swap<32, false>::writeval(pov + 8,
1963 (got_address + 16
1964 - (plt_address + 12)));
1965 }
1966
1967 // Subsequent entries in the PLT for an executable.
1968
1969 template<int size>
1970 const unsigned char
1971 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1972 {
1973 // From AMD64 ABI Draft 0.98, page 76
1974 0xff, 0x25, // jmpq indirect
1975 0, 0, 0, 0, // replaced with address of symbol in .got
1976 0x68, // pushq immediate
1977 0, 0, 0, 0, // replaced with offset into relocation table
1978 0xe9, // jmpq relative
1979 0, 0, 0, 0 // replaced with offset to start of .plt
1980 };
1981
1982 template<int size>
1983 unsigned int
1984 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1985 unsigned char* pov,
1986 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1987 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1988 unsigned int got_offset,
1989 unsigned int plt_offset,
1990 unsigned int plt_index)
1991 {
1992 // Check PC-relative offset overflow in PLT entry.
1993 uint64_t plt_got_pcrel_offset = (got_address + got_offset
1994 - (plt_address + plt_offset + 6));
1995 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1996 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1997 plt_index + 1);
1998
1999 memcpy(pov, plt_entry, plt_entry_size);
2000 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2001 plt_got_pcrel_offset);
2002
2003 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
2004 elfcpp::Swap<32, false>::writeval(pov + 12,
2005 - (plt_offset + plt_entry_size));
2006
2007 return 6;
2008 }
2009
2010 // The reserved TLSDESC entry in the PLT for an executable.
2011
2012 template<int size>
2013 const unsigned char
2014 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
2015 {
2016 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2017 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2018 0xff, 0x35, // pushq x(%rip)
2019 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2020 0xff, 0x25, // jmpq *y(%rip)
2021 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2022 0x0f, 0x1f, // nop
2023 0x40, 0
2024 };
2025
2026 template<int size>
2027 void
2028 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
2029 unsigned char* pov,
2030 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2031 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2032 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
2033 unsigned int tlsdesc_got_offset,
2034 unsigned int plt_offset)
2035 {
2036 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2037 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2038 (got_address + 8
2039 - (plt_address + plt_offset
2040 + 6)));
2041 elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
2042 (got_base
2043 + tlsdesc_got_offset
2044 - (plt_address + plt_offset
2045 + 12)));
2046 }
2047
2048 // Return the APLT address to use for a global symbol (for -z bndplt).
2049
2050 uint64_t
2051 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol* gsym)
2052 {
2053 uint64_t offset = this->aplt_offset_;
2054 // Convert the PLT offset into an APLT offset.
2055 unsigned int plt_offset = gsym->plt_offset();
2056 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2057 && gsym->can_use_relative_reloc(false))
2058 offset += this->regular_count() * aplt_entry_size;
2059 else
2060 plt_offset -= plt_entry_size;
2061 plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
2062 return this->address() + offset + plt_offset;
2063 }
2064
2065 // Return the PLT address to use for a local symbol. These are always
2066 // IRELATIVE relocs.
2067
2068 uint64_t
2069 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj* object,
2070 unsigned int r_sym)
2071 {
2072 // Convert the PLT offset into an APLT offset.
2073 unsigned int plt_offset = ((object->local_plt_offset(r_sym) - plt_entry_size)
2074 / (plt_entry_size / aplt_entry_size));
2075 return (this->address()
2076 + this->aplt_offset_
2077 + this->regular_count() * aplt_entry_size
2078 + plt_offset);
2079 }
2080
2081 // Set the final size.
2082 void
2083 Output_data_plt_x86_64_bnd::set_final_data_size()
2084 {
2085 // Number of regular and IFUNC PLT entries.
2086 unsigned int count = this->entry_count();
2087 // Count the first entry and the TLSDESC entry, if present.
2088 unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
2089 unsigned int plt_size = (count + extra) * plt_entry_size;
2090 // Offset of the APLT.
2091 this->aplt_offset_ = plt_size;
2092 // Size of the APLT.
2093 plt_size += count * aplt_entry_size;
2094 this->set_data_size(plt_size);
2095 }
2096
2097 // The first entry in the BND PLT.
2098
2099 const unsigned char
2100 Output_data_plt_x86_64_bnd::first_plt_entry[plt_entry_size] =
2101 {
2102 // From AMD64 ABI Draft 0.98, page 76
2103 0xff, 0x35, // pushq contents of memory address
2104 0, 0, 0, 0, // replaced with address of .got + 8
2105 0xf2, 0xff, 0x25, // bnd jmp indirect
2106 0, 0, 0, 0, // replaced with address of .got + 16
2107 0x0f, 0x1f, 0x00 // nop
2108 };
2109
2110 void
2111 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
2112 unsigned char* pov,
2113 elfcpp::Elf_types<64>::Elf_Addr got_address,
2114 elfcpp::Elf_types<64>::Elf_Addr plt_address)
2115 {
2116 memcpy(pov, first_plt_entry, plt_entry_size);
2117 // We do a jmp relative to the PC at the end of this instruction.
2118 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2119 (got_address + 8
2120 - (plt_address + 6)));
2121 elfcpp::Swap<32, false>::writeval(pov + 9,
2122 (got_address + 16
2123 - (plt_address + 13)));
2124 }
2125
2126 // Subsequent entries in the BND PLT.
2127
2128 const unsigned char
2129 Output_data_plt_x86_64_bnd::plt_entry[plt_entry_size] =
2130 {
2131 // From AMD64 ABI Draft 0.99.8, page 139
2132 0x68, // pushq immediate
2133 0, 0, 0, 0, // replaced with offset into relocation table
2134 0xf2, 0xe9, // bnd jmpq relative
2135 0, 0, 0, 0, // replaced with offset to start of .plt
2136 0x0f, 0x1f, 0x44, 0, 0 // nop
2137 };
2138
2139 // Entries in the BND Additional PLT.
2140
2141 const unsigned char
2142 Output_data_plt_x86_64_bnd::aplt_entry[aplt_entry_size] =
2143 {
2144 // From AMD64 ABI Draft 0.99.8, page 139
2145 0xf2, 0xff, 0x25, // bnd jmpq indirect
2146 0, 0, 0, 0, // replaced with address of symbol in .got
2147 0x90, // nop
2148 };
2149
2150 unsigned int
2151 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
2152 unsigned char* pov,
2153 elfcpp::Elf_types<64>::Elf_Addr,
2154 elfcpp::Elf_types<64>::Elf_Addr,
2155 unsigned int,
2156 unsigned int plt_offset,
2157 unsigned int plt_index)
2158 {
2159 memcpy(pov, plt_entry, plt_entry_size);
2160 elfcpp::Swap_unaligned<32, false>::writeval(pov + 1, plt_index);
2161 elfcpp::Swap<32, false>::writeval(pov + 7, -(plt_offset + 11));
2162 return 0;
2163 }
2164
2165 void
2166 Output_data_plt_x86_64_bnd::fill_aplt_entry(
2167 unsigned char* pov,
2168 elfcpp::Elf_types<64>::Elf_Addr got_address,
2169 elfcpp::Elf_types<64>::Elf_Addr plt_address,
2170 unsigned int got_offset,
2171 unsigned int plt_offset,
2172 unsigned int plt_index)
2173 {
2174 // Check PC-relative offset overflow in PLT entry.
2175 uint64_t plt_got_pcrel_offset = (got_address + got_offset
2176 - (plt_address + plt_offset + 7));
2177 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2178 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2179 plt_index + 1);
2180
2181 memcpy(pov, aplt_entry, aplt_entry_size);
2182 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3, plt_got_pcrel_offset);
2183 }
2184
2185 // The reserved TLSDESC entry in the PLT for an executable.
2186
2187 const unsigned char
2188 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry[plt_entry_size] =
2189 {
2190 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2191 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2192 0xff, 0x35, // pushq x(%rip)
2193 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2194 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2195 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2196 0x0f, 0x1f, 0 // nop
2197 };
2198
2199 void
2200 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
2201 unsigned char* pov,
2202 elfcpp::Elf_types<64>::Elf_Addr got_address,
2203 elfcpp::Elf_types<64>::Elf_Addr plt_address,
2204 elfcpp::Elf_types<64>::Elf_Addr got_base,
2205 unsigned int tlsdesc_got_offset,
2206 unsigned int plt_offset)
2207 {
2208 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2209 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2210 (got_address + 8
2211 - (plt_address + plt_offset
2212 + 6)));
2213 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
2214 (got_base
2215 + tlsdesc_got_offset
2216 - (plt_address + plt_offset
2217 + 13)));
2218 }
2219
2220 // Return the APLT address to use for a global symbol (for IBT).
2221
2222 template<int size>
2223 uint64_t
2224 Output_data_plt_x86_64_ibt<size>::do_address_for_global(const Symbol* gsym)
2225 {
2226 uint64_t offset = this->aplt_offset_;
2227 // Convert the PLT offset into an APLT offset.
2228 unsigned int plt_offset = gsym->plt_offset();
2229 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2230 && gsym->can_use_relative_reloc(false))
2231 offset += this->regular_count() * aplt_entry_size;
2232 else
2233 plt_offset -= plt_entry_size;
2234 plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
2235 return this->address() + offset + plt_offset;
2236 }
2237
2238 // Return the PLT address to use for a local symbol. These are always
2239 // IRELATIVE relocs.
2240
2241 template<int size>
2242 uint64_t
2243 Output_data_plt_x86_64_ibt<size>::do_address_for_local(const Relobj* object,
2244 unsigned int r_sym)
2245 {
2246 // Convert the PLT offset into an APLT offset.
2247 unsigned int plt_offset = ((object->local_plt_offset(r_sym) - plt_entry_size)
2248 / (plt_entry_size / aplt_entry_size));
2249 return (this->address()
2250 + this->aplt_offset_
2251 + this->regular_count() * aplt_entry_size
2252 + plt_offset);
2253 }
2254
2255 // Set the final size.
2256
2257 template<int size>
2258 void
2259 Output_data_plt_x86_64_ibt<size>::set_final_data_size()
2260 {
2261 // Number of regular and IFUNC PLT entries.
2262 unsigned int count = this->entry_count();
2263 // Count the first entry and the TLSDESC entry, if present.
2264 unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
2265 unsigned int plt_size = (count + extra) * plt_entry_size;
2266 // Offset of the APLT.
2267 this->aplt_offset_ = plt_size;
2268 // Size of the APLT.
2269 plt_size += count * aplt_entry_size;
2270 this->set_data_size(plt_size);
2271 }
2272
2273 // The first entry in the IBT PLT.
2274
2275 template<>
2276 const unsigned char
2277 Output_data_plt_x86_64_ibt<32>::first_plt_entry[plt_entry_size] =
2278 {
2279 // MPX isn't supported for x32, so we don't need the BND prefix.
2280 // From AMD64 ABI Draft 0.98, page 76
2281 0xff, 0x35, // pushq contents of memory address
2282 0, 0, 0, 0, // replaced with address of .got + 8
2283 0xff, 0x25, // jmp indirect
2284 0, 0, 0, 0, // replaced with address of .got + 16
2285 0x90, 0x90, 0x90, 0x90 // noop (x4)
2286 };
2287
2288 template<>
2289 const unsigned char
2290 Output_data_plt_x86_64_ibt<64>::first_plt_entry[plt_entry_size] =
2291 {
2292 // Use the BND prefix so that IBT is compatible with MPX.
2293 0xff, 0x35, // pushq contents of memory address
2294 0, 0, 0, 0, // replaced with address of .got + 8
2295 0xf2, 0xff, 0x25, // bnd jmp indirect
2296 0, 0, 0, 0, // replaced with address of .got + 16
2297 0x0f, 0x1f, 0x00 // nop
2298 };
2299
2300 template<int size>
2301 void
2302 Output_data_plt_x86_64_ibt<size>::do_fill_first_plt_entry(
2303 unsigned char* pov,
2304 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2305 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
2306 {
2307 // Offsets to the addresses needing relocation.
2308 const unsigned int roff1 = 2;
2309 const unsigned int roff2 = (size == 32) ? 8 : 9;
2310
2311 memcpy(pov, first_plt_entry, plt_entry_size);
2312 // We do a jmp relative to the PC at the end of this instruction.
2313 elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1,
2314 (got_address + 8
2315 - (plt_address + roff1 + 4)));
2316 elfcpp::Swap<32, false>::writeval(pov + roff2,
2317 (got_address + 16
2318 - (plt_address + roff2 + 4)));
2319 }
2320
2321 // Subsequent entries in the IBT PLT.
2322
2323 template<>
2324 const unsigned char
2325 Output_data_plt_x86_64_ibt<32>::plt_entry[plt_entry_size] =
2326 {
2327 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2328 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2329 0x68, // pushq immediate
2330 0, 0, 0, 0, // replaced with offset into relocation table
2331 0xe9, // jmpq relative
2332 0, 0, 0, 0, // replaced with offset to start of .plt
2333 0x90, 0x90 // nop
2334 };
2335
2336 template<>
2337 const unsigned char
2338 Output_data_plt_x86_64_ibt<64>::plt_entry[plt_entry_size] =
2339 {
2340 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2341 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2342 0x68, // pushq immediate
2343 0, 0, 0, 0, // replaced with offset into relocation table
2344 0xf2, 0xe9, // bnd jmpq relative
2345 0, 0, 0, 0, // replaced with offset to start of .plt
2346 0x90 // nop
2347 };
2348
2349 // Entries in the IBT Additional PLT.
2350
2351 template<>
2352 const unsigned char
2353 Output_data_plt_x86_64_ibt<32>::aplt_entry[aplt_entry_size] =
2354 {
2355 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2356 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2357 0xff, 0x25, // jmpq indirect
2358 0, 0, 0, 0, // replaced with address of symbol in .got
2359 0x0f, 0x1f, 0x04, 0x00, // nop
2360 0x90, 0x90 // nop
2361 };
2362
2363 template<>
2364 const unsigned char
2365 Output_data_plt_x86_64_ibt<64>::aplt_entry[aplt_entry_size] =
2366 {
2367 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2368 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2369 0xf2, 0xff, 0x25, // bnd jmpq indirect
2370 0, 0, 0, 0, // replaced with address of symbol in .got
2371 0x0f, 0x1f, 0x04, 0x00, // nop
2372 0x90, // nop
2373 };
2374
2375 template<int size>
2376 unsigned int
2377 Output_data_plt_x86_64_ibt<size>::do_fill_plt_entry(
2378 unsigned char* pov,
2379 typename elfcpp::Elf_types<size>::Elf_Addr,
2380 typename elfcpp::Elf_types<size>::Elf_Addr,
2381 unsigned int,
2382 unsigned int plt_offset,
2383 unsigned int plt_index)
2384 {
2385 // Offsets to the addresses needing relocation.
2386 const unsigned int roff1 = 5;
2387 const unsigned int roff2 = (size == 32) ? 10 : 11;
2388
2389 memcpy(pov, plt_entry, plt_entry_size);
2390 elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1, plt_index);
2391 elfcpp::Swap<32, false>::writeval(pov + roff2, -(plt_offset + roff2 + 4));
2392 return 0;
2393 }
2394
2395 template<int size>
2396 void
2397 Output_data_plt_x86_64_ibt<size>::fill_aplt_entry(
2398 unsigned char* pov,
2399 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2400 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2401 unsigned int got_offset,
2402 unsigned int plt_offset,
2403 unsigned int plt_index)
2404 {
2405 // Offset to the address needing relocation.
2406 const unsigned int roff = (size == 32) ? 6 : 7;
2407
2408 // Check PC-relative offset overflow in PLT entry.
2409 uint64_t plt_got_pcrel_offset = (got_address + got_offset
2410 - (plt_address + plt_offset + roff + 4));
2411 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2412 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2413 plt_index + 1);
2414
2415 memcpy(pov, aplt_entry, aplt_entry_size);
2416 elfcpp::Swap_unaligned<32, false>::writeval(pov + roff, plt_got_pcrel_offset);
2417 }
2418
2419 // The reserved TLSDESC entry in the IBT PLT for an executable.
2420
2421 template<int size>
2422 const unsigned char
2423 Output_data_plt_x86_64_ibt<size>::tlsdesc_plt_entry[plt_entry_size] =
2424 {
2425 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2426 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2427 0xff, 0x35, // pushq x(%rip)
2428 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2429 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2430 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2431 0x0f, 0x1f, 0 // nop
2432 };
2433
2434 template<int size>
2435 void
2436 Output_data_plt_x86_64_ibt<size>::do_fill_tlsdesc_entry(
2437 unsigned char* pov,
2438 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2439 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2440 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
2441 unsigned int tlsdesc_got_offset,
2442 unsigned int plt_offset)
2443 {
2444 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2445 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2446 (got_address + 8
2447 - (plt_address + plt_offset
2448 + 6)));
2449 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
2450 (got_base
2451 + tlsdesc_got_offset
2452 - (plt_address + plt_offset
2453 + 13)));
2454 }
2455
2456 // The .eh_frame unwind information for the PLT.
2457
2458 template<int size>
2459 const unsigned char
2460 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
2461 {
2462 1, // CIE version.
2463 'z', // Augmentation: augmentation size included.
2464 'R', // Augmentation: FDE encoding included.
2465 '\0', // End of augmentation string.
2466 1, // Code alignment factor.
2467 0x78, // Data alignment factor.
2468 16, // Return address column.
2469 1, // Augmentation size.
2470 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
2471 | elfcpp::DW_EH_PE_sdata4),
2472 elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
2473 elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2474 elfcpp::DW_CFA_nop, // Align to 16 bytes.
2475 elfcpp::DW_CFA_nop
2476 };
2477
2478 template<int size>
2479 const unsigned char
2480 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2481 {
2482 0, 0, 0, 0, // Replaced with offset to .plt.
2483 0, 0, 0, 0, // Replaced with size of .plt.
2484 0, // Augmentation size.
2485 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2486 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2487 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2488 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2489 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2490 11, // Block length.
2491 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2492 elfcpp::DW_OP_breg16, 0, // Push %rip.
2493 elfcpp::DW_OP_lit15, // Push 0xf.
2494 elfcpp::DW_OP_and, // & (%rip & 0xf).
