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[/] [open8_urisc/] [trunk/] [gnu/] [binutils/] [gold/] [i386.cc] - Blame information for rev 160

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1 27 khays
// i386.cc -- i386 target support for gold.
2
 
3 159 khays
// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 27 khays
// 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"
28 159 khays
#include "dwarf.h"
29 27 khays
#include "parameters.h"
30
#include "reloc.h"
31
#include "i386.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 "gc.h"
43
 
44
namespace
45
{
46
 
47
using namespace gold;
48
 
49
// A class to handle the PLT data.
50
 
51
class Output_data_plt_i386 : public Output_section_data
52
{
53
 public:
54
  typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
55
 
56 159 khays
  Output_data_plt_i386(Layout*, Output_data_space*, Output_data_space*);
57 27 khays
 
58
  // Add an entry to the PLT.
59
  void
60 159 khays
  add_entry(Symbol_table*, Layout*, Symbol* gsym);
61 27 khays
 
62
  // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
63
  unsigned int
64 159 khays
  add_local_ifunc_entry(Symbol_table*, Layout*,
65
                        Sized_relobj_file<32, false>* relobj,
66 27 khays
                        unsigned int local_sym_index);
67
 
68
  // Return the .rel.plt section data.
69
  Reloc_section*
70
  rel_plt() const
71
  { return this->rel_; }
72
 
73
  // Return where the TLS_DESC relocations should go.
74
  Reloc_section*
75
  rel_tls_desc(Layout*);
76
 
77 159 khays
  // Return where the IRELATIVE relocations should go.
78
  Reloc_section*
79
  rel_irelative(Symbol_table*, Layout*);
80
 
81
  // Return whether we created a section for IRELATIVE relocations.
82
  bool
83
  has_irelative_section() const
84
  { return this->irelative_rel_ != NULL; }
85
 
86 27 khays
  // Return the number of PLT entries.
87
  unsigned int
88
  entry_count() const
89 159 khays
  { return this->count_ + this->irelative_count_; }
90 27 khays
 
91
  // Return the offset of the first non-reserved PLT entry.
92
  static unsigned int
93
  first_plt_entry_offset()
94
  { return plt_entry_size; }
95
 
96
  // Return the size of a PLT entry.
97
  static unsigned int
98
  get_plt_entry_size()
99
  { return plt_entry_size; }
100
 
101 159 khays
  // Return the PLT address to use for a global symbol.
102
  uint64_t
103
  address_for_global(const Symbol*);
104
 
105
  // Return the PLT address to use for a local symbol.
106
  uint64_t
107
  address_for_local(const Relobj*, unsigned int symndx);
108
 
109 27 khays
 protected:
110
  void
111
  do_adjust_output_section(Output_section* os);
112
 
113
  // Write to a map file.
114
  void
115
  do_print_to_mapfile(Mapfile* mapfile) const
116
  { mapfile->print_output_data(this, _("** PLT")); }
117
 
118
 private:
119
  // The size of an entry in the PLT.
120
  static const int plt_entry_size = 16;
121
 
122
  // The first entry in the PLT for an executable.
123 159 khays
  static const unsigned char exec_first_plt_entry[plt_entry_size];
124 27 khays
 
125
  // The first entry in the PLT for a shared object.
126 159 khays
  static const unsigned char dyn_first_plt_entry[plt_entry_size];
127 27 khays
 
128
  // Other entries in the PLT for an executable.
129 159 khays
  static const unsigned char exec_plt_entry[plt_entry_size];
130 27 khays
 
131
  // Other entries in the PLT for a shared object.
132 159 khays
  static const unsigned char dyn_plt_entry[plt_entry_size];
133 27 khays
 
134 159 khays
  // The .eh_frame unwind information for the PLT.
135
  static const int plt_eh_frame_cie_size = 16;
136
  static const int plt_eh_frame_fde_size = 32;
137
  static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
138
  static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
139
 
140 27 khays
  // Set the final size.
141
  void
142
  set_final_data_size()
143 159 khays
  {
144
    this->set_data_size((this->count_ + this->irelative_count_ + 1)
145
                        * plt_entry_size);
146
  }
147 27 khays
 
148
  // Write out the PLT data.
149
  void
150
  do_write(Output_file*);
151
 
152
  // We keep a list of global STT_GNU_IFUNC symbols, each with its
153
  // offset in the GOT.
154
  struct Global_ifunc
155
  {
156
    Symbol* sym;
157
    unsigned int got_offset;
158
  };
159
 
160
  // We keep a list of local STT_GNU_IFUNC symbols, each with its
161
  // offset in the GOT.
162
  struct Local_ifunc
163
  {
164
    Sized_relobj_file<32, false>* object;
165
    unsigned int local_sym_index;
166
    unsigned int got_offset;
167
  };
168
 
169 159 khays
  // A pointer to the Layout class, so that we can find the .dynamic
170
  // section when we write out the GOT PLT section.
171
  Layout* layout_;
172 27 khays
  // The reloc section.
173
  Reloc_section* rel_;
174
  // The TLS_DESC relocations, if necessary.  These must follow the
175
  // regular PLT relocs.
176
  Reloc_section* tls_desc_rel_;
177 159 khays
  // The IRELATIVE relocations, if necessary.  These must follow the
178
  // regular relocatoins and the TLS_DESC relocations.
179
  Reloc_section* irelative_rel_;
180 27 khays
  // The .got.plt section.
181
  Output_data_space* got_plt_;
182 159 khays
  // The part of the .got.plt section used for IRELATIVE relocs.
183
  Output_data_space* got_irelative_;
184 27 khays
  // The number of PLT entries.
185
  unsigned int count_;
186 159 khays
  // Number of PLT entries with R_386_IRELATIVE relocs.  These follow
187
  // the regular PLT entries.
188
  unsigned int irelative_count_;
189 27 khays
  // Global STT_GNU_IFUNC symbols.
190
  std::vector<Global_ifunc> global_ifuncs_;
191
  // Local STT_GNU_IFUNC symbols.
192
  std::vector<Local_ifunc> local_ifuncs_;
193
};
194
 
195
// The i386 target class.
196
// TLS info comes from
197
//   http://people.redhat.com/drepper/tls.pdf
198
//   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
199
 
200 159 khays
class Target_i386 : public Sized_target<32, false>
201 27 khays
{
202
 public:
203
  typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
204
 
205
  Target_i386()
206 159 khays
    : Sized_target<32, false>(&i386_info),
207
      got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
208
      got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
209
      rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
210 27 khays
      got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
211
  { }
212
 
213
  // Process the relocations to determine unreferenced sections for 
214
  // garbage collection.
215
  void
216
  gc_process_relocs(Symbol_table* symtab,
217
                    Layout* layout,
218
                    Sized_relobj_file<32, false>* object,
219
                    unsigned int data_shndx,
220
                    unsigned int sh_type,
221
                    const unsigned char* prelocs,
222
                    size_t reloc_count,
223
                    Output_section* output_section,
224
                    bool needs_special_offset_handling,
225
                    size_t local_symbol_count,
226
                    const unsigned char* plocal_symbols);
227
 
228
  // Scan the relocations to look for symbol adjustments.
229
  void
230
  scan_relocs(Symbol_table* symtab,
231
              Layout* layout,
232
              Sized_relobj_file<32, false>* object,
233
              unsigned int data_shndx,
234
              unsigned int sh_type,
235
              const unsigned char* prelocs,
236
              size_t reloc_count,
237
              Output_section* output_section,
238
              bool needs_special_offset_handling,
239
              size_t local_symbol_count,
240
              const unsigned char* plocal_symbols);
241
 
242
  // Finalize the sections.
243
  void
244
  do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
245
 
246
  // Return the value to use for a dynamic which requires special
247
  // treatment.
248
  uint64_t
249
  do_dynsym_value(const Symbol*) const;
250
 
251
  // Relocate a section.
252
  void
253
  relocate_section(const Relocate_info<32, false>*,
254
                   unsigned int sh_type,
255
                   const unsigned char* prelocs,
256
                   size_t reloc_count,
257
                   Output_section* output_section,
258
                   bool needs_special_offset_handling,
259
                   unsigned char* view,
260
                   elfcpp::Elf_types<32>::Elf_Addr view_address,
261
                   section_size_type view_size,
262
                   const Reloc_symbol_changes*);
263
 
264
  // Scan the relocs during a relocatable link.
265
  void
266
  scan_relocatable_relocs(Symbol_table* symtab,
267
                          Layout* layout,
268
                          Sized_relobj_file<32, false>* object,
269
                          unsigned int data_shndx,
270
                          unsigned int sh_type,
271
                          const unsigned char* prelocs,
272
                          size_t reloc_count,
273
                          Output_section* output_section,
274
                          bool needs_special_offset_handling,
275
                          size_t local_symbol_count,
276
                          const unsigned char* plocal_symbols,
277
                          Relocatable_relocs*);
278
 
279
  // Relocate a section during a relocatable link.
280
  void
281
  relocate_for_relocatable(const Relocate_info<32, false>*,
282
                           unsigned int sh_type,
283
                           const unsigned char* prelocs,
284
                           size_t reloc_count,
285
                           Output_section* output_section,
286
                           off_t offset_in_output_section,
287
                           const Relocatable_relocs*,
288
                           unsigned char* view,
289
                           elfcpp::Elf_types<32>::Elf_Addr view_address,
290
                           section_size_type view_size,
291
                           unsigned char* reloc_view,
292
                           section_size_type reloc_view_size);
293
 
294
  // Return a string used to fill a code section with nops.
295
  std::string
296
  do_code_fill(section_size_type length) const;
297
 
298
  // Return whether SYM is defined by the ABI.
299
  bool
300
  do_is_defined_by_abi(const Symbol* sym) const
301
  { return strcmp(sym->name(), "___tls_get_addr") == 0; }
302
 
303
  // Return whether a symbol name implies a local label.  The UnixWare
304
  // 2.1 cc generates temporary symbols that start with .X, so we
305
  // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
306
  // If so, we should move the .X recognition into
307
  // Target::do_is_local_label_name.
308
  bool
309
  do_is_local_label_name(const char* name) const
310
  {
311
    if (name[0] == '.' && name[1] == 'X')
312
      return true;
313
    return Target::do_is_local_label_name(name);
314
  }
315
 
316 159 khays
  // Return the PLT address to use for a global symbol.
317
  uint64_t
318
  do_plt_address_for_global(const Symbol* gsym) const
319
  { return this->plt_section()->address_for_global(gsym); }
320 27 khays
 
321 159 khays
  uint64_t
322
  do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
323
  { return this->plt_section()->address_for_local(relobj, symndx); }
324 27 khays
 
325 159 khays
  // We can tell whether we take the address of a function.
326
  inline bool
327
  do_can_check_for_function_pointers() const
328
  { return true; }
329
 
330
  // Return the base for a DW_EH_PE_datarel encoding.
331
  uint64_t
332
  do_ehframe_datarel_base() const;
333
 
334 27 khays
  // Return whether SYM is call to a non-split function.
335
  bool
336
  do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
337
 
338
  // Adjust -fsplit-stack code which calls non-split-stack code.
339
  void
340
  do_calls_non_split(Relobj* object, unsigned int shndx,
341
                     section_offset_type fnoffset, section_size_type fnsize,
342
                     unsigned char* view, section_size_type view_size,
343
                     std::string* from, std::string* to) const;
344
 
345
  // Return the size of the GOT section.
346
  section_size_type
347
  got_size() const
348
  {
349
    gold_assert(this->got_ != NULL);
350
    return this->got_->data_size();
351
  }
352
 
353
  // Return the number of entries in the GOT.
354
  unsigned int
355
  got_entry_count() const
356
  {
357
    if (this->got_ == NULL)
358
      return 0;
359
    return this->got_size() / 4;
360
  }
361
 
362
  // Return the number of entries in the PLT.
363
  unsigned int
364
  plt_entry_count() const;
365
 
366
  // Return the offset of the first non-reserved PLT entry.
367
  unsigned int
368
  first_plt_entry_offset() const;
369
 
370
  // Return the size of each PLT entry.
371
  unsigned int
372
  plt_entry_size() const;
373
 
374
 private:
375
  // The class which scans relocations.
376
  struct Scan
377
  {
378
    static inline int
379
 
380
    get_reference_flags(unsigned int r_type);
381
 
382
    inline void
383
    local(Symbol_table* symtab, Layout* layout, Target_i386* target,
384
          Sized_relobj_file<32, false>* object,
385
          unsigned int data_shndx,
386
          Output_section* output_section,
387
          const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
388
          const elfcpp::Sym<32, false>& lsym);
389
 
390
    inline void
391
    global(Symbol_table* symtab, Layout* layout, Target_i386* target,
392
           Sized_relobj_file<32, false>* object,
393
           unsigned int data_shndx,
394
           Output_section* output_section,
395
           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
396
           Symbol* gsym);
397
 
398
    inline bool
399
    local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
400
                                        Target_i386* target,
401
                                        Sized_relobj_file<32, false>* object,
402
                                        unsigned int data_shndx,
403
                                        Output_section* output_section,
404
                                        const elfcpp::Rel<32, false>& reloc,
405
                                        unsigned int r_type,
406
                                        const elfcpp::Sym<32, false>& lsym);
407
 
408
    inline bool
409
    global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
410
                                         Target_i386* target,
411
                                         Sized_relobj_file<32, false>* object,
412
                                         unsigned int data_shndx,
413
                                         Output_section* output_section,
414
                                         const elfcpp::Rel<32, false>& reloc,
415
                                         unsigned int r_type,
416
                                         Symbol* gsym);
417
 
418
    inline bool
419
    possible_function_pointer_reloc(unsigned int r_type);
420
 
421
    bool
422
    reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
423
                              unsigned int r_type);
424
 
425
    static void
426
    unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
427
 
428
    static void
429
    unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
430
                             Symbol*);
431
  };
432
 
433
  // The class which implements relocation.
434
  class Relocate
435
  {
436
   public:
437
    Relocate()
438
      : skip_call_tls_get_addr_(false),
439
        local_dynamic_type_(LOCAL_DYNAMIC_NONE)
440
    { }
441
 
442
    ~Relocate()
443
    {
444
      if (this->skip_call_tls_get_addr_)
445
        {
446
          // FIXME: This needs to specify the location somehow.
447
          gold_error(_("missing expected TLS relocation"));
448
        }
449
    }
450
 
451
    // Return whether the static relocation needs to be applied.
452
    inline bool
453
    should_apply_static_reloc(const Sized_symbol<32>* gsym,
454
                              unsigned int r_type,
455
                              bool is_32bit,
456
                              Output_section* output_section);
457
 
458
    // Do a relocation.  Return false if the caller should not issue
459
    // any warnings about this relocation.
460
    inline bool
461
    relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
462
             size_t relnum, const elfcpp::Rel<32, false>&,
463
             unsigned int r_type, const Sized_symbol<32>*,
464
             const Symbol_value<32>*,
465
             unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
466
             section_size_type);
467
 
468
   private:
469
    // Do a TLS relocation.
470
    inline void
471
    relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
472
                 size_t relnum, const elfcpp::Rel<32, false>&,
473
                 unsigned int r_type, const Sized_symbol<32>*,
474
                 const Symbol_value<32>*,
475
                 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
476
                 section_size_type);
477
 
478
    // Do a TLS General-Dynamic to Initial-Exec transition.
479
    inline void
480
    tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
481
                 Output_segment* tls_segment,
482
                 const elfcpp::Rel<32, false>&, unsigned int r_type,
483
                 elfcpp::Elf_types<32>::Elf_Addr value,
484
                 unsigned char* view,
485
                 section_size_type view_size);
486
 
487
    // Do a TLS General-Dynamic to Local-Exec transition.
488
    inline void
489
    tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
490
                 Output_segment* tls_segment,
491
                 const elfcpp::Rel<32, false>&, unsigned int r_type,
492
                 elfcpp::Elf_types<32>::Elf_Addr value,
493
                 unsigned char* view,
494
                 section_size_type view_size);
495
 
496
    // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
497
    // transition.
498
    inline void
499
    tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
500
                      Output_segment* tls_segment,
501
                      const elfcpp::Rel<32, false>&, unsigned int r_type,
502
                      elfcpp::Elf_types<32>::Elf_Addr value,
503
                      unsigned char* view,
504
                      section_size_type view_size);
505
 
506
    // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
507
    // transition.
508
    inline void
509
    tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
510
                      Output_segment* tls_segment,
511
                      const elfcpp::Rel<32, false>&, unsigned int r_type,
512
                      elfcpp::Elf_types<32>::Elf_Addr value,
513
                      unsigned char* view,
514
                      section_size_type view_size);
515
 
