]> git.ipfire.org Git - thirdparty/binutils-gdb.git/blob - gold/x86_64.cc
[binutils, ARM, 4/16] BF insns infrastructure with array of relocs in struct arm_it
[thirdparty/binutils-gdb.git] / gold / x86_64.cc
1 // x86_64.cc -- x86_64 target support for gold.
2
3 // Copyright (C) 2006-2019 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_isa_1_used_(0), object_feature_1_(0),
710 seen_first_object_(false)
711 { }
712
713 // Hook for a new output section.
714 void
715 do_new_output_section(Output_section*) const;
716
717 // Scan the relocations to look for symbol adjustments.
718 void
719 gc_process_relocs(Symbol_table* symtab,
720 Layout* layout,
721 Sized_relobj_file<size, false>* object,
722 unsigned int data_shndx,
723 unsigned int sh_type,
724 const unsigned char* prelocs,
725 size_t reloc_count,
726 Output_section* output_section,
727 bool needs_special_offset_handling,
728 size_t local_symbol_count,
729 const unsigned char* plocal_symbols);
730
731 // Scan the relocations to look for symbol adjustments.
732 void
733 scan_relocs(Symbol_table* symtab,
734 Layout* layout,
735 Sized_relobj_file<size, false>* object,
736 unsigned int data_shndx,
737 unsigned int sh_type,
738 const unsigned char* prelocs,
739 size_t reloc_count,
740 Output_section* output_section,
741 bool needs_special_offset_handling,
742 size_t local_symbol_count,
743 const unsigned char* plocal_symbols);
744
745 // Finalize the sections.
746 void
747 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
748
749 // Return the value to use for a dynamic which requires special
750 // treatment.
751 uint64_t
752 do_dynsym_value(const Symbol*) const;
753
754 // Relocate a section.
755 void
756 relocate_section(const Relocate_info<size, false>*,
757 unsigned int sh_type,
758 const unsigned char* prelocs,
759 size_t reloc_count,
760 Output_section* output_section,
761 bool needs_special_offset_handling,
762 unsigned char* view,
763 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
764 section_size_type view_size,
765 const Reloc_symbol_changes*);
766
767 // Scan the relocs during a relocatable link.
768 void
769 scan_relocatable_relocs(Symbol_table* symtab,
770 Layout* layout,
771 Sized_relobj_file<size, false>* object,
772 unsigned int data_shndx,
773 unsigned int sh_type,
774 const unsigned char* prelocs,
775 size_t reloc_count,
776 Output_section* output_section,
777 bool needs_special_offset_handling,
778 size_t local_symbol_count,
779 const unsigned char* plocal_symbols,
780 Relocatable_relocs*);
781
782 // Scan the relocs for --emit-relocs.
783 void
784 emit_relocs_scan(Symbol_table* symtab,
785 Layout* layout,
786 Sized_relobj_file<size, false>* object,
787 unsigned int data_shndx,
788 unsigned int sh_type,
789 const unsigned char* prelocs,
790 size_t reloc_count,
791 Output_section* output_section,
792 bool needs_special_offset_handling,
793 size_t local_symbol_count,
794 const unsigned char* plocal_syms,
795 Relocatable_relocs* rr);
796
797 // Emit relocations for a section.
798 void
799 relocate_relocs(
800 const Relocate_info<size, false>*,
801 unsigned int sh_type,
802 const unsigned char* prelocs,
803 size_t reloc_count,
804 Output_section* output_section,
805 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
806 unsigned char* view,
807 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
808 section_size_type view_size,
809 unsigned char* reloc_view,
810 section_size_type reloc_view_size);
811
812 // Return a string used to fill a code section with nops.
813 std::string
814 do_code_fill(section_size_type length) const;
815
816 // Return whether SYM is defined by the ABI.
817 bool
818 do_is_defined_by_abi(const Symbol* sym) const
819 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
820
821 // Return the symbol index to use for a target specific relocation.
822 // The only target specific relocation is R_X86_64_TLSDESC for a
823 // local symbol, which is an absolute reloc.
824 unsigned int
825 do_reloc_symbol_index(void*, unsigned int r_type) const
826 {
827 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
828 return 0;
829 }
830
831 // Return the addend to use for a target specific relocation.
832 uint64_t
833 do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
834
835 // Return the PLT section.
836 uint64_t
837 do_plt_address_for_global(const Symbol* gsym) const
838 { return this->plt_section()->address_for_global(gsym); }
839
840 uint64_t
841 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
842 { return this->plt_section()->address_for_local(relobj, symndx); }
843
844 // This function should be defined in targets that can use relocation
845 // types to determine (implemented in local_reloc_may_be_function_pointer
846 // and global_reloc_may_be_function_pointer)
847 // if a function's pointer is taken. ICF uses this in safe mode to only
848 // fold those functions whose pointer is defintely not taken. For x86_64
849 // pie binaries, safe ICF cannot be done by looking at only relocation
850 // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
851 // opcode is checked as well to distinguish a function call from taking
852 // a function's pointer.
853 bool
854 do_can_check_for_function_pointers() const
855 { return true; }
856
857 // Return the base for a DW_EH_PE_datarel encoding.
858 uint64_t
859 do_ehframe_datarel_base() const;
860
861 // Adjust -fsplit-stack code which calls non-split-stack code.
862 void
863 do_calls_non_split(Relobj* object, unsigned int shndx,
864 section_offset_type fnoffset, section_size_type fnsize,
865 const unsigned char* prelocs, size_t reloc_count,
866 unsigned char* view, section_size_type view_size,
867 std::string* from, std::string* to) const;
868
869 // Return the size of the GOT section.
870 section_size_type
871 got_size() const
872 {
873 gold_assert(this->got_ != NULL);
874 return this->got_->data_size();
875 }
876
877 // Return the number of entries in the GOT.
878 unsigned int
879 got_entry_count() const
880 {
881 if (this->got_ == NULL)
882 return 0;
883 return this->got_size() / 8;
884 }
885
886 // Return the number of entries in the PLT.
887 unsigned int
888 plt_entry_count() const;
889
890 // Return the offset of the first non-reserved PLT entry.
891 unsigned int
892 first_plt_entry_offset() const;
893
894 // Return the size of each PLT entry.
895 unsigned int
896 plt_entry_size() const;
897
898 // Return the size of each GOT entry.
899 unsigned int
900 got_entry_size() const
901 { return 8; };
902
903 // Create the GOT section for an incremental update.
904 Output_data_got_base*
905 init_got_plt_for_update(Symbol_table* symtab,
906 Layout* layout,
907 unsigned int got_count,
908 unsigned int plt_count);
909
910 // Reserve a GOT entry for a local symbol, and regenerate any
911 // necessary dynamic relocations.
912 void
913 reserve_local_got_entry(unsigned int got_index,
914 Sized_relobj<size, false>* obj,
915 unsigned int r_sym,
916 unsigned int got_type);
917
918 // Reserve a GOT entry for a global symbol, and regenerate any
919 // necessary dynamic relocations.
920 void
921 reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
922 unsigned int got_type);
923
924 // Register an existing PLT entry for a global symbol.
925 void
926 register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
927 Symbol* gsym);
928
929 // Force a COPY relocation for a given symbol.
930 void
931 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
932
933 // Apply an incremental relocation.
934 void
935 apply_relocation(const Relocate_info<size, false>* relinfo,
936 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
937 unsigned int r_type,
938 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
939 const Symbol* gsym,
940 unsigned char* view,
941 typename elfcpp::Elf_types<size>::Elf_Addr address,
942 section_size_type view_size);
943
944 // Add a new reloc argument, returning the index in the vector.
945 size_t
946 add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
947 {
948 this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
949 return this->tlsdesc_reloc_info_.size() - 1;
950 }
951
952 Output_data_plt_x86_64<size>*
953 make_data_plt(Layout* layout,
954 Output_data_got<64, false>* got,
955 Output_data_got_plt_x86_64* got_plt,
956 Output_data_space* got_irelative)
957 {
958 return this->do_make_data_plt(layout, got, got_plt, got_irelative);
959 }
960
961 Output_data_plt_x86_64<size>*
962 make_data_plt(Layout* layout,
963 Output_data_got<64, false>* got,
964 Output_data_got_plt_x86_64* got_plt,
965 Output_data_space* got_irelative,
966 unsigned int plt_count)
967 {
968 return this->do_make_data_plt(layout, got, got_plt, got_irelative,
969 plt_count);
970 }
971
972 virtual Output_data_plt_x86_64<size>*
973 do_make_data_plt(Layout* layout,
974 Output_data_got<64, false>* got,
975 Output_data_got_plt_x86_64* got_plt,
976 Output_data_space* got_irelative);
977
978 virtual Output_data_plt_x86_64<size>*
979 do_make_data_plt(Layout* layout,
980 Output_data_got<64, false>* got,
981 Output_data_got_plt_x86_64* got_plt,
982 Output_data_space* got_irelative,
983 unsigned int plt_count);
984
985 private:
986 // The class which scans relocations.
987 class Scan
988 {
989 public:
990 Scan()
991 : issued_non_pic_error_(false)
992 { }
993
994 static inline int
995 get_reference_flags(unsigned int r_type);
996
997 inline void
998 local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
999 Sized_relobj_file<size, false>* object,
1000 unsigned int data_shndx,
1001 Output_section* output_section,
1002 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
1003 const elfcpp::Sym<size, false>& lsym,
1004 bool is_discarded);
1005
1006 inline void
1007 global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
1008 Sized_relobj_file<size, false>* object,
1009 unsigned int data_shndx,
1010 Output_section* output_section,
1011 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
1012 Symbol* gsym);
1013
1014 inline bool
1015 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
1016 Target_x86_64* target,
1017 Sized_relobj_file<size, false>* object,
1018 unsigned int data_shndx,
1019 Output_section* output_section,
1020 const elfcpp::Rela<size, false>& reloc,
1021 unsigned int r_type,
1022 const elfcpp::Sym<size, false>& lsym);
1023
1024 inline bool
1025 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
1026 Target_x86_64* target,
1027 Sized_relobj_file<size, false>* object,
1028 unsigned int data_shndx,
1029 Output_section* output_section,
1030 const elfcpp::Rela<size, false>& reloc,
1031 unsigned int r_type,
1032 Symbol* gsym);
1033
1034 private:
1035 static void
1036 unsupported_reloc_local(Sized_relobj_file<size, false>*,
1037 unsigned int r_type);
1038
1039 static void
1040 unsupported_reloc_global(Sized_relobj_file<size, false>*,
1041 unsigned int r_type, Symbol*);
1042
1043 void
1044 check_non_pic(Relobj*, unsigned int r_type, Symbol*);
1045
1046 inline bool
1047 possible_function_pointer_reloc(Sized_relobj_file<size, false>* src_obj,
1048 unsigned int src_indx,
1049 unsigned int r_offset,
1050 unsigned int r_type);
1051
1052 bool
1053 reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
1054 unsigned int r_type);
1055
1056 // Whether we have issued an error about a non-PIC compilation.
1057 bool issued_non_pic_error_;
1058 };
1059
1060 // The class which implements relocation.
1061 class Relocate
1062 {
1063 public:
1064 Relocate()
1065 : skip_call_tls_get_addr_(false)
1066 { }
1067
1068 ~Relocate()
1069 {
1070 if (this->skip_call_tls_get_addr_)
1071 {
1072 // FIXME: This needs to specify the location somehow.
1073 gold_error(_("missing expected TLS relocation"));
1074 }
1075 }
1076
1077 // Do a relocation. Return false if the caller should not issue
1078 // any warnings about this relocation.
1079 inline bool
1080 relocate(const Relocate_info<size, false>*, unsigned int,
1081 Target_x86_64*, Output_section*, size_t, const unsigned char*,
1082 const Sized_symbol<size>*, const Symbol_value<size>*,
1083 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
1084 section_size_type);
1085
1086 private:
1087 // Do a TLS relocation.
1088 inline void
1089 relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
1090 size_t relnum, const elfcpp::Rela<size, false>&,
1091 unsigned int r_type, const Sized_symbol<size>*,
1092 const Symbol_value<size>*,
1093 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
1094 section_size_type);
1095
1096 // Do a TLS General-Dynamic to Initial-Exec transition.
1097 inline void
1098 tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1099 const elfcpp::Rela<size, false>&, unsigned int r_type,
1100 typename elfcpp::Elf_types<size>::Elf_Addr value,
1101 unsigned char* view,
1102 typename elfcpp::Elf_types<size>::Elf_Addr,
1103 section_size_type view_size);
1104
1105 // Do a TLS General-Dynamic to Local-Exec transition.
1106 inline void
1107 tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1108 Output_segment* tls_segment,
1109 const elfcpp::Rela<size, false>&, unsigned int r_type,
1110 typename elfcpp::Elf_types<size>::Elf_Addr value,
1111 unsigned char* view,
1112 section_size_type view_size);
1113
1114 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
1115 inline void
1116 tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1117 const elfcpp::Rela<size, false>&, unsigned int r_type,
1118 typename elfcpp::Elf_types<size>::Elf_Addr value,
1119 unsigned char* view,
1120 typename elfcpp::Elf_types<size>::Elf_Addr,
1121 section_size_type view_size);
1122
1123 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1124 inline void
1125 tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1126 Output_segment* tls_segment,
1127 const elfcpp::Rela<size, false>&, unsigned int r_type,
1128 typename elfcpp::Elf_types<size>::Elf_Addr value,
1129 unsigned char* view,
1130 section_size_type view_size);
1131
1132 // Do a TLS Local-Dynamic to Local-Exec transition.
1133 inline void
1134 tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
1135 Output_segment* tls_segment,
1136 const elfcpp::Rela<size, false>&, unsigned int r_type,
1137 typename elfcpp::Elf_types<size>::Elf_Addr value,
1138 unsigned char* view,
1139 section_size_type view_size);
1140
1141 // Do a TLS Initial-Exec to Local-Exec transition.
1142 static inline void
1143 tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
1144 Output_segment* tls_segment,
1145 const elfcpp::Rela<size, false>&, unsigned int r_type,
1146 typename elfcpp::Elf_types<size>::Elf_Addr value,
1147 unsigned char* view,
1148 section_size_type view_size);
1149
1150 // This is set if we should skip the next reloc, which should be a
1151 // PLT32 reloc against ___tls_get_addr.
1152 bool skip_call_tls_get_addr_;
1153 };
1154
1155 // Check if relocation against this symbol is a candidate for
1156 // conversion from
1157 // mov foo@GOTPCREL(%rip), %reg
1158 // to lea foo(%rip), %reg.
1159 template<class View_type>
1160 static inline bool
1161 can_convert_mov_to_lea(const Symbol* gsym, unsigned int r_type,
1162 size_t r_offset, View_type* view)
1163 {
1164 gold_assert(gsym != NULL);
1165 // We cannot do the conversion unless it's one of these relocations.
1166 if (r_type != elfcpp::R_X86_64_GOTPCREL
1167 && r_type != elfcpp::R_X86_64_GOTPCRELX
1168 && r_type != elfcpp::R_X86_64_REX_GOTPCRELX)
1169 return false;
1170 // We cannot convert references to IFUNC symbols, or to symbols that
1171 // are not local to the current module.
1172 // We can't do predefined symbols because they may become undefined
1173 // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1174 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1175 || gsym->is_undefined()
1176 || gsym->is_predefined()
1177 || gsym->is_from_dynobj()
1178 || gsym->is_preemptible())
1179 return false;
1180 // If we are building a shared object and the symbol is protected, we may
1181 // need to go through the GOT.
1182 if (parameters->options().shared()
1183 && gsym->visibility() == elfcpp::STV_PROTECTED)
1184 return false;
1185 // We cannot convert references to the _DYNAMIC symbol.
1186 if (strcmp(gsym->name(), "_DYNAMIC") == 0)
1187 return false;
1188 // Check for a MOV opcode.
1189 return (*view)[r_offset - 2] == 0x8b;
1190 }
1191
1192 // Convert
1193 // callq *foo@GOTPCRELX(%rip) to
1194 // addr32 callq foo
1195 // and jmpq *foo@GOTPCRELX(%rip) to
1196 // jmpq foo
1197 // nop
1198 template<class View_type>
1199 static inline bool
1200 can_convert_callq_to_direct(const Symbol* gsym, unsigned int r_type,
1201 size_t r_offset, View_type* view)
1202 {
1203 gold_assert(gsym != NULL);
1204 // We cannot do the conversion unless it's a GOTPCRELX relocation.
1205 if (r_type != elfcpp::R_X86_64_GOTPCRELX)
1206 return false;
1207 // We cannot convert references to IFUNC symbols, or to symbols that
1208 // are not local to the current module.
1209 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1210 || gsym->is_undefined ()
1211 || gsym->is_from_dynobj()
1212 || gsym->is_preemptible())
1213 return false;
1214 // Check for a CALLQ or JMPQ opcode.
1215 return ((*view)[r_offset - 2] == 0xff
1216 && ((*view)[r_offset - 1] == 0x15
1217 || (*view)[r_offset - 1] == 0x25));
1218 }
1219
1220 // Adjust TLS relocation type based on the options and whether this
1221 // is a local symbol.
1222 static tls::Tls_optimization
1223 optimize_tls_reloc(bool is_final, int r_type);
1224
1225 // Get the GOT section, creating it if necessary.
1226 Output_data_got<64, false>*
1227 got_section(Symbol_table*, Layout*);
1228
1229 // Get the GOT PLT section.
1230 Output_data_got_plt_x86_64*
1231 got_plt_section() const
1232 {
1233 gold_assert(this->got_plt_ != NULL);
1234 return this->got_plt_;
1235 }
1236
1237 // Get the GOT section for TLSDESC entries.
1238 Output_data_got<64, false>*
1239 got_tlsdesc_section() const
1240 {
1241 gold_assert(this->got_tlsdesc_ != NULL);
1242 return this->got_tlsdesc_;
1243 }
1244
1245 // Create the PLT section.
1246 void
1247 make_plt_section(Symbol_table* symtab, Layout* layout);
1248
1249 // Create a PLT entry for a global symbol.
1250 void
1251 make_plt_entry(Symbol_table*, Layout*, Symbol*);
1252
1253 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1254 void
1255 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
1256 Sized_relobj_file<size, false>* relobj,
1257 unsigned int local_sym_index);
1258
1259 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1260 void
1261 define_tls_base_symbol(Symbol_table*, Layout*);
1262
1263 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1264 void
1265 reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
1266
1267 // Create a GOT entry for the TLS module index.
1268 unsigned int
1269 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1270 Sized_relobj_file<size, false>* object);
1271
1272 // Get the PLT section.
1273 Output_data_plt_x86_64<size>*
1274 plt_section() const
1275 {
1276 gold_assert(this->plt_ != NULL);
1277 return this->plt_;
1278 }
1279
1280 // Get the dynamic reloc section, creating it if necessary.
1281 Reloc_section*
1282 rela_dyn_section(Layout*);
1283
1284 // Get the section to use for TLSDESC relocations.
1285 Reloc_section*
1286 rela_tlsdesc_section(Layout*) const;
1287
1288 // Get the section to use for IRELATIVE relocations.
1289 Reloc_section*
1290 rela_irelative_section(Layout*);
1291
1292 // Add a potential copy relocation.
1293 void
1294 copy_reloc(Symbol_table* symtab, Layout* layout,
1295 Sized_relobj_file<size, false>* object,
1296 unsigned int shndx, Output_section* output_section,
1297 Symbol* sym, const elfcpp::Rela<size, false>& reloc)
1298 {
1299 unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1300 this->copy_relocs_.copy_reloc(symtab, layout,
1301 symtab->get_sized_symbol<size>(sym),
1302 object, shndx, output_section,
1303 r_type, reloc.get_r_offset(),
1304 reloc.get_r_addend(),
1305 this->rela_dyn_section(layout));
1306 }
1307
1308 // Record a target-specific program property in the .note.gnu.property
1309 // section.
1310 void
1311 record_gnu_property(unsigned int, unsigned int, size_t,
1312 const unsigned char*, const Object*);
1313
1314 // Merge the target-specific program properties from the current object.
1315 void
1316 merge_gnu_properties(const Object*);
1317
1318 // Finalize the target-specific program properties and add them back to
1319 // the layout.
1320 void
1321 do_finalize_gnu_properties(Layout*) const;
1322
1323 // Information about this specific target which we pass to the
1324 // general Target structure.
1325 static const Target::Target_info x86_64_info;
1326
1327 // The types of GOT entries needed for this platform.
1328 // These values are exposed to the ABI in an incremental link.
1329 // Do not renumber existing values without changing the version
1330 // number of the .gnu_incremental_inputs section.
1331 enum Got_type
1332 {
1333 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
1334 GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
1335 GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
1336 GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
1337 };
1338
1339 // This type is used as the argument to the target specific
1340 // relocation routines. The only target specific reloc is
1341 // R_X86_64_TLSDESC against a local symbol.
1342 struct Tlsdesc_info
1343 {
1344 Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1345 : object(a_object), r_sym(a_r_sym)
1346 { }
1347
1348 // The object in which the local symbol is defined.
1349 Sized_relobj_file<size, false>* object;
1350 // The local symbol index in the object.
1351 unsigned int r_sym;
1352 };
1353
1354 // The GOT section.
1355 Output_data_got<64, false>* got_;
1356 // The PLT section.
1357 Output_data_plt_x86_64<size>* plt_;
1358 // The GOT PLT section.
1359 Output_data_got_plt_x86_64* got_plt_;
1360 // The GOT section for IRELATIVE relocations.
1361 Output_data_space* got_irelative_;
1362 // The GOT section for TLSDESC relocations.
1363 Output_data_got<64, false>* got_tlsdesc_;
1364 // The _GLOBAL_OFFSET_TABLE_ symbol.
1365 Symbol* global_offset_table_;
1366 // The dynamic reloc section.
1367 Reloc_section* rela_dyn_;
1368 // The section to use for IRELATIVE relocs.
1369 Reloc_section* rela_irelative_;
1370 // Relocs saved to avoid a COPY reloc.
1371 Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1372 // Offset of the GOT entry for the TLS module index.
1373 unsigned int got_mod_index_offset_;
1374 // We handle R_X86_64_TLSDESC against a local symbol as a target
1375 // specific relocation. Here we store the object and local symbol
1376 // index for the relocation.
1377 std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1378 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1379 bool tls_base_symbol_defined_;
1380 // Target-specific program properties, from .note.gnu.property section.
1381 // Each bit represents a specific feature.
1382 uint32_t isa_1_used_;
1383 uint32_t isa_1_needed_;
1384 uint32_t feature_1_;
1385 // Target-specific properties from the current object.
1386 // These bits get ORed into ISA_1_USED_ after all properties for the object
1387 // have been processed. But if either is all zeroes (as when the property
1388 // is absent from an object), the result should be all zeroes.
1389 // (See PR ld/23486.)
1390 uint32_t object_isa_1_used_;
1391 // These bits get ANDed into FEATURE_1_ after all properties for the object
1392 // have been processed.
1393 uint32_t object_feature_1_;
1394 // Whether we have seen our first object, for use in initializing FEATURE_1_.