2495 elfcpp::DW_OP_lit11, // Push 0xb.
2496 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
2497 elfcpp::DW_OP_lit3, // Push 3.
2498 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
2499 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2500 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2501 elfcpp::DW_CFA_nop,
2502 elfcpp::DW_CFA_nop,
2503 elfcpp::DW_CFA_nop
2504 };
2505
2506 // The .eh_frame unwind information for the BND PLT.
2507 const unsigned char
2508 Output_data_plt_x86_64_bnd::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2509 {
2510 0, 0, 0, 0, // Replaced with offset to .plt.
2511 0, 0, 0, 0, // Replaced with size of .plt.
2512 0, // Augmentation size.
2513 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2514 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2515 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2516 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2517 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2518 11, // Block length.
2519 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2520 elfcpp::DW_OP_breg16, 0, // Push %rip.
2521 elfcpp::DW_OP_lit15, // Push 0xf.
2522 elfcpp::DW_OP_and, // & (%rip & 0xf).
2523 elfcpp::DW_OP_lit5, // Push 5.
2524 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 5)
2525 elfcpp::DW_OP_lit3, // Push 3.
2526 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 5) << 3)
2527 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
2528 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2529 elfcpp::DW_CFA_nop,
2530 elfcpp::DW_CFA_nop,
2531 elfcpp::DW_CFA_nop
2532 };
2533
2534 // The .eh_frame unwind information for the BND PLT.
2535 template<int size>
2536 const unsigned char
2537 Output_data_plt_x86_64_ibt<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2538 {
2539 0, 0, 0, 0, // Replaced with offset to .plt.
2540 0, 0, 0, 0, // Replaced with size of .plt.
2541 0, // Augmentation size.
2542 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2543 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2544 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2545 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2546 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2547 11, // Block length.
2548 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2549 elfcpp::DW_OP_breg16, 0, // Push %rip.
2550 elfcpp::DW_OP_lit15, // Push 0xf.
2551 elfcpp::DW_OP_and, // & (%rip & 0xf).
2552 elfcpp::DW_OP_lit9, // Push 9.
2553 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 9)
2554 elfcpp::DW_OP_lit3, // Push 3.
2555 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 9) << 3)
2556 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=9)<<3)+%rsp+8
2557 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2558 elfcpp::DW_CFA_nop,
2559 elfcpp::DW_CFA_nop,
2560 elfcpp::DW_CFA_nop
2561 };
2562
2563 // Write out the PLT. This uses the hand-coded instructions above,
2564 // and adjusts them as needed. This is specified by the AMD64 ABI.
2565
2566 template<int size>
2567 void
2568 Output_data_plt_x86_64<size>::do_write(Output_file* of)
2569 {
2570 const off_t offset = this->offset();
2571 const section_size_type oview_size =
2572 convert_to_section_size_type(this->data_size());
2573 unsigned char* const oview = of->get_output_view(offset, oview_size);
2574
2575 const off_t got_file_offset = this->got_plt_->offset();
2576 gold_assert(parameters->incremental_update()
2577 || (got_file_offset + this->got_plt_->data_size()
2578 == this->got_irelative_->offset()));
2579 const section_size_type got_size =
2580 convert_to_section_size_type(this->got_plt_->data_size()
2581 + this->got_irelative_->data_size());
2582 unsigned char* const got_view = of->get_output_view(got_file_offset,
2583 got_size);
2584
2585 unsigned char* pov = oview;
2586
2587 // The base address of the .plt section.
2588 typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
2589 // The base address of the .got section.
2590 typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
2591 // The base address of the PLT portion of the .got section,
2592 // which is where the GOT pointer will point, and where the
2593 // three reserved GOT entries are located.
2594 typename elfcpp::Elf_types<size>::Elf_Addr got_address
2595 = this->got_plt_->address();
2596
2597 this->fill_first_plt_entry(pov, got_address, plt_address);
2598 pov += this->get_plt_entry_size();
2599
2600 // The first three entries in the GOT are reserved, and are written
2601 // by Output_data_got_plt_x86_64::do_write.
2602 unsigned char* got_pov = got_view + 24;
2603
2604 unsigned int plt_offset = this->get_plt_entry_size();
2605 unsigned int got_offset = 24;
2606 const unsigned int count = this->count_ + this->irelative_count_;
2607 for (unsigned int plt_index = 0;
2608 plt_index < count;
2609 ++plt_index,
2610 pov += this->get_plt_entry_size(),
2611 got_pov += 8,
2612 plt_offset += this->get_plt_entry_size(),
2613 got_offset += 8)
2614 {
2615 // Set and adjust the PLT entry itself.
2616 unsigned int lazy_offset = this->fill_plt_entry(pov,
2617 got_address, plt_address,
2618 got_offset, plt_offset,
2619 plt_index);
2620
2621 // Set the entry in the GOT.
2622 elfcpp::Swap<64, false>::writeval(got_pov,
2623 plt_address + plt_offset + lazy_offset);
2624 }
2625
2626 if (this->has_tlsdesc_entry())
2627 {
2628 // Set and adjust the reserved TLSDESC PLT entry.
2629 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2630 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2631 tlsdesc_got_offset, plt_offset);
2632 pov += this->get_plt_entry_size();
2633 }
2634
2635 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2636 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2637
2638 of->write_output_view(offset, oview_size, oview);
2639 of->write_output_view(got_file_offset, got_size, got_view);
2640 }
2641
2642 // Write out the BND PLT.
2643
2644 void
2645 Output_data_plt_x86_64_bnd::do_write(Output_file* of)
2646 {
2647 const off_t offset = this->offset();
2648 const section_size_type oview_size =
2649 convert_to_section_size_type(this->data_size());
2650 unsigned char* const oview = of->get_output_view(offset, oview_size);
2651
2652 Output_data_got<64, false>* got = this->got();
2653 Output_data_got_plt_x86_64* got_plt = this->got_plt();
2654 Output_data_space* got_irelative = this->got_irelative();
2655
2656 const off_t got_file_offset = got_plt->offset();
2657 gold_assert(parameters->incremental_update()
2658 || (got_file_offset + got_plt->data_size()
2659 == got_irelative->offset()));
2660 const section_size_type got_size =
2661 convert_to_section_size_type(got_plt->data_size()
2662 + got_irelative->data_size());
2663 unsigned char* const got_view = of->get_output_view(got_file_offset,
2664 got_size);
2665
2666 unsigned char* pov = oview;
2667
2668 // The base address of the .plt section.
2669 elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2670 // The base address of the .got section.
2671 elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2672 // The base address of the PLT portion of the .got section,
2673 // which is where the GOT pointer will point, and where the
2674 // three reserved GOT entries are located.
2675 elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2676
2677 this->fill_first_plt_entry(pov, got_address, plt_address);
2678 pov += plt_entry_size;
2679
2680 // The first three entries in the GOT are reserved, and are written
2681 // by Output_data_got_plt_x86_64::do_write.
2682 unsigned char* got_pov = got_view + 24;
2683
2684 unsigned int plt_offset = plt_entry_size;
2685 unsigned int got_offset = 24;
2686 const unsigned int count = this->entry_count();
2687 for (unsigned int plt_index = 0;
2688 plt_index < count;
2689 ++plt_index,
2690 pov += plt_entry_size,
2691 got_pov += 8,
2692 plt_offset += plt_entry_size,
2693 got_offset += 8)
2694 {
2695 // Set and adjust the PLT entry itself.
2696 unsigned int lazy_offset = this->fill_plt_entry(pov,
2697 got_address, plt_address,
2698 got_offset, plt_offset,
2699 plt_index);
2700
2701 // Set the entry in the GOT.
2702 elfcpp::Swap<64, false>::writeval(got_pov,
2703 plt_address + plt_offset + lazy_offset);
2704 }
2705
2706 if (this->has_tlsdesc_entry())
2707 {
2708 // Set and adjust the reserved TLSDESC PLT entry.
2709 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2710 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2711 tlsdesc_got_offset, plt_offset);
2712 pov += this->get_plt_entry_size();
2713 }
2714
2715 // Write the additional PLT.
2716 got_offset = 24;
2717 for (unsigned int plt_index = 0;
2718 plt_index < count;
2719 ++plt_index,
2720 pov += aplt_entry_size,
2721 plt_offset += aplt_entry_size,
2722 got_offset += 8)
2723 {
2724 // Set and adjust the APLT entry.
2725 this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2726 plt_offset, plt_index);
2727 }
2728
2729 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2730 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2731
2732 of->write_output_view(offset, oview_size, oview);
2733 of->write_output_view(got_file_offset, got_size, got_view);
2734 }
2735
2736 // Write out the IBT PLT.
2737
2738 template<int size>
2739 void
2740 Output_data_plt_x86_64_ibt<size>::do_write(Output_file* of)
2741 {
2742 const off_t offset = this->offset();
2743 const section_size_type oview_size =
2744 convert_to_section_size_type(this->data_size());
2745 unsigned char* const oview = of->get_output_view(offset, oview_size);
2746
2747 Output_data_got<64, false>* got = this->got();
2748 Output_data_got_plt_x86_64* got_plt = this->got_plt();
2749 Output_data_space* got_irelative = this->got_irelative();
2750
2751 const off_t got_file_offset = got_plt->offset();
2752 gold_assert(parameters->incremental_update()
2753 || (got_file_offset + got_plt->data_size()
2754 == got_irelative->offset()));
2755 const section_size_type got_size =
2756 convert_to_section_size_type(got_plt->data_size()
2757 + got_irelative->data_size());
2758 unsigned char* const got_view = of->get_output_view(got_file_offset,
2759 got_size);
2760
2761 unsigned char* pov = oview;
2762
2763 // The base address of the .plt section.
2764 elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2765 // The base address of the .got section.
2766 elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2767 // The base address of the PLT portion of the .got section,
2768 // which is where the GOT pointer will point, and where the
2769 // three reserved GOT entries are located.
2770 elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2771
2772 this->fill_first_plt_entry(pov, got_address, plt_address);
2773 pov += plt_entry_size;
2774
2775 // The first three entries in the GOT are reserved, and are written
2776 // by Output_data_got_plt_x86_64::do_write.
2777 unsigned char* got_pov = got_view + 24;
2778
2779 unsigned int plt_offset = plt_entry_size;
2780 unsigned int got_offset = 24;
2781 const unsigned int count = this->entry_count();
2782 for (unsigned int plt_index = 0;
2783 plt_index < count;
2784 ++plt_index,
2785 pov += plt_entry_size,
2786 got_pov += 8,
2787 plt_offset += plt_entry_size,
2788 got_offset += 8)
2789 {
2790 // Set and adjust the PLT entry itself.
2791 unsigned int lazy_offset = this->fill_plt_entry(pov,
2792 got_address, plt_address,
2793 got_offset, plt_offset,
2794 plt_index);
2795
2796 // Set the entry in the GOT.
2797 elfcpp::Swap<64, false>::writeval(got_pov,
2798 plt_address + plt_offset + lazy_offset);
2799 }
2800
2801 if (this->has_tlsdesc_entry())
2802 {
2803 // Set and adjust the reserved TLSDESC PLT entry.
2804 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2805 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2806 tlsdesc_got_offset, plt_offset);
2807 pov += this->get_plt_entry_size();
2808 }
2809
2810 // Write the additional PLT.
2811 got_offset = 24;
2812 for (unsigned int plt_index = 0;
2813 plt_index < count;
2814 ++plt_index,
2815 pov += aplt_entry_size,
2816 plt_offset += aplt_entry_size,
2817 got_offset += 8)
2818 {
2819 // Set and adjust the APLT entry.
2820 this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2821 plt_offset, plt_index);
2822 }
2823
2824 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2825 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2826
2827 of->write_output_view(offset, oview_size, oview);
2828 of->write_output_view(got_file_offset, got_size, got_view);
2829 }
2830
2831 // Create the PLT section.
2832
2833 template<int size>
2834 void
2835 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
2836 {
2837 if (this->plt_ == NULL)
2838 {
2839 // Create the GOT sections first.
2840 this->got_section(symtab, layout);
2841
2842 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
2843 this->got_irelative_);
2844
2845 // Add unwind information if requested.
2846 if (parameters->options().ld_generated_unwind_info())
2847 this->plt_->add_eh_frame(layout);
2848
2849 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
2850 (elfcpp::SHF_ALLOC
2851 | elfcpp::SHF_EXECINSTR),
2852 this->plt_, ORDER_PLT, false);
2853
2854 // Make the sh_info field of .rela.plt point to .plt.
2855 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
2856 rela_plt_os->set_info_section(this->plt_->output_section());
2857 }
2858 }
2859
2860 template<>
2861 Output_data_plt_x86_64<32>*
2862 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2863 Output_data_got<64, false>* got,
2864 Output_data_got_plt_x86_64* got_plt,
2865 Output_data_space* got_irelative)
2866 {
2867 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2868 return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
2869 got_irelative);
2870 return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2871 got_irelative);
2872 }
2873
2874 template<>
2875 Output_data_plt_x86_64<64>*
2876 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2877 Output_data_got<64, false>* got,
2878 Output_data_got_plt_x86_64* got_plt,
2879 Output_data_space* got_irelative)
2880 {
2881 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2882 return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
2883 got_irelative);
2884 else if (parameters->options().bndplt())
2885 return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2886 got_irelative);
2887 else
2888 return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2889 got_irelative);
2890 }
2891
2892 template<>
2893 Output_data_plt_x86_64<32>*
2894 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2895 Output_data_got<64, false>* got,
2896 Output_data_got_plt_x86_64* got_plt,
2897 Output_data_space* got_irelative,
2898 unsigned int plt_count)
2899 {
2900 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2901 return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
2902 got_irelative, plt_count);
2903 return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2904 got_irelative, plt_count);
2905 }
2906
2907 template<>
2908 Output_data_plt_x86_64<64>*
2909 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2910 Output_data_got<64, false>* got,
2911 Output_data_got_plt_x86_64* got_plt,
2912 Output_data_space* got_irelative,
2913 unsigned int plt_count)
2914 {
2915 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2916 return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
2917 got_irelative, plt_count);
2918 else if (parameters->options().bndplt())
2919 return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2920 got_irelative, plt_count);
2921 else
2922 return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2923 got_irelative,
2924 plt_count);
2925 }
2926
2927 // Return the section for TLSDESC relocations.
2928
2929 template<int size>
2930 typename Target_x86_64<size>::Reloc_section*
2931 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
2932 {
2933 return this->plt_section()->rela_tlsdesc(layout);
2934 }
2935
2936 // Create a PLT entry for a global symbol.
2937
2938 template<int size>
2939 void
2940 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
2941 Symbol* gsym)
2942 {
2943 if (gsym->has_plt_offset())
2944 return;
2945
2946 if (this->plt_ == NULL)
2947 this->make_plt_section(symtab, layout);
2948
2949 this->plt_->add_entry(symtab, layout, gsym);
2950 }
2951
2952 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
2953
2954 template<int size>
2955 void
2956 Target_x86_64<size>::make_local_ifunc_plt_entry(
2957 Symbol_table* symtab, Layout* layout,
2958 Sized_relobj_file<size, false>* relobj,
2959 unsigned int local_sym_index)
2960 {
2961 if (relobj->local_has_plt_offset(local_sym_index))
2962 return;
2963 if (this->plt_ == NULL)
2964 this->make_plt_section(symtab, layout);
2965 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
2966 relobj,
2967 local_sym_index);
2968 relobj->set_local_plt_offset(local_sym_index, plt_offset);
2969 }
2970
2971 // Return the number of entries in the PLT.
2972
2973 template<int size>
2974 unsigned int
2975 Target_x86_64<size>::plt_entry_count() const
2976 {
2977 if (this->plt_ == NULL)
2978 return 0;
2979 return this->plt_->entry_count();
2980 }
2981
2982 // Return the offset of the first non-reserved PLT entry.
2983
2984 template<int size>
2985 unsigned int
2986 Target_x86_64<size>::first_plt_entry_offset() const
2987 {
2988 if (this->plt_ == NULL)
2989 return 0;
2990 return this->plt_->first_plt_entry_offset();
2991 }
2992
2993 // Return the size of each PLT entry.
2994
2995 template<int size>
2996 unsigned int
2997 Target_x86_64<size>::plt_entry_size() const
2998 {
2999 if (this->plt_ == NULL)
3000 return 0;
3001 return this->plt_->get_plt_entry_size();
3002 }
3003
3004 // Create the GOT and PLT sections for an incremental update.
3005
3006 template<int size>
3007 Output_data_got_base*
3008 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
3009 Layout* layout,
3010 unsigned int got_count,
3011 unsigned int plt_count)
3012 {
3013 gold_assert(this->got_ == NULL);
3014
3015 this->got_ = new Output_data_got<64, false>(got_count * 8);
3016 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3017 (elfcpp::SHF_ALLOC
3018 | elfcpp::SHF_WRITE),
3019 this->got_, ORDER_RELRO_LAST,
3020 true);
3021
3022 // Add the three reserved entries.
3023 this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
3024 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3025 (elfcpp::SHF_ALLOC
3026 | elfcpp::SHF_WRITE),
3027 this->got_plt_, ORDER_NON_RELRO_FIRST,
3028 false);
3029
3030 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3031 this->global_offset_table_ =
3032 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
3033 Symbol_table::PREDEFINED,
3034 this->got_plt_,
3035 0, 0, elfcpp::STT_OBJECT,
3036 elfcpp::STB_LOCAL,
3037 elfcpp::STV_HIDDEN, 0,
3038 false, false);
3039
3040 // If there are any TLSDESC relocations, they get GOT entries in
3041 // .got.plt after the jump slot entries.
3042 // FIXME: Get the count for TLSDESC entries.
3043 this->got_tlsdesc_ = new Output_data_got<64, false>(0);
3044 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3045 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
3046 this->got_tlsdesc_,
3047 ORDER_NON_RELRO_FIRST, false);
3048
3049 // If there are any IRELATIVE relocations, they get GOT entries in
3050 // .got.plt after the jump slot and TLSDESC entries.
3051 this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
3052 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3053 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
3054 this->got_irelative_,
3055 ORDER_NON_RELRO_FIRST, false);
3056
3057 // Create the PLT section.