516
    // Do a TLS Local-Dynamic to Local-Exec transition.
517
    inline void
518
    tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
519
                 Output_segment* tls_segment,
520
                 const elfcpp::Rel<32, false>&, unsigned int r_type,
521
                 elfcpp::Elf_types<32>::Elf_Addr value,
522
                 unsigned char* view,
523
                 section_size_type view_size);
524
 
525
    // Do a TLS Initial-Exec to Local-Exec transition.
526
    static inline void
527
    tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
528
                 Output_segment* tls_segment,
529
                 const elfcpp::Rel<32, false>&, unsigned int r_type,
530
                 elfcpp::Elf_types<32>::Elf_Addr value,
531
                 unsigned char* view,
532
                 section_size_type view_size);
533
 
534
    // We need to keep track of which type of local dynamic relocation
535
    // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
536
    enum Local_dynamic_type
537
    {
538
      LOCAL_DYNAMIC_NONE,
539
      LOCAL_DYNAMIC_SUN,
540
      LOCAL_DYNAMIC_GNU
541
    };
542
 
543
    // This is set if we should skip the next reloc, which should be a
544
    // PLT32 reloc against ___tls_get_addr.
545
    bool skip_call_tls_get_addr_;
546
    // The type of local dynamic relocation we have seen in the section
547
    // being relocated, if any.
548
    Local_dynamic_type local_dynamic_type_;
549
  };
550
 
551
  // A class which returns the size required for a relocation type,
552
  // used while scanning relocs during a relocatable link.
553
  class Relocatable_size_for_reloc
554
  {
555
   public:
556
    unsigned int
557
    get_size_for_reloc(unsigned int, Relobj*);
558
  };
559
 
560
  // Adjust TLS relocation type based on the options and whether this
561
  // is a local symbol.
562
  static tls::Tls_optimization
563
  optimize_tls_reloc(bool is_final, int r_type);
564
 
565
  // Get the GOT section, creating it if necessary.
566
  Output_data_got<32, false>*
567
  got_section(Symbol_table*, Layout*);
568
 
569
  // Get the GOT PLT section.
570
  Output_data_space*
571
  got_plt_section() const
572
  {
573
    gold_assert(this->got_plt_ != NULL);
574
    return this->got_plt_;
575
  }
576
 
577
  // Get the GOT section for TLSDESC entries.
578
  Output_data_got<32, false>*
579
  got_tlsdesc_section() const
580
  {
581
    gold_assert(this->got_tlsdesc_ != NULL);
582
    return this->got_tlsdesc_;
583
  }
584
 
585
  // Create the PLT section.
586
  void
587
  make_plt_section(Symbol_table* symtab, Layout* layout);
588
 
589
  // Create a PLT entry for a global symbol.
590
  void
591
  make_plt_entry(Symbol_table*, Layout*, Symbol*);
592
 
593
  // Create a PLT entry for a local STT_GNU_IFUNC symbol.
594
  void
595
  make_local_ifunc_plt_entry(Symbol_table*, Layout*,
596
                             Sized_relobj_file<32, false>* relobj,
597
                             unsigned int local_sym_index);
598
 
599
  // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
600
  void
601
  define_tls_base_symbol(Symbol_table*, Layout*);
602
 
603
  // Create a GOT entry for the TLS module index.
604
  unsigned int
605
  got_mod_index_entry(Symbol_table* symtab, Layout* layout,
606
                      Sized_relobj_file<32, false>* object);
607
 
608
  // Get the PLT section.
609
  Output_data_plt_i386*
610
  plt_section() const
611
  {
612
    gold_assert(this->plt_ != NULL);
613
    return this->plt_;
614
  }
615
 
616
  // Get the dynamic reloc section, creating it if necessary.
617
  Reloc_section*
618
  rel_dyn_section(Layout*);
619
 
620
  // Get the section to use for TLS_DESC relocations.
621
  Reloc_section*
622
  rel_tls_desc_section(Layout*) const;
623
 
624 159 khays
  // Get the section to use for IRELATIVE relocations.
625
  Reloc_section*
626
  rel_irelative_section(Layout*);
627
 
628 27 khays
  // Add a potential copy relocation.
629
  void
630
  copy_reloc(Symbol_table* symtab, Layout* layout,
631
             Sized_relobj_file<32, false>* object,
632
             unsigned int shndx, Output_section* output_section,
633
             Symbol* sym, const elfcpp::Rel<32, false>& reloc)
634
  {
635
    this->copy_relocs_.copy_reloc(symtab, layout,
636
                                  symtab->get_sized_symbol<32>(sym),
637
                                  object, shndx, output_section, reloc,
638
                                  this->rel_dyn_section(layout));
639
  }
640
 
641
  // Information about this specific target which we pass to the
642
  // general Target structure.
643
  static const Target::Target_info i386_info;
644
 
645
  // The types of GOT entries needed for this platform.
646
  // These values are exposed to the ABI in an incremental link.
647
  // Do not renumber existing values without changing the version
648
  // number of the .gnu_incremental_inputs section.
649
  enum Got_type
650
  {
651
    GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
652
    GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
653
    GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
654
    GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
655
    GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
656
  };
657
 
658
  // The GOT section.
659
  Output_data_got<32, false>* got_;
660
  // The PLT section.
661
  Output_data_plt_i386* plt_;
662
  // The GOT PLT section.
663
  Output_data_space* got_plt_;
664 159 khays
  // The GOT section for IRELATIVE relocations.
665
  Output_data_space* got_irelative_;
666 27 khays
  // The GOT section for TLSDESC relocations.
667
  Output_data_got<32, false>* got_tlsdesc_;
668
  // The _GLOBAL_OFFSET_TABLE_ symbol.
669
  Symbol* global_offset_table_;
670
  // The dynamic reloc section.
671
  Reloc_section* rel_dyn_;
672 159 khays
  // The section to use for IRELATIVE relocs.
673
  Reloc_section* rel_irelative_;
674 27 khays
  // Relocs saved to avoid a COPY reloc.
675
  Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
676
  // Space for variables copied with a COPY reloc.
677
  Output_data_space* dynbss_;
678
  // Offset of the GOT entry for the TLS module index.
679
  unsigned int got_mod_index_offset_;
680
  // True if the _TLS_MODULE_BASE_ symbol has been defined.
681
  bool tls_base_symbol_defined_;
682
};
683
 
684
const Target::Target_info Target_i386::i386_info =
685
{
686
  32,                   // size
687
  false,                // is_big_endian
688
  elfcpp::EM_386,       // machine_code
689
  false,                // has_make_symbol
690
  false,                // has_resolve
691
  true,                 // has_code_fill
692
  true,                 // is_default_stack_executable
693 159 khays
  true,                 // can_icf_inline_merge_sections
694 27 khays
  '\0',                 // wrap_char
695
  "/usr/lib/libc.so.1", // dynamic_linker
696
  0x08048000,           // default_text_segment_address
697
  0x1000,               // abi_pagesize (overridable by -z max-page-size)
698
  0x1000,               // common_pagesize (overridable by -z common-page-size)
699
  elfcpp::SHN_UNDEF,    // small_common_shndx
700
  elfcpp::SHN_UNDEF,    // large_common_shndx
701
  0,                     // small_common_section_flags
702
  0,                     // large_common_section_flags
703
  NULL,                 // attributes_section
704
  NULL                  // attributes_vendor
705
};
706
 
707
// Get the GOT section, creating it if necessary.
708
 
709
Output_data_got<32, false>*
710
Target_i386::got_section(Symbol_table* symtab, Layout* layout)
711
{
712
  if (this->got_ == NULL)
713
    {
714
      gold_assert(symtab != NULL && layout != NULL);
715
 
716
      this->got_ = new Output_data_got<32, false>();
717
 
718 159 khays
      // When using -z now, we can treat .got.plt as a relro section.
719
      // Without -z now, it is modified after program startup by lazy
720
      // PLT relocations.
721
      bool is_got_plt_relro = parameters->options().now();
722
      Output_section_order got_order = (is_got_plt_relro
723
                                        ? ORDER_RELRO
724
                                        : ORDER_RELRO_LAST);
725
      Output_section_order got_plt_order = (is_got_plt_relro
726
                                            ? ORDER_RELRO
727
                                            : ORDER_NON_RELRO_FIRST);
728
 
729 27 khays
      layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
730
                                      (elfcpp::SHF_ALLOC
731
                                       | elfcpp::SHF_WRITE),
732 159 khays
                                      this->got_, got_order, true);
733 27 khays
 
734
      this->got_plt_ = new Output_data_space(4, "** GOT PLT");
735
      layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
736
                                      (elfcpp::SHF_ALLOC
737
                                       | elfcpp::SHF_WRITE),
738 159 khays
                                      this->got_plt_, got_plt_order,
739
                                      is_got_plt_relro);
740 27 khays
 
741
      // The first three entries are reserved.
742
      this->got_plt_->set_current_data_size(3 * 4);
743
 
744 159 khays
      if (!is_got_plt_relro)
745
        {
746
          // Those bytes can go into the relro segment.
747
          layout->increase_relro(3 * 4);
748
        }
749 27 khays
 
750
      // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
751
      this->global_offset_table_ =
752
        symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
753
                                      Symbol_table::PREDEFINED,
754
                                      this->got_plt_,
755
                                      0, 0, elfcpp::STT_OBJECT,
756
                                      elfcpp::STB_LOCAL,
757
                                      elfcpp::STV_HIDDEN, 0,
758
                                      false, false);
759
 
760 159 khays
      // If there are any IRELATIVE relocations, they get GOT entries
761
      // in .got.plt after the jump slot relocations.
762
      this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
763
      layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
764
                                      (elfcpp::SHF_ALLOC
765
                                       | elfcpp::SHF_WRITE),
766
                                      this->got_irelative_,
767
                                      got_plt_order, is_got_plt_relro);
768
 
769 27 khays
      // If there are any TLSDESC relocations, they get GOT entries in
770
      // .got.plt after the jump slot entries.
771
      this->got_tlsdesc_ = new Output_data_got<32, false>();
772
      layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
773
                                      (elfcpp::SHF_ALLOC
774
                                       | elfcpp::SHF_WRITE),
775
                                      this->got_tlsdesc_,
776 159 khays
                                      got_plt_order, is_got_plt_relro);
777 27 khays
    }
778
 
779
  return this->got_;
780
}
781
 
782
// Get the dynamic reloc section, creating it if necessary.
783
 
784
Target_i386::Reloc_section*
785
Target_i386::rel_dyn_section(Layout* layout)
786
{
787
  if (this->rel_dyn_ == NULL)
788
    {
789
      gold_assert(layout != NULL);
790
      this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
791
      layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
792
                                      elfcpp::SHF_ALLOC, this->rel_dyn_,
793
                                      ORDER_DYNAMIC_RELOCS, false);
794
    }
795
  return this->rel_dyn_;
796
}
797
 
798 159 khays
// Get the section to use for IRELATIVE relocs, creating it if
799
// necessary.  These go in .rel.dyn, but only after all other dynamic
800
// relocations.  They need to follow the other dynamic relocations so
801
// that they can refer to global variables initialized by those
802
// relocs.
803
 
804
Target_i386::Reloc_section*
805
Target_i386::rel_irelative_section(Layout* layout)
806
{
807
  if (this->rel_irelative_ == NULL)
808
    {
809
      // Make sure we have already create the dynamic reloc section.
810
      this->rel_dyn_section(layout);
811
      this->rel_irelative_ = new Reloc_section(false);
812
      layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
813
                                      elfcpp::SHF_ALLOC, this->rel_irelative_,
814
                                      ORDER_DYNAMIC_RELOCS, false);
815
      gold_assert(this->rel_dyn_->output_section()
816
                  == this->rel_irelative_->output_section());
817
    }
818
  return this->rel_irelative_;
819
}
820
 
821 27 khays
// Create the PLT section.  The ordinary .got section is an argument,
822
// since we need to refer to the start.  We also create our own .got
823
// section just for PLT entries.
824
 
825 159 khays
Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
826
                                           Output_data_space* got_plt,
827
                                           Output_data_space* got_irelative)
828
  : Output_section_data(16), layout_(layout), tls_desc_rel_(NULL),
829
    irelative_rel_(NULL), got_plt_(got_plt), got_irelative_(got_irelative),
830
    count_(0), irelative_count_(0), global_ifuncs_(), local_ifuncs_()
831 27 khays
{
832
  this->rel_ = new Reloc_section(false);
833
  layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
834
                                  elfcpp::SHF_ALLOC, this->rel_,
835
                                  ORDER_DYNAMIC_PLT_RELOCS, false);
836
 
837 159 khays
  // Add unwind information if requested.
838
  if (parameters->options().ld_generated_unwind_info())
839
    layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
840
                                 plt_eh_frame_fde, plt_eh_frame_fde_size);
841 27 khays
}
842
 
843
void
844
Output_data_plt_i386::do_adjust_output_section(Output_section* os)
845
{
846
  // UnixWare sets the entsize of .plt to 4, and so does the old GNU
847
  // linker, and so do we.
848
  os->set_entsize(4);
849
}
850
 
851
// Add an entry to the PLT.
852
 
853
void
854 159 khays
Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
855
                                Symbol* gsym)
856 27 khays
{
857
  gold_assert(!gsym->has_plt_offset());
858
 
859
  // Every PLT entry needs a reloc.
860
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
861
      && gsym->can_use_relative_reloc(false))
862
    {
863 159 khays
      gsym->set_plt_offset(this->irelative_count_ * plt_entry_size);
864
      ++this->irelative_count_;
865
      section_offset_type got_offset =
866
        this->got_irelative_->current_data_size();
867
      this->got_irelative_->set_current_data_size(got_offset + 4);
868
      Reloc_section* rel = this->rel_irelative(symtab, layout);
869
      rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
870
                                        this->got_irelative_, got_offset);
871 27 khays
      struct Global_ifunc gi;
872
      gi.sym = gsym;
873
      gi.got_offset = got_offset;
874
      this->global_ifuncs_.push_back(gi);
875
    }
876
  else
877
    {
878 159 khays
      // When setting the PLT offset we skip the initial reserved PLT
879
      // entry.
880
      gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
881
 
882
      ++this->count_;
883
 
884
      section_offset_type got_offset = this->got_plt_->current_data_size();
885
 
886
      // Every PLT entry needs a GOT entry which points back to the
887
      // PLT entry (this will be changed by the dynamic linker,
888
      // normally lazily when the function is called).
889
      this->got_plt_->set_current_data_size(got_offset + 4);
890
 
891 27 khays
      gsym->set_needs_dynsym_entry();
892
      this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
893
                             got_offset);
894
    }
895
 
896
  // Note that we don't need to save the symbol.  The contents of the
897
  // PLT are independent of which symbols are used.  The symbols only
898
  // appear in the relocations.
899
}
900
 
901
// Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
902
// the PLT offset.
903
 
904
unsigned int
905
Output_data_plt_i386::add_local_ifunc_entry(
906 159 khays
    Symbol_table* symtab,
907
    Layout* layout,
908 27 khays
    Sized_relobj_file<32, false>* relobj,
909
    unsigned int local_sym_index)
910
{
911 159 khays
  unsigned int plt_offset = this->irelative_count_ * plt_entry_size;
912
  ++this->irelative_count_;
913 27 khays
 
914 159 khays
  section_offset_type got_offset = this->got_irelative_->current_data_size();
915 27 khays
 
916
  // Every PLT entry needs a GOT entry which points back to the PLT
917
  // entry.
918 159 khays
  this->got_irelative_->set_current_data_size(got_offset + 4);
919 27 khays
 
920
  // Every PLT entry needs a reloc.
921 159 khays
  Reloc_section* rel = this->rel_irelative(symtab, layout);
922
  rel->add_symbolless_local_addend(relobj, local_sym_index,
923
                                   elfcpp::R_386_IRELATIVE,
924
                                   this->got_irelative_, got_offset);
925 27 khays
 
926
  struct Local_ifunc li;
927
  li.object = relobj;
928
  li.local_sym_index = local_sym_index;
929
  li.got_offset = got_offset;
930
  this->local_ifuncs_.push_back(li);
931
 
932
  return plt_offset;
933
}
934
 
935
// Return where the TLS_DESC relocations should go, creating it if
936
// necessary. These follow the JUMP_SLOT relocations.
937
 
