* i386.cc (class Target_i386::Relocate): Add ldo_addrs_ field.
[deliverable/binutils-gdb.git] / gold / i386.cc
1 // i386.cc -- i386 target support for gold.
2
3 // Copyright 2006, 2007, 2008, 2009 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 #include "freebsd.h"
41
42 namespace
43 {
44
45 using namespace gold;
46
47 class Output_data_plt_i386;
48
49 // The i386 target class.
50 // TLS info comes from
51 // http://people.redhat.com/drepper/tls.pdf
52 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
53
54 class Target_i386 : public Target_freebsd<32, false>
55 {
56 public:
57 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
58
59 Target_i386()
60 : Target_freebsd<32, false>(&i386_info),
61 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
62 copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
63 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
64 { }
65
66 // Process the relocations to determine unreferenced sections for
67 // garbage collection.
68 void
69 gc_process_relocs(const General_options& options,
70 Symbol_table* symtab,
71 Layout* layout,
72 Sized_relobj<32, false>* object,
73 unsigned int data_shndx,
74 unsigned int sh_type,
75 const unsigned char* prelocs,
76 size_t reloc_count,
77 Output_section* output_section,
78 bool needs_special_offset_handling,
79 size_t local_symbol_count,
80 const unsigned char* plocal_symbols);
81
82 // Scan the relocations to look for symbol adjustments.
83 void
84 scan_relocs(const General_options& options,
85 Symbol_table* symtab,
86 Layout* layout,
87 Sized_relobj<32, false>* object,
88 unsigned int data_shndx,
89 unsigned int sh_type,
90 const unsigned char* prelocs,
91 size_t reloc_count,
92 Output_section* output_section,
93 bool needs_special_offset_handling,
94 size_t local_symbol_count,
95 const unsigned char* plocal_symbols);
96
97 // Finalize the sections.
98 void
99 do_finalize_sections(Layout*);
100
101 // Return the value to use for a dynamic which requires special
102 // treatment.
103 uint64_t
104 do_dynsym_value(const Symbol*) const;
105
106 // Relocate a section.
107 void
108 relocate_section(const Relocate_info<32, false>*,
109 unsigned int sh_type,
110 const unsigned char* prelocs,
111 size_t reloc_count,
112 Output_section* output_section,
113 bool needs_special_offset_handling,
114 unsigned char* view,
115 elfcpp::Elf_types<32>::Elf_Addr view_address,
116 section_size_type view_size);
117
118 // Scan the relocs during a relocatable link.
119 void
120 scan_relocatable_relocs(const General_options& options,
121 Symbol_table* symtab,
122 Layout* layout,
123 Sized_relobj<32, false>* object,
124 unsigned int data_shndx,
125 unsigned int sh_type,
126 const unsigned char* prelocs,
127 size_t reloc_count,
128 Output_section* output_section,
129 bool needs_special_offset_handling,
130 size_t local_symbol_count,
131 const unsigned char* plocal_symbols,
132 Relocatable_relocs*);
133
134 // Relocate a section during a relocatable link.
135 void
136 relocate_for_relocatable(const Relocate_info<32, false>*,
137 unsigned int sh_type,
138 const unsigned char* prelocs,
139 size_t reloc_count,
140 Output_section* output_section,
141 off_t offset_in_output_section,
142 const Relocatable_relocs*,
143 unsigned char* view,
144 elfcpp::Elf_types<32>::Elf_Addr view_address,
145 section_size_type view_size,
146 unsigned char* reloc_view,
147 section_size_type reloc_view_size);
148
149 // Return a string used to fill a code section with nops.
150 std::string
151 do_code_fill(section_size_type length) const;
152
153 // Return whether SYM is defined by the ABI.
154 bool
155 do_is_defined_by_abi(const Symbol* sym) const
156 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
157
158 // Return whether a symbol name implies a local label. The UnixWare
159 // 2.1 cc generates temporary symbols that start with .X, so we
160 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
161 // If so, we should move the .X recognition into
162 // Target::do_is_local_label_name.
163 bool
164 do_is_local_label_name(const char* name) const
165 {
166 if (name[0] == '.' && name[1] == 'X')
167 return true;
168 return Target::do_is_local_label_name(name);
169 }
170
171 // Return the size of the GOT section.
172 section_size_type
173 got_size()
174 {
175 gold_assert(this->got_ != NULL);
176 return this->got_->data_size();
177 }
178
179 private:
180 // The class which scans relocations.
181 struct Scan
182 {
183 inline void
184 local(const General_options& options, Symbol_table* symtab,
185 Layout* layout, Target_i386* target,
186 Sized_relobj<32, false>* object,
187 unsigned int data_shndx,
188 Output_section* output_section,
189 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
190 const elfcpp::Sym<32, false>& lsym);
191
192 inline void
193 global(const General_options& options, Symbol_table* symtab,
194 Layout* layout, Target_i386* target,
195 Sized_relobj<32, false>* object,
196 unsigned int data_shndx,
197 Output_section* output_section,
198 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
199 Symbol* gsym);
200
201 static void
202 unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
203
204 static void
205 unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
206 Symbol*);
207 };
208
209 // The class which implements relocation.
210 class Relocate
211 {
212 public:
213 Relocate()
214 : skip_call_tls_get_addr_(false),
215 local_dynamic_type_(LOCAL_DYNAMIC_NONE), ldo_addrs_()
216 { }
217
218 ~Relocate()
219 {
220 if (this->skip_call_tls_get_addr_)
221 {
222 // FIXME: This needs to specify the location somehow.
223 gold_error(_("missing expected TLS relocation"));
224 }
225 }
226
227 // Return whether the static relocation needs to be applied.
228 inline bool
229 should_apply_static_reloc(const Sized_symbol<32>* gsym,
230 int ref_flags,
231 bool is_32bit,
232 Output_section* output_section);
233
234 // Do a relocation. Return false if the caller should not issue
235 // any warnings about this relocation.
236 inline bool
237 relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
238 size_t relnum, const elfcpp::Rel<32, false>&,
239 unsigned int r_type, const Sized_symbol<32>*,
240 const Symbol_value<32>*,
241 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
242 section_size_type);
243
244 private:
245 // Do a TLS relocation.
246 inline void
247 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
248 size_t relnum, const elfcpp::Rel<32, false>&,
249 unsigned int r_type, const Sized_symbol<32>*,
250 const Symbol_value<32>*,
251 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
252 section_size_type);
253
254 // Do a TLS General-Dynamic to Initial-Exec transition.
255 inline void
256 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
257 Output_segment* tls_segment,
258 const elfcpp::Rel<32, false>&, unsigned int r_type,
259 elfcpp::Elf_types<32>::Elf_Addr value,
260 unsigned char* view,
261 section_size_type view_size);
262
263 // Do a TLS General-Dynamic to Local-Exec transition.
264 inline void
265 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
266 Output_segment* tls_segment,
267 const elfcpp::Rel<32, false>&, unsigned int r_type,
268 elfcpp::Elf_types<32>::Elf_Addr value,
269 unsigned char* view,
270 section_size_type view_size);
271
272 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
273 // transition.
274 inline void
275 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
276 Output_segment* tls_segment,
277 const elfcpp::Rel<32, false>&, unsigned int r_type,
278 elfcpp::Elf_types<32>::Elf_Addr value,
279 unsigned char* view,
280 section_size_type view_size);
281
282 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
283 // transition.
284 inline void
285 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
286 Output_segment* tls_segment,
287 const elfcpp::Rel<32, false>&, unsigned int r_type,
288 elfcpp::Elf_types<32>::Elf_Addr value,
289 unsigned char* view,
290 section_size_type view_size);
291
292 // Do a TLS Local-Dynamic to Local-Exec transition.
293 inline void
294 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
295 Output_segment* tls_segment,
296 const elfcpp::Rel<32, false>&, unsigned int r_type,
297 elfcpp::Elf_types<32>::Elf_Addr value,
298 unsigned char* view,
299 section_size_type view_size);
300
301 // Do a TLS Initial-Exec to Local-Exec transition.
302 static inline void
303 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
304 Output_segment* tls_segment,
305 const elfcpp::Rel<32, false>&, unsigned int r_type,
306 elfcpp::Elf_types<32>::Elf_Addr value,
307 unsigned char* view,
308 section_size_type view_size);
309
310 // Fix up LDO_32 relocations we've already seen.
311 void
312 fix_up_ldo(const Relocate_info<32, false>*);
313
314 // We need to keep track of which type of local dynamic relocation
315 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
316 enum Local_dynamic_type
317 {
318 LOCAL_DYNAMIC_NONE,
319 LOCAL_DYNAMIC_SUN,
320 LOCAL_DYNAMIC_GNU
321 };
322
323 // This is set if we should skip the next reloc, which should be a
324 // PLT32 reloc against ___tls_get_addr.
325 bool skip_call_tls_get_addr_;
326 // The type of local dynamic relocation we have seen in the section
327 // being relocated, if any.
328 Local_dynamic_type local_dynamic_type_;
329 // A list of LDO_32 offsets, in case we find LDM after LDO_32.
330 std::vector<unsigned char*> ldo_addrs_;
331 };
332
333 // A class which returns the size required for a relocation type,
334 // used while scanning relocs during a relocatable link.
335 class Relocatable_size_for_reloc
336 {
337 public:
338 unsigned int
339 get_size_for_reloc(unsigned int, Relobj*);
340 };
341
342 // Adjust TLS relocation type based on the options and whether this
343 // is a local symbol.
