* i386.cc (Relocate::relocate): Fix typos for R_386_PC16 and
[deliverable/binutils-gdb.git] / gold / i386.cc
1 // i386.cc -- i386 target support for gold.
2
3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cstring>
26
27 #include "elfcpp.h"
28 #include "parameters.h"
29 #include "reloc.h"
30 #include "i386.h"
31 #include "object.h"
32 #include "symtab.h"
33 #include "layout.h"
34 #include "output.h"
35 #include "copy-relocs.h"
36 #include "target.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
39 #include "tls.h"
40
41 namespace
42 {
43
44 using namespace gold;
45
46 class Output_data_plt_i386;
47
48 // The i386 target class.
49 // TLS info comes from
50 // http://people.redhat.com/drepper/tls.pdf
51 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
52
53 class Target_i386 : public Sized_target<32, false>
54 {
55 public:
56 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
57
58 Target_i386()
59 : Sized_target<32, false>(&i386_info),
60 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
61 copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
62 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
63 { }
64
65 // Scan the relocations to look for symbol adjustments.
66 void
67 scan_relocs(const General_options& options,
68 Symbol_table* symtab,
69 Layout* layout,
70 Sized_relobj<32, false>* object,
71 unsigned int data_shndx,
72 unsigned int sh_type,
73 const unsigned char* prelocs,
74 size_t reloc_count,
75 Output_section* output_section,
76 bool needs_special_offset_handling,
77 size_t local_symbol_count,
78 const unsigned char* plocal_symbols);
79
80 // Finalize the sections.
81 void
82 do_finalize_sections(Layout*);
83
84 // Return the value to use for a dynamic which requires special
85 // treatment.
86 uint64_t
87 do_dynsym_value(const Symbol*) const;
88
89 // Relocate a section.
90 void
91 relocate_section(const Relocate_info<32, false>*,
92 unsigned int sh_type,
93 const unsigned char* prelocs,
94 size_t reloc_count,
95 Output_section* output_section,
96 bool needs_special_offset_handling,
97 unsigned char* view,
98 elfcpp::Elf_types<32>::Elf_Addr view_address,
99 section_size_type view_size);
100
101 // Scan the relocs during a relocatable link.
102 void
103 scan_relocatable_relocs(const General_options& options,
104 Symbol_table* symtab,
105 Layout* layout,
106 Sized_relobj<32, false>* object,
107 unsigned int data_shndx,
108 unsigned int sh_type,
109 const unsigned char* prelocs,
110 size_t reloc_count,
111 Output_section* output_section,
112 bool needs_special_offset_handling,
113 size_t local_symbol_count,
114 const unsigned char* plocal_symbols,
115 Relocatable_relocs*);
116
117 // Relocate a section during a relocatable link.
118 void
119 relocate_for_relocatable(const Relocate_info<32, false>*,
120 unsigned int sh_type,
121 const unsigned char* prelocs,
122 size_t reloc_count,
123 Output_section* output_section,
124 off_t offset_in_output_section,
125 const Relocatable_relocs*,
126 unsigned char* view,
127 elfcpp::Elf_types<32>::Elf_Addr view_address,
128 section_size_type view_size,
129 unsigned char* reloc_view,
130 section_size_type reloc_view_size);
131
132 // Return a string used to fill a code section with nops.
133 std::string
134 do_code_fill(section_size_type length) const;
135
136 // Return whether SYM is defined by the ABI.
137 bool
138 do_is_defined_by_abi(Symbol* sym) const
139 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
140
141 // Return the size of the GOT section.
142 section_size_type
143 got_size()
144 {
145 gold_assert(this->got_ != NULL);
146 return this->got_->data_size();
147 }
148
149 private:
150 // The class which scans relocations.
151 struct Scan
152 {
153 inline void
154 local(const General_options& options, Symbol_table* symtab,
155 Layout* layout, Target_i386* target,
156 Sized_relobj<32, false>* object,
157 unsigned int data_shndx,
158 Output_section* output_section,
159 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
160 const elfcpp::Sym<32, false>& lsym);
161
162 inline void
163 global(const General_options& options, Symbol_table* symtab,
164 Layout* layout, Target_i386* target,
165 Sized_relobj<32, false>* object,
166 unsigned int data_shndx,
167 Output_section* output_section,
168 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
169 Symbol* gsym);
170
171 static void
172 unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
173
174 static void
175 unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
176 Symbol*);
177 };
178
179 // The class which implements relocation.
180 class Relocate
181 {
182 public:
183 Relocate()
184 : skip_call_tls_get_addr_(false),
185 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
186 { }
187
188 ~Relocate()
189 {
190 if (this->skip_call_tls_get_addr_)
191 {
192 // FIXME: This needs to specify the location somehow.
193 gold_error(_("missing expected TLS relocation"));
194 }
195 }
196
197 // Return whether the static relocation needs to be applied.
198 inline bool
199 should_apply_static_reloc(const Sized_symbol<32>* gsym,
200 int ref_flags,
201 bool is_32bit);
202
203 // Do a relocation. Return false if the caller should not issue
204 // any warnings about this relocation.
205 inline bool
206 relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
207 const elfcpp::Rel<32, false>&,
208 unsigned int r_type, const Sized_symbol<32>*,
209 const Symbol_value<32>*,
210 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
211 section_size_type);
212
213 private:
214 // Do a TLS relocation.
215 inline void
216 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
217 size_t relnum, const elfcpp::Rel<32, false>&,
218 unsigned int r_type, const Sized_symbol<32>*,
219 const Symbol_value<32>*,
220 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
221 section_size_type);
222
223 // Do a TLS General-Dynamic to Initial-Exec transition.
224 inline void
225 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
226 Output_segment* tls_segment,
227 const elfcpp::Rel<32, false>&, unsigned int r_type,
228 elfcpp::Elf_types<32>::Elf_Addr value,
229 unsigned char* view,
230 section_size_type view_size);
231
232 // Do a TLS General-Dynamic to Local-Exec transition.
233 inline void
234 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
235 Output_segment* tls_segment,
236 const elfcpp::Rel<32, false>&, unsigned int r_type,
237 elfcpp::Elf_types<32>::Elf_Addr value,
238 unsigned char* view,
239 section_size_type view_size);
240
241 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
242 // transition.
243 inline void
244 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
245 Output_segment* tls_segment,
246 const elfcpp::Rel<32, false>&, unsigned int r_type,
247 elfcpp::Elf_types<32>::Elf_Addr value,
248 unsigned char* view,
249 section_size_type view_size);
250
251 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
252 // transition.
253 inline void
254 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
255 Output_segment* tls_segment,
256 const elfcpp::Rel<32, false>&, unsigned int r_type,
257 elfcpp::Elf_types<32>::Elf_Addr value,
258 unsigned char* view,
259 section_size_type view_size);
260
261 // Do a TLS Local-Dynamic to Local-Exec transition.
262 inline void
263 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
264 Output_segment* tls_segment,
265 const elfcpp::Rel<32, false>&, unsigned int r_type,
266 elfcpp::Elf_types<32>::Elf_Addr value,
267 unsigned char* view,
268 section_size_type view_size);
269
270 // Do a TLS Initial-Exec to Local-Exec transition.
271 static inline void
272 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
273 Output_segment* tls_segment,
274 const elfcpp::Rel<32, false>&, unsigned int r_type,
275 elfcpp::Elf_types<32>::Elf_Addr value,
276 unsigned char* view,
277 section_size_type view_size);
278
279 // We need to keep track of which type of local dynamic relocation
280 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
281 enum Local_dynamic_type
282 {
283 LOCAL_DYNAMIC_NONE,
284 LOCAL_DYNAMIC_SUN,
285 LOCAL_DYNAMIC_GNU
286 };
287
288 // This is set if we should skip the next reloc, which should be a
289 // PLT32 reloc against ___tls_get_addr.
290 bool skip_call_tls_get_addr_;
291 // The type of local dynamic relocation we have seen in the section
292 // being relocated, if any.
293 Local_dynamic_type local_dynamic_type_;
294 };
295
296 // A class which returns the size required for a relocation type,
297 // used while scanning relocs during a relocatable link.
298 class Relocatable_size_for_reloc
299 {
300 public:
301 unsigned int
302 get_size_for_reloc(unsigned int, Relobj*);
303 };
304
305 // Adjust TLS relocation type based on the options and whether this
306 // is a local symbol.
307 static tls::Tls_optimization
308 optimize_tls_reloc(bool is_final, int r_type);
309
310 // Get the GOT section, creating it if necessary.
311 Output_data_got<32, false>*
312 got_section(Symbol_table*, Layout*);
313
314 // Get the GOT PLT section.
315 Output_data_space*
316 got_plt_section() const
317 {
318 gold_assert(this->got_plt_ != NULL);
319 return this->got_plt_;
320 }
321
322 // Create a PLT entry for a global symbol.
323 void
324 make_plt_entry(Symbol_table*, Layout*, Symbol*);
325
326 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
327 void
328 define_tls_base_symbol(Symbol_table*, Layout*);
329
330 // Create a GOT entry for the TLS module index.
331 unsigned int
332 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
333 Sized_relobj<32, false>* object);
334
335 // Get the PLT section.
336 const Output_data_plt_i386*
337 plt_section() const
338 {
339 gold_assert(this->plt_ != NULL);
340 return this->plt_;
341 }
342
343 // Get the dynamic reloc section, creating it if necessary.
344 Reloc_section*
345 rel_dyn_section(Layout*);
346
347 // Return true if the symbol may need a COPY relocation.
348 // References from an executable object to non-function symbols
349 // defined in a dynamic object may need a COPY relocation.
350 bool
351 may_need_copy_reloc(Symbol* gsym)
352 {
353 return (!parameters->options().shared()
354 && gsym->is_from_dynobj()
355 && gsym->type() != elfcpp::STT_FUNC);
356 }
357
358 // Add a potential copy relocation.
359 void
360 copy_reloc(Symbol_table* symtab, Layout* layout, Relobj* object,
361 unsigned int shndx, Output_section* output_section,
362 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
363 {
364 this->copy_relocs_.copy_reloc(symtab, layout,
365 symtab->get_sized_symbol<32>(sym),
366 object, shndx, output_section, reloc,
367 this->rel_dyn_section(layout));
368 }
369
370 // Information about this specific target which we pass to the
371 // general Target structure.