938
Output_data_plt_i386::Reloc_section*
939
Output_data_plt_i386::rel_tls_desc(Layout* layout)
940
{
941
  if (this->tls_desc_rel_ == NULL)
942
    {
943
      this->tls_desc_rel_ = new Reloc_section(false);
944
      layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
945
                                      elfcpp::SHF_ALLOC, this->tls_desc_rel_,
946
                                      ORDER_DYNAMIC_PLT_RELOCS, false);
947 159 khays
      gold_assert(this->tls_desc_rel_->output_section()
948
                  == this->rel_->output_section());
949 27 khays
    }
950
  return this->tls_desc_rel_;
951
}
952
 
953 159 khays
// Return where the IRELATIVE relocations should go in the PLT.  These
954
// follow the JUMP_SLOT and TLS_DESC relocations.
955
 
956
Output_data_plt_i386::Reloc_section*
957
Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
958
{
959
  if (this->irelative_rel_ == NULL)
960
    {
961
      // Make sure we have a place for the TLS_DESC relocations, in
962
      // case we see any later on.
963
      this->rel_tls_desc(layout);
964
      this->irelative_rel_ = new Reloc_section(false);
965
      layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
966
                                      elfcpp::SHF_ALLOC, this->irelative_rel_,
967
                                      ORDER_DYNAMIC_PLT_RELOCS, false);
968
      gold_assert(this->irelative_rel_->output_section()
969
                  == this->rel_->output_section());
970
 
971
      if (parameters->doing_static_link())
972
        {
973
          // A statically linked executable will only have a .rel.plt
974
          // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
975
          // symbols.  The library will use these symbols to locate
976
          // the IRELATIVE relocs at program startup time.
977
          symtab->define_in_output_data("__rel_iplt_start", NULL,
978
                                        Symbol_table::PREDEFINED,
979
                                        this->irelative_rel_, 0, 0,
980
                                        elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
981
                                        elfcpp::STV_HIDDEN, 0, false, true);
982
          symtab->define_in_output_data("__rel_iplt_end", NULL,
983
                                        Symbol_table::PREDEFINED,
984
                                        this->irelative_rel_, 0, 0,
985
                                        elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
986
                                        elfcpp::STV_HIDDEN, 0, true, true);
987
        }
988
    }
989
  return this->irelative_rel_;
990
}
991
 
992
// Return the PLT address to use for a global symbol.
993
 
994
uint64_t
995
Output_data_plt_i386::address_for_global(const Symbol* gsym)
996
{
997
  uint64_t offset = 0;
998
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
999
      && gsym->can_use_relative_reloc(false))
1000
    offset = (this->count_ + 1) * plt_entry_size;
1001
  return this->address() + offset;
1002
}
1003
 
1004
// Return the PLT address to use for a local symbol.  These are always
1005
// IRELATIVE relocs.
1006
 
1007
uint64_t
1008
Output_data_plt_i386::address_for_local(const Relobj*, unsigned int)
1009
{
1010
  return this->address() + (this->count_ + 1) * plt_entry_size;
1011
}
1012
 
1013 27 khays
// The first entry in the PLT for an executable.
1014
 
1015 159 khays
const unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
1016 27 khays
{
1017
  0xff, 0x35,   // pushl contents of memory address
1018
  0, 0, 0, 0,       // replaced with address of .got + 4
1019
  0xff, 0x25,   // jmp indirect
1020
  0, 0, 0, 0,       // replaced with address of .got + 8
1021
  0, 0, 0, 0        // unused
1022
};
1023
 
1024
// The first entry in the PLT for a shared object.
1025
 
1026 159 khays
const unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
1027 27 khays
{
1028
  0xff, 0xb3, 4, 0, 0, 0,  // pushl 4(%ebx)
1029
  0xff, 0xa3, 8, 0, 0, 0,  // jmp *8(%ebx)
1030
  0, 0, 0, 0                        // unused
1031
};
1032
 
1033
// Subsequent entries in the PLT for an executable.
1034
 
1035 159 khays
const unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
1036 27 khays
{
1037
  0xff, 0x25,   // jmp indirect
1038
  0, 0, 0, 0,       // replaced with address of symbol in .got
1039
  0x68,         // pushl immediate
1040
  0, 0, 0, 0,       // replaced with offset into relocation table
1041
  0xe9,         // jmp relative
1042
  0, 0, 0, 0        // replaced with offset to start of .plt
1043
};
1044
 
1045
// Subsequent entries in the PLT for a shared object.
1046
 
1047 159 khays
const unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
1048 27 khays
{
1049
  0xff, 0xa3,   // jmp *offset(%ebx)
1050
  0, 0, 0, 0,       // replaced with offset of symbol in .got
1051
  0x68,         // pushl immediate
1052
  0, 0, 0, 0,       // replaced with offset into relocation table
1053
  0xe9,         // jmp relative
1054
  0, 0, 0, 0        // replaced with offset to start of .plt
1055
};
1056
 
1057 159 khays
// The .eh_frame unwind information for the PLT.
1058
 
1059
const unsigned char
1060
Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1061
{
1062
  1,                            // CIE version.
1063
  'z',                          // Augmentation: augmentation size included.
1064
  'R',                          // Augmentation: FDE encoding included.
1065
  '\0',                         // End of augmentation string.
1066
  1,                            // Code alignment factor.
1067
  0x7c,                         // Data alignment factor.
1068
  8,                            // Return address column.
1069
  1,                            // Augmentation size.
1070
  (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1071
   | elfcpp::DW_EH_PE_sdata4),
1072
  elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1073
  elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1074
  elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1075
  elfcpp::DW_CFA_nop
1076
};
1077
 
1078
const unsigned char
1079
Output_data_plt_i386::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1080
{
1081
  0, 0, 0, 0,                               // Replaced with offset to .plt.
1082
  0, 0, 0, 0,                               // Replaced with size of .plt.
1083
  0,                                     // Augmentation size.
1084
  elfcpp::DW_CFA_def_cfa_offset, 8,     // DW_CFA_def_cfa_offset: 8.
1085
  elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1086
  elfcpp::DW_CFA_def_cfa_offset, 12,    // DW_CFA_def_cfa_offset: 12.
1087
  elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1088
  elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1089
  11,                                   // Block length.
1090
  elfcpp::DW_OP_breg4, 4,               // Push %esp + 4.
1091
  elfcpp::DW_OP_breg8, 0,                // Push %eip.
1092
  elfcpp::DW_OP_lit15,                  // Push 0xf.
1093
  elfcpp::DW_OP_and,                    // & (%eip & 0xf).
1094
  elfcpp::DW_OP_lit11,                  // Push 0xb.
1095
  elfcpp::DW_OP_ge,                     // >= ((%eip & 0xf) >= 0xb)
1096
  elfcpp::DW_OP_lit2,                   // Push 2.
1097
  elfcpp::DW_OP_shl,                    // << (((%eip & 0xf) >= 0xb) << 2)
1098
  elfcpp::DW_OP_plus,                   // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1099
  elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1100
  elfcpp::DW_CFA_nop,
1101
  elfcpp::DW_CFA_nop,
1102
  elfcpp::DW_CFA_nop
1103
};
1104
 
1105 27 khays
// Write out the PLT.  This uses the hand-coded instructions above,
1106
// and adjusts them as needed.  This is all specified by the i386 ELF
1107
// Processor Supplement.
1108
 
1109
void
1110
Output_data_plt_i386::do_write(Output_file* of)
1111
{
1112
  const off_t offset = this->offset();
1113
  const section_size_type oview_size =
1114
    convert_to_section_size_type(this->data_size());
1115
  unsigned char* const oview = of->get_output_view(offset, oview_size);
1116
 
1117
  const off_t got_file_offset = this->got_plt_->offset();
1118 159 khays
  gold_assert(parameters->incremental_update()
1119
              || (got_file_offset + this->got_plt_->data_size()
1120
                  == this->got_irelative_->offset()));
1121 27 khays
  const section_size_type got_size =
1122 159 khays
    convert_to_section_size_type(this->got_plt_->data_size()
1123
                                 + this->got_irelative_->data_size());
1124 27 khays
  unsigned char* const got_view = of->get_output_view(got_file_offset,
1125
                                                      got_size);
1126
 
1127
  unsigned char* pov = oview;
1128
 
1129
  elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1130
  elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1131
 
1132
  if (parameters->options().output_is_position_independent())
1133
    memcpy(pov, dyn_first_plt_entry, plt_entry_size);
1134
  else
1135
    {
1136
      memcpy(pov, exec_first_plt_entry, plt_entry_size);
1137
      elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1138
      elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1139
    }
1140
  pov += plt_entry_size;
1141
 
1142
  unsigned char* got_pov = got_view;
1143
 
1144 159 khays
  // The first entry in the GOT is the address of the .dynamic section
1145
  // aka the PT_DYNAMIC segment.  The next two entries are reserved.
1146
  // We saved space for them when we created the section in
1147
  // Target_i386::got_section.
1148
  Output_section* dynamic = this->layout_->dynamic_section();
1149
  uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1150
  elfcpp::Swap<32, false>::writeval(got_pov, dynamic_addr);
1151
  got_pov += 4;
1152
  memset(got_pov, 0, 8);
1153
  got_pov += 8;
1154 27 khays
 
1155
  const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1156
 
1157
  unsigned int plt_offset = plt_entry_size;
1158
  unsigned int plt_rel_offset = 0;
1159
  unsigned int got_offset = 12;
1160 159 khays
  const unsigned int count = this->count_ + this->irelative_count_;
1161 27 khays
  for (unsigned int i = 0;
1162
       i < count;
1163
       ++i,
1164
         pov += plt_entry_size,
1165
         got_pov += 4,
1166
         plt_offset += plt_entry_size,
1167
         plt_rel_offset += rel_size,
1168
         got_offset += 4)
1169
    {
1170
      // Set and adjust the PLT entry itself.
1171
 
1172
      if (parameters->options().output_is_position_independent())
1173
        {
1174
          memcpy(pov, dyn_plt_entry, plt_entry_size);
1175
          elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1176
        }
1177
      else
1178
        {
1179
          memcpy(pov, exec_plt_entry, plt_entry_size);
1180
          elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1181
                                                      (got_address
1182
                                                       + got_offset));
1183
        }
1184
 
1185
      elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1186
      elfcpp::Swap<32, false>::writeval(pov + 12,
1187
                                        - (plt_offset + plt_entry_size));
1188
 
1189
      // Set the entry in the GOT.
1190
      elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
1191
    }
1192
 
1193
  // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1194
  // the GOT to point to the actual symbol value, rather than point to
1195
  // the PLT entry.  That will let the dynamic linker call the right
1196
  // function when resolving IRELATIVE relocations.
1197 159 khays
  unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1198 27 khays
  for (std::vector<Global_ifunc>::const_iterator p =
1199
         this->global_ifuncs_.begin();
1200
       p != this->global_ifuncs_.end();
1201
       ++p)
1202
    {
1203
      const Sized_symbol<32>* ssym =
1204
        static_cast<const Sized_symbol<32>*>(p->sym);
1205 159 khays
      elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1206 27 khays
                                        ssym->value());
1207
    }
1208
 
1209
  for (std::vector<Local_ifunc>::const_iterator p =
1210
         this->local_ifuncs_.begin();
1211
       p != this->local_ifuncs_.end();
1212
       ++p)
1213
    {
1214
      const Symbol_value<32>* psymval =
1215
        p->object->local_symbol(p->local_sym_index);
1216 159 khays
      elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1217 27 khays
                                        psymval->value(p->object, 0));
1218
    }
1219
 
1220
  gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1221
  gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1222
 
1223
  of->write_output_view(offset, oview_size, oview);
1224
  of->write_output_view(got_file_offset, got_size, got_view);
1225
}
1226
 
1227
// Create the PLT section.
1228
 
1229
void
1230
Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1231
{
1232
  if (this->plt_ == NULL)
1233
    {
1234
      // Create the GOT sections first.
1235
      this->got_section(symtab, layout);
1236
 
1237 159 khays
      this->plt_ = new Output_data_plt_i386(layout, this->got_plt_,
1238
                                            this->got_irelative_);
1239 27 khays
      layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1240
                                      (elfcpp::SHF_ALLOC
1241
                                       | elfcpp::SHF_EXECINSTR),
1242
                                      this->plt_, ORDER_PLT, false);
1243
 
1244
      // Make the sh_info field of .rel.plt point to .plt.
1245
      Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1246
      rel_plt_os->set_info_section(this->plt_->output_section());
1247
    }
1248
}
1249
 
1250
// Create a PLT entry for a global symbol.
1251
 
1252
void
1253
Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1254
{
1255
  if (gsym->has_plt_offset())
1256
    return;
1257
  if (this->plt_ == NULL)
1258
    this->make_plt_section(symtab, layout);
1259 159 khays
  this->plt_->add_entry(symtab, layout, gsym);
1260 27 khays
}
1261
 
1262
// Make a PLT entry for a local STT_GNU_IFUNC symbol.
1263
 
1264
void
1265
Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1266
                                        Sized_relobj_file<32, false>* relobj,
1267
                                        unsigned int local_sym_index)
1268
{
1269
  if (relobj->local_has_plt_offset(local_sym_index))
1270
    return;
1271
  if (this->plt_ == NULL)
1272
    this->make_plt_section(symtab, layout);
1273 159 khays
  unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1274
                                                              relobj,
1275 27 khays
                                                              local_sym_index);
1276
  relobj->set_local_plt_offset(local_sym_index, plt_offset);
1277
}
1278
 
1279
// Return the number of entries in the PLT.
1280
 
1281
unsigned int
1282
Target_i386::plt_entry_count() const
1283
{
1284
  if (this->plt_ == NULL)
1285
    return 0;
1286
  return this->plt_->entry_count();
1287
}
1288
 
1289
// Return the offset of the first non-reserved PLT entry.
1290
 
1291
unsigned int
1292
Target_i386::first_plt_entry_offset() const
1293
{
1294
  return Output_data_plt_i386::first_plt_entry_offset();
1295
}
1296
 
1297
// Return the size of each PLT entry.
1298
 
1299
unsigned int
1300
Target_i386::plt_entry_size() const
1301
{
1302
  return Output_data_plt_i386::get_plt_entry_size();
1303
}
1304
 
1305
// Get the section to use for TLS_DESC relocations.
1306
 
1307
Target_i386::Reloc_section*
1308
Target_i386::rel_tls_desc_section(Layout* layout) const
1309
{
1310
  return this->plt_section()->rel_tls_desc(layout);
1311
}
1312
 
1313
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1314
 
1315
void
1316
Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1317
{
1318
  if (this->tls_base_symbol_defined_)
1319
    return;
1320
 
1321
  Output_segment* tls_segment = layout->tls_segment();
1322
  if (tls_segment != NULL)
1323
    {
1324
      bool is_exec = parameters->options().output_is_executable();
1325
      symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1326
                                       Symbol_table::PREDEFINED,
1327
                                       tls_segment, 0, 0,
1328
                                       elfcpp::STT_TLS,
1329
                                       elfcpp::STB_LOCAL,
1330
                                       elfcpp::STV_HIDDEN, 0,
1331
                                       (is_exec
1332
                                        ? Symbol::SEGMENT_END
1333
                                        : Symbol::SEGMENT_START),
1334
                                       true);
1335
    }
1336
  this->tls_base_symbol_defined_ = true;
1337
}
1338
 
1339
// Create a GOT entry for the TLS module index.
1340
 
1341
unsigned int
1342
Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1343
                                 Sized_relobj_file<32, false>* object)
1344
{
1345
  if (this->got_mod_index_offset_ == -1U)
1346
    {
1347
      gold_assert(symtab != NULL && layout != NULL && object != NULL);
1348
      Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1349
      Output_data_got<32, false>* got = this->got_section(symtab, layout);
1350
      unsigned int got_offset = got->add_constant(0);
1351
      rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1352
                         got_offset);
1353
      got->add_constant(0);
1354
      this->got_mod_index_offset_ = got_offset;
1355
    }
1356
  return this->got_mod_index_offset_;
1357
}
1358
 
1359
// Optimize the TLS relocation type based on what we know about the
1360
// symbol.  IS_FINAL is true if the final address of this symbol is
1361
// known at link time.
1362
 
1363
tls::Tls_optimization
1364
Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1365
{
1366
  // If we are generating a shared library, then we can't do anything
1367
  // in the linker.
1368
  if (parameters->options().shared())
1369
    return tls::TLSOPT_NONE;
1370
 