344 static tls::Tls_optimization
345 optimize_tls_reloc(bool is_final, int r_type);
346
347 // Get the GOT section, creating it if necessary.
348 Output_data_got<32, false>*
349 got_section(Symbol_table*, Layout*);
350
351 // Get the GOT PLT section.
352 Output_data_space*
353 got_plt_section() const
354 {
355 gold_assert(this->got_plt_ != NULL);
356 return this->got_plt_;
357 }
358
359 // Create a PLT entry for a global symbol.
360 void
361 make_plt_entry(Symbol_table*, Layout*, Symbol*);
362
363 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
364 void
365 define_tls_base_symbol(Symbol_table*, Layout*);
366
367 // Create a GOT entry for the TLS module index.
368 unsigned int
369 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
370 Sized_relobj<32, false>* object);
371
372 // Get the PLT section.
373 const Output_data_plt_i386*
374 plt_section() const
375 {
376 gold_assert(this->plt_ != NULL);
377 return this->plt_;
378 }
379
380 // Get the dynamic reloc section, creating it if necessary.
381 Reloc_section*
382 rel_dyn_section(Layout*);
383
384 // Add a potential copy relocation.
385 void
386 copy_reloc(Symbol_table* symtab, Layout* layout,
387 Sized_relobj<32, false>* object,
388 unsigned int shndx, Output_section* output_section,
389 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
390 {
391 this->copy_relocs_.copy_reloc(symtab, layout,
392 symtab->get_sized_symbol<32>(sym),
393 object, shndx, output_section, reloc,
394 this->rel_dyn_section(layout));
395 }
396
397 // Information about this specific target which we pass to the
398 // general Target structure.
399 static const Target::Target_info i386_info;
400
401 // The types of GOT entries needed for this platform.
402 enum Got_type
403 {
404 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
405 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
406 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
407 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
408 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
409 };
410
411 // The GOT section.
412 Output_data_got<32, false>* got_;
413 // The PLT section.
414 Output_data_plt_i386* plt_;
415 // The GOT PLT section.
416 Output_data_space* got_plt_;
417 // The dynamic reloc section.
418 Reloc_section* rel_dyn_;
419 // Relocs saved to avoid a COPY reloc.
420 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
421 // Space for variables copied with a COPY reloc.
422 Output_data_space* dynbss_;
423 // Offset of the GOT entry for the TLS module index.
424 unsigned int got_mod_index_offset_;
425 // True if the _TLS_MODULE_BASE_ symbol has been defined.
426 bool tls_base_symbol_defined_;
427 };
428
429 const Target::Target_info Target_i386::i386_info =
430 {
431 32, // size
432 false, // is_big_endian
433 elfcpp::EM_386, // machine_code
434 false, // has_make_symbol
435 false, // has_resolve
436 true, // has_code_fill
437 true, // is_default_stack_executable
438 '\0', // wrap_char
439 "/usr/lib/libc.so.1", // dynamic_linker
440 0x08048000, // default_text_segment_address
441 0x1000, // abi_pagesize (overridable by -z max-page-size)
442 0x1000, // common_pagesize (overridable by -z common-page-size)
443 elfcpp::SHN_UNDEF, // small_common_shndx
444 elfcpp::SHN_UNDEF, // large_common_shndx
445 0, // small_common_section_flags
446 0 // large_common_section_flags
447 };
448
449 // Get the GOT section, creating it if necessary.
450
451 Output_data_got<32, false>*
452 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
453 {
454 if (this->got_ == NULL)
455 {
456 gold_assert(symtab != NULL && layout != NULL);
457
458 this->got_ = new Output_data_got<32, false>();
459
460 Output_section* os;
461 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
462 (elfcpp::SHF_ALLOC
463 | elfcpp::SHF_WRITE),
464 this->got_);
465 os->set_is_relro();
466
467 // The old GNU linker creates a .got.plt section. We just
468 // create another set of data in the .got section. Note that we
469 // always create a PLT if we create a GOT, although the PLT
470 // might be empty.
471 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
472 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
473 (elfcpp::SHF_ALLOC
474 | elfcpp::SHF_WRITE),
475 this->got_plt_);
476 os->set_is_relro();
477
478 // The first three entries are reserved.
479 this->got_plt_->set_current_data_size(3 * 4);
480
481 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
482 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
483 this->got_plt_,
484 0, 0, elfcpp::STT_OBJECT,
485 elfcpp::STB_LOCAL,
486 elfcpp::STV_HIDDEN, 0,
487 false, false);
488 }
489
490 return this->got_;
491 }
492
493 // Get the dynamic reloc section, creating it if necessary.
494
495 Target_i386::Reloc_section*
496 Target_i386::rel_dyn_section(Layout* layout)
497 {
498 if (this->rel_dyn_ == NULL)
499 {
500 gold_assert(layout != NULL);
501 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
502 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
503 elfcpp::SHF_ALLOC, this->rel_dyn_);
504 }
505 return this->rel_dyn_;
506 }
507
508 // A class to handle the PLT data.
509
510 class Output_data_plt_i386 : public Output_section_data
511 {
512 public:
513 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
514
515 Output_data_plt_i386(Layout*, Output_data_space*);
516
517 // Add an entry to the PLT.
518 void
519 add_entry(Symbol* gsym);
520
521 // Return the .rel.plt section data.
522 const Reloc_section*
523 rel_plt() const
524 { return this->rel_; }
525
526 protected:
527 void
528 do_adjust_output_section(Output_section* os);
529
530 // Write to a map file.
531 void
532 do_print_to_mapfile(Mapfile* mapfile) const
533 { mapfile->print_output_data(this, _("** PLT")); }
534
535 private:
536 // The size of an entry in the PLT.
537 static const int plt_entry_size = 16;
538
539 // The first entry in the PLT for an executable.
540 static unsigned char exec_first_plt_entry[plt_entry_size];
541
542 // The first entry in the PLT for a shared object.
543 static unsigned char dyn_first_plt_entry[plt_entry_size];
544
545 // Other entries in the PLT for an executable.
546 static unsigned char exec_plt_entry[plt_entry_size];
547
548 // Other entries in the PLT for a shared object.
549 static unsigned char dyn_plt_entry[plt_entry_size];
550
551 // Set the final size.
552 void
553 set_final_data_size()
554 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
555
556 // Write out the PLT data.
557 void
558 do_write(Output_file*);
559
560 // The reloc section.
561 Reloc_section* rel_;
562 // The .got.plt section.
563 Output_data_space* got_plt_;
564 // The number of PLT entries.
565 unsigned int count_;
566 };
567
568 // Create the PLT section. The ordinary .got section is an argument,
569 // since we need to refer to the start. We also create our own .got
570 // section just for PLT entries.
571
572 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
573 Output_data_space* got_plt)
574 : Output_section_data(4), got_plt_(got_plt), count_(0)
575 {
576 this->rel_ = new Reloc_section(false);
577 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
578 elfcpp::SHF_ALLOC, this->rel_);
579 }
580
581 void
582 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
583 {
584 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
585 // linker, and so do we.
586 os->set_entsize(4);
587 }
588
589 // Add an entry to the PLT.
590
591 void
592 Output_data_plt_i386::add_entry(Symbol* gsym)
593 {
594 gold_assert(!gsym->has_plt_offset());
595
596 // Note that when setting the PLT offset we skip the initial
597 // reserved PLT entry.
598 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
599
600 ++this->count_;
601
602 section_offset_type got_offset = this->got_plt_->current_data_size();
603
604 // Every PLT entry needs a GOT entry which points back to the PLT
605 // entry (this will be changed by the dynamic linker, normally
606 // lazily when the function is called).
607 this->got_plt_->set_current_data_size(got_offset + 4);
608
609 // Every PLT entry needs a reloc.
610 gsym->set_needs_dynsym_entry();
611 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
612 got_offset);
613
614 // Note that we don't need to save the symbol. The contents of the
615 // PLT are independent of which symbols are used. The symbols only
616 // appear in the relocations.
617 }
618
619 // The first entry in the PLT for an executable.
620
621 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
622 {
623 0xff, 0x35, // pushl contents of memory address
624 0, 0, 0, 0, // replaced with address of .got + 4
625 0xff, 0x25, // jmp indirect
626 0, 0, 0, 0, // replaced with address of .got + 8
627 0, 0, 0, 0 // unused
628 };
629
630 // The first entry in the PLT for a shared object.
631
632 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
633 {
634 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
635 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
636 0, 0, 0, 0 // unused
637 };
638
639 // Subsequent entries in the PLT for an executable.
640
641 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
642 {
643 0xff, 0x25, // jmp indirect
644 0, 0, 0, 0, // replaced with address of symbol in .got
645 0x68, // pushl immediate
646 0, 0, 0, 0, // replaced with offset into relocation table
647 0xe9, // jmp relative
648 0, 0, 0, 0 // replaced with offset to start of .plt
649 };
650
651 // Subsequent entries in the PLT for a shared object.
652
653 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
654 {
655 0xff, 0xa3, // jmp *offset(%ebx)
656 0, 0, 0, 0, // replaced with offset of symbol in .got
657 0x68, // pushl immediate
658 0, 0, 0, 0, // replaced with offset into relocation table
659 0xe9, // jmp relative
660 0, 0, 0, 0 // replaced with offset to start of .plt
661 };
662
663 // Write out the PLT. This uses the hand-coded instructions above,
664 // and adjusts them as needed. This is all specified by the i386 ELF
665 // Processor Supplement.