1395 bool seen_first_object_;
1396 };
1397
1398 template<>
1399 const Target::Target_info Target_x86_64<64>::x86_64_info =
1400 {
1401 64, // size
1402 false, // is_big_endian
1403 elfcpp::EM_X86_64, // machine_code
1404 false, // has_make_symbol
1405 false, // has_resolve
1406 true, // has_code_fill
1407 true, // is_default_stack_executable
1408 true, // can_icf_inline_merge_sections
1409 '\0', // wrap_char
1410 "/lib/ld64.so.1", // program interpreter
1411 0x400000, // default_text_segment_address
1412 0x1000, // abi_pagesize (overridable by -z max-page-size)
1413 0x1000, // common_pagesize (overridable by -z common-page-size)
1414 false, // isolate_execinstr
1415 0, // rosegment_gap
1416 elfcpp::SHN_UNDEF, // small_common_shndx
1417 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1418 0, // small_common_section_flags
1419 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1420 NULL, // attributes_section
1421 NULL, // attributes_vendor
1422 "_start", // entry_symbol_name
1423 32, // hash_entry_size
1424 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
1425 };
1426
1427 template<>
1428 const Target::Target_info Target_x86_64<32>::x86_64_info =
1429 {
1430 32, // size
1431 false, // is_big_endian
1432 elfcpp::EM_X86_64, // machine_code
1433 false, // has_make_symbol
1434 false, // has_resolve
1435 true, // has_code_fill
1436 true, // is_default_stack_executable
1437 true, // can_icf_inline_merge_sections
1438 '\0', // wrap_char
1439 "/libx32/ldx32.so.1", // program interpreter
1440 0x400000, // default_text_segment_address
1441 0x1000, // abi_pagesize (overridable by -z max-page-size)
1442 0x1000, // common_pagesize (overridable by -z common-page-size)
1443 false, // isolate_execinstr
1444 0, // rosegment_gap
1445 elfcpp::SHN_UNDEF, // small_common_shndx
1446 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1447 0, // small_common_section_flags
1448 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1449 NULL, // attributes_section
1450 NULL, // attributes_vendor
1451 "_start", // entry_symbol_name
1452 32, // hash_entry_size
1453 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
1454 };
1455
1456 // This is called when a new output section is created. This is where
1457 // we handle the SHF_X86_64_LARGE.
1458
1459 template<int size>
1460 void
1461 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1462 {
1463 if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1464 os->set_is_large_section();
1465 }
1466
1467 // Get the GOT section, creating it if necessary.
1468
1469 template<int size>
1470 Output_data_got<64, false>*
1471 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1472 {
1473 if (this->got_ == NULL)
1474 {
1475 gold_assert(symtab != NULL && layout != NULL);
1476
1477 // When using -z now, we can treat .got.plt as a relro section.
1478 // Without -z now, it is modified after program startup by lazy
1479 // PLT relocations.
1480 bool is_got_plt_relro = parameters->options().now();
1481 Output_section_order got_order = (is_got_plt_relro
1482 ? ORDER_RELRO
1483 : ORDER_RELRO_LAST);
1484 Output_section_order got_plt_order = (is_got_plt_relro
1485 ? ORDER_RELRO
1486 : ORDER_NON_RELRO_FIRST);
1487
1488 this->got_ = new Output_data_got<64, false>();
1489
1490 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1491 (elfcpp::SHF_ALLOC
1492 | elfcpp::SHF_WRITE),
1493 this->got_, got_order, true);
1494
1495 this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1496 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1497 (elfcpp::SHF_ALLOC
1498 | elfcpp::SHF_WRITE),
1499 this->got_plt_, got_plt_order,
1500 is_got_plt_relro);
1501
1502 // The first three entries are reserved.
1503 this->got_plt_->set_current_data_size(3 * 8);
1504
1505 if (!is_got_plt_relro)
1506 {
1507 // Those bytes can go into the relro segment.
1508 layout->increase_relro(3 * 8);
1509 }
1510
1511 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1512 this->global_offset_table_ =
1513 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1514 Symbol_table::PREDEFINED,
1515 this->got_plt_,
1516 0, 0, elfcpp::STT_OBJECT,
1517 elfcpp::STB_LOCAL,
1518 elfcpp::STV_HIDDEN, 0,
1519 false, false);
1520
1521 // If there are any IRELATIVE relocations, they get GOT entries
1522 // in .got.plt after the jump slot entries.
1523 this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1524 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1525 (elfcpp::SHF_ALLOC
1526 | elfcpp::SHF_WRITE),
1527 this->got_irelative_,
1528 got_plt_order, is_got_plt_relro);
1529
1530 // If there are any TLSDESC relocations, they get GOT entries in
1531 // .got.plt after the jump slot and IRELATIVE entries.
1532 this->got_tlsdesc_ = new Output_data_got<64, false>();
1533 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1534 (elfcpp::SHF_ALLOC
1535 | elfcpp::SHF_WRITE),
1536 this->got_tlsdesc_,
1537 got_plt_order, is_got_plt_relro);
1538 }
1539
1540 return this->got_;
1541 }
1542
1543 // Get the dynamic reloc section, creating it if necessary.
1544
1545 template<int size>
1546 typename Target_x86_64<size>::Reloc_section*
1547 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1548 {
1549 if (this->rela_dyn_ == NULL)
1550 {
1551 gold_assert(layout != NULL);
1552 this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1553 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1554 elfcpp::SHF_ALLOC, this->rela_dyn_,
1555 ORDER_DYNAMIC_RELOCS, false);
1556 }
1557 return this->rela_dyn_;
1558 }
1559
1560 // Get the section to use for IRELATIVE relocs, creating it if
1561 // necessary. These go in .rela.dyn, but only after all other dynamic
1562 // relocations. They need to follow the other dynamic relocations so
1563 // that they can refer to global variables initialized by those
1564 // relocs.
1565
1566 template<int size>
1567 typename Target_x86_64<size>::Reloc_section*
1568 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1569 {
1570 if (this->rela_irelative_ == NULL)
1571 {
1572 // Make sure we have already created the dynamic reloc section.
1573 this->rela_dyn_section(layout);
1574 this->rela_irelative_ = new Reloc_section(false);
1575 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1576 elfcpp::SHF_ALLOC, this->rela_irelative_,
1577 ORDER_DYNAMIC_RELOCS, false);
1578 gold_assert(this->rela_dyn_->output_section()
1579 == this->rela_irelative_->output_section());
1580 }
1581 return this->rela_irelative_;
1582 }
1583
1584 // Record a target-specific program property from the .note.gnu.property
1585 // section.
1586 template<int size>
1587 void
1588 Target_x86_64<size>::record_gnu_property(
1589 unsigned int, unsigned int pr_type,
1590 size_t pr_datasz, const unsigned char* pr_data,
1591 const Object* object)
1592 {
1593 uint32_t val = 0;
1594
1595 switch (pr_type)
1596 {
1597 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
1598 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
1599 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
1600 if (pr_datasz != 4)
1601 {
1602 gold_warning(_("%s: corrupt .note.gnu.property section "
1603 "(pr_datasz for property %d is not 4)"),
1604 object->name().c_str(), pr_type);
1605 return;
1606 }
1607 val = elfcpp::Swap<32, false>::readval(pr_data);
1608 break;
1609 default:
1610 gold_warning(_("%s: unknown program property type 0x%x "
1611 "in .note.gnu.property section"),
1612 object->name().c_str(), pr_type);
1613 break;
1614 }
1615
1616 switch (pr_type)
1617 {
1618 case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
1619 this->object_isa_1_used_ |= val;
1620 break;
1621 case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
1622 this->isa_1_needed_ |= val;
1623 break;
1624 case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
1625 // If we see multiple feature props in one object, OR them together.
1626 this->object_feature_1_ |= val;
1627 break;
1628 }
1629 }
1630
1631 // Merge the target-specific program properties from the current object.
1632 template<int size>
1633 void
1634 Target_x86_64<size>::merge_gnu_properties(const Object*)
1635 {
1636 if (this->seen_first_object_)
1637 {
1638 // If any object is missing the ISA_1_USED property, we must omit
1639 // it from the output file.
1640 if (this->object_isa_1_used_ == 0)
1641 this->isa_1_used_ = 0;
1642 else if (this->isa_1_used_ != 0)
1643 this->isa_1_used_ |= this->object_isa_1_used_;
1644 this->feature_1_ &= this->object_feature_1_;
1645 }
1646 else
1647 {
1648 this->isa_1_used_ = this->object_isa_1_used_;
1649 this->feature_1_ = this->object_feature_1_;
1650 this->seen_first_object_ = true;
1651 }
1652 this->object_isa_1_used_ = 0;
1653 this->object_feature_1_ = 0;
1654 }
1655
1656 static inline void
1657 add_property(Layout* layout, unsigned int pr_type, uint32_t val)
1658 {
1659 unsigned char buf[4];
1660 elfcpp::Swap<32, false>::writeval(buf, val);
1661 layout->add_gnu_property(elfcpp::NT_GNU_PROPERTY_TYPE_0, pr_type, 4, buf);
1662 }
1663
1664 // Finalize the target-specific program properties and add them back to
1665 // the layout.
1666 template<int size>
1667 void
1668 Target_x86_64<size>::do_finalize_gnu_properties(Layout* layout) const
1669 {
1670 if (this->isa_1_used_ != 0)
1671 add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_USED,
1672 this->isa_1_used_);
1673 if (this->isa_1_needed_ != 0)
1674 add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED,
1675 this->isa_1_needed_);
1676 if (this->feature_1_ != 0)
1677 add_property(layout, elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND,
1678 this->feature_1_);
1679 }
1680
1681 // Write the first three reserved words of the .got.plt section.
1682 // The remainder of the section is written while writing the PLT
1683 // in Output_data_plt_i386::do_write.
1684
1685 void
1686 Output_data_got_plt_x86_64::do_write(Output_file* of)
1687 {
1688 // The first entry in the GOT is the address of the .dynamic section
1689 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1690 // We saved space for them when we created the section in
1691 // Target_x86_64::got_section.
1692 const off_t got_file_offset = this->offset();
1693 gold_assert(this->data_size() >= 24);
1694 unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1695 Output_section* dynamic = this->layout_->dynamic_section();
1696 uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1697 elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1698 memset(got_view + 8, 0, 16);
1699 of->write_output_view(got_file_offset, 24, got_view);
1700 }
1701
1702 // Initialize the PLT section.
1703
1704 template<int size>
1705 void
1706 Output_data_plt_x86_64<size>::init(Layout* layout)
1707 {
1708 this->rel_ = new Reloc_section(false);
1709 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1710 elfcpp::SHF_ALLOC, this->rel_,
1711 ORDER_DYNAMIC_PLT_RELOCS, false);
1712 }
1713
1714 template<int size>
1715 void
1716 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1717 {
1718 os->set_entsize(this->get_plt_entry_size());
1719 }
1720
1721 // Add an entry to the PLT.
1722
1723 template<int size>
1724 void
1725 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1726 Symbol* gsym)
1727 {
1728 gold_assert(!gsym->has_plt_offset());
1729
1730 unsigned int plt_index;
1731 off_t plt_offset;
1732 section_offset_type got_offset;
1733
1734 unsigned int* pcount;
1735 unsigned int offset;
1736 unsigned int reserved;
1737 Output_section_data_build* got;
1738 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1739 && gsym->can_use_relative_reloc(false))
1740 {
1741 pcount = &this->irelative_count_;
1742 offset = 0;
1743 reserved = 0;
1744 got = this->got_irelative_;
1745 }
1746 else
1747 {
1748 pcount = &this->count_;
1749 offset = 1;
1750 reserved = 3;
1751 got = this->got_plt_;
1752 }
1753
1754 if (!this->is_data_size_valid())
1755 {
1756 // Note that when setting the PLT offset for a non-IRELATIVE
1757 // entry we skip the initial reserved PLT entry.
1758 plt_index = *pcount + offset;
1759 plt_offset = plt_index * this->get_plt_entry_size();
1760
1761 ++*pcount;
1762
1763 got_offset = (plt_index - offset + reserved) * 8;
1764 gold_assert(got_offset == got->current_data_size());
1765
1766 // Every PLT entry needs a GOT entry which points back to the PLT
1767 // entry (this will be changed by the dynamic linker, normally
1768 // lazily when the function is called).
1769 got->set_current_data_size(got_offset + 8);
1770 }
1771 else
1772 {
1773 // FIXME: This is probably not correct for IRELATIVE relocs.
1774
1775 // For incremental updates, find an available slot.
1776 plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1777 this->get_plt_entry_size(), 0);
1778 if (plt_offset == -1)
1779 gold_fallback(_("out of patch space (PLT);"
1780 " relink with --incremental-full"));
1781
1782 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1783 // can be calculated from the PLT index, adjusting for the three
1784 // reserved entries at the beginning of the GOT.
1785 plt_index = plt_offset / this->get_plt_entry_size() - 1;
1786 got_offset = (plt_index - offset + reserved) * 8;
1787 }
1788
1789 gsym->set_plt_offset(plt_offset);
1790
1791 // Every PLT entry needs a reloc.
1792 this->add_relocation(symtab, layout, gsym, got_offset);
1793
1794 // Note that we don't need to save the symbol. The contents of the
1795 // PLT are independent of which symbols are used. The symbols only
1796 // appear in the relocations.
1797 }
1798
1799 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1800 // the PLT offset.
1801
1802 template<int size>
1803 unsigned int
1804 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1805 Symbol_table* symtab,
1806 Layout* layout,
1807 Sized_relobj_file<size, false>* relobj,
1808 unsigned int local_sym_index)
1809 {
1810 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1811 ++this->irelative_count_;
1812
1813 section_offset_type got_offset = this->got_irelative_->current_data_size();
1814
1815 // Every PLT entry needs a GOT entry which points back to the PLT
1816 // entry.
1817 this->got_irelative_->set_current_data_size(got_offset + 8);
1818
1819 // Every PLT entry needs a reloc.
1820 Reloc_section* rela = this->rela_irelative(symtab, layout);
1821 rela->add_symbolless_local_addend(relobj, local_sym_index,
1822 elfcpp::R_X86_64_IRELATIVE,
1823 this->got_irelative_, got_offset, 0);
1824
1825 return plt_offset;
1826 }
1827
1828 // Add the relocation for a PLT entry.
1829
1830 template<int size>
1831 void
1832 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1833 Layout* layout,
1834 Symbol* gsym,
1835 unsigned int got_offset)
1836 {
1837 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1838 && gsym->can_use_relative_reloc(false))
1839 {
1840 Reloc_section* rela = this->rela_irelative(symtab, layout);
1841 rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1842 this->got_irelative_, got_offset, 0);
1843 }
1844 else
1845 {
1846 gsym->set_needs_dynsym_entry();
1847 this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1848 got_offset, 0);
1849 }
1850 }
1851
1852 // Return where the TLSDESC relocations should go, creating it if
1853 // necessary. These follow the JUMP_SLOT relocations.
1854
1855 template<int size>
1856 typename Output_data_plt_x86_64<size>::Reloc_section*
1857 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1858 {
1859 if (this->tlsdesc_rel_ == NULL)
1860 {
1861 this->tlsdesc_rel_ = new Reloc_section(false);
1862 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1863 elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1864 ORDER_DYNAMIC_PLT_RELOCS, false);
1865 gold_assert(this->tlsdesc_rel_->output_section()
1866 == this->rel_->output_section());
1867 }
1868 return this->tlsdesc_rel_;
1869 }
1870
1871 // Return where the IRELATIVE relocations should go in the PLT. These
1872 // follow the JUMP_SLOT and the TLSDESC relocations.
1873
1874 template<int size>
1875 typename Output_data_plt_x86_64<size>::Reloc_section*
1876 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1877 Layout* layout)
1878 {
1879 if (this->irelative_rel_ == NULL)
1880 {
1881 // Make sure we have a place for the TLSDESC relocations, in
1882 // case we see any later on.
1883 this->rela_tlsdesc(layout);
1884 this->irelative_rel_ = new Reloc_section(false);
1885 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1886 elfcpp::SHF_ALLOC, this->irelative_rel_,
1887 ORDER_DYNAMIC_PLT_RELOCS, false);
1888 gold_assert(this->irelative_rel_->output_section()
1889 == this->rel_->output_section());
1890
1891 if (parameters->doing_static_link())
1892 {
1893 // A statically linked executable will only have a .rela.plt
1894 // section to hold R_X86_64_IRELATIVE relocs for
1895 // STT_GNU_IFUNC symbols. The library will use these
1896 // symbols to locate the IRELATIVE relocs at program startup
1897 // time.
1898 symtab->define_in_output_data("__rela_iplt_start", NULL,
1899 Symbol_table::PREDEFINED,
1900 this->irelative_rel_, 0, 0,
1901 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1902 elfcpp::STV_HIDDEN, 0, false, true);
1903 symtab->define_in_output_data("__rela_iplt_end", NULL,
1904 Symbol_table::PREDEFINED,
1905 this->irelative_rel_, 0, 0,
1906 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1907 elfcpp::STV_HIDDEN, 0, true, true);
1908 }
1909 }
1910 return this->irelative_rel_;
1911 }
1912
1913 // Return the PLT address to use for a global symbol.
1914
1915 template<int size>
1916 uint64_t
1917 Output_data_plt_x86_64<size>::do_address_for_global(const Symbol* gsym)
1918 {
1919 uint64_t offset = 0;
1920 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1921 && gsym->can_use_relative_reloc(false))
1922 offset = (this->count_ + 1) * this->get_plt_entry_size();
1923 return this->address() + offset + gsym->plt_offset();
1924 }
1925
1926 // Return the PLT address to use for a local symbol. These are always
1927 // IRELATIVE relocs.
1928
1929 template<int size>
1930 uint64_t
1931 Output_data_plt_x86_64<size>::do_address_for_local(const Relobj* object,
1932 unsigned int r_sym)
1933 {
1934 return (this->address()
1935 + (this->count_ + 1) * this->get_plt_entry_size()
1936 + object->local_plt_offset(r_sym));
1937 }
1938
1939 // Set the final size.
1940 template<int size>
1941 void
1942 Output_data_plt_x86_64<size>::set_final_data_size()
1943 {
1944 // Number of regular and IFUNC PLT entries, plus the first entry.
1945 unsigned int count = this->count_ + this->irelative_count_ + 1;
1946 // Count the TLSDESC entry, if present.
1947 if (this->has_tlsdesc_entry())
1948 ++count;
1949 this->set_data_size(count * this->get_plt_entry_size());
1950 }
1951
1952 // The first entry in the PLT for an executable.
1953
1954 template<int size>
1955 const unsigned char
1956 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1957 {
1958 // From AMD64 ABI Draft 0.98, page 76
1959 0xff, 0x35, // pushq contents of memory address
1960 0, 0, 0, 0, // replaced with address of .got + 8
1961 0xff, 0x25, // jmp indirect
1962 0, 0, 0, 0, // replaced with address of .got + 16
1963 0x90, 0x90, 0x90, 0x90 // noop (x4)
1964 };
1965
1966 template<int size>
1967 void
1968 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1969 unsigned char* pov,
1970 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1971 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1972 {
1973 memcpy(pov, first_plt_entry, plt_entry_size);
1974 // We do a jmp relative to the PC at the end of this instruction.
1975 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1976 (got_address + 8
1977 - (plt_address + 6)));
1978 elfcpp::Swap<32, false>::writeval(pov + 8,
1979 (got_address + 16
1980 - (plt_address + 12)));
1981 }
1982
1983 // Subsequent entries in the PLT for an executable.
1984
1985 template<int size>
1986 const unsigned char
1987 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1988 {
1989 // From AMD64 ABI Draft 0.98, page 76
1990 0xff, 0x25, // jmpq indirect
1991 0, 0, 0, 0, // replaced with address of symbol in .got
1992 0x68, // pushq immediate
1993 0, 0, 0, 0, // replaced with offset into relocation table
1994 0xe9, // jmpq relative
1995 0, 0, 0, 0 // replaced with offset to start of .plt
1996 };
1997
1998 template<int size>
1999 unsigned int
2000 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
2001 unsigned char* pov,
2002 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2003 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2004 unsigned int got_offset,
2005 unsigned int plt_offset,
2006 unsigned int plt_index)
2007 {
2008 // Check PC-relative offset overflow in PLT entry.
2009 uint64_t plt_got_pcrel_offset = (got_address + got_offset
2010 - (plt_address + plt_offset + 6));
2011 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2012 gold_error(_("PC-relative offset overflow in PLT entry %d"),
2013 plt_index + 1);
2014
2015 memcpy(pov, plt_entry, plt_entry_size);
2016 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2017 plt_got_pcrel_offset);
2018
2019 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
2020 elfcpp::Swap<32, false>::writeval(pov + 12,
2021 - (plt_offset + plt_entry_size));
2022
2023 return 6;
2024 }
2025
2026 // The reserved TLSDESC entry in the PLT for an executable.
2027
2028 template<int size>
2029 const unsigned char
2030 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
2031 {
2032 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2033 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2034 0xff, 0x35, // pushq x(%rip)
2035 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2036 0xff, 0x25, // jmpq *y(%rip)
2037 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2038 0x0f, 0x1f, // nop
2039 0x40, 0
2040 };
2041
2042 template<int size>
2043 void
2044 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
2045 unsigned char* pov,
2046 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2047 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2048 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
2049 unsigned int tlsdesc_got_offset,
2050 unsigned int plt_offset)
2051 {
2052 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2053 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2054 (got_address + 8
2055 - (plt_address + plt_offset
2056 + 6)));
2057 elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
2058 (got_base
2059 + tlsdesc_got_offset
2060 - (plt_address + plt_offset
2061 + 12)));
2062 }
2063
2064 // Return the APLT address to use for a global symbol (for -z bndplt).
2065
2066 uint64_t
2067 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol* gsym)
2068 {
2069 uint64_t offset = this->aplt_offset_;
2070 // Convert the PLT offset into an APLT offset.
2071 unsigned int plt_offset = gsym->plt_offset();
2072 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2073 && gsym->can_use_relative_reloc(false))
2074 offset += this->regular_count() * aplt_entry_size;
2075 else
2076 plt_offset -= plt_entry_size;
2077 plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
2078 return this->address() + offset + plt_offset;
2079 }
2080
2081 // Return the PLT address to use for a local symbol. These are always
2082 // IRELATIVE relocs.
2083
2084 uint64_t
2085 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj* object,
2086 unsigned int r_sym)
2087 {
2088 // Convert the PLT offset into an APLT offset.
2089 unsigned int plt_offset = ((object->local_plt_offset(r_sym) - plt_entry_size)
2090 / (plt_entry_size / aplt_entry_size));
2091 return (this->address()
2092 + this->aplt_offset_
2093 + this->regular_count() * aplt_entry_size
2094 + plt_offset);
2095 }
2096
2097 // Set the final size.
2098 void
2099 Output_data_plt_x86_64_bnd::set_final_data_size()
2100 {
2101 // Number of regular and IFUNC PLT entries.
2102 unsigned int count = this->entry_count();
2103 // Count the first entry and the TLSDESC entry, if present.
2104 unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
2105 unsigned int plt_size = (count + extra) * plt_entry_size;
2106 // Offset of the APLT.
2107 this->aplt_offset_ = plt_size;
2108 // Size of the APLT.
2109 plt_size += count * aplt_entry_size;
2110 this->set_data_size(plt_size);
2111 }
2112
2113 // The first entry in the BND PLT.