1371
  switch (r_type)
1372
    {
1373
    case elfcpp::R_386_TLS_GD:
1374
    case elfcpp::R_386_TLS_GOTDESC:
1375
    case elfcpp::R_386_TLS_DESC_CALL:
1376
      // These are General-Dynamic which permits fully general TLS
1377
      // access.  Since we know that we are generating an executable,
1378
      // we can convert this to Initial-Exec.  If we also know that
1379
      // this is a local symbol, we can further switch to Local-Exec.
1380
      if (is_final)
1381
        return tls::TLSOPT_TO_LE;
1382
      return tls::TLSOPT_TO_IE;
1383
 
1384
    case elfcpp::R_386_TLS_LDM:
1385
      // This is Local-Dynamic, which refers to a local symbol in the
1386
      // dynamic TLS block.  Since we know that we generating an
1387
      // executable, we can switch to Local-Exec.
1388
      return tls::TLSOPT_TO_LE;
1389
 
1390
    case elfcpp::R_386_TLS_LDO_32:
1391
      // Another type of Local-Dynamic relocation.
1392
      return tls::TLSOPT_TO_LE;
1393
 
1394
    case elfcpp::R_386_TLS_IE:
1395
    case elfcpp::R_386_TLS_GOTIE:
1396
    case elfcpp::R_386_TLS_IE_32:
1397
      // These are Initial-Exec relocs which get the thread offset
1398
      // from the GOT.  If we know that we are linking against the
1399
      // local symbol, we can switch to Local-Exec, which links the
1400
      // thread offset into the instruction.
1401
      if (is_final)
1402
        return tls::TLSOPT_TO_LE;
1403
      return tls::TLSOPT_NONE;
1404
 
1405
    case elfcpp::R_386_TLS_LE:
1406
    case elfcpp::R_386_TLS_LE_32:
1407
      // When we already have Local-Exec, there is nothing further we
1408
      // can do.
1409
      return tls::TLSOPT_NONE;
1410
 
1411
    default:
1412
      gold_unreachable();
1413
    }
1414
}
1415
 
1416
// Get the Reference_flags for a particular relocation.
1417
 
1418
int
1419
Target_i386::Scan::get_reference_flags(unsigned int r_type)
1420
{
1421
  switch (r_type)
1422
    {
1423
    case elfcpp::R_386_NONE:
1424
    case elfcpp::R_386_GNU_VTINHERIT:
1425
    case elfcpp::R_386_GNU_VTENTRY:
1426
    case elfcpp::R_386_GOTPC:
1427
      // No symbol reference.
1428
      return 0;
1429
 
1430
    case elfcpp::R_386_32:
1431
    case elfcpp::R_386_16:
1432
    case elfcpp::R_386_8:
1433
      return Symbol::ABSOLUTE_REF;
1434
 
1435
    case elfcpp::R_386_PC32:
1436
    case elfcpp::R_386_PC16:
1437
    case elfcpp::R_386_PC8:
1438
    case elfcpp::R_386_GOTOFF:
1439
      return Symbol::RELATIVE_REF;
1440
 
1441
    case elfcpp::R_386_PLT32:
1442
      return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1443
 
1444
    case elfcpp::R_386_GOT32:
1445
      // Absolute in GOT.
1446
      return Symbol::ABSOLUTE_REF;
1447
 
1448
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
1449
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1450
    case elfcpp::R_386_TLS_DESC_CALL:
1451
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1452
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1453
    case elfcpp::R_386_TLS_IE:            // Initial-exec
1454
    case elfcpp::R_386_TLS_IE_32:
1455
    case elfcpp::R_386_TLS_GOTIE:
1456
    case elfcpp::R_386_TLS_LE:            // Local-exec
1457
    case elfcpp::R_386_TLS_LE_32:
1458
      return Symbol::TLS_REF;
1459
 
1460
    case elfcpp::R_386_COPY:
1461
    case elfcpp::R_386_GLOB_DAT:
1462
    case elfcpp::R_386_JUMP_SLOT:
1463
    case elfcpp::R_386_RELATIVE:
1464
    case elfcpp::R_386_IRELATIVE:
1465
    case elfcpp::R_386_TLS_TPOFF:
1466
    case elfcpp::R_386_TLS_DTPMOD32:
1467
    case elfcpp::R_386_TLS_DTPOFF32:
1468
    case elfcpp::R_386_TLS_TPOFF32:
1469
    case elfcpp::R_386_TLS_DESC:
1470
    case elfcpp::R_386_32PLT:
1471
    case elfcpp::R_386_TLS_GD_32:
1472
    case elfcpp::R_386_TLS_GD_PUSH:
1473
    case elfcpp::R_386_TLS_GD_CALL:
1474
    case elfcpp::R_386_TLS_GD_POP:
1475
    case elfcpp::R_386_TLS_LDM_32:
1476
    case elfcpp::R_386_TLS_LDM_PUSH:
1477
    case elfcpp::R_386_TLS_LDM_CALL:
1478
    case elfcpp::R_386_TLS_LDM_POP:
1479
    case elfcpp::R_386_USED_BY_INTEL_200:
1480
    default:
1481
      // Not expected.  We will give an error later.
1482
      return 0;
1483
    }
1484
}
1485
 
1486
// Report an unsupported relocation against a local symbol.
1487
 
1488
void
1489
Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1490
                                           unsigned int r_type)
1491
{
1492
  gold_error(_("%s: unsupported reloc %u against local symbol"),
1493
             object->name().c_str(), r_type);
1494
}
1495
 
1496
// Return whether we need to make a PLT entry for a relocation of a
1497
// given type against a STT_GNU_IFUNC symbol.
1498
 
1499
bool
1500
Target_i386::Scan::reloc_needs_plt_for_ifunc(
1501
    Sized_relobj_file<32, false>* object,
1502
    unsigned int r_type)
1503
{
1504
  int flags = Scan::get_reference_flags(r_type);
1505
  if (flags & Symbol::TLS_REF)
1506
    gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1507
               object->name().c_str(), r_type);
1508
  return flags != 0;
1509
}
1510
 
1511
// Scan a relocation for a local symbol.
1512
 
1513
inline void
1514
Target_i386::Scan::local(Symbol_table* symtab,
1515
                         Layout* layout,
1516
                         Target_i386* target,
1517
                         Sized_relobj_file<32, false>* object,
1518
                         unsigned int data_shndx,
1519
                         Output_section* output_section,
1520
                         const elfcpp::Rel<32, false>& reloc,
1521
                         unsigned int r_type,
1522
                         const elfcpp::Sym<32, false>& lsym)
1523
{
1524
  // A local STT_GNU_IFUNC symbol may require a PLT entry.
1525
  if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1526
      && this->reloc_needs_plt_for_ifunc(object, r_type))
1527
    {
1528
      unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1529
      target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1530
    }
1531
 
1532
  switch (r_type)
1533
    {
1534
    case elfcpp::R_386_NONE:
1535
    case elfcpp::R_386_GNU_VTINHERIT:
1536
    case elfcpp::R_386_GNU_VTENTRY:
1537
      break;
1538
 
1539
    case elfcpp::R_386_32:
1540
      // If building a shared library (or a position-independent
1541
      // executable), we need to create a dynamic relocation for
1542
      // this location. The relocation applied at link time will
1543
      // apply the link-time value, so we flag the location with
1544
      // an R_386_RELATIVE relocation so the dynamic loader can
1545
      // relocate it easily.
1546
      if (parameters->options().output_is_position_independent())
1547
        {
1548
          Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1549
          unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1550
          rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1551
                                      output_section, data_shndx,
1552
                                      reloc.get_r_offset());
1553
        }
1554
      break;
1555
 
1556
    case elfcpp::R_386_16:
1557
    case elfcpp::R_386_8:
1558
      // If building a shared library (or a position-independent
1559
      // executable), we need to create a dynamic relocation for
1560
      // this location. Because the addend needs to remain in the
1561
      // data section, we need to be careful not to apply this
1562
      // relocation statically.
1563
      if (parameters->options().output_is_position_independent())
1564
        {
1565
          Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1566
          unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1567
          if (lsym.get_st_type() != elfcpp::STT_SECTION)
1568
            rel_dyn->add_local(object, r_sym, r_type, output_section,
1569
                               data_shndx, reloc.get_r_offset());
1570
          else
1571
            {
1572
              gold_assert(lsym.get_st_value() == 0);
1573
              unsigned int shndx = lsym.get_st_shndx();
1574
              bool is_ordinary;
1575
              shndx = object->adjust_sym_shndx(r_sym, shndx,
1576
                                               &is_ordinary);
1577
              if (!is_ordinary)
1578
                object->error(_("section symbol %u has bad shndx %u"),
1579
                              r_sym, shndx);
1580
              else
1581
                rel_dyn->add_local_section(object, shndx,
1582
                                           r_type, output_section,
1583
                                           data_shndx, reloc.get_r_offset());
1584
            }
1585
        }
1586
      break;
1587
 
1588
    case elfcpp::R_386_PC32:
1589
    case elfcpp::R_386_PC16:
1590
    case elfcpp::R_386_PC8:
1591
      break;
1592
 
1593
    case elfcpp::R_386_PLT32:
1594
      // Since we know this is a local symbol, we can handle this as a
1595
      // PC32 reloc.
1596
      break;
1597
 
1598
    case elfcpp::R_386_GOTOFF:
1599
    case elfcpp::R_386_GOTPC:
1600
      // We need a GOT section.
1601
      target->got_section(symtab, layout);
1602
      break;
1603
 
1604
    case elfcpp::R_386_GOT32:
1605
      {
1606
        // The symbol requires a GOT entry.
1607
        Output_data_got<32, false>* got = target->got_section(symtab, layout);
1608
        unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1609
 
1610
        // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
1611
        // lets function pointers compare correctly with shared
1612
        // libraries.  Otherwise we would need an IRELATIVE reloc.
1613
        bool is_new;
1614
        if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1615
          is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1616
        else
1617
          is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1618
        if (is_new)
1619
          {
1620
            // If we are generating a shared object, we need to add a
1621
            // dynamic RELATIVE relocation for this symbol's GOT entry.
1622
            if (parameters->options().output_is_position_independent())
1623
              {
1624
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1625
                unsigned int got_offset =
1626
                  object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1627
                rel_dyn->add_local_relative(object, r_sym,
1628
                                            elfcpp::R_386_RELATIVE,
1629
                                            got, got_offset);
1630
              }
1631
          }
1632
      }
1633
      break;
1634
 
1635
      // These are relocations which should only be seen by the
1636
      // dynamic linker, and should never be seen here.
1637
    case elfcpp::R_386_COPY:
1638
    case elfcpp::R_386_GLOB_DAT:
1639
    case elfcpp::R_386_JUMP_SLOT:
1640
    case elfcpp::R_386_RELATIVE:
1641
    case elfcpp::R_386_IRELATIVE:
1642
    case elfcpp::R_386_TLS_TPOFF:
1643
    case elfcpp::R_386_TLS_DTPMOD32:
1644
    case elfcpp::R_386_TLS_DTPOFF32:
1645
    case elfcpp::R_386_TLS_TPOFF32:
1646
    case elfcpp::R_386_TLS_DESC:
1647
      gold_error(_("%s: unexpected reloc %u in object file"),
1648
                 object->name().c_str(), r_type);
1649
      break;
1650
 
1651
      // These are initial TLS relocs, which are expected when
1652
      // linking.
1653
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
1654
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1655
    case elfcpp::R_386_TLS_DESC_CALL:
1656
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1657
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1658
    case elfcpp::R_386_TLS_IE:            // Initial-exec
1659
    case elfcpp::R_386_TLS_IE_32:
1660
    case elfcpp::R_386_TLS_GOTIE:
1661
    case elfcpp::R_386_TLS_LE:            // Local-exec
1662
    case elfcpp::R_386_TLS_LE_32:
1663
      {
1664
        bool output_is_shared = parameters->options().shared();
1665
        const tls::Tls_optimization optimized_type
1666
            = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1667
        switch (r_type)
1668
          {
1669
          case elfcpp::R_386_TLS_GD:          // Global-dynamic
1670
            if (optimized_type == tls::TLSOPT_NONE)
1671
              {
1672
                // Create a pair of GOT entries for the module index and
1673
                // dtv-relative offset.
1674
                Output_data_got<32, false>* got
1675
                    = target->got_section(symtab, layout);
1676
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1677
                unsigned int shndx = lsym.get_st_shndx();
1678
                bool is_ordinary;
1679
                shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1680
                if (!is_ordinary)
1681
                  object->error(_("local symbol %u has bad shndx %u"),
1682
                              r_sym, shndx);
1683
                else
1684
                  got->add_local_pair_with_rel(object, r_sym, shndx,
1685
                                               GOT_TYPE_TLS_PAIR,
1686
                                               target->rel_dyn_section(layout),
1687
                                               elfcpp::R_386_TLS_DTPMOD32, 0);
1688
              }
1689
            else if (optimized_type != tls::TLSOPT_TO_LE)
1690
              unsupported_reloc_local(object, r_type);
1691
            break;
1692
 
1693
          case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1694
            target->define_tls_base_symbol(symtab, layout);
1695
            if (optimized_type == tls::TLSOPT_NONE)
1696
              {
1697
                // Create a double GOT entry with an R_386_TLS_DESC
1698
                // reloc.  The R_386_TLS_DESC reloc is resolved
1699
                // lazily, so the GOT entry needs to be in an area in
1700
                // .got.plt, not .got.  Call got_section to make sure
1701
                // the section has been created.
1702
                target->got_section(symtab, layout);
1703
                Output_data_got<32, false>* got = target->got_tlsdesc_section();
1704
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1705
                if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1706
                  {
1707
                    unsigned int got_offset = got->add_constant(0);
1708
                    // The local symbol value is stored in the second
1709
                    // GOT entry.
1710
                    got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1711
                    // That set the GOT offset of the local symbol to
1712
                    // point to the second entry, but we want it to
1713
                    // point to the first.
1714
                    object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1715
                                                 got_offset);
1716
                    Reloc_section* rt = target->rel_tls_desc_section(layout);
1717
                    rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1718
                  }
1719
              }
1720
            else if (optimized_type != tls::TLSOPT_TO_LE)
1721
              unsupported_reloc_local(object, r_type);
1722
            break;
1723
 
1724
          case elfcpp::R_386_TLS_DESC_CALL:
1725
            break;
1726
 
1727
          case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1728
            if (optimized_type == tls::TLSOPT_NONE)
1729
              {
1730
                // Create a GOT entry for the module index.
1731
                target->got_mod_index_entry(symtab, layout, object);
1732
              }
1733
            else if (optimized_type != tls::TLSOPT_TO_LE)
1734
              unsupported_reloc_local(object, r_type);
1735
            break;
1736
 
1737
          case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1738
            break;
1739
 
1740
          case elfcpp::R_386_TLS_IE:          // Initial-exec
1741
          case elfcpp::R_386_TLS_IE_32:
1742
          case elfcpp::R_386_TLS_GOTIE:
1743
            layout->set_has_static_tls();
1744
            if (optimized_type == tls::TLSOPT_NONE)
1745
              {
1746
                // For the R_386_TLS_IE relocation, we need to create a
1747
                // dynamic relocation when building a shared library.
1748
                if (r_type == elfcpp::R_386_TLS_IE
1749
                    && parameters->options().shared())
1750
                  {
1751
                    Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1752
                    unsigned int r_sym
1753
                        = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1754
                    rel_dyn->add_local_relative(object, r_sym,
1755
                                                elfcpp::R_386_RELATIVE,
1756
                                                output_section, data_shndx,
1757
                                                reloc.get_r_offset());
1758
                  }
1759
                // Create a GOT entry for the tp-relative offset.
1760
                Output_data_got<32, false>* got
1761
                    = target->got_section(symtab, layout);
1762
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1763
                unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1764
                                           ? elfcpp::R_386_TLS_TPOFF32
1765
                                           : elfcpp::R_386_TLS_TPOFF);
1766
                unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1767
                                         ? GOT_TYPE_TLS_OFFSET
1768
                                         : GOT_TYPE_TLS_NOFFSET);
1769
                got->add_local_with_rel(object, r_sym, got_type,
1770
                                        target->rel_dyn_section(layout),
1771
                                        dyn_r_type);
1772
              }
1773
            else if (optimized_type != tls::TLSOPT_TO_LE)
1774
              unsupported_reloc_local(object, r_type);
1775
            break;
1776
 
1777
          case elfcpp::R_386_TLS_LE:          // Local-exec
1778
          case elfcpp::R_386_TLS_LE_32:
1779
            layout->set_has_static_tls();
1780
            if (output_is_shared)
1781
              {
1782
                // We need to create a dynamic relocation.
1783
                gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1784
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1785
                unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1786
                                           ? elfcpp::R_386_TLS_TPOFF32
1787
                                           : elfcpp::R_386_TLS_TPOFF);
1788
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1789
                rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1790
                                   data_shndx, reloc.get_r_offset());
1791
              }
1792
            break;
1793
 