666
667 void
668 Output_data_plt_i386::do_write(Output_file* of)
669 {
670 const off_t offset = this->offset();
671 const section_size_type oview_size =
672 convert_to_section_size_type(this->data_size());
673 unsigned char* const oview = of->get_output_view(offset, oview_size);
674
675 const off_t got_file_offset = this->got_plt_->offset();
676 const section_size_type got_size =
677 convert_to_section_size_type(this->got_plt_->data_size());
678 unsigned char* const got_view = of->get_output_view(got_file_offset,
679 got_size);
680
681 unsigned char* pov = oview;
682
683 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
684 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
685
686 if (parameters->options().shared())
687 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
688 else
689 {
690 memcpy(pov, exec_first_plt_entry, plt_entry_size);
691 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
692 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
693 }
694 pov += plt_entry_size;
695
696 unsigned char* got_pov = got_view;
697
698 memset(got_pov, 0, 12);
699 got_pov += 12;
700
701 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
702
703 unsigned int plt_offset = plt_entry_size;
704 unsigned int plt_rel_offset = 0;
705 unsigned int got_offset = 12;
706 const unsigned int count = this->count_;
707 for (unsigned int i = 0;
708 i < count;
709 ++i,
710 pov += plt_entry_size,
711 got_pov += 4,
712 plt_offset += plt_entry_size,
713 plt_rel_offset += rel_size,
714 got_offset += 4)
715 {
716 // Set and adjust the PLT entry itself.
717
718 if (parameters->options().shared())
719 {
720 memcpy(pov, dyn_plt_entry, plt_entry_size);
721 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
722 }
723 else
724 {
725 memcpy(pov, exec_plt_entry, plt_entry_size);
726 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
727 (got_address
728 + got_offset));
729 }
730
731 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
732 elfcpp::Swap<32, false>::writeval(pov + 12,
733 - (plt_offset + plt_entry_size));
734
735 // Set the entry in the GOT.
736 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
737 }
738
739 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
740 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
741
742 of->write_output_view(offset, oview_size, oview);
743 of->write_output_view(got_file_offset, got_size, got_view);
744 }
745
746 // Create a PLT entry for a global symbol.
747
748 void
749 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
750 {
751 if (gsym->has_plt_offset())
752 return;
753
754 if (this->plt_ == NULL)
755 {
756 // Create the GOT sections first.
757 this->got_section(symtab, layout);
758
759 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
760 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
761 (elfcpp::SHF_ALLOC
762 | elfcpp::SHF_EXECINSTR),
763 this->plt_);
764 }
765
766 this->plt_->add_entry(gsym);
767 }
768
769 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
770
771 void
772 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
773 {
774 if (this->tls_base_symbol_defined_)
775 return;
776
777 Output_segment* tls_segment = layout->tls_segment();
778 if (tls_segment != NULL)
779 {
780 bool is_exec = parameters->options().output_is_executable();
781 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
782 tls_segment, 0, 0,
783 elfcpp::STT_TLS,
784 elfcpp::STB_LOCAL,
785 elfcpp::STV_HIDDEN, 0,
786 (is_exec
787 ? Symbol::SEGMENT_END
788 : Symbol::SEGMENT_START),
789 true);
790 }
791 this->tls_base_symbol_defined_ = true;
792 }
793
794 // Create a GOT entry for the TLS module index.
795
796 unsigned int
797 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
798 Sized_relobj<32, false>* object)
799 {
800 if (this->got_mod_index_offset_ == -1U)
801 {
802 gold_assert(symtab != NULL && layout != NULL && object != NULL);
803 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
804 Output_data_got<32, false>* got = this->got_section(symtab, layout);
805 unsigned int got_offset = got->add_constant(0);
806 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
807 got_offset);
808 got->add_constant(0);
809 this->got_mod_index_offset_ = got_offset;
810 }
811 return this->got_mod_index_offset_;
812 }
813
814 // Optimize the TLS relocation type based on what we know about the
815 // symbol. IS_FINAL is true if the final address of this symbol is
816 // known at link time.
817
818 tls::Tls_optimization
819 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
820 {
821 // If we are generating a shared library, then we can't do anything
822 // in the linker.
823 if (parameters->options().shared())
824 return tls::TLSOPT_NONE;
825
826 switch (r_type)
827 {
828 case elfcpp::R_386_TLS_GD:
829 case elfcpp::R_386_TLS_GOTDESC:
830 case elfcpp::R_386_TLS_DESC_CALL:
831 // These are General-Dynamic which permits fully general TLS
832 // access. Since we know that we are generating an executable,
833 // we can convert this to Initial-Exec. If we also know that
834 // this is a local symbol, we can further switch to Local-Exec.
835 if (is_final)
836 return tls::TLSOPT_TO_LE;
837 return tls::TLSOPT_TO_IE;
838
839 case elfcpp::R_386_TLS_LDM:
840 // This is Local-Dynamic, which refers to a local symbol in the
841 // dynamic TLS block. Since we know that we generating an
842 // executable, we can switch to Local-Exec.
843 return tls::TLSOPT_TO_LE;
844
845 case elfcpp::R_386_TLS_LDO_32:
846 // Another type of Local-Dynamic relocation.
847 return tls::TLSOPT_TO_LE;
848
849 case elfcpp::R_386_TLS_IE:
850 case elfcpp::R_386_TLS_GOTIE:
851 case elfcpp::R_386_TLS_IE_32:
852 // These are Initial-Exec relocs which get the thread offset
853 // from the GOT. If we know that we are linking against the
854 // local symbol, we can switch to Local-Exec, which links the
855 // thread offset into the instruction.
856 if (is_final)
857 return tls::TLSOPT_TO_LE;
858 return tls::TLSOPT_NONE;
859
860 case elfcpp::R_386_TLS_LE:
861 case elfcpp::R_386_TLS_LE_32:
862 // When we already have Local-Exec, there is nothing further we
863 // can do.
864 return tls::TLSOPT_NONE;
865
866 default:
867 gold_unreachable();
868 }
869 }
870
871 // Report an unsupported relocation against a local symbol.
872
873 void
874 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
875 unsigned int r_type)
876 {
877 gold_error(_("%s: unsupported reloc %u against local symbol"),
878 object->name().c_str(), r_type);
879 }
880
881 // Scan a relocation for a local symbol.
882
883 inline void
884 Target_i386::Scan::local(const General_options&,
885 Symbol_table* symtab,
886 Layout* layout,
887 Target_i386* target,
888 Sized_relobj<32, false>* object,
889 unsigned int data_shndx,
890 Output_section* output_section,
891 const elfcpp::Rel<32, false>& reloc,
892 unsigned int r_type,
893 const elfcpp::Sym<32, false>& lsym)
894 {
895 switch (r_type)
896 {
897 case elfcpp::R_386_NONE:
898 case elfcpp::R_386_GNU_VTINHERIT:
899 case elfcpp::R_386_GNU_VTENTRY:
900 break;
901
902 case elfcpp::R_386_32:
903 // If building a shared library (or a position-independent
904 // executable), we need to create a dynamic relocation for
905 // this location. The relocation applied at link time will
906 // apply the link-time value, so we flag the location with
907 // an R_386_RELATIVE relocation so the dynamic loader can
908 // relocate it easily.
909 if (parameters->options().output_is_position_independent())
910 {
911 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
912 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
913 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
914 output_section, data_shndx,
915 reloc.get_r_offset());
916 }
917 break;
918
919 case elfcpp::R_386_16:
920 case elfcpp::R_386_8:
921 // If building a shared library (or a position-independent
922 // executable), we need to create a dynamic relocation for
923 // this location. Because the addend needs to remain in the
924 // data section, we need to be careful not to apply this
925 // relocation statically.
926 if (parameters->options().output_is_position_independent())
927 {
928 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
929 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
930 if (lsym.get_st_type() != elfcpp::STT_SECTION)
931 rel_dyn->add_local(object, r_sym, r_type, output_section,
932 data_shndx, reloc.get_r_offset());
933 else
934 {
935 gold_assert(lsym.get_st_value() == 0);
936 unsigned int shndx = lsym.get_st_shndx();
937 bool is_ordinary;
938 shndx = object->adjust_sym_shndx(r_sym, shndx,
939 &is_ordinary);
940 if (!is_ordinary)
941 object->error(_("section symbol %u has bad shndx %u"),
942 r_sym, shndx);
943 else
944 rel_dyn->add_local_section(object, shndx,
945 r_type, output_section,
946 data_shndx, reloc.get_r_offset());
947 }
948 }
949 break;
950
951 case elfcpp::R_386_PC32:
952 case elfcpp::R_386_PC16:
953 case elfcpp::R_386_PC8:
954 break;
955
956 case elfcpp::R_386_PLT32:
957 // Since we know this is a local symbol, we can handle this as a
958 // PC32 reloc.
959 break;
960
961 case elfcpp::R_386_GOTOFF:
962 case elfcpp::R_386_GOTPC:
963 // We need a GOT section.
964 target->got_section(symtab, layout);
965 break;
966
967 case elfcpp::R_386_GOT32:
968 {
969 // The symbol requires a GOT entry.
970 Output_data_got<32, false>* got = target->got_section(symtab, layout);
971 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
972 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
973 {
974 // If we are generating a shared object, we need to add a
975 // dynamic RELATIVE relocation for this symbol's GOT entry.