2114
2115 const unsigned char
2116 Output_data_plt_x86_64_bnd::first_plt_entry[plt_entry_size] =
2117 {
2118 // From AMD64 ABI Draft 0.98, page 76
2119 0xff, 0x35, // pushq contents of memory address
2120 0, 0, 0, 0, // replaced with address of .got + 8
2121 0xf2, 0xff, 0x25, // bnd jmp indirect
2122 0, 0, 0, 0, // replaced with address of .got + 16
2123 0x0f, 0x1f, 0x00 // nop
2124 };
2125
2126 void
2127 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
2128 unsigned char* pov,
2129 elfcpp::Elf_types<64>::Elf_Addr got_address,
2130 elfcpp::Elf_types<64>::Elf_Addr plt_address)
2131 {
2132 memcpy(pov, first_plt_entry, plt_entry_size);
2133 // We do a jmp relative to the PC at the end of this instruction.
2134 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2135 (got_address + 8
2136 - (plt_address + 6)));
2137 elfcpp::Swap<32, false>::writeval(pov + 9,
2138 (got_address + 16
2139 - (plt_address + 13)));
2140 }
2141
2142 // Subsequent entries in the BND PLT.
2143
2144 const unsigned char
2145 Output_data_plt_x86_64_bnd::plt_entry[plt_entry_size] =
2146 {
2147 // From AMD64 ABI Draft 0.99.8, page 139
2148 0x68, // pushq immediate
2149 0, 0, 0, 0, // replaced with offset into relocation table
2150 0xf2, 0xe9, // bnd jmpq relative
2151 0, 0, 0, 0, // replaced with offset to start of .plt
2152 0x0f, 0x1f, 0x44, 0, 0 // nop
2153 };
2154
2155 // Entries in the BND Additional PLT.
2156
2157 const unsigned char
2158 Output_data_plt_x86_64_bnd::aplt_entry[aplt_entry_size] =
2159 {
2160 // From AMD64 ABI Draft 0.99.8, page 139
2161 0xf2, 0xff, 0x25, // bnd jmpq indirect
2162 0, 0, 0, 0, // replaced with address of symbol in .got
2163 0x90, // nop
2164 };
2165
2166 unsigned int
2167 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
2168 unsigned char* pov,
2169 elfcpp::Elf_types<64>::Elf_Addr,
2170 elfcpp::Elf_types<64>::Elf_Addr,
2171 unsigned int,
2172 unsigned int plt_offset,
2173 unsigned int plt_index)
2174 {
2175 memcpy(pov, plt_entry, plt_entry_size);
2176 elfcpp::Swap_unaligned<32, false>::writeval(pov + 1, plt_index);
2177 elfcpp::Swap<32, false>::writeval(pov + 7, -(plt_offset + 11));
2178 return 0;
2179 }
2180
2181 void
2182 Output_data_plt_x86_64_bnd::fill_aplt_entry(
2183 unsigned char* pov,
2184 elfcpp::Elf_types<64>::Elf_Addr got_address,
2185 elfcpp::Elf_types<64>::Elf_Addr plt_address,
2186 unsigned int got_offset,
2187 unsigned int plt_offset,
2188 unsigned int plt_index)
2189 {
2190 // Check PC-relative offset overflow in PLT entry.
2191 uint64_t plt_got_pcrel_offset = (got_address + got_offset
2192 - (plt_address + plt_offset + 7));
2193 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2194 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2195 plt_index + 1);
2196
2197 memcpy(pov, aplt_entry, aplt_entry_size);
2198 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3, plt_got_pcrel_offset);
2199 }
2200
2201 // The reserved TLSDESC entry in the PLT for an executable.
2202
2203 const unsigned char
2204 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry[plt_entry_size] =
2205 {
2206 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2207 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2208 0xff, 0x35, // pushq x(%rip)
2209 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2210 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2211 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2212 0x0f, 0x1f, 0 // nop
2213 };
2214
2215 void
2216 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
2217 unsigned char* pov,
2218 elfcpp::Elf_types<64>::Elf_Addr got_address,
2219 elfcpp::Elf_types<64>::Elf_Addr plt_address,
2220 elfcpp::Elf_types<64>::Elf_Addr got_base,
2221 unsigned int tlsdesc_got_offset,
2222 unsigned int plt_offset)
2223 {
2224 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2225 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2226 (got_address + 8
2227 - (plt_address + plt_offset
2228 + 6)));
2229 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
2230 (got_base
2231 + tlsdesc_got_offset
2232 - (plt_address + plt_offset
2233 + 13)));
2234 }
2235
2236 // Return the APLT address to use for a global symbol (for IBT).
2237
2238 template<int size>
2239 uint64_t
2240 Output_data_plt_x86_64_ibt<size>::do_address_for_global(const Symbol* gsym)
2241 {
2242 uint64_t offset = this->aplt_offset_;
2243 // Convert the PLT offset into an APLT offset.
2244 unsigned int plt_offset = gsym->plt_offset();
2245 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2246 && gsym->can_use_relative_reloc(false))
2247 offset += this->regular_count() * aplt_entry_size;
2248 else
2249 plt_offset -= plt_entry_size;
2250 plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
2251 return this->address() + offset + plt_offset;
2252 }
2253
2254 // Return the PLT address to use for a local symbol. These are always
2255 // IRELATIVE relocs.
2256
2257 template<int size>
2258 uint64_t
2259 Output_data_plt_x86_64_ibt<size>::do_address_for_local(const Relobj* object,
2260 unsigned int r_sym)
2261 {
2262 // Convert the PLT offset into an APLT offset.
2263 unsigned int plt_offset = ((object->local_plt_offset(r_sym) - plt_entry_size)
2264 / (plt_entry_size / aplt_entry_size));
2265 return (this->address()
2266 + this->aplt_offset_
2267 + this->regular_count() * aplt_entry_size
2268 + plt_offset);
2269 }
2270
2271 // Set the final size.
2272
2273 template<int size>
2274 void
2275 Output_data_plt_x86_64_ibt<size>::set_final_data_size()
2276 {
2277 // Number of regular and IFUNC PLT entries.
2278 unsigned int count = this->entry_count();
2279 // Count the first entry and the TLSDESC entry, if present.
2280 unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
2281 unsigned int plt_size = (count + extra) * plt_entry_size;
2282 // Offset of the APLT.
2283 this->aplt_offset_ = plt_size;
2284 // Size of the APLT.
2285 plt_size += count * aplt_entry_size;
2286 this->set_data_size(plt_size);
2287 }
2288
2289 // The first entry in the IBT PLT.
2290
2291 template<>
2292 const unsigned char
2293 Output_data_plt_x86_64_ibt<32>::first_plt_entry[plt_entry_size] =
2294 {
2295 // MPX isn't supported for x32, so we don't need the BND prefix.
2296 // From AMD64 ABI Draft 0.98, page 76
2297 0xff, 0x35, // pushq contents of memory address
2298 0, 0, 0, 0, // replaced with address of .got + 8
2299 0xff, 0x25, // jmp indirect
2300 0, 0, 0, 0, // replaced with address of .got + 16
2301 0x90, 0x90, 0x90, 0x90 // noop (x4)
2302 };
2303
2304 template<>
2305 const unsigned char
2306 Output_data_plt_x86_64_ibt<64>::first_plt_entry[plt_entry_size] =
2307 {
2308 // Use the BND prefix so that IBT is compatible with MPX.
2309 0xff, 0x35, // pushq contents of memory address
2310 0, 0, 0, 0, // replaced with address of .got + 8
2311 0xf2, 0xff, 0x25, // bnd jmp indirect
2312 0, 0, 0, 0, // replaced with address of .got + 16
2313 0x0f, 0x1f, 0x00 // nop
2314 };
2315
2316 template<int size>
2317 void
2318 Output_data_plt_x86_64_ibt<size>::do_fill_first_plt_entry(
2319 unsigned char* pov,
2320 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2321 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
2322 {
2323 // Offsets to the addresses needing relocation.
2324 const unsigned int roff1 = 2;
2325 const unsigned int roff2 = (size == 32) ? 8 : 9;
2326
2327 memcpy(pov, first_plt_entry, plt_entry_size);
2328 // We do a jmp relative to the PC at the end of this instruction.
2329 elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1,
2330 (got_address + 8
2331 - (plt_address + roff1 + 4)));
2332 elfcpp::Swap<32, false>::writeval(pov + roff2,
2333 (got_address + 16
2334 - (plt_address + roff2 + 4)));
2335 }
2336
2337 // Subsequent entries in the IBT PLT.
2338
2339 template<>
2340 const unsigned char
2341 Output_data_plt_x86_64_ibt<32>::plt_entry[plt_entry_size] =
2342 {
2343 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2344 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2345 0x68, // pushq immediate
2346 0, 0, 0, 0, // replaced with offset into relocation table
2347 0xe9, // jmpq relative
2348 0, 0, 0, 0, // replaced with offset to start of .plt
2349 0x90, 0x90 // nop
2350 };
2351
2352 template<>
2353 const unsigned char
2354 Output_data_plt_x86_64_ibt<64>::plt_entry[plt_entry_size] =
2355 {
2356 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2357 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2358 0x68, // pushq immediate
2359 0, 0, 0, 0, // replaced with offset into relocation table
2360 0xf2, 0xe9, // bnd jmpq relative
2361 0, 0, 0, 0, // replaced with offset to start of .plt
2362 0x90 // nop
2363 };
2364
2365 // Entries in the IBT Additional PLT.
2366
2367 template<>
2368 const unsigned char
2369 Output_data_plt_x86_64_ibt<32>::aplt_entry[aplt_entry_size] =
2370 {
2371 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2372 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2373 0xff, 0x25, // jmpq indirect
2374 0, 0, 0, 0, // replaced with address of symbol in .got
2375 0x0f, 0x1f, 0x04, 0x00, // nop
2376 0x90, 0x90 // nop
2377 };
2378
2379 template<>
2380 const unsigned char
2381 Output_data_plt_x86_64_ibt<64>::aplt_entry[aplt_entry_size] =
2382 {
2383 // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2384 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2385 0xf2, 0xff, 0x25, // bnd jmpq indirect
2386 0, 0, 0, 0, // replaced with address of symbol in .got
2387 0x0f, 0x1f, 0x04, 0x00, // nop
2388 0x90, // nop
2389 };
2390
2391 template<int size>
2392 unsigned int
2393 Output_data_plt_x86_64_ibt<size>::do_fill_plt_entry(
2394 unsigned char* pov,
2395 typename elfcpp::Elf_types<size>::Elf_Addr,
2396 typename elfcpp::Elf_types<size>::Elf_Addr,
2397 unsigned int,
2398 unsigned int plt_offset,
2399 unsigned int plt_index)
2400 {
2401 // Offsets to the addresses needing relocation.
2402 const unsigned int roff1 = 5;
2403 const unsigned int roff2 = (size == 32) ? 10 : 11;
2404
2405 memcpy(pov, plt_entry, plt_entry_size);
2406 elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1, plt_index);
2407 elfcpp::Swap<32, false>::writeval(pov + roff2, -(plt_offset + roff2 + 4));
2408 return 0;
2409 }
2410
2411 template<int size>
2412 void
2413 Output_data_plt_x86_64_ibt<size>::fill_aplt_entry(
2414 unsigned char* pov,
2415 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2416 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2417 unsigned int got_offset,
2418 unsigned int plt_offset,
2419 unsigned int plt_index)
2420 {
2421 // Offset to the address needing relocation.
2422 const unsigned int roff = (size == 32) ? 6 : 7;
2423
2424 // Check PC-relative offset overflow in PLT entry.
2425 uint64_t plt_got_pcrel_offset = (got_address + got_offset
2426 - (plt_address + plt_offset + roff + 4));
2427 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2428 gold_error(_("PC-relative offset overflow in APLT entry %d"),
2429 plt_index + 1);
2430
2431 memcpy(pov, aplt_entry, aplt_entry_size);
2432 elfcpp::Swap_unaligned<32, false>::writeval(pov + roff, plt_got_pcrel_offset);
2433 }
2434
2435 // The reserved TLSDESC entry in the IBT PLT for an executable.
2436
2437 template<int size>
2438 const unsigned char
2439 Output_data_plt_x86_64_ibt<size>::tlsdesc_plt_entry[plt_entry_size] =
2440 {
2441 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2442 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2443 0xff, 0x35, // pushq x(%rip)
2444 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
2445 0xf2, 0xff, 0x25, // jmpq *y(%rip)
2446 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
2447 0x0f, 0x1f, 0 // nop
2448 };
2449
2450 template<int size>
2451 void
2452 Output_data_plt_x86_64_ibt<size>::do_fill_tlsdesc_entry(
2453 unsigned char* pov,
2454 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2455 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2456 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
2457 unsigned int tlsdesc_got_offset,
2458 unsigned int plt_offset)
2459 {
2460 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2461 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2462 (got_address + 8
2463 - (plt_address + plt_offset
2464 + 6)));
2465 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
2466 (got_base
2467 + tlsdesc_got_offset
2468 - (plt_address + plt_offset
2469 + 13)));
2470 }
2471
2472 // The .eh_frame unwind information for the PLT.
2473
2474 template<int size>
2475 const unsigned char
2476 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
2477 {
2478 1, // CIE version.
2479 'z', // Augmentation: augmentation size included.
2480 'R', // Augmentation: FDE encoding included.
2481 '\0', // End of augmentation string.
2482 1, // Code alignment factor.
2483 0x78, // Data alignment factor.
2484 16, // Return address column.
2485 1, // Augmentation size.
2486 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
2487 | elfcpp::DW_EH_PE_sdata4),
2488 elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
2489 elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2490 elfcpp::DW_CFA_nop, // Align to 16 bytes.
2491 elfcpp::DW_CFA_nop
2492 };
2493
2494 template<int size>
2495 const unsigned char
2496 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2497 {
2498 0, 0, 0, 0, // Replaced with offset to .plt.
2499 0, 0, 0, 0, // Replaced with size of .plt.
2500 0, // Augmentation size.
2501 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2502 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2503 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2504 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2505 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2506 11, // Block length.
2507 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2508 elfcpp::DW_OP_breg16, 0, // Push %rip.
2509 elfcpp::DW_OP_lit15, // Push 0xf.
2510 elfcpp::DW_OP_and, // & (%rip & 0xf).
2511 elfcpp::DW_OP_lit11, // Push 0xb.
2512 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
2513 elfcpp::DW_OP_lit3, // Push 3.
2514 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
2515 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2516 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2517 elfcpp::DW_CFA_nop,
2518 elfcpp::DW_CFA_nop,
2519 elfcpp::DW_CFA_nop
2520 };
2521
2522 // The .eh_frame unwind information for the BND PLT.
2523 const unsigned char
2524 Output_data_plt_x86_64_bnd::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2525 {
2526 0, 0, 0, 0, // Replaced with offset to .plt.
2527 0, 0, 0, 0, // Replaced with size of .plt.
2528 0, // Augmentation size.
2529 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2530 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2531 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2532 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2533 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2534 11, // Block length.
2535 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2536 elfcpp::DW_OP_breg16, 0, // Push %rip.
2537 elfcpp::DW_OP_lit15, // Push 0xf.
2538 elfcpp::DW_OP_and, // & (%rip & 0xf).
2539 elfcpp::DW_OP_lit5, // Push 5.
2540 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 5)
2541 elfcpp::DW_OP_lit3, // Push 3.
2542 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 5) << 3)
2543 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
2544 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2545 elfcpp::DW_CFA_nop,
2546 elfcpp::DW_CFA_nop,
2547 elfcpp::DW_CFA_nop
2548 };
2549
2550 // The .eh_frame unwind information for the BND PLT.
2551 template<int size>
2552 const unsigned char
2553 Output_data_plt_x86_64_ibt<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2554 {
2555 0, 0, 0, 0, // Replaced with offset to .plt.
2556 0, 0, 0, 0, // Replaced with size of .plt.
2557 0, // Augmentation size.
2558 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2559 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2560 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2561 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2562 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2563 11, // Block length.
2564 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2565 elfcpp::DW_OP_breg16, 0, // Push %rip.
2566 elfcpp::DW_OP_lit15, // Push 0xf.
2567 elfcpp::DW_OP_and, // & (%rip & 0xf).
2568 elfcpp::DW_OP_lit9, // Push 9.
2569 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 9)
2570 elfcpp::DW_OP_lit3, // Push 3.
2571 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 9) << 3)
2572 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=9)<<3)+%rsp+8
2573 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2574 elfcpp::DW_CFA_nop,
2575 elfcpp::DW_CFA_nop,
2576 elfcpp::DW_CFA_nop
2577 };
2578
2579 // Write out the PLT. This uses the hand-coded instructions above,
2580 // and adjusts them as needed. This is specified by the AMD64 ABI.
2581
2582 template<int size>
2583 void
2584 Output_data_plt_x86_64<size>::do_write(Output_file* of)
2585 {
2586 const off_t offset = this->offset();
2587 const section_size_type oview_size =
2588 convert_to_section_size_type(this->data_size());
2589 unsigned char* const oview = of->get_output_view(offset, oview_size);
2590
2591 const off_t got_file_offset = this->got_plt_->offset();
2592 gold_assert(parameters->incremental_update()
2593 || (got_file_offset + this->got_plt_->data_size()
2594 == this->got_irelative_->offset()));
2595 const section_size_type got_size =
2596 convert_to_section_size_type(this->got_plt_->data_size()
2597 + this->got_irelative_->data_size());
2598 unsigned char* const got_view = of->get_output_view(got_file_offset,
2599 got_size);
2600
2601 unsigned char* pov = oview;
2602
2603 // The base address of the .plt section.
2604 typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
2605 // The base address of the .got section.
2606 typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
2607 // The base address of the PLT portion of the .got section,
2608 // which is where the GOT pointer will point, and where the
2609 // three reserved GOT entries are located.
2610 typename elfcpp::Elf_types<size>::Elf_Addr got_address
2611 = this->got_plt_->address();
2612
2613 this->fill_first_plt_entry(pov, got_address, plt_address);
2614 pov += this->get_plt_entry_size();
2615
2616 // The first three entries in the GOT are reserved, and are written
2617 // by Output_data_got_plt_x86_64::do_write.
2618 unsigned char* got_pov = got_view + 24;
2619
2620 unsigned int plt_offset = this->get_plt_entry_size();
2621 unsigned int got_offset = 24;
2622 const unsigned int count = this->count_ + this->irelative_count_;
2623 for (unsigned int plt_index = 0;
2624 plt_index < count;
2625 ++plt_index,
2626 pov += this->get_plt_entry_size(),
2627 got_pov += 8,
2628 plt_offset += this->get_plt_entry_size(),
2629 got_offset += 8)
2630 {
2631 // Set and adjust the PLT entry itself.
2632 unsigned int lazy_offset = this->fill_plt_entry(pov,
2633 got_address, plt_address,
2634 got_offset, plt_offset,
2635 plt_index);
2636
2637 // Set the entry in the GOT.
2638 elfcpp::Swap<64, false>::writeval(got_pov,
2639 plt_address + plt_offset + lazy_offset);
2640 }
2641
2642 if (this->has_tlsdesc_entry())
2643 {
2644 // Set and adjust the reserved TLSDESC PLT entry.
2645 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2646 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2647 tlsdesc_got_offset, plt_offset);
2648 pov += this->get_plt_entry_size();
2649 }
2650
2651 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2652 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2653
2654 of->write_output_view(offset, oview_size, oview);
2655 of->write_output_view(got_file_offset, got_size, got_view);
2656 }
2657
2658 // Write out the BND PLT.
2659
2660 void
2661 Output_data_plt_x86_64_bnd::do_write(Output_file* of)
2662 {
2663 const off_t offset = this->offset();
2664 const section_size_type oview_size =
2665 convert_to_section_size_type(this->data_size());
2666 unsigned char* const oview = of->get_output_view(offset, oview_size);
2667
2668 Output_data_got<64, false>* got = this->got();
2669 Output_data_got_plt_x86_64* got_plt = this->got_plt();
2670 Output_data_space* got_irelative = this->got_irelative();
2671
2672 const off_t got_file_offset = got_plt->offset();
2673 gold_assert(parameters->incremental_update()
2674 || (got_file_offset + got_plt->data_size()
2675 == got_irelative->offset()));
2676 const section_size_type got_size =
2677 convert_to_section_size_type(got_plt->data_size()
2678 + got_irelative->data_size());
2679 unsigned char* const got_view = of->get_output_view(got_file_offset,
2680 got_size);
2681
2682 unsigned char* pov = oview;
2683
2684 // The base address of the .plt section.
2685 elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2686 // The base address of the .got section.
2687 elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2688 // The base address of the PLT portion of the .got section,
2689 // which is where the GOT pointer will point, and where the
2690 // three reserved GOT entries are located.
2691 elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2692
2693 this->fill_first_plt_entry(pov, got_address, plt_address);
2694 pov += plt_entry_size;
2695
2696 // The first three entries in the GOT are reserved, and are written
2697 // by Output_data_got_plt_x86_64::do_write.
2698 unsigned char* got_pov = got_view + 24;
2699
2700 unsigned int plt_offset = plt_entry_size;
2701 unsigned int got_offset = 24;
2702 const unsigned int count = this->entry_count();
2703 for (unsigned int plt_index = 0;
2704 plt_index < count;
2705 ++plt_index,
2706 pov += plt_entry_size,
2707 got_pov += 8,
2708 plt_offset += plt_entry_size,
2709 got_offset += 8)
2710 {
2711 // Set and adjust the PLT entry itself.
2712 unsigned int lazy_offset = this->fill_plt_entry(pov,
2713 got_address, plt_address,
2714 got_offset, plt_offset,
2715 plt_index);
2716
2717 // Set the entry in the GOT.
2718 elfcpp::Swap<64, false>::writeval(got_pov,
2719 plt_address + plt_offset + lazy_offset);
2720 }
2721
2722 if (this->has_tlsdesc_entry())
2723 {
2724 // Set and adjust the reserved TLSDESC PLT entry.
2725 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2726 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2727 tlsdesc_got_offset, plt_offset);
2728 pov += this->get_plt_entry_size();
2729 }
2730
2731 // Write the additional PLT.
2732 got_offset = 24;
2733 for (unsigned int plt_index = 0;
2734 plt_index < count;
2735 ++plt_index,
2736 pov += aplt_entry_size,
2737 plt_offset += aplt_entry_size,
2738 got_offset += 8)
2739 {
2740 // Set and adjust the APLT entry.
2741 this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2742 plt_offset, plt_index);
2743 }
2744
2745 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2746 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2747
2748 of->write_output_view(offset, oview_size, oview);
2749 of->write_output_view(got_file_offset, got_size, got_view);
2750 }
2751
2752 // Write out the IBT PLT.
2753
2754 template<int size>
2755 void
2756 Output_data_plt_x86_64_ibt<size>::do_write(Output_file* of)
2757 {
2758 const off_t offset = this->offset();
2759 const section_size_type oview_size =
2760 convert_to_section_size_type(this->data_size());
2761 unsigned char* const oview = of->get_output_view(offset, oview_size);
2762
2763 Output_data_got<64, false>* got = this->got();
2764 Output_data_got_plt_x86_64* got_plt = this->got_plt();
2765 Output_data_space* got_irelative = this->got_irelative();
2766
2767 const off_t got_file_offset = got_plt->offset();
2768 gold_assert(parameters->incremental_update()
2769 || (got_file_offset + got_plt->data_size()
2770 == got_irelative->offset()));
2771 const section_size_type got_size =
2772 convert_to_section_size_type(got_plt->data_size()
2773 + got_irelative->data_size());
2774 unsigned char* const got_view = of->get_output_view(got_file_offset,
2775 got_size);
2776
2777 unsigned char* pov = oview;
2778
2779 // The base address of the .plt section.
2780 elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2781 // The base address of the .got section.