372 static const Target::Target_info i386_info;
373
374 // The types of GOT entries needed for this platform.
375 enum Got_type
376 {
377 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
378 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
379 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
380 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
381 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
382 };
383
384 // The GOT section.
385 Output_data_got<32, false>* got_;
386 // The PLT section.
387 Output_data_plt_i386* plt_;
388 // The GOT PLT section.
389 Output_data_space* got_plt_;
390 // The dynamic reloc section.
391 Reloc_section* rel_dyn_;
392 // Relocs saved to avoid a COPY reloc.
393 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
394 // Space for variables copied with a COPY reloc.
395 Output_data_space* dynbss_;
396 // Offset of the GOT entry for the TLS module index.
397 unsigned int got_mod_index_offset_;
398 // True if the _TLS_MODULE_BASE_ symbol has been defined.
399 bool tls_base_symbol_defined_;
400 };
401
402 const Target::Target_info Target_i386::i386_info =
403 {
404 32, // size
405 false, // is_big_endian
406 elfcpp::EM_386, // machine_code
407 false, // has_make_symbol
408 false, // has_resolve
409 true, // has_code_fill
410 true, // is_default_stack_executable
411 '\0', // wrap_char
412 "/usr/lib/libc.so.1", // dynamic_linker
413 0x08048000, // default_text_segment_address
414 0x1000, // abi_pagesize (overridable by -z max-page-size)
415 0x1000 // common_pagesize (overridable by -z common-page-size)
416 };
417
418 // Get the GOT section, creating it if necessary.
419
420 Output_data_got<32, false>*
421 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
422 {
423 if (this->got_ == NULL)
424 {
425 gold_assert(symtab != NULL && layout != NULL);
426
427 this->got_ = new Output_data_got<32, false>();
428
429 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
430 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
431 this->got_);
432
433 // The old GNU linker creates a .got.plt section. We just
434 // create another set of data in the .got section. Note that we
435 // always create a PLT if we create a GOT, although the PLT
436 // might be empty.
437 this->got_plt_ = new Output_data_space(4);
438 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
439 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
440 this->got_plt_);
441
442 // The first three entries are reserved.
443 this->got_plt_->set_current_data_size(3 * 4);
444
445 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
446 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
447 this->got_plt_,
448 0, 0, elfcpp::STT_OBJECT,
449 elfcpp::STB_LOCAL,
450 elfcpp::STV_HIDDEN, 0,
451 false, false);
452 }
453
454 return this->got_;
455 }
456
457 // Get the dynamic reloc section, creating it if necessary.
458
459 Target_i386::Reloc_section*
460 Target_i386::rel_dyn_section(Layout* layout)
461 {
462 if (this->rel_dyn_ == NULL)
463 {
464 gold_assert(layout != NULL);
465 this->rel_dyn_ = new Reloc_section();
466 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
467 elfcpp::SHF_ALLOC, this->rel_dyn_);
468 }
469 return this->rel_dyn_;
470 }
471
472 // A class to handle the PLT data.
473
474 class Output_data_plt_i386 : public Output_section_data
475 {
476 public:
477 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
478
479 Output_data_plt_i386(Layout*, Output_data_space*);
480
481 // Add an entry to the PLT.
482 void
483 add_entry(Symbol* gsym);
484
485 // Return the .rel.plt section data.
486 const Reloc_section*
487 rel_plt() const
488 { return this->rel_; }
489
490 protected:
491 void
492 do_adjust_output_section(Output_section* os);
493
494 private:
495 // The size of an entry in the PLT.
496 static const int plt_entry_size = 16;
497
498 // The first entry in the PLT for an executable.
499 static unsigned char exec_first_plt_entry[plt_entry_size];
500
501 // The first entry in the PLT for a shared object.
502 static unsigned char dyn_first_plt_entry[plt_entry_size];
503
504 // Other entries in the PLT for an executable.
505 static unsigned char exec_plt_entry[plt_entry_size];
506
507 // Other entries in the PLT for a shared object.
508 static unsigned char dyn_plt_entry[plt_entry_size];
509
510 // Set the final size.
511 void
512 set_final_data_size()
513 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
514
515 // Write out the PLT data.
516 void
517 do_write(Output_file*);
518
519 // The reloc section.
520 Reloc_section* rel_;
521 // The .got.plt section.
522 Output_data_space* got_plt_;
523 // The number of PLT entries.
524 unsigned int count_;
525 };
526
527 // Create the PLT section. The ordinary .got section is an argument,
528 // since we need to refer to the start. We also create our own .got
529 // section just for PLT entries.
530
531 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
532 Output_data_space* got_plt)
533 : Output_section_data(4), got_plt_(got_plt), count_(0)
534 {
535 this->rel_ = new Reloc_section();
536 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
537 elfcpp::SHF_ALLOC, this->rel_);
538 }
539
540 void
541 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
542 {
543 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
544 // linker, and so do we.
545 os->set_entsize(4);
546 }
547
548 // Add an entry to the PLT.
549
550 void
551 Output_data_plt_i386::add_entry(Symbol* gsym)
552 {
553 gold_assert(!gsym->has_plt_offset());
554
555 // Note that when setting the PLT offset we skip the initial
556 // reserved PLT entry.
557 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
558
559 ++this->count_;
560
561 section_offset_type got_offset = this->got_plt_->current_data_size();
562
563 // Every PLT entry needs a GOT entry which points back to the PLT
564 // entry (this will be changed by the dynamic linker, normally
565 // lazily when the function is called).
566 this->got_plt_->set_current_data_size(got_offset + 4);
567
568 // Every PLT entry needs a reloc.
569 gsym->set_needs_dynsym_entry();
570 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
571 got_offset);
572
573 // Note that we don't need to save the symbol. The contents of the
574 // PLT are independent of which symbols are used. The symbols only
575 // appear in the relocations.
576 }
577
578 // The first entry in the PLT for an executable.
579
580 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
581 {
582 0xff, 0x35, // pushl contents of memory address
583 0, 0, 0, 0, // replaced with address of .got + 4
584 0xff, 0x25, // jmp indirect
585 0, 0, 0, 0, // replaced with address of .got + 8
586 0, 0, 0, 0 // unused
587 };
588
589 // The first entry in the PLT for a shared object.
590
591 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
592 {
593 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
594 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
595 0, 0, 0, 0 // unused
596 };
597
598 // Subsequent entries in the PLT for an executable.
599
600 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
601 {
602 0xff, 0x25, // jmp indirect
603 0, 0, 0, 0, // replaced with address of symbol in .got
604 0x68, // pushl immediate
605 0, 0, 0, 0, // replaced with offset into relocation table
606 0xe9, // jmp relative
607 0, 0, 0, 0 // replaced with offset to start of .plt
608 };
609
610 // Subsequent entries in the PLT for a shared object.
611
612 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
613 {
614 0xff, 0xa3, // jmp *offset(%ebx)
615 0, 0, 0, 0, // replaced with offset of symbol in .got
616 0x68, // pushl immediate
617 0, 0, 0, 0, // replaced with offset into relocation table
618 0xe9, // jmp relative
619 0, 0, 0, 0 // replaced with offset to start of .plt
620 };
621
622 // Write out the PLT. This uses the hand-coded instructions above,
623 // and adjusts them as needed. This is all specified by the i386 ELF
624 // Processor Supplement.
625
626 void
627 Output_data_plt_i386::do_write(Output_file* of)
628 {
629 const off_t offset = this->offset();
630 const section_size_type oview_size =
631 convert_to_section_size_type(this->data_size());
632 unsigned char* const oview = of->get_output_view(offset, oview_size);
633
634 const off_t got_file_offset = this->got_plt_->offset();
635 const section_size_type got_size =
636 convert_to_section_size_type(this->got_plt_->data_size());
637 unsigned char* const got_view = of->get_output_view(got_file_offset,
638 got_size);
639
640 unsigned char* pov = oview;
641
642 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
643 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
644
645 if (parameters->options().shared())
646 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
647 else
648 {
649 memcpy(pov, exec_first_plt_entry, plt_entry_size);
650 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
651 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
652 }
653 pov += plt_entry_size;
654
655 unsigned char* got_pov = got_view;
656
657 memset(got_pov, 0, 12);
658 got_pov += 12;
659
660 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
661
662 unsigned int plt_offset = plt_entry_size;
663 unsigned int plt_rel_offset = 0;
664 unsigned int got_offset = 12;
665 const unsigned int count = this->count_;
666 for (unsigned int i = 0;
667 i < count;
668 ++i,
669 pov += plt_entry_size,
670 got_pov += 4,
671 plt_offset += plt_entry_size,
672 plt_rel_offset += rel_size,
673 got_offset += 4)
674 {
675 // Set and adjust the PLT entry itself.
676
677 if (parameters->options().shared())
678 {
679 memcpy(pov, dyn_plt_entry, plt_entry_size);
680 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
681 }
682 else
683 {
684 memcpy(pov, exec_plt_entry, plt_entry_size);
685 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
686 (got_address
687 + got_offset));
688 }
689
690 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
691 elfcpp::Swap<32, false>::writeval(pov + 12,
692 - (plt_offset + plt_entry_size));
693
694 // Set the entry in the GOT.
695 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
696 }
697
698 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
699 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
700
701 of->write_output_view(offset, oview_size, oview);
702 of->write_output_view(got_file_offset, got_size, got_view);
703 }
704
705 // Create a PLT entry for a global symbol.
706
707 void
708 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
709 {
710 if (gsym->has_plt_offset())
711 return;
712
713 if (this->plt_ == NULL)
714 {
715 // Create the GOT sections first.