976 if (parameters->options().output_is_position_independent())
977 {
978 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
979 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
980 rel_dyn->add_local_relative(
981 object, r_sym, elfcpp::R_386_RELATIVE, got,
982 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
983 }
984 }
985 }
986 break;
987
988 // These are relocations which should only be seen by the
989 // dynamic linker, and should never be seen here.
990 case elfcpp::R_386_COPY:
991 case elfcpp::R_386_GLOB_DAT:
992 case elfcpp::R_386_JUMP_SLOT:
993 case elfcpp::R_386_RELATIVE:
994 case elfcpp::R_386_TLS_TPOFF:
995 case elfcpp::R_386_TLS_DTPMOD32:
996 case elfcpp::R_386_TLS_DTPOFF32:
997 case elfcpp::R_386_TLS_TPOFF32:
998 case elfcpp::R_386_TLS_DESC:
999 gold_error(_("%s: unexpected reloc %u in object file"),
1000 object->name().c_str(), r_type);
1001 break;
1002
1003 // These are initial TLS relocs, which are expected when
1004 // linking.
1005 case elfcpp::R_386_TLS_GD: // Global-dynamic
1006 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1007 case elfcpp::R_386_TLS_DESC_CALL:
1008 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1009 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1010 case elfcpp::R_386_TLS_IE: // Initial-exec
1011 case elfcpp::R_386_TLS_IE_32:
1012 case elfcpp::R_386_TLS_GOTIE:
1013 case elfcpp::R_386_TLS_LE: // Local-exec
1014 case elfcpp::R_386_TLS_LE_32:
1015 {
1016 bool output_is_shared = parameters->options().shared();
1017 const tls::Tls_optimization optimized_type
1018 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1019 switch (r_type)
1020 {
1021 case elfcpp::R_386_TLS_GD: // Global-dynamic
1022 if (optimized_type == tls::TLSOPT_NONE)
1023 {
1024 // Create a pair of GOT entries for the module index and
1025 // dtv-relative offset.
1026 Output_data_got<32, false>* got
1027 = target->got_section(symtab, layout);
1028 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1029 unsigned int shndx = lsym.get_st_shndx();
1030 bool is_ordinary;
1031 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1032 if (!is_ordinary)
1033 object->error(_("local symbol %u has bad shndx %u"),
1034 r_sym, shndx);
1035 else
1036 got->add_local_pair_with_rel(object, r_sym, shndx,
1037 GOT_TYPE_TLS_PAIR,
1038 target->rel_dyn_section(layout),
1039 elfcpp::R_386_TLS_DTPMOD32, 0);
1040 }
1041 else if (optimized_type != tls::TLSOPT_TO_LE)
1042 unsupported_reloc_local(object, r_type);
1043 break;
1044
1045 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1046 target->define_tls_base_symbol(symtab, layout);
1047 if (optimized_type == tls::TLSOPT_NONE)
1048 {
1049 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1050 Output_data_got<32, false>* got
1051 = target->got_section(symtab, layout);
1052 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1053 unsigned int shndx = lsym.get_st_shndx();
1054 bool is_ordinary;
1055 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1056 if (!is_ordinary)
1057 object->error(_("local symbol %u has bad shndx %u"),
1058 r_sym, shndx);
1059 else
1060 got->add_local_pair_with_rel(object, r_sym, shndx,
1061 GOT_TYPE_TLS_DESC,
1062 target->rel_dyn_section(layout),
1063 elfcpp::R_386_TLS_DESC, 0);
1064 }
1065 else if (optimized_type != tls::TLSOPT_TO_LE)
1066 unsupported_reloc_local(object, r_type);
1067 break;
1068
1069 case elfcpp::R_386_TLS_DESC_CALL:
1070 break;
1071
1072 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1073 if (optimized_type == tls::TLSOPT_NONE)
1074 {
1075 // Create a GOT entry for the module index.
1076 target->got_mod_index_entry(symtab, layout, object);
1077 }
1078 else if (optimized_type != tls::TLSOPT_TO_LE)
1079 unsupported_reloc_local(object, r_type);
1080 break;
1081
1082 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1083 break;
1084
1085 case elfcpp::R_386_TLS_IE: // Initial-exec
1086 case elfcpp::R_386_TLS_IE_32:
1087 case elfcpp::R_386_TLS_GOTIE:
1088 layout->set_has_static_tls();
1089 if (optimized_type == tls::TLSOPT_NONE)
1090 {
1091 // For the R_386_TLS_IE relocation, we need to create a
1092 // dynamic relocation when building a shared library.
1093 if (r_type == elfcpp::R_386_TLS_IE
1094 && parameters->options().shared())
1095 {
1096 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1097 unsigned int r_sym
1098 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1099 rel_dyn->add_local_relative(object, r_sym,
1100 elfcpp::R_386_RELATIVE,
1101 output_section, data_shndx,
1102 reloc.get_r_offset());
1103 }
1104 // Create a GOT entry for the tp-relative offset.
1105 Output_data_got<32, false>* got
1106 = target->got_section(symtab, layout);
1107 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1108 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1109 ? elfcpp::R_386_TLS_TPOFF32
1110 : elfcpp::R_386_TLS_TPOFF);
1111 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1112 ? GOT_TYPE_TLS_OFFSET
1113 : GOT_TYPE_TLS_NOFFSET);
1114 got->add_local_with_rel(object, r_sym, got_type,
1115 target->rel_dyn_section(layout),
1116 dyn_r_type);
1117 }
1118 else if (optimized_type != tls::TLSOPT_TO_LE)
1119 unsupported_reloc_local(object, r_type);
1120 break;
1121
1122 case elfcpp::R_386_TLS_LE: // Local-exec
1123 case elfcpp::R_386_TLS_LE_32:
1124 layout->set_has_static_tls();
1125 if (output_is_shared)
1126 {
1127 // We need to create a dynamic relocation.
1128 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1129 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1130 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1131 ? elfcpp::R_386_TLS_TPOFF32
1132 : elfcpp::R_386_TLS_TPOFF);
1133 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1134 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1135 data_shndx, reloc.get_r_offset());
1136 }
1137 break;
1138
1139 default:
1140 gold_unreachable();
1141 }
1142 }
1143 break;
1144
1145 case elfcpp::R_386_32PLT:
1146 case elfcpp::R_386_TLS_GD_32:
1147 case elfcpp::R_386_TLS_GD_PUSH:
1148 case elfcpp::R_386_TLS_GD_CALL:
1149 case elfcpp::R_386_TLS_GD_POP:
1150 case elfcpp::R_386_TLS_LDM_32:
1151 case elfcpp::R_386_TLS_LDM_PUSH:
1152 case elfcpp::R_386_TLS_LDM_CALL:
1153 case elfcpp::R_386_TLS_LDM_POP:
1154 case elfcpp::R_386_USED_BY_INTEL_200:
1155 default:
1156 unsupported_reloc_local(object, r_type);
1157 break;
1158 }
1159 }
1160
1161 // Report an unsupported relocation against a global symbol.
1162
1163 void
1164 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1165 unsigned int r_type,
1166 Symbol* gsym)
1167 {
1168 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1169 object->name().c_str(), r_type, gsym->demangled_name().c_str());
1170 }
1171
1172 // Scan a relocation for a global symbol.
1173
1174 inline void
1175 Target_i386::Scan::global(const General_options&,
1176 Symbol_table* symtab,
1177 Layout* layout,
1178 Target_i386* target,
1179 Sized_relobj<32, false>* object,
1180 unsigned int data_shndx,
1181 Output_section* output_section,
1182 const elfcpp::Rel<32, false>& reloc,
1183 unsigned int r_type,
1184 Symbol* gsym)
1185 {
1186 switch (r_type)
1187 {
1188 case elfcpp::R_386_NONE:
1189 case elfcpp::R_386_GNU_VTINHERIT:
1190 case elfcpp::R_386_GNU_VTENTRY:
1191 break;
1192
1193 case elfcpp::R_386_32:
1194 case elfcpp::R_386_16:
1195 case elfcpp::R_386_8:
1196 {
1197 // Make a PLT entry if necessary.
1198 if (gsym->needs_plt_entry())
1199 {
1200 target->make_plt_entry(symtab, layout, gsym);
1201 // Since this is not a PC-relative relocation, we may be
1202 // taking the address of a function. In that case we need to
1203 // set the entry in the dynamic symbol table to the address of
1204 // the PLT entry.
1205 if (gsym->is_from_dynobj() && !parameters->options().shared())
1206 gsym->set_needs_dynsym_value();
1207 }
1208 // Make a dynamic relocation if necessary.
1209 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1210 {
1211 if (gsym->may_need_copy_reloc())
1212 {
1213 target->copy_reloc(symtab, layout, object,
1214 data_shndx, output_section, gsym, reloc);
1215 }
1216 else if (r_type == elfcpp::R_386_32
1217 && gsym->can_use_relative_reloc(false))
1218 {
1219 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1220 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1221 output_section, object,
1222 data_shndx, reloc.get_r_offset());
1223 }
1224 else
1225 {
1226 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1227 rel_dyn->add_global(gsym, r_type, output_section, object,
1228 data_shndx, reloc.get_r_offset());
1229 }
1230 }
1231 }
1232 break;
1233
1234 case elfcpp::R_386_PC32:
1235 case elfcpp::R_386_PC16:
1236 case elfcpp::R_386_PC8:
1237 {
1238 // Make a PLT entry if necessary.
1239 if (gsym->needs_plt_entry())
1240 {
1241 // These relocations are used for function calls only in
1242 // non-PIC code. For a 32-bit relocation in a shared library,
1243 // we'll need a text relocation anyway, so we can skip the
1244 // PLT entry and let the dynamic linker bind the call directly
1245 // to the target. For smaller relocations, we should use a
1246 // PLT entry to ensure that the call can reach.