2782 elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2783 // The base address of the PLT portion of the .got section,
2784 // which is where the GOT pointer will point, and where the
2785 // three reserved GOT entries are located.
2786 elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2787
2788 this->fill_first_plt_entry(pov, got_address, plt_address);
2789 pov += plt_entry_size;
2790
2791 // The first three entries in the GOT are reserved, and are written
2792 // by Output_data_got_plt_x86_64::do_write.
2793 unsigned char* got_pov = got_view + 24;
2794
2795 unsigned int plt_offset = plt_entry_size;
2796 unsigned int got_offset = 24;
2797 const unsigned int count = this->entry_count();
2798 for (unsigned int plt_index = 0;
2799 plt_index < count;
2800 ++plt_index,
2801 pov += plt_entry_size,
2802 got_pov += 8,
2803 plt_offset += plt_entry_size,
2804 got_offset += 8)
2805 {
2806 // Set and adjust the PLT entry itself.
2807 unsigned int lazy_offset = this->fill_plt_entry(pov,
2808 got_address, plt_address,
2809 got_offset, plt_offset,
2810 plt_index);
2811
2812 // Set the entry in the GOT.
2813 elfcpp::Swap<64, false>::writeval(got_pov,
2814 plt_address + plt_offset + lazy_offset);
2815 }
2816
2817 if (this->has_tlsdesc_entry())
2818 {
2819 // Set and adjust the reserved TLSDESC PLT entry.
2820 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2821 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2822 tlsdesc_got_offset, plt_offset);
2823 pov += this->get_plt_entry_size();
2824 }
2825
2826 // Write the additional PLT.
2827 got_offset = 24;
2828 for (unsigned int plt_index = 0;
2829 plt_index < count;
2830 ++plt_index,
2831 pov += aplt_entry_size,
2832 plt_offset += aplt_entry_size,
2833 got_offset += 8)
2834 {
2835 // Set and adjust the APLT entry.
2836 this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2837 plt_offset, plt_index);
2838 }
2839
2840 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2841 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2842
2843 of->write_output_view(offset, oview_size, oview);
2844 of->write_output_view(got_file_offset, got_size, got_view);
2845 }
2846
2847 // Create the PLT section.
2848
2849 template<int size>
2850 void
2851 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
2852 {
2853 if (this->plt_ == NULL)
2854 {
2855 // Create the GOT sections first.
2856 this->got_section(symtab, layout);
2857
2858 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
2859 this->got_irelative_);
2860
2861 // Add unwind information if requested.
2862 if (parameters->options().ld_generated_unwind_info())
2863 this->plt_->add_eh_frame(layout);
2864
2865 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
2866 (elfcpp::SHF_ALLOC
2867 | elfcpp::SHF_EXECINSTR),
2868 this->plt_, ORDER_PLT, false);
2869
2870 // Make the sh_info field of .rela.plt point to .plt.
2871 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
2872 rela_plt_os->set_info_section(this->plt_->output_section());
2873 }
2874 }
2875
2876 template<>
2877 Output_data_plt_x86_64<32>*
2878 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2879 Output_data_got<64, false>* got,
2880 Output_data_got_plt_x86_64* got_plt,
2881 Output_data_space* got_irelative)
2882 {
2883 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2884 return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
2885 got_irelative);
2886 return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2887 got_irelative);
2888 }
2889
2890 template<>
2891 Output_data_plt_x86_64<64>*
2892 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2893 Output_data_got<64, false>* got,
2894 Output_data_got_plt_x86_64* got_plt,
2895 Output_data_space* got_irelative)
2896 {
2897 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2898 return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
2899 got_irelative);
2900 else if (parameters->options().bndplt())
2901 return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2902 got_irelative);
2903 else
2904 return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2905 got_irelative);
2906 }
2907
2908 template<>
2909 Output_data_plt_x86_64<32>*
2910 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2911 Output_data_got<64, false>* got,
2912 Output_data_got_plt_x86_64* got_plt,
2913 Output_data_space* got_irelative,
2914 unsigned int plt_count)
2915 {
2916 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2917 return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
2918 got_irelative, plt_count);
2919 return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2920 got_irelative, plt_count);
2921 }
2922
2923 template<>
2924 Output_data_plt_x86_64<64>*
2925 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2926 Output_data_got<64, false>* got,
2927 Output_data_got_plt_x86_64* got_plt,
2928 Output_data_space* got_irelative,
2929 unsigned int plt_count)
2930 {
2931 if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2932 return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
2933 got_irelative, plt_count);
2934 else if (parameters->options().bndplt())
2935 return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2936 got_irelative, plt_count);
2937 else
2938 return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2939 got_irelative,
2940 plt_count);
2941 }
2942
2943 // Return the section for TLSDESC relocations.
2944
2945 template<int size>
2946 typename Target_x86_64<size>::Reloc_section*
2947 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
2948 {
2949 return this->plt_section()->rela_tlsdesc(layout);
2950 }
2951
2952 // Create a PLT entry for a global symbol.
2953
2954 template<int size>
2955 void
2956 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
2957 Symbol* gsym)
2958 {
2959 if (gsym->has_plt_offset())
2960 return;
2961
2962 if (this->plt_ == NULL)
2963 this->make_plt_section(symtab, layout);
2964
2965 this->plt_->add_entry(symtab, layout, gsym);
2966 }
2967
2968 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
2969
2970 template<int size>
2971 void
2972 Target_x86_64<size>::make_local_ifunc_plt_entry(
2973 Symbol_table* symtab, Layout* layout,
2974 Sized_relobj_file<size, false>* relobj,
2975 unsigned int local_sym_index)
2976 {
2977 if (relobj->local_has_plt_offset(local_sym_index))
2978 return;
2979 if (this->plt_ == NULL)
2980 this->make_plt_section(symtab, layout);
2981 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
2982 relobj,
2983 local_sym_index);
2984 relobj->set_local_plt_offset(local_sym_index, plt_offset);
2985 }
2986
2987 // Return the number of entries in the PLT.
2988
2989 template<int size>
2990 unsigned int
2991 Target_x86_64<size>::plt_entry_count() const
2992 {
2993 if (this->plt_ == NULL)
2994 return 0;
2995 return this->plt_->entry_count();
2996 }
2997
2998 // Return the offset of the first non-reserved PLT entry.
2999
3000 template<int size>
3001 unsigned int
3002 Target_x86_64<size>::first_plt_entry_offset() const
3003 {
3004 if (this->plt_ == NULL)
3005 return 0;
3006 return this->plt_->first_plt_entry_offset();
3007 }
3008
3009 // Return the size of each PLT entry.
3010
3011 template<int size>
3012 unsigned int
3013 Target_x86_64<size>::plt_entry_size() const
3014 {
3015 if (this->plt_ == NULL)
3016 return 0;
3017 return this->plt_->get_plt_entry_size();
3018 }
3019
3020 // Create the GOT and PLT sections for an incremental update.
3021
3022 template<int size>
3023 Output_data_got_base*
3024 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
3025 Layout* layout,
3026 unsigned int got_count,
3027 unsigned int plt_count)
3028 {
3029 gold_assert(this->got_ == NULL);
3030
3031 this->got_ = new Output_data_got<64, false>(got_count * 8);
3032 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3033 (elfcpp::SHF_ALLOC
3034 | elfcpp::SHF_WRITE),
3035 this->got_, ORDER_RELRO_LAST,
3036 true);
3037
3038 // Add the three reserved entries.
3039 this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
3040 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3041 (elfcpp::SHF_ALLOC
3042 | elfcpp::SHF_WRITE),
3043 this->got_plt_, ORDER_NON_RELRO_FIRST,
3044 false);
3045
3046 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3047 this->global_offset_table_ =
3048 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
3049 Symbol_table::PREDEFINED,
3050 this->got_plt_,
3051 0, 0, elfcpp::STT_OBJECT,
3052 elfcpp::STB_LOCAL,
3053 elfcpp::STV_HIDDEN, 0,
3054 false, false);
3055
3056 // If there are any TLSDESC relocations, they get GOT entries in
3057 // .got.plt after the jump slot entries.
3058 // FIXME: Get the count for TLSDESC entries.
3059 this->got_tlsdesc_ = new Output_data_got<64, false>(0);
3060 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3061 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
3062 this->got_tlsdesc_,
3063 ORDER_NON_RELRO_FIRST, false);
3064
3065 // If there are any IRELATIVE relocations, they get GOT entries in
3066 // .got.plt after the jump slot and TLSDESC entries.
3067 this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
3068 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3069 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
3070 this->got_irelative_,
3071 ORDER_NON_RELRO_FIRST, false);
3072
3073 // Create the PLT section.
3074 this->plt_ = this->make_data_plt(layout, this->got_,
3075 this->got_plt_,
3076 this->got_irelative_,
3077 plt_count);
3078
3079 // Add unwind information if requested.
3080 if (parameters->options().ld_generated_unwind_info())
3081 this->plt_->add_eh_frame(layout);
3082
3083 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
3084 elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
3085 this->plt_, ORDER_PLT, false);
3086
3087 // Make the sh_info field of .rela.plt point to .plt.
3088 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
3089 rela_plt_os->set_info_section(this->plt_->output_section());
3090
3091 // Create the rela_dyn section.
3092 this->rela_dyn_section(layout);
3093
3094 return this->got_;
3095 }
3096
3097 // Reserve a GOT entry for a local symbol, and regenerate any
3098 // necessary dynamic relocations.
3099
3100 template<int size>
3101 void
3102 Target_x86_64<size>::reserve_local_got_entry(
3103 unsigned int got_index,
3104 Sized_relobj<size, false>* obj,
3105 unsigned int r_sym,
3106 unsigned int got_type)
3107 {
3108 unsigned int got_offset = got_index * 8;
3109 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
3110
3111 this->got_->reserve_local(got_index, obj, r_sym, got_type);
3112 switch (got_type)
3113 {
3114 case GOT_TYPE_STANDARD:
3115 if (parameters->options().output_is_position_independent())
3116 rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
3117 this->got_, got_offset, 0, false);
3118 break;
3119 case GOT_TYPE_TLS_OFFSET:
3120 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
3121 this->got_, got_offset, 0);
3122 break;
3123 case GOT_TYPE_TLS_PAIR:
3124 this->got_->reserve_slot(got_index + 1);
3125 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
3126 this->got_, got_offset, 0);
3127 break;
3128 case GOT_TYPE_TLS_DESC:
3129 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
3130 // this->got_->reserve_slot(got_index + 1);
3131 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3132 // this->got_, got_offset, 0);
3133 break;
3134 default:
3135 gold_unreachable();
3136 }
3137 }
3138
3139 // Reserve a GOT entry for a global symbol, and regenerate any
3140 // necessary dynamic relocations.
3141
3142 template<int size>
3143 void
3144 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
3145 Symbol* gsym,
3146 unsigned int got_type)
3147 {
3148 unsigned int got_offset = got_index * 8;
3149 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
3150
3151 this->got_->reserve_global(got_index, gsym, got_type);
3152 switch (got_type)
3153 {
3154 case GOT_TYPE_STANDARD:
3155 if (!gsym->final_value_is_known())
3156 {
3157 if (gsym->is_from_dynobj()
3158 || gsym->is_undefined()
3159 || gsym->is_preemptible()
3160 || gsym->type() == elfcpp::STT_GNU_IFUNC)
3161 rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
3162 this->got_, got_offset, 0);
3163 else
3164 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
3165 this->got_, got_offset, 0, false);
3166 }
3167 break;
3168 case GOT_TYPE_TLS_OFFSET:
3169 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
3170 this->got_, got_offset, 0, false);
3171 break;
3172 case GOT_TYPE_TLS_PAIR:
3173 this->got_->reserve_slot(got_index + 1);
3174 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
3175 this->got_, got_offset, 0, false);
3176 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
3177 this->got_, got_offset + 8, 0, false);
3178 break;
3179 case GOT_TYPE_TLS_DESC:
3180 this->got_->reserve_slot(got_index + 1);
3181 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
3182 this->got_, got_offset, 0, false);
3183 break;
3184 default:
3185 gold_unreachable();
3186 }
3187 }
3188
3189 // Register an existing PLT entry for a global symbol.
3190
3191 template<int size>
3192 void
3193 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
3194 Layout* layout,
3195 unsigned int plt_index,
3196 Symbol* gsym)
3197 {
3198 gold_assert(this->plt_ != NULL);
3199 gold_assert(!gsym->has_plt_offset());
3200
3201 this->plt_->reserve_slot(plt_index);
3202
3203 gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
3204
3205 unsigned int got_offset = (plt_index + 3) * 8;
3206 this->plt_->add_relocation(symtab, layout, gsym, got_offset);
3207 }
3208
3209 // Force a COPY relocation for a given symbol.
3210
3211 template<int size>
3212 void
3213 Target_x86_64<size>::emit_copy_reloc(
3214 Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
3215 {
3216 this->copy_relocs_.emit_copy_reloc(symtab,
3217 symtab->get_sized_symbol<size>(sym),
3218 os,
3219 offset,
3220 this->rela_dyn_section(NULL));
3221 }
3222
3223 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
3224
3225 template<int size>
3226 void
3227 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
3228 Layout* layout)
3229 {
3230 if (this->tls_base_symbol_defined_)
3231 return;
3232
3233 Output_segment* tls_segment = layout->tls_segment();
3234 if (tls_segment != NULL)
3235 {
3236 bool is_exec = parameters->options().output_is_executable();
3237 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
3238 Symbol_table::PREDEFINED,
3239 tls_segment, 0, 0,
3240 elfcpp::STT_TLS,
3241 elfcpp::STB_LOCAL,
3242 elfcpp::STV_HIDDEN, 0,
3243 (is_exec
3244 ? Symbol::SEGMENT_END
3245 : Symbol::SEGMENT_START),
3246 true);
3247 }
3248 this->tls_base_symbol_defined_ = true;
3249 }
3250
3251 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
3252
3253 template<int size>
3254 void
3255 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
3256 Layout* layout)
3257 {
3258 if (this->plt_ == NULL)
3259 this->make_plt_section(symtab, layout);
3260
3261 if (!this->plt_->has_tlsdesc_entry())
3262 {
3263 // Allocate the TLSDESC_GOT entry.
3264 Output_data_got<64, false>* got = this->got_section(symtab, layout);
3265 unsigned int got_offset = got->add_constant(0);
3266
3267 // Allocate the TLSDESC_PLT entry.
3268 this->plt_->reserve_tlsdesc_entry(got_offset);
3269 }
3270 }
3271
3272 // Create a GOT entry for the TLS module index.
3273
3274 template<int size>
3275 unsigned int
3276 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
3277 Sized_relobj_file<size, false>* object)
3278 {
3279 if (this->got_mod_index_offset_ == -1U)
3280 {
3281 gold_assert(symtab != NULL && layout != NULL && object != NULL);
3282 Reloc_section* rela_dyn = this->rela_dyn_section(layout);
3283 Output_data_got<64, false>* got = this->got_section(symtab, layout);
3284 unsigned int got_offset = got->add_constant(0);
3285 rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
3286 got_offset, 0);
3287 got->add_constant(0);
3288 this->got_mod_index_offset_ = got_offset;
3289 }
3290 return this->got_mod_index_offset_;
3291 }
3292
3293 // Optimize the TLS relocation type based on what we know about the
3294 // symbol. IS_FINAL is true if the final address of this symbol is
3295 // known at link time.
3296
3297 template<int size>
3298 tls::Tls_optimization
3299 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
3300 {
3301 // If we are generating a shared library, then we can't do anything
3302 // in the linker.
3303 if (parameters->options().shared())
3304 return tls::TLSOPT_NONE;
3305
3306 switch (r_type)
3307 {
3308 case elfcpp::R_X86_64_TLSGD:
3309 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3310 case elfcpp::R_X86_64_TLSDESC_CALL:
3311 // These are General-Dynamic which permits fully general TLS
3312 // access. Since we know that we are generating an executable,
3313 // we can convert this to Initial-Exec. If we also know that
3314 // this is a local symbol, we can further switch to Local-Exec.
3315 if (is_final)
3316 return tls::TLSOPT_TO_LE;
3317 return tls::TLSOPT_TO_IE;
3318
3319 case elfcpp::R_X86_64_TLSLD:
3320 // This is Local-Dynamic, which refers to a local symbol in the
3321 // dynamic TLS block. Since we know that we generating an
3322 // executable, we can switch to Local-Exec.
3323 return tls::TLSOPT_TO_LE;
3324
3325 case elfcpp::R_X86_64_DTPOFF32:
3326 case elfcpp::R_X86_64_DTPOFF64:
3327 // Another Local-Dynamic reloc.
3328 return tls::TLSOPT_TO_LE;
3329
3330 case elfcpp::R_X86_64_GOTTPOFF:
3331 // These are Initial-Exec relocs which get the thread offset
3332 // from the GOT. If we know that we are linking against the
3333 // local symbol, we can switch to Local-Exec, which links the
3334 // thread offset into the instruction.
3335 if (is_final)
3336 return tls::TLSOPT_TO_LE;
3337 return tls::TLSOPT_NONE;
3338
3339 case elfcpp::R_X86_64_TPOFF32:
3340 // When we already have Local-Exec, there is nothing further we
3341 // can do.
3342 return tls::TLSOPT_NONE;
3343
3344 default:
3345 gold_unreachable();
3346 }
3347 }
3348
3349 // Get the Reference_flags for a particular relocation.
3350
3351 template<int size>
3352 int
3353 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
3354 {
3355 switch (r_type)
3356 {
3357 case elfcpp::R_X86_64_NONE:
3358 case elfcpp::R_X86_64_GNU_VTINHERIT:
3359 case elfcpp::R_X86_64_GNU_VTENTRY:
3360 case elfcpp::R_X86_64_GOTPC32:
3361 case elfcpp::R_X86_64_GOTPC64:
3362 // No symbol reference.
3363 return 0;
3364
3365 case elfcpp::R_X86_64_64:
3366 case elfcpp::R_X86_64_32:
3367 case elfcpp::R_X86_64_32S:
3368 case elfcpp::R_X86_64_16:
3369 case elfcpp::R_X86_64_8:
3370 return Symbol::ABSOLUTE_REF;
3371
3372 case elfcpp::R_X86_64_PC64:
3373 case elfcpp::R_X86_64_PC32:
3374 case elfcpp::R_X86_64_PC32_BND:
3375 case elfcpp::R_X86_64_PC16:
3376 case elfcpp::R_X86_64_PC8:
3377 case elfcpp::R_X86_64_GOTOFF64:
3378 return Symbol::RELATIVE_REF;
3379
3380 case elfcpp::R_X86_64_PLT32:
3381 case elfcpp::R_X86_64_PLT32_BND:
3382 case elfcpp::R_X86_64_PLTOFF64:
3383 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
3384
3385 case elfcpp::R_X86_64_GOT64:
3386 case elfcpp::R_X86_64_GOT32:
3387 case elfcpp::R_X86_64_GOTPCREL64:
3388 case elfcpp::R_X86_64_GOTPCREL:
3389 case elfcpp::R_X86_64_GOTPCRELX:
3390 case elfcpp::R_X86_64_REX_GOTPCRELX:
3391 case elfcpp::R_X86_64_GOTPLT64:
3392 // Absolute in GOT.
3393 return Symbol::ABSOLUTE_REF;
3394
3395 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3396 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3397 case elfcpp::R_X86_64_TLSDESC_CALL:
3398 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3399 case elfcpp::R_X86_64_DTPOFF32:
3400 case elfcpp::R_X86_64_DTPOFF64:
3401 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3402 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3403 return Symbol::TLS_REF;
3404
3405 case elfcpp::R_X86_64_COPY:
3406 case elfcpp::R_X86_64_GLOB_DAT:
3407 case elfcpp::R_X86_64_JUMP_SLOT:
3408 case elfcpp::R_X86_64_RELATIVE:
3409 case elfcpp::R_X86_64_IRELATIVE:
3410 case elfcpp::R_X86_64_TPOFF64:
3411 case elfcpp::R_X86_64_DTPMOD64:
3412 case elfcpp::R_X86_64_TLSDESC:
3413 case elfcpp::R_X86_64_SIZE32:
3414 case elfcpp::R_X86_64_SIZE64:
3415 default:
3416 // Not expected. We will give an error later.
3417 return 0;
3418 }
3419 }
3420
3421 // Report an unsupported relocation against a local symbol.
3422
3423 template<int size>
3424 void
3425 Target_x86_64<size>::Scan::unsupported_reloc_local(
3426 Sized_relobj_file<size, false>* object,
3427 unsigned int r_type)
3428 {
3429 gold_error(_("%s: unsupported reloc %u against local symbol"),
3430 object->name().c_str(), r_type);
3431 }
3432
3433 // We are about to emit a dynamic relocation of type R_TYPE. If the
3434 // dynamic linker does not support it, issue an error. The GNU linker
3435 // only issues a non-PIC error for an allocated read-only section.
3436 // Here we know the section is allocated, but we don't know that it is
3437 // read-only. But we check for all the relocation types which the
3438 // glibc dynamic linker supports, so it seems appropriate to issue an
3439 // error even if the section is not read-only. If GSYM is not NULL,
3440 // it is the symbol the relocation is against; if it is NULL, the
3441 // relocation is against a local symbol.
3442
3443 template<int size>
3444 void
3445 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
3446 Symbol* gsym)
3447 {
3448 switch (r_type)
3449 {
3450 // These are the relocation types supported by glibc for x86_64
3451 // which should always work.
3452 case elfcpp::R_X86_64_RELATIVE:
3453 case elfcpp::R_X86_64_IRELATIVE:
3454 case elfcpp::R_X86_64_GLOB_DAT:
3455 case elfcpp::R_X86_64_JUMP_SLOT:
3456 case elfcpp::R_X86_64_DTPMOD64:
3457 case elfcpp::R_X86_64_DTPOFF64:
3458 case elfcpp::R_X86_64_TPOFF64:
3459 case elfcpp::R_X86_64_64:
3460 case elfcpp::R_X86_64_COPY:
3461 return;
3462
3463 // glibc supports these reloc types, but they can overflow.
3464 case elfcpp::R_X86_64_PC32:
3465 case elfcpp::R_X86_64_PC32_BND:
3466 // A PC relative reference is OK against a local symbol or if
3467 // the symbol is defined locally.
3468 if (gsym == NULL
3469 || (!gsym->is_from_dynobj()
3470 && !gsym->is_undefined()
3471 && !gsym->is_preemptible()))
3472 return;
3473 // Fall through.
3474 case elfcpp::R_X86_64_32:
3475 // R_X86_64_32 is OK for x32.
3476 if (size == 32 && r_type == elfcpp::R_X86_64_32)
3477 return;
3478 if (this->issued_non_pic_error_)
3479 return;
3480 gold_assert(parameters->options().output_is_position_independent());
3481 if (gsym == NULL)
3482 object->error(_("requires dynamic R_X86_64_32 reloc which may "
3483 "overflow at runtime; recompile with -fPIC"));
3484 else
3485 {
3486 const char *r_name;
3487 switch (r_type)
3488 {
3489 case elfcpp::R_X86_64_32:
3490 r_name = "R_X86_64_32";
3491 break;
3492 case elfcpp::R_X86_64_PC32:
3493 r_name = "R_X86_64_PC32";
3494 break;
3495 case elfcpp::R_X86_64_PC32_BND:
3496 r_name = "R_X86_64_PC32_BND";
3497 break;
3498 default:
3499 gold_unreachable();
3500 break;
3501 }
3502 object->error(_("requires dynamic %s reloc against '%s' "
3503 "which may overflow at runtime; recompile "
3504 "with -fPIC"),
3505 r_name, gsym->name());
3506 }
3507 this->issued_non_pic_error_ = true;
3508 return;
3509
3510 default:
3511 // This prevents us from issuing more than one error per reloc
3512 // section. But we can still wind up issuing more than one
3513 // error per object file.