1794
          default:
1795
            gold_unreachable();
1796
          }
1797
      }
1798
      break;
1799
 
1800
    case elfcpp::R_386_32PLT:
1801
    case elfcpp::R_386_TLS_GD_32:
1802
    case elfcpp::R_386_TLS_GD_PUSH:
1803
    case elfcpp::R_386_TLS_GD_CALL:
1804
    case elfcpp::R_386_TLS_GD_POP:
1805
    case elfcpp::R_386_TLS_LDM_32:
1806
    case elfcpp::R_386_TLS_LDM_PUSH:
1807
    case elfcpp::R_386_TLS_LDM_CALL:
1808
    case elfcpp::R_386_TLS_LDM_POP:
1809
    case elfcpp::R_386_USED_BY_INTEL_200:
1810
    default:
1811
      unsupported_reloc_local(object, r_type);
1812
      break;
1813
    }
1814
}
1815
 
1816
// Report an unsupported relocation against a global symbol.
1817
 
1818
void
1819
Target_i386::Scan::unsupported_reloc_global(
1820
    Sized_relobj_file<32, false>* object,
1821
    unsigned int r_type,
1822
    Symbol* gsym)
1823
{
1824
  gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1825
             object->name().c_str(), r_type, gsym->demangled_name().c_str());
1826
}
1827
 
1828
inline bool
1829
Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1830
{
1831
  switch (r_type)
1832
    {
1833
    case elfcpp::R_386_32:
1834
    case elfcpp::R_386_16:
1835
    case elfcpp::R_386_8:
1836
    case elfcpp::R_386_GOTOFF:
1837
    case elfcpp::R_386_GOT32:
1838
      {
1839
        return true;
1840
      }
1841
    default:
1842
      return false;
1843
    }
1844
  return false;
1845
}
1846
 
1847
inline bool
1848
Target_i386::Scan::local_reloc_may_be_function_pointer(
1849
  Symbol_table* ,
1850
  Layout* ,
1851
  Target_i386* ,
1852
  Sized_relobj_file<32, false>* ,
1853
  unsigned int ,
1854
  Output_section* ,
1855
  const elfcpp::Rel<32, false>& ,
1856
  unsigned int r_type,
1857
  const elfcpp::Sym<32, false>&)
1858
{
1859
  return possible_function_pointer_reloc(r_type);
1860
}
1861
 
1862
inline bool
1863
Target_i386::Scan::global_reloc_may_be_function_pointer(
1864
  Symbol_table* ,
1865
  Layout* ,
1866
  Target_i386* ,
1867
  Sized_relobj_file<32, false>* ,
1868
  unsigned int ,
1869
  Output_section* ,
1870
  const elfcpp::Rel<32, false>& ,
1871
  unsigned int r_type,
1872
  Symbol*)
1873
{
1874
  return possible_function_pointer_reloc(r_type);
1875
}
1876
 
1877
// Scan a relocation for a global symbol.
1878
 
1879
inline void
1880
Target_i386::Scan::global(Symbol_table* symtab,
1881
                          Layout* layout,
1882
                          Target_i386* target,
1883
                          Sized_relobj_file<32, false>* object,
1884
                          unsigned int data_shndx,
1885
                          Output_section* output_section,
1886
                          const elfcpp::Rel<32, false>& reloc,
1887
                          unsigned int r_type,
1888
                          Symbol* gsym)
1889
{
1890
  // A STT_GNU_IFUNC symbol may require a PLT entry.
1891
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
1892
      && this->reloc_needs_plt_for_ifunc(object, r_type))
1893
    target->make_plt_entry(symtab, layout, gsym);
1894
 
1895
  switch (r_type)
1896
    {
1897
    case elfcpp::R_386_NONE:
1898
    case elfcpp::R_386_GNU_VTINHERIT:
1899
    case elfcpp::R_386_GNU_VTENTRY:
1900
      break;
1901
 
1902
    case elfcpp::R_386_32:
1903
    case elfcpp::R_386_16:
1904
    case elfcpp::R_386_8:
1905
      {
1906
        // Make a PLT entry if necessary.
1907
        if (gsym->needs_plt_entry())
1908
          {
1909
            target->make_plt_entry(symtab, layout, gsym);
1910
            // Since this is not a PC-relative relocation, we may be
1911
            // taking the address of a function. In that case we need to
1912
            // set the entry in the dynamic symbol table to the address of
1913
            // the PLT entry.
1914
            if (gsym->is_from_dynobj() && !parameters->options().shared())
1915
              gsym->set_needs_dynsym_value();
1916
          }
1917
        // Make a dynamic relocation if necessary.
1918
        if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1919
          {
1920
            if (gsym->may_need_copy_reloc())
1921
              {
1922
                target->copy_reloc(symtab, layout, object,
1923
                                   data_shndx, output_section, gsym, reloc);
1924
              }
1925
            else if (r_type == elfcpp::R_386_32
1926
                     && gsym->type() == elfcpp::STT_GNU_IFUNC
1927
                     && gsym->can_use_relative_reloc(false)
1928
                     && !gsym->is_from_dynobj()
1929
                     && !gsym->is_undefined()
1930
                     && !gsym->is_preemptible())
1931
              {
1932
                // Use an IRELATIVE reloc for a locally defined
1933
                // STT_GNU_IFUNC symbol.  This makes a function
1934
                // address in a PIE executable match the address in a
1935
                // shared library that it links against.
1936 159 khays
                Reloc_section* rel_dyn = target->rel_irelative_section(layout);
1937 27 khays
                rel_dyn->add_symbolless_global_addend(gsym,
1938
                                                      elfcpp::R_386_IRELATIVE,
1939
                                                      output_section,
1940
                                                      object, data_shndx,
1941
                                                      reloc.get_r_offset());
1942
              }
1943
            else if (r_type == elfcpp::R_386_32
1944
                     && gsym->can_use_relative_reloc(false))
1945
              {
1946
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1947
                rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1948
                                             output_section, object,
1949
                                             data_shndx, reloc.get_r_offset());
1950
              }
1951
            else
1952
              {
1953
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1954
                rel_dyn->add_global(gsym, r_type, output_section, object,
1955
                                    data_shndx, reloc.get_r_offset());
1956
              }
1957
          }
1958
      }
1959
      break;
1960
 
1961
    case elfcpp::R_386_PC32:
1962
    case elfcpp::R_386_PC16:
1963
    case elfcpp::R_386_PC8:
1964
      {
1965
        // Make a PLT entry if necessary.
1966
        if (gsym->needs_plt_entry())
1967
          {
1968
            // These relocations are used for function calls only in
1969
            // non-PIC code.  For a 32-bit relocation in a shared library,
1970
            // we'll need a text relocation anyway, so we can skip the
1971
            // PLT entry and let the dynamic linker bind the call directly
1972
            // to the target.  For smaller relocations, we should use a
1973
            // PLT entry to ensure that the call can reach.
1974
            if (!parameters->options().shared()
1975
                || r_type != elfcpp::R_386_PC32)
1976
              target->make_plt_entry(symtab, layout, gsym);
1977
          }
1978
        // Make a dynamic relocation if necessary.
1979
        if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1980
          {
1981
            if (gsym->may_need_copy_reloc())
1982
              {
1983
                target->copy_reloc(symtab, layout, object,
1984
                                   data_shndx, output_section, gsym, reloc);
1985
              }
1986
            else
1987
              {
1988
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1989
                rel_dyn->add_global(gsym, r_type, output_section, object,
1990
                                    data_shndx, reloc.get_r_offset());
1991
              }
1992
          }
1993
      }
1994
      break;
1995
 
1996
    case elfcpp::R_386_GOT32:
1997
      {
1998
        // The symbol requires a GOT entry.
1999
        Output_data_got<32, false>* got = target->got_section(symtab, layout);
2000
        if (gsym->final_value_is_known())
2001
          {
2002
            // For a STT_GNU_IFUNC symbol we want the PLT address.
2003
            if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2004
              got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2005
            else
2006
              got->add_global(gsym, GOT_TYPE_STANDARD);
2007
          }
2008
        else
2009
          {
2010
            // If this symbol is not fully resolved, we need to add a
2011
            // GOT entry with a dynamic relocation.
2012
            Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2013 159 khays
 
2014
            // Use a GLOB_DAT rather than a RELATIVE reloc if:
2015
            //
2016
            // 1) The symbol may be defined in some other module.
2017
            //
2018
            // 2) We are building a shared library and this is a
2019
            // protected symbol; using GLOB_DAT means that the dynamic
2020
            // linker can use the address of the PLT in the main
2021
            // executable when appropriate so that function address
2022
            // comparisons work.
2023
            //
2024
            // 3) This is a STT_GNU_IFUNC symbol in position dependent
2025
            // code, again so that function address comparisons work.
2026 27 khays
            if (gsym->is_from_dynobj()
2027
                || gsym->is_undefined()
2028
                || gsym->is_preemptible()
2029 159 khays
                || (gsym->visibility() == elfcpp::STV_PROTECTED
2030
                    && parameters->options().shared())
2031 27 khays
                || (gsym->type() == elfcpp::STT_GNU_IFUNC
2032
                    && parameters->options().output_is_position_independent()))
2033
              got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2034
                                       rel_dyn, elfcpp::R_386_GLOB_DAT);
2035
            else
2036
              {
2037
                // For a STT_GNU_IFUNC symbol we want to write the PLT
2038
                // offset into the GOT, so that function pointer
2039
                // comparisons work correctly.
2040
                bool is_new;
2041
                if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2042
                  is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2043
                else
2044
                  {
2045
                    is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2046
                    // Tell the dynamic linker to use the PLT address
2047
                    // when resolving relocations.
2048
                    if (gsym->is_from_dynobj()
2049
                        && !parameters->options().shared())
2050
                      gsym->set_needs_dynsym_value();
2051
                  }
2052
                if (is_new)
2053
                  {
2054
                    unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2055
                    rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2056
                                                 got, got_off);
2057
                  }
2058
              }
2059
          }
2060
      }
2061
      break;
2062
 
2063
    case elfcpp::R_386_PLT32:
2064
      // If the symbol is fully resolved, this is just a PC32 reloc.
2065
      // Otherwise we need a PLT entry.
2066
      if (gsym->final_value_is_known())
2067
        break;
2068
      // If building a shared library, we can also skip the PLT entry
2069
      // if the symbol is defined in the output file and is protected
2070
      // or hidden.
2071
      if (gsym->is_defined()
2072
          && !gsym->is_from_dynobj()
2073
          && !gsym->is_preemptible())
2074
        break;
2075
      target->make_plt_entry(symtab, layout, gsym);
2076
      break;
2077
 
2078
    case elfcpp::R_386_GOTOFF:
2079
    case elfcpp::R_386_GOTPC:
2080
      // We need a GOT section.
2081
      target->got_section(symtab, layout);
2082
      break;
2083
 
2084
      // These are relocations which should only be seen by the
2085
      // dynamic linker, and should never be seen here.
2086
    case elfcpp::R_386_COPY:
2087
    case elfcpp::R_386_GLOB_DAT:
2088
    case elfcpp::R_386_JUMP_SLOT:
2089
    case elfcpp::R_386_RELATIVE:
2090
    case elfcpp::R_386_IRELATIVE:
2091
    case elfcpp::R_386_TLS_TPOFF:
2092
    case elfcpp::R_386_TLS_DTPMOD32:
2093
    case elfcpp::R_386_TLS_DTPOFF32:
2094
    case elfcpp::R_386_TLS_TPOFF32:
2095
    case elfcpp::R_386_TLS_DESC:
2096
      gold_error(_("%s: unexpected reloc %u in object file"),
2097
                 object->name().c_str(), r_type);
2098
      break;
2099
 
2100
      // These are initial tls relocs, which are expected when
2101
      // linking.
2102
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
2103
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2104
    case elfcpp::R_386_TLS_DESC_CALL:
2105
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2106
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2107
    case elfcpp::R_386_TLS_IE:            // Initial-exec
2108
    case elfcpp::R_386_TLS_IE_32:
2109
    case elfcpp::R_386_TLS_GOTIE:
2110
    case elfcpp::R_386_TLS_LE:            // Local-exec
2111
    case elfcpp::R_386_TLS_LE_32:
2112
      {
2113
        const bool is_final = gsym->final_value_is_known();
2114
        const tls::Tls_optimization optimized_type
2115
            = Target_i386::optimize_tls_reloc(is_final, r_type);
2116
        switch (r_type)
2117
          {
2118
          case elfcpp::R_386_TLS_GD:          // Global-dynamic
2119
            if (optimized_type == tls::TLSOPT_NONE)
2120
              {
2121
                // Create a pair of GOT entries for the module index and
2122
                // dtv-relative offset.
2123
                Output_data_got<32, false>* got
2124
                    = target->got_section(symtab, layout);
2125
                got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2126
                                             target->rel_dyn_section(layout),
2127
                                             elfcpp::R_386_TLS_DTPMOD32,
2128
                                             elfcpp::R_386_TLS_DTPOFF32);
2129
              }
2130
            else if (optimized_type == tls::TLSOPT_TO_IE)
2131
              {
2132
                // Create a GOT entry for the tp-relative offset.
2133
                Output_data_got<32, false>* got
2134
                    = target->got_section(symtab, layout);
2135
                got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2136
                                         target->rel_dyn_section(layout),
2137
                                         elfcpp::R_386_TLS_TPOFF);
2138
              }
2139
            else if (optimized_type != tls::TLSOPT_TO_LE)
2140
              unsupported_reloc_global(object, r_type, gsym);
2141
            break;
2142
 
2143
          case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
2144
            target->define_tls_base_symbol(symtab, layout);
2145
            if (optimized_type == tls::TLSOPT_NONE)
2146
              {
2147
                // Create a double GOT entry with an R_386_TLS_DESC
2148
                // reloc.  The R_386_TLS_DESC reloc is resolved
2149
                // lazily, so the GOT entry needs to be in an area in
2150
                // .got.plt, not .got.  Call got_section to make sure
2151
                // the section has been created.
2152
                target->got_section(symtab, layout);
2153
                Output_data_got<32, false>* got = target->got_tlsdesc_section();
2154
                Reloc_section* rt = target->rel_tls_desc_section(layout);
2155
                got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2156
                                             elfcpp::R_386_TLS_DESC, 0);
2157
              }
2158
            else if (optimized_type == tls::TLSOPT_TO_IE)
2159
              {
2160
                // Create a GOT entry for the tp-relative offset.
2161
                Output_data_got<32, false>* got
2162
                    = target->got_section(symtab, layout);
2163
                got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2164
                                         target->rel_dyn_section(layout),
2165
                                         elfcpp::R_386_TLS_TPOFF);
2166
              }
2167
            else if (optimized_type != tls::TLSOPT_TO_LE)
2168
              unsupported_reloc_global(object, r_type, gsym);
2169
            break;
2170
 
2171
          case elfcpp::R_386_TLS_DESC_CALL:
2172
            break;
2173
 
2174
          case elfcpp::R_386_TLS_LDM:         // Local-dynamic
2175
            if (optimized_type == tls::TLSOPT_NONE)
2176
              {
2177
                // Create a GOT entry for the module index.
2178
                target->got_mod_index_entry(symtab, layout, object);
2179
              }
2180
            else if (optimized_type != tls::TLSOPT_TO_LE)
2181
              unsupported_reloc_global(object, r_type, gsym);
2182
            break;
2183
 
2184
          case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
2185
            break;
2186
 
2187
          case elfcpp::R_386_TLS_IE:          // Initial-exec
2188
          case elfcpp::R_386_TLS_IE_32:
2189
          case elfcpp::R_386_TLS_GOTIE:
2190
            layout->set_has_static_tls();
2191
            if (optimized_type == tls::TLSOPT_NONE)
2192
              {
2193
                // For the R_386_TLS_IE relocation, we need to create a
2194
                // dynamic relocation when building a shared library.
2195
                if (r_type == elfcpp::R_386_TLS_IE
2196
                    && parameters->options().shared())
2197
                  {
2198
                    Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2199
                    rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2200
                                                 output_section, object,
2201
                                                 data_shndx,
2202
                                                 reloc.get_r_offset());
2203
                  }
2204
                // Create a GOT entry for the tp-relative offset.
2205
                Output_data_got<32, false>* got
2206
                    = target->got_section(symtab, layout);
2207
                unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2208
                                           ? elfcpp::R_386_TLS_TPOFF32
2209
                                           : elfcpp::R_386_TLS_TPOFF);
2210
                unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2211
                                         ? GOT_TYPE_TLS_OFFSET
2212
                                         : GOT_TYPE_TLS_NOFFSET);
2213
                got->add_global_with_rel(gsym, got_type,
2214
                                         target->rel_dyn_section(layout),
2215
                                         dyn_r_type);
2216
              }
2217
            else if (optimized_type != tls::TLSOPT_TO_LE)
2218
              unsupported_reloc_global(object, r_type, gsym);
2219
            break;
2220
 