1247 if (!parameters->options().shared()
1248 || r_type != elfcpp::R_386_PC32)
1249 target->make_plt_entry(symtab, layout, gsym);
1250 }
1251 // Make a dynamic relocation if necessary.
1252 int flags = Symbol::NON_PIC_REF;
1253 if (gsym->type() == elfcpp::STT_FUNC)
1254 flags |= Symbol::FUNCTION_CALL;
1255 if (gsym->needs_dynamic_reloc(flags))
1256 {
1257 if (gsym->may_need_copy_reloc())
1258 {
1259 target->copy_reloc(symtab, layout, object,
1260 data_shndx, output_section, gsym, reloc);
1261 }
1262 else
1263 {
1264 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1265 rel_dyn->add_global(gsym, r_type, output_section, object,
1266 data_shndx, reloc.get_r_offset());
1267 }
1268 }
1269 }
1270 break;
1271
1272 case elfcpp::R_386_GOT32:
1273 {
1274 // The symbol requires a GOT entry.
1275 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1276 if (gsym->final_value_is_known())
1277 got->add_global(gsym, GOT_TYPE_STANDARD);
1278 else
1279 {
1280 // If this symbol is not fully resolved, we need to add a
1281 // GOT entry with a dynamic relocation.
1282 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1283 if (gsym->is_from_dynobj()
1284 || gsym->is_undefined()
1285 || gsym->is_preemptible())
1286 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1287 rel_dyn, elfcpp::R_386_GLOB_DAT);
1288 else
1289 {
1290 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1291 rel_dyn->add_global_relative(
1292 gsym, elfcpp::R_386_RELATIVE, got,
1293 gsym->got_offset(GOT_TYPE_STANDARD));
1294 }
1295 }
1296 }
1297 break;
1298
1299 case elfcpp::R_386_PLT32:
1300 // If the symbol is fully resolved, this is just a PC32 reloc.
1301 // Otherwise we need a PLT entry.
1302 if (gsym->final_value_is_known())
1303 break;
1304 // If building a shared library, we can also skip the PLT entry
1305 // if the symbol is defined in the output file and is protected
1306 // or hidden.
1307 if (gsym->is_defined()
1308 && !gsym->is_from_dynobj()
1309 && !gsym->is_preemptible())
1310 break;
1311 target->make_plt_entry(symtab, layout, gsym);
1312 break;
1313
1314 case elfcpp::R_386_GOTOFF:
1315 case elfcpp::R_386_GOTPC:
1316 // We need a GOT section.
1317 target->got_section(symtab, layout);
1318 break;
1319
1320 // These are relocations which should only be seen by the
1321 // dynamic linker, and should never be seen here.
1322 case elfcpp::R_386_COPY:
1323 case elfcpp::R_386_GLOB_DAT:
1324 case elfcpp::R_386_JUMP_SLOT:
1325 case elfcpp::R_386_RELATIVE:
1326 case elfcpp::R_386_TLS_TPOFF:
1327 case elfcpp::R_386_TLS_DTPMOD32:
1328 case elfcpp::R_386_TLS_DTPOFF32:
1329 case elfcpp::R_386_TLS_TPOFF32:
1330 case elfcpp::R_386_TLS_DESC:
1331 gold_error(_("%s: unexpected reloc %u in object file"),
1332 object->name().c_str(), r_type);
1333 break;
1334
1335 // These are initial tls relocs, which are expected when
1336 // linking.
1337 case elfcpp::R_386_TLS_GD: // Global-dynamic
1338 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1339 case elfcpp::R_386_TLS_DESC_CALL:
1340 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1341 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1342 case elfcpp::R_386_TLS_IE: // Initial-exec
1343 case elfcpp::R_386_TLS_IE_32:
1344 case elfcpp::R_386_TLS_GOTIE:
1345 case elfcpp::R_386_TLS_LE: // Local-exec
1346 case elfcpp::R_386_TLS_LE_32:
1347 {
1348 const bool is_final = gsym->final_value_is_known();
1349 const tls::Tls_optimization optimized_type
1350 = Target_i386::optimize_tls_reloc(is_final, r_type);
1351 switch (r_type)
1352 {
1353 case elfcpp::R_386_TLS_GD: // Global-dynamic
1354 if (optimized_type == tls::TLSOPT_NONE)
1355 {
1356 // Create a pair of GOT entries for the module index and
1357 // dtv-relative offset.
1358 Output_data_got<32, false>* got
1359 = target->got_section(symtab, layout);
1360 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1361 target->rel_dyn_section(layout),
1362 elfcpp::R_386_TLS_DTPMOD32,
1363 elfcpp::R_386_TLS_DTPOFF32);
1364 }
1365 else if (optimized_type == tls::TLSOPT_TO_IE)
1366 {
1367 // Create a GOT entry for the tp-relative offset.
1368 Output_data_got<32, false>* got
1369 = target->got_section(symtab, layout);
1370 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1371 target->rel_dyn_section(layout),
1372 elfcpp::R_386_TLS_TPOFF);
1373 }
1374 else if (optimized_type != tls::TLSOPT_TO_LE)
1375 unsupported_reloc_global(object, r_type, gsym);
1376 break;
1377
1378 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
1379 target->define_tls_base_symbol(symtab, layout);
1380 if (optimized_type == tls::TLSOPT_NONE)
1381 {
1382 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1383 Output_data_got<32, false>* got
1384 = target->got_section(symtab, layout);
1385 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
1386 target->rel_dyn_section(layout),
1387 elfcpp::R_386_TLS_DESC, 0);
1388 }
1389 else if (optimized_type == tls::TLSOPT_TO_IE)
1390 {
1391 // Create a GOT entry for the tp-relative offset.
1392 Output_data_got<32, false>* got
1393 = target->got_section(symtab, layout);
1394 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1395 target->rel_dyn_section(layout),
1396 elfcpp::R_386_TLS_TPOFF);
1397 }
1398 else if (optimized_type != tls::TLSOPT_TO_LE)
1399 unsupported_reloc_global(object, r_type, gsym);
1400 break;
1401
1402 case elfcpp::R_386_TLS_DESC_CALL:
1403 break;
1404
1405 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1406 if (optimized_type == tls::TLSOPT_NONE)
1407 {
1408 // Create a GOT entry for the module index.
1409 target->got_mod_index_entry(symtab, layout, object);
1410 }
1411 else if (optimized_type != tls::TLSOPT_TO_LE)
1412 unsupported_reloc_global(object, r_type, gsym);
1413 break;
1414
1415 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1416 break;
1417
1418 case elfcpp::R_386_TLS_IE: // Initial-exec
1419 case elfcpp::R_386_TLS_IE_32:
1420 case elfcpp::R_386_TLS_GOTIE:
1421 layout->set_has_static_tls();
1422 if (optimized_type == tls::TLSOPT_NONE)
1423 {
1424 // For the R_386_TLS_IE relocation, we need to create a
1425 // dynamic relocation when building a shared library.
1426 if (r_type == elfcpp::R_386_TLS_IE
1427 && parameters->options().shared())
1428 {
1429 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1430 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1431 output_section, object,
1432 data_shndx,
1433 reloc.get_r_offset());
1434 }
1435 // Create a GOT entry for the tp-relative offset.
1436 Output_data_got<32, false>* got
1437 = target->got_section(symtab, layout);
1438 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1439 ? elfcpp::R_386_TLS_TPOFF32
1440 : elfcpp::R_386_TLS_TPOFF);
1441 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1442 ? GOT_TYPE_TLS_OFFSET
1443 : GOT_TYPE_TLS_NOFFSET);
1444 got->add_global_with_rel(gsym, got_type,
1445 target->rel_dyn_section(layout),
1446 dyn_r_type);
1447 }
1448 else if (optimized_type != tls::TLSOPT_TO_LE)
1449 unsupported_reloc_global(object, r_type, gsym);
1450 break;
1451
1452 case elfcpp::R_386_TLS_LE: // Local-exec
1453 case elfcpp::R_386_TLS_LE_32:
1454 layout->set_has_static_tls();
1455 if (parameters->options().shared())
1456 {
1457 // We need to create a dynamic relocation.
1458 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1459 ? elfcpp::R_386_TLS_TPOFF32
1460 : elfcpp::R_386_TLS_TPOFF);
1461 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1462 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1463 data_shndx, reloc.get_r_offset());
1464 }
1465 break;
1466
1467 default:
1468 gold_unreachable();
1469 }
1470 }
1471 break;
1472
1473 case elfcpp::R_386_32PLT:
1474 case elfcpp::R_386_TLS_GD_32:
1475 case elfcpp::R_386_TLS_GD_PUSH:
1476 case elfcpp::R_386_TLS_GD_CALL:
1477 case elfcpp::R_386_TLS_GD_POP:
1478 case elfcpp::R_386_TLS_LDM_32:
1479 case elfcpp::R_386_TLS_LDM_PUSH:
1480 case elfcpp::R_386_TLS_LDM_CALL:
1481 case elfcpp::R_386_TLS_LDM_POP:
1482 case elfcpp::R_386_USED_BY_INTEL_200:
1483 default:
1484 unsupported_reloc_global(object, r_type, gsym);
1485 break;
1486 }
1487 }
1488
1489 // Process relocations for gc.