716 this->got_section(symtab, layout);
717
718 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
719 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
720 (elfcpp::SHF_ALLOC
721 | elfcpp::SHF_EXECINSTR),
722 this->plt_);
723 }
724
725 this->plt_->add_entry(gsym);
726 }
727
728 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
729
730 void
731 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
732 {
733 if (this->tls_base_symbol_defined_)
734 return;
735
736 Output_segment* tls_segment = layout->tls_segment();
737 if (tls_segment != NULL)
738 {
739 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
740 tls_segment, 0, 0,
741 elfcpp::STT_TLS,
742 elfcpp::STB_LOCAL,
743 elfcpp::STV_HIDDEN, 0,
744 Symbol::SEGMENT_END, true);
745 }
746 this->tls_base_symbol_defined_ = true;
747 }
748
749 // Create a GOT entry for the TLS module index.
750
751 unsigned int
752 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
753 Sized_relobj<32, false>* object)
754 {
755 if (this->got_mod_index_offset_ == -1U)
756 {
757 gold_assert(symtab != NULL && layout != NULL && object != NULL);
758 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
759 Output_data_got<32, false>* got = this->got_section(symtab, layout);
760 unsigned int got_offset = got->add_constant(0);
761 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
762 got_offset);
763 got->add_constant(0);
764 this->got_mod_index_offset_ = got_offset;
765 }
766 return this->got_mod_index_offset_;
767 }
768
769 // Optimize the TLS relocation type based on what we know about the
770 // symbol. IS_FINAL is true if the final address of this symbol is
771 // known at link time.
772
773 tls::Tls_optimization
774 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
775 {
776 // If we are generating a shared library, then we can't do anything
777 // in the linker.
778 if (parameters->options().shared())
779 return tls::TLSOPT_NONE;
780
781 switch (r_type)
782 {
783 case elfcpp::R_386_TLS_GD:
784 case elfcpp::R_386_TLS_GOTDESC:
785 case elfcpp::R_386_TLS_DESC_CALL:
786 // These are General-Dynamic which permits fully general TLS
787 // access. Since we know that we are generating an executable,
788 // we can convert this to Initial-Exec. If we also know that
789 // this is a local symbol, we can further switch to Local-Exec.
790 if (is_final)
791 return tls::TLSOPT_TO_LE;
792 return tls::TLSOPT_TO_IE;
793
794 case elfcpp::R_386_TLS_LDM:
795 // This is Local-Dynamic, which refers to a local symbol in the
796 // dynamic TLS block. Since we know that we generating an
797 // executable, we can switch to Local-Exec.
798 return tls::TLSOPT_TO_LE;
799
800 case elfcpp::R_386_TLS_LDO_32:
801 // Another type of Local-Dynamic relocation.
802 return tls::TLSOPT_TO_LE;
803
804 case elfcpp::R_386_TLS_IE:
805 case elfcpp::R_386_TLS_GOTIE:
806 case elfcpp::R_386_TLS_IE_32:
807 // These are Initial-Exec relocs which get the thread offset
808 // from the GOT. If we know that we are linking against the
809 // local symbol, we can switch to Local-Exec, which links the
810 // thread offset into the instruction.
811 if (is_final)
812 return tls::TLSOPT_TO_LE;
813 return tls::TLSOPT_NONE;
814
815 case elfcpp::R_386_TLS_LE:
816 case elfcpp::R_386_TLS_LE_32:
817 // When we already have Local-Exec, there is nothing further we
818 // can do.
819 return tls::TLSOPT_NONE;
820
821 default:
822 gold_unreachable();
823 }
824 }
825
826 // Report an unsupported relocation against a local symbol.
827
828 void
829 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
830 unsigned int r_type)
831 {
832 gold_error(_("%s: unsupported reloc %u against local symbol"),
833 object->name().c_str(), r_type);
834 }
835
836 // Scan a relocation for a local symbol.
837
838 inline void
839 Target_i386::Scan::local(const General_options&,
840 Symbol_table* symtab,
841 Layout* layout,
842 Target_i386* target,
843 Sized_relobj<32, false>* object,
844 unsigned int data_shndx,
845 Output_section* output_section,
846 const elfcpp::Rel<32, false>& reloc,
847 unsigned int r_type,
848 const elfcpp::Sym<32, false>& lsym)
849 {
850 switch (r_type)
851 {
852 case elfcpp::R_386_NONE:
853 case elfcpp::R_386_GNU_VTINHERIT:
854 case elfcpp::R_386_GNU_VTENTRY:
855 break;
856
857 case elfcpp::R_386_32:
858 // If building a shared library (or a position-independent
859 // executable), we need to create a dynamic relocation for
860 // this location. The relocation applied at link time will
861 // apply the link-time value, so we flag the location with
862 // an R_386_RELATIVE relocation so the dynamic loader can
863 // relocate it easily.
864 if (parameters->options().output_is_position_independent())
865 {
866 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
867 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
868 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
869 output_section, data_shndx,
870 reloc.get_r_offset());
871 }
872 break;
873
874 case elfcpp::R_386_16:
875 case elfcpp::R_386_8:
876 // If building a shared library (or a position-independent
877 // executable), we need to create a dynamic relocation for
878 // this location. Because the addend needs to remain in the
879 // data section, we need to be careful not to apply this
880 // relocation statically.
881 if (parameters->options().output_is_position_independent())
882 {
883 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
884 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
885 if (lsym.get_st_type() != elfcpp::STT_SECTION)
886 rel_dyn->add_local(object, r_sym, r_type, output_section,
887 data_shndx, reloc.get_r_offset());
888 else
889 {
890 gold_assert(lsym.get_st_value() == 0);
891 unsigned int shndx = lsym.get_st_shndx();
892 bool is_ordinary;
893 shndx = object->adjust_sym_shndx(r_sym, shndx,
894 &is_ordinary);
895 if (!is_ordinary)
896 object->error(_("section symbol %u has bad shndx %u"),
897 r_sym, shndx);
898 else
899 rel_dyn->add_local_section(object, shndx,
900 r_type, output_section,
901 data_shndx, reloc.get_r_offset());
902 }
903 }
904 break;
905
906 case elfcpp::R_386_PC32:
907 case elfcpp::R_386_PC16:
908 case elfcpp::R_386_PC8:
909 break;
910
911 case elfcpp::R_386_PLT32:
912 // Since we know this is a local symbol, we can handle this as a
913 // PC32 reloc.
914 break;
915
916 case elfcpp::R_386_GOTOFF:
917 case elfcpp::R_386_GOTPC:
918 // We need a GOT section.
919 target->got_section(symtab, layout);
920 break;
921
922 case elfcpp::R_386_GOT32:
923 {
924 // The symbol requires a GOT entry.
925 Output_data_got<32, false>* got = target->got_section(symtab, layout);
926 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
927 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
928 {
929 // If we are generating a shared object, we need to add a
930 // dynamic RELATIVE relocation for this symbol's GOT entry.
931 if (parameters->options().output_is_position_independent())
932 {
933 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
934 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
935 rel_dyn->add_local_relative(
936 object, r_sym, elfcpp::R_386_RELATIVE, got,
937 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
938 }
939 }
940 }
941 break;
942
943 // These are relocations which should only be seen by the
944 // dynamic linker, and should never be seen here.
945 case elfcpp::R_386_COPY:
946 case elfcpp::R_386_GLOB_DAT:
947 case elfcpp::R_386_JUMP_SLOT:
948 case elfcpp::R_386_RELATIVE:
949 case elfcpp::R_386_TLS_TPOFF:
950 case elfcpp::R_386_TLS_DTPMOD32:
951 case elfcpp::R_386_TLS_DTPOFF32:
952 case elfcpp::R_386_TLS_TPOFF32:
953 case elfcpp::R_386_TLS_DESC:
954 gold_error(_("%s: unexpected reloc %u in object file"),
955 object->name().c_str(), r_type);
956 break;
957
958 // These are initial TLS relocs, which are expected when
959 // linking.
960 case elfcpp::R_386_TLS_GD: // Global-dynamic
961 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
962 case elfcpp::R_386_TLS_DESC_CALL:
963 case elfcpp::R_386_TLS_LDM: // Local-dynamic
964 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
965 case elfcpp::R_386_TLS_IE: // Initial-exec
966 case elfcpp::R_386_TLS_IE_32:
967 case elfcpp::R_386_TLS_GOTIE:
968 case elfcpp::R_386_TLS_LE: // Local-exec
969 case elfcpp::R_386_TLS_LE_32:
970 {
971 bool output_is_shared = parameters->options().shared();
972 const tls::Tls_optimization optimized_type
973 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
974 switch (r_type)
975 {
976 case elfcpp::R_386_TLS_GD: // Global-dynamic
977 if (optimized_type == tls::TLSOPT_NONE)
978 {
979 // Create a pair of GOT entries for the module index and
980 // dtv-relative offset.
981 Output_data_got<32, false>* got
982 = target->got_section(symtab, layout);
983 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
984 unsigned int shndx = lsym.get_st_shndx();
985 bool is_ordinary;
986 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
987 if (!is_ordinary)
988 object->error(_("local symbol %u has bad shndx %u"),
989 r_sym, shndx);
990 else
991 got->add_local_pair_with_rel(object, r_sym, shndx,
992 GOT_TYPE_TLS_PAIR,
993 target->rel_dyn_section(layout),
994 elfcpp::R_386_TLS_DTPMOD32, 0);
995 }
996 else if (optimized_type != tls::TLSOPT_TO_LE)
997 unsupported_reloc_local(object, r_type);
998 break;
999
1000 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1001 target->define_tls_base_symbol(symtab, layout);
1002 if (optimized_type == tls::TLSOPT_NONE)
1003 {
1004 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1005 Output_data_got<32, false>* got
1006 = target->got_section(symtab, layout);
1007 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1008 unsigned int shndx = lsym.get_st_shndx();
1009 bool is_ordinary;
1010 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1011 if (!is_ordinary)
1012 object->error(_("local symbol %u has bad shndx %u"),
1013 r_sym, shndx);
1014 else
1015 got->add_local_pair_with_rel(object, r_sym, shndx,
1016 GOT_TYPE_TLS_DESC,
1017 target->rel_dyn_section(layout),
1018 elfcpp::R_386_TLS_DESC, 0);
1019 }
1020 else if (optimized_type != tls::TLSOPT_TO_LE)
1021 unsupported_reloc_local(object, r_type);
1022 break;
1023
1024 case elfcpp::R_386_TLS_DESC_CALL:
1025 break;
1026
1027 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1028 if (optimized_type == tls::TLSOPT_NONE)
1029 {
1030 // Create a GOT entry for the module index.
