aboutsummaryrefslogtreecommitdiff
path: root/gold/i386.cc
blob: 468cb90efe7c095ed291c06340ee3efacfc71529 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
// i386.cc -- i386 target support for gold.

#include "gold.h"
#include "elfcpp.h"
#include "reloc.h"
#include "i386.h"
#include "object.h"
#include "layout.h"
#include "output.h"
#include "target.h"
#include "target-reloc.h"
#include "target-select.h"

namespace
{

using namespace gold;

// The i386 target class.

class Target_i386 : public Sized_target<32, false>
{
 public:
  Target_i386()
    : Sized_target<32, false>(&i386_info)
  { }

  // Scan the relocations to look for symbol adjustments.
  void
  scan_relocs(const General_options& options,
	      Symbol_table* symtab,
	      Sized_object<32, false>* object,
	      unsigned int sh_type,
	      const unsigned char* prelocs,
	      size_t reloc_count,
	      size_t local_symbol_count,
	      const unsigned char* plocal_symbols,
	      Symbol** global_symbols);

  // Relocate a section.
  void
  relocate_section(const Relocate_info<32, false>*,
		   unsigned int sh_type,
		   const unsigned char* prelocs,
		   size_t reloc_count,
		   unsigned char* view,
		   elfcpp::Elf_types<32>::Elf_Addr view_address,
		   off_t view_size);

 private:
  // The class which scans relocations.
  struct Scan
  {
    inline void
    local(const General_options& options, Sized_object<32, false>* object,
	  const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
	  const elfcpp::Sym<32, false>& lsym);

    inline void
    global(const General_options& options, Sized_object<32, false>* object,
	   const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
	   Symbol* gsym);
  };

  // The class which implements relocation.
  class Relocate
  {
   public:
    // Do a relocation.
    static inline void
    relocate(const Relocate_info<32, false>*, size_t relnum,
	     const elfcpp::Rel<32, false>&,
	     unsigned int r_type, Sized_symbol<32>*,
	     elfcpp::Elf_types<32>::Elf_Addr,
	     unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
	     off_t);

   private:
    // Do a TLS relocation.
    static inline void
    relocate_tls(const Relocate_info<32, false>*, size_t relnum,
		 const elfcpp::Rel<32, false>&,
		 unsigned int r_type, Sized_symbol<32>*,
		 elfcpp::Elf_types<32>::Elf_Addr,
		 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);

    // Do a TLS Initial-Exec to Local-Exec transition.
    static inline void
    tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
		 Output_segment* tls_segment,
		 const elfcpp::Rel<32, false>&, unsigned int r_type,
		 elfcpp::Elf_types<32>::Elf_Addr value,
		 unsigned char* view,
		 off_t view_size);

    // Check the range for a TLS relocation.
    static inline void
    check_range(const Relocate_info<32, false>*, size_t relnum,
		const elfcpp::Rel<32, false>&, off_t, off_t);

    // Check the validity of a TLS relocation.  This is like assert.
    static inline void
    check_tls(const Relocate_info<32, false>*, size_t relnum,
	      const elfcpp::Rel<32, false>&, bool);
  };

  // Adjust TLS relocation type based on the options and whether this
  // is a local symbol.
  static unsigned int
  optimize_tls_reloc(const General_options*, bool is_local, int r_type);

  // Information about this specific target which we pass to the
  // general Target structure.
  static const Target::Target_info i386_info;
};

const Target::Target_info Target_i386::i386_info =
{
  32,			// size
  false,		// is_big_endian
  elfcpp::EM_386,	// machine_code
  false,		// has_make_symbol
  false,		// has_resolve,
  0x08048000,		// text_segment_address,
  0x1000,		// abi_pagesize
  0x1000		// common_pagesize
};

// Optimize the TLS relocation type based on what we know about the
// symbol.  IS_LOCAL is true if this symbol can be resolved entirely
// locally--i.e., does not have to be in the dynamic symbol table.