1490
1491 void
1492 Target_i386::gc_process_relocs(const General_options& options,
1493 Symbol_table* symtab,
1494 Layout* layout,
1495 Sized_relobj<32, false>* object,
1496 unsigned int data_shndx,
1497 unsigned int,
1498 const unsigned char* prelocs,
1499 size_t reloc_count,
1500 Output_section* output_section,
1501 bool needs_special_offset_handling,
1502 size_t local_symbol_count,
1503 const unsigned char* plocal_symbols)
1504 {
1505 gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1506 Target_i386::Scan>(
1507 options,
1508 symtab,
1509 layout,
1510 this,
1511 object,
1512 data_shndx,
1513 prelocs,
1514 reloc_count,
1515 output_section,
1516 needs_special_offset_handling,
1517 local_symbol_count,
1518 plocal_symbols);
1519 }
1520
1521 // Scan relocations for a section.
1522
1523 void
1524 Target_i386::scan_relocs(const General_options& options,
1525 Symbol_table* symtab,
1526 Layout* layout,
1527 Sized_relobj<32, false>* object,
1528 unsigned int data_shndx,
1529 unsigned int sh_type,
1530 const unsigned char* prelocs,
1531 size_t reloc_count,
1532 Output_section* output_section,
1533 bool needs_special_offset_handling,
1534 size_t local_symbol_count,
1535 const unsigned char* plocal_symbols)
1536 {
1537 if (sh_type == elfcpp::SHT_RELA)
1538 {
1539 gold_error(_("%s: unsupported RELA reloc section"),
1540 object->name().c_str());
1541 return;
1542 }
1543
1544 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1545 Target_i386::Scan>(
1546 options,
1547 symtab,
1548 layout,
1549 this,
1550 object,
1551 data_shndx,
1552 prelocs,
1553 reloc_count,
1554 output_section,
1555 needs_special_offset_handling,
1556 local_symbol_count,
1557 plocal_symbols);
1558 }
1559
1560 // Finalize the sections.
1561
1562 void
1563 Target_i386::do_finalize_sections(Layout* layout)
1564 {
1565 // Fill in some more dynamic tags.
1566 Output_data_dynamic* const odyn = layout->dynamic_data();
1567 if (odyn != NULL)
1568 {
1569 if (this->got_plt_ != NULL)
1570 odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1571
1572 if (this->plt_ != NULL)
1573 {
1574 const Output_data* od = this->plt_->rel_plt();
1575 odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1576 odyn->add_section_address(elfcpp::DT_JMPREL, od);
1577 odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1578 }
1579
1580 if (this->rel_dyn_ != NULL)
1581 {
1582 const Output_data* od = this->rel_dyn_;
1583 odyn->add_section_address(elfcpp::DT_REL, od);
1584 odyn->add_section_size(elfcpp::DT_RELSZ, od);
1585 odyn->add_constant(elfcpp::DT_RELENT,
1586 elfcpp::Elf_sizes<32>::rel_size);
1587 }
1588
1589 if (!parameters->options().shared())
1590 {
1591 // The value of the DT_DEBUG tag is filled in by the dynamic
1592 // linker at run time, and used by the debugger.
1593 odyn->add_constant(elfcpp::DT_DEBUG, 0);
1594 }
1595 }
1596
1597 // Emit any relocs we saved in an attempt to avoid generating COPY
1598 // relocs.
1599 if (this->copy_relocs_.any_saved_relocs())
1600 this->copy_relocs_.emit(this->rel_dyn_section(layout));
1601 }
1602
1603 // Return whether a direct absolute static relocation needs to be applied.
1604 // In cases where Scan::local() or Scan::global() has created
1605 // a dynamic relocation other than R_386_RELATIVE, the addend
1606 // of the relocation is carried in the data, and we must not
1607 // apply the static relocation.
1608
1609 inline bool
1610 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1611 int ref_flags,
1612 bool is_32bit,
1613 Output_section* output_section)
1614 {
1615 // If the output section is not allocated, then we didn't call
1616 // scan_relocs, we didn't create a dynamic reloc, and we must apply
1617 // the reloc here.
1618 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1619 return true;
1620
1621 // For local symbols, we will have created a non-RELATIVE dynamic
1622 // relocation only if (a) the output is position independent,
1623 // (b) the relocation is absolute (not pc- or segment-relative), and
1624 // (c) the relocation is not 32 bits wide.
1625 if (gsym == NULL)
1626 return !(parameters->options().output_is_position_independent()
1627 && (ref_flags & Symbol::ABSOLUTE_REF)
1628 && !is_32bit);
1629
1630 // For global symbols, we use the same helper routines used in the
1631 // scan pass. If we did not create a dynamic relocation, or if we
1632 // created a RELATIVE dynamic relocation, we should apply the static
1633 // relocation.
1634 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1635 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1636 && gsym->can_use_relative_reloc(ref_flags
1637 & Symbol::FUNCTION_CALL);
1638 return !has_dyn || is_rel;
1639 }
1640
1641 // Perform a relocation.
1642
1643 inline bool
1644 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1645 Target_i386* target,
1646 Output_section *output_section,
1647 size_t relnum,
1648 const elfcpp::Rel<32, false>& rel,
1649 unsigned int r_type,
1650 const Sized_symbol<32>* gsym,
1651 const Symbol_value<32>* psymval,
1652 unsigned char* view,
1653 elfcpp::Elf_types<32>::Elf_Addr address,
1654 section_size_type view_size)
1655 {
1656 if (this->skip_call_tls_get_addr_)
1657 {
1658 if ((r_type != elfcpp::R_386_PLT32
1659 && r_type != elfcpp::R_386_PC32)
1660 || gsym == NULL
1661 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1662 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1663 _("missing expected TLS relocation"));
1664 else
1665 {
1666 this->skip_call_tls_get_addr_ = false;
1667 return false;
1668 }
1669 }
1670
1671 // Pick the value to use for symbols defined in shared objects.
1672 Symbol_value<32> symval;
1673 if (gsym != NULL
1674 && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1675 || r_type == elfcpp::R_386_PC16
1676 || r_type == elfcpp::R_386_PC32))
1677 {
1678 symval.set_output_value(target->plt_section()->address()
1679 + gsym->plt_offset());
1680 psymval = &symval;
1681 }
1682
1683 const Sized_relobj<32, false>* object = relinfo->object;
1684
1685 // Get the GOT offset if needed.
1686 // The GOT pointer points to the end of the GOT section.
1687 // We need to subtract the size of the GOT section to get
1688 // the actual offset to use in the relocation.
1689 bool have_got_offset = false;
1690 unsigned int got_offset = 0;
1691 switch (r_type)
1692 {
1693 case elfcpp::R_386_GOT32:
1694 if (gsym != NULL)
1695 {
1696 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1697 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1698 - target->got_size());
1699 }
1700 else
1701 {
1702 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1703 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1704 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1705 - target->got_size());
1706 }
1707 have_got_offset = true;
1708 break;
1709
1710 default:
1711 break;
1712 }
1713
1714 switch (r_type)
1715 {
1716 case elfcpp::R_386_NONE:
1717 case elfcpp::R_386_GNU_VTINHERIT:
1718 case elfcpp::R_386_GNU_VTENTRY:
1719 break;
1720
1721 case elfcpp::R_386_32:
1722 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1723 output_section))
1724 Relocate_functions<32, false>::rel32(view, object, psymval);
1725 break;
1726
1727 case elfcpp::R_386_PC32:
1728 {
1729 int ref_flags = Symbol::NON_PIC_REF;
1730 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1731 ref_flags |= Symbol::FUNCTION_CALL;
1732 if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1733 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1734 }
1735 break;
1736
1737 case elfcpp::R_386_16:
1738 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1739 output_section))
1740 Relocate_functions<32, false>::rel16(view, object, psymval);
1741 break;
1742
1743 case elfcpp::R_386_PC16:
1744 {
1745 int ref_flags = Symbol::NON_PIC_REF;
1746 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1747 ref_flags |= Symbol::FUNCTION_CALL;
1748 if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1749 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1750 }
1751 break;
1752
1753 case elfcpp::R_386_8:
1754 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1755 output_section))
1756 Relocate_functions<32, false>::rel8(view, object, psymval);
1757 break;
1758
1759 case elfcpp::R_386_PC8:
1760 {
1761 int ref_flags = Symbol::NON_PIC_REF;
1762 if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1763 ref_flags |= Symbol::FUNCTION_CALL;
1764 if (should_apply_static_reloc(gsym, ref_flags, false,
1765 output_section))
1766 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1767 }
1768 break;
1769
1770 case elfcpp::R_386_PLT32:
1771 gold_assert(gsym == NULL
1772 || gsym->has_plt_offset()
1773 || gsym->final_value_is_known()
1774 || (gsym->is_defined()
1775 && !gsym->is_from_dynobj()
1776 && !gsym->is_preemptible()));
1777 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1778 break;
1779
1780 case elfcpp::R_386_GOT32:
1781 gold_assert(have_got_offset);
1782 Relocate_functions<32, false>::rel32(view, got_offset);
1783 break;
1784
1785 case elfcpp::R_386_GOTOFF:
1786 {
1787 elfcpp::Elf_types<32>::Elf_Addr value;
1788 value = (psymval->value(object, 0)
1789 - target->got_plt_section()->address());
1790 Relocate_functions<32, false>::rel32(view, value);
1791 }
1792 break;
1793
1794 case elfcpp::R_386_GOTPC:
1795 {
1796 elfcpp::Elf_types<32>::Elf_Addr value;
1797 value = target->got_plt_section()->address();
1798 Relocate_functions<32, false>::pcrel32(view, value, address);
1799 }
1800 break;
1801
1802 case elfcpp::R_386_COPY:
1803 case elfcpp::R_386_GLOB_DAT:
1804 case elfcpp::R_386_JUMP_SLOT:
1805 case elfcpp::R_386_RELATIVE:
1806 // These are outstanding tls relocs, which are unexpected when
1807 // linking.