1031 target->got_mod_index_entry(symtab, layout, object);
1032 }
1033 else if (optimized_type != tls::TLSOPT_TO_LE)
1034 unsupported_reloc_local(object, r_type);
1035 break;
1036
1037 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1038 break;
1039
1040 case elfcpp::R_386_TLS_IE: // Initial-exec
1041 case elfcpp::R_386_TLS_IE_32:
1042 case elfcpp::R_386_TLS_GOTIE:
1043 layout->set_has_static_tls();
1044 if (optimized_type == tls::TLSOPT_NONE)
1045 {
1046 // For the R_386_TLS_IE relocation, we need to create a
1047 // dynamic relocation when building a shared library.
1048 if (r_type == elfcpp::R_386_TLS_IE
1049 && parameters->options().shared())
1050 {
1051 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1052 unsigned int r_sym
1053 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1054 rel_dyn->add_local_relative(object, r_sym,
1055 elfcpp::R_386_RELATIVE,
1056 output_section, data_shndx,
1057 reloc.get_r_offset());
1058 }
1059 // Create a GOT entry for the tp-relative offset.
1060 Output_data_got<32, false>* got
1061 = target->got_section(symtab, layout);
1062 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1063 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1064 ? elfcpp::R_386_TLS_TPOFF32
1065 : elfcpp::R_386_TLS_TPOFF);
1066 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1067 ? GOT_TYPE_TLS_OFFSET
1068 : GOT_TYPE_TLS_NOFFSET);
1069 got->add_local_with_rel(object, r_sym, got_type,
1070 target->rel_dyn_section(layout),
1071 dyn_r_type);
1072 }
1073 else if (optimized_type != tls::TLSOPT_TO_LE)
1074 unsupported_reloc_local(object, r_type);
1075 break;
1076
1077 case elfcpp::R_386_TLS_LE: // Local-exec
1078 case elfcpp::R_386_TLS_LE_32:
1079 layout->set_has_static_tls();
1080 if (output_is_shared)
1081 {
1082 // We need to create a dynamic relocation.
1083 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1084 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1085 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1086 ? elfcpp::R_386_TLS_TPOFF32
1087 : elfcpp::R_386_TLS_TPOFF);
1088 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1089 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1090 data_shndx, reloc.get_r_offset());
1091 }
1092 break;
1093
1094 default:
1095 gold_unreachable();
1096 }
1097 }
1098 break;
1099
1100 case elfcpp::R_386_32PLT:
1101 case elfcpp::R_386_TLS_GD_32:
1102 case elfcpp::R_386_TLS_GD_PUSH:
1103 case elfcpp::R_386_TLS_GD_CALL:
1104 case elfcpp::R_386_TLS_GD_POP:
1105 case elfcpp::R_386_TLS_LDM_32:
1106 case elfcpp::R_386_TLS_LDM_PUSH:
1107 case elfcpp::R_386_TLS_LDM_CALL:
1108 case elfcpp::R_386_TLS_LDM_POP:
1109 case elfcpp::R_386_USED_BY_INTEL_200:
1110 default:
1111 unsupported_reloc_local(object, r_type);
1112 break;
1113 }
1114 }
1115
1116 // Report an unsupported relocation against a global symbol.
1117
1118 void
1119 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1120 unsigned int r_type,
1121 Symbol* gsym)
1122 {
1123 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1124 object->name().c_str(), r_type, gsym->demangled_name().c_str());
1125 }
1126
1127 // Scan a relocation for a global symbol.
1128
1129 inline void
1130 Target_i386::Scan::global(const General_options&,
1131 Symbol_table* symtab,
1132 Layout* layout,
1133 Target_i386* target,
1134 Sized_relobj<32, false>* object,
1135 unsigned int data_shndx,
1136 Output_section* output_section,
1137 const elfcpp::Rel<32, false>& reloc,
1138 unsigned int r_type,
1139 Symbol* gsym)
1140 {
1141 switch (r_type)
1142 {
1143 case elfcpp::R_386_NONE:
1144 case elfcpp::R_386_GNU_VTINHERIT:
1145 case elfcpp::R_386_GNU_VTENTRY:
1146 break;
1147
1148 case elfcpp::R_386_32:
1149 case elfcpp::R_386_16:
1150 case elfcpp::R_386_8:
1151 {
1152 // Make a PLT entry if necessary.
1153 if (gsym->needs_plt_entry())
1154 {
1155 target->make_plt_entry(symtab, layout, gsym);
1156 // Since this is not a PC-relative relocation, we may be
1157 // taking the address of a function. In that case we need to
1158 // set the entry in the dynamic symbol table to the address of
1159 // the PLT entry.
1160 if (gsym->is_from_dynobj() && !parameters->options().shared())
1161 gsym->set_needs_dynsym_value();
1162 }
1163 // Make a dynamic relocation if necessary.
1164 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1165 {
1166 if (target->may_need_copy_reloc(gsym))
1167 {
1168 target->copy_reloc(symtab, layout, object,
1169 data_shndx, output_section, gsym, reloc);
1170 }
1171 else if (r_type == elfcpp::R_386_32
1172 && gsym->can_use_relative_reloc(false))
1173 {
1174 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1175 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1176 output_section, object,
1177 data_shndx, reloc.get_r_offset());
1178 }
1179 else
1180 {
1181 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1182 rel_dyn->add_global(gsym, r_type, output_section, object,
1183 data_shndx, reloc.get_r_offset());
1184 }
1185 }
1186 }
1187 break;
1188
1189 case elfcpp::R_386_PC32:
1190 case elfcpp::R_386_PC16:
1191 case elfcpp::R_386_PC8:
1192 {
1193 // Make a PLT entry if necessary.
1194 if (gsym->needs_plt_entry())
1195 {
1196 // These relocations are used for function calls only in
1197 // non-PIC code. For a 32-bit relocation in a shared library,
1198 // we'll need a text relocation anyway, so we can skip the
1199 // PLT entry and let the dynamic linker bind the call directly
1200 // to the target. For smaller relocations, we should use a
1201 // PLT entry to ensure that the call can reach.
1202 if (!parameters->options().shared()
1203 || r_type != elfcpp::R_386_PC32)
1204 target->make_plt_entry(symtab, layout, gsym);
1205 }
1206 // Make a dynamic relocation if necessary.
1207 int flags = Symbol::NON_PIC_REF;
1208 if (gsym->type() == elfcpp::STT_FUNC)
1209 flags |= Symbol::FUNCTION_CALL;
1210 if (gsym->needs_dynamic_reloc(flags))
1211 {
1212 if (target->may_need_copy_reloc(gsym))
1213 {
1214 target->copy_reloc(symtab, layout, object,
1215 data_shndx, output_section, gsym, reloc);
1216 }
1217 else
1218 {
1219 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1220 rel_dyn->add_global(gsym, r_type, output_section, object,
1221 data_shndx, reloc.get_r_offset());
1222 }
1223 }
1224 }
1225 break;
1226
1227 case elfcpp::R_386_GOT32:
1228 {
1229 // The symbol requires a GOT entry.
1230 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1231 if (gsym->final_value_is_known())
1232 got->add_global(gsym, GOT_TYPE_STANDARD);
1233 else
1234 {
1235 // If this symbol is not fully resolved, we need to add a
1236 // GOT entry with a dynamic relocation.
1237 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1238 if (gsym->is_from_dynobj()
1239 || gsym->is_undefined()
1240 || gsym->is_preemptible())
1241 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1242 rel_dyn, elfcpp::R_386_GLOB_DAT);
1243 else
1244 {
1245 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1246 rel_dyn->add_global_relative(
1247 gsym, elfcpp::R_386_RELATIVE, got,
1248 gsym->got_offset(GOT_TYPE_STANDARD));
1249 }
1250 }
1251 }
1252 break;
1253
1254 case elfcpp::R_386_PLT32:
1255 // If the symbol is fully resolved, this is just a PC32 reloc.
1256 // Otherwise we need a PLT entry.
1257 if (gsym->final_value_is_known())
1258 break;
1259 // If building a shared library, we can also skip the PLT entry
1260 // if the symbol is defined in the output file and is protected
1261 // or hidden.
1262 if (gsym->is_defined()
1263 && !gsym->is_from_dynobj()
1264 && !gsym->is_preemptible())
1265 break;
1266 target->make_plt_entry(symtab, layout, gsym);
1267 break;
1268
1269 case elfcpp::R_386_GOTOFF:
1270 case elfcpp::R_386_GOTPC:
1271 // We need a GOT section.
1272 target->got_section(symtab, layout);
1273 break;
1274
1275 // These are relocations which should only be seen by the
1276 // dynamic linker, and should never be seen here.
1277 case elfcpp::R_386_COPY:
1278 case elfcpp::R_386_GLOB_DAT:
1279 case elfcpp::R_386_JUMP_SLOT:
1280 case elfcpp::R_386_RELATIVE:
1281 case elfcpp::R_386_TLS_TPOFF:
1282 case elfcpp::R_386_TLS_DTPMOD32:
1283 case elfcpp::R_386_TLS_DTPOFF32:
1284 case elfcpp::R_386_TLS_TPOFF32:
1285 case elfcpp::R_386_TLS_DESC:
1286 gold_error(_("%s: unexpected reloc %u in object file"),
1287 object->name().c_str(), r_type);
1288 break;
1289
1290 // These are initial tls relocs, which are expected when
1291 // linking.
1292 case elfcpp::R_386_TLS_GD: // Global-dynamic
1293 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1294 case elfcpp::R_386_TLS_DESC_CALL:
1295 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1296 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1297 case elfcpp::R_386_TLS_IE: // Initial-exec
1298 case elfcpp::R_386_TLS_IE_32:
1299 case elfcpp::R_386_TLS_GOTIE:
1300 case elfcpp::R_386_TLS_LE: // Local-exec
1301 case elfcpp::R_386_TLS_LE_32:
1302 {
1303 const bool is_final = gsym->final_value_is_known();
1304 const tls::Tls_optimization optimized_type
1305 = Target_i386::optimize_tls_reloc(is_final, r_type);
1306 switch (r_type)
1307 {
1308 case elfcpp::R_386_TLS_GD: // Global-dynamic
1309 if (optimized_type == tls::TLSOPT_NONE)
1310 {
1311 // Create a pair of GOT entries for the module index and
1312 // dtv-relative offset.