3514 if (this->issued_non_pic_error_)
3515 return;
3516 gold_assert(parameters->options().output_is_position_independent());
3517 object->error(_("requires unsupported dynamic reloc %u; "
3518 "recompile with -fPIC"),
3519 r_type);
3520 this->issued_non_pic_error_ = true;
3521 return;
3522
3523 case elfcpp::R_X86_64_NONE:
3524 gold_unreachable();
3525 }
3526 }
3527
3528 // Return whether we need to make a PLT entry for a relocation of the
3529 // given type against a STT_GNU_IFUNC symbol.
3530
3531 template<int size>
3532 bool
3533 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
3534 Sized_relobj_file<size, false>* object,
3535 unsigned int r_type)
3536 {
3537 int flags = Scan::get_reference_flags(r_type);
3538 if (flags & Symbol::TLS_REF)
3539 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
3540 object->name().c_str(), r_type);
3541 return flags != 0;
3542 }
3543
3544 // Scan a relocation for a local symbol.
3545
3546 template<int size>
3547 inline void
3548 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
3549 Layout* layout,
3550 Target_x86_64<size>* target,
3551 Sized_relobj_file<size, false>* object,
3552 unsigned int data_shndx,
3553 Output_section* output_section,
3554 const elfcpp::Rela<size, false>& reloc,
3555 unsigned int r_type,
3556 const elfcpp::Sym<size, false>& lsym,
3557 bool is_discarded)
3558 {
3559 if (is_discarded)
3560 return;
3561
3562 // A local STT_GNU_IFUNC symbol may require a PLT entry.
3563 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
3564 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
3565 {
3566 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3567 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
3568 }
3569
3570 switch (r_type)
3571 {
3572 case elfcpp::R_X86_64_NONE:
3573 case elfcpp::R_X86_64_GNU_VTINHERIT:
3574 case elfcpp::R_X86_64_GNU_VTENTRY:
3575 break;
3576
3577 case elfcpp::R_X86_64_64:
3578 // If building a shared library (or a position-independent
3579 // executable), we need to create a dynamic relocation for this
3580 // location. The relocation applied at link time will apply the
3581 // link-time value, so we flag the location with an
3582 // R_X86_64_RELATIVE relocation so the dynamic loader can
3583 // relocate it easily.
3584 if (parameters->options().output_is_position_independent())
3585 {
3586 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3587 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3588 rela_dyn->add_local_relative(object, r_sym,
3589 (size == 32
3590 ? elfcpp::R_X86_64_RELATIVE64
3591 : elfcpp::R_X86_64_RELATIVE),
3592 output_section, data_shndx,
3593 reloc.get_r_offset(),
3594 reloc.get_r_addend(), is_ifunc);
3595 }
3596 break;
3597
3598 case elfcpp::R_X86_64_32:
3599 case elfcpp::R_X86_64_32S:
3600 case elfcpp::R_X86_64_16:
3601 case elfcpp::R_X86_64_8:
3602 // If building a shared library (or a position-independent
3603 // executable), we need to create a dynamic relocation for this
3604 // location. We can't use an R_X86_64_RELATIVE relocation
3605 // because that is always a 64-bit relocation.
3606 if (parameters->options().output_is_position_independent())
3607 {
3608 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
3609 if (size == 32 && r_type == elfcpp::R_X86_64_32)
3610 {
3611 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3612 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3613 rela_dyn->add_local_relative(object, r_sym,
3614 elfcpp::R_X86_64_RELATIVE,
3615 output_section, data_shndx,
3616 reloc.get_r_offset(),
3617 reloc.get_r_addend(), is_ifunc);
3618 break;
3619 }
3620
3621 this->check_non_pic(object, r_type, NULL);
3622
3623 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3624 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3625 if (lsym.get_st_type() != elfcpp::STT_SECTION)
3626 rela_dyn->add_local(object, r_sym, r_type, output_section,
3627 data_shndx, reloc.get_r_offset(),
3628 reloc.get_r_addend());
3629 else
3630 {
3631 gold_assert(lsym.get_st_value() == 0);
3632 unsigned int shndx = lsym.get_st_shndx();
3633 bool is_ordinary;
3634 shndx = object->adjust_sym_shndx(r_sym, shndx,
3635 &is_ordinary);
3636 if (!is_ordinary)
3637 object->error(_("section symbol %u has bad shndx %u"),
3638 r_sym, shndx);
3639 else
3640 rela_dyn->add_local_section(object, shndx,
3641 r_type, output_section,
3642 data_shndx, reloc.get_r_offset(),
3643 reloc.get_r_addend());
3644 }
3645 }
3646 break;
3647
3648 case elfcpp::R_X86_64_PC64:
3649 case elfcpp::R_X86_64_PC32:
3650 case elfcpp::R_X86_64_PC32_BND:
3651 case elfcpp::R_X86_64_PC16:
3652 case elfcpp::R_X86_64_PC8:
3653 break;
3654
3655 case elfcpp::R_X86_64_PLT32:
3656 case elfcpp::R_X86_64_PLT32_BND:
3657 // Since we know this is a local symbol, we can handle this as a
3658 // PC32 reloc.
3659 break;
3660
3661 case elfcpp::R_X86_64_GOTPC32:
3662 case elfcpp::R_X86_64_GOTOFF64:
3663 case elfcpp::R_X86_64_GOTPC64:
3664 case elfcpp::R_X86_64_PLTOFF64:
3665 // We need a GOT section.
3666 target->got_section(symtab, layout);
3667 // For PLTOFF64, we'd normally want a PLT section, but since we
3668 // know this is a local symbol, no PLT is needed.
3669 break;
3670
3671 case elfcpp::R_X86_64_GOT64:
3672 case elfcpp::R_X86_64_GOT32:
3673 case elfcpp::R_X86_64_GOTPCREL64:
3674 case elfcpp::R_X86_64_GOTPCREL:
3675 case elfcpp::R_X86_64_GOTPCRELX:
3676 case elfcpp::R_X86_64_REX_GOTPCRELX:
3677 case elfcpp::R_X86_64_GOTPLT64:
3678 {
3679 // The symbol requires a GOT section.
3680 Output_data_got<64, false>* got = target->got_section(symtab, layout);
3681
3682 // If the relocation symbol isn't IFUNC,
3683 // and is local, then we will convert
3684 // mov foo@GOTPCREL(%rip), %reg
3685 // to lea foo(%rip), %reg.
3686 // in Relocate::relocate.
3687 if (!parameters->incremental()
3688 && (r_type == elfcpp::R_X86_64_GOTPCREL
3689 || r_type == elfcpp::R_X86_64_GOTPCRELX
3690 || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
3691 && reloc.get_r_offset() >= 2
3692 && !is_ifunc)
3693 {
3694 section_size_type stype;
3695 const unsigned char* view = object->section_contents(data_shndx,
3696 &stype, true);
3697 if (view[reloc.get_r_offset() - 2] == 0x8b)
3698 break;
3699 }
3700
3701 // The symbol requires a GOT entry.
3702 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3703
3704 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
3705 // lets function pointers compare correctly with shared
3706 // libraries. Otherwise we would need an IRELATIVE reloc.
3707 bool is_new;
3708 if (is_ifunc)
3709 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
3710 else
3711 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
3712 if (is_new)
3713 {
3714 // If we are generating a shared object, we need to add a
3715 // dynamic relocation for this symbol's GOT entry.
3716 if (parameters->options().output_is_position_independent())
3717 {
3718 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3719 // R_X86_64_RELATIVE assumes a 64-bit relocation.
3720 if (r_type != elfcpp::R_X86_64_GOT32)
3721 {
3722 unsigned int got_offset =
3723 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
3724 rela_dyn->add_local_relative(object, r_sym,
3725 elfcpp::R_X86_64_RELATIVE,
3726 got, got_offset, 0, is_ifunc);
3727 }
3728 else
3729 {
3730 this->check_non_pic(object, r_type, NULL);
3731
3732 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
3733 rela_dyn->add_local(
3734 object, r_sym, r_type, got,
3735 object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
3736 }
3737 }
3738 }
3739 // For GOTPLT64, we'd normally want a PLT section, but since
3740 // we know this is a local symbol, no PLT is needed.
3741 }
3742 break;
3743
3744 case elfcpp::R_X86_64_COPY:
3745 case elfcpp::R_X86_64_GLOB_DAT:
3746 case elfcpp::R_X86_64_JUMP_SLOT:
3747 case elfcpp::R_X86_64_RELATIVE:
3748 case elfcpp::R_X86_64_IRELATIVE:
3749 // These are outstanding tls relocs, which are unexpected when linking
3750 case elfcpp::R_X86_64_TPOFF64:
3751 case elfcpp::R_X86_64_DTPMOD64:
3752 case elfcpp::R_X86_64_TLSDESC:
3753 gold_error(_("%s: unexpected reloc %u in object file"),
3754 object->name().c_str(), r_type);
3755 break;
3756
3757 // These are initial tls relocs, which are expected when linking
3758 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3759 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3760 case elfcpp::R_X86_64_TLSDESC_CALL:
3761 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3762 case elfcpp::R_X86_64_DTPOFF32:
3763 case elfcpp::R_X86_64_DTPOFF64:
3764 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3765 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3766 {
3767 bool output_is_shared = parameters->options().shared();
3768 const tls::Tls_optimization optimized_type
3769 = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
3770 r_type);
3771 switch (r_type)
3772 {
3773 case elfcpp::R_X86_64_TLSGD: // General-dynamic
3774 if (optimized_type == tls::TLSOPT_NONE)
3775 {
3776 // Create a pair of GOT entries for the module index and
3777 // dtv-relative offset.
3778 Output_data_got<64, false>* got
3779 = target->got_section(symtab, layout);
3780 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3781 unsigned int shndx = lsym.get_st_shndx();
3782 bool is_ordinary;
3783 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
3784 if (!is_ordinary)
3785 object->error(_("local symbol %u has bad shndx %u"),
3786 r_sym, shndx);
3787 else
3788 got->add_local_pair_with_rel(object, r_sym,
3789 shndx,
3790 GOT_TYPE_TLS_PAIR,
3791 target->rela_dyn_section(layout),
3792 elfcpp::R_X86_64_DTPMOD64);
3793 }
3794 else if (optimized_type != tls::TLSOPT_TO_LE)
3795 unsupported_reloc_local(object, r_type);
3796 break;
3797
3798 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3799 target->define_tls_base_symbol(symtab, layout);
3800 if (optimized_type == tls::TLSOPT_NONE)
3801 {
3802 // Create reserved PLT and GOT entries for the resolver.
3803 target->reserve_tlsdesc_entries(symtab, layout);
3804
3805 // Generate a double GOT entry with an
3806 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
3807 // is resolved lazily, so the GOT entry needs to be in
3808 // an area in .got.plt, not .got. Call got_section to
3809 // make sure the section has been created.
3810 target->got_section(symtab, layout);
3811 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3812 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3813 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
3814 {
3815 unsigned int got_offset = got->add_constant(0);
3816 got->add_constant(0);
3817 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
3818 got_offset);
3819 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3820 // We store the arguments we need in a vector, and
3821 // use the index into the vector as the parameter
3822 // to pass to the target specific routines.
3823 uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
3824 void* arg = reinterpret_cast<void*>(intarg);
3825 rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3826 got, got_offset, 0);
3827 }
3828 }
3829 else if (optimized_type != tls::TLSOPT_TO_LE)
3830 unsupported_reloc_local(object, r_type);
3831 break;
3832
3833 case elfcpp::R_X86_64_TLSDESC_CALL:
3834 break;
3835
3836 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3837 if (optimized_type == tls::TLSOPT_NONE)
3838 {
3839 // Create a GOT entry for the module index.
3840 target->got_mod_index_entry(symtab, layout, object);
3841 }
3842 else if (optimized_type != tls::TLSOPT_TO_LE)
3843 unsupported_reloc_local(object, r_type);
3844 break;
3845
3846 case elfcpp::R_X86_64_DTPOFF32:
3847 case elfcpp::R_X86_64_DTPOFF64:
3848 break;
3849
3850 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3851 layout->set_has_static_tls();
3852 if (optimized_type == tls::TLSOPT_NONE)
3853 {
3854 // Create a GOT entry for the tp-relative offset.
3855 Output_data_got<64, false>* got
3856 = target->got_section(symtab, layout);
3857 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3858 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
3859 target->rela_dyn_section(layout),
3860 elfcpp::R_X86_64_TPOFF64);
3861 }
3862 else if (optimized_type != tls::TLSOPT_TO_LE)
3863 unsupported_reloc_local(object, r_type);
3864 break;
3865
3866 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3867 layout->set_has_static_tls();
3868 if (output_is_shared)
3869 unsupported_reloc_local(object, r_type);
3870 break;
3871
3872 default:
3873 gold_unreachable();
3874 }
3875 }
3876 break;
3877
3878 case elfcpp::R_X86_64_SIZE32:
3879 case elfcpp::R_X86_64_SIZE64:
3880 default:
3881 gold_error(_("%s: unsupported reloc %u against local symbol"),
3882 object->name().c_str(), r_type);
3883 break;
3884 }
3885 }
3886
3887
3888 // Report an unsupported relocation against a global symbol.
3889
3890 template<int size>
3891 void
3892 Target_x86_64<size>::Scan::unsupported_reloc_global(
3893 Sized_relobj_file<size, false>* object,
3894 unsigned int r_type,
3895 Symbol* gsym)
3896 {
3897 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3898 object->name().c_str(), r_type, gsym->demangled_name().c_str());
3899 }
3900
3901 // Returns true if this relocation type could be that of a function pointer.
3902 template<int size>
3903 inline bool
3904 Target_x86_64<size>::Scan::possible_function_pointer_reloc(
3905 Sized_relobj_file<size, false>* src_obj,
3906 unsigned int src_indx,
3907 unsigned int r_offset,
3908 unsigned int r_type)
3909 {
3910 switch (r_type)
3911 {
3912 case elfcpp::R_X86_64_64:
3913 case elfcpp::R_X86_64_32:
3914 case elfcpp::R_X86_64_32S:
3915 case elfcpp::R_X86_64_16:
3916 case elfcpp::R_X86_64_8:
3917 case elfcpp::R_X86_64_GOT64:
3918 case elfcpp::R_X86_64_GOT32:
3919 case elfcpp::R_X86_64_GOTPCREL64:
3920 case elfcpp::R_X86_64_GOTPCREL:
3921 case elfcpp::R_X86_64_GOTPCRELX:
3922 case elfcpp::R_X86_64_REX_GOTPCRELX:
3923 case elfcpp::R_X86_64_GOTPLT64:
3924 {
3925 return true;
3926 }
3927 case elfcpp::R_X86_64_PC32:
3928 {
3929 // This relocation may be used both for function calls and
3930 // for taking address of a function. We distinguish between
3931 // them by checking the opcodes.
3932 uint64_t sh_flags = src_obj->section_flags(src_indx);
3933 bool is_executable = (sh_flags & elfcpp::SHF_EXECINSTR) != 0;
3934 if (is_executable)
3935 {
3936 section_size_type stype;
3937 const unsigned char* view = src_obj->section_contents(src_indx,
3938 &stype,
3939 true);
3940
3941 // call
3942 if (r_offset >= 1
3943 && view[r_offset - 1] == 0xe8)
3944 return false;
3945
3946 // jmp
3947 if (r_offset >= 1
3948 && view[r_offset - 1] == 0xe9)
3949 return false;
3950
3951 // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3952 if (r_offset >= 2
3953 && view[r_offset - 2] == 0x0f
3954 && view[r_offset - 1] >= 0x80
3955 && view[r_offset - 1] <= 0x8f)
3956 return false;
3957 }
3958
3959 // Be conservative and treat all others as function pointers.
3960 return true;
3961 }
3962 }
3963 return false;
3964 }
3965
3966 // For safe ICF, scan a relocation for a local symbol to check if it
3967 // corresponds to a function pointer being taken. In that case mark
3968 // the function whose pointer was taken as not foldable.
3969
3970 template<int size>
3971 inline bool
3972 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
3973 Symbol_table* ,
3974 Layout* ,
3975 Target_x86_64<size>* ,
3976 Sized_relobj_file<size, false>* src_obj,
3977 unsigned int src_indx,
3978 Output_section* ,
3979 const elfcpp::Rela<size, false>& reloc,
3980 unsigned int r_type,
3981 const elfcpp::Sym<size, false>&)
3982 {
3983 // When building a shared library, do not fold any local symbols as it is
3984 // not possible to distinguish pointer taken versus a call by looking at
3985 // the relocation types.
3986 if (parameters->options().shared())
3987 return true;
3988
3989 return possible_function_pointer_reloc(src_obj, src_indx,
3990 reloc.get_r_offset(), r_type);
3991 }
3992
3993 // For safe ICF, scan a relocation for a global symbol to check if it
3994 // corresponds to a function pointer being taken. In that case mark
3995 // the function whose pointer was taken as not foldable.
3996
3997 template<int size>
3998 inline bool
3999 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
4000 Symbol_table*,
4001 Layout* ,
4002 Target_x86_64<size>* ,
4003 Sized_relobj_file<size, false>* src_obj,
4004 unsigned int src_indx,
4005 Output_section* ,
4006 const elfcpp::Rela<size, false>& reloc,
4007 unsigned int r_type,
4008 Symbol* gsym)
4009 {
4010 // When building a shared library, do not fold symbols whose visibility
4011 // is hidden, internal or protected.
4012 if (parameters->options().shared()
4013 && (gsym->visibility() == elfcpp::STV_INTERNAL
4014 || gsym->visibility() == elfcpp::STV_PROTECTED
4015 || gsym->visibility() == elfcpp::STV_HIDDEN))
4016 return true;
4017
4018 return possible_function_pointer_reloc(src_obj, src_indx,
4019 reloc.get_r_offset(), r_type);
4020 }
4021
4022 // Scan a relocation for a global symbol.
4023
4024 template<int size>
4025 inline void
4026 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
4027 Layout* layout,
4028 Target_x86_64<size>* target,
4029 Sized_relobj_file<size, false>* object,
4030 unsigned int data_shndx,
4031 Output_section* output_section,
4032 const elfcpp::Rela<size, false>& reloc,
4033 unsigned int r_type,
4034 Symbol* gsym)
4035 {
4036 // A STT_GNU_IFUNC symbol may require a PLT entry.
4037 if (gsym->type() == elfcpp::STT_GNU_IFUNC
4038 && this->reloc_needs_plt_for_ifunc(object, r_type))
4039 target->make_plt_entry(symtab, layout, gsym);
4040
4041 switch (r_type)
4042 {
4043 case elfcpp::R_X86_64_NONE:
4044 case elfcpp::R_X86_64_GNU_VTINHERIT:
4045 case elfcpp::R_X86_64_GNU_VTENTRY:
4046 break;
4047
4048 case elfcpp::R_X86_64_64:
4049 case elfcpp::R_X86_64_32:
4050 case elfcpp::R_X86_64_32S:
4051 case elfcpp::R_X86_64_16:
4052 case elfcpp::R_X86_64_8:
4053 {
4054 // Make a PLT entry if necessary.
4055 if (gsym->needs_plt_entry())
4056 {
4057 target->make_plt_entry(symtab, layout, gsym);
4058 // Since this is not a PC-relative relocation, we may be
4059 // taking the address of a function. In that case we need to
4060 // set the entry in the dynamic symbol table to the address of
4061 // the PLT entry.
4062 if (gsym->is_from_dynobj() && !parameters->options().shared())
4063 gsym->set_needs_dynsym_value();
4064 }
4065 // Make a dynamic relocation if necessary.
4066 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
4067 {
4068 if (!parameters->options().output_is_position_independent()
4069 && gsym->may_need_copy_reloc())
4070 {
4071 target->copy_reloc(symtab, layout, object,
4072 data_shndx, output_section, gsym, reloc);
4073 }
4074 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
4075 || (size == 32 && r_type == elfcpp::R_X86_64_32))
4076 && gsym->type() == elfcpp::STT_GNU_IFUNC
4077 && gsym->can_use_relative_reloc(false)
4078 && !gsym->is_from_dynobj()
4079 && !gsym->is_undefined()
4080 && !gsym->is_preemptible())
4081 {
4082 // Use an IRELATIVE reloc for a locally defined
4083 // STT_GNU_IFUNC symbol. This makes a function
4084 // address in a PIE executable match the address in a
4085 // shared library that it links against.
4086 Reloc_section* rela_dyn =
4087 target->rela_irelative_section(layout);
4088 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
4089 rela_dyn->add_symbolless_global_addend(gsym, r_type,
4090 output_section, object,
4091 data_shndx,
4092 reloc.get_r_offset(),
4093 reloc.get_r_addend());
4094 }
4095 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
4096 || (size == 32 && r_type == elfcpp::R_X86_64_32))
4097 && gsym->can_use_relative_reloc(false))
4098 {
4099 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4100 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
4101 output_section, object,
4102 data_shndx,
4103 reloc.get_r_offset(),
4104 reloc.get_r_addend(), false);
4105 }
4106 else
4107 {
4108 this->check_non_pic(object, r_type, gsym);
4109 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4110 rela_dyn->add_global(gsym, r_type, output_section, object,
4111 data_shndx, reloc.get_r_offset(),
4112 reloc.get_r_addend());
4113 }
4114 }
4115 }
4116 break;
4117
4118 case elfcpp::R_X86_64_PC64:
4119 case elfcpp::R_X86_64_PC32:
4120 case elfcpp::R_X86_64_PC32_BND:
4121 case elfcpp::R_X86_64_PC16:
4122 case elfcpp::R_X86_64_PC8:
4123 {
4124 // Make a PLT entry if necessary.
4125 if (gsym->needs_plt_entry())
4126 target->make_plt_entry(symtab, layout, gsym);
4127 // Make a dynamic relocation if necessary.
4128 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
4129 {
4130 if (parameters->options().output_is_executable()
4131 && gsym->may_need_copy_reloc())
4132 {
4133 target->copy_reloc(symtab, layout, object,
4134 data_shndx, output_section, gsym, reloc);
4135 }
4136 else
4137 {
4138 this->check_non_pic(object, r_type, gsym);
4139 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4140 rela_dyn->add_global(gsym, r_type, output_section, object,
4141 data_shndx, reloc.get_r_offset(),
4142 reloc.get_r_addend());
4143 }
4144 }
4145 }
4146 break;
4147
4148 case elfcpp::R_X86_64_GOT64:
4149 case elfcpp::R_X86_64_GOT32:
4150 case elfcpp::R_X86_64_GOTPCREL64:
4151 case elfcpp::R_X86_64_GOTPCREL:
4152 case elfcpp::R_X86_64_GOTPCRELX:
4153 case elfcpp::R_X86_64_REX_GOTPCRELX:
4154 case elfcpp::R_X86_64_GOTPLT64:
4155 {
4156 // The symbol requires a GOT entry.
4157 Output_data_got<64, false>* got = target->got_section(symtab, layout);
4158
4159 // If we convert this from
4160 // mov foo@GOTPCREL(%rip), %reg
4161 // to lea foo(%rip), %reg.