1808 case elfcpp::R_386_TLS_TPOFF:
1809 case elfcpp::R_386_TLS_DTPMOD32:
1810 case elfcpp::R_386_TLS_DTPOFF32:
1811 case elfcpp::R_386_TLS_TPOFF32:
1812 case elfcpp::R_386_TLS_DESC:
1813 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1814 _("unexpected reloc %u in object file"),
1815 r_type);
1816 break;
1817
1818 // These are initial tls relocs, which are expected when
1819 // linking.
1820 case elfcpp::R_386_TLS_GD: // Global-dynamic
1821 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1822 case elfcpp::R_386_TLS_DESC_CALL:
1823 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1824 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1825 case elfcpp::R_386_TLS_IE: // Initial-exec
1826 case elfcpp::R_386_TLS_IE_32:
1827 case elfcpp::R_386_TLS_GOTIE:
1828 case elfcpp::R_386_TLS_LE: // Local-exec
1829 case elfcpp::R_386_TLS_LE_32:
1830 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1831 view, address, view_size);
1832 break;
1833
1834 case elfcpp::R_386_32PLT:
1835 case elfcpp::R_386_TLS_GD_32:
1836 case elfcpp::R_386_TLS_GD_PUSH:
1837 case elfcpp::R_386_TLS_GD_CALL:
1838 case elfcpp::R_386_TLS_GD_POP:
1839 case elfcpp::R_386_TLS_LDM_32:
1840 case elfcpp::R_386_TLS_LDM_PUSH:
1841 case elfcpp::R_386_TLS_LDM_CALL:
1842 case elfcpp::R_386_TLS_LDM_POP:
1843 case elfcpp::R_386_USED_BY_INTEL_200:
1844 default:
1845 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1846 _("unsupported reloc %u"),
1847 r_type);
1848 break;
1849 }
1850
1851 return true;
1852 }
1853
1854 // Perform a TLS relocation.
1855
1856 inline void
1857 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1858 Target_i386* target,
1859 size_t relnum,
1860 const elfcpp::Rel<32, false>& rel,
1861 unsigned int r_type,
1862 const Sized_symbol<32>* gsym,
1863 const Symbol_value<32>* psymval,
1864 unsigned char* view,
1865 elfcpp::Elf_types<32>::Elf_Addr,
1866 section_size_type view_size)
1867 {
1868 Output_segment* tls_segment = relinfo->layout->tls_segment();
1869
1870 const Sized_relobj<32, false>* object = relinfo->object;
1871
1872 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1873
1874 const bool is_final =
1875 (gsym == NULL
1876 ? !parameters->options().output_is_position_independent()
1877 : gsym->final_value_is_known());
1878 const tls::Tls_optimization optimized_type
1879 = Target_i386::optimize_tls_reloc(is_final, r_type);
1880 switch (r_type)
1881 {
1882 case elfcpp::R_386_TLS_GD: // Global-dynamic
1883 if (optimized_type == tls::TLSOPT_TO_LE)
1884 {
1885 gold_assert(tls_segment != NULL);
1886 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1887 rel, r_type, value, view,
1888 view_size);
1889 break;
1890 }
1891 else
1892 {
1893 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1894 ? GOT_TYPE_TLS_NOFFSET
1895 : GOT_TYPE_TLS_PAIR);
1896 unsigned int got_offset;
1897 if (gsym != NULL)
1898 {
1899 gold_assert(gsym->has_got_offset(got_type));
1900 got_offset = gsym->got_offset(got_type) - target->got_size();
1901 }
1902 else
1903 {
1904 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1905 gold_assert(object->local_has_got_offset(r_sym, got_type));
1906 got_offset = (object->local_got_offset(r_sym, got_type)
1907 - target->got_size());
1908 }
1909 if (optimized_type == tls::TLSOPT_TO_IE)
1910 {
1911 gold_assert(tls_segment != NULL);
1912 this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1913 got_offset, view, view_size);
1914 break;
1915 }
1916 else if (optimized_type == tls::TLSOPT_NONE)
1917 {
1918 // Relocate the field with the offset of the pair of GOT
1919 // entries.
1920 Relocate_functions<32, false>::rel32(view, got_offset);
1921 break;
1922 }
1923 }
1924 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1925 _("unsupported reloc %u"),
1926 r_type);
1927 break;
1928
1929 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1930 case elfcpp::R_386_TLS_DESC_CALL:
1931 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE)
1932 this->fix_up_ldo(relinfo);
1933 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1934 if (optimized_type == tls::TLSOPT_TO_LE)
1935 {
1936 gold_assert(tls_segment != NULL);
1937 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
1938 rel, r_type, value, view,
1939 view_size);
1940 break;
1941 }
1942 else
1943 {
1944 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1945 ? GOT_TYPE_TLS_NOFFSET
1946 : GOT_TYPE_TLS_DESC);
1947 unsigned int got_offset;
1948 if (gsym != NULL)
1949 {
1950 gold_assert(gsym->has_got_offset(got_type));
1951 got_offset = gsym->got_offset(got_type) - target->got_size();
1952 }
1953 else
1954 {
1955 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1956 gold_assert(object->local_has_got_offset(r_sym, got_type));
1957 got_offset = (object->local_got_offset(r_sym, got_type)
1958 - target->got_size());
1959 }
1960 if (optimized_type == tls::TLSOPT_TO_IE)
1961 {
1962 gold_assert(tls_segment != NULL);
1963 this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1964 got_offset, view, view_size);
1965 break;
1966 }
1967 else if (optimized_type == tls::TLSOPT_NONE)
1968 {
1969 if (r_type == elfcpp::R_386_TLS_GOTDESC)
1970 {
1971 // Relocate the field with the offset of the pair of GOT
1972 // entries.
1973 Relocate_functions<32, false>::rel32(view, got_offset);
1974 }
1975 break;
1976 }
1977 }
1978 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1979 _("unsupported reloc %u"),
1980 r_type);
1981 break;
1982
1983 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1984 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1985 {
1986 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1987 _("both SUN and GNU model "
1988 "TLS relocations"));
1989 break;
1990 }
1991 else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE)
1992 this->fix_up_ldo(relinfo);
1993 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1994 if (optimized_type == tls::TLSOPT_TO_LE)
1995 {
1996 gold_assert(tls_segment != NULL);
1997 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1998 value, view, view_size);
1999 break;
2000 }
2001 else if (optimized_type == tls::TLSOPT_NONE)
2002 {
2003 // Relocate the field with the offset of the GOT entry for
2004 // the module index.
2005 unsigned int got_offset;
2006 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2007 - target->got_size());
2008 Relocate_functions<32, false>::rel32(view, got_offset);
2009 break;
2010 }
2011 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2012 _("unsupported reloc %u"),
2013 r_type);
2014 break;
2015
2016 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2017 // This reloc can appear in debugging sections, in which case we
2018 // won't see the TLS_LDM reloc. The local_dynamic_type field
2019 // tells us this.
2020 if (optimized_type == tls::TLSOPT_TO_LE
2021 && this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE)
2022 {
2023 gold_assert(tls_segment != NULL);
2024 value -= tls_segment->memsz();
2025 }
2026 else
2027 {
2028 // We may see the LDM later.
2029 this->ldo_addrs_.push_back(view);
2030 }
2031 Relocate_functions<32, false>::rel32(view, value);
2032 break;
2033
2034 case elfcpp::R_386_TLS_IE: // Initial-exec
2035 case elfcpp::R_386_TLS_GOTIE:
2036 case elfcpp::R_386_TLS_IE_32:
2037 if (optimized_type == tls::TLSOPT_TO_LE)
2038 {
2039 gold_assert(tls_segment != NULL);
2040 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2041 rel, r_type, value, view,
2042 view_size);
2043 break;
2044 }
2045 else if (optimized_type == tls::TLSOPT_NONE)
2046 {
2047 // Relocate the field with the offset of the GOT entry for
2048 // the tp-relative offset of the symbol.
2049 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2050 ? GOT_TYPE_TLS_OFFSET
2051 : GOT_TYPE_TLS_NOFFSET);
2052 unsigned int got_offset;
2053 if (gsym != NULL)
2054 {
2055 gold_assert(gsym->has_got_offset(got_type));
2056 got_offset = gsym->got_offset(got_type);
2057 }
2058 else
2059 {
2060 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2061 gold_assert(object->local_has_got_offset(r_sym, got_type));
2062 got_offset = object->local_got_offset(r_sym, got_type);
2063 }
2064 // For the R_386_TLS_IE relocation, we need to apply the
2065 // absolute address of the GOT entry.
2066 if (r_type == elfcpp::R_386_TLS_IE)
2067 got_offset += target->got_plt_section()->address();
2068 // All GOT offsets are relative to the end of the GOT.
2069 got_offset -= target->got_size();
2070 Relocate_functions<32, false>::rel32(view, got_offset);
2071 break;
2072 }
2073 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2074 _("unsupported reloc %u"),
2075 r_type);
2076 break;
2077
2078 case elfcpp::R_386_TLS_LE: // Local-exec
2079 // If we're creating a shared library, a dynamic relocation will
2080 // have been created for this location, so do not apply it now.