1313 Output_data_got<32, false>* got
1314 = target->got_section(symtab, layout);
1315 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1316 target->rel_dyn_section(layout),
1317 elfcpp::R_386_TLS_DTPMOD32,
1318 elfcpp::R_386_TLS_DTPOFF32);
1319 }
1320 else if (optimized_type == tls::TLSOPT_TO_IE)
1321 {
1322 // Create a GOT entry for the tp-relative offset.
1323 Output_data_got<32, false>* got
1324 = target->got_section(symtab, layout);
1325 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1326 target->rel_dyn_section(layout),
1327 elfcpp::R_386_TLS_TPOFF);
1328 }
1329 else if (optimized_type != tls::TLSOPT_TO_LE)
1330 unsupported_reloc_global(object, r_type, gsym);
1331 break;
1332
1333 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
1334 target->define_tls_base_symbol(symtab, layout);
1335 if (optimized_type == tls::TLSOPT_NONE)
1336 {
1337 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1338 Output_data_got<32, false>* got
1339 = target->got_section(symtab, layout);
1340 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
1341 target->rel_dyn_section(layout),
1342 elfcpp::R_386_TLS_DESC, 0);
1343 }
1344 else if (optimized_type == tls::TLSOPT_TO_IE)
1345 {
1346 // Create a GOT entry for the tp-relative offset.
1347 Output_data_got<32, false>* got
1348 = target->got_section(symtab, layout);
1349 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1350 target->rel_dyn_section(layout),
1351 elfcpp::R_386_TLS_TPOFF);
1352 }
1353 else if (optimized_type != tls::TLSOPT_TO_LE)
1354 unsupported_reloc_global(object, r_type, gsym);
1355 break;
1356
1357 case elfcpp::R_386_TLS_DESC_CALL:
1358 break;
1359
1360 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1361 if (optimized_type == tls::TLSOPT_NONE)
1362 {
1363 // Create a GOT entry for the module index.
1364 target->got_mod_index_entry(symtab, layout, object);
1365 }
1366 else if (optimized_type != tls::TLSOPT_TO_LE)
1367 unsupported_reloc_global(object, r_type, gsym);
1368 break;
1369
1370 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1371 break;
1372
1373 case elfcpp::R_386_TLS_IE: // Initial-exec
1374 case elfcpp::R_386_TLS_IE_32:
1375 case elfcpp::R_386_TLS_GOTIE:
1376 layout->set_has_static_tls();
1377 if (optimized_type == tls::TLSOPT_NONE)
1378 {
1379 // For the R_386_TLS_IE relocation, we need to create a
1380 // dynamic relocation when building a shared library.
1381 if (r_type == elfcpp::R_386_TLS_IE
1382 && parameters->options().shared())
1383 {
1384 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1385 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1386 output_section, object,
1387 data_shndx,
1388 reloc.get_r_offset());
1389 }
1390 // Create a GOT entry for the tp-relative offset.
1391 Output_data_got<32, false>* got
1392 = target->got_section(symtab, layout);
1393 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1394 ? elfcpp::R_386_TLS_TPOFF32
1395 : elfcpp::R_386_TLS_TPOFF);
1396 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1397 ? GOT_TYPE_TLS_OFFSET
1398 : GOT_TYPE_TLS_NOFFSET);
1399 got->add_global_with_rel(gsym, got_type,
1400 target->rel_dyn_section(layout),
1401 dyn_r_type);
1402 }
1403 else if (optimized_type != tls::TLSOPT_TO_LE)
1404 unsupported_reloc_global(object, r_type, gsym);
1405 break;
1406
1407 case elfcpp::R_386_TLS_LE: // Local-exec
1408 case elfcpp::R_386_TLS_LE_32:
1409 layout->set_has_static_tls();
1410 if (parameters->options().shared())
1411 {
1412 // We need to create a dynamic relocation.
1413 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1414 ? elfcpp::R_386_TLS_TPOFF32
1415 : elfcpp::R_386_TLS_TPOFF);
1416 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1417 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1418 data_shndx, reloc.get_r_offset());
1419 }
1420 break;
1421
1422 default:
1423 gold_unreachable();
1424 }
1425 }
1426 break;
1427
1428 case elfcpp::R_386_32PLT:
1429 case elfcpp::R_386_TLS_GD_32:
1430 case elfcpp::R_386_TLS_GD_PUSH:
1431 case elfcpp::R_386_TLS_GD_CALL:
1432 case elfcpp::R_386_TLS_GD_POP:
1433 case elfcpp::R_386_TLS_LDM_32:
1434 case elfcpp::R_386_TLS_LDM_PUSH:
1435 case elfcpp::R_386_TLS_LDM_CALL:
1436 case elfcpp::R_386_TLS_LDM_POP:
1437 case elfcpp::R_386_USED_BY_INTEL_200:
1438 default:
1439 unsupported_reloc_global(object, r_type, gsym);
1440 break;
1441 }
1442 }
1443
1444 // Scan relocations for a section.
1445
1446 void
1447 Target_i386::scan_relocs(const General_options& options,
1448 Symbol_table* symtab,
1449 Layout* layout,
1450 Sized_relobj<32, false>* object,
1451 unsigned int data_shndx,
1452 unsigned int sh_type,
1453 const unsigned char* prelocs,
1454 size_t reloc_count,
1455 Output_section* output_section,
1456 bool needs_special_offset_handling,
1457 size_t local_symbol_count,
1458 const unsigned char* plocal_symbols)
1459 {
1460 if (sh_type == elfcpp::SHT_RELA)
1461 {
1462 gold_error(_("%s: unsupported RELA reloc section"),
1463 object->name().c_str());
1464 return;
1465 }
1466
1467 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1468 Target_i386::Scan>(
1469 options,
1470 symtab,
1471 layout,
1472 this,
1473 object,
1474 data_shndx,
1475 prelocs,
1476 reloc_count,
1477 output_section,
1478 needs_special_offset_handling,
1479 local_symbol_count,
1480 plocal_symbols);
1481 }
1482
1483 // Finalize the sections.
1484
1485 void
1486 Target_i386::do_finalize_sections(Layout* layout)
1487 {
1488 // Fill in some more dynamic tags.
1489 Output_data_dynamic* const odyn = layout->dynamic_data();
1490 if (odyn != NULL)
1491 {
1492 if (this->got_plt_ != NULL)
1493 odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1494
1495 if (this->plt_ != NULL)
1496 {
1497 const Output_data* od = this->plt_->rel_plt();
1498 odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1499 odyn->add_section_address(elfcpp::DT_JMPREL, od);
1500 odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1501 }
1502
1503 if (this->rel_dyn_ != NULL)
1504 {
1505 const Output_data* od = this->rel_dyn_;
1506 odyn->add_section_address(elfcpp::DT_REL, od);
1507 odyn->add_section_size(elfcpp::DT_RELSZ, od);
1508 odyn->add_constant(elfcpp::DT_RELENT,
1509 elfcpp::Elf_sizes<32>::rel_size);
1510 }
1511
1512 if (!parameters->options().shared())
1513 {
1514 // The value of the DT_DEBUG tag is filled in by the dynamic
1515 // linker at run time, and used by the debugger.
1516 odyn->add_constant(elfcpp::DT_DEBUG, 0);
1517 }
1518 }
1519
1520 // Emit any relocs we saved in an attempt to avoid generating COPY
1521 // relocs.
1522 if (this->copy_relocs_.any_saved_relocs())
1523 this->copy_relocs_.emit(this->rel_dyn_section(layout));
1524 }
1525
1526 // Return whether a direct absolute static relocation needs to be applied.
1527 // In cases where Scan::local() or Scan::global() has created
1528 // a dynamic relocation other than R_386_RELATIVE, the addend
1529 // of the relocation is carried in the data, and we must not
1530 // apply the static relocation.
1531
1532 inline bool
1533 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1534 int ref_flags,
1535 bool is_32bit)
1536 {
1537 // For local symbols, we will have created a non-RELATIVE dynamic
1538 // relocation only if (a) the output is position independent,
1539 // (b) the relocation is absolute (not pc- or segment-relative), and
1540 // (c) the relocation is not 32 bits wide.
1541 if (gsym == NULL)
1542 return !(parameters->options().output_is_position_independent()
1543 && (ref_flags & Symbol::ABSOLUTE_REF)
1544 && !is_32bit);
1545
1546 // For global symbols, we use the same helper routines used in the
1547 // scan pass. If we did not create a dynamic relocation, or if we
1548 // created a RELATIVE dynamic relocation, we should apply the static
1549 // relocation.
1550 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1551 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1552 && gsym->can_use_relative_reloc(ref_flags
1553 & Symbol::FUNCTION_CALL);
1554 return !has_dyn || is_rel;
1555 }
1556
1557 // Perform a relocation.
1558
1559 inline bool
1560 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1561 Target_i386* target,
1562 size_t relnum,
1563 const elfcpp::Rel<32, false>& rel,
1564 unsigned int r_type,
1565 const Sized_symbol<32>* gsym,
1566 const Symbol_value<32>* psymval,
1567 unsigned char* view,
1568 elfcpp::Elf_types<32>::Elf_Addr address,
1569 section_size_type view_size)
1570 {
1571 if (this->skip_call_tls_get_addr_)
1572 {
1573 if (r_type != elfcpp::R_386_PLT32
1574 || gsym == NULL
1575 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1576 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1577 _("missing expected TLS relocation"));
1578 else
1579 {
1580 this->skip_call_tls_get_addr_ = false;
1581 return false;
1582 }
1583 }
1584
1585 // Pick the value to use for symbols defined in shared objects.