4162 // OR
4163 // if we convert
4164 // (callq|jmpq) *foo@GOTPCRELX(%rip) to
4165 // (callq|jmpq) foo
4166 // in Relocate::relocate, then there is nothing to do here.
4167 // We cannot make these optimizations in incremental linking mode,
4168 // because we look at the opcode to decide whether or not to make
4169 // change, and during an incremental update, the change may have
4170 // already been applied.
4171
4172 Lazy_view<size> view(object, data_shndx);
4173 size_t r_offset = reloc.get_r_offset();
4174 if (!parameters->incremental()
4175 && r_offset >= 2
4176 && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
4177 r_offset, &view))
4178 break;
4179
4180 if (!parameters->incremental()
4181 && r_offset >= 2
4182 && Target_x86_64<size>::can_convert_callq_to_direct(gsym, r_type,
4183 r_offset,
4184 &view))
4185 break;
4186
4187 if (gsym->final_value_is_known())
4188 {
4189 // For a STT_GNU_IFUNC symbol we want the PLT address.
4190 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
4191 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
4192 else
4193 got->add_global(gsym, GOT_TYPE_STANDARD);
4194 }
4195 else
4196 {
4197 // If this symbol is not fully resolved, we need to add a
4198 // dynamic relocation for it.
4199 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4200
4201 // Use a GLOB_DAT rather than a RELATIVE reloc if:
4202 //
4203 // 1) The symbol may be defined in some other module.
4204 //
4205 // 2) We are building a shared library and this is a
4206 // protected symbol; using GLOB_DAT means that the dynamic
4207 // linker can use the address of the PLT in the main
4208 // executable when appropriate so that function address
4209 // comparisons work.
4210 //
4211 // 3) This is a STT_GNU_IFUNC symbol in position dependent
4212 // code, again so that function address comparisons work.
4213 if (gsym->is_from_dynobj()
4214 || gsym->is_undefined()
4215 || gsym->is_preemptible()
4216 || (gsym->visibility() == elfcpp::STV_PROTECTED
4217 && parameters->options().shared())
4218 || (gsym->type() == elfcpp::STT_GNU_IFUNC
4219 && parameters->options().output_is_position_independent()))
4220 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
4221 elfcpp::R_X86_64_GLOB_DAT);
4222 else
4223 {
4224 // For a STT_GNU_IFUNC symbol we want to write the PLT
4225 // offset into the GOT, so that function pointer
4226 // comparisons work correctly.
4227 bool is_new;
4228 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
4229 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
4230 else
4231 {
4232 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
4233 // Tell the dynamic linker to use the PLT address
4234 // when resolving relocations.
4235 if (gsym->is_from_dynobj()
4236 && !parameters->options().shared())
4237 gsym->set_needs_dynsym_value();
4238 }
4239 if (is_new)
4240 {
4241 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
4242 rela_dyn->add_global_relative(gsym,
4243 elfcpp::R_X86_64_RELATIVE,
4244 got, got_off, 0, false);
4245 }
4246 }
4247 }
4248 }
4249 break;
4250
4251 case elfcpp::R_X86_64_PLT32:
4252 case elfcpp::R_X86_64_PLT32_BND:
4253 // If the symbol is fully resolved, this is just a PC32 reloc.
4254 // Otherwise we need a PLT entry.
4255 if (gsym->final_value_is_known())
4256 break;
4257 // If building a shared library, we can also skip the PLT entry
4258 // if the symbol is defined in the output file and is protected
4259 // or hidden.
4260 if (gsym->is_defined()
4261 && !gsym->is_from_dynobj()
4262 && !gsym->is_preemptible())
4263 break;
4264 target->make_plt_entry(symtab, layout, gsym);
4265 break;
4266
4267 case elfcpp::R_X86_64_GOTPC32:
4268 case elfcpp::R_X86_64_GOTOFF64:
4269 case elfcpp::R_X86_64_GOTPC64:
4270 case elfcpp::R_X86_64_PLTOFF64:
4271 // We need a GOT section.
4272 target->got_section(symtab, layout);
4273 // For PLTOFF64, we also need a PLT entry (but only if the
4274 // symbol is not fully resolved).
4275 if (r_type == elfcpp::R_X86_64_PLTOFF64
4276 && !gsym->final_value_is_known())
4277 target->make_plt_entry(symtab, layout, gsym);
4278 break;
4279
4280 case elfcpp::R_X86_64_COPY:
4281 case elfcpp::R_X86_64_GLOB_DAT:
4282 case elfcpp::R_X86_64_JUMP_SLOT:
4283 case elfcpp::R_X86_64_RELATIVE:
4284 case elfcpp::R_X86_64_IRELATIVE:
4285 // These are outstanding tls relocs, which are unexpected when linking
4286 case elfcpp::R_X86_64_TPOFF64:
4287 case elfcpp::R_X86_64_DTPMOD64:
4288 case elfcpp::R_X86_64_TLSDESC:
4289 gold_error(_("%s: unexpected reloc %u in object file"),
4290 object->name().c_str(), r_type);
4291 break;
4292
4293 // These are initial tls relocs, which are expected for global()
4294 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4295 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4296 case elfcpp::R_X86_64_TLSDESC_CALL:
4297 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4298 case elfcpp::R_X86_64_DTPOFF32:
4299 case elfcpp::R_X86_64_DTPOFF64:
4300 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4301 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4302 {
4303 // For the Initial-Exec model, we can treat undef symbols as final
4304 // when building an executable.
4305 const bool is_final = (gsym->final_value_is_known() ||
4306 (r_type == elfcpp::R_X86_64_GOTTPOFF &&
4307 gsym->is_undefined() &&
4308 parameters->options().output_is_executable()));
4309 const tls::Tls_optimization optimized_type
4310 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
4311 switch (r_type)
4312 {
4313 case elfcpp::R_X86_64_TLSGD: // General-dynamic
4314 if (optimized_type == tls::TLSOPT_NONE)
4315 {
4316 // Create a pair of GOT entries for the module index and
4317 // dtv-relative offset.
4318 Output_data_got<64, false>* got
4319 = target->got_section(symtab, layout);
4320 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
4321 target->rela_dyn_section(layout),
4322 elfcpp::R_X86_64_DTPMOD64,
4323 elfcpp::R_X86_64_DTPOFF64);
4324 }
4325 else if (optimized_type == tls::TLSOPT_TO_IE)
4326 {
4327 // Create a GOT entry for the tp-relative offset.
4328 Output_data_got<64, false>* got
4329 = target->got_section(symtab, layout);
4330 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4331 target->rela_dyn_section(layout),
4332 elfcpp::R_X86_64_TPOFF64);
4333 }
4334 else if (optimized_type != tls::TLSOPT_TO_LE)
4335 unsupported_reloc_global(object, r_type, gsym);
4336 break;
4337
4338 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
4339 target->define_tls_base_symbol(symtab, layout);
4340 if (optimized_type == tls::TLSOPT_NONE)
4341 {
4342 // Create reserved PLT and GOT entries for the resolver.
4343 target->reserve_tlsdesc_entries(symtab, layout);
4344
4345 // Create a double GOT entry with an R_X86_64_TLSDESC
4346 // reloc. The R_X86_64_TLSDESC reloc is resolved
4347 // lazily, so the GOT entry needs to be in an area in
4348 // .got.plt, not .got. Call got_section to make sure
4349 // the section has been created.
4350 target->got_section(symtab, layout);
4351 Output_data_got<64, false>* got = target->got_tlsdesc_section();
4352 Reloc_section* rt = target->rela_tlsdesc_section(layout);
4353 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
4354 elfcpp::R_X86_64_TLSDESC, 0);
4355 }
4356 else if (optimized_type == tls::TLSOPT_TO_IE)
4357 {
4358 // Create a GOT entry for the tp-relative offset.
4359 Output_data_got<64, false>* got
4360 = target->got_section(symtab, layout);
4361 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4362 target->rela_dyn_section(layout),
4363 elfcpp::R_X86_64_TPOFF64);
4364 }
4365 else if (optimized_type != tls::TLSOPT_TO_LE)
4366 unsupported_reloc_global(object, r_type, gsym);
4367 break;
4368
4369 case elfcpp::R_X86_64_TLSDESC_CALL:
4370 break;
4371
4372 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4373 if (optimized_type == tls::TLSOPT_NONE)
4374 {
4375 // Create a GOT entry for the module index.
4376 target->got_mod_index_entry(symtab, layout, object);
4377 }
4378 else if (optimized_type != tls::TLSOPT_TO_LE)
4379 unsupported_reloc_global(object, r_type, gsym);
4380 break;
4381
4382 case elfcpp::R_X86_64_DTPOFF32:
4383 case elfcpp::R_X86_64_DTPOFF64:
4384 break;
4385
4386 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4387 layout->set_has_static_tls();
4388 if (optimized_type == tls::TLSOPT_NONE)
4389 {
4390 // Create a GOT entry for the tp-relative offset.
4391 Output_data_got<64, false>* got
4392 = target->got_section(symtab, layout);
4393 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4394 target->rela_dyn_section(layout),
4395 elfcpp::R_X86_64_TPOFF64);
4396 }
4397 else if (optimized_type != tls::TLSOPT_TO_LE)
4398 unsupported_reloc_global(object, r_type, gsym);
4399 break;
4400
4401 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4402 layout->set_has_static_tls();
4403 if (parameters->options().shared())
4404 unsupported_reloc_global(object, r_type, gsym);
4405 break;
4406
4407 default:
4408 gold_unreachable();
4409 }
4410 }
4411 break;
4412
4413 case elfcpp::R_X86_64_SIZE32:
4414 case elfcpp::R_X86_64_SIZE64:
4415 default:
4416 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
4417 object->name().c_str(), r_type,
4418 gsym->demangled_name().c_str());
4419 break;
4420 }
4421 }
4422
4423 template<int size>
4424 void
4425 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
4426 Layout* layout,
4427 Sized_relobj_file<size, false>* object,
4428 unsigned int data_shndx,
4429 unsigned int sh_type,
4430 const unsigned char* prelocs,
4431 size_t reloc_count,
4432 Output_section* output_section,
4433 bool needs_special_offset_handling,
4434 size_t local_symbol_count,
4435 const unsigned char* plocal_symbols)
4436 {
4437 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4438 Classify_reloc;
4439
4440 if (sh_type == elfcpp::SHT_REL)
4441 {
4442 return;
4443 }
4444
4445 gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
4446 Classify_reloc>(
4447 symtab,
4448 layout,
4449 this,
4450 object,
4451 data_shndx,
4452 prelocs,
4453 reloc_count,
4454 output_section,
4455 needs_special_offset_handling,
4456 local_symbol_count,
4457 plocal_symbols);
4458
4459 }
4460 // Scan relocations for a section.
4461
4462 template<int size>
4463 void
4464 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
4465 Layout* layout,
4466 Sized_relobj_file<size, false>* object,
4467 unsigned int data_shndx,
4468 unsigned int sh_type,
4469 const unsigned char* prelocs,
4470 size_t reloc_count,
4471 Output_section* output_section,
4472 bool needs_special_offset_handling,
4473 size_t local_symbol_count,
4474 const unsigned char* plocal_symbols)
4475 {
4476 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4477 Classify_reloc;
4478
4479 if (sh_type == elfcpp::SHT_REL)
4480 {
4481 gold_error(_("%s: unsupported REL reloc section"),
4482 object->name().c_str());
4483 return;
4484 }
4485
4486 gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
4487 symtab,
4488 layout,
4489 this,
4490 object,
4491 data_shndx,
4492 prelocs,
4493 reloc_count,
4494 output_section,
4495 needs_special_offset_handling,
4496 local_symbol_count,
4497 plocal_symbols);
4498 }
4499
4500 // Finalize the sections.
4501
4502 template<int size>
4503 void
4504 Target_x86_64<size>::do_finalize_sections(
4505 Layout* layout,
4506 const Input_objects*,
4507 Symbol_table* symtab)
4508 {
4509 const Reloc_section* rel_plt = (this->plt_ == NULL
4510 ? NULL
4511 : this->plt_->rela_plt());
4512 layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
4513 this->rela_dyn_, true, false);
4514
4515 // Fill in some more dynamic tags.
4516 Output_data_dynamic* const odyn = layout->dynamic_data();
4517 if (odyn != NULL)
4518 {
4519 if (this->plt_ != NULL
4520 && this->plt_->output_section() != NULL
4521 && this->plt_->has_tlsdesc_entry())
4522 {
4523 unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
4524 unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
4525 this->got_->finalize_data_size();
4526 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
4527 this->plt_, plt_offset);
4528 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
4529 this->got_, got_offset);
4530 }
4531 }
4532
4533 // Emit any relocs we saved in an attempt to avoid generating COPY
4534 // relocs.
4535 if (this->copy_relocs_.any_saved_relocs())
4536 this->copy_relocs_.emit(this->rela_dyn_section(layout));
4537
4538 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
4539 // the .got.plt section.
4540 Symbol* sym = this->global_offset_table_;
4541 if (sym != NULL)
4542 {
4543 uint64_t data_size = this->got_plt_->current_data_size();
4544 symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
4545 }
4546
4547 if (parameters->doing_static_link()
4548 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
4549 {
4550 // If linking statically, make sure that the __rela_iplt symbols
4551 // were defined if necessary, even if we didn't create a PLT.
4552 static const Define_symbol_in_segment syms[] =
4553 {
4554 {
4555 "__rela_iplt_start", // name
4556 elfcpp::PT_LOAD, // segment_type
4557 elfcpp::PF_W, // segment_flags_set
4558 elfcpp::PF(0), // segment_flags_clear
4559 0, // value
4560 0, // size
4561 elfcpp::STT_NOTYPE, // type
4562 elfcpp::STB_GLOBAL, // binding
4563 elfcpp::STV_HIDDEN, // visibility
4564 0, // nonvis
4565 Symbol::SEGMENT_START, // offset_from_base
4566 true // only_if_ref
4567 },
4568 {
4569 "__rela_iplt_end", // name
4570 elfcpp::PT_LOAD, // segment_type
4571 elfcpp::PF_W, // segment_flags_set
4572 elfcpp::PF(0), // segment_flags_clear
4573 0, // value
4574 0, // size
4575 elfcpp::STT_NOTYPE, // type
4576 elfcpp::STB_GLOBAL, // binding
4577 elfcpp::STV_HIDDEN, // visibility
4578 0, // nonvis
4579 Symbol::SEGMENT_START, // offset_from_base
4580 true // only_if_ref
4581 }
4582 };
4583
4584 symtab->define_symbols(layout, 2, syms,
4585 layout->script_options()->saw_sections_clause());
4586 }
4587 }
4588
4589 // For x32, we need to handle PC-relative relocations using full 64-bit
4590 // arithmetic, so that we can detect relocation overflows properly.
4591 // This class overrides the pcrela32_check methods from the defaults in
4592 // Relocate_functions in reloc.h.
4593
4594 template<int size>
4595 class X86_64_relocate_functions : public Relocate_functions<size, false>
4596 {
4597 public:
4598 typedef Relocate_functions<size, false> Base;
4599
4600 // Do a simple PC relative relocation with the addend in the
4601 // relocation.
4602 static inline typename Base::Reloc_status
4603 pcrela32_check(unsigned char* view,
4604 typename elfcpp::Elf_types<64>::Elf_Addr value,
4605 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
4606 typename elfcpp::Elf_types<64>::Elf_Addr address)
4607 {
4608 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4609 Valtype* wv = reinterpret_cast<Valtype*>(view);
4610 value = value + addend - address;
4611 elfcpp::Swap<32, false>::writeval(wv, value);
4612 return (Bits<32>::has_overflow(value)
4613 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4614 }
4615
4616 // Do a simple PC relative relocation with a Symbol_value with the
4617 // addend in the relocation.
4618 static inline typename Base::Reloc_status
4619 pcrela32_check(unsigned char* view,
4620 const Sized_relobj_file<size, false>* object,
4621 const Symbol_value<size>* psymval,
4622 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
4623 typename elfcpp::Elf_types<64>::Elf_Addr address)
4624 {
4625 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4626 Valtype* wv = reinterpret_cast<Valtype*>(view);
4627 typename elfcpp::Elf_types<64>::Elf_Addr value;
4628 if (addend >= 0)
4629 value = psymval->value(object, addend);
4630 else
4631 {
4632 // For negative addends, get the symbol value without
4633 // the addend, then add the addend using 64-bit arithmetic.
4634 value = psymval->value(object, 0);
4635 value += addend;
4636 }
4637 value -= address;
4638 elfcpp::Swap<32, false>::writeval(wv, value);
4639 return (Bits<32>::has_overflow(value)
4640 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4641 }
4642 };
4643
4644 // Perform a relocation.
4645
4646 template<int size>
4647 inline bool
4648 Target_x86_64<size>::Relocate::relocate(
4649 const Relocate_info<size, false>* relinfo,
4650 unsigned int,
4651 Target_x86_64<size>* target,
4652 Output_section*,
4653 size_t relnum,
4654 const unsigned char* preloc,
4655 const Sized_symbol<size>* gsym,
4656 const Symbol_value<size>* psymval,
4657 unsigned char* view,
4658 typename elfcpp::Elf_types<size>::Elf_Addr address,
4659 section_size_type view_size)
4660 {
4661 typedef X86_64_relocate_functions<size> Reloc_funcs;
4662 const elfcpp::Rela<size, false> rela(preloc);
4663 unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
4664
4665 if (this->skip_call_tls_get_addr_)
4666 {
4667 if ((r_type != elfcpp::R_X86_64_PLT32
4668 && r_type != elfcpp::R_X86_64_GOTPCREL
4669 && r_type != elfcpp::R_X86_64_GOTPCRELX
4670 && r_type != elfcpp::R_X86_64_PLT32_BND
4671 && r_type != elfcpp::R_X86_64_PC32_BND
4672 && r_type != elfcpp::R_X86_64_PC32)
4673 || gsym == NULL
4674 || strcmp(gsym->name(), "__tls_get_addr") != 0)
4675 {
4676 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4677 _("missing expected TLS relocation"));
4678 this->skip_call_tls_get_addr_ = false;
4679 }
4680 else
4681 {
4682 this->skip_call_tls_get_addr_ = false;
4683 return false;
4684 }
4685 }
4686
4687 if (view == NULL)
4688 return true;
4689
4690 const Sized_relobj_file<size, false>* object = relinfo->object;
4691
4692 // Pick the value to use for symbols defined in the PLT.
4693 Symbol_value<size> symval;
4694 if (gsym != NULL
4695 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
4696 {
4697 symval.set_output_value(target->plt_address_for_global(gsym));
4698 psymval = &symval;
4699 }
4700 else if (gsym == NULL && psymval->is_ifunc_symbol())
4701 {
4702 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4703 if (object->local_has_plt_offset(r_sym))
4704 {
4705 symval.set_output_value(target->plt_address_for_local(object, r_sym));
4706 psymval = &symval;
4707 }
4708 }
4709
4710 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4711
4712 // Get the GOT offset if needed.
4713 // The GOT pointer points to the end of the GOT section.
4714 // We need to subtract the size of the GOT section to get
4715 // the actual offset to use in the relocation.
4716 bool have_got_offset = false;
4717 // Since the actual offset is always negative, we use signed int to
4718 // support 64-bit GOT relocations.
4719 int got_offset = 0;
4720 switch (r_type)
4721 {
4722 case elfcpp::R_X86_64_GOT32:
4723 case elfcpp::R_X86_64_GOT64:
4724 case elfcpp::R_X86_64_GOTPLT64:
4725 case elfcpp::R_X86_64_GOTPCREL64:
4726 if (gsym != NULL)
4727 {
4728 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4729 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
4730 }
4731 else
4732 {
4733 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4734 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
4735 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4736 - target->got_size());
4737 }
4738 have_got_offset = true;
4739 break;
4740
4741 default:
4742 break;
4743 }
4744
4745 typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
4746
4747 switch (r_type)
4748 {
4749 case elfcpp::R_X86_64_NONE:
4750 case elfcpp::R_X86_64_GNU_VTINHERIT:
4751 case elfcpp::R_X86_64_GNU_VTENTRY:
4752 break;
4753
4754 case elfcpp::R_X86_64_64:
4755 Reloc_funcs::rela64(view, object, psymval, addend);
4756 break;
4757
4758 case elfcpp::R_X86_64_PC64:
4759 Reloc_funcs::pcrela64(view, object, psymval, addend,
4760 address);
4761 break;
4762
4763 case elfcpp::R_X86_64_32:
4764 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4765 Reloc_funcs::CHECK_UNSIGNED);
4766 break;
4767
4768 case elfcpp::R_X86_64_32S:
4769 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4770 Reloc_funcs::CHECK_SIGNED);
4771 break;
4772
4773 case elfcpp::R_X86_64_PC32:
4774 case elfcpp::R_X86_64_PC32_BND:
4775 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4776 address);
4777 break;
4778
4779 case elfcpp::R_X86_64_16:
4780 Reloc_funcs::rela16(view, object, psymval, addend);
4781 break;
4782
4783 case elfcpp::R_X86_64_PC16:
4784 Reloc_funcs::pcrela16(view, object, psymval, addend, address);
4785 break;
4786
4787 case elfcpp::R_X86_64_8:
4788 Reloc_funcs::rela8(view, object, psymval, addend);
4789 break;
4790
4791 case elfcpp::R_X86_64_PC8:
4792 Reloc_funcs::pcrela8(view, object, psymval, addend, address);
4793 break;
4794
4795 case elfcpp::R_X86_64_PLT32:
4796 case elfcpp::R_X86_64_PLT32_BND:
4797 gold_assert(gsym == NULL
4798 || gsym->has_plt_offset()
4799 || gsym->final_value_is_known()
4800 || (gsym->is_defined()
4801 && !gsym->is_from_dynobj()
4802 && !gsym->is_preemptible()));
4803 // Note: while this code looks the same as for R_X86_64_PC32, it
4804 // behaves differently because psymval was set to point to
4805 // the PLT entry, rather than the symbol, in Scan::global().
4806 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4807 address);
4808 break;
4809
4810 case elfcpp::R_X86_64_PLTOFF64:
4811 {
4812 gold_assert(gsym);
4813 gold_assert(gsym->has_plt_offset()
4814 || gsym->final_value_is_known());
4815 typename elfcpp::Elf_types<size>::Elf_Addr got_address;
4816 // This is the address of GLOBAL_OFFSET_TABLE.
4817 got_address = target->got_plt_section()->address();
4818 Reloc_funcs::rela64(view, object, psymval, addend - got_address);
4819 }
4820 break;
4821
4822 case elfcpp::R_X86_64_GOT32:
4823 gold_assert(have_got_offset);
4824 Reloc_funcs::rela32(view, got_offset, addend);
4825 break;
4826
4827 case elfcpp::R_X86_64_GOTPC32:
4828 {
4829 gold_assert(gsym);
4830 typename elfcpp::Elf_types<size>::Elf_Addr value;
4831 value = target->got_plt_section()->address();
4832 Reloc_funcs::pcrela32_check(view, value, addend, address);
4833 }
4834 break;
4835
4836 case elfcpp::R_X86_64_GOT64:
4837 case elfcpp::R_X86_64_GOTPLT64:
4838 // R_X86_64_GOTPLT64 is obsolete and treated the same as
4839 // GOT64.