3058 this->plt_ = this->make_data_plt(layout, this->got_,
3059 this->got_plt_,
3060 this->got_irelative_,
3061 plt_count);
3062
3063 // Add unwind information if requested.
3064 if (parameters->options().ld_generated_unwind_info())
3065 this->plt_->add_eh_frame(layout);
3066
3067 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
3068 elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
3069 this->plt_, ORDER_PLT, false);
3070
3071 // Make the sh_info field of .rela.plt point to .plt.
3072 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
3073 rela_plt_os->set_info_section(this->plt_->output_section());
3074
3075 // Create the rela_dyn section.
3076 this->rela_dyn_section(layout);
3077
3078 return this->got_;
3079 }
3080
3081 // Reserve a GOT entry for a local symbol, and regenerate any
3082 // necessary dynamic relocations.
3083
3084 template<int size>
3085 void
3086 Target_x86_64<size>::reserve_local_got_entry(
3087 unsigned int got_index,
3088 Sized_relobj<size, false>* obj,
3089 unsigned int r_sym,
3090 unsigned int got_type)
3091 {
3092 unsigned int got_offset = got_index * 8;
3093 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
3094
3095 this->got_->reserve_local(got_index, obj, r_sym, got_type);
3096 switch (got_type)
3097 {
3098 case GOT_TYPE_STANDARD:
3099 if (parameters->options().output_is_position_independent())
3100 rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
3101 this->got_, got_offset, 0, false);
3102 break;
3103 case GOT_TYPE_TLS_OFFSET:
3104 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
3105 this->got_, got_offset, 0);
3106 break;
3107 case GOT_TYPE_TLS_PAIR:
3108 this->got_->reserve_slot(got_index + 1);
3109 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
3110 this->got_, got_offset, 0);
3111 break;
3112 case GOT_TYPE_TLS_DESC:
3113 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
3114 // this->got_->reserve_slot(got_index + 1);
3115 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3116 // this->got_, got_offset, 0);
3117 break;
3118 default:
3119 gold_unreachable();
3120 }
3121 }
3122
3123 // Reserve a GOT entry for a global symbol, and regenerate any
3124 // necessary dynamic relocations.
3125
3126 template<int size>
3127 void
3128 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
3129 Symbol* gsym,
3130 unsigned int got_type)
3131 {
3132 unsigned int got_offset = got_index * 8;
3133 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
3134
3135 this->got_->reserve_global(got_index, gsym, got_type);
3136 switch (got_type)
3137 {
3138 case GOT_TYPE_STANDARD:
3139 if (!gsym->final_value_is_known())
3140 {
3141 if (gsym->is_from_dynobj()
3142 || gsym->is_undefined()
3143 || gsym->is_preemptible()
3144 || gsym->type() == elfcpp::STT_GNU_IFUNC)
3145 rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
3146 this->got_, got_offset, 0);
3147 else
3148 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
3149 this->got_, got_offset, 0, false);
3150 }
3151 break;
3152 case GOT_TYPE_TLS_OFFSET:
3153 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
3154 this->got_, got_offset, 0, false);
3155 break;
3156 case GOT_TYPE_TLS_PAIR:
3157 this->got_->reserve_slot(got_index + 1);
3158 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
3159 this->got_, got_offset, 0, false);
3160 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
3161 this->got_, got_offset + 8, 0, false);
3162 break;
3163 case GOT_TYPE_TLS_DESC:
3164 this->got_->reserve_slot(got_index + 1);
3165 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
3166 this->got_, got_offset, 0, false);
3167 break;
3168 default:
3169 gold_unreachable();
3170 }
3171 }
3172
3173 // Register an existing PLT entry for a global symbol.
3174
3175 template<int size>
3176 void
3177 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
3178 Layout* layout,
3179 unsigned int plt_index,
3180 Symbol* gsym)
3181 {
3182 gold_assert(this->plt_ != NULL);
3183 gold_assert(!gsym->has_plt_offset());
3184
3185 this->plt_->reserve_slot(plt_index);
3186
3187 gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
3188
3189 unsigned int got_offset = (plt_index + 3) * 8;
3190 this->plt_->add_relocation(symtab, layout, gsym, got_offset);
3191 }
3192
3193 // Force a COPY relocation for a given symbol.
3194
3195 template<int size>
3196 void
3197 Target_x86_64<size>::emit_copy_reloc(
3198 Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
3199 {
3200 this->copy_relocs_.emit_copy_reloc(symtab,
3201 symtab->get_sized_symbol<size>(sym),
3202 os,
3203 offset,
3204 this->rela_dyn_section(NULL));
3205 }
3206
3207 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
3208
3209 template<int size>
3210 void
3211 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
3212 Layout* layout)
3213 {
3214 if (this->tls_base_symbol_defined_)
3215 return;
3216
3217 Output_segment* tls_segment = layout->tls_segment();
3218 if (tls_segment != NULL)
3219 {
3220 bool is_exec = parameters->options().output_is_executable();
3221 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
3222 Symbol_table::PREDEFINED,
3223 tls_segment, 0, 0,
3224 elfcpp::STT_TLS,
3225 elfcpp::STB_LOCAL,
3226 elfcpp::STV_HIDDEN, 0,
3227 (is_exec
3228 ? Symbol::SEGMENT_END
3229 : Symbol::SEGMENT_START),
3230 true);
3231 }
3232 this->tls_base_symbol_defined_ = true;
3233 }
3234
3235 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
3236
3237 template<int size>
3238 void
3239 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
3240 Layout* layout)
3241 {
3242 if (this->plt_ == NULL)
3243 this->make_plt_section(symtab, layout);
3244
3245 if (!this->plt_->has_tlsdesc_entry())
3246 {
3247 // Allocate the TLSDESC_GOT entry.
3248 Output_data_got<64, false>* got = this->got_section(symtab, layout);
3249 unsigned int got_offset = got->add_constant(0);
3250
3251 // Allocate the TLSDESC_PLT entry.
3252 this->plt_->reserve_tlsdesc_entry(got_offset);
3253 }
3254 }
3255
3256 // Create a GOT entry for the TLS module index.
3257
3258 template<int size>
3259 unsigned int
3260 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
3261 Sized_relobj_file<size, false>* object)
3262 {
3263 if (this->got_mod_index_offset_ == -1U)
3264 {
3265 gold_assert(symtab != NULL && layout != NULL && object != NULL);
3266 Reloc_section* rela_dyn = this->rela_dyn_section(layout);
3267 Output_data_got<64, false>* got = this->got_section(symtab, layout);
3268 unsigned int got_offset = got->add_constant(0);
3269 rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
3270 got_offset, 0);
3271 got->add_constant(0);
3272 this->got_mod_index_offset_ = got_offset;
3273 }
3274 return this->got_mod_index_offset_;
3275 }
3276
3277 // Optimize the TLS relocation type based on what we know about the
3278 // symbol. IS_FINAL is true if the final address of this symbol is
3279 // known at link time.
3280
3281 template<int size>
3282 tls::Tls_optimization
3283 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
3284 {
3285 // If we are generating a shared library, then we can't do anything
3286 // in the linker.
3287 if (parameters->options().shared())
3288 return tls::TLSOPT_NONE;
3289
3290 switch (r_type)
3291 {
3292 case elfcpp::R_X86_64_TLSGD:
3293 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3294 case elfcpp::R_X86_64_TLSDESC_CALL:
3295 // These are General-Dynamic which permits fully general TLS
3296 // access. Since we know that we are generating an executable,
3297 // we can convert this to Initial-Exec. If we also know that
3298 // this is a local symbol, we can further switch to Local-Exec.
3299 if (is_final)
3300 return tls::TLSOPT_TO_LE;
3301 return tls::TLSOPT_TO_IE;
3302
3303 case elfcpp::R_X86_64_TLSLD:
3304 // This is Local-Dynamic, which refers to a local symbol in the
3305 // dynamic TLS block. Since we know that we generating an
3306 // executable, we can switch to Local-Exec.
3307 return tls::TLSOPT_TO_LE;
3308
3309 case elfcpp::R_X86_64_DTPOFF32:
3310 case elfcpp::R_X86_64_DTPOFF64:
3311 // Another Local-Dynamic reloc.
3312 return tls::TLSOPT_TO_LE;
3313
3314 case elfcpp::R_X86_64_GOTTPOFF:
3315 // These are Initial-Exec relocs which get the thread offset
3316 // from the GOT. If we know that we are linking against the
3317 // local symbol, we can switch to Local-Exec, which links the
3318 // thread offset into the instruction.
3319 if (is_final)
3320 return tls::TLSOPT_TO_LE;
3321 return tls::TLSOPT_NONE;
3322
3323 case elfcpp::R_X86_64_TPOFF32:
3324 // When we already have Local-Exec, there is nothing further we
3325 // can do.
3326 return tls::TLSOPT_NONE;
3327
3328 default:
3329 gold_unreachable();
3330 }
3331 }
3332
3333 // Get the Reference_flags for a particular relocation.
3334
3335 template<int size>
3336 int
3337 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
3338 {
3339 switch (r_type)
3340 {
3341 case elfcpp::R_X86_64_NONE:
3342 case elfcpp::R_X86_64_GNU_VTINHERIT:
3343 case elfcpp::R_X86_64_GNU_VTENTRY:
3344 case elfcpp::R_X86_64_GOTPC32:
3345 case elfcpp::R_X86_64_GOTPC64:
3346 // No symbol reference.
3347 return 0;
3348
3349 case elfcpp::R_X86_64_64:
3350 case elfcpp::R_X86_64_32:
3351 case elfcpp::R_X86_64_32S:
3352 case elfcpp::R_X86_64_16:
3353 case elfcpp::R_X86_64_8:
3354 return Symbol::ABSOLUTE_REF;
3355
3356 case elfcpp::R_X86_64_PC64:
3357 case elfcpp::R_X86_64_PC32:
3358 case elfcpp::R_X86_64_PC32_BND:
3359 case elfcpp::R_X86_64_PC16:
3360 case elfcpp::R_X86_64_PC8:
3361 case elfcpp::R_X86_64_GOTOFF64:
3362 return Symbol::RELATIVE_REF;
3363
3364 case elfcpp::R_X86_64_PLT32:
3365 case elfcpp::R_X86_64_PLT32_BND:
3366 case elfcpp::R_X86_64_PLTOFF64:
3367 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
3368
3369 case elfcpp::R_X86_64_GOT64:
3370 case elfcpp::R_X86_64_GOT32:
3371 case elfcpp::R_X86_64_GOTPCREL64:
3372 case elfcpp::R_X86_64_GOTPCREL:
3373 case elfcpp::R_X86_64_GOTPCRELX:
3374 case elfcpp::R_X86_64_REX_GOTPCRELX:
3375 case elfcpp::R_X86_64_GOTPLT64:
3376 // Absolute in GOT.
3377 return Symbol::ABSOLUTE_REF;
3378
3379 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3380 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3381 case elfcpp::R_X86_64_TLSDESC_CALL:
3382 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3383 case elfcpp::R_X86_64_DTPOFF32:
3384 case elfcpp::R_X86_64_DTPOFF64:
3385 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3386 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3387 return Symbol::TLS_REF;
3388
3389 case elfcpp::R_X86_64_COPY:
3390 case elfcpp::R_X86_64_GLOB_DAT:
3391 case elfcpp::R_X86_64_JUMP_SLOT:
3392 case elfcpp::R_X86_64_RELATIVE:
3393 case elfcpp::R_X86_64_IRELATIVE:
3394 case elfcpp::R_X86_64_TPOFF64:
3395 case elfcpp::R_X86_64_DTPMOD64:
3396 case elfcpp::R_X86_64_TLSDESC:
3397 case elfcpp::R_X86_64_SIZE32:
3398 case elfcpp::R_X86_64_SIZE64:
3399 default:
3400 // Not expected. We will give an error later.
3401 return 0;
3402 }
3403 }
3404
3405 // Report an unsupported relocation against a local symbol.
3406
3407 template<int size>
3408 void
3409 Target_x86_64<size>::Scan::unsupported_reloc_local(
3410 Sized_relobj_file<size, false>* object,
3411 unsigned int r_type)
3412 {
3413 gold_error(_("%s: unsupported reloc %u against local symbol"),
3414 object->name().c_str(), r_type);
3415 }
3416
3417 // We are about to emit a dynamic relocation of type R_TYPE. If the
3418 // dynamic linker does not support it, issue an error. The GNU linker
3419 // only issues a non-PIC error for an allocated read-only section.
3420 // Here we know the section is allocated, but we don't know that it is
3421 // read-only. But we check for all the relocation types which the
3422 // glibc dynamic linker supports, so it seems appropriate to issue an
3423 // error even if the section is not read-only. If GSYM is not NULL,
3424 // it is the symbol the relocation is against; if it is NULL, the
3425 // relocation is against a local symbol.
3426
3427 template<int size>
3428 void
3429 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
3430 Symbol* gsym)
3431 {
3432 switch (r_type)
3433 {
3434 // These are the relocation types supported by glibc for x86_64
3435 // which should always work.
3436 case elfcpp::R_X86_64_RELATIVE:
3437 case elfcpp::R_X86_64_IRELATIVE:
3438 case elfcpp::R_X86_64_GLOB_DAT:
3439 case elfcpp::R_X86_64_JUMP_SLOT:
3440 case elfcpp::R_X86_64_DTPMOD64:
3441 case elfcpp::R_X86_64_DTPOFF64:
3442 case elfcpp::R_X86_64_TPOFF64:
3443 case elfcpp::R_X86_64_64:
3444 case elfcpp::R_X86_64_COPY:
3445 return;
3446
3447 // glibc supports these reloc types, but they can overflow.
3448 case elfcpp::R_X86_64_PC32:
3449 case elfcpp::R_X86_64_PC32_BND:
3450 // A PC relative reference is OK against a local symbol or if
3451 // the symbol is defined locally.
3452 if (gsym == NULL
3453 || (!gsym->is_from_dynobj()
3454 && !gsym->is_undefined()
3455 && !gsym->is_preemptible()))
3456 return;
3457 // Fall through.
3458 case elfcpp::R_X86_64_32:
3459 // R_X86_64_32 is OK for x32.
3460 if (size == 32 && r_type == elfcpp::R_X86_64_32)
3461 return;
3462 if (this->issued_non_pic_error_)
3463 return;
3464 gold_assert(parameters->options().output_is_position_independent());
3465 if (gsym == NULL)
3466 object->error(_("requires dynamic R_X86_64_32 reloc which may "
3467 "overflow at runtime; recompile with -fPIC"));
3468 else
3469 {
3470 const char *r_name;
3471 switch (r_type)
3472 {
3473 case elfcpp::R_X86_64_32:
3474 r_name = "R_X86_64_32";
3475 break;
3476 case elfcpp::R_X86_64_PC32:
3477 r_name = "R_X86_64_PC32";
3478 break;
3479 case elfcpp::R_X86_64_PC32_BND:
3480 r_name = "R_X86_64_PC32_BND";
3481 break;
3482 default:
3483 gold_unreachable();
3484 break;
3485 }
3486 object->error(_("requires dynamic %s reloc against '%s' "
3487 "which may overflow at runtime; recompile "
3488 "with -fPIC"),
3489 r_name, gsym->name());
3490 }
3491 this->issued_non_pic_error_ = true;
3492 return;
3493
3494 default:
3495 // This prevents us from issuing more than one error per reloc
3496 // section. But we can still wind up issuing more than one
3497 // error per object file.
3498 if (this->issued_non_pic_error_)
3499 return;
3500 gold_assert(parameters->options().output_is_position_independent());
3501 object->error(_("requires unsupported dynamic reloc %u; "
3502 "recompile with -fPIC"),
3503 r_type);
3504 this->issued_non_pic_error_ = true;
3505 return;
3506
3507 case elfcpp::R_X86_64_NONE:
3508 gold_unreachable();
3509 }
3510 }
3511
3512 // Return whether we need to make a PLT entry for a relocation of the
3513 // given type against a STT_GNU_IFUNC symbol.
3514
3515 template<int size>
3516 bool
3517 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
3518 Sized_relobj_file<size, false>* object,
3519 unsigned int r_type)
3520 {
3521 int flags = Scan::get_reference_flags(r_type);
3522 if (flags & Symbol::TLS_REF)
3523 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
3524 object->name().c_str(), r_type);
3525 return flags != 0;
3526 }
3527
3528 // Scan a relocation for a local symbol.
3529
3530 template<int size>
3531 inline void
3532 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
3533 Layout* layout,
3534 Target_x86_64<size>* target,
3535 Sized_relobj_file<size, false>* object,
3536 unsigned int data_shndx,
3537 Output_section* output_section,
3538 const elfcpp::Rela<size, false>& reloc,
3539 unsigned int r_type,
3540 const elfcpp::Sym<size, false>& lsym,
3541 bool is_discarded)
3542 {
3543 if (is_discarded)
3544 return;
3545
3546 // A local STT_GNU_IFUNC symbol may require a PLT entry.
3547 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
3548 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
3549 {
3550 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3551 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
3552 }
3553
3554 switch (r_type)
3555 {
3556 case elfcpp::R_X86_64_NONE:
3557 case elfcpp::R_X86_64_GNU_VTINHERIT:
3558 case elfcpp::R_X86_64_GNU_VTENTRY:
3559 break;
3560
3561 case elfcpp::R_X86_64_64:
3562 // If building a shared library (or a position-independent
3563 // executable), we need to create a dynamic relocation for this
3564 // location. The relocation applied at link time will apply the
3565 // link-time value, so we flag the location with an
3566 // R_X86_64_RELATIVE relocation so the dynamic loader can
3567 // relocate it easily.
3568 if (parameters->options().output_is_position_independent())
3569 {
3570 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3571 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3572 rela_dyn->add_local_relative(object, r_sym,
3573 (size == 32
3574 ? elfcpp::R_X86_64_RELATIVE64
3575 : elfcpp::R_X86_64_RELATIVE),
3576 output_section, data_shndx,
3577 reloc.get_r_offset(),
3578 reloc.get_r_addend(), is_ifunc);
3579 }
3580 break;
3581
3582 case elfcpp::R_X86_64_32:
3583 case elfcpp::R_X86_64_32S:
3584 case elfcpp::R_X86_64_16:
3585 case elfcpp::R_X86_64_8:
3586 // If building a shared library (or a position-independent
3587 // executable), we need to create a dynamic relocation for this
3588 // location. We can't use an R_X86_64_RELATIVE relocation
3589 // because that is always a 64-bit relocation.