1586 Symbol_value<32> symval;
1587 bool is_nonpic = (r_type == elfcpp::R_386_PC8
1588 || r_type == elfcpp::R_386_PC16
1589 || r_type == elfcpp::R_386_PC32);
1590 if (gsym != NULL
1591 && (gsym->is_from_dynobj()
1592 || (parameters->options().shared()
1593 && (gsym->is_undefined() || gsym->is_preemptible())))
1594 && gsym->has_plt_offset()
1595 && (!is_nonpic || !parameters->options().shared()))
1596 {
1597 symval.set_output_value(target->plt_section()->address()
1598 + gsym->plt_offset());
1599 psymval = &symval;
1600 }
1601
1602 const Sized_relobj<32, false>* object = relinfo->object;
1603
1604 // Get the GOT offset if needed.
1605 // The GOT pointer points to the end of the GOT section.
1606 // We need to subtract the size of the GOT section to get
1607 // the actual offset to use in the relocation.
1608 bool have_got_offset = false;
1609 unsigned int got_offset = 0;
1610 switch (r_type)
1611 {
1612 case elfcpp::R_386_GOT32:
1613 if (gsym != NULL)
1614 {
1615 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1616 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1617 - target->got_size());
1618 }
1619 else
1620 {
1621 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1622 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1623 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1624 - target->got_size());
1625 }
1626 have_got_offset = true;
1627 break;
1628
1629 default:
1630 break;
1631 }
1632
1633 switch (r_type)
1634 {
1635 case elfcpp::R_386_NONE:
1636 case elfcpp::R_386_GNU_VTINHERIT:
1637 case elfcpp::R_386_GNU_VTENTRY:
1638 break;
1639
1640 case elfcpp::R_386_32:
1641 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true))
1642 Relocate_functions<32, false>::rel32(view, object, psymval);
1643 break;
1644
1645 case elfcpp::R_386_PC32:
1646 {
1647 int ref_flags = Symbol::NON_PIC_REF;
1648 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1649 ref_flags |= Symbol::FUNCTION_CALL;
1650 if (should_apply_static_reloc(gsym, ref_flags, true))
1651 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1652 }
1653 break;
1654
1655 case elfcpp::R_386_16:
1656 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
1657 Relocate_functions<32, false>::rel16(view, object, psymval);
1658 break;
1659
1660 case elfcpp::R_386_PC16:
1661 {
1662 int ref_flags = Symbol::NON_PIC_REF;
1663 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1664 ref_flags |= Symbol::FUNCTION_CALL;
1665 if (should_apply_static_reloc(gsym, ref_flags, false))
1666 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1667 }
1668 break;
1669
1670 case elfcpp::R_386_8:
1671 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
1672 Relocate_functions<32, false>::rel8(view, object, psymval);
1673 break;
1674
1675 case elfcpp::R_386_PC8:
1676 {
1677 int ref_flags = Symbol::NON_PIC_REF;
1678 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1679 ref_flags |= Symbol::FUNCTION_CALL;
1680 if (should_apply_static_reloc(gsym, ref_flags, false))
1681 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1682 }
1683 break;
1684
1685 case elfcpp::R_386_PLT32:
1686 gold_assert(gsym == NULL
1687 || gsym->has_plt_offset()
1688 || gsym->final_value_is_known()
1689 || (gsym->is_defined()
1690 && !gsym->is_from_dynobj()
1691 && !gsym->is_preemptible()));
1692 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1693 break;
1694
1695 case elfcpp::R_386_GOT32:
1696 gold_assert(have_got_offset);
1697 Relocate_functions<32, false>::rel32(view, got_offset);
1698 break;
1699
1700 case elfcpp::R_386_GOTOFF:
1701 {
1702 elfcpp::Elf_types<32>::Elf_Addr value;
1703 value = (psymval->value(object, 0)
1704 - target->got_plt_section()->address());
1705 Relocate_functions<32, false>::rel32(view, value);
1706 }
1707 break;
1708
1709 case elfcpp::R_386_GOTPC:
1710 {
1711 elfcpp::Elf_types<32>::Elf_Addr value;
1712 value = target->got_plt_section()->address();
1713 Relocate_functions<32, false>::pcrel32(view, value, address);
1714 }
1715 break;
1716
1717 case elfcpp::R_386_COPY:
1718 case elfcpp::R_386_GLOB_DAT:
1719 case elfcpp::R_386_JUMP_SLOT:
1720 case elfcpp::R_386_RELATIVE:
1721 // These are outstanding tls relocs, which are unexpected when
1722 // linking.
1723 case elfcpp::R_386_TLS_TPOFF:
1724 case elfcpp::R_386_TLS_DTPMOD32:
1725 case elfcpp::R_386_TLS_DTPOFF32:
1726 case elfcpp::R_386_TLS_TPOFF32:
1727 case elfcpp::R_386_TLS_DESC:
1728 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1729 _("unexpected reloc %u in object file"),
1730 r_type);
1731 break;
1732
1733 // These are initial tls relocs, which are expected when
1734 // linking.
1735 case elfcpp::R_386_TLS_GD: // Global-dynamic
1736 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1737 case elfcpp::R_386_TLS_DESC_CALL:
1738 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1739 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
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 case elfcpp::R_386_TLS_LE: // Local-exec
1744 case elfcpp::R_386_TLS_LE_32:
1745 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1746 view, address, view_size);
1747 break;
1748
1749 case elfcpp::R_386_32PLT:
1750 case elfcpp::R_386_TLS_GD_32:
1751 case elfcpp::R_386_TLS_GD_PUSH:
1752 case elfcpp::R_386_TLS_GD_CALL:
1753 case elfcpp::R_386_TLS_GD_POP:
1754 case elfcpp::R_386_TLS_LDM_32:
1755 case elfcpp::R_386_TLS_LDM_PUSH:
1756 case elfcpp::R_386_TLS_LDM_CALL:
1757 case elfcpp::R_386_TLS_LDM_POP:
1758 case elfcpp::R_386_USED_BY_INTEL_200:
1759 default:
1760 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1761 _("unsupported reloc %u"),
1762 r_type);
1763 break;
1764 }
1765
1766 return true;
1767 }
1768
1769 // Perform a TLS relocation.
1770
1771 inline void
1772 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1773 Target_i386* target,
1774 size_t relnum,
1775 const elfcpp::Rel<32, false>& rel,
1776 unsigned int r_type,
1777 const Sized_symbol<32>* gsym,
1778 const Symbol_value<32>* psymval,
1779 unsigned char* view,
1780 elfcpp::Elf_types<32>::Elf_Addr,
1781 section_size_type view_size)
1782 {
1783 Output_segment* tls_segment = relinfo->layout->tls_segment();
1784
1785 const Sized_relobj<32, false>* object = relinfo->object;
1786
1787 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1788
1789 const bool is_final =
1790 (gsym == NULL
1791 ? !parameters->options().output_is_position_independent()
1792 : gsym->final_value_is_known());
1793 const tls::Tls_optimization optimized_type
1794 = Target_i386::optimize_tls_reloc(is_final, r_type);
1795 switch (r_type)
1796 {
1797 case elfcpp::R_386_TLS_GD: // Global-dynamic
1798 if (optimized_type == tls::TLSOPT_TO_LE)
1799 {
1800 gold_assert(tls_segment != NULL);
1801 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1802 rel, r_type, value, view,
1803 view_size);
1804 break;
1805 }
1806 else
1807 {
1808 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1809 ? GOT_TYPE_TLS_NOFFSET
1810 : GOT_TYPE_TLS_PAIR);
1811 unsigned int got_offset;
1812 if (gsym != NULL)
1813 {
1814 gold_assert(gsym->has_got_offset(got_type));
1815 got_offset = gsym->got_offset(got_type) - target->got_size();
1816 }
1817 else
1818 {
1819 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1820 gold_assert(object->local_has_got_offset(r_sym, got_type));
1821 got_offset = (object->local_got_offset(r_sym, got_type)
1822 - target->got_size());
1823 }
1824 if (optimized_type == tls::TLSOPT_TO_IE)
1825 {
1826 gold_assert(tls_segment != NULL);
1827 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1828 got_offset, view, view_size);
1829 break;
1830 }
1831 else if (optimized_type == tls::TLSOPT_NONE)
1832 {
1833 // Relocate the field with the offset of the pair of GOT
1834 // entries.
1835 Relocate_functions<32, false>::rel32(view, got_offset);
1836 break;
1837 }
1838 }
1839 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1840 _("unsupported reloc %u"),
1841 r_type);
1842 break;
1843
1844 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1845 case elfcpp::R_386_TLS_DESC_CALL:
1846 if (optimized_type == tls::TLSOPT_TO_LE)
1847 {
1848 gold_assert(tls_segment != NULL);
1849 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
1850 rel, r_type, value, view,
1851 view_size);
1852 break;
1853 }
1854 else
1855 {
1856 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1857 ? GOT_TYPE_TLS_NOFFSET
1858 : GOT_TYPE_TLS_DESC);
1859 unsigned int got_offset;
1860 if (gsym != NULL)
1861 {
1862 gold_assert(gsym->has_got_offset(got_type));
1863 got_offset = gsym->got_offset(got_type) - target->got_size();
1864 }
1865 else
1866 {
1867 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1868 gold_assert(object->local_has_got_offset(r_sym, got_type));
1869 got_offset = (object->local_got_offset(r_sym, got_type)
1870 - target->got_size());
1871 }
1872 if (optimized_type == tls::TLSOPT_TO_IE)
1873 {
1874 gold_assert(tls_segment != NULL);
1875 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1876 got_offset, view, view_size);
1877 break;
1878 }
1879 else if (optimized_type == tls::TLSOPT_NONE)
1880 {
1881 if (r_type == elfcpp::R_386_TLS_GOTDESC)
1882 {
1883 // Relocate the field with the offset of the pair of GOT
1884 // entries.
1885 Relocate_functions<32, false>::rel32(view, got_offset);
1886 }
1887 break;
1888 }
1889 }
1890 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1891 _("unsupported reloc %u"),
1892 r_type);
1893 break;
1894
1895 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1896 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1897 {
1898 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1899 _("both SUN and GNU model "
1900 "TLS relocations"));
1901 break;
1902 }
1903 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1904 if (optimized_type == tls::TLSOPT_TO_LE)
1905 {
1906 gold_assert(tls_segment != NULL);
1907 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1908 value, view, view_size);
1909 break;
1910 }
1911 else if (optimized_type == tls::TLSOPT_NONE)
1912 {
1913 // Relocate the field with the offset of the GOT entry for
1914 // the module index.