unsigned int
Target_i386::optimize_tls_reloc(const General_options* options, bool is_local,
				int r_type)
{
  // If we are generating a shared library, then we can't do anything
  // in the linker.
  if (options->is_shared())
    return r_type;

  switch (r_type)
    {
    case elfcpp::R_386_TLS_GD:
    case elfcpp::R_386_TLS_GOTDESC:
    case elfcpp::R_386_TLS_DESC_CALL:
      // These are Global-Dynamic which permits fully general TLS
      // access.  Since we know that we are generating an executable,
      // we can convert this to Initial-Exec.  If we also know that
      // this is a local symbol, we can further switch to Local-Exec.
      if (is_local)
	return elfcpp::R_386_TLS_LE_32;
      return elfcpp::R_386_TLS_IE_32;

    case elfcpp::R_386_TLS_LDM:
      // This is Local-Dynamic, which refers to a local symbol in the
      // dynamic TLS block.  Since we know that we generating an
      // executable, we can switch to Local-Exec.
      return elfcpp::R_386_TLS_LE_32;

    case elfcpp::R_386_TLS_LDO_32:
      // Another type of Local-Dynamic relocation.
      return elfcpp::R_386_TLS_LE;

    case elfcpp::R_386_TLS_IE:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_IE_32:
      // These are Initial-Exec relocs which get the thread offset
      // from the GOT.  If we know that we are linking against the
      // local symbol, we can switch to Local-Exec, which links the
      // thread offset into the instruction.
      if (is_local)
	return elfcpp::R_386_TLS_LE_32;
      return r_type;
	
    case elfcpp::R_386_TLS_LE:
    case elfcpp::R_386_TLS_LE_32:
      // When we already have Local-Exec, there is nothing further we
      // can do.
      return r_type;

    default:
      abort();
    }
}

// Scan a relocation for a local symbol.

inline void
Target_i386::Scan::local(const General_options& options,
			 Sized_object<32, false>* object,
			 const elfcpp::Rel<32, false>&, unsigned int r_type,
			 const elfcpp::Sym<32, false>&)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
      break;

    case elfcpp::R_386_32:
    case elfcpp::R_386_16:
    case elfcpp::R_386_8:
      // FIXME: If we are generating a shared object we need to copy
      // this relocation into the object.
      break;

    case elfcpp::R_386_PC32:
    case elfcpp::R_386_PC16:
    case elfcpp::R_386_PC8:
      break;

    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
	      program_name, object->name().c_str(), r_type);
      gold_exit(false);
      break;

    case elfcpp::R_386_TLS_IE:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:
    case elfcpp::R_386_TLS_GD:
    case elfcpp::R_386_TLS_LDM:
    case elfcpp::R_386_TLS_LDO_32:
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_LE_32:
    case elfcpp::R_386_TLS_GOTDESC:
    case elfcpp::R_386_TLS_DESC_CALL:
      r_type = Target_i386::optimize_tls_reloc(&options, true, r_type);
      switch (r_type)
	{
	case elfcpp::R_386_TLS_LE:
	case elfcpp::R_386_TLS_LE_32:
	  // FIXME: If generating a shared object, we need to copy
	  // this relocation into the object.
	  break;

	case elfcpp::R_386_TLS_IE:
	case elfcpp::R_386_TLS_GOTIE:
	case elfcpp::R_386_TLS_GD:
	case elfcpp::R_386_TLS_LDM:
	case elfcpp::R_386_TLS_LDO_32:
	case elfcpp::R_386_TLS_IE_32:
	case elfcpp::R_386_TLS_GOTDESC:
	case elfcpp::R_386_TLS_DESC_CALL:
	  fprintf(stderr,
		  _("%s: %s: unsupported reloc %u against local symbol\n"),
		  program_name, object->name().c_str(), r_type);
	  break;
	}
      break;

    case elfcpp::R_386_GOT32:
    case elfcpp::R_386_PLT32:
    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOTPC:
    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"),
	      program_name, object->name().c_str(), r_type);
      break;
    }
}