3590 if (parameters->options().output_is_position_independent())
3591 {
3592 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
3593 if (size == 32 && r_type == elfcpp::R_X86_64_32)
3594 {
3595 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3596 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3597 rela_dyn->add_local_relative(object, r_sym,
3598 elfcpp::R_X86_64_RELATIVE,
3599 output_section, data_shndx,
3600 reloc.get_r_offset(),
3601 reloc.get_r_addend(), is_ifunc);
3602 break;
3603 }
3604
3605 this->check_non_pic(object, r_type, NULL);
3606
3607 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3608 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3609 if (lsym.get_st_type() != elfcpp::STT_SECTION)
3610 rela_dyn->add_local(object, r_sym, r_type, output_section,
3611 data_shndx, reloc.get_r_offset(),
3612 reloc.get_r_addend());
3613 else
3614 {
3615 gold_assert(lsym.get_st_value() == 0);
3616 unsigned int shndx = lsym.get_st_shndx();
3617 bool is_ordinary;
3618 shndx = object->adjust_sym_shndx(r_sym, shndx,
3619 &is_ordinary);
3620 if (!is_ordinary)
3621 object->error(_("section symbol %u has bad shndx %u"),
3622 r_sym, shndx);
3623 else
3624 rela_dyn->add_local_section(object, shndx,
3625 r_type, output_section,
3626 data_shndx, reloc.get_r_offset(),
3627 reloc.get_r_addend());
3628 }
3629 }
3630 break;
3631
3632 case elfcpp::R_X86_64_PC64:
3633 case elfcpp::R_X86_64_PC32:
3634 case elfcpp::R_X86_64_PC32_BND:
3635 case elfcpp::R_X86_64_PC16:
3636 case elfcpp::R_X86_64_PC8:
3637 break;
3638
3639 case elfcpp::R_X86_64_PLT32:
3640 case elfcpp::R_X86_64_PLT32_BND:
3641 // Since we know this is a local symbol, we can handle this as a
3642 // PC32 reloc.
3643 break;
3644
3645 case elfcpp::R_X86_64_GOTPC32:
3646 case elfcpp::R_X86_64_GOTOFF64:
3647 case elfcpp::R_X86_64_GOTPC64:
3648 case elfcpp::R_X86_64_PLTOFF64:
3649 // We need a GOT section.
3650 target->got_section(symtab, layout);
3651 // For PLTOFF64, we'd normally want a PLT section, but since we
3652 // know this is a local symbol, no PLT is needed.
3653 break;
3654
3655 case elfcpp::R_X86_64_GOT64:
3656 case elfcpp::R_X86_64_GOT32:
3657 case elfcpp::R_X86_64_GOTPCREL64:
3658 case elfcpp::R_X86_64_GOTPCREL:
3659 case elfcpp::R_X86_64_GOTPCRELX:
3660 case elfcpp::R_X86_64_REX_GOTPCRELX:
3661 case elfcpp::R_X86_64_GOTPLT64:
3662 {
3663 // The symbol requires a GOT section.
3664 Output_data_got<64, false>* got = target->got_section(symtab, layout);
3665
3666 // If the relocation symbol isn't IFUNC,
3667 // and is local, then we will convert
3668 // mov foo@GOTPCREL(%rip), %reg
3669 // to lea foo(%rip), %reg.
3670 // in Relocate::relocate.
3671 if (!parameters->incremental()
3672 && (r_type == elfcpp::R_X86_64_GOTPCREL
3673 || r_type == elfcpp::R_X86_64_GOTPCRELX
3674 || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
3675 && reloc.get_r_offset() >= 2
3676 && !is_ifunc)
3677 {
3678 section_size_type stype;
3679 const unsigned char* view = object->section_contents(data_shndx,
3680 &stype, true);
3681 if (view[reloc.get_r_offset() - 2] == 0x8b)
3682 break;
3683 }
3684
3685 // The symbol requires a GOT entry.
3686 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3687
3688 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
3689 // lets function pointers compare correctly with shared
3690 // libraries. Otherwise we would need an IRELATIVE reloc.
3691 bool is_new;
3692 if (is_ifunc)
3693 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
3694 else
3695 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
3696 if (is_new)
3697 {
3698 // If we are generating a shared object, we need to add a
3699 // dynamic relocation for this symbol's GOT entry.
3700 if (parameters->options().output_is_position_independent())
3701 {
3702 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3703 // R_X86_64_RELATIVE assumes a 64-bit relocation.
3704 if (r_type != elfcpp::R_X86_64_GOT32)
3705 {
3706 unsigned int got_offset =
3707 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
3708 rela_dyn->add_local_relative(object, r_sym,
3709 elfcpp::R_X86_64_RELATIVE,
3710 got, got_offset, 0, is_ifunc);
3711 }
3712 else
3713 {
3714 this->check_non_pic(object, r_type, NULL);
3715
3716 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
3717 rela_dyn->add_local(
3718 object, r_sym, r_type, got,
3719 object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
3720 }
3721 }
3722 }
3723 // For GOTPLT64, we'd normally want a PLT section, but since
3724 // we know this is a local symbol, no PLT is needed.
3725 }
3726 break;
3727
3728 case elfcpp::R_X86_64_COPY:
3729 case elfcpp::R_X86_64_GLOB_DAT:
3730 case elfcpp::R_X86_64_JUMP_SLOT:
3731 case elfcpp::R_X86_64_RELATIVE:
3732 case elfcpp::R_X86_64_IRELATIVE:
3733 // These are outstanding tls relocs, which are unexpected when linking
3734 case elfcpp::R_X86_64_TPOFF64:
3735 case elfcpp::R_X86_64_DTPMOD64:
3736 case elfcpp::R_X86_64_TLSDESC:
3737 gold_error(_("%s: unexpected reloc %u in object file"),
3738 object->name().c_str(), r_type);
3739 break;
3740
3741 // These are initial tls relocs, which are expected when linking
3742 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3743 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3744 case elfcpp::R_X86_64_TLSDESC_CALL:
3745 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3746 case elfcpp::R_X86_64_DTPOFF32:
3747 case elfcpp::R_X86_64_DTPOFF64:
3748 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3749 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3750 {
3751 bool output_is_shared = parameters->options().shared();
3752 const tls::Tls_optimization optimized_type
3753 = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
3754 r_type);
3755 switch (r_type)
3756 {
3757 case elfcpp::R_X86_64_TLSGD: // General-dynamic
3758 if (optimized_type == tls::TLSOPT_NONE)
3759 {
3760 // Create a pair of GOT entries for the module index and
3761 // dtv-relative offset.
3762 Output_data_got<64, false>* got
3763 = target->got_section(symtab, layout);
3764 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3765 unsigned int shndx = lsym.get_st_shndx();
3766 bool is_ordinary;
3767 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
3768 if (!is_ordinary)
3769 object->error(_("local symbol %u has bad shndx %u"),
3770 r_sym, shndx);
3771 else
3772 got->add_local_pair_with_rel(object, r_sym,
3773 shndx,
3774 GOT_TYPE_TLS_PAIR,
3775 target->rela_dyn_section(layout),
3776 elfcpp::R_X86_64_DTPMOD64);
3777 }
3778 else if (optimized_type != tls::TLSOPT_TO_LE)
3779 unsupported_reloc_local(object, r_type);
3780 break;
3781
3782 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3783 target->define_tls_base_symbol(symtab, layout);
3784 if (optimized_type == tls::TLSOPT_NONE)
3785 {
3786 // Create reserved PLT and GOT entries for the resolver.
3787 target->reserve_tlsdesc_entries(symtab, layout);
3788
3789 // Generate a double GOT entry with an
3790 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
3791 // is resolved lazily, so the GOT entry needs to be in
3792 // an area in .got.plt, not .got. Call got_section to
3793 // make sure the section has been created.
3794 target->got_section(symtab, layout);
3795 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3796 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3797 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
3798 {
3799 unsigned int got_offset = got->add_constant(0);
3800 got->add_constant(0);
3801 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
3802 got_offset);
3803 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3804 // We store the arguments we need in a vector, and
3805 // use the index into the vector as the parameter
3806 // to pass to the target specific routines.
3807 uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
3808 void* arg = reinterpret_cast<void*>(intarg);
3809 rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3810 got, got_offset, 0);
3811 }
3812 }
3813 else if (optimized_type != tls::TLSOPT_TO_LE)
3814 unsupported_reloc_local(object, r_type);
3815 break;
3816
3817 case elfcpp::R_X86_64_TLSDESC_CALL:
3818 break;
3819
3820 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3821 if (optimized_type == tls::TLSOPT_NONE)
3822 {
3823 // Create a GOT entry for the module index.
3824 target->got_mod_index_entry(symtab, layout, object);
3825 }
3826 else if (optimized_type != tls::TLSOPT_TO_LE)
3827 unsupported_reloc_local(object, r_type);
3828 break;
3829
3830 case elfcpp::R_X86_64_DTPOFF32:
3831 case elfcpp::R_X86_64_DTPOFF64:
3832 break;
3833
3834 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3835 layout->set_has_static_tls();
3836 if (optimized_type == tls::TLSOPT_NONE)
3837 {
3838 // Create a GOT entry for the tp-relative offset.
3839 Output_data_got<64, false>* got
3840 = target->got_section(symtab, layout);
3841 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3842 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
3843 target->rela_dyn_section(layout),
3844 elfcpp::R_X86_64_TPOFF64);
3845 }
3846 else if (optimized_type != tls::TLSOPT_TO_LE)
3847 unsupported_reloc_local(object, r_type);
3848 break;
3849
3850 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3851 layout->set_has_static_tls();
3852 if (output_is_shared)
3853 unsupported_reloc_local(object, r_type);
3854 break;
3855
3856 default:
3857 gold_unreachable();
3858 }
3859 }
3860 break;
3861
3862 case elfcpp::R_X86_64_SIZE32:
3863 case elfcpp::R_X86_64_SIZE64:
3864 default:
3865 gold_error(_("%s: unsupported reloc %u against local symbol"),
3866 object->name().c_str(), r_type);
3867 break;
3868 }
3869 }
3870
3871
3872 // Report an unsupported relocation against a global symbol.
3873
3874 template<int size>
3875 void
3876 Target_x86_64<size>::Scan::unsupported_reloc_global(
3877 Sized_relobj_file<size, false>* object,
3878 unsigned int r_type,
3879 Symbol* gsym)
3880 {
3881 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3882 object->name().c_str(), r_type, gsym->demangled_name().c_str());
3883 }
3884
3885 // Returns true if this relocation type could be that of a function pointer.
3886 template<int size>
3887 inline bool
3888 Target_x86_64<size>::Scan::possible_function_pointer_reloc(
3889 Sized_relobj_file<size, false>* src_obj,
3890 unsigned int src_indx,
3891 unsigned int r_offset,
3892 unsigned int r_type)
3893 {
3894 switch (r_type)
3895 {
3896 case elfcpp::R_X86_64_64:
3897 case elfcpp::R_X86_64_32:
3898 case elfcpp::R_X86_64_32S:
3899 case elfcpp::R_X86_64_16:
3900 case elfcpp::R_X86_64_8:
3901 case elfcpp::R_X86_64_GOT64:
3902 case elfcpp::R_X86_64_GOT32:
3903 case elfcpp::R_X86_64_GOTPCREL64:
3904 case elfcpp::R_X86_64_GOTPCREL:
3905 case elfcpp::R_X86_64_GOTPCRELX:
3906 case elfcpp::R_X86_64_REX_GOTPCRELX:
3907 case elfcpp::R_X86_64_GOTPLT64:
3908 {
3909 return true;
3910 }
3911 case elfcpp::R_X86_64_PC32:
3912 {
3913 // This relocation may be used both for function calls and
3914 // for taking address of a function. We distinguish between
3915 // them by checking the opcodes.
3916 uint64_t sh_flags = src_obj->section_flags(src_indx);
3917 bool is_executable = (sh_flags & elfcpp::SHF_EXECINSTR) != 0;
3918 if (is_executable)
3919 {
3920 section_size_type stype;
3921 const unsigned char* view = src_obj->section_contents(src_indx,
3922 &stype,
3923 true);
3924
3925 // call
3926 if (r_offset >= 1
3927 && view[r_offset - 1] == 0xe8)
3928 return false;
3929
3930 // jmp
3931 if (r_offset >= 1
3932 && view[r_offset - 1] == 0xe9)
3933 return false;
3934
3935 // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3936 if (r_offset >= 2
3937 && view[r_offset - 2] == 0x0f
3938 && view[r_offset - 1] >= 0x80
3939 && view[r_offset - 1] <= 0x8f)
3940 return false;
3941 }
3942
3943 // Be conservative and treat all others as function pointers.
3944 return true;
3945 }
3946 }
3947 return false;
3948 }
3949
3950 // For safe ICF, scan a relocation for a local symbol to check if it
3951 // corresponds to a function pointer being taken. In that case mark
3952 // the function whose pointer was taken as not foldable.
3953
3954 template<int size>
3955 inline bool
3956 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
3957 Symbol_table* ,
3958 Layout* ,
3959 Target_x86_64<size>* ,
3960 Sized_relobj_file<size, false>* src_obj,
3961 unsigned int src_indx,
3962 Output_section* ,
3963 const elfcpp::Rela<size, false>& reloc,
3964 unsigned int r_type,
3965 const elfcpp::Sym<size, false>&)
3966 {
3967 // When building a shared library, do not fold any local symbols as it is
3968 // not possible to distinguish pointer taken versus a call by looking at
3969 // the relocation types.
3970 if (parameters->options().shared())
3971 return true;
3972
3973 return possible_function_pointer_reloc(src_obj, src_indx,
3974 reloc.get_r_offset(), r_type);
3975 }
3976
3977 // For safe ICF, scan a relocation for a global symbol to check if it
3978 // corresponds to a function pointer being taken. In that case mark
3979 // the function whose pointer was taken as not foldable.
3980
3981 template<int size>
3982 inline bool
3983 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
3984 Symbol_table*,
3985 Layout* ,
3986 Target_x86_64<size>* ,
3987 Sized_relobj_file<size, false>* src_obj,
3988 unsigned int src_indx,
3989 Output_section* ,
3990 const elfcpp::Rela<size, false>& reloc,
3991 unsigned int r_type,
3992 Symbol* gsym)
3993 {
3994 // When building a shared library, do not fold symbols whose visibility
3995 // is hidden, internal or protected.
3996 if (parameters->options().shared()
3997 && (gsym->visibility() == elfcpp::STV_INTERNAL
3998 || gsym->visibility() == elfcpp::STV_PROTECTED
3999 || gsym->visibility() == elfcpp::STV_HIDDEN))
4000 return true;
4001
4002 return possible_function_pointer_reloc(src_obj, src_indx,
4003 reloc.get_r_offset(), r_type);
4004 }
4005
4006 // Scan a relocation for a global symbol.
4007
4008 template<int size>
4009 inline void
4010 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
4011 Layout* layout,
4012 Target_x86_64<size>* target,
4013 Sized_relobj_file<size, false>* object,
4014 unsigned int data_shndx,
4015 Output_section* output_section,
4016 const elfcpp::Rela<size, false>& reloc,
4017 unsigned int r_type,
4018 Symbol* gsym)
4019 {
4020 // A STT_GNU_IFUNC symbol may require a PLT entry.
4021 if (gsym->type() == elfcpp::STT_GNU_IFUNC
4022 && this->reloc_needs_plt_for_ifunc(object, r_type))
4023 target->make_plt_entry(symtab, layout, gsym);
4024
4025 switch (r_type)
4026 {
4027 case elfcpp::R_X86_64_NONE:
4028 case elfcpp::R_X86_64_GNU_VTINHERIT:
4029 case elfcpp::R_X86_64_GNU_VTENTRY:
4030 break;
4031
4032 case elfcpp::R_X86_64_64:
4033 case elfcpp::R_X86_64_32:
4034 case elfcpp::R_X86_64_32S:
4035 case elfcpp::R_X86_64_16:
4036 case elfcpp::R_X86_64_8:
4037 {
4038 // Make a PLT entry if necessary.
4039 if (gsym->needs_plt_entry())
4040 {
4041 target->make_plt_entry(symtab, layout, gsym);
4042 // Since this is not a PC-relative relocation, we may be
4043 // taking the address of a function. In that case we need to
4044 // set the entry in the dynamic symbol table to the address of
4045 // the PLT entry.
4046 if (gsym->is_from_dynobj() && !parameters->options().shared())
4047 gsym->set_needs_dynsym_value();
4048 }
4049 // Make a dynamic relocation if necessary.
4050 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
4051 {
4052 if (!parameters->options().output_is_position_independent()
4053 && gsym->may_need_copy_reloc())
4054 {
4055 target->copy_reloc(symtab, layout, object,
4056 data_shndx, output_section, gsym, reloc);
4057 }
4058 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
4059 || (size == 32 && r_type == elfcpp::R_X86_64_32))
4060 && gsym->type() == elfcpp::STT_GNU_IFUNC
4061 && gsym->can_use_relative_reloc(false)
4062 && !gsym->is_from_dynobj()
4063 && !gsym->is_undefined()
4064 && !gsym->is_preemptible())
4065 {
4066 // Use an IRELATIVE reloc for a locally defined
4067 // STT_GNU_IFUNC symbol. This makes a function
4068 // address in a PIE executable match the address in a
4069 // shared library that it links against.