4840 gold_assert(have_got_offset);
4841 Reloc_funcs::rela64(view, got_offset, addend);
4842 break;
4843
4844 case elfcpp::R_X86_64_GOTPC64:
4845 {
4846 gold_assert(gsym);
4847 typename elfcpp::Elf_types<size>::Elf_Addr value;
4848 value = target->got_plt_section()->address();
4849 Reloc_funcs::pcrela64(view, value, addend, address);
4850 }
4851 break;
4852
4853 case elfcpp::R_X86_64_GOTOFF64:
4854 {
4855 typename elfcpp::Elf_types<size>::Elf_Addr value;
4856 value = (psymval->value(object, 0)
4857 - target->got_plt_section()->address());
4858 Reloc_funcs::rela64(view, value, addend);
4859 }
4860 break;
4861
4862 case elfcpp::R_X86_64_GOTPCREL:
4863 case elfcpp::R_X86_64_GOTPCRELX:
4864 case elfcpp::R_X86_64_REX_GOTPCRELX:
4865 {
4866 // Convert
4867 // mov foo@GOTPCREL(%rip), %reg
4868 // to lea foo(%rip), %reg.
4869 // if possible.
4870 if (!parameters->incremental()
4871 && ((gsym == NULL
4872 && rela.get_r_offset() >= 2
4873 && view[-2] == 0x8b
4874 && !psymval->is_ifunc_symbol())
4875 || (gsym != NULL
4876 && rela.get_r_offset() >= 2
4877 && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
4878 0, &view))))
4879 {
4880 view[-2] = 0x8d;
4881 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4882 }
4883 // Convert
4884 // callq *foo@GOTPCRELX(%rip) to
4885 // addr32 callq foo
4886 // and jmpq *foo@GOTPCRELX(%rip) to
4887 // jmpq foo
4888 // nop
4889 else if (!parameters->incremental()
4890 && gsym != NULL
4891 && rela.get_r_offset() >= 2
4892 && Target_x86_64<size>::can_convert_callq_to_direct(gsym,
4893 r_type,
4894 0, &view))
4895 {
4896 if (view[-1] == 0x15)
4897 {
4898 // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4899 // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
4900 view[-2] = 0x67;
4901 view[-1] = 0xe8;
4902 // Convert GOTPCRELX to 32-bit pc relative reloc.
4903 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4904 }
4905 else
4906 {
4907 // Convert jmpq *foo@GOTPCRELX(%rip) to
4908 // jmpq foo
4909 // nop
4910 // The opcode of direct jmpq is 0xe9.
4911 view[-2] = 0xe9;
4912 // The opcode of nop is 0x90.
4913 view[3] = 0x90;
4914 // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
4915 // relative and since the instruction following the jmpq is now
4916 // the nop, offset the address by 1 byte. The start of the
4917 // relocation also moves ahead by 1 byte.
4918 Reloc_funcs::pcrela32(&view[-1], object, psymval, addend,
4919 address - 1);
4920 }
4921 }
4922 else
4923 {
4924 if (gsym != NULL)
4925 {
4926 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4927 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
4928 - target->got_size());
4929 }
4930 else
4931 {
4932 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4933 gold_assert(object->local_has_got_offset(r_sym,
4934 GOT_TYPE_STANDARD));
4935 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4936 - target->got_size());
4937 }
4938 typename elfcpp::Elf_types<size>::Elf_Addr value;
4939 value = target->got_plt_section()->address() + got_offset;
4940 Reloc_funcs::pcrela32_check(view, value, addend, address);
4941 }
4942 }
4943 break;
4944
4945 case elfcpp::R_X86_64_GOTPCREL64:
4946 {
4947 gold_assert(have_got_offset);
4948 typename elfcpp::Elf_types<size>::Elf_Addr value;
4949 value = target->got_plt_section()->address() + got_offset;
4950 Reloc_funcs::pcrela64(view, value, addend, address);
4951 }
4952 break;
4953
4954 case elfcpp::R_X86_64_COPY:
4955 case elfcpp::R_X86_64_GLOB_DAT:
4956 case elfcpp::R_X86_64_JUMP_SLOT:
4957 case elfcpp::R_X86_64_RELATIVE:
4958 case elfcpp::R_X86_64_IRELATIVE:
4959 // These are outstanding tls relocs, which are unexpected when linking
4960 case elfcpp::R_X86_64_TPOFF64:
4961 case elfcpp::R_X86_64_DTPMOD64:
4962 case elfcpp::R_X86_64_TLSDESC:
4963 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4964 _("unexpected reloc %u in object file"),
4965 r_type);
4966 break;
4967
4968 // These are initial tls relocs, which are expected when linking
4969 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4970 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4971 case elfcpp::R_X86_64_TLSDESC_CALL:
4972 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4973 case elfcpp::R_X86_64_DTPOFF32:
4974 case elfcpp::R_X86_64_DTPOFF64:
4975 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4976 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4977 this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
4978 view, address, view_size);
4979 break;
4980
4981 case elfcpp::R_X86_64_SIZE32:
4982 case elfcpp::R_X86_64_SIZE64:
4983 default:
4984 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4985 _("unsupported reloc %u"),
4986 r_type);
4987 break;
4988 }
4989
4990 if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
4991 {
4992 if (gsym == NULL)
4993 {
4994 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4995 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4996 _("relocation overflow: "
4997 "reference to local symbol %u in %s"),
4998 r_sym, object->name().c_str());
4999 }
5000 else if (gsym->is_defined() && gsym->source() == Symbol::FROM_OBJECT)
5001 {
5002 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5003 _("relocation overflow: "
5004 "reference to '%s' defined in %s"),
5005 gsym->name(),
5006 gsym->object()->name().c_str());
5007 }
5008 else
5009 {
5010 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5011 _("relocation overflow: reference to '%s'"),
5012 gsym->name());
5013 }
5014 }
5015
5016 return true;
5017 }
5018
5019 // Perform a TLS relocation.
5020
5021 template<int size>
5022 inline void
5023 Target_x86_64<size>::Relocate::relocate_tls(
5024 const Relocate_info<size, false>* relinfo,
5025 Target_x86_64<size>* target,
5026 size_t relnum,
5027 const elfcpp::Rela<size, false>& rela,
5028 unsigned int r_type,
5029 const Sized_symbol<size>* gsym,
5030 const Symbol_value<size>* psymval,
5031 unsigned char* view,
5032 typename elfcpp::Elf_types<size>::Elf_Addr address,
5033 section_size_type view_size)
5034 {
5035 Output_segment* tls_segment = relinfo->layout->tls_segment();
5036
5037 const Sized_relobj_file<size, false>* object = relinfo->object;
5038 const elfcpp::Elf_Xword addend = rela.get_r_addend();
5039 elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
5040 bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
5041
5042 typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
5043
5044 const bool is_final = (gsym == NULL
5045 ? !parameters->options().shared()
5046 : gsym->final_value_is_known());
5047 tls::Tls_optimization optimized_type
5048 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
5049 switch (r_type)
5050 {
5051 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
5052 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5053 {
5054 // If this code sequence is used in a non-executable section,
5055 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
5056 // on the assumption that it's being used by itself in a debug
5057 // section. Therefore, in the unlikely event that the code
5058 // sequence appears in a non-executable section, we simply
5059 // leave it unoptimized.
5060 optimized_type = tls::TLSOPT_NONE;
5061 }
5062 if (optimized_type == tls::TLSOPT_TO_LE)
5063 {
5064 if (tls_segment == NULL)
5065 {
5066 gold_assert(parameters->errors()->error_count() > 0
5067 || issue_undefined_symbol_error(gsym));
5068 return;
5069 }
5070 this->tls_gd_to_le(relinfo, relnum, tls_segment,
5071 rela, r_type, value, view,
5072 view_size);
5073 break;
5074 }
5075 else
5076 {
5077 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
5078 ? GOT_TYPE_TLS_OFFSET
5079 : GOT_TYPE_TLS_PAIR);
5080 unsigned int got_offset;
5081 if (gsym != NULL)
5082 {
5083 gold_assert(gsym->has_got_offset(got_type));
5084 got_offset = gsym->got_offset(got_type) - target->got_size();
5085 }
5086 else
5087 {
5088 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5089 gold_assert(object->local_has_got_offset(r_sym, got_type));
5090 got_offset = (object->local_got_offset(r_sym, got_type)
5091 - target->got_size());
5092 }
5093 if (optimized_type == tls::TLSOPT_TO_IE)
5094 {
5095 value = target->got_plt_section()->address() + got_offset;
5096 this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
5097 value, view, address, view_size);
5098 break;
5099 }
5100 else if (optimized_type == tls::TLSOPT_NONE)
5101 {
5102 // Relocate the field with the offset of the pair of GOT
5103 // entries.
5104 value = target->got_plt_section()->address() + got_offset;
5105 Relocate_functions<size, false>::pcrela32(view, value, addend,
5106 address);
5107 break;
5108 }
5109 }
5110 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5111 _("unsupported reloc %u"), r_type);
5112 break;
5113
5114 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
5115 case elfcpp::R_X86_64_TLSDESC_CALL:
5116 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5117 {
5118 // See above comment for R_X86_64_TLSGD.
5119 optimized_type = tls::TLSOPT_NONE;
5120 }
5121 if (optimized_type == tls::TLSOPT_TO_LE)
5122 {
5123 if (tls_segment == NULL)
5124 {
5125 gold_assert(parameters->errors()->error_count() > 0
5126 || issue_undefined_symbol_error(gsym));
5127 return;
5128 }
5129 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
5130 rela, r_type, value, view,
5131 view_size);
5132 break;
5133 }
5134 else
5135 {
5136 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
5137 ? GOT_TYPE_TLS_OFFSET
5138 : GOT_TYPE_TLS_DESC);
5139 unsigned int got_offset = 0;
5140 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
5141 && optimized_type == tls::TLSOPT_NONE)
5142 {
5143 // We created GOT entries in the .got.tlsdesc portion of
5144 // the .got.plt section, but the offset stored in the
5145 // symbol is the offset within .got.tlsdesc.
5146 got_offset = (target->got_size()
5147 + target->got_plt_section()->data_size());
5148 }
5149 if (gsym != NULL)
5150 {
5151 gold_assert(gsym->has_got_offset(got_type));
5152 got_offset += gsym->got_offset(got_type) - target->got_size();
5153 }
5154 else
5155 {
5156 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5157 gold_assert(object->local_has_got_offset(r_sym, got_type));
5158 got_offset += (object->local_got_offset(r_sym, got_type)
5159 - target->got_size());
5160 }
5161 if (optimized_type == tls::TLSOPT_TO_IE)
5162 {
5163 value = target->got_plt_section()->address() + got_offset;
5164 this->tls_desc_gd_to_ie(relinfo, relnum,
5165 rela, r_type, value, view, address,
5166 view_size);
5167 break;
5168 }
5169 else if (optimized_type == tls::TLSOPT_NONE)
5170 {
5171 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5172 {
5173 // Relocate the field with the offset of the pair of GOT
5174 // entries.
5175 value = target->got_plt_section()->address() + got_offset;
5176 Relocate_functions<size, false>::pcrela32(view, value, addend,
5177 address);
5178 }
5179 break;
5180 }
5181 }
5182 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5183 _("unsupported reloc %u"), r_type);
5184 break;
5185
5186 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
5187 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5188 {
5189 // See above comment for R_X86_64_TLSGD.
5190 optimized_type = tls::TLSOPT_NONE;
5191 }
5192 if (optimized_type == tls::TLSOPT_TO_LE)
5193 {
5194 if (tls_segment == NULL)
5195 {
5196 gold_assert(parameters->errors()->error_count() > 0
5197 || issue_undefined_symbol_error(gsym));
5198 return;
5199 }
5200 this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
5201 value, view, view_size);
5202 break;
5203 }
5204 else if (optimized_type == tls::TLSOPT_NONE)
5205 {
5206 // Relocate the field with the offset of the GOT entry for
5207 // the module index.
5208 unsigned int got_offset;
5209 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
5210 - target->got_size());
5211 value = target->got_plt_section()->address() + got_offset;
5212 Relocate_functions<size, false>::pcrela32(view, value, addend,
5213 address);
5214 break;
5215 }
5216 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5217 _("unsupported reloc %u"), r_type);
5218 break;
5219
5220 case elfcpp::R_X86_64_DTPOFF32:
5221 // This relocation type is used in debugging information.
5222 // In that case we need to not optimize the value. If the
5223 // section is not executable, then we assume we should not
5224 // optimize this reloc. See comments above for R_X86_64_TLSGD,
5225 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
5226 // R_X86_64_TLSLD.
5227 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
5228 {
5229 if (tls_segment == NULL)
5230 {
5231 gold_assert(parameters->errors()->error_count() > 0
5232 || issue_undefined_symbol_error(gsym));
5233 return;
5234 }
5235 value -= tls_segment->memsz();
5236 }
5237 Relocate_functions<size, false>::rela32(view, value, addend);
5238 break;
5239
5240 case elfcpp::R_X86_64_DTPOFF64:
5241 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
5242 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
5243 {
5244 if (tls_segment == NULL)
5245 {
5246 gold_assert(parameters->errors()->error_count() > 0
5247 || issue_undefined_symbol_error(gsym));
5248 return;
5249 }
5250 value -= tls_segment->memsz();
5251 }
5252 Relocate_functions<size, false>::rela64(view, value, addend);
5253 break;
5254
5255 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
5256 if (gsym != NULL
5257 && gsym->is_undefined()
5258 && parameters->options().output_is_executable())
5259 {
5260 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
5261 NULL, rela,
5262 r_type, value, view,
5263 view_size);
5264 break;
5265 }
5266 else if (optimized_type == tls::TLSOPT_TO_LE)
5267 {
5268 if (tls_segment == NULL)
5269 {
5270 gold_assert(parameters->errors()->error_count() > 0
5271 || issue_undefined_symbol_error(gsym));
5272 return;
5273 }
5274 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
5275 tls_segment, rela,
5276 r_type, value, view,
5277 view_size);
5278 break;
5279 }
5280 else if (optimized_type == tls::TLSOPT_NONE)
5281 {
5282 // Relocate the field with the offset of the GOT entry for
5283 // the tp-relative offset of the symbol.
5284 unsigned int got_offset;
5285 if (gsym != NULL)
5286 {
5287 gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
5288 got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
5289 - target->got_size());
5290 }
5291 else
5292 {
5293 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5294 gold_assert(object->local_has_got_offset(r_sym,
5295 GOT_TYPE_TLS_OFFSET));
5296 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
5297 - target->got_size());
5298 }
5299 value = target->got_plt_section()->address() + got_offset;
5300 Relocate_functions<size, false>::pcrela32(view, value, addend,
5301 address);
5302 break;
5303 }
5304 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5305 _("unsupported reloc type %u"),
5306 r_type);
5307 break;
5308
5309 case elfcpp::R_X86_64_TPOFF32: // Local-exec
5310 if (tls_segment == NULL)
5311 {
5312 gold_assert(parameters->errors()->error_count() > 0
5313 || issue_undefined_symbol_error(gsym));
5314 return;
5315 }
5316 value -= tls_segment->memsz();
5317 Relocate_functions<size, false>::rela32(view, value, addend);
5318 break;
5319 }
5320 }
5321
5322 // Do a relocation in which we convert a TLS General-Dynamic to an
5323 // Initial-Exec.
5324
5325 template<int size>
5326 inline void
5327 Target_x86_64<size>::Relocate::tls_gd_to_ie(
5328 const Relocate_info<size, false>* relinfo,
5329 size_t relnum,
5330 const elfcpp::Rela<size, false>& rela,
5331 unsigned int,
5332 typename elfcpp::Elf_types<size>::Elf_Addr value,
5333 unsigned char* view,
5334 typename elfcpp::Elf_types<size>::Elf_Addr address,
5335 section_size_type view_size)
5336 {
5337 // For SIZE == 64:
5338 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5339 // .word 0x6666; rex64; call __tls_get_addr@PLT
5340 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5341 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5342 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5343 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5344 // For SIZE == 32:
5345 // leaq foo@tlsgd(%rip),%rdi;
5346 // .word 0x6666; rex64; call __tls_get_addr@PLT
5347 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5348 // leaq foo@tlsgd(%rip),%rdi;
5349 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5350 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5351
5352 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
5353 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5354 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
5355 || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
5356
5357 if (size == 64)
5358 {
5359 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5360 -4);
5361 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5362 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
5363 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5364 16);
5365 }
5366 else
5367 {
5368 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5369 -3);
5370 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5371 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
5372 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5373 15);
5374 }
5375
5376 const elfcpp::Elf_Xword addend = rela.get_r_addend();
5377 Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
5378 address);
5379
5380 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5381 // We can skip it.
5382 this->skip_call_tls_get_addr_ = true;
5383 }
5384
5385 // Do a relocation in which we convert a TLS General-Dynamic to a
5386 // Local-Exec.
5387
5388 template<int size>
5389 inline void
5390 Target_x86_64<size>::Relocate::tls_gd_to_le(
5391 const Relocate_info<size, false>* relinfo,
5392 size_t relnum,
5393 Output_segment* tls_segment,
5394 const elfcpp::Rela<size, false>& rela,
5395 unsigned int,
5396 typename elfcpp::Elf_types<size>::Elf_Addr value,
5397 unsigned char* view,
5398 section_size_type view_size)
5399 {
5400 // For SIZE == 64:
5401 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5402 // .word 0x6666; rex64; call __tls_get_addr@PLT
5403 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5404 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5405 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5406 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5407 // For SIZE == 32:
5408 // leaq foo@tlsgd(%rip),%rdi;
5409 // .word 0x6666; rex64; call __tls_get_addr@PLT
5410 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5411 // leaq foo@tlsgd(%rip),%rdi;
5412 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5413 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5414
5415 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
5416 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5417 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
5418 || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
5419
5420 if (size == 64)
5421 {
5422 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5423 -4);
5424 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5425 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
5426 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5427 16);
5428 }
5429 else
5430 {
5431 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5432 -3);
5433 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5434 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
5435
5436 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5437 15);
5438 }
5439
5440 value -= tls_segment->memsz();
5441 Relocate_functions<size, false>::rela32(view + 8, value, 0);
5442
5443 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5444 // We can skip it.
5445 this->skip_call_tls_get_addr_ = true;
5446 }
5447
5448 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
5449
5450 template<int size>
5451 inline void
5452 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
5453 const Relocate_info<size, false>* relinfo,
5454 size_t relnum,
5455 const elfcpp::Rela<size, false>& rela,
5456 unsigned int r_type,
5457 typename elfcpp::Elf_types<size>::Elf_Addr value,
5458 unsigned char* view,
5459 typename elfcpp::Elf_types<size>::Elf_Addr address,
5460 section_size_type view_size)
5461 {
5462 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5463 {
5464 // leaq foo@tlsdesc(%rip), %rax
5465 // ==> movq foo@gottpoff(%rip), %rax
5466 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5467 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5468 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5469 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
5470 view[-2] = 0x8b;
5471 const elfcpp::Elf_Xword addend = rela.get_r_addend();
5472 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
5473 }
5474 else
5475 {
5476 // call *foo@tlscall(%rax)
5477 // ==> nop; nop
5478 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
5479 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
5480 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5481 view[0] == 0xff && view[1] == 0x10);
5482 view[0] = 0x66;
5483 view[1] = 0x90;
5484 }
5485 }
5486
5487 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
5488
5489 template<int size>
5490 inline void
5491 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
5492 const Relocate_info<size, false>* relinfo,
5493 size_t relnum,
5494 Output_segment* tls_segment,
5495 const elfcpp::Rela<size, false>& rela,
5496 unsigned int r_type,
5497 typename elfcpp::Elf_types<size>::Elf_Addr value,
5498 unsigned char* view,
5499 section_size_type view_size)
5500 {
5501 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5502 {
5503 // leaq foo@tlsdesc(%rip), %rax
5504 // ==> movq foo@tpoff, %rax
5505 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5506 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5507 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5508 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
5509 view[-2] = 0xc7;
5510 view[-1] = 0xc0;
5511 value -= tls_segment->memsz();
5512 Relocate_functions<size, false>::rela32(view, value, 0);
5513 }
5514 else
5515 {
5516 // call *foo@tlscall(%rax)
5517 // ==> nop; nop
5518 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
5519 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
5520 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5521 view[0] == 0xff && view[1] == 0x10);
5522 view[0] = 0x66;
5523 view[1] = 0x90;
5524 }
5525 }
5526
5527 template<int size>
5528 inline void
5529 Target_x86_64<size>::Relocate::tls_ld_to_le(
5530 const Relocate_info<size, false>* relinfo,
5531 size_t relnum,
5532 Output_segment*,
5533 const elfcpp::Rela<size, false>& rela,
5534 unsigned int,
5535 typename elfcpp::Elf_types<size>::Elf_Addr,
5536 unsigned char* view,
5537 section_size_type view_size)
5538 {
5539 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
5540 // For SIZE == 64:
5541 // ... leq foo@dtpoff(%rax),%reg
5542 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5543 // For SIZE == 32:
5544 // ... leq foo@dtpoff(%rax),%reg
5545 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5546 // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
5547 // For SIZE == 64:
5548 // ... leq foo@dtpoff(%rax),%reg
5549 // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5550 // For SIZE == 32:
5551 // ... leq foo@dtpoff(%rax),%reg
5552 // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5553
5554 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5555 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
5556
5557 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5558 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
5559
5560 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5561 view[4] == 0xe8 || view[4] == 0xff);
5562
5563 if (view[4] == 0xe8)
5564 {
5565 if (size == 64)
5566 memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
5567 else
5568 memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
5569 }
5570 else
5571 {
5572 if (size == 64)
5573 memcpy(view - 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
5574 13);
5575 else
5576 memcpy(view - 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
5577 13);
5578 }
5579
5580 // The next reloc should be a PLT32 reloc against __tls_get_addr.
5581 // We can skip it.
5582 this->skip_call_tls_get_addr_ = true;
5583 }
5584
5585 // Do a relocation in which we convert a TLS Initial-Exec to a
5586 // Local-Exec.
5587
5588 template<int size>
5589 inline void
5590 Target_x86_64<size>::Relocate::tls_ie_to_le(
5591 const Relocate_info<size, false>* relinfo,
5592 size_t relnum,
5593 Output_segment* tls_segment,
5594 const elfcpp::Rela<size, false>& rela,
5595 unsigned int,
5596 typename elfcpp::Elf_types<size>::Elf_Addr value,
5597 unsigned char* view,
5598 section_size_type view_size)
5599 {
5600 // We need to examine the opcodes to figure out which instruction we
5601 // are looking at.
5602
5603 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
5604 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
5605
5606 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5607 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5608
5609 unsigned char op1 = view[-3];
5610 unsigned char op2 = view[-2];
5611 unsigned char op3 = view[-1];
5612 unsigned char reg = op3 >> 3;
5613
5614 if (op2 == 0x8b)
5615 {
5616 // movq
5617 if (op1 == 0x4c)
5618 view[-3] = 0x49;
5619 else if (size == 32 && op1 == 0x44)
5620 view[-3] = 0x41;
5621 view[-2] = 0xc7;
5622 view[-1] = 0xc0 | reg;
5623 }
5624 else if (reg == 4)
5625 {
5626 // Special handling for %rsp.
5627 if (op1 == 0x4c)
5628 view[-3] = 0x49;
5629 else if (size == 32 && op1 == 0x44)
5630 view[-3] = 0x41;
5631 view[-2] = 0x81;
5632 view[-1] = 0xc0 | reg;
5633 }
5634 else
5635 {
5636 // addq
5637 if (op1 == 0x4c)
5638 view[-3] = 0x4d;
5639 else if (size == 32 && op1 == 0x44)
5640 view[-3] = 0x45;
5641 view[-2] = 0x8d;
5642 view[-1] = 0x80 | reg | (reg << 3);
5643 }
5644
5645 if (tls_segment != NULL)
5646 value -= tls_segment->memsz();
5647 Relocate_functions<size, false>::rela32(view, value, 0);
5648 }
5649
5650 // Relocate section data.