// Scan a relocation for a global symbol.

inline void
Target_i386::Scan::global(const General_options& options,
			  Sized_object<32, false>* object,
			  const elfcpp::Rel<32, false>&, unsigned int r_type,
			  Symbol* gsym)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY: 
      break;

    case elfcpp::R_386_32:
    case elfcpp::R_386_PC32:
    case elfcpp::R_386_16:
    case elfcpp::R_386_PC16:
    case elfcpp::R_386_8:
    case elfcpp::R_386_PC8:
      // FIXME: If we are generating a shared object we may need to
      // copy this relocation into the object.  If this symbol is
      // defined in a shared object, we may need to copy this
      // relocation in order to avoid a COPY relocation.
      break;

    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
	      program_name, object->name().c_str(), r_type);
      gold_exit(false);
      break;

    case elfcpp::R_386_TLS_IE:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:
    case elfcpp::R_386_TLS_GD:
    case elfcpp::R_386_TLS_LDM:
    case elfcpp::R_386_TLS_LDO_32:
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_LE_32:
    case elfcpp::R_386_TLS_GOTDESC:
    case elfcpp::R_386_TLS_DESC_CALL:
      r_type = Target_i386::optimize_tls_reloc(&options,
					       !gsym->in_dynsym(),
					       r_type);
      switch (r_type)
	{
	case elfcpp::R_386_TLS_LE:
	case elfcpp::R_386_TLS_LE_32:
	  // FIXME: If generating a shared object, we need to copy
	  // this relocation into the object.
	  break;

	case elfcpp::R_386_TLS_IE:
	case elfcpp::R_386_TLS_GOTIE:
	case elfcpp::R_386_TLS_GD:
	case elfcpp::R_386_TLS_LDM:
	case elfcpp::R_386_TLS_LDO_32:
	case elfcpp::R_386_TLS_IE_32:
	case elfcpp::R_386_TLS_GOTDESC:
	case elfcpp::R_386_TLS_DESC_CALL:
	  fprintf(stderr,
		  _("%s: %s: unsupported reloc %u against global symbol %s\n"),
		  program_name, object->name().c_str(), r_type, gsym->name());
	  break;
	}
      break;

    case elfcpp::R_386_GOT32:
    case elfcpp::R_386_PLT32:
    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOTPC:
    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      fprintf(stderr,
	      _("%s: %s: unsupported reloc %u against global symbol %s\n"),
	      program_name, object->name().c_str(), r_type, gsym->name());
      break;
    }
}

// Scan relocations for a section.

void
Target_i386::scan_relocs(const General_options& options,
			 Symbol_table* symtab,
			 Sized_object<32, false>* object,
			 unsigned int sh_type,
			 const unsigned char* prelocs,
			 size_t reloc_count,
			 size_t local_symbol_count,
			 const unsigned char* plocal_symbols,
			 Symbol** global_symbols)
{
  if (sh_type == elfcpp::SHT_RELA)
    {
      fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"),
	      program_name, object->name().c_str());
      gold_exit(false);
    }

  gold::scan_relocs<32, false, elfcpp::SHT_REL, Target_i386::Scan>(
    options,
    symtab,
    object,
    prelocs,
    reloc_count,
    local_symbol_count,
    plocal_symbols,
    global_symbols);
}

// Perform a relocation.

inline void
Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
				size_t relnum,
				const elfcpp::Rel<32, false>& rel,
				unsigned int r_type,
				Sized_symbol<32>* gsym,
				elfcpp::Elf_types<32>::Elf_Addr value,
				unsigned char* view,
				elfcpp::Elf_types<32>::Elf_Addr address,
				off_t view_size)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
      break;

    case elfcpp::R_386_32:
      Relocate_functions<32, false>::rel32(view, value);
      break;

    case elfcpp::R_386_PC32:
      Relocate_functions<32, false>::pcrel32(view, value, address);
      break;

    case elfcpp::R_386_16:
      Relocate_functions<32, false>::rel16(view, value);
      break;

    case elfcpp::R_386_PC16:
      Relocate_functions<32, false>::pcrel16(view, value, address);
      break;

    case elfcpp::R_386_8:
      Relocate_functions<32, false>::rel8(view, value);
      break;

    case elfcpp::R_386_PC8:
      Relocate_functions<32, false>::pcrel8(view, value, address);
      break;