2221
          case elfcpp::R_386_TLS_LE:          // Local-exec
2222
          case elfcpp::R_386_TLS_LE_32:
2223
            layout->set_has_static_tls();
2224
            if (parameters->options().shared())
2225
              {
2226
                // We need to create a dynamic relocation.
2227
                unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2228
                                           ? elfcpp::R_386_TLS_TPOFF32
2229
                                           : elfcpp::R_386_TLS_TPOFF);
2230
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2231
                rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2232
                                    data_shndx, reloc.get_r_offset());
2233
              }
2234
            break;
2235
 
2236
          default:
2237
            gold_unreachable();
2238
          }
2239
      }
2240
      break;
2241
 
2242
    case elfcpp::R_386_32PLT:
2243
    case elfcpp::R_386_TLS_GD_32:
2244
    case elfcpp::R_386_TLS_GD_PUSH:
2245
    case elfcpp::R_386_TLS_GD_CALL:
2246
    case elfcpp::R_386_TLS_GD_POP:
2247
    case elfcpp::R_386_TLS_LDM_32:
2248
    case elfcpp::R_386_TLS_LDM_PUSH:
2249
    case elfcpp::R_386_TLS_LDM_CALL:
2250
    case elfcpp::R_386_TLS_LDM_POP:
2251
    case elfcpp::R_386_USED_BY_INTEL_200:
2252
    default:
2253
      unsupported_reloc_global(object, r_type, gsym);
2254
      break;
2255
    }
2256
}
2257
 
2258
// Process relocations for gc.
2259
 
2260
void
2261
Target_i386::gc_process_relocs(Symbol_table* symtab,
2262
                               Layout* layout,
2263
                               Sized_relobj_file<32, false>* object,
2264
                               unsigned int data_shndx,
2265
                               unsigned int,
2266
                               const unsigned char* prelocs,
2267
                               size_t reloc_count,
2268
                               Output_section* output_section,
2269
                               bool needs_special_offset_handling,
2270
                               size_t local_symbol_count,
2271
                               const unsigned char* plocal_symbols)
2272
{
2273
  gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2274
                          Target_i386::Scan,
2275
                          Target_i386::Relocatable_size_for_reloc>(
2276
    symtab,
2277
    layout,
2278
    this,
2279
    object,
2280
    data_shndx,
2281
    prelocs,
2282
    reloc_count,
2283
    output_section,
2284
    needs_special_offset_handling,
2285
    local_symbol_count,
2286
    plocal_symbols);
2287
}
2288
 
2289
// Scan relocations for a section.
2290
 
2291
void
2292
Target_i386::scan_relocs(Symbol_table* symtab,
2293
                         Layout* layout,
2294
                         Sized_relobj_file<32, false>* object,
2295
                         unsigned int data_shndx,
2296
                         unsigned int sh_type,
2297
                         const unsigned char* prelocs,
2298
                         size_t reloc_count,
2299
                         Output_section* output_section,
2300
                         bool needs_special_offset_handling,
2301
                         size_t local_symbol_count,
2302
                         const unsigned char* plocal_symbols)
2303
{
2304
  if (sh_type == elfcpp::SHT_RELA)
2305
    {
2306
      gold_error(_("%s: unsupported RELA reloc section"),
2307
                 object->name().c_str());
2308
      return;
2309
    }
2310
 
2311
  gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2312
                    Target_i386::Scan>(
2313
    symtab,
2314
    layout,
2315
    this,
2316
    object,
2317
    data_shndx,
2318
    prelocs,
2319
    reloc_count,
2320
    output_section,
2321
    needs_special_offset_handling,
2322
    local_symbol_count,
2323
    plocal_symbols);
2324
}
2325
 
2326
// Finalize the sections.
2327
 
2328
void
2329
Target_i386::do_finalize_sections(
2330
    Layout* layout,
2331
    const Input_objects*,
2332
    Symbol_table* symtab)
2333
{
2334
  const Reloc_section* rel_plt = (this->plt_ == NULL
2335
                                  ? NULL
2336
                                  : this->plt_->rel_plt());
2337
  layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2338
                                  this->rel_dyn_, true, false);
2339
 
2340
  // Emit any relocs we saved in an attempt to avoid generating COPY
2341
  // relocs.
2342
  if (this->copy_relocs_.any_saved_relocs())
2343
    this->copy_relocs_.emit(this->rel_dyn_section(layout));
2344
 
2345
  // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2346
  // the .got.plt section.
2347
  Symbol* sym = this->global_offset_table_;
2348
  if (sym != NULL)
2349
    {
2350
      uint32_t data_size = this->got_plt_->current_data_size();
2351
      symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2352
    }
2353 159 khays
 
2354
  if (parameters->doing_static_link()
2355
      && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2356
    {
2357
      // If linking statically, make sure that the __rel_iplt symbols
2358
      // were defined if necessary, even if we didn't create a PLT.
2359
      static const Define_symbol_in_segment syms[] =
2360
        {
2361
          {
2362
            "__rel_iplt_start",         // name
2363
            elfcpp::PT_LOAD,            // segment_type
2364
            elfcpp::PF_W,               // segment_flags_set
2365
            elfcpp::PF(0),               // segment_flags_clear
2366
            0,                           // value
2367
            0,                           // size
2368
            elfcpp::STT_NOTYPE,         // type
2369
            elfcpp::STB_GLOBAL,         // binding
2370
            elfcpp::STV_HIDDEN,         // visibility
2371
            0,                           // nonvis
2372
            Symbol::SEGMENT_START,      // offset_from_base
2373
            true                        // only_if_ref
2374
          },
2375
          {
2376
            "__rel_iplt_end",           // name
2377
            elfcpp::PT_LOAD,            // segment_type
2378
            elfcpp::PF_W,               // segment_flags_set
2379
            elfcpp::PF(0),               // segment_flags_clear
2380
            0,                           // value
2381
            0,                           // size
2382
            elfcpp::STT_NOTYPE,         // type
2383
            elfcpp::STB_GLOBAL,         // binding
2384
            elfcpp::STV_HIDDEN,         // visibility
2385
            0,                           // nonvis
2386
            Symbol::SEGMENT_START,      // offset_from_base
2387
            true                        // only_if_ref
2388
          }
2389
        };
2390
 
2391
      symtab->define_symbols(layout, 2, syms,
2392
                             layout->script_options()->saw_sections_clause());
2393
    }
2394 27 khays
}
2395
 
2396
// Return whether a direct absolute static relocation needs to be applied.
2397
// In cases where Scan::local() or Scan::global() has created
2398
// a dynamic relocation other than R_386_RELATIVE, the addend
2399
// of the relocation is carried in the data, and we must not
2400
// apply the static relocation.
2401
 
2402
inline bool
2403
Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2404
                                                 unsigned int r_type,
2405
                                                 bool is_32bit,
2406
                                                 Output_section* output_section)
2407
{
2408
  // If the output section is not allocated, then we didn't call
2409
  // scan_relocs, we didn't create a dynamic reloc, and we must apply
2410
  // the reloc here.
2411
  if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2412
    return true;
2413
 
2414
  int ref_flags = Scan::get_reference_flags(r_type);
2415
 
2416
  // For local symbols, we will have created a non-RELATIVE dynamic
2417
  // relocation only if (a) the output is position independent,
2418
  // (b) the relocation is absolute (not pc- or segment-relative), and
2419
  // (c) the relocation is not 32 bits wide.
2420
  if (gsym == NULL)
2421
    return !(parameters->options().output_is_position_independent()
2422
             && (ref_flags & Symbol::ABSOLUTE_REF)
2423
             && !is_32bit);
2424
 
2425
  // For global symbols, we use the same helper routines used in the
2426
  // scan pass.  If we did not create a dynamic relocation, or if we
2427
  // created a RELATIVE dynamic relocation, we should apply the static
2428
  // relocation.
2429
  bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2430
  bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2431
                && gsym->can_use_relative_reloc(ref_flags
2432
                                                & Symbol::FUNCTION_CALL);
2433
  return !has_dyn || is_rel;
2434
}
2435
 
2436
// Perform a relocation.
2437
 
2438
inline bool
2439
Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2440
                                Target_i386* target,
2441
                                Output_section* output_section,
2442
                                size_t relnum,
2443
                                const elfcpp::Rel<32, false>& rel,
2444
                                unsigned int r_type,
2445
                                const Sized_symbol<32>* gsym,
2446
                                const Symbol_value<32>* psymval,
2447
                                unsigned char* view,
2448
                                elfcpp::Elf_types<32>::Elf_Addr address,
2449
                                section_size_type view_size)
2450
{
2451
  if (this->skip_call_tls_get_addr_)
2452
    {
2453
      if ((r_type != elfcpp::R_386_PLT32
2454
           && r_type != elfcpp::R_386_PC32)
2455
          || gsym == NULL
2456
          || strcmp(gsym->name(), "___tls_get_addr") != 0)
2457
        gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2458
                               _("missing expected TLS relocation"));
2459
      else
2460
        {
2461
          this->skip_call_tls_get_addr_ = false;
2462
          return false;
2463
        }
2464
    }
2465
 
2466
  const Sized_relobj_file<32, false>* object = relinfo->object;
2467
 
2468
  // Pick the value to use for symbols defined in shared objects.
2469
  Symbol_value<32> symval;
2470
  if (gsym != NULL
2471
      && gsym->type() == elfcpp::STT_GNU_IFUNC
2472
      && r_type == elfcpp::R_386_32
2473
      && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2474
      && gsym->can_use_relative_reloc(false)
2475
      && !gsym->is_from_dynobj()
2476
      && !gsym->is_undefined()
2477
      && !gsym->is_preemptible())
2478
    {
2479
      // In this case we are generating a R_386_IRELATIVE reloc.  We
2480
      // want to use the real value of the symbol, not the PLT offset.
2481
    }
2482
  else if (gsym != NULL
2483
           && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2484
    {
2485 159 khays
      symval.set_output_value(target->plt_address_for_global(gsym)
2486 27 khays
                              + gsym->plt_offset());
2487
      psymval = &symval;
2488
    }
2489
  else if (gsym == NULL && psymval->is_ifunc_symbol())
2490
    {
2491
      unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2492
      if (object->local_has_plt_offset(r_sym))
2493
        {
2494 159 khays
          symval.set_output_value(target->plt_address_for_local(object, r_sym)
2495 27 khays
                                  + object->local_plt_offset(r_sym));
2496
          psymval = &symval;
2497
        }
2498
    }
2499
 
2500
  // Get the GOT offset if needed.
2501
  // The GOT pointer points to the end of the GOT section.
2502
  // We need to subtract the size of the GOT section to get
2503
  // the actual offset to use in the relocation.
2504
  bool have_got_offset = false;
2505
  unsigned int got_offset = 0;
2506
  switch (r_type)
2507
    {
2508
    case elfcpp::R_386_GOT32:
2509
      if (gsym != NULL)
2510
        {
2511
          gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2512
          got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2513
                        - target->got_size());
2514
        }
2515
      else
2516
        {
2517
          unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2518
          gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2519
          got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2520
                        - target->got_size());
2521
        }
2522
      have_got_offset = true;
2523
      break;
2524
 
2525
    default:
2526
      break;
2527
    }
2528
 
2529
  switch (r_type)
2530
    {
2531
    case elfcpp::R_386_NONE:
2532
    case elfcpp::R_386_GNU_VTINHERIT:
2533
    case elfcpp::R_386_GNU_VTENTRY:
2534
      break;
2535
 
2536
    case elfcpp::R_386_32:
2537
      if (should_apply_static_reloc(gsym, r_type, true, output_section))
2538
        Relocate_functions<32, false>::rel32(view, object, psymval);
2539
      break;
2540
 
2541
    case elfcpp::R_386_PC32:
2542
      if (should_apply_static_reloc(gsym, r_type, true, output_section))
2543
        Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2544
      break;
2545
 
2546
    case elfcpp::R_386_16:
2547
      if (should_apply_static_reloc(gsym, r_type, false, output_section))
2548
        Relocate_functions<32, false>::rel16(view, object, psymval);
2549
      break;
2550
 
2551
    case elfcpp::R_386_PC16:
2552
      if (should_apply_static_reloc(gsym, r_type, false, output_section))
2553
        Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2554
      break;
2555
 
2556
    case elfcpp::R_386_8:
2557
      if (should_apply_static_reloc(gsym, r_type, false, output_section))
2558
        Relocate_functions<32, false>::rel8(view, object, psymval);
2559
      break;
2560
 
2561
    case elfcpp::R_386_PC8:
2562
      if (should_apply_static_reloc(gsym, r_type, false, output_section))
2563
        Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2564
      break;
2565
 
2566
    case elfcpp::R_386_PLT32:
2567
      gold_assert(gsym == NULL
2568
                  || gsym->has_plt_offset()
2569
                  || gsym->final_value_is_known()
2570
                  || (gsym->is_defined()
2571
                      && !gsym->is_from_dynobj()
2572
                      && !gsym->is_preemptible()));
2573
      Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2574
      break;
2575
 
2576
    case elfcpp::R_386_GOT32:
2577
      gold_assert(have_got_offset);
2578
      Relocate_functions<32, false>::rel32(view, got_offset);
2579
      break;
2580
 
2581
    case elfcpp::R_386_GOTOFF:
2582
      {
2583
        elfcpp::Elf_types<32>::Elf_Addr value;
2584
        value = (psymval->value(object, 0)
2585
                 - target->got_plt_section()->address());
2586
        Relocate_functions<32, false>::rel32(view, value);
2587
      }
2588
      break;
2589
 
2590
    case elfcpp::R_386_GOTPC:
2591
      {
2592
        elfcpp::Elf_types<32>::Elf_Addr value;
2593
        value = target->got_plt_section()->address();
2594
        Relocate_functions<32, false>::pcrel32(view, value, address);
2595
      }
2596
      break;
2597
 
2598
    case elfcpp::R_386_COPY:
2599
    case elfcpp::R_386_GLOB_DAT:
2600
    case elfcpp::R_386_JUMP_SLOT:
2601
    case elfcpp::R_386_RELATIVE:
2602
    case elfcpp::R_386_IRELATIVE:
2603
      // These are outstanding tls relocs, which are unexpected when
2604
      // linking.
2605
    case elfcpp::R_386_TLS_TPOFF:
2606
    case elfcpp::R_386_TLS_DTPMOD32:
2607
    case elfcpp::R_386_TLS_DTPOFF32:
2608
    case elfcpp::R_386_TLS_TPOFF32:
2609
    case elfcpp::R_386_TLS_DESC:
2610
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2611
                             _("unexpected reloc %u in object file"),
2612
                             r_type);
2613
      break;
2614
 
2615
      // These are initial tls relocs, which are expected when
2616
      // linking.
2617
    case elfcpp::R_386_TLS_GD:             // Global-dynamic
2618
    case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
2619
    case elfcpp::R_386_TLS_DESC_CALL:
2620
    case elfcpp::R_386_TLS_LDM:            // Local-dynamic
2621
    case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
2622
    case elfcpp::R_386_TLS_IE:             // Initial-exec
2623
    case elfcpp::R_386_TLS_IE_32:
2624
    case elfcpp::R_386_TLS_GOTIE:
2625
    case elfcpp::R_386_TLS_LE:             // Local-exec
2626
    case elfcpp::R_386_TLS_LE_32:
2627
      this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2628
                         view, address, view_size);
2629
      break;
2630
 
2631
    case elfcpp::R_386_32PLT:
2632
    case elfcpp::R_386_TLS_GD_32:
2633
    case elfcpp::R_386_TLS_GD_PUSH:
2634
    case elfcpp::R_386_TLS_GD_CALL:
2635
    case elfcpp::R_386_TLS_GD_POP:
2636
    case elfcpp::R_386_TLS_LDM_32:
2637
    case elfcpp::R_386_TLS_LDM_PUSH:
2638
    case elfcpp::R_386_TLS_LDM_CALL:
2639
    case elfcpp::R_386_TLS_LDM_POP:
2640
    case elfcpp::R_386_USED_BY_INTEL_200:
2641
    default:
2642
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2643
                             _("unsupported reloc %u"),
2644
                             r_type);
2645
      break;
2646
    }
2647
 