4070 Reloc_section* rela_dyn =
4071 target->rela_irelative_section(layout);
4072 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
4073 rela_dyn->add_symbolless_global_addend(gsym, r_type,
4074 output_section, object,
4075 data_shndx,
4076 reloc.get_r_offset(),
4077 reloc.get_r_addend());
4078 }
4079 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
4080 || (size == 32 && r_type == elfcpp::R_X86_64_32))
4081 && gsym->can_use_relative_reloc(false))
4082 {
4083 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4084 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
4085 output_section, object,
4086 data_shndx,
4087 reloc.get_r_offset(),
4088 reloc.get_r_addend(), false);
4089 }
4090 else
4091 {
4092 this->check_non_pic(object, r_type, gsym);
4093 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4094 rela_dyn->add_global(gsym, r_type, output_section, object,
4095 data_shndx, reloc.get_r_offset(),
4096 reloc.get_r_addend());
4097 }
4098 }
4099 }
4100 break;
4101
4102 case elfcpp::R_X86_64_PC64:
4103 case elfcpp::R_X86_64_PC32:
4104 case elfcpp::R_X86_64_PC32_BND:
4105 case elfcpp::R_X86_64_PC16:
4106 case elfcpp::R_X86_64_PC8:
4107 {
4108 // Make a PLT entry if necessary.
4109 if (gsym->needs_plt_entry())
4110 target->make_plt_entry(symtab, layout, gsym);
4111 // Make a dynamic relocation if necessary.
4112 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
4113 {
4114 if (parameters->options().output_is_executable()
4115 && gsym->may_need_copy_reloc())
4116 {
4117 target->copy_reloc(symtab, layout, object,
4118 data_shndx, output_section, gsym, reloc);
4119 }
4120 else
4121 {
4122 this->check_non_pic(object, r_type, gsym);
4123 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4124 rela_dyn->add_global(gsym, r_type, output_section, object,
4125 data_shndx, reloc.get_r_offset(),
4126 reloc.get_r_addend());
4127 }
4128 }
4129 }
4130 break;
4131
4132 case elfcpp::R_X86_64_GOT64:
4133 case elfcpp::R_X86_64_GOT32:
4134 case elfcpp::R_X86_64_GOTPCREL64:
4135 case elfcpp::R_X86_64_GOTPCREL:
4136 case elfcpp::R_X86_64_GOTPCRELX:
4137 case elfcpp::R_X86_64_REX_GOTPCRELX:
4138 case elfcpp::R_X86_64_GOTPLT64:
4139 {
4140 // The symbol requires a GOT entry.
4141 Output_data_got<64, false>* got = target->got_section(symtab, layout);
4142
4143 // If we convert this from
4144 // mov foo@GOTPCREL(%rip), %reg
4145 // to lea foo(%rip), %reg.
4146 // OR
4147 // if we convert
4148 // (callq|jmpq) *foo@GOTPCRELX(%rip) to
4149 // (callq|jmpq) foo
4150 // in Relocate::relocate, then there is nothing to do here.
4151 // We cannot make these optimizations in incremental linking mode,
4152 // because we look at the opcode to decide whether or not to make
4153 // change, and during an incremental update, the change may have
4154 // already been applied.
4155
4156 Lazy_view<size> view(object, data_shndx);
4157 size_t r_offset = reloc.get_r_offset();
4158 if (!parameters->incremental()
4159 && r_offset >= 2
4160 && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
4161 r_offset, &view))
4162 break;
4163
4164 if (!parameters->incremental()
4165 && r_offset >= 2
4166 && Target_x86_64<size>::can_convert_callq_to_direct(gsym, r_type,
4167 r_offset,
4168 &view))
4169 break;
4170
4171 if (gsym->final_value_is_known())
4172 {
4173 // For a STT_GNU_IFUNC symbol we want the PLT address.
4174 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
4175 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
4176 else
4177 got->add_global(gsym, GOT_TYPE_STANDARD);
4178 }
4179 else
4180 {
4181 // If this symbol is not fully resolved, we need to add a
4182 // dynamic relocation for it.
4183 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4184
4185 // Use a GLOB_DAT rather than a RELATIVE reloc if:
4186 //
4187 // 1) The symbol may be defined in some other module.
4188 //
4189 // 2) We are building a shared library and this is a
4190 // protected symbol; using GLOB_DAT means that the dynamic
4191 // linker can use the address of the PLT in the main
4192 // executable when appropriate so that function address
4193 // comparisons work.
4194 //
4195 // 3) This is a STT_GNU_IFUNC symbol in position dependent
4196 // code, again so that function address comparisons work.
4197 if (gsym->is_from_dynobj()
4198 || gsym->is_undefined()
4199 || gsym->is_preemptible()
4200 || (gsym->visibility() == elfcpp::STV_PROTECTED
4201 && parameters->options().shared())
4202 || (gsym->type() == elfcpp::STT_GNU_IFUNC
4203 && parameters->options().output_is_position_independent()))
4204 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
4205 elfcpp::R_X86_64_GLOB_DAT);
4206 else
4207 {
4208 // For a STT_GNU_IFUNC symbol we want to write the PLT
4209 // offset into the GOT, so that function pointer
4210 // comparisons work correctly.
4211 bool is_new;
4212 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
4213 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
4214 else
4215 {
4216 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
4217 // Tell the dynamic linker to use the PLT address
4218 // when resolving relocations.
4219 if (gsym->is_from_dynobj()
4220 && !parameters->options().shared())
4221 gsym->set_needs_dynsym_value();
4222 }
4223 if (is_new)
4224 {
4225 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
4226 rela_dyn->add_global_relative(gsym,
4227 elfcpp::R_X86_64_RELATIVE,
4228 got, got_off, 0, false);
4229 }
4230 }
4231 }
4232 }
4233 break;
4234
4235 case elfcpp::R_X86_64_PLT32:
4236 case elfcpp::R_X86_64_PLT32_BND:
4237 // If the symbol is fully resolved, this is just a PC32 reloc.
4238 // Otherwise we need a PLT entry.
4239 if (gsym->final_value_is_known())
4240 break;
4241 // If building a shared library, we can also skip the PLT entry
4242 // if the symbol is defined in the output file and is protected
4243 // or hidden.
4244 if (gsym->is_defined()
4245 && !gsym->is_from_dynobj()
4246 && !gsym->is_preemptible())
4247 break;
4248 target->make_plt_entry(symtab, layout, gsym);
4249 break;
4250
4251 case elfcpp::R_X86_64_GOTPC32:
4252 case elfcpp::R_X86_64_GOTOFF64:
4253 case elfcpp::R_X86_64_GOTPC64:
4254 case elfcpp::R_X86_64_PLTOFF64:
4255 // We need a GOT section.
4256 target->got_section(symtab, layout);
4257 // For PLTOFF64, we also need a PLT entry (but only if the
4258 // symbol is not fully resolved).
4259 if (r_type == elfcpp::R_X86_64_PLTOFF64
4260 && !gsym->final_value_is_known())
4261 target->make_plt_entry(symtab, layout, gsym);
4262 break;
4263
4264 case elfcpp::R_X86_64_COPY:
4265 case elfcpp::R_X86_64_GLOB_DAT:
4266 case elfcpp::R_X86_64_JUMP_SLOT:
4267 case elfcpp::R_X86_64_RELATIVE:
4268 case elfcpp::R_X86_64_IRELATIVE:
4269 // These are outstanding tls relocs, which are unexpected when linking
4270 case elfcpp::R_X86_64_TPOFF64:
4271 case elfcpp::R_X86_64_DTPMOD64:
4272 case elfcpp::R_X86_64_TLSDESC:
4273 gold_error(_("%s: unexpected reloc %u in object file"),
4274 object->name().c_str(), r_type);
4275 break;
4276
4277 // These are initial tls relocs, which are expected for global()
4278 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4279 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4280 case elfcpp::R_X86_64_TLSDESC_CALL:
4281 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4282 case elfcpp::R_X86_64_DTPOFF32:
4283 case elfcpp::R_X86_64_DTPOFF64:
4284 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4285 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4286 {
4287 // For the Initial-Exec model, we can treat undef symbols as final
4288 // when building an executable.
4289 const bool is_final = (gsym->final_value_is_known() ||
4290 (r_type == elfcpp::R_X86_64_GOTTPOFF &&
4291 gsym->is_undefined() &&
4292 parameters->options().output_is_executable()));
4293 const tls::Tls_optimization optimized_type
4294 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
4295 switch (r_type)
4296 {
4297 case elfcpp::R_X86_64_TLSGD: // General-dynamic
4298 if (optimized_type == tls::TLSOPT_NONE)
4299 {
4300 // Create a pair of GOT entries for the module index and
4301 // dtv-relative offset.
4302 Output_data_got<64, false>* got
4303 = target->got_section(symtab, layout);
4304 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
4305 target->rela_dyn_section(layout),
4306 elfcpp::R_X86_64_DTPMOD64,
4307 elfcpp::R_X86_64_DTPOFF64);
4308 }
4309 else if (optimized_type == tls::TLSOPT_TO_IE)
4310 {
4311 // Create a GOT entry for the tp-relative offset.
4312 Output_data_got<64, false>* got
4313 = target->got_section(symtab, layout);
4314 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4315 target->rela_dyn_section(layout),
4316 elfcpp::R_X86_64_TPOFF64);
4317 }
4318 else if (optimized_type != tls::TLSOPT_TO_LE)
4319 unsupported_reloc_global(object, r_type, gsym);
4320 break;
4321
4322 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
4323 target->define_tls_base_symbol(symtab, layout);
4324 if (optimized_type == tls::TLSOPT_NONE)
4325 {
4326 // Create reserved PLT and GOT entries for the resolver.
4327 target->reserve_tlsdesc_entries(symtab, layout);
4328
4329 // Create a double GOT entry with an R_X86_64_TLSDESC
4330 // reloc. The R_X86_64_TLSDESC reloc is resolved
4331 // lazily, so the GOT entry needs to be in an area in
4332 // .got.plt, not .got. Call got_section to make sure
4333 // the section has been created.
4334 target->got_section(symtab, layout);
4335 Output_data_got<64, false>* got = target->got_tlsdesc_section();
4336 Reloc_section* rt = target->rela_tlsdesc_section(layout);
4337 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
4338 elfcpp::R_X86_64_TLSDESC, 0);
4339 }
4340 else if (optimized_type == tls::TLSOPT_TO_IE)
4341 {
4342 // Create a GOT entry for the tp-relative offset.
4343 Output_data_got<64, false>* got
4344 = target->got_section(symtab, layout);
4345 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4346 target->rela_dyn_section(layout),
4347 elfcpp::R_X86_64_TPOFF64);
4348 }
4349 else if (optimized_type != tls::TLSOPT_TO_LE)
4350 unsupported_reloc_global(object, r_type, gsym);
4351 break;
4352
4353 case elfcpp::R_X86_64_TLSDESC_CALL:
4354 break;
4355
4356 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4357 if (optimized_type == tls::TLSOPT_NONE)
4358 {
4359 // Create a GOT entry for the module index.
4360 target->got_mod_index_entry(symtab, layout, object);
4361 }
4362 else if (optimized_type != tls::TLSOPT_TO_LE)
4363 unsupported_reloc_global(object, r_type, gsym);
4364 break;
4365
4366 case elfcpp::R_X86_64_DTPOFF32:
4367 case elfcpp::R_X86_64_DTPOFF64:
4368 break;
4369
4370 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4371 layout->set_has_static_tls();
4372 if (optimized_type == tls::TLSOPT_NONE)
4373 {
4374 // Create a GOT entry for the tp-relative offset.
4375 Output_data_got<64, false>* got
4376 = target->got_section(symtab, layout);
4377 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4378 target->rela_dyn_section(layout),
4379 elfcpp::R_X86_64_TPOFF64);
4380 }
4381 else if (optimized_type != tls::TLSOPT_TO_LE)
4382 unsupported_reloc_global(object, r_type, gsym);
4383 break;
4384
4385 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4386 layout->set_has_static_tls();
4387 if (parameters->options().shared())
4388 unsupported_reloc_global(object, r_type, gsym);
4389 break;
4390
4391 default:
4392 gold_unreachable();
4393 }
4394 }
4395 break;
4396
4397 case elfcpp::R_X86_64_SIZE32:
4398 case elfcpp::R_X86_64_SIZE64:
4399 default:
4400 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
4401 object->name().c_str(), r_type,
4402 gsym->demangled_name().c_str());
4403 break;
4404 }
4405 }
4406
4407 template<int size>
4408 void
4409 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
4410 Layout* layout,
4411 Sized_relobj_file<size, false>* object,
4412 unsigned int data_shndx,
4413 unsigned int sh_type,
4414 const unsigned char* prelocs,
4415 size_t reloc_count,
4416 Output_section* output_section,
4417 bool needs_special_offset_handling,
4418 size_t local_symbol_count,
4419 const unsigned char* plocal_symbols)
4420 {
4421 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4422 Classify_reloc;
4423
4424 if (sh_type == elfcpp::SHT_REL)
4425 {
4426 return;
4427 }
4428
4429 gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
4430 Classify_reloc>(
4431 symtab,
4432 layout,
4433 this,
4434 object,
4435 data_shndx,
4436 prelocs,
4437 reloc_count,
4438 output_section,
4439 needs_special_offset_handling,
4440 local_symbol_count,
4441 plocal_symbols);
4442
4443 }
4444 // Scan relocations for a section.
4445
4446 template<int size>
4447 void
4448 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
4449 Layout* layout,
4450 Sized_relobj_file<size, false>* object,
4451 unsigned int data_shndx,
4452 unsigned int sh_type,
4453 const unsigned char* prelocs,
4454 size_t reloc_count,
4455 Output_section* output_section,
4456 bool needs_special_offset_handling,
4457 size_t local_symbol_count,
4458 const unsigned char* plocal_symbols)
4459 {
4460 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4461 Classify_reloc;
4462
4463 if (sh_type == elfcpp::SHT_REL)
4464 {
4465 gold_error(_("%s: unsupported REL reloc section"),
4466 object->name().c_str());
4467 return;
4468 }
4469
4470 gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
4471 symtab,
4472 layout,
4473 this,
4474 object,
4475 data_shndx,
4476 prelocs,
4477 reloc_count,
4478 output_section,
4479 needs_special_offset_handling,
4480 local_symbol_count,
4481 plocal_symbols);
4482 }
4483
4484 // Finalize the sections.
4485
4486 template<int size>
4487 void
4488 Target_x86_64<size>::do_finalize_sections(
4489 Layout* layout,
4490 const Input_objects*,
4491 Symbol_table* symtab)
4492 {
4493 const Reloc_section* rel_plt = (this->plt_ == NULL
4494 ? NULL
4495 : this->plt_->rela_plt());
4496 layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
4497 this->rela_dyn_, true, false);
4498
4499 // Fill in some more dynamic tags.
4500 Output_data_dynamic* const odyn = layout->dynamic_data();
4501 if (odyn != NULL)
4502 {
4503 if (this->plt_ != NULL
4504 && this->plt_->output_section() != NULL
4505 && this->plt_->has_tlsdesc_entry())
4506 {
4507 unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
4508 unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
4509 this->got_->finalize_data_size();
4510 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
4511 this->plt_, plt_offset);
4512 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
4513 this->got_, got_offset);
4514 }
4515 }
4516
4517 // Emit any relocs we saved in an attempt to avoid generating COPY
4518 // relocs.
4519 if (this->copy_relocs_.any_saved_relocs())
4520 this->copy_relocs_.emit(this->rela_dyn_section(layout));
4521
4522 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
4523 // the .got.plt section.
4524 Symbol* sym = this->global_offset_table_;
4525 if (sym != NULL)
4526 {
4527 uint64_t data_size = this->got_plt_->current_data_size();
4528 symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
4529 }
4530
4531 if (parameters->doing_static_link()
4532 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
4533 {
4534 // If linking statically, make sure that the __rela_iplt symbols
4535 // were defined if necessary, even if we didn't create a PLT.
4536 static const Define_symbol_in_segment syms[] =
4537 {
4538 {
4539 "__rela_iplt_start", // name
4540 elfcpp::PT_LOAD, // segment_type
4541 elfcpp::PF_W, // segment_flags_set
4542 elfcpp::PF(0), // segment_flags_clear
4543 0, // value
4544 0, // size
4545 elfcpp::STT_NOTYPE, // type
4546 elfcpp::STB_GLOBAL, // binding
4547 elfcpp::STV_HIDDEN, // visibility
4548 0, // nonvis
4549 Symbol::SEGMENT_START, // offset_from_base
4550 true // only_if_ref
4551 },
4552 {
4553 "__rela_iplt_end", // name
4554 elfcpp::PT_LOAD, // segment_type
4555 elfcpp::PF_W, // segment_flags_set
4556 elfcpp::PF(0), // segment_flags_clear
4557 0, // value
4558 0, // size
4559 elfcpp::STT_NOTYPE, // type
4560 elfcpp::STB_GLOBAL, // binding
4561 elfcpp::STV_HIDDEN, // visibility
4562 0, // nonvis
4563 Symbol::SEGMENT_START, // offset_from_base
4564 true // only_if_ref
4565 }
4566 };
4567
4568 symtab->define_symbols(layout, 2, syms,
4569 layout->script_options()->saw_sections_clause());
4570 }
4571 }
4572
4573 // For x32, we need to handle PC-relative relocations using full 64-bit
4574 // arithmetic, so that we can detect relocation overflows properly.
4575 // This class overrides the pcrela32_check methods from the defaults in
4576 // Relocate_functions in reloc.h.
4577
4578 template<int size>
4579 class X86_64_relocate_functions : public Relocate_functions<size, false>
4580 {
4581 public:
4582 typedef Relocate_functions<size, false> Base;
4583
4584 // Do a simple PC relative relocation with the addend in the
4585 // relocation.
4586 static inline typename Base::Reloc_status
4587 pcrela32_check(unsigned char* view,
4588 typename elfcpp::Elf_types<64>::Elf_Addr value,
4589 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
4590 typename elfcpp::Elf_types<64>::Elf_Addr address)
4591 {
4592 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4593 Valtype* wv = reinterpret_cast<Valtype*>(view);
4594 value = value + addend - address;
4595 elfcpp::Swap<32, false>::writeval(wv, value);
4596 return (Bits<32>::has_overflow(value)
4597 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4598 }
4599
4600 // Do a simple PC relative relocation with a Symbol_value with the
4601 // addend in the relocation.