1915 unsigned int got_offset;
1916 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
1917 - target->got_size());
1918 Relocate_functions<32, false>::rel32(view, got_offset);
1919 break;
1920 }
1921 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1922 _("unsupported reloc %u"),
1923 r_type);
1924 break;
1925
1926 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1927 // This reloc can appear in debugging sections, in which case we
1928 // won't see the TLS_LDM reloc. The local_dynamic_type field
1929 // tells us this.
1930 if (optimized_type == tls::TLSOPT_TO_LE)
1931 {
1932 gold_assert(tls_segment != NULL);
1933 value -= tls_segment->memsz();
1934 }
1935 Relocate_functions<32, false>::rel32(view, value);
1936 break;
1937
1938 case elfcpp::R_386_TLS_IE: // Initial-exec
1939 case elfcpp::R_386_TLS_GOTIE:
1940 case elfcpp::R_386_TLS_IE_32:
1941 if (optimized_type == tls::TLSOPT_TO_LE)
1942 {
1943 gold_assert(tls_segment != NULL);
1944 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1945 rel, r_type, value, view,
1946 view_size);
1947 break;
1948 }
1949 else if (optimized_type == tls::TLSOPT_NONE)
1950 {
1951 // Relocate the field with the offset of the GOT entry for
1952 // the tp-relative offset of the symbol.
1953 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1954 ? GOT_TYPE_TLS_OFFSET
1955 : GOT_TYPE_TLS_NOFFSET);
1956 unsigned int got_offset;
1957 if (gsym != NULL)
1958 {
1959 gold_assert(gsym->has_got_offset(got_type));
1960 got_offset = gsym->got_offset(got_type);
1961 }
1962 else
1963 {
1964 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1965 gold_assert(object->local_has_got_offset(r_sym, got_type));
1966 got_offset = object->local_got_offset(r_sym, got_type);
1967 }
1968 // For the R_386_TLS_IE relocation, we need to apply the
1969 // absolute address of the GOT entry.
1970 if (r_type == elfcpp::R_386_TLS_IE)
1971 got_offset += target->got_plt_section()->address();
1972 // All GOT offsets are relative to the end of the GOT.
1973 got_offset -= target->got_size();
1974 Relocate_functions<32, false>::rel32(view, got_offset);
1975 break;
1976 }
1977 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1978 _("unsupported reloc %u"),
1979 r_type);
1980 break;
1981
1982 case elfcpp::R_386_TLS_LE: // Local-exec
1983 // If we're creating a shared library, a dynamic relocation will
1984 // have been created for this location, so do not apply it now.
1985 if (!parameters->options().shared())
1986 {
1987 gold_assert(tls_segment != NULL);
1988 value -= tls_segment->memsz();
1989 Relocate_functions<32, false>::rel32(view, value);
1990 }
1991 break;
1992
1993 case elfcpp::R_386_TLS_LE_32:
1994 // If we're creating a shared library, a dynamic relocation will
1995 // have been created for this location, so do not apply it now.
1996 if (!parameters->options().shared())
1997 {
1998 gold_assert(tls_segment != NULL);
1999 value = tls_segment->memsz() - value;
2000 Relocate_functions<32, false>::rel32(view, value);
2001 }
2002 break;
2003 }
2004 }
2005
2006 // Do a relocation in which we convert a TLS General-Dynamic to a
2007 // Local-Exec.
2008
2009 inline void
2010 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2011 size_t relnum,
2012 Output_segment* tls_segment,
2013 const elfcpp::Rel<32, false>& rel,
2014 unsigned int,
2015 elfcpp::Elf_types<32>::Elf_Addr value,
2016 unsigned char* view,
2017 section_size_type view_size)
2018 {
2019 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2020 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2021 // leal foo(%reg),%eax; call ___tls_get_addr
2022 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2023
2024 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2025 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2026
2027 unsigned char op1 = view[-1];
2028 unsigned char op2 = view[-2];
2029
2030 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2031 op2 == 0x8d || op2 == 0x04);
2032 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2033
2034 int roff = 5;
2035
2036 if (op2 == 0x04)
2037 {
2038 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2039 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2040 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2041 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2042 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2043 }
2044 else
2045 {
2046 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2047 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2048 if (rel.get_r_offset() + 9 < view_size
2049 && view[9] == 0x90)
2050 {
2051 // There is a trailing nop. Use the size byte subl.
2052 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2053 roff = 6;
2054 }
2055 else
2056 {
2057 // Use the five byte subl.
2058 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2059 }
2060 }
2061
2062 value = tls_segment->memsz() - value;
2063 Relocate_functions<32, false>::rel32(view + roff, value);
2064
2065 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2066 // We can skip it.
2067 this->skip_call_tls_get_addr_ = true;
2068 }
2069
2070 // Do a relocation in which we convert a TLS General-Dynamic to an
2071 // Initial-Exec.
2072
2073 inline void
2074 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2075 size_t relnum,
2076 Output_segment*,
2077 const elfcpp::Rel<32, false>& rel,
2078 unsigned int,
2079 elfcpp::Elf_types<32>::Elf_Addr value,
2080 unsigned char* view,
2081 section_size_type view_size)
2082 {
2083 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2084 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2085
2086 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2087 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2088
2089 unsigned char op1 = view[-1];
2090 unsigned char op2 = view[-2];
2091
2092 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2093 op2 == 0x8d || op2 == 0x04);
2094 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2095
2096 int roff = 5;
2097
2098 // FIXME: For now, support only the first (SIB) form.
2099 tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2100
2101 if (op2 == 0x04)
2102 {
2103 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2104 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2105 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2106 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2107 memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2108 }
2109 else
2110 {
2111 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2112 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2113 if (rel.get_r_offset() + 9 < view_size
2114 && view[9] == 0x90)
2115 {
2116 // FIXME: This is not the right instruction sequence.
2117 // There is a trailing nop. Use the size byte subl.
2118 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2119 roff = 6;
2120 }
2121 else
2122 {
2123 // FIXME: This is not the right instruction sequence.
2124 // Use the five byte subl.
2125 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2126 }
2127 }
2128
2129 Relocate_functions<32, false>::rel32(view + roff, value);
2130
2131 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2132 // We can skip it.
2133 this->skip_call_tls_get_addr_ = true;
2134 }
2135
2136 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2137 // General-Dynamic to a Local-Exec.
2138
2139 inline void
2140 Target_i386::Relocate::tls_desc_gd_to_le(
2141 const Relocate_info<32, false>* relinfo,
2142 size_t relnum,
2143 Output_segment* tls_segment,
2144 const elfcpp::Rel<32, false>& rel,
2145 unsigned int r_type,
2146 elfcpp::Elf_types<32>::Elf_Addr value,
2147 unsigned char* view,
2148 section_size_type view_size)
2149 {
2150 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2151 {
2152 // leal foo@TLSDESC(%ebx), %eax
2153 // ==> leal foo@NTPOFF, %eax
2154 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2155 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2156 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2157 view[-2] == 0x8d && view[-1] == 0x83);
2158 view[-1] = 0x05;
2159 value -= tls_segment->memsz();
2160 Relocate_functions<32, false>::rel32(view, value);
2161 }
2162 else
2163 {
2164 // call *foo@TLSCALL(%eax)
2165 // ==> nop; nop
2166 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2167 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2168 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2169 view[0] == 0xff && view[1] == 0x10);
2170 view[0] = 0x66;
2171 view[1] = 0x90;
2172 }
2173 }
2174
2175 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2176 // General-Dynamic to an Initial-Exec.
2177
2178 inline void
2179 Target_i386::Relocate::tls_desc_gd_to_ie(
2180 const Relocate_info<32, false>* relinfo,
2181 size_t relnum,
2182 Output_segment*,
2183 const elfcpp::Rel<32, false>& rel,
2184 unsigned int r_type,
2185 elfcpp::Elf_types<32>::Elf_Addr value,
2186 unsigned char* view,
2187 section_size_type view_size)
2188 {
2189 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2190 {
2191 // leal foo@TLSDESC(%ebx), %eax
2192 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2193 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2194 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2195 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2196 view[-2] == 0x8d && view[-1] == 0x83);
2197 view[-2] = 0x8b;
2198 Relocate_functions<32, false>::rel32(view, value);
2199 }
2200 else
2201 {
2202 // call *foo@TLSCALL(%eax)
2203 // ==> nop; nop
2204 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2205 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2206 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2207 view[0] == 0xff && view[1] == 0x10);
2208 view[0] = 0x66;
2209 view[1] = 0x90;
2210 }
2211 }
2212
2213 // Do a relocation in which we convert a TLS Local-Dynamic to a
2214 // Local-Exec.
2215
2216 inline void
2217 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2218 size_t relnum,
2219 Output_segment*,
2220 const elfcpp::Rel<32, false>& rel,
2221 unsigned int,
2222 elfcpp::Elf_types<32>::Elf_Addr,
2223 unsigned char* view,
2224 section_size_type view_size)
2225 {
2226 // leal foo(%reg), %eax; call ___tls_get_addr
2227 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2228
2229 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2230 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2231
2232 // FIXME: Does this test really always pass?
2233 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2234 view[-2] == 0x8d && view[-1] == 0x83);
2235
2236 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2237
2238 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2239
2240 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2241 // We can skip it.
2242 this->skip_call_tls_get_addr_ = true;
2243 }
2244
2245 // Do a relocation in which we convert a TLS Initial-Exec to a
2246 // Local-Exec.
2247
2248 inline void
2249 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2250 size_t relnum,
2251 Output_segment* tls_segment,
2252 const elfcpp::Rel<32, false>& rel,
2253 unsigned int r_type,
2254 elfcpp::Elf_types<32>::Elf_Addr value,
2255 unsigned char* view,
2256 section_size_type view_size)
2257 {
2258 // We have to actually change the instructions, which means that we
2259 // need to examine the opcodes to figure out which instruction we
2260 // are looking at.