2648
  return true;
2649
}
2650
 
2651
// Perform a TLS relocation.
2652
 
2653
inline void
2654
Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2655
                                    Target_i386* target,
2656
                                    size_t relnum,
2657
                                    const elfcpp::Rel<32, false>& rel,
2658
                                    unsigned int r_type,
2659
                                    const Sized_symbol<32>* gsym,
2660
                                    const Symbol_value<32>* psymval,
2661
                                    unsigned char* view,
2662
                                    elfcpp::Elf_types<32>::Elf_Addr,
2663
                                    section_size_type view_size)
2664
{
2665
  Output_segment* tls_segment = relinfo->layout->tls_segment();
2666
 
2667
  const Sized_relobj_file<32, false>* object = relinfo->object;
2668
 
2669
  elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2670
 
2671
  const bool is_final = (gsym == NULL
2672
                         ? !parameters->options().shared()
2673
                         : gsym->final_value_is_known());
2674
  const tls::Tls_optimization optimized_type
2675
      = Target_i386::optimize_tls_reloc(is_final, r_type);
2676
  switch (r_type)
2677
    {
2678
    case elfcpp::R_386_TLS_GD:           // Global-dynamic
2679
      if (optimized_type == tls::TLSOPT_TO_LE)
2680
        {
2681 159 khays
          if (tls_segment == NULL)
2682
            {
2683
              gold_assert(parameters->errors()->error_count() > 0
2684
                          || issue_undefined_symbol_error(gsym));
2685
              return;
2686
            }
2687 27 khays
          this->tls_gd_to_le(relinfo, relnum, tls_segment,
2688
                             rel, r_type, value, view,
2689
                             view_size);
2690
          break;
2691
        }
2692
      else
2693
        {
2694
          unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2695
                                   ? GOT_TYPE_TLS_NOFFSET
2696
                                   : GOT_TYPE_TLS_PAIR);
2697
          unsigned int got_offset;
2698
          if (gsym != NULL)
2699
            {
2700
              gold_assert(gsym->has_got_offset(got_type));
2701
              got_offset = gsym->got_offset(got_type) - target->got_size();
2702
            }
2703
          else
2704
            {
2705
              unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2706
              gold_assert(object->local_has_got_offset(r_sym, got_type));
2707
              got_offset = (object->local_got_offset(r_sym, got_type)
2708
                            - target->got_size());
2709
            }
2710
          if (optimized_type == tls::TLSOPT_TO_IE)
2711
            {
2712 159 khays
              if (tls_segment == NULL)
2713
                {
2714
                  gold_assert(parameters->errors()->error_count() > 0
2715
                              || issue_undefined_symbol_error(gsym));
2716
                  return;
2717
                }
2718 27 khays
              this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2719
                                 got_offset, view, view_size);
2720
              break;
2721
            }
2722
          else if (optimized_type == tls::TLSOPT_NONE)
2723
            {
2724
              // Relocate the field with the offset of the pair of GOT
2725
              // entries.
2726
              Relocate_functions<32, false>::rel32(view, got_offset);
2727
              break;
2728
            }
2729
        }
2730
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2731
                             _("unsupported reloc %u"),
2732
                             r_type);
2733
      break;
2734
 
2735
    case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2736
    case elfcpp::R_386_TLS_DESC_CALL:
2737
      this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2738
      if (optimized_type == tls::TLSOPT_TO_LE)
2739
        {
2740 159 khays
          if (tls_segment == NULL)
2741
            {
2742
              gold_assert(parameters->errors()->error_count() > 0
2743
                          || issue_undefined_symbol_error(gsym));
2744
              return;
2745
            }
2746 27 khays
          this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2747
                                  rel, r_type, value, view,
2748
                                  view_size);
2749
          break;
2750
        }
2751
      else
2752
        {
2753
          unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2754
                                   ? GOT_TYPE_TLS_NOFFSET
2755
                                   : GOT_TYPE_TLS_DESC);
2756
          unsigned int got_offset = 0;
2757
          if (r_type == elfcpp::R_386_TLS_GOTDESC
2758
              && optimized_type == tls::TLSOPT_NONE)
2759
            {
2760
              // We created GOT entries in the .got.tlsdesc portion of
2761
              // the .got.plt section, but the offset stored in the
2762
              // symbol is the offset within .got.tlsdesc.
2763
              got_offset = (target->got_size()
2764
                            + target->got_plt_section()->data_size());
2765
            }
2766
          if (gsym != NULL)
2767
            {
2768
              gold_assert(gsym->has_got_offset(got_type));
2769
              got_offset += gsym->got_offset(got_type) - target->got_size();
2770
            }
2771
          else
2772
            {
2773
              unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2774
              gold_assert(object->local_has_got_offset(r_sym, got_type));
2775
              got_offset += (object->local_got_offset(r_sym, got_type)
2776
                             - target->got_size());
2777
            }
2778
          if (optimized_type == tls::TLSOPT_TO_IE)
2779
            {
2780 159 khays
              if (tls_segment == NULL)
2781
                {
2782
                  gold_assert(parameters->errors()->error_count() > 0
2783
                              || issue_undefined_symbol_error(gsym));
2784
                  return;
2785
                }
2786 27 khays
              this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2787
                                      got_offset, view, view_size);
2788
              break;
2789
            }
2790
          else if (optimized_type == tls::TLSOPT_NONE)
2791
            {
2792
              if (r_type == elfcpp::R_386_TLS_GOTDESC)
2793
                {
2794
                  // Relocate the field with the offset of the pair of GOT
2795
                  // entries.
2796
                  Relocate_functions<32, false>::rel32(view, got_offset);
2797
                }
2798
              break;
2799
            }
2800
        }
2801
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2802
                             _("unsupported reloc %u"),
2803
                             r_type);
2804
      break;
2805
 
2806
    case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2807
      if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2808
        {
2809
          gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2810
                                 _("both SUN and GNU model "
2811
                                   "TLS relocations"));
2812
          break;
2813
        }
2814
      this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2815
      if (optimized_type == tls::TLSOPT_TO_LE)
2816
        {
2817 159 khays
          if (tls_segment == NULL)
2818
            {
2819
              gold_assert(parameters->errors()->error_count() > 0
2820
                          || issue_undefined_symbol_error(gsym));
2821
              return;
2822
            }
2823 27 khays
          this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2824
                             value, view, view_size);
2825
          break;
2826
        }
2827
      else if (optimized_type == tls::TLSOPT_NONE)
2828
        {
2829
          // Relocate the field with the offset of the GOT entry for
2830
          // the module index.
2831
          unsigned int got_offset;
2832
          got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2833
                        - target->got_size());
2834
          Relocate_functions<32, false>::rel32(view, got_offset);
2835
          break;
2836
        }
2837
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2838
                             _("unsupported reloc %u"),
2839
                             r_type);
2840
      break;
2841
 
2842
    case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2843
      if (optimized_type == tls::TLSOPT_TO_LE)
2844
        {
2845
          // This reloc can appear in debugging sections, in which
2846
          // case we must not convert to local-exec.  We decide what
2847
          // to do based on whether the section is marked as
2848
          // containing executable code.  That is what the GNU linker
2849
          // does as well.
2850
          elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2851
          if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2852
            {
2853 159 khays
              if (tls_segment == NULL)
2854
                {
2855
                  gold_assert(parameters->errors()->error_count() > 0
2856
                              || issue_undefined_symbol_error(gsym));
2857
                  return;
2858
                }
2859 27 khays
              value -= tls_segment->memsz();
2860
            }
2861
        }
2862
      Relocate_functions<32, false>::rel32(view, value);
2863
      break;
2864
 
2865
    case elfcpp::R_386_TLS_IE:           // Initial-exec
2866
    case elfcpp::R_386_TLS_GOTIE:
2867
    case elfcpp::R_386_TLS_IE_32:
2868
      if (optimized_type == tls::TLSOPT_TO_LE)
2869
        {
2870 159 khays
          if (tls_segment == NULL)
2871
            {
2872
              gold_assert(parameters->errors()->error_count() > 0
2873
                          || issue_undefined_symbol_error(gsym));
2874
              return;
2875
            }
2876 27 khays
          Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2877
                                              rel, r_type, value, view,
2878
                                              view_size);
2879
          break;
2880
        }
2881
      else if (optimized_type == tls::TLSOPT_NONE)
2882
        {
2883
          // Relocate the field with the offset of the GOT entry for
2884
          // the tp-relative offset of the symbol.
2885
          unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2886
                                   ? GOT_TYPE_TLS_OFFSET
2887
                                   : GOT_TYPE_TLS_NOFFSET);
2888
          unsigned int got_offset;
2889
          if (gsym != NULL)
2890
            {
2891
              gold_assert(gsym->has_got_offset(got_type));
2892
              got_offset = gsym->got_offset(got_type);
2893
            }
2894
          else
2895
            {
2896
              unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2897
              gold_assert(object->local_has_got_offset(r_sym, got_type));
2898
              got_offset = object->local_got_offset(r_sym, got_type);
2899
            }
2900
          // For the R_386_TLS_IE relocation, we need to apply the
2901
          // absolute address of the GOT entry.
2902
          if (r_type == elfcpp::R_386_TLS_IE)
2903
            got_offset += target->got_plt_section()->address();
2904
          // All GOT offsets are relative to the end of the GOT.
2905
          got_offset -= target->got_size();
2906
          Relocate_functions<32, false>::rel32(view, got_offset);
2907
          break;
2908
        }
2909
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2910
                             _("unsupported reloc %u"),
2911
                             r_type);
2912
      break;
2913
 
2914
    case elfcpp::R_386_TLS_LE:           // Local-exec
2915
      // If we're creating a shared library, a dynamic relocation will
2916
      // have been created for this location, so do not apply it now.
2917
      if (!parameters->options().shared())
2918
        {
2919 159 khays
          if (tls_segment == NULL)
2920
            {
2921
              gold_assert(parameters->errors()->error_count() > 0
2922
                          || issue_undefined_symbol_error(gsym));
2923
              return;
2924
            }
2925 27 khays
          value -= tls_segment->memsz();
2926
          Relocate_functions<32, false>::rel32(view, value);
2927
        }
2928
      break;
2929
 
2930
    case elfcpp::R_386_TLS_LE_32:
2931
      // If we're creating a shared library, a dynamic relocation will
2932
      // have been created for this location, so do not apply it now.
2933
      if (!parameters->options().shared())
2934
        {
2935 159 khays
          if (tls_segment == NULL)
2936
            {
2937
              gold_assert(parameters->errors()->error_count() > 0
2938
                          || issue_undefined_symbol_error(gsym));
2939
              return;
2940
            }
2941 27 khays
          value = tls_segment->memsz() - value;
2942
          Relocate_functions<32, false>::rel32(view, value);
2943
        }
2944
      break;
2945
    }
2946
}
2947
 
2948
// Do a relocation in which we convert a TLS General-Dynamic to a
2949
// Local-Exec.
2950
 
2951
inline void
2952
Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2953
                                    size_t relnum,
2954
                                    Output_segment* tls_segment,
2955
                                    const elfcpp::Rel<32, false>& rel,
2956
                                    unsigned int,
2957
                                    elfcpp::Elf_types<32>::Elf_Addr value,
2958
                                    unsigned char* view,
2959
                                    section_size_type view_size)
2960
{
2961
  // leal foo(,%reg,1),%eax; call ___tls_get_addr
2962
  //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2963
  // leal foo(%reg),%eax; call ___tls_get_addr
2964
  //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2965
 
2966
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2967
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2968
 
2969
  unsigned char op1 = view[-1];
2970
  unsigned char op2 = view[-2];
2971
 
2972
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2973
                 op2 == 0x8d || op2 == 0x04);
2974
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2975
 
2976
  int roff = 5;
2977
 
2978
  if (op2 == 0x04)
2979
    {
2980
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2981
      tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2982
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2983
                     ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2984
      memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2985
    }
2986
  else
2987
    {
2988
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2989
                     (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2990
      if (rel.get_r_offset() + 9 < view_size
2991
          && view[9] == 0x90)
2992
        {
2993
          // There is a trailing nop.  Use the size byte subl.
2994
          memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2995
          roff = 6;
2996
        }
2997
      else
2998
        {
2999
          // Use the five byte subl.
3000
          memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3001
        }
3002
    }
3003
 
3004
  value = tls_segment->memsz() - value;
3005
  Relocate_functions<32, false>::rel32(view + roff, value);
3006
 
3007
  // The next reloc should be a PLT32 reloc against __tls_get_addr.
3008
  // We can skip it.
3009
  this->skip_call_tls_get_addr_ = true;
3010
}
3011
 
3012
// Do a relocation in which we convert a TLS General-Dynamic to an
3013
// Initial-Exec.
3014
 
3015
inline void
3016
Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3017
                                    size_t relnum,
3018
                                    Output_segment*,
3019
                                    const elfcpp::Rel<32, false>& rel,
3020
                                    unsigned int,
3021
                                    elfcpp::Elf_types<32>::Elf_Addr value,
3022
                                    unsigned char* view,
3023
                                    section_size_type view_size)
3024
{
3025
  // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3026
  //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3027
 
3028
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3029
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3030
 
3031
  unsigned char op1 = view[-1];
3032
  unsigned char op2 = view[-2];
3033
 
3034
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3035
                 op2 == 0x8d || op2 == 0x04);
3036
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3037
 
3038
  int roff = 5;
3039
 
3040
  // FIXME: For now, support only the first (SIB) form.
3041
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
3042
 
3043
  if (op2 == 0x04)
3044
    {
3045
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3046
      tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3047
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3048
                     ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3049
      memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3050
    }
3051
  else
3052
    {
3053
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3054
                     (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3055
      if (rel.get_r_offset() + 9 < view_size
3056
          && view[9] == 0x90)
3057
        {
3058
          // FIXME: This is not the right instruction sequence.
3059
          // There is a trailing nop.  Use the size byte subl.
3060
          memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3061
          roff = 6;
3062
        }
3063
      else
3064
        {
3065
          // FIXME: This is not the right instruction sequence.
3066
          // Use the five byte subl.
3067
          memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3068
        }
3069
    }
3070
 
3071
  Relocate_functions<32, false>::rel32(view + roff, value);
3072
 
3073
  // The next reloc should be a PLT32 reloc against __tls_get_addr.
3074
  // We can skip it.
3075
  this->skip_call_tls_get_addr_ = true;
3076
}
3077
 
3078
// Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3079
// General-Dynamic to a Local-Exec.
3080
 
3081
inline void
3082
Target_i386::Relocate::tls_desc_gd_to_le(
3083
    const Relocate_info<32, false>* relinfo,
3084
    size_t relnum,
3085
    Output_segment* tls_segment,
3086
    const elfcpp::Rel<32, false>& rel,
3087
    unsigned int r_type,
3088
    elfcpp::Elf_types<32>::Elf_Addr value,
3089
    unsigned char* view,
3090
    section_size_type view_size)
3091
{
3092
  if (r_type == elfcpp::R_386_TLS_GOTDESC)
3093
    {
3094
      // leal foo@TLSDESC(%ebx), %eax
3095
      // ==> leal foo@NTPOFF, %eax
3096
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3097
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3098
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3099
                     view[-2] == 0x8d && view[-1] == 0x83);
3100
      view[-1] = 0x05;
3101
      value -= tls_segment->memsz();
3102
      Relocate_functions<32, false>::rel32(view, value);
3103
    }
3104
  else
3105
    {
3106
      // call *foo@TLSCALL(%eax)
3107
      // ==> nop; nop
3108
      gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3109
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3110
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3111
                     view[0] == 0xff && view[1] == 0x10);
3112
      view[0] = 0x66;
3113
      view[1] = 0x90;
3114
    }
3115
}
3116
 
3117
// Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3118
// General-Dynamic to an Initial-Exec.
3119
 
3120
inline void
3121
Target_i386::Relocate::tls_desc_gd_to_ie(
3122
    const Relocate_info<32, false>* relinfo,
3123
    size_t relnum,
3124
    Output_segment*,
3125
    const elfcpp::Rel<32, false>& rel,
3126
    unsigned int r_type,
3127
    elfcpp::Elf_types<32>::Elf_Addr value,
3128
    unsigned char* view,
3129
    section_size_type view_size)
3130
{
3131
  if (r_type == elfcpp::R_386_TLS_GOTDESC)
3132
    {
3133
      // leal foo@TLSDESC(%ebx), %eax
3134
      // ==> movl foo@GOTNTPOFF(%ebx), %eax
3135
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3136
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3137
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3138
                     view[-2] == 0x8d && view[-1] == 0x83);
3139
      view[-2] = 0x8b;
3140
      Relocate_functions<32, false>::rel32(view, value);
3141
    }
3142
  else
3143
    {
3144
      // call *foo@TLSCALL(%eax)
3145
      // ==> nop; nop
3146
      gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3147
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3148
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3149
                     view[0] == 0xff && view[1] == 0x10);
3150
      view[0] = 0x66;
3151
      view[1] = 0x90;
3152
    }
3153
}
3154
 