4602 static inline typename Base::Reloc_status
4603 pcrela32_check(unsigned char* view,
4604 const Sized_relobj_file<size, false>* object,
4605 const Symbol_value<size>* psymval,
4606 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
4607 typename elfcpp::Elf_types<64>::Elf_Addr address)
4608 {
4609 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4610 Valtype* wv = reinterpret_cast<Valtype*>(view);
4611 typename elfcpp::Elf_types<64>::Elf_Addr value;
4612 if (addend >= 0)
4613 value = psymval->value(object, addend);
4614 else
4615 {
4616 // For negative addends, get the symbol value without
4617 // the addend, then add the addend using 64-bit arithmetic.
4618 value = psymval->value(object, 0);
4619 value += addend;
4620 }
4621 value -= address;
4622 elfcpp::Swap<32, false>::writeval(wv, value);
4623 return (Bits<32>::has_overflow(value)
4624 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4625 }
4626 };
4627
4628 // Perform a relocation.
4629
4630 template<int size>
4631 inline bool
4632 Target_x86_64<size>::Relocate::relocate(
4633 const Relocate_info<size, false>* relinfo,
4634 unsigned int,
4635 Target_x86_64<size>* target,
4636 Output_section*,
4637 size_t relnum,
4638 const unsigned char* preloc,
4639 const Sized_symbol<size>* gsym,
4640 const Symbol_value<size>* psymval,
4641 unsigned char* view,
4642 typename elfcpp::Elf_types<size>::Elf_Addr address,
4643 section_size_type view_size)
4644 {
4645 typedef X86_64_relocate_functions<size> Reloc_funcs;
4646 const elfcpp::Rela<size, false> rela(preloc);
4647 unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
4648
4649 if (this->skip_call_tls_get_addr_)
4650 {
4651 if ((r_type != elfcpp::R_X86_64_PLT32
4652 && r_type != elfcpp::R_X86_64_GOTPCREL
4653 && r_type != elfcpp::R_X86_64_GOTPCRELX
4654 && r_type != elfcpp::R_X86_64_PLT32_BND
4655 && r_type != elfcpp::R_X86_64_PC32_BND
4656 && r_type != elfcpp::R_X86_64_PC32)
4657 || gsym == NULL
4658 || strcmp(gsym->name(), "__tls_get_addr") != 0)
4659 {
4660 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4661 _("missing expected TLS relocation"));
4662 this->skip_call_tls_get_addr_ = false;
4663 }
4664 else
4665 {
4666 this->skip_call_tls_get_addr_ = false;
4667 return false;
4668 }
4669 }
4670
4671 if (view == NULL)
4672 return true;
4673
4674 const Sized_relobj_file<size, false>* object = relinfo->object;
4675
4676 // Pick the value to use for symbols defined in the PLT.
4677 Symbol_value<size> symval;
4678 if (gsym != NULL
4679 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
4680 {
4681 symval.set_output_value(target->plt_address_for_global(gsym));
4682 psymval = &symval;
4683 }
4684 else if (gsym == NULL && psymval->is_ifunc_symbol())
4685 {
4686 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4687 if (object->local_has_plt_offset(r_sym))
4688 {
4689 symval.set_output_value(target->plt_address_for_local(object, r_sym));
4690 psymval = &symval;
4691 }
4692 }
4693
4694 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4695
4696 // Get the GOT offset if needed.
4697 // The GOT pointer points to the end of the GOT section.
4698 // We need to subtract the size of the GOT section to get
4699 // the actual offset to use in the relocation.
4700 bool have_got_offset = false;
4701 // Since the actual offset is always negative, we use signed int to
4702 // support 64-bit GOT relocations.
4703 int got_offset = 0;
4704 switch (r_type)
4705 {
4706 case elfcpp::R_X86_64_GOT32:
4707 case elfcpp::R_X86_64_GOT64:
4708 case elfcpp::R_X86_64_GOTPLT64:
4709 case elfcpp::R_X86_64_GOTPCREL64:
4710 if (gsym != NULL)
4711 {
4712 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4713 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
4714 }
4715 else
4716 {
4717 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4718 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
4719 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4720 - target->got_size());
4721 }
4722 have_got_offset = true;
4723 break;
4724
4725 default:
4726 break;
4727 }
4728
4729 typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
4730
4731 switch (r_type)
4732 {
4733 case elfcpp::R_X86_64_NONE:
4734 case elfcpp::R_X86_64_GNU_VTINHERIT:
4735 case elfcpp::R_X86_64_GNU_VTENTRY:
4736 break;
4737
4738 case elfcpp::R_X86_64_64:
4739 Reloc_funcs::rela64(view, object, psymval, addend);
4740 break;
4741
4742 case elfcpp::R_X86_64_PC64:
4743 Reloc_funcs::pcrela64(view, object, psymval, addend,
4744 address);
4745 break;
4746
4747 case elfcpp::R_X86_64_32:
4748 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4749 Reloc_funcs::CHECK_UNSIGNED);
4750 break;
4751
4752 case elfcpp::R_X86_64_32S:
4753 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4754 Reloc_funcs::CHECK_SIGNED);
4755 break;
4756
4757 case elfcpp::R_X86_64_PC32:
4758 case elfcpp::R_X86_64_PC32_BND:
4759 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4760 address);
4761 break;
4762
4763 case elfcpp::R_X86_64_16:
4764 Reloc_funcs::rela16(view, object, psymval, addend);
4765 break;
4766
4767 case elfcpp::R_X86_64_PC16:
4768 Reloc_funcs::pcrela16(view, object, psymval, addend, address);
4769 break;
4770
4771 case elfcpp::R_X86_64_8:
4772 Reloc_funcs::rela8(view, object, psymval, addend);
4773 break;
4774
4775 case elfcpp::R_X86_64_PC8:
4776 Reloc_funcs::pcrela8(view, object, psymval, addend, address);
4777 break;
4778
4779 case elfcpp::R_X86_64_PLT32:
4780 case elfcpp::R_X86_64_PLT32_BND:
4781 gold_assert(gsym == NULL
4782 || gsym->has_plt_offset()
4783 || gsym->final_value_is_known()
4784 || (gsym->is_defined()
4785 && !gsym->is_from_dynobj()
4786 && !gsym->is_preemptible()));
4787 // Note: while this code looks the same as for R_X86_64_PC32, it
4788 // behaves differently because psymval was set to point to
4789 // the PLT entry, rather than the symbol, in Scan::global().
4790 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4791 address);
4792 break;
4793
4794 case elfcpp::R_X86_64_PLTOFF64:
4795 {
4796 gold_assert(gsym);
4797 gold_assert(gsym->has_plt_offset()
4798 || gsym->final_value_is_known());
4799 typename elfcpp::Elf_types<size>::Elf_Addr got_address;
4800 // This is the address of GLOBAL_OFFSET_TABLE.
4801 got_address = target->got_plt_section()->address();
4802 Reloc_funcs::rela64(view, object, psymval, addend - got_address);
4803 }
4804 break;
4805
4806 case elfcpp::R_X86_64_GOT32:
4807 gold_assert(have_got_offset);
4808 Reloc_funcs::rela32(view, got_offset, addend);
4809 break;
4810
4811 case elfcpp::R_X86_64_GOTPC32:
4812 {
4813 gold_assert(gsym);
4814 typename elfcpp::Elf_types<size>::Elf_Addr value;
4815 value = target->got_plt_section()->address();
4816 Reloc_funcs::pcrela32_check(view, value, addend, address);
4817 }
4818 break;
4819
4820 case elfcpp::R_X86_64_GOT64:
4821 case elfcpp::R_X86_64_GOTPLT64:
4822 // R_X86_64_GOTPLT64 is obsolete and treated the same as
4823 // GOT64.
4824 gold_assert(have_got_offset);
4825 Reloc_funcs::rela64(view, got_offset, addend);
4826 break;
4827
4828 case elfcpp::R_X86_64_GOTPC64:
4829 {
4830 gold_assert(gsym);
4831 typename elfcpp::Elf_types<size>::Elf_Addr value;
4832 value = target->got_plt_section()->address();
4833 Reloc_funcs::pcrela64(view, value, addend, address);
4834 }
4835 break;
4836
4837 case elfcpp::R_X86_64_GOTOFF64:
4838 {
4839 typename elfcpp::Elf_types<size>::Elf_Addr value;
4840 value = (psymval->value(object, 0)
4841 - target->got_plt_section()->address());
4842 Reloc_funcs::rela64(view, value, addend);
4843 }
4844 break;
4845
4846 case elfcpp::R_X86_64_GOTPCREL:
4847 case elfcpp::R_X86_64_GOTPCRELX:
4848 case elfcpp::R_X86_64_REX_GOTPCRELX:
4849 {
4850 // Convert
4851 // mov foo@GOTPCREL(%rip), %reg
4852 // to lea foo(%rip), %reg.
4853 // if possible.
4854 if (!parameters->incremental()
4855 && ((gsym == NULL
4856 && rela.get_r_offset() >= 2
4857 && view[-2] == 0x8b
4858 && !psymval->is_ifunc_symbol())
4859 || (gsym != NULL
4860 && rela.get_r_offset() >= 2
4861 && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
4862 0, &view))))
4863 {
4864 view[-2] = 0x8d;
4865 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4866 }
4867 // Convert
4868 // callq *foo@GOTPCRELX(%rip) to
4869 // addr32 callq foo
4870 // and jmpq *foo@GOTPCRELX(%rip) to
4871 // jmpq foo
4872 // nop
4873 else if (!parameters->incremental()
4874 && gsym != NULL
4875 && rela.get_r_offset() >= 2
4876 && Target_x86_64<size>::can_convert_callq_to_direct(gsym,
4877 r_type,
4878 0, &view))
4879 {
4880 if (view[-1] == 0x15)
4881 {
4882 // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4883 // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
4884 view[-2] = 0x67;
4885 view[-1] = 0xe8;
4886 // Convert GOTPCRELX to 32-bit pc relative reloc.
4887 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4888 }
4889 else
4890 {
4891 // Convert jmpq *foo@GOTPCRELX(%rip) to
4892 // jmpq foo
4893 // nop
4894 // The opcode of direct jmpq is 0xe9.
4895 view[-2] = 0xe9;
4896 // The opcode of nop is 0x90.
4897 view[3] = 0x90;
4898 // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
4899 // relative and since the instruction following the jmpq is now
4900 // the nop, offset the address by 1 byte. The start of the
4901 // relocation also moves ahead by 1 byte.
4902 Reloc_funcs::pcrela32(&view[-1], object, psymval, addend,
4903 address - 1);
4904 }
4905 }
4906 else
4907 {
4908 if (gsym != NULL)
4909 {
4910 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4911 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
4912 - target->got_size());
4913 }
4914 else
4915 {
4916 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4917 gold_assert(object->local_has_got_offset(r_sym,
4918 GOT_TYPE_STANDARD));
4919 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4920 - target->got_size());
4921 }
4922 typename elfcpp::Elf_types<size>::Elf_Addr value;
4923 value = target->got_plt_section()->address() + got_offset;
4924 Reloc_funcs::pcrela32_check(view, value, addend, address);
4925 }
4926 }
4927 break;
4928
4929 case elfcpp::R_X86_64_GOTPCREL64:
4930 {
4931 gold_assert(have_got_offset);
4932 typename elfcpp::Elf_types<size>::Elf_Addr value;
4933 value = target->got_plt_section()->address() + got_offset;
4934 Reloc_funcs::pcrela64(view, value, addend, address);
4935 }
4936 break;
4937
4938 case elfcpp::R_X86_64_COPY:
4939 case elfcpp::R_X86_64_GLOB_DAT:
4940 case elfcpp::R_X86_64_JUMP_SLOT:
4941 case elfcpp::R_X86_64_RELATIVE:
4942 case elfcpp::R_X86_64_IRELATIVE:
4943 // These are outstanding tls relocs, which are unexpected when linking
4944 case elfcpp::R_X86_64_TPOFF64:
4945 case elfcpp::R_X86_64_DTPMOD64:
4946 case elfcpp::R_X86_64_TLSDESC:
4947 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4948 _("unexpected reloc %u in object file"),
4949 r_type);
4950 break;
4951
4952 // These are initial tls relocs, which are expected when linking
4953 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4954 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4955 case elfcpp::R_X86_64_TLSDESC_CALL:
4956 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4957 case elfcpp::R_X86_64_DTPOFF32:
4958 case elfcpp::R_X86_64_DTPOFF64:
4959 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4960 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4961 this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
4962 view, address, view_size);
4963 break;
4964
4965 case elfcpp::R_X86_64_SIZE32:
4966 case elfcpp::R_X86_64_SIZE64:
4967 default:
4968 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4969 _("unsupported reloc %u"),
4970 r_type);
4971 break;
4972 }
4973
4974 if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
4975 {
4976 if (gsym == NULL)
4977 {
4978 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4979 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4980 _("relocation overflow: "
4981 "reference to local symbol %u in %s"),
4982 r_sym, object->name().c_str());
4983 }
4984 else if (gsym->is_defined() && gsym->source() == Symbol::FROM_OBJECT)
4985 {
4986 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4987 _("relocation overflow: "
4988 "reference to '%s' defined in %s"),
4989 gsym->name(),
4990 gsym->object()->name().c_str());
4991 }
4992 else
4993 {
4994 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4995 _("relocation overflow: reference to '%s'"),
4996 gsym->name());
4997 }
4998 }
4999
5000 return true;
5001 }
5002
5003 // Perform a TLS relocation.
5004
5005 template<int size>
5006 inline void
5007 Target_x86_64<size>::Relocate::relocate_tls(
5008 const Relocate_info<size, false>* relinfo,
5009 Target_x86_64<size>* target,
5010 size_t relnum,
5011 const elfcpp::Rela<size, false>& rela,
5012 unsigned int r_type,
5013 const Sized_symbol<size>* gsym,
5014 const Symbol_value<size>* psymval,
5015 unsigned char* view,
5016 typename elfcpp::Elf_types<size>::Elf_Addr address,
5017 section_size_type view_size)
5018 {
5019 Output_segment* tls_segment = relinfo->layout->tls_segment();
5020
5021 const Sized_relobj_file<size, false>* object = relinfo->object;
5022 const elfcpp::Elf_Xword addend = rela.get_r_addend();
5023 elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
5024 bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
5025
5026 typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
5027
5028 const bool is_final = (gsym == NULL
5029 ? !parameters->options().shared()
5030 : gsym->final_value_is_known());
5031 tls::Tls_optimization optimized_type
5032 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
5033 switch (r_type)
5034 {
5035 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
5036 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5037 {
5038 // If this code sequence is used in a non-executable section,
5039 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
5040 // on the assumption that it's being used by itself in a debug
5041 // section. Therefore, in the unlikely event that the code
5042 // sequence appears in a non-executable section, we simply
5043 // leave it unoptimized.
5044 optimized_type = tls::TLSOPT_NONE;
5045 }
5046 if (optimized_type == tls::TLSOPT_TO_LE)
5047 {
5048 if (tls_segment == NULL)
5049 {
5050 gold_assert(parameters->errors()->error_count() > 0
5051 || issue_undefined_symbol_error(gsym));
5052 return;
5053 }
5054 this->tls_gd_to_le(relinfo, relnum, tls_segment,
5055 rela, r_type, value, view,
5056 view_size);
5057 break;
5058 }
5059 else
5060 {
5061 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
5062 ? GOT_TYPE_TLS_OFFSET
5063 : GOT_TYPE_TLS_PAIR);
5064 unsigned int got_offset;
5065 if (gsym != NULL)
5066 {
5067 gold_assert(gsym->has_got_offset(got_type));
5068 got_offset = gsym->got_offset(got_type) - target->got_size();
5069 }
5070 else
5071 {
5072 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5073 gold_assert(object->local_has_got_offset(r_sym, got_type));
5074 got_offset = (object->local_got_offset(r_sym, got_type)
5075 - target->got_size());
5076 }
5077 if (optimized_type == tls::TLSOPT_TO_IE)
5078 {
5079 value = target->got_plt_section()->address() + got_offset;
5080 this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
5081 value, view, address, view_size);
5082 break;
5083 }
5084 else if (optimized_type == tls::TLSOPT_NONE)
5085 {
5086 // Relocate the field with the offset of the pair of GOT
5087 // entries.
5088 value = target->got_plt_section()->address() + got_offset;
5089 Relocate_functions<size, false>::pcrela32(view, value, addend,
5090 address);
5091 break;
5092 }
5093 }
5094 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5095 _("unsupported reloc %u"), r_type);
5096 break;
5097
5098 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
5099 case elfcpp::R_X86_64_TLSDESC_CALL:
5100 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5101 {
5102 // See above comment for R_X86_64_TLSGD.
5103 optimized_type = tls::TLSOPT_NONE;
5104 }
5105 if (optimized_type == tls::TLSOPT_TO_LE)
5106 {
5107 if (tls_segment == NULL)
5108 {
5109 gold_assert(parameters->errors()->error_count() > 0
5110 || issue_undefined_symbol_error(gsym));
5111 return;
5112 }
5113 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
5114 rela, r_type, value, view,
5115 view_size);
5116 break;
5117 }
5118 else
5119 {
5120 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
5121 ? GOT_TYPE_TLS_OFFSET
5122 : GOT_TYPE_TLS_DESC);
5123 unsigned int got_offset = 0;
5124 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
5125 && optimized_type == tls::TLSOPT_NONE)
5126 {
5127 // We created GOT entries in the .got.tlsdesc portion of
5128 // the .got.plt section, but the offset stored in the
5129 // symbol is the offset within .got.tlsdesc.
5130 got_offset = (target->got_size()
5131 + target->got_plt_section()->data_size());
5132 }
5133 if (gsym != NULL)
5134 {
5135 gold_assert(gsym->has_got_offset(got_type));
5136 got_offset += gsym->got_offset(got_type) - target->got_size();
5137 }
5138 else
5139 {
5140 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5141 gold_assert(object->local_has_got_offset(r_sym, got_type));
5142 got_offset += (object->local_got_offset(r_sym, got_type)
5143 - target->got_size());
5144 }
5145 if (optimized_type == tls::TLSOPT_TO_IE)
5146 {
5147 value = target->got_plt_section()->address() + got_offset;
5148 this->tls_desc_gd_to_ie(relinfo, relnum,
5149 rela, r_type, value, view, address,
5150 view_size);
5151 break;
5152 }
5153 else if (optimized_type == tls::TLSOPT_NONE)
5154 {
5155 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5156 {
5157 // Relocate the field with the offset of the pair of GOT
5158 // entries.