2261 if (r_type == elfcpp::R_386_TLS_IE)
2262 {
2263 // movl %gs:XX,%eax ==> movl $YY,%eax
2264 // movl %gs:XX,%reg ==> movl $YY,%reg
2265 // addl %gs:XX,%reg ==> addl $YY,%reg
2266 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2267 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2268
2269 unsigned char op1 = view[-1];
2270 if (op1 == 0xa1)
2271 {
2272 // movl XX,%eax ==> movl $YY,%eax
2273 view[-1] = 0xb8;
2274 }
2275 else
2276 {
2277 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2278
2279 unsigned char op2 = view[-2];
2280 if (op2 == 0x8b)
2281 {
2282 // movl XX,%reg ==> movl $YY,%reg
2283 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2284 (op1 & 0xc7) == 0x05);
2285 view[-2] = 0xc7;
2286 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2287 }
2288 else if (op2 == 0x03)
2289 {
2290 // addl XX,%reg ==> addl $YY,%reg
2291 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2292 (op1 & 0xc7) == 0x05);
2293 view[-2] = 0x81;
2294 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2295 }
2296 else
2297 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2298 }
2299 }
2300 else
2301 {
2302 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2303 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2304 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2305 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2306 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2307
2308 unsigned char op1 = view[-1];
2309 unsigned char op2 = view[-2];
2310 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2311 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2312 if (op2 == 0x8b)
2313 {
2314 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2315 view[-2] = 0xc7;
2316 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2317 }
2318 else if (op2 == 0x2b)
2319 {
2320 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2321 view[-2] = 0x81;
2322 view[-1] = 0xe8 | ((op1 >> 3) & 7);
2323 }
2324 else if (op2 == 0x03)
2325 {
2326 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2327 view[-2] = 0x81;
2328 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2329 }
2330 else
2331 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2332 }
2333
2334 value = tls_segment->memsz() - value;
2335 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2336 value = - value;
2337
2338 Relocate_functions<32, false>::rel32(view, value);
2339 }
2340
2341 // Relocate section data.
2342
2343 void
2344 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2345 unsigned int sh_type,
2346 const unsigned char* prelocs,
2347 size_t reloc_count,
2348 Output_section* output_section,
2349 bool needs_special_offset_handling,
2350 unsigned char* view,
2351 elfcpp::Elf_types<32>::Elf_Addr address,
2352 section_size_type view_size)
2353 {
2354 gold_assert(sh_type == elfcpp::SHT_REL);
2355
2356 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2357 Target_i386::Relocate>(
2358 relinfo,
2359 this,
2360 prelocs,
2361 reloc_count,
2362 output_section,
2363 needs_special_offset_handling,
2364 view,
2365 address,
2366 view_size);
2367 }
2368
2369 // Return the size of a relocation while scanning during a relocatable
2370 // link.
2371
2372 unsigned int
2373 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2374 unsigned int r_type,
2375 Relobj* object)
2376 {
2377 switch (r_type)
2378 {
2379 case elfcpp::R_386_NONE:
2380 case elfcpp::R_386_GNU_VTINHERIT:
2381 case elfcpp::R_386_GNU_VTENTRY:
2382 case elfcpp::R_386_TLS_GD: // Global-dynamic
2383 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2384 case elfcpp::R_386_TLS_DESC_CALL:
2385 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2386 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2387 case elfcpp::R_386_TLS_IE: // Initial-exec
2388 case elfcpp::R_386_TLS_IE_32:
2389 case elfcpp::R_386_TLS_GOTIE:
2390 case elfcpp::R_386_TLS_LE: // Local-exec
2391 case elfcpp::R_386_TLS_LE_32:
2392 return 0;
2393
2394 case elfcpp::R_386_32:
2395 case elfcpp::R_386_PC32:
2396 case elfcpp::R_386_GOT32:
2397 case elfcpp::R_386_PLT32:
2398 case elfcpp::R_386_GOTOFF:
2399 case elfcpp::R_386_GOTPC:
2400 return 4;
2401
2402 case elfcpp::R_386_16:
2403 case elfcpp::R_386_PC16:
2404 return 2;
2405
2406 case elfcpp::R_386_8:
2407 case elfcpp::R_386_PC8:
2408 return 1;
2409
2410 // These are relocations which should only be seen by the
2411 // dynamic linker, and should never be seen here.
2412 case elfcpp::R_386_COPY:
2413 case elfcpp::R_386_GLOB_DAT:
2414 case elfcpp::R_386_JUMP_SLOT:
2415 case elfcpp::R_386_RELATIVE:
2416 case elfcpp::R_386_TLS_TPOFF:
2417 case elfcpp::R_386_TLS_DTPMOD32:
2418 case elfcpp::R_386_TLS_DTPOFF32:
2419 case elfcpp::R_386_TLS_TPOFF32:
2420 case elfcpp::R_386_TLS_DESC:
2421 object->error(_("unexpected reloc %u in object file"), r_type);
2422 return 0;
2423
2424 case elfcpp::R_386_32PLT:
2425 case elfcpp::R_386_TLS_GD_32:
2426 case elfcpp::R_386_TLS_GD_PUSH:
2427 case elfcpp::R_386_TLS_GD_CALL:
2428 case elfcpp::R_386_TLS_GD_POP:
2429 case elfcpp::R_386_TLS_LDM_32:
2430 case elfcpp::R_386_TLS_LDM_PUSH:
2431 case elfcpp::R_386_TLS_LDM_CALL:
2432 case elfcpp::R_386_TLS_LDM_POP:
2433 case elfcpp::R_386_USED_BY_INTEL_200:
2434 default:
2435 object->error(_("unsupported reloc %u in object file"), r_type);
2436 return 0;
2437 }
2438 }
2439
2440 // Scan the relocs during a relocatable link.
2441
2442 void
2443 Target_i386::scan_relocatable_relocs(const General_options& options,
2444 Symbol_table* symtab,
2445 Layout* layout,
2446 Sized_relobj<32, false>* object,
2447 unsigned int data_shndx,
2448 unsigned int sh_type,
2449 const unsigned char* prelocs,
2450 size_t reloc_count,
2451 Output_section* output_section,
2452 bool needs_special_offset_handling,
2453 size_t local_symbol_count,
2454 const unsigned char* plocal_symbols,
2455 Relocatable_relocs* rr)
2456 {
2457 gold_assert(sh_type == elfcpp::SHT_REL);
2458
2459 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2460 Relocatable_size_for_reloc> Scan_relocatable_relocs;
2461
2462 gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2463 Scan_relocatable_relocs>(
2464 options,
2465 symtab,
2466 layout,
2467 object,
2468 data_shndx,
2469 prelocs,
2470 reloc_count,
2471 output_section,
2472 needs_special_offset_handling,
2473 local_symbol_count,
2474 plocal_symbols,
2475 rr);
2476 }
2477
2478 // Relocate a section during a relocatable link.
2479
2480 void
2481 Target_i386::relocate_for_relocatable(
2482 const Relocate_info<32, false>* relinfo,
2483 unsigned int sh_type,
2484 const unsigned char* prelocs,
2485 size_t reloc_count,
2486 Output_section* output_section,
2487 off_t offset_in_output_section,
2488 const Relocatable_relocs* rr,
2489 unsigned char* view,
2490 elfcpp::Elf_types<32>::Elf_Addr view_address,
2491 section_size_type view_size,
2492 unsigned char* reloc_view,
2493 section_size_type reloc_view_size)
2494 {
2495 gold_assert(sh_type == elfcpp::SHT_REL);
2496
2497 gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2498 relinfo,
2499 prelocs,
2500 reloc_count,
2501 output_section,
2502 offset_in_output_section,
2503 rr,
2504 view,
2505 view_address,
2506 view_size,
2507 reloc_view,
2508 reloc_view_size);
2509 }
2510
2511 // Return the value to use for a dynamic which requires special
2512 // treatment. This is how we support equality comparisons of function
2513 // pointers across shared library boundaries, as described in the
2514 // processor specific ABI supplement.
2515
2516 uint64_t
2517 Target_i386::do_dynsym_value(const Symbol* gsym) const
2518 {
2519 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2520 return this->plt_section()->address() + gsym->plt_offset();
2521 }
2522
2523 // Return a string used to fill a code section with nops to take up
2524 // the specified length.
2525
2526 std::string
2527 Target_i386::do_code_fill(section_size_type length) const
2528 {
2529 if (length >= 16)
2530 {
2531 // Build a jmp instruction to skip over the bytes.
2532 unsigned char jmp[5];
2533 jmp[0] = 0xe9;
2534 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2535 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2536 + std::string(length - 5, '\0'));
2537 }
2538
2539 // Nop sequences of various lengths.
2540 const char nop1[1] = { 0x90 }; // nop
2541 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
2542 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2543 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2544 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2545 0x00 }; // leal 0(%esi,1),%esi
2546 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2547 0x00, 0x00 };
2548 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2549 0x00, 0x00, 0x00 };
2550 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2551 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2552 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2553 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2554 0x00 };
2555 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2556 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2557 0x00, 0x00 };
2558 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2559 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2560 0x00, 0x00, 0x00 };
2561 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2562 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2563 0x00, 0x00, 0x00, 0x00 };
2564 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2565 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2566 0x27, 0x00, 0x00, 0x00,
2567 0x00 };
2568 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2569 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2570 0xbc, 0x27, 0x00, 0x00,
2571 0x00, 0x00 };
2572 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2573 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2574 0x90, 0x90, 0x90, 0x90,
2575 0x90, 0x90, 0x90 };
2576
2577 const char* nops[16] = {
2578 NULL,
2579 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2580 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2581 };
2582
2583 return std::string(nops[length], length);
2584 }
2585
2586 // The selector for i386 object files.
2587
2588 class Target_selector_i386 : public Target_selector
2589 {
2590 public:
2591 Target_selector_i386()
2592 : Target_selector(elfcpp::EM_386, 32, false, "elf32-i386")
2593 { }
2594
2595 Target*
2596 do_instantiate_target()
2597 { return new Target_i386(); }
2598 };
2599
2600 Target_selector_i386 target_selector_i386;
2601
2602 } // End anonymous namespace.
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