5651
5652 template<int size>
5653 void
5654 Target_x86_64<size>::relocate_section(
5655 const Relocate_info<size, false>* relinfo,
5656 unsigned int sh_type,
5657 const unsigned char* prelocs,
5658 size_t reloc_count,
5659 Output_section* output_section,
5660 bool needs_special_offset_handling,
5661 unsigned char* view,
5662 typename elfcpp::Elf_types<size>::Elf_Addr address,
5663 section_size_type view_size,
5664 const Reloc_symbol_changes* reloc_symbol_changes)
5665 {
5666 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5667 Classify_reloc;
5668
5669 gold_assert(sh_type == elfcpp::SHT_RELA);
5670
5671 gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
5672 gold::Default_comdat_behavior, Classify_reloc>(
5673 relinfo,
5674 this,
5675 prelocs,
5676 reloc_count,
5677 output_section,
5678 needs_special_offset_handling,
5679 view,
5680 address,
5681 view_size,
5682 reloc_symbol_changes);
5683 }
5684
5685 // Apply an incremental relocation. Incremental relocations always refer
5686 // to global symbols.
5687
5688 template<int size>
5689 void
5690 Target_x86_64<size>::apply_relocation(
5691 const Relocate_info<size, false>* relinfo,
5692 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
5693 unsigned int r_type,
5694 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
5695 const Symbol* gsym,
5696 unsigned char* view,
5697 typename elfcpp::Elf_types<size>::Elf_Addr address,
5698 section_size_type view_size)
5699 {
5700 gold::apply_relocation<size, false, Target_x86_64<size>,
5701 typename Target_x86_64<size>::Relocate>(
5702 relinfo,
5703 this,
5704 r_offset,
5705 r_type,
5706 r_addend,
5707 gsym,
5708 view,
5709 address,
5710 view_size);
5711 }
5712
5713 // Scan the relocs during a relocatable link.
5714
5715 template<int size>
5716 void
5717 Target_x86_64<size>::scan_relocatable_relocs(
5718 Symbol_table* symtab,
5719 Layout* layout,
5720 Sized_relobj_file<size, false>* object,
5721 unsigned int data_shndx,
5722 unsigned int sh_type,
5723 const unsigned char* prelocs,
5724 size_t reloc_count,
5725 Output_section* output_section,
5726 bool needs_special_offset_handling,
5727 size_t local_symbol_count,
5728 const unsigned char* plocal_symbols,
5729 Relocatable_relocs* rr)
5730 {
5731 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5732 Classify_reloc;
5733 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
5734 Scan_relocatable_relocs;
5735
5736 gold_assert(sh_type == elfcpp::SHT_RELA);
5737
5738 gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
5739 symtab,
5740 layout,
5741 object,
5742 data_shndx,
5743 prelocs,
5744 reloc_count,
5745 output_section,
5746 needs_special_offset_handling,
5747 local_symbol_count,
5748 plocal_symbols,
5749 rr);
5750 }
5751
5752 // Scan the relocs for --emit-relocs.
5753
5754 template<int size>
5755 void
5756 Target_x86_64<size>::emit_relocs_scan(
5757 Symbol_table* symtab,
5758 Layout* layout,
5759 Sized_relobj_file<size, false>* object,
5760 unsigned int data_shndx,
5761 unsigned int sh_type,
5762 const unsigned char* prelocs,
5763 size_t reloc_count,
5764 Output_section* output_section,
5765 bool needs_special_offset_handling,
5766 size_t local_symbol_count,
5767 const unsigned char* plocal_syms,
5768 Relocatable_relocs* rr)
5769 {
5770 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5771 Classify_reloc;
5772 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
5773 Emit_relocs_strategy;
5774
5775 gold_assert(sh_type == elfcpp::SHT_RELA);
5776
5777 gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
5778 symtab,
5779 layout,
5780 object,
5781 data_shndx,
5782 prelocs,
5783 reloc_count,
5784 output_section,
5785 needs_special_offset_handling,
5786 local_symbol_count,
5787 plocal_syms,
5788 rr);
5789 }
5790
5791 // Relocate a section during a relocatable link.
5792
5793 template<int size>
5794 void
5795 Target_x86_64<size>::relocate_relocs(
5796 const Relocate_info<size, false>* relinfo,
5797 unsigned int sh_type,
5798 const unsigned char* prelocs,
5799 size_t reloc_count,
5800 Output_section* output_section,
5801 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
5802 unsigned char* view,
5803 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
5804 section_size_type view_size,
5805 unsigned char* reloc_view,
5806 section_size_type reloc_view_size)
5807 {
5808 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5809 Classify_reloc;
5810
5811 gold_assert(sh_type == elfcpp::SHT_RELA);
5812
5813 gold::relocate_relocs<size, false, Classify_reloc>(
5814 relinfo,
5815 prelocs,
5816 reloc_count,
5817 output_section,
5818 offset_in_output_section,
5819 view,
5820 view_address,
5821 view_size,
5822 reloc_view,
5823 reloc_view_size);
5824 }
5825
5826 // Return the value to use for a dynamic which requires special
5827 // treatment. This is how we support equality comparisons of function
5828 // pointers across shared library boundaries, as described in the
5829 // processor specific ABI supplement.
5830
5831 template<int size>
5832 uint64_t
5833 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
5834 {
5835 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
5836 return this->plt_address_for_global(gsym);
5837 }
5838
5839 // Return a string used to fill a code section with nops to take up
5840 // the specified length.
5841
5842 template<int size>
5843 std::string
5844 Target_x86_64<size>::do_code_fill(section_size_type length) const
5845 {
5846 if (length >= 16)
5847 {
5848 // Build a jmpq instruction to skip over the bytes.
5849 unsigned char jmp[5];
5850 jmp[0] = 0xe9;
5851 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
5852 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
5853 + std::string(length - 5, static_cast<char>(0x90)));
5854 }
5855
5856 // Nop sequences of various lengths.
5857 const char nop1[1] = { '\x90' }; // nop
5858 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
5859 const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5860 const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
5861 '\x00'};
5862 const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
5863 '\x00', '\x00' };
5864 const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
5865 '\x44', '\x00', '\x00' };
5866 const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
5867 '\x00', '\x00', '\x00',
5868 '\x00' };
5869 const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
5870 '\x00', '\x00', '\x00',
5871 '\x00', '\x00' };
5872 const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
5873 '\x84', '\x00', '\x00',
5874 '\x00', '\x00', '\x00' };
5875 const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5876 '\x1f', '\x84', '\x00',
5877 '\x00', '\x00', '\x00',
5878 '\x00' };
5879 const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
5880 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5881 '\x00', '\x00', '\x00',
5882 '\x00', '\x00' };
5883 const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
5884 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5885 '\x84', '\x00', '\x00',
5886 '\x00', '\x00', '\x00' };
5887 const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5888 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5889 '\x1f', '\x84', '\x00',
5890 '\x00', '\x00', '\x00',
5891 '\x00' };
5892 const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5893 '\x66', '\x66', '\x2e', // data16
5894 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5895 '\x00', '\x00', '\x00',
5896 '\x00', '\x00' };
5897 const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5898 '\x66', '\x66', '\x66', // data16; data16
5899 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5900 '\x84', '\x00', '\x00',
5901 '\x00', '\x00', '\x00' };
5902
5903 const char* nops[16] = {
5904 NULL,
5905 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
5906 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
5907 };
5908
5909 return std::string(nops[length], length);
5910 }
5911
5912 // Return the addend to use for a target specific relocation. The
5913 // only target specific relocation is R_X86_64_TLSDESC for a local
5914 // symbol. We want to set the addend is the offset of the local
5915 // symbol in the TLS segment.
5916
5917 template<int size>
5918 uint64_t
5919 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
5920 uint64_t) const
5921 {
5922 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
5923 uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
5924 gold_assert(intarg < this->tlsdesc_reloc_info_.size());
5925 const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
5926 const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
5927 gold_assert(psymval->is_tls_symbol());
5928 // The value of a TLS symbol is the offset in the TLS segment.
5929 return psymval->value(ti.object, 0);
5930 }
5931
5932 // Return the value to use for the base of a DW_EH_PE_datarel offset
5933 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
5934 // assembler can not write out the difference between two labels in
5935 // different sections, so instead of using a pc-relative value they
5936 // use an offset from the GOT.
5937
5938 template<int size>
5939 uint64_t
5940 Target_x86_64<size>::do_ehframe_datarel_base() const
5941 {
5942 gold_assert(this->global_offset_table_ != NULL);
5943 Symbol* sym = this->global_offset_table_;
5944 Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
5945 return ssym->value();
5946 }
5947
5948 // FNOFFSET in section SHNDX in OBJECT is the start of a function
5949 // compiled with -fsplit-stack. The function calls non-split-stack
5950 // code. We have to change the function so that it always ensures
5951 // that it has enough stack space to run some random function.
5952
5953 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
5954 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
5955 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
5956
5957 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
5958 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
5959 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
5960
5961 template<int size>
5962 void
5963 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
5964 section_offset_type fnoffset,
5965 section_size_type fnsize,
5966 const unsigned char*,
5967 size_t,
5968 unsigned char* view,
5969 section_size_type view_size,
5970 std::string* from,
5971 std::string* to) const
5972 {
5973 const char* const cmp_insn = reinterpret_cast<const char*>
5974 (size == 32 ? cmp_insn_32 : cmp_insn_64);
5975 const char* const lea_r10_insn = reinterpret_cast<const char*>
5976 (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
5977 const char* const lea_r11_insn = reinterpret_cast<const char*>
5978 (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
5979
5980 const size_t cmp_insn_len =
5981 (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
5982 const size_t lea_r10_insn_len =
5983 (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
5984 const size_t lea_r11_insn_len =
5985 (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
5986 const size_t nop_len = (size == 32 ? 7 : 8);
5987
5988 // The function starts with a comparison of the stack pointer and a
5989 // field in the TCB. This is followed by a jump.
5990
5991 // cmp %fs:NN,%rsp
5992 if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
5993 && fnsize > nop_len + 1)
5994 {
5995 // We will call __morestack if the carry flag is set after this
5996 // comparison. We turn the comparison into an stc instruction
5997 // and some nops.
5998 view[fnoffset] = '\xf9';
5999 this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
6000 }
6001 // lea NN(%rsp),%r10
6002 // lea NN(%rsp),%r11
6003 else if ((this->match_view(view, view_size, fnoffset,
6004 lea_r10_insn, lea_r10_insn_len)
6005 || this->match_view(view, view_size, fnoffset,
6006 lea_r11_insn, lea_r11_insn_len))
6007 && fnsize > 8)
6008 {
6009 // This is loading an offset from the stack pointer for a
6010 // comparison. The offset is negative, so we decrease the
6011 // offset by the amount of space we need for the stack. This
6012 // means we will avoid calling __morestack if there happens to
6013 // be plenty of space on the stack already.
6014 unsigned char* pval = view + fnoffset + 4;
6015 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
6016 val -= parameters->options().split_stack_adjust_size();
6017 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
6018 }
6019 else
6020 {
6021 if (!object->has_no_split_stack())
6022 object->error(_("failed to match split-stack sequence at "
6023 "section %u offset %0zx"),
6024 shndx, static_cast<size_t>(fnoffset));
6025 return;
6026 }
6027
6028 // We have to change the function so that it calls
6029 // __morestack_non_split instead of __morestack. The former will
6030 // allocate additional stack space.
6031 *from = "__morestack";
6032 *to = "__morestack_non_split";
6033 }
6034
6035 // The selector for x86_64 object files. Note this is never instantiated
6036 // directly. It's only used in Target_selector_x86_64_nacl, below.
6037
6038 template<int size>
6039 class Target_selector_x86_64 : public Target_selector_freebsd
6040 {
6041 public:
6042 Target_selector_x86_64()
6043 : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
6044 (size == 64
6045 ? "elf64-x86-64" : "elf32-x86-64"),
6046 (size == 64
6047 ? "elf64-x86-64-freebsd"
6048 : "elf32-x86-64-freebsd"),
6049 (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
6050 { }
6051
6052 Target*
6053 do_instantiate_target()
6054 { return new Target_x86_64<size>(); }
6055
6056 };
6057
6058 // NaCl variant. It uses different PLT contents.
6059
6060 template<int size>
6061 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
6062 {
6063 public:
6064 Output_data_plt_x86_64_nacl(Layout* layout,
6065 Output_data_got<64, false>* got,
6066 Output_data_got_plt_x86_64* got_plt,
6067 Output_data_space* got_irelative)
6068 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
6069 got, got_plt, got_irelative)
6070 { }
6071
6072 Output_data_plt_x86_64_nacl(Layout* layout,
6073 Output_data_got<64, false>* got,
6074 Output_data_got_plt_x86_64* got_plt,
6075 Output_data_space* got_irelative,
6076 unsigned int plt_count)
6077 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
6078 got, got_plt, got_irelative,
6079 plt_count)
6080 { }
6081
6082 protected:
6083 virtual unsigned int
6084 do_get_plt_entry_size() const
6085 { return plt_entry_size; }
6086
6087 virtual void
6088 do_add_eh_frame(Layout* layout)
6089 {
6090 layout->add_eh_frame_for_plt(this,
6091 this->plt_eh_frame_cie,
6092 this->plt_eh_frame_cie_size,
6093 plt_eh_frame_fde,
6094 plt_eh_frame_fde_size);
6095 }
6096
6097 virtual void
6098 do_fill_first_plt_entry(unsigned char* pov,
6099 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
6100 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
6101
6102 virtual unsigned int
6103 do_fill_plt_entry(unsigned char* pov,
6104 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6105 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6106 unsigned int got_offset,
6107 unsigned int plt_offset,
6108 unsigned int plt_index);
6109
6110 virtual void
6111 do_fill_tlsdesc_entry(unsigned char* pov,
6112 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6113 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6114 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
6115 unsigned int tlsdesc_got_offset,
6116 unsigned int plt_offset);
6117
6118 private:
6119 // The size of an entry in the PLT.
6120 static const int plt_entry_size = 64;
6121
6122 // The first entry in the PLT.
6123 static const unsigned char first_plt_entry[plt_entry_size];
6124
6125 // Other entries in the PLT for an executable.
6126 static const unsigned char plt_entry[plt_entry_size];
6127
6128 // The reserved TLSDESC entry in the PLT for an executable.
6129 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
6130
6131 // The .eh_frame unwind information for the PLT.
6132 static const int plt_eh_frame_fde_size = 32;
6133 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
6134 };
6135
6136 template<int size>
6137 class Target_x86_64_nacl : public Target_x86_64<size>
6138 {
6139 public:
6140 Target_x86_64_nacl()
6141 : Target_x86_64<size>(&x86_64_nacl_info)
6142 { }
6143
6144 virtual Output_data_plt_x86_64<size>*
6145 do_make_data_plt(Layout* layout,
6146 Output_data_got<64, false>* got,
6147 Output_data_got_plt_x86_64* got_plt,
6148 Output_data_space* got_irelative)
6149 {
6150 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
6151 got_irelative);
6152 }
6153
6154 virtual Output_data_plt_x86_64<size>*
6155 do_make_data_plt(Layout* layout,
6156 Output_data_got<64, false>* got,
6157 Output_data_got_plt_x86_64* got_plt,
6158 Output_data_space* got_irelative,
6159 unsigned int plt_count)
6160 {
6161 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
6162 got_irelative,
6163 plt_count);
6164 }
6165
6166 virtual std::string
6167 do_code_fill(section_size_type length) const;
6168
6169 private:
6170 static const Target::Target_info x86_64_nacl_info;
6171 };
6172
6173 template<>
6174 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
6175 {
6176 64, // size
6177 false, // is_big_endian
6178 elfcpp::EM_X86_64, // machine_code
6179 false, // has_make_symbol
6180 false, // has_resolve
6181 true, // has_code_fill
6182 true, // is_default_stack_executable
6183 true, // can_icf_inline_merge_sections
6184 '\0', // wrap_char
6185 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
6186 0x20000, // default_text_segment_address
6187 0x10000, // abi_pagesize (overridable by -z max-page-size)
6188 0x10000, // common_pagesize (overridable by -z common-page-size)
6189 true, // isolate_execinstr
6190 0x10000000, // rosegment_gap
6191 elfcpp::SHN_UNDEF, // small_common_shndx
6192 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
6193 0, // small_common_section_flags
6194 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
6195 NULL, // attributes_section
6196 NULL, // attributes_vendor
6197 "_start", // entry_symbol_name
6198 32, // hash_entry_size
6199 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
6200 };
6201
6202 template<>
6203 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
6204 {
6205 32, // size
6206 false, // is_big_endian
6207 elfcpp::EM_X86_64, // machine_code
6208 false, // has_make_symbol
6209 false, // has_resolve
6210 true, // has_code_fill
6211 true, // is_default_stack_executable
6212 true, // can_icf_inline_merge_sections
6213 '\0', // wrap_char
6214 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
6215 0x20000, // default_text_segment_address
6216 0x10000, // abi_pagesize (overridable by -z max-page-size)
6217 0x10000, // common_pagesize (overridable by -z common-page-size)
6218 true, // isolate_execinstr
6219 0x10000000, // rosegment_gap
6220 elfcpp::SHN_UNDEF, // small_common_shndx
6221 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
6222 0, // small_common_section_flags
6223 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
6224 NULL, // attributes_section
6225 NULL, // attributes_vendor
6226 "_start", // entry_symbol_name
6227 32, // hash_entry_size
6228 elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
6229 };
6230
6231 #define NACLMASK 0xe0 // 32-byte alignment mask.
6232
6233 // The first entry in the PLT.
6234
6235 template<int size>
6236 const unsigned char
6237 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
6238 {
6239 0xff, 0x35, // pushq contents of memory address
6240 0, 0, 0, 0, // replaced with address of .got + 8
6241 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
6242 0, 0, 0, 0, // replaced with address of .got + 16
6243 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
6244 0x4d, 0x01, 0xfb, // add %r15, %r11
6245 0x41, 0xff, 0xe3, // jmpq *%r11
6246
6247 // 9-byte nop sequence to pad out to the next 32-byte boundary.
6248 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
6249
6250 // 32 bytes of nop to pad out to the standard size
6251 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6252 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6253 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6254 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6255 0x66, // excess data32 prefix
6256 0x90 // nop
6257 };
6258
6259 template<int size>
6260 void
6261 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
6262 unsigned char* pov,
6263 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6264 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
6265 {
6266 memcpy(pov, first_plt_entry, plt_entry_size);
6267 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
6268 (got_address + 8
6269 - (plt_address + 2 + 4)));
6270 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
6271 (got_address + 16
6272 - (plt_address + 9 + 4)));
6273 }
6274
6275 // Subsequent entries in the PLT.
6276
6277 template<int size>
6278 const unsigned char
6279 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
6280 {
6281 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
6282 0, 0, 0, 0, // replaced with address of symbol in .got
6283 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
6284 0x4d, 0x01, 0xfb, // add %r15, %r11
6285 0x41, 0xff, 0xe3, // jmpq *%r11
6286
6287 // 15-byte nop sequence to pad out to the next 32-byte boundary.
6288 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6289 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6290
6291 // Lazy GOT entries point here (32-byte aligned).
6292 0x68, // pushq immediate
6293 0, 0, 0, 0, // replaced with index into relocation table
6294 0xe9, // jmp relative
6295 0, 0, 0, 0, // replaced with offset to start of .plt0
6296
6297 // 22 bytes of nop to pad out to the standard size.
6298 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6299 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6300 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
6301 };
6302
6303 template<int size>
6304 unsigned int
6305 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
6306 unsigned char* pov,
6307 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6308 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6309 unsigned int got_offset,
6310 unsigned int plt_offset,
6311 unsigned int plt_index)
6312 {
6313 memcpy(pov, plt_entry, plt_entry_size);
6314 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
6315 (got_address + got_offset
6316 - (plt_address + plt_offset
6317 + 3 + 4)));
6318
6319 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
6320 elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
6321 - (plt_offset + 38 + 4));
6322
6323 return 32;
6324 }
6325
6326 // The reserved TLSDESC entry in the PLT.
6327
6328 template<int size>
6329 const unsigned char
6330 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
6331 {
6332 0xff, 0x35, // pushq x(%rip)
6333 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
6334 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
6335 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
6336 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
6337 0x4d, 0x01, 0xfb, // add %r15, %r11
6338 0x41, 0xff, 0xe3, // jmpq *%r11
6339
6340 // 41 bytes of nop to pad out to the standard size.
6341 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6342 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6343 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
6344 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6345 0x66, 0x66, // excess data32 prefixes
6346 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6347 };
6348
6349 template<int size>
6350 void
6351 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
6352 unsigned char* pov,
6353 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6354 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6355 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
6356 unsigned int tlsdesc_got_offset,
6357 unsigned int plt_offset)
6358 {
6359 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
6360 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
6361 (got_address + 8
6362 - (plt_address + plt_offset
6363 + 2 + 4)));
6364 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
6365 (got_base
6366 + tlsdesc_got_offset
6367 - (plt_address + plt_offset
6368 + 9 + 4)));
6369 }
6370
6371 // The .eh_frame unwind information for the PLT.
6372
6373 template<int size>
6374 const unsigned char
6375 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
6376 {
6377 0, 0, 0, 0, // Replaced with offset to .plt.
6378 0, 0, 0, 0, // Replaced with size of .plt.
6379 0, // Augmentation size.
6380 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
6381 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
6382 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
6383 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
6384 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
6385 13, // Block length.
6386 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
6387 elfcpp::DW_OP_breg16, 0, // Push %rip.
6388 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
6389 elfcpp::DW_OP_and, // & (%rip & 0x3f).
6390 elfcpp::DW_OP_const1u, 37, // Push 0x25.
6391 elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25)
6392 elfcpp::DW_OP_lit3, // Push 3.
6393 elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3)
6394 elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
6395 elfcpp::DW_CFA_nop, // Align to 32 bytes.
6396 elfcpp::DW_CFA_nop
6397 };
6398
6399 // Return a string used to fill a code section with nops.
6400 // For NaCl, long NOPs are only valid if they do not cross
6401 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
6402 template<int size>
6403 std::string
6404 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
6405 {
6406 return std::string(length, static_cast<char>(0x90));
6407 }
6408
6409 // The selector for x86_64-nacl object files.
6410
6411 template<int size>
6412 class Target_selector_x86_64_nacl
6413 : public Target_selector_nacl<Target_selector_x86_64<size>,
6414 Target_x86_64_nacl<size> >
6415 {
6416 public:
6417 Target_selector_x86_64_nacl()
6418 : Target_selector_nacl<Target_selector_x86_64<size>,
6419 Target_x86_64_nacl<size> >("x86-64",
6420 size == 64
6421 ? "elf64-x86-64-nacl"
6422 : "elf32-x86-64-nacl",
6423 size == 64
6424 ? "elf_x86_64_nacl"
6425 : "elf32_x86_64_nacl")
6426 { }
6427 };
6428
6429 Target_selector_x86_64_nacl<64> target_selector_x86_64;
6430 Target_selector_x86_64_nacl<32> target_selector_x32;
6431
6432 } // End anonymous namespace.