5159 value = target->got_plt_section()->address() + got_offset;
5160 Relocate_functions<size, false>::pcrela32(view, value, addend,
5161 address);
5162 }
5163 break;
5164 }
5165 }
5166 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5167 _("unsupported reloc %u"), r_type);
5168 break;
5169
5170 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
5171 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5172 {
5173 // See above comment for R_X86_64_TLSGD.
5174 optimized_type = tls::TLSOPT_NONE;
5175 }
5176 if (optimized_type == tls::TLSOPT_TO_LE)
5177 {
5178 if (tls_segment == NULL)
5179 {
5180 gold_assert(parameters->errors()->error_count() > 0
5181 || issue_undefined_symbol_error(gsym));
5182 return;
5183 }
5184 this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
5185 value, view, view_size);
5186 break;
5187 }
5188 else if (optimized_type == tls::TLSOPT_NONE)
5189 {
5190 // Relocate the field with the offset of the GOT entry for
5191 // the module index.
5192 unsigned int got_offset;
5193 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
5194 - target->got_size());
5195 value = target->got_plt_section()->address() + got_offset;
5196 Relocate_functions<size, false>::pcrela32(view, value, addend,
5197 address);
5198 break;
5199 }
5200 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5201 _("unsupported reloc %u"), r_type);
5202 break;
5203
5204 case elfcpp::R_X86_64_DTPOFF32:
5205 // This relocation type is used in debugging information.
5206 // In that case we need to not optimize the value. If the
5207 // section is not executable, then we assume we should not
5208 // optimize this reloc. See comments above for R_X86_64_TLSGD,
5209 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
5210 // R_X86_64_TLSLD.
5211 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
5212 {
5213 if (tls_segment == NULL)
5214 {
5215 gold_assert(parameters->errors()->error_count() > 0
5216 || issue_undefined_symbol_error(gsym));
5217 return;
5218 }
5219 value -= tls_segment->memsz();
5220 }
5221 Relocate_functions<size, false>::rela32(view, value, addend);
5222 break;
5223
5224 case elfcpp::R_X86_64_DTPOFF64:
5225 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
5226 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
5227 {
5228 if (tls_segment == NULL)
5229 {
5230 gold_assert(parameters->errors()->error_count() > 0
5231 || issue_undefined_symbol_error(gsym));
5232 return;
5233 }
5234 value -= tls_segment->memsz();
5235 }
5236 Relocate_functions<size, false>::rela64(view, value, addend);
5237 break;
5238
5239 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
5240 if (gsym != NULL
5241 && gsym->is_undefined()
5242 && parameters->options().output_is_executable())
5243 {
5244 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
5245 NULL, rela,
5246 r_type, value, view,
5247 view_size);
5248 break;
5249 }
5250 else if (optimized_type == tls::TLSOPT_TO_LE)
5251 {
5252 if (tls_segment == NULL)
5253 {
5254 gold_assert(parameters->errors()->error_count() > 0
5255 || issue_undefined_symbol_error(gsym));
5256 return;
5257 }
5258 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
5259 tls_segment, rela,
5260 r_type, value, view,
5261 view_size);
5262 break;
5263 }
5264 else if (optimized_type == tls::TLSOPT_NONE)
5265 {
5266 // Relocate the field with the offset of the GOT entry for
5267 // the tp-relative offset of the symbol.
5268 unsigned int got_offset;
5269 if (gsym != NULL)
5270 {
5271 gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
5272 got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
5273 - target->got_size());
5274 }
5275 else
5276 {
5277 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5278 gold_assert(object->local_has_got_offset(r_sym,
5279 GOT_TYPE_TLS_OFFSET));
5280 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
5281 - target->got_size());
5282 }
5283 value = target->got_plt_section()->address() + got_offset;
5284 Relocate_functions<size, false>::pcrela32(view, value, addend,
5285 address);
5286 break;
5287 }
5288 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5289 _("unsupported reloc type %u"),
5290 r_type);
5291 break;
5292
5293 case elfcpp::R_X86_64_TPOFF32: // Local-exec
5294 if (tls_segment == NULL)
5295 {
5296 gold_assert(parameters->errors()->error_count() > 0
5297 || issue_undefined_symbol_error(gsym));
5298 return;
5299 }
5300 value -= tls_segment->memsz();
5301 Relocate_functions<size, false>::rela32(view, value, addend);
5302 break;
5303 }
5304 }
5305
5306 // Do a relocation in which we convert a TLS General-Dynamic to an
5307 // Initial-Exec.
5308
5309 template<int size>
5310 inline void
5311 Target_x86_64<size>::Relocate::tls_gd_to_ie(
5312 const Relocate_info<size, false>* relinfo,
5313 size_t relnum,
5314 const elfcpp::Rela<size, false>& rela,
5315 unsigned int,
5316 typename elfcpp::Elf_types<size>::Elf_Addr value,
5317 unsigned char* view,
5318 typename elfcpp::Elf_types<size>::Elf_Addr address,
5319 section_size_type view_size)
5320 {
5321 // For SIZE == 64:
5322 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5323 // .word 0x6666; rex64; call __tls_get_addr@PLT
5324 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5325 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5326 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5327 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5328 // For SIZE == 32:
5329 // leaq foo@tlsgd(%rip),%rdi;
5330 // .word 0x6666; rex64; call __tls_get_addr@PLT
5331 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5332 // leaq foo@tlsgd(%rip),%rdi;
5333 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5334 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5335
5336 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
5337 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5338 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
5339 || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
5340
5341 if (size == 64)
5342 {
5343 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5344 -4);
5345 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5346 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
5347 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5348 16);
5349 }
5350 else
5351 {
5352 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5353 -3);
5354 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5355 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
5356 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5357 15);
5358 }
5359
5360 const elfcpp::Elf_Xword addend = rela.get_r_addend();
5361 Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
5362 address);
5363
5364 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5365 // We can skip it.
5366 this->skip_call_tls_get_addr_ = true;
5367 }
5368
5369 // Do a relocation in which we convert a TLS General-Dynamic to a
5370 // Local-Exec.
5371
5372 template<int size>
5373 inline void
5374 Target_x86_64<size>::Relocate::tls_gd_to_le(
5375 const Relocate_info<size, false>* relinfo,
5376 size_t relnum,
5377 Output_segment* tls_segment,
5378 const elfcpp::Rela<size, false>& rela,
5379 unsigned int,
5380 typename elfcpp::Elf_types<size>::Elf_Addr value,
5381 unsigned char* view,
5382 section_size_type view_size)
5383 {
5384 // For SIZE == 64:
5385 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5386 // .word 0x6666; rex64; call __tls_get_addr@PLT
5387 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5388 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5389 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5390 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5391 // For SIZE == 32:
5392 // leaq foo@tlsgd(%rip),%rdi;
5393 // .word 0x6666; rex64; call __tls_get_addr@PLT
5394 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5395 // leaq foo@tlsgd(%rip),%rdi;
5396 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5397 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5398
5399 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
5400 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5401 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
5402 || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
5403
5404 if (size == 64)
5405 {
5406 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5407 -4);
5408 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5409 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
5410 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5411 16);
5412 }
5413 else
5414 {
5415 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5416 -3);
5417 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5418 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
5419
5420 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5421 15);
5422 }
5423
5424 value -= tls_segment->memsz();
5425 Relocate_functions<size, false>::rela32(view + 8, value, 0);
5426
5427 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5428 // We can skip it.
5429 this->skip_call_tls_get_addr_ = true;
5430 }
5431
5432 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
5433
5434 template<int size>
5435 inline void
5436 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
5437 const Relocate_info<size, false>* relinfo,
5438 size_t relnum,
5439 const elfcpp::Rela<size, false>& rela,
5440 unsigned int r_type,
5441 typename elfcpp::Elf_types<size>::Elf_Addr value,
5442 unsigned char* view,
5443 typename elfcpp::Elf_types<size>::Elf_Addr address,
5444 section_size_type view_size)
5445 {
5446 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5447 {
5448 // leaq foo@tlsdesc(%rip), %rax
5449 // ==> movq foo@gottpoff(%rip), %rax
5450 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5451 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5452 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5453 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
5454 view[-2] = 0x8b;
5455 const elfcpp::Elf_Xword addend = rela.get_r_addend();
5456 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
5457 }
5458 else
5459 {
5460 // call *foo@tlscall(%rax)
5461 // ==> nop; nop
5462 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
5463 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
5464 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5465 view[0] == 0xff && view[1] == 0x10);
5466 view[0] = 0x66;
5467 view[1] = 0x90;
5468 }
5469 }
5470
5471 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
5472
5473 template<int size>
5474 inline void
5475 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
5476 const Relocate_info<size, false>* relinfo,
5477 size_t relnum,
5478 Output_segment* tls_segment,
5479 const elfcpp::Rela<size, false>& rela,
5480 unsigned int r_type,
5481 typename elfcpp::Elf_types<size>::Elf_Addr value,
5482 unsigned char* view,
5483 section_size_type view_size)
5484 {
5485 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5486 {
5487 // leaq foo@tlsdesc(%rip), %rax
5488 // ==> movq foo@tpoff, %rax
5489 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5490 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5491 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5492 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
5493 view[-2] = 0xc7;
5494 view[-1] = 0xc0;
5495 value -= tls_segment->memsz();
5496 Relocate_functions<size, false>::rela32(view, value, 0);
5497 }
5498 else
5499 {
5500 // call *foo@tlscall(%rax)
5501 // ==> nop; nop
5502 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
5503 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
5504 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5505 view[0] == 0xff && view[1] == 0x10);
5506 view[0] = 0x66;
5507 view[1] = 0x90;
5508 }
5509 }
5510
5511 template<int size>
5512 inline void
5513 Target_x86_64<size>::Relocate::tls_ld_to_le(
5514 const Relocate_info<size, false>* relinfo,
5515 size_t relnum,
5516 Output_segment*,
5517 const elfcpp::Rela<size, false>& rela,
5518 unsigned int,
5519 typename elfcpp::Elf_types<size>::Elf_Addr,
5520 unsigned char* view,
5521 section_size_type view_size)
5522 {
5523 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
5524 // For SIZE == 64:
5525 // ... leq foo@dtpoff(%rax),%reg
5526 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5527 // For SIZE == 32:
5528 // ... leq foo@dtpoff(%rax),%reg
5529 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5530 // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
5531 // For SIZE == 64:
5532 // ... leq foo@dtpoff(%rax),%reg
5533 // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5534 // For SIZE == 32:
5535 // ... leq foo@dtpoff(%rax),%reg
5536 // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5537
5538 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5539 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
5540
5541 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5542 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
5543
5544 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5545 view[4] == 0xe8 || view[4] == 0xff);
5546
5547 if (view[4] == 0xe8)
5548 {
5549 if (size == 64)
5550 memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
5551 else
5552 memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
5553 }
5554 else
5555 {
5556 if (size == 64)
5557 memcpy(view - 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
5558 13);
5559 else
5560 memcpy(view - 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
5561 13);
5562 }
5563
5564 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5565 // We can skip it.
5566 this->skip_call_tls_get_addr_ = true;
5567 }
5568
5569 // Do a relocation in which we convert a TLS Initial-Exec to a
5570 // Local-Exec.
5571
5572 template<int size>
5573 inline void
5574 Target_x86_64<size>::Relocate::tls_ie_to_le(
5575 const Relocate_info<size, false>* relinfo,
5576 size_t relnum,
5577 Output_segment* tls_segment,
5578 const elfcpp::Rela<size, false>& rela,
5579 unsigned int,
5580 typename elfcpp::Elf_types<size>::Elf_Addr value,
5581 unsigned char* view,
5582 section_size_type view_size)
5583 {
5584 // We need to examine the opcodes to figure out which instruction we
5585 // are looking at.
5586
5587 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
5588 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
5589
5590 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5591 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5592
5593 unsigned char op1 = view[-3];
5594 unsigned char op2 = view[-2];
5595 unsigned char op3 = view[-1];
5596 unsigned char reg = op3 >> 3;
5597
5598 if (op2 == 0x8b)
5599 {
5600 // movq
5601 if (op1 == 0x4c)
5602 view[-3] = 0x49;
5603 else if (size == 32 && op1 == 0x44)
5604 view[-3] = 0x41;
5605 view[-2] = 0xc7;
5606 view[-1] = 0xc0 | reg;
5607 }
5608 else if (reg == 4)
5609 {
5610 // Special handling for %rsp.
5611 if (op1 == 0x4c)
5612 view[-3] = 0x49;
5613 else if (size == 32 && op1 == 0x44)
5614 view[-3] = 0x41;
5615 view[-2] = 0x81;
5616 view[-1] = 0xc0 | reg;
5617 }
5618 else
5619 {
5620 // addq
5621 if (op1 == 0x4c)
5622 view[-3] = 0x4d;
5623 else if (size == 32 && op1 == 0x44)
5624 view[-3] = 0x45;
5625 view[-2] = 0x8d;
5626 view[-1] = 0x80 | reg | (reg << 3);
5627 }
5628
5629 if (tls_segment != NULL)
5630 value -= tls_segment->memsz();
5631 Relocate_functions<size, false>::rela32(view, value, 0);
5632 }
5633
5634 // Relocate section data.
5635
5636 template<int size>
5637 void
5638 Target_x86_64<size>::relocate_section(
5639 const Relocate_info<size, false>* relinfo,
5640 unsigned int sh_type,
5641 const unsigned char* prelocs,
5642 size_t reloc_count,
5643 Output_section* output_section,
5644 bool needs_special_offset_handling,
5645 unsigned char* view,
5646 typename elfcpp::Elf_types<size>::Elf_Addr address,
5647 section_size_type view_size,
5648 const Reloc_symbol_changes* reloc_symbol_changes)
5649 {
5650 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5651 Classify_reloc;
5652
5653 gold_assert(sh_type == elfcpp::SHT_RELA);
5654
5655 gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
5656 gold::Default_comdat_behavior, Classify_reloc>(
5657 relinfo,
5658 this,
5659 prelocs,
5660 reloc_count,
5661 output_section,
5662 needs_special_offset_handling,
5663 view,
5664 address,
5665 view_size,
5666 reloc_symbol_changes);
5667 }
5668
5669 // Apply an incremental relocation. Incremental relocations always refer
5670 // to global symbols.
5671
5672 template<int size>
5673 void
5674 Target_x86_64<size>::apply_relocation(
5675 const Relocate_info<size, false>* relinfo,
5676 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
5677 unsigned int r_type,
5678 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
5679 const Symbol* gsym,
5680 unsigned char* view,
5681 typename elfcpp::Elf_types<size>::Elf_Addr address,
5682 section_size_type view_size)
5683 {
5684 gold::apply_relocation<size, false, Target_x86_64<size>,
5685 typename Target_x86_64<size>::Relocate>(
5686 relinfo,
5687 this,
5688 r_offset,
5689 r_type,
5690 r_addend,
5691 gsym,
5692 view,
5693 address,
5694 view_size);
5695 }
5696
5697 // Scan the relocs during a relocatable link.
5698
5699 template<int size>
5700 void
5701 Target_x86_64<size>::scan_relocatable_relocs(
5702 Symbol_table* symtab,
5703 Layout* layout,
5704 Sized_relobj_file<size, false>* object,
5705 unsigned int data_shndx,
5706 unsigned int sh_type,
5707 const unsigned char* prelocs,
5708 size_t reloc_count,
5709 Output_section* output_section,
5710 bool needs_special_offset_handling,
5711 size_t local_symbol_count,
5712 const unsigned char* plocal_symbols,
5713 Relocatable_relocs* rr)
5714 {
5715 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5716 Classify_reloc;
5717 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
5718 Scan_relocatable_relocs;
5719
5720 gold_assert(sh_type == elfcpp::SHT_RELA);
5721
5722 gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
5723 symtab,
5724 layout,
5725 object,
5726 data_shndx,
5727 prelocs,
5728 reloc_count,
5729 output_section,
5730 needs_special_offset_handling,
5731 local_symbol_count,
5732 plocal_symbols,
5733 rr);
5734 }
5735
5736 // Scan the relocs for --emit-relocs.
5737
5738 template<int size>
5739 void
5740 Target_x86_64<size>::emit_relocs_scan(
5741 Symbol_table* symtab,
5742 Layout* layout,
5743 Sized_relobj_file<size, false>* object,
5744 unsigned int data_shndx,
5745 unsigned int sh_type,
5746 const unsigned char* prelocs,
5747 size_t reloc_count,
5748 Output_section* output_section,
5749 bool needs_special_offset_handling,
5750 size_t local_symbol_count,
5751 const unsigned char* plocal_syms,
5752 Relocatable_relocs* rr)
5753 {
5754 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5755 Classify_reloc;
5756 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
5757 Emit_relocs_strategy;
5758
5759 gold_assert(sh_type == elfcpp::SHT_RELA);
5760
5761 gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
5762 symtab,
5763 layout,
5764 object,
5765 data_shndx,
5766 prelocs,
5767 reloc_count,
5768 output_section,
5769 needs_special_offset_handling,
5770 local_symbol_count,
5771 plocal_syms,
5772 rr);
5773 }
5774
5775 // Relocate a section during a relocatable link.
5776
5777 template<int size>
5778 void
5779 Target_x86_64<size>::relocate_relocs(
5780 const Relocate_info<size, false>* relinfo,
5781 unsigned int sh_type,
5782 const unsigned char* prelocs,
5783 size_t reloc_count,
5784 Output_section* output_section,
5785 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
5786 unsigned char* view,
5787 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
5788 section_size_type view_size,
5789 unsigned char* reloc_view,
5790 section_size_type reloc_view_size)
5791 {
5792 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5793 Classify_reloc;
5794
5795 gold_assert(sh_type == elfcpp::SHT_RELA);
5796
5797 gold::relocate_relocs<size, false, Classify_reloc>(
5798 relinfo,
5799 prelocs,
5800 reloc_count,
5801 output_section,
5802 offset_in_output_section,
5803 view,
5804 view_address,
5805 view_size,
5806 reloc_view,
5807 reloc_view_size);
5808 }
5809
5810 // Return the value to use for a dynamic which requires special
5811 // treatment. This is how we support equality comparisons of function
5812 // pointers across shared library boundaries, as described in the
5813 // processor specific ABI supplement.