    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str(),
	      r_type);
      gold_exit(false);
      break;

    case elfcpp::R_386_TLS_IE:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:
    case elfcpp::R_386_TLS_GD:
    case elfcpp::R_386_TLS_LDM:
    case elfcpp::R_386_TLS_LDO_32:
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_LE_32:
    case elfcpp::R_386_TLS_GOTDESC:
    case elfcpp::R_386_TLS_DESC_CALL:
      Target_i386::Relocate::relocate_tls(relinfo, relnum, rel, r_type,
					  gsym, value, view, address,
					  view_size);
      break;

    case elfcpp::R_386_GOT32:
    case elfcpp::R_386_PLT32:
    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOTPC:
    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str(),
	      r_type);
      // gold_exit(false);
      break;
    }
}

// Perform a TLS relocation.

inline void
Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
				    size_t relnum,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int r_type,
				    Sized_symbol<32>* gsym,
				    elfcpp::Elf_types<32>::Elf_Addr value,
				    unsigned char* view,
				    elfcpp::Elf_types<32>::Elf_Addr,
				    off_t view_size)
{
  Output_segment* tls_segment = relinfo->layout->tls_segment();
  if (tls_segment == NULL)
    {
      fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str());
      gold_exit(false);
    }

  const bool is_local = gsym == NULL || !gsym->in_dynsym();
  const unsigned int opt_r_type =
    Target_i386::optimize_tls_reloc(relinfo->options, is_local, r_type);
  switch (r_type)
    {
    case elfcpp::R_386_TLS_LE_32:
      value = tls_segment->vaddr() + tls_segment->memsz() - value;
      Relocate_functions<32, false>::rel32(view, value);
      break;

    case elfcpp::R_386_TLS_LE:
      value = value - (tls_segment->vaddr() + tls_segment->memsz());
      Relocate_functions<32, false>::rel32(view, value);
      break;

    case elfcpp::R_386_TLS_IE:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_IE_32:
      if (opt_r_type == elfcpp::R_386_TLS_LE_32)
	{
	  Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
					      rel, r_type, value, view,
					      view_size);
	  break;
	}
      fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str(),
	      r_type);
      // gold_exit(false);
      break;

    case elfcpp::R_386_TLS_GD:
    case elfcpp::R_386_TLS_LDM:
    case elfcpp::R_386_TLS_LDO_32:
    case elfcpp::R_386_TLS_GOTDESC:
    case elfcpp::R_386_TLS_DESC_CALL:
      fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str(),
	      r_type);
      // gold_exit(false);
      break;
    }
}

// Do a relocation in which we convert a TLS Initial-Exec to a
// Local-Exec.

inline void
Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
				    size_t relnum,
				    Output_segment* tls_segment,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int r_type,
				    elfcpp::Elf_types<32>::Elf_Addr value,
				    unsigned char* view,
				    off_t view_size)
{
  // We have to actually change the instructions, which means that we
  // need to examine the opcodes to figure out which instruction we
  // are looking at.
  if (r_type == elfcpp::R_386_TLS_IE)
    {
      // movl %gs:XX,%eax  ==>  movl $YY,%eax
      // movl %gs:XX,%reg  ==>  movl $YY,%reg
      // addl %gs:XX,%reg  ==>  addl $YY,%reg
      Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1);
      Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);

      unsigned char op1 = view[-1];
      if (op1 == 0xa1)
	{
	  // movl XX,%eax  ==>  movl $YY,%eax
	  view[-1] = 0xb8;
	}
      else
	{
	  Target_i386::Relocate::check_range(relinfo, relnum, rel,
					     view_size, -2);