3155
// Do a relocation in which we convert a TLS Local-Dynamic to a
3156
// Local-Exec.
3157
 
3158
inline void
3159
Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3160
                                    size_t relnum,
3161
                                    Output_segment*,
3162
                                    const elfcpp::Rel<32, false>& rel,
3163
                                    unsigned int,
3164
                                    elfcpp::Elf_types<32>::Elf_Addr,
3165
                                    unsigned char* view,
3166
                                    section_size_type view_size)
3167
{
3168
  // leal foo(%reg), %eax; call ___tls_get_addr
3169
  // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3170
 
3171
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3172
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3173
 
3174
  // FIXME: Does this test really always pass?
3175
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3176
                 view[-2] == 0x8d && view[-1] == 0x83);
3177
 
3178
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3179
 
3180
  memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3181
 
3182
  // The next reloc should be a PLT32 reloc against __tls_get_addr.
3183
  // We can skip it.
3184
  this->skip_call_tls_get_addr_ = true;
3185
}
3186
 
3187
// Do a relocation in which we convert a TLS Initial-Exec to a
3188
// Local-Exec.
3189
 
3190
inline void
3191
Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3192
                                    size_t relnum,
3193
                                    Output_segment* tls_segment,
3194
                                    const elfcpp::Rel<32, false>& rel,
3195
                                    unsigned int r_type,
3196
                                    elfcpp::Elf_types<32>::Elf_Addr value,
3197
                                    unsigned char* view,
3198
                                    section_size_type view_size)
3199
{
3200
  // We have to actually change the instructions, which means that we
3201
  // need to examine the opcodes to figure out which instruction we
3202
  // are looking at.
3203
  if (r_type == elfcpp::R_386_TLS_IE)
3204
    {
3205
      // movl %gs:XX,%eax  ==>  movl $YY,%eax
3206
      // movl %gs:XX,%reg  ==>  movl $YY,%reg
3207
      // addl %gs:XX,%reg  ==>  addl $YY,%reg
3208
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3209
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3210
 
3211
      unsigned char op1 = view[-1];
3212
      if (op1 == 0xa1)
3213
        {
3214
          // movl XX,%eax  ==>  movl $YY,%eax
3215
          view[-1] = 0xb8;
3216
        }
3217
      else
3218
        {
3219
          tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3220
 
3221
          unsigned char op2 = view[-2];
3222
          if (op2 == 0x8b)
3223
            {
3224
              // movl XX,%reg  ==>  movl $YY,%reg
3225
              tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3226
                             (op1 & 0xc7) == 0x05);
3227
              view[-2] = 0xc7;
3228
              view[-1] = 0xc0 | ((op1 >> 3) & 7);
3229
            }
3230
          else if (op2 == 0x03)
3231
            {
3232
              // addl XX,%reg  ==>  addl $YY,%reg
3233
              tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3234
                             (op1 & 0xc7) == 0x05);
3235
              view[-2] = 0x81;
3236
              view[-1] = 0xc0 | ((op1 >> 3) & 7);
3237
            }
3238
          else
3239
            tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3240
        }
3241
    }
3242
  else
3243
    {
3244
      // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3245
      // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3246
      // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3247
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3248
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3249
 
3250
      unsigned char op1 = view[-1];
3251
      unsigned char op2 = view[-2];
3252
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3253
                     (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3254
      if (op2 == 0x8b)
3255
        {
3256
          // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3257
          view[-2] = 0xc7;
3258
          view[-1] = 0xc0 | ((op1 >> 3) & 7);
3259
        }
3260
      else if (op2 == 0x2b)
3261
        {
3262
          // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3263
          view[-2] = 0x81;
3264
          view[-1] = 0xe8 | ((op1 >> 3) & 7);
3265
        }
3266
      else if (op2 == 0x03)
3267
        {
3268
          // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3269
          view[-2] = 0x81;
3270
          view[-1] = 0xc0 | ((op1 >> 3) & 7);
3271
        }
3272
      else
3273
        tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3274
    }
3275
 
3276
  value = tls_segment->memsz() - value;
3277
  if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3278
    value = - value;
3279
 
3280
  Relocate_functions<32, false>::rel32(view, value);
3281
}
3282
 
3283
// Relocate section data.
3284
 
3285
void
3286
Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3287
                              unsigned int sh_type,
3288
                              const unsigned char* prelocs,
3289
                              size_t reloc_count,
3290
                              Output_section* output_section,
3291
                              bool needs_special_offset_handling,
3292
                              unsigned char* view,
3293
                              elfcpp::Elf_types<32>::Elf_Addr address,
3294
                              section_size_type view_size,
3295
                              const Reloc_symbol_changes* reloc_symbol_changes)
3296
{
3297
  gold_assert(sh_type == elfcpp::SHT_REL);
3298
 
3299
  gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
3300
                         Target_i386::Relocate>(
3301
    relinfo,
3302
    this,
3303
    prelocs,
3304
    reloc_count,
3305
    output_section,
3306
    needs_special_offset_handling,
3307
    view,
3308
    address,
3309
    view_size,
3310
    reloc_symbol_changes);
3311
}
3312
 
3313
// Return the size of a relocation while scanning during a relocatable
3314
// link.
3315
 
3316
unsigned int
3317
Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3318
    unsigned int r_type,
3319
    Relobj* object)
3320
{
3321
  switch (r_type)
3322
    {
3323
    case elfcpp::R_386_NONE:
3324
    case elfcpp::R_386_GNU_VTINHERIT:
3325
    case elfcpp::R_386_GNU_VTENTRY:
3326
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
3327
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
3328
    case elfcpp::R_386_TLS_DESC_CALL:
3329
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
3330
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
3331
    case elfcpp::R_386_TLS_IE:            // Initial-exec
3332
    case elfcpp::R_386_TLS_IE_32:
3333
    case elfcpp::R_386_TLS_GOTIE:
3334
    case elfcpp::R_386_TLS_LE:            // Local-exec
3335
    case elfcpp::R_386_TLS_LE_32:
3336
      return 0;
3337
 
3338
    case elfcpp::R_386_32:
3339
    case elfcpp::R_386_PC32:
3340
    case elfcpp::R_386_GOT32:
3341
    case elfcpp::R_386_PLT32:
3342
    case elfcpp::R_386_GOTOFF:
3343
    case elfcpp::R_386_GOTPC:
3344
     return 4;
3345
 
3346
    case elfcpp::R_386_16:
3347
    case elfcpp::R_386_PC16:
3348
      return 2;
3349
 
3350
    case elfcpp::R_386_8:
3351
    case elfcpp::R_386_PC8:
3352
      return 1;
3353
 
3354
      // These are relocations which should only be seen by the
3355
      // dynamic linker, and should never be seen here.
3356
    case elfcpp::R_386_COPY:
3357
    case elfcpp::R_386_GLOB_DAT:
3358
    case elfcpp::R_386_JUMP_SLOT:
3359
    case elfcpp::R_386_RELATIVE:
3360
    case elfcpp::R_386_IRELATIVE:
3361
    case elfcpp::R_386_TLS_TPOFF:
3362
    case elfcpp::R_386_TLS_DTPMOD32:
3363
    case elfcpp::R_386_TLS_DTPOFF32:
3364
    case elfcpp::R_386_TLS_TPOFF32:
3365
    case elfcpp::R_386_TLS_DESC:
3366
      object->error(_("unexpected reloc %u in object file"), r_type);
3367
      return 0;
3368
 
3369
    case elfcpp::R_386_32PLT:
3370
    case elfcpp::R_386_TLS_GD_32:
3371
    case elfcpp::R_386_TLS_GD_PUSH:
3372
    case elfcpp::R_386_TLS_GD_CALL:
3373
    case elfcpp::R_386_TLS_GD_POP:
3374
    case elfcpp::R_386_TLS_LDM_32:
3375
    case elfcpp::R_386_TLS_LDM_PUSH:
3376
    case elfcpp::R_386_TLS_LDM_CALL:
3377
    case elfcpp::R_386_TLS_LDM_POP:
3378
    case elfcpp::R_386_USED_BY_INTEL_200:
3379
    default:
3380
      object->error(_("unsupported reloc %u in object file"), r_type);
3381
      return 0;
3382
    }
3383
}
3384
 
3385
// Scan the relocs during a relocatable link.
3386
 
3387
void
3388
Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3389
                                     Layout* layout,
3390
                                     Sized_relobj_file<32, false>* object,
3391
                                     unsigned int data_shndx,
3392
                                     unsigned int sh_type,
3393
                                     const unsigned char* prelocs,
3394
                                     size_t reloc_count,
3395
                                     Output_section* output_section,
3396
                                     bool needs_special_offset_handling,
3397
                                     size_t local_symbol_count,
3398
                                     const unsigned char* plocal_symbols,
3399
                                     Relocatable_relocs* rr)
3400
{
3401
  gold_assert(sh_type == elfcpp::SHT_REL);
3402
 
3403
  typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3404
    Relocatable_size_for_reloc> Scan_relocatable_relocs;
3405
 
3406
  gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3407
      Scan_relocatable_relocs>(
3408
    symtab,
3409
    layout,
3410
    object,
3411
    data_shndx,
3412
    prelocs,
3413
    reloc_count,
3414
    output_section,
3415
    needs_special_offset_handling,
3416
    local_symbol_count,
3417
    plocal_symbols,
3418
    rr);
3419
}
3420
 
3421
// Relocate a section during a relocatable link.
3422
 
3423
void
3424
Target_i386::relocate_for_relocatable(
3425
    const Relocate_info<32, false>* relinfo,
3426
    unsigned int sh_type,
3427
    const unsigned char* prelocs,
3428
    size_t reloc_count,
3429
    Output_section* output_section,
3430
    off_t offset_in_output_section,
3431
    const Relocatable_relocs* rr,
3432
    unsigned char* view,
3433
    elfcpp::Elf_types<32>::Elf_Addr view_address,
3434
    section_size_type view_size,
3435
    unsigned char* reloc_view,
3436
    section_size_type reloc_view_size)
3437
{
3438
  gold_assert(sh_type == elfcpp::SHT_REL);
3439
 
3440
  gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
3441
    relinfo,
3442
    prelocs,
3443
    reloc_count,
3444
    output_section,
3445
    offset_in_output_section,
3446
    rr,
3447
    view,
3448
    view_address,
3449
    view_size,
3450
    reloc_view,
3451
    reloc_view_size);
3452
}
3453
 
3454
// Return the value to use for a dynamic which requires special
3455
// treatment.  This is how we support equality comparisons of function
3456
// pointers across shared library boundaries, as described in the
3457
// processor specific ABI supplement.
3458
 
3459
uint64_t
3460
Target_i386::do_dynsym_value(const Symbol* gsym) const
3461
{
3462
  gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3463 159 khays
  return this->plt_address_for_global(gsym) + gsym->plt_offset();
3464 27 khays
}
3465
 
3466
// Return a string used to fill a code section with nops to take up
3467
// the specified length.
3468
 
3469
std::string
3470
Target_i386::do_code_fill(section_size_type length) const
3471
{
3472
  if (length >= 16)
3473
    {
3474
      // Build a jmp instruction to skip over the bytes.
3475
      unsigned char jmp[5];
3476
      jmp[0] = 0xe9;
3477
      elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3478
      return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3479
              + std::string(length - 5, '\0'));
3480
    }
3481
 
3482
  // Nop sequences of various lengths.
3483
  const char nop1[1] = { 0x90 };                   // nop
3484
  const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
3485
  const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
3486
  const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
3487
  const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
3488
                         0x00 };                   // leal 0(%esi,1),%esi
3489
  const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
3490
                         0x00, 0x00 };
3491
  const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
3492
                         0x00, 0x00, 0x00 };
3493
  const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
3494
                         0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3495
  const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
3496
                         0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
3497
                         0x00 };
3498
  const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3499
                           0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3500
                           0x00, 0x00 };
3501
  const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3502
                           0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3503
                           0x00, 0x00, 0x00 };
3504
  const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3505
                           0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3506
                           0x00, 0x00, 0x00, 0x00 };
3507
  const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3508
                           0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3509
                           0x27, 0x00, 0x00, 0x00,
3510
                           0x00 };
3511
  const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3512
                           0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3513
                           0xbc, 0x27, 0x00, 0x00,
3514
                           0x00, 0x00 };
3515
  const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3516
                           0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3517
                           0x90, 0x90, 0x90, 0x90,
3518
                           0x90, 0x90, 0x90 };
3519
 
3520
  const char* nops[16] = {
3521
    NULL,
3522
    nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3523
    nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3524
  };
3525
 
3526
  return std::string(nops[length], length);
3527
}
3528
 
3529 159 khays
// Return the value to use for the base of a DW_EH_PE_datarel offset
3530
// in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
3531
// assembler can not write out the difference between two labels in
3532
// different sections, so instead of using a pc-relative value they
3533
// use an offset from the GOT.
3534
 
3535
uint64_t
3536
Target_i386::do_ehframe_datarel_base() const
3537
{
3538
  gold_assert(this->global_offset_table_ != NULL);
3539
  Symbol* sym = this->global_offset_table_;
3540
  Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3541
  return ssym->value();
3542
}
3543
 
3544 27 khays
// Return whether SYM should be treated as a call to a non-split
3545
// function.  We don't want that to be true of a call to a
3546
// get_pc_thunk function.
3547
 
3548
bool
3549
Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3550
{
3551
  return (sym->type() == elfcpp::STT_FUNC
3552
          && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3553
}
3554
 
3555
// FNOFFSET in section SHNDX in OBJECT is the start of a function
3556
// compiled with -fsplit-stack.  The function calls non-split-stack
3557
// code.  We have to change the function so that it always ensures
3558
// that it has enough stack space to run some random function.
3559
 
3560
void
3561
Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3562
                                section_offset_type fnoffset,
3563
                                section_size_type fnsize,
3564
                                unsigned char* view,
3565
                                section_size_type view_size,
3566
                                std::string* from,
3567
                                std::string* to) const
3568
{
3569
  // The function starts with a comparison of the stack pointer and a
3570
  // field in the TCB.  This is followed by a jump.
3571
 
3572
  // cmp %gs:NN,%esp
3573
  if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3574
      && fnsize > 7)
3575
    {
3576
      // We will call __morestack if the carry flag is set after this
3577
      // comparison.  We turn the comparison into an stc instruction
3578
      // and some nops.
3579
      view[fnoffset] = '\xf9';
3580
      this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3581
    }
3582
  // lea NN(%esp),%ecx
3583
  // lea NN(%esp),%edx
3584
  else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3585
            || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3586
           && fnsize > 7)
3587
    {
3588
      // This is loading an offset from the stack pointer for a
3589
      // comparison.  The offset is negative, so we decrease the
3590
      // offset by the amount of space we need for the stack.  This
3591
      // means we will avoid calling __morestack if there happens to
3592
      // be plenty of space on the stack already.
3593
      unsigned char* pval = view + fnoffset + 3;
3594
      uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3595
      val -= parameters->options().split_stack_adjust_size();
3596
      elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3597
    }
3598
  else
3599
    {
3600
      if (!object->has_no_split_stack())
3601
        object->error(_("failed to match split-stack sequence at "
3602
                        "section %u offset %0zx"),
3603
                      shndx, static_cast<size_t>(fnoffset));
3604
      return;
3605
    }
3606
 
3607
  // We have to change the function so that it calls
3608
  // __morestack_non_split instead of __morestack.  The former will
3609
  // allocate additional stack space.
3610
  *from = "__morestack";
3611
  *to = "__morestack_non_split";
3612
}
3613
 
3614
// The selector for i386 object files.
3615
 
3616
class Target_selector_i386 : public Target_selector_freebsd
3617
{
3618
public:
3619
  Target_selector_i386()
3620
    : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3621 159 khays
                              "elf32-i386", "elf32-i386-freebsd",
3622
                              "elf_i386")
3623 27 khays
  { }
3624
 
3625
  Target*
3626
  do_instantiate_target()
3627
  { return new Target_i386(); }
3628
};
3629
 
3630
Target_selector_i386 target_selector_i386;
3631
 
3632
} // End anonymous namespace.

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