5814
5815 template<int size>
5816 uint64_t
5817 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
5818 {
5819 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
5820 return this->plt_address_for_global(gsym);
5821 }
5822
5823 // Return a string used to fill a code section with nops to take up
5824 // the specified length.
5825
5826 template<int size>
5827 std::string
5828 Target_x86_64<size>::do_code_fill(section_size_type length) const
5829 {
5830 if (length >= 16)
5831 {
5832 // Build a jmpq instruction to skip over the bytes.
5833 unsigned char jmp[5];
5834 jmp[0] = 0xe9;
5835 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
5836 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
5837 + std::string(length - 5, static_cast<char>(0x90)));
5838 }
5839
5840 // Nop sequences of various lengths.
5841 const char nop1[1] = { '\x90' }; // nop
5842 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
5843 const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5844 const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
5845 '\x00'};
5846 const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
5847 '\x00', '\x00' };
5848 const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
5849 '\x44', '\x00', '\x00' };
5850 const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
5851 '\x00', '\x00', '\x00',
5852 '\x00' };
5853 const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
5854 '\x00', '\x00', '\x00',
5855 '\x00', '\x00' };
5856 const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
5857 '\x84', '\x00', '\x00',
5858 '\x00', '\x00', '\x00' };
5859 const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5860 '\x1f', '\x84', '\x00',
5861 '\x00', '\x00', '\x00',
5862 '\x00' };
5863 const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
5864 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5865 '\x00', '\x00', '\x00',
5866 '\x00', '\x00' };
5867 const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
5868 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5869 '\x84', '\x00', '\x00',
5870 '\x00', '\x00', '\x00' };
5871 const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5872 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5873 '\x1f', '\x84', '\x00',
5874 '\x00', '\x00', '\x00',
5875 '\x00' };
5876 const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5877 '\x66', '\x66', '\x2e', // data16
5878 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5879 '\x00', '\x00', '\x00',
5880 '\x00', '\x00' };
5881 const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5882 '\x66', '\x66', '\x66', // data16; data16
5883 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5884 '\x84', '\x00', '\x00',
5885 '\x00', '\x00', '\x00' };
5886
5887 const char* nops[16] = {
5888 NULL,
5889 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
5890 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
5891 };
5892
5893 return std::string(nops[length], length);
5894 }
5895
5896 // Return the addend to use for a target specific relocation. The
5897 // only target specific relocation is R_X86_64_TLSDESC for a local
5898 // symbol. We want to set the addend is the offset of the local
5899 // symbol in the TLS segment.
5900
5901 template<int size>
5902 uint64_t
5903 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
5904 uint64_t) const
5905 {
5906 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
5907 uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
5908 gold_assert(intarg < this->tlsdesc_reloc_info_.size());
5909 const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
5910 const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
5911 gold_assert(psymval->is_tls_symbol());
5912 // The value of a TLS symbol is the offset in the TLS segment.
5913 return psymval->value(ti.object, 0);
5914 }
5915
5916 // Return the value to use for the base of a DW_EH_PE_datarel offset
5917 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
5918 // assembler can not write out the difference between two labels in
5919 // different sections, so instead of using a pc-relative value they
5920 // use an offset from the GOT.
5921
5922 template<int size>
5923 uint64_t
5924 Target_x86_64<size>::do_ehframe_datarel_base() const
5925 {
5926 gold_assert(this->global_offset_table_ != NULL);
5927 Symbol* sym = this->global_offset_table_;
5928 Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
5929 return ssym->value();
5930 }
5931
5932 // FNOFFSET in section SHNDX in OBJECT is the start of a function
5933 // compiled with -fsplit-stack. The function calls non-split-stack
5934 // code. We have to change the function so that it always ensures
5935 // that it has enough stack space to run some random function.
5936
5937 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
5938 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
5939 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
5940
5941 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
5942 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
5943 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
5944
5945 template<int size>
5946 void
5947 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
5948 section_offset_type fnoffset,
5949 section_size_type fnsize,
5950 const unsigned char*,
5951 size_t,
5952 unsigned char* view,
5953 section_size_type view_size,
5954 std::string* from,
5955 std::string* to) const
5956 {
5957 const char* const cmp_insn = reinterpret_cast<const char*>
5958 (size == 32 ? cmp_insn_32 : cmp_insn_64);
5959 const char* const lea_r10_insn = reinterpret_cast<const char*>
5960 (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
5961 const char* const lea_r11_insn = reinterpret_cast<const char*>
5962 (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
5963
5964 const size_t cmp_insn_len =
5965 (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
5966 const size_t lea_r10_insn_len =
5967 (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
5968 const size_t lea_r11_insn_len =
5969 (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
5970 const size_t nop_len = (size == 32 ? 7 : 8);
5971
5972 // The function starts with a comparison of the stack pointer and a
5973 // field in the TCB. This is followed by a jump.
5974
5975 // cmp %fs:NN,%rsp
5976 if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
5977 && fnsize > nop_len + 1)
5978 {
5979 // We will call __morestack if the carry flag is set after this
5980 // comparison. We turn the comparison into an stc instruction
5981 // and some nops.
5982 view[fnoffset] = '\xf9';
5983 this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
5984 }
5985 // lea NN(%rsp),%r10
5986 // lea NN(%rsp),%r11
5987 else if ((this->match_view(view, view_size, fnoffset,
5988 lea_r10_insn, lea_r10_insn_len)
5989 || this->match_view(view, view_size, fnoffset,
5990 lea_r11_insn, lea_r11_insn_len))
5991 && fnsize > 8)
5992 {
5993 // This is loading an offset from the stack pointer for a
5994 // comparison. The offset is negative, so we decrease the
5995 // offset by the amount of space we need for the stack. This
5996 // means we will avoid calling __morestack if there happens to
5997 // be plenty of space on the stack already.
5998 unsigned char* pval = view + fnoffset + 4;
5999 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
6000 val -= parameters->options().split_stack_adjust_size();
6001 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
6002 }
6003 else
6004 {
6005 if (!object->has_no_split_stack())
6006 object->error(_("failed to match split-stack sequence at "
6007 "section %u offset %0zx"),
6008 shndx, static_cast<size_t>(fnoffset));
6009 return;
6010 }
6011
6012 // We have to change the function so that it calls
6013 // __morestack_non_split instead of __morestack. The former will
6014 // allocate additional stack space.
6015 *from = "__morestack";
6016 *to = "__morestack_non_split";
6017 }
6018
6019 // The selector for x86_64 object files. Note this is never instantiated
6020 // directly. It's only used in Target_selector_x86_64_nacl, below.
6021
6022 template<int size>
6023 class Target_selector_x86_64 : public Target_selector_freebsd
6024 {
6025 public:
6026 Target_selector_x86_64()
6027 : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
6028 (size == 64
6029 ? "elf64-x86-64" : "elf32-x86-64"),
6030 (size == 64
6031 ? "elf64-x86-64-freebsd"
6032 : "elf32-x86-64-freebsd"),
6033 (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
6034 { }
6035
6036 Target*
6037 do_instantiate_target()
6038 { return new Target_x86_64<size>(); }
6039
6040 };
6041
6042 // NaCl variant. It uses different PLT contents.
6043
6044 template<int size>
6045 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
6046 {
6047 public:
6048 Output_data_plt_x86_64_nacl(Layout* layout,
6049 Output_data_got<64, false>* got,
6050 Output_data_got_plt_x86_64* got_plt,
6051 Output_data_space* got_irelative)
6052 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
6053 got, got_plt, got_irelative)
6054 { }
6055
6056 Output_data_plt_x86_64_nacl(Layout* layout,
6057 Output_data_got<64, false>* got,
6058 Output_data_got_plt_x86_64* got_plt,
6059 Output_data_space* got_irelative,
6060 unsigned int plt_count)
6061 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
6062 got, got_plt, got_irelative,
6063 plt_count)
6064 { }
6065
6066 protected:
6067 virtual unsigned int
6068 do_get_plt_entry_size() const
6069 { return plt_entry_size; }
6070
6071 virtual void
6072 do_add_eh_frame(Layout* layout)
6073 {
6074 layout->add_eh_frame_for_plt(this,
6075 this->plt_eh_frame_cie,
6076 this->plt_eh_frame_cie_size,
6077 plt_eh_frame_fde,
6078 plt_eh_frame_fde_size);
6079 }
6080
6081 virtual void
6082 do_fill_first_plt_entry(unsigned char* pov,
6083 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
6084 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
6085
6086 virtual unsigned int
6087 do_fill_plt_entry(unsigned char* pov,
6088 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6089 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6090 unsigned int got_offset,
6091 unsigned int plt_offset,
6092 unsigned int plt_index);
6093
6094 virtual void
6095 do_fill_tlsdesc_entry(unsigned char* pov,
6096 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6097 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6098 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
6099 unsigned int tlsdesc_got_offset,
6100 unsigned int plt_offset);
6101
6102 private:
6103 // The size of an entry in the PLT.
6104 static const int plt_entry_size = 64;
6105
6106 // The first entry in the PLT.
6107 static const unsigned char first_plt_entry[plt_entry_size];
6108
6109 // Other entries in the PLT for an executable.
6110 static const unsigned char plt_entry[plt_entry_size];
6111
6112 // The reserved TLSDESC entry in the PLT for an executable.
6113 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
6114
6115 // The .eh_frame unwind information for the PLT.
6116 static const int plt_eh_frame_fde_size = 32;
6117 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
6118 };
6119
6120 template<int size>
6121 class Target_x86_64_nacl : public Target_x86_64<size>
6122 {
6123 public:
6124 Target_x86_64_nacl()
6125 : Target_x86_64<size>(&x86_64_nacl_info)
6126 { }
6127
6128 virtual Output_data_plt_x86_64<size>*
6129 do_make_data_plt(Layout* layout,
6130 Output_data_got<64, false>* got,
6131 Output_data_got_plt_x86_64* got_plt,
6132 Output_data_space* got_irelative)
6133 {
6134 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
6135 got_irelative);
6136 }
6137
6138 virtual Output_data_plt_x86_64<size>*
6139 do_make_data_plt(Layout* layout,
6140 Output_data_got<64, false>* got,
6141 Output_data_got_plt_x86_64* got_plt,
6142 Output_data_space* got_irelative,
6143 unsigned int plt_count)
6144 {
6145 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
6146 got_irelative,
6147 plt_count);
6148 }
6149
6150 virtual std::string
6151 do_code_fill(section_size_type length) const;
6152
6153 private:
6154 static const Target::Target_info x86_64_nacl_info;
6155 };
6156
6157 template<>
6158 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
6159 {
6160 64, // size
6161 false, // is_big_endian
6162 elfcpp::EM_X86_64, // machine_code
6163 false, // has_make_symbol
6164 false, // has_resolve
6165 true, // has_code_fill
6166 true, // is_default_stack_executable
6167 true, // can_icf_inline_merge_sections
6168 '\0', // wrap_char
6169 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
6170 0x20000, // default_text_segment_address
6171 0x10000, // abi_pagesize (overridable by -z max-page-size)
6172 0x10000, // common_pagesize (overridable by -z common-page-size)
6173 true, // isolate_execinstr
6174 0x10000000, // rosegment_gap
6175 elfcpp::SHN_UNDEF, // small_common_shndx
6176 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
6177 0, // small_common_section_flags
6178 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
6179 NULL, // attributes_section
6180 NULL, // attributes_vendor
6181 "_start", // entry_symbol_name
6182 32, // hash_entry_size
6183 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
6184 };
6185
6186 template<>
6187 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
6188 {
6189 32, // size
6190 false, // is_big_endian
6191 elfcpp::EM_X86_64, // machine_code
6192 false, // has_make_symbol
6193 false, // has_resolve
6194 true, // has_code_fill
6195 true, // is_default_stack_executable
6196 true, // can_icf_inline_merge_sections
6197 '\0', // wrap_char
6198 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
6199 0x20000, // default_text_segment_address
6200 0x10000, // abi_pagesize (overridable by -z max-page-size)
6201 0x10000, // common_pagesize (overridable by -z common-page-size)
6202 true, // isolate_execinstr
6203 0x10000000, // rosegment_gap
6204 elfcpp::SHN_UNDEF, // small_common_shndx
6205 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
6206 0, // small_common_section_flags
6207 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
6208 NULL, // attributes_section
6209 NULL, // attributes_vendor
6210 "_start", // entry_symbol_name
6211 32, // hash_entry_size
6212 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
6213 };
6214
6215 #define NACLMASK 0xe0 // 32-byte alignment mask.
6216
6217 // The first entry in the PLT.
6218
6219 template<int size>
6220 const unsigned char
6221 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
6222 {
6223 0xff, 0x35, // pushq contents of memory address
6224 0, 0, 0, 0, // replaced with address of .got + 8
6225 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
6226 0, 0, 0, 0, // replaced with address of .got + 16
6227 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
6228 0x4d, 0x01, 0xfb, // add %r15, %r11
6229 0x41, 0xff, 0xe3, // jmpq *%r11
6230
6231 // 9-byte nop sequence to pad out to the next 32-byte boundary.
6232 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
6233
6234 // 32 bytes of nop to pad out to the standard size
6235 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6236 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6237 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6238 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6239 0x66, // excess data32 prefix
6240 0x90 // nop
6241 };
6242
6243 template<int size>
6244 void
6245 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
6246 unsigned char* pov,
6247 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6248 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
6249 {
6250 memcpy(pov, first_plt_entry, plt_entry_size);
6251 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
6252 (got_address + 8
6253 - (plt_address + 2 + 4)));
6254 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
6255 (got_address + 16
6256 - (plt_address + 9 + 4)));
6257 }
6258
6259 // Subsequent entries in the PLT.
6260
6261 template<int size>
6262 const unsigned char
6263 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
6264 {
6265 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
6266 0, 0, 0, 0, // replaced with address of symbol in .got
6267 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
6268 0x4d, 0x01, 0xfb, // add %r15, %r11
6269 0x41, 0xff, 0xe3, // jmpq *%r11
6270
6271 // 15-byte nop sequence to pad out to the next 32-byte boundary.
6272 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6273 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6274
6275 // Lazy GOT entries point here (32-byte aligned).
6276 0x68, // pushq immediate
6277 0, 0, 0, 0, // replaced with index into relocation table
6278 0xe9, // jmp relative
6279 0, 0, 0, 0, // replaced with offset to start of .plt0
6280
6281 // 22 bytes of nop to pad out to the standard size.
6282 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6283 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6284 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
6285 };
6286
6287 template<int size>
6288 unsigned int
6289 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
6290 unsigned char* pov,
6291 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6292 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6293 unsigned int got_offset,
6294 unsigned int plt_offset,
6295 unsigned int plt_index)
6296 {
6297 memcpy(pov, plt_entry, plt_entry_size);
6298 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
6299 (got_address + got_offset
6300 - (plt_address + plt_offset
6301 + 3 + 4)));
6302
6303 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
6304 elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
6305 - (plt_offset + 38 + 4));
6306
6307 return 32;
6308 }
6309
6310 // The reserved TLSDESC entry in the PLT.
6311
6312 template<int size>
6313 const unsigned char
6314 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
6315 {
6316 0xff, 0x35, // pushq x(%rip)
6317 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
6318 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
6319 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
6320 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
6321 0x4d, 0x01, 0xfb, // add %r15, %r11
6322 0x41, 0xff, 0xe3, // jmpq *%r11
6323
6324 // 41 bytes of nop to pad out to the standard size.
6325 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6326 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6327 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6328 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6329 0x66, 0x66, // excess data32 prefixes
6330 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6331 };
6332
6333 template<int size>
6334 void
6335 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
6336 unsigned char* pov,
6337 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6338 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6339 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
6340 unsigned int tlsdesc_got_offset,
6341 unsigned int plt_offset)
6342 {
6343 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
6344 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
6345 (got_address + 8
6346 - (plt_address + plt_offset
6347 + 2 + 4)));
6348 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
6349 (got_base
6350 + tlsdesc_got_offset
6351 - (plt_address + plt_offset
6352 + 9 + 4)));
6353 }
6354
6355 // The .eh_frame unwind information for the PLT.
6356
6357 template<int size>
6358 const unsigned char
6359 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
6360 {
6361 0, 0, 0, 0, // Replaced with offset to .plt.
6362 0, 0, 0, 0, // Replaced with size of .plt.
6363 0, // Augmentation size.
6364 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
6365 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
6366 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
6367 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
6368 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
6369 13, // Block length.
6370 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
6371 elfcpp::DW_OP_breg16, 0, // Push %rip.
6372 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
6373 elfcpp::DW_OP_and, // & (%rip & 0x3f).
6374 elfcpp::DW_OP_const1u, 37, // Push 0x25.
6375 elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25)
6376 elfcpp::DW_OP_lit3, // Push 3.
6377 elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3)
6378 elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
6379 elfcpp::DW_CFA_nop, // Align to 32 bytes.
6380 elfcpp::DW_CFA_nop
6381 };
6382
6383 // Return a string used to fill a code section with nops.
6384 // For NaCl, long NOPs are only valid if they do not cross
6385 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
6386 template<int size>
6387 std::string
6388 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
6389 {
6390 return std::string(length, static_cast<char>(0x90));
6391 }
6392
6393 // The selector for x86_64-nacl object files.
6394
6395 template<int size>
6396 class Target_selector_x86_64_nacl
6397 : public Target_selector_nacl<Target_selector_x86_64<size>,
6398 Target_x86_64_nacl<size> >
6399 {
6400 public:
6401 Target_selector_x86_64_nacl()
6402 : Target_selector_nacl<Target_selector_x86_64<size>,
6403 Target_x86_64_nacl<size> >("x86-64",
6404 size == 64
6405 ? "elf64-x86-64-nacl"
6406 : "elf32-x86-64-nacl",
6407 size == 64
6408 ? "elf_x86_64_nacl"
6409 : "elf32_x86_64_nacl")
6410 { }
6411 };
6412
6413 Target_selector_x86_64_nacl<64> target_selector_x86_64;
6414 Target_selector_x86_64_nacl<32> target_selector_x32;
6415
6416 } // End anonymous namespace.
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