	  unsigned char op2 = view[-2];
	  if (op2 == 0x8b)
	    {
	      // movl XX,%reg  ==>  movl $YY,%reg
	      Target_i386::Relocate::check_tls(relinfo, relnum, rel,
					       (op1 & 0xc7) == 0x05);
	      view[-2] = 0xc7;
	      view[-1] = 0xc0 | ((op1 >> 3) & 7);
	    }
	  else if (op2 == 0x03)
	    {
	      // addl XX,%reg  ==>  addl $YY,%reg
	      Target_i386::Relocate::check_tls(relinfo, relnum, rel,
					       (op1 & 0xc7) == 0x05);
	      view[-2] = 0x81;
	      view[-1] = 0xc0 | ((op1 >> 3) & 7);
	    }
	  else
	    Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
	}
    }
  else
    {
      // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
      // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
      // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
      Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
      Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);

      unsigned char op1 = view[-1];
      unsigned char op2 = view[-2];
      Target_i386::Relocate::check_tls(relinfo, relnum, rel,
				       (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
      if (op2 == 0x8b)
	{
	  // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
	  view[-2] = 0xc7;
	  view[-1] = 0xc0 | ((op1 >> 3) & 7);
	}
      else if (op2 == 0x2b)
	{
	  // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
	  view[-2] = 0x81;
	  view[-1] = 0xe8 | ((op1 >> 3) & 7);
	}
      else if (op2 == 0x03)
	{
	  // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
	  view[-2] = 0x81;
	  view[-1] = 0xc0 | ((op1 >> 3) & 7);
	}
      else
	Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
    }

  if (r_type == elfcpp::R_386_TLS_IE_32)
    value = tls_segment->vaddr() + tls_segment->memsz() - value;
  else // elfcpp::R_386_TLS_IE, elfcpp::R_386_TLS_GOTIE
    value = value - (tls_segment->vaddr() + tls_segment->memsz());

  Relocate_functions<32, false>::rel32(view, value);
}

// Check the range for a TLS relocation.

inline void
Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo,
				   size_t relnum,
				   const elfcpp::Rel<32, false>& rel,
				   off_t view_size, off_t off)
{
  off_t offset = rel.get_r_offset() + off;
  if (offset < 0 || offset > view_size)
    {
      fprintf(stderr, _("%s: %s: TLS relocation out of range\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str());
      gold_exit(false);
    }
}

// Check the validity of a TLS relocation.  This is like assert.

inline void
Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo,
				 size_t relnum,
				 const elfcpp::Rel<32, false>& rel,
				 bool valid)
{
  if (!valid)
    {
      fprintf(stderr,
	      _("%s: %s: TLS relocation against invalid instruction\n"),
	      program_name,
	      relinfo->location(relnum, rel.get_r_offset()).c_str());
      gold_exit(false);
    }
}

// Relocate section data.

void
Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
			      unsigned int sh_type,
			      const unsigned char* prelocs,
			      size_t reloc_count,
			      unsigned char* view,
			      elfcpp::Elf_types<32>::Elf_Addr address,
			      off_t view_size)
{
  assert(sh_type == elfcpp::SHT_REL);

  gold::relocate_section<32, false, elfcpp::SHT_REL, Target_i386::Relocate>(
    relinfo,
    prelocs,
    reloc_count,
    view,
    address,
    view_size);
}

// The i386 target.

Target_i386 target_i386;

// The selector for i386 object files.

class Target_selector_i386 : public Target_selector
{
public:
  Target_selector_i386()
    : Target_selector(elfcpp::EM_386, 32, false)
  { }

  Target*
  recognize(int machine, int osabi, int abiversion) const;
};

// Recognize an i386 object file when we already know that the machine
// number is EM_386.

Target*
Target_selector_i386::recognize(int, int, int) const
{
  return &target_i386;
}

Target_selector_i386 target_selector_i386;

} // End anonymous namespace.