2081 if (!parameters->options().shared())
2082 {
2083 gold_assert(tls_segment != NULL);
2084 value -= tls_segment->memsz();
2085 Relocate_functions<32, false>::rel32(view, value);
2086 }
2087 break;
2088
2089 case elfcpp::R_386_TLS_LE_32:
2090 // If we're creating a shared library, a dynamic relocation will
2091 // have been created for this location, so do not apply it now.
2092 if (!parameters->options().shared())
2093 {
2094 gold_assert(tls_segment != NULL);
2095 value = tls_segment->memsz() - value;
2096 Relocate_functions<32, false>::rel32(view, value);
2097 }
2098 break;
2099 }
2100 }
2101
2102 // Do a relocation in which we convert a TLS General-Dynamic to a
2103 // Local-Exec.
2104
2105 inline void
2106 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2107 size_t relnum,
2108 Output_segment* tls_segment,
2109 const elfcpp::Rel<32, false>& rel,
2110 unsigned int,
2111 elfcpp::Elf_types<32>::Elf_Addr value,
2112 unsigned char* view,
2113 section_size_type view_size)
2114 {
2115 // leal foo(,%reg,1),%eax; call ___tls_get_addr
2116 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2117 // leal foo(%reg),%eax; call ___tls_get_addr
2118 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2119
2120 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2121 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2122
2123 unsigned char op1 = view[-1];
2124 unsigned char op2 = view[-2];
2125
2126 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2127 op2 == 0x8d || op2 == 0x04);
2128 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2129
2130 int roff = 5;
2131
2132 if (op2 == 0x04)
2133 {
2134 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2135 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2136 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2137 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2138 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2139 }
2140 else
2141 {
2142 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2143 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2144 if (rel.get_r_offset() + 9 < view_size
2145 && view[9] == 0x90)
2146 {
2147 // There is a trailing nop. Use the size byte subl.
2148 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2149 roff = 6;
2150 }
2151 else
2152 {
2153 // Use the five byte subl.
2154 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2155 }
2156 }
2157
2158 value = tls_segment->memsz() - value;
2159 Relocate_functions<32, false>::rel32(view + roff, value);
2160
2161 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2162 // We can skip it.
2163 this->skip_call_tls_get_addr_ = true;
2164 }
2165
2166 // Do a relocation in which we convert a TLS General-Dynamic to an
2167 // Initial-Exec.
2168
2169 inline void
2170 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2171 size_t relnum,
2172 Output_segment*,
2173 const elfcpp::Rel<32, false>& rel,
2174 unsigned int,
2175 elfcpp::Elf_types<32>::Elf_Addr value,
2176 unsigned char* view,
2177 section_size_type view_size)
2178 {
2179 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2180 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2181
2182 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2183 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2184
2185 unsigned char op1 = view[-1];
2186 unsigned char op2 = view[-2];
2187
2188 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2189 op2 == 0x8d || op2 == 0x04);
2190 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2191
2192 int roff = 5;
2193
2194 // FIXME: For now, support only the first (SIB) form.
2195 tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2196
2197 if (op2 == 0x04)
2198 {
2199 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2200 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2201 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2202 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2203 memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2204 }
2205 else
2206 {
2207 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2208 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2209 if (rel.get_r_offset() + 9 < view_size
2210 && view[9] == 0x90)
2211 {
2212 // FIXME: This is not the right instruction sequence.
2213 // There is a trailing nop. Use the size byte subl.
2214 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2215 roff = 6;
2216 }
2217 else
2218 {
2219 // FIXME: This is not the right instruction sequence.
2220 // Use the five byte subl.
2221 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2222 }
2223 }
2224
2225 Relocate_functions<32, false>::rel32(view + roff, value);
2226
2227 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2228 // We can skip it.
2229 this->skip_call_tls_get_addr_ = true;
2230 }
2231
2232 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2233 // General-Dynamic to a Local-Exec.
2234
2235 inline void
2236 Target_i386::Relocate::tls_desc_gd_to_le(
2237 const Relocate_info<32, false>* relinfo,
2238 size_t relnum,
2239 Output_segment* tls_segment,
2240 const elfcpp::Rel<32, false>& rel,
2241 unsigned int r_type,
2242 elfcpp::Elf_types<32>::Elf_Addr value,
2243 unsigned char* view,
2244 section_size_type view_size)
2245 {
2246 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2247 {
2248 // leal foo@TLSDESC(%ebx), %eax
2249 // ==> leal foo@NTPOFF, %eax
2250 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2251 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2252 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2253 view[-2] == 0x8d && view[-1] == 0x83);
2254 view[-1] = 0x05;
2255 value -= tls_segment->memsz();
2256 Relocate_functions<32, false>::rel32(view, value);
2257 }
2258 else
2259 {
2260 // call *foo@TLSCALL(%eax)
2261 // ==> nop; nop
2262 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2263 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2264 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2265 view[0] == 0xff && view[1] == 0x10);
2266 view[0] = 0x66;
2267 view[1] = 0x90;
2268 }
2269 }
2270
2271 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2272 // General-Dynamic to an Initial-Exec.
2273
2274 inline void
2275 Target_i386::Relocate::tls_desc_gd_to_ie(
2276 const Relocate_info<32, false>* relinfo,
2277 size_t relnum,
2278 Output_segment*,
2279 const elfcpp::Rel<32, false>& rel,
2280 unsigned int r_type,
2281 elfcpp::Elf_types<32>::Elf_Addr value,
2282 unsigned char* view,
2283 section_size_type view_size)
2284 {
2285 if (r_type == elfcpp::R_386_TLS_GOTDESC)
2286 {
2287 // leal foo@TLSDESC(%ebx), %eax
2288 // ==> movl foo@GOTNTPOFF(%ebx), %eax
2289 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2290 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2291 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2292 view[-2] == 0x8d && view[-1] == 0x83);
2293 view[-2] = 0x8b;
2294 Relocate_functions<32, false>::rel32(view, value);
2295 }
2296 else
2297 {
2298 // call *foo@TLSCALL(%eax)
2299 // ==> nop; nop
2300 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2301 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2302 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2303 view[0] == 0xff && view[1] == 0x10);
2304 view[0] = 0x66;
2305 view[1] = 0x90;
2306 }
2307 }
2308
2309 // Do a relocation in which we convert a TLS Local-Dynamic to a
2310 // Local-Exec.
2311
2312 inline void
2313 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2314 size_t relnum,
2315 Output_segment*,
2316 const elfcpp::Rel<32, false>& rel,
2317 unsigned int,
2318 elfcpp::Elf_types<32>::Elf_Addr,
2319 unsigned char* view,
2320 section_size_type view_size)
2321 {
2322 // leal foo(%reg), %eax; call ___tls_get_addr
2323 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2324
2325 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2326 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2327
2328 // FIXME: Does this test really always pass?
2329 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2330 view[-2] == 0x8d && view[-1] == 0x83);
2331
2332 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2333
2334 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2335
2336 // The next reloc should be a PLT32 reloc against __tls_get_addr.
2337 // We can skip it.
2338 this->skip_call_tls_get_addr_ = true;
2339 }
2340
2341 // Do a relocation in which we convert a TLS Initial-Exec to a
2342 // Local-Exec.
2343
2344 inline void
2345 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2346 size_t relnum,
2347 Output_segment* tls_segment,
2348 const elfcpp::Rel<32, false>& rel,
2349 unsigned int r_type,
2350 elfcpp::Elf_types<32>::Elf_Addr value,
2351 unsigned char* view,
2352 section_size_type view_size)
2353 {
2354 // We have to actually change the instructions, which means that we
2355 // need to examine the opcodes to figure out which instruction we
2356 // are looking at.
2357 if (r_type == elfcpp::R_386_TLS_IE)
2358 {
2359 // movl %gs:XX,%eax ==> movl $YY,%eax
2360 // movl %gs:XX,%reg ==> movl $YY,%reg
2361 // addl %gs:XX,%reg ==> addl $YY,%reg
2362 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2363 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2364
2365 unsigned char op1 = view[-1];
2366 if (op1 == 0xa1)
2367 {
2368 // movl XX,%eax ==> movl $YY,%eax
2369 view[-1] = 0xb8;
2370 }
2371 else
2372 {
2373 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2374
2375 unsigned char op2 = view[-2];
2376 if (op2 == 0x8b)
2377 {
2378 // movl XX,%reg ==> movl $YY,%reg
2379 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2380 (op1 & 0xc7) == 0x05);
2381 view[-2] = 0xc7;
2382 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2383 }
2384 else if (op2 == 0x03)
2385 {
2386 // addl XX,%reg ==> addl $YY,%reg
2387 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2388 (op1 & 0xc7) == 0x05);
2389 view[-2] = 0x81;
2390 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2391 }
2392 else
2393 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2394 }
2395 }
2396 else
2397 {
2398 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2399 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2400 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2401 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2402 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2403
2404 unsigned char op1 = view[-1];
2405 unsigned char op2 = view[-2];
2406 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2407 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2408 if (op2 == 0x8b)
2409 {
2410 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
2411 view[-2] = 0xc7;
2412 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2413 }
2414 else if (op2 == 0x2b)
2415 {
2416 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
2417 view[-2] = 0x81;
2418 view[-1] = 0xe8 | ((op1 >> 3) & 7);
2419 }
2420 else if (op2 == 0x03)
2421 {
2422 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
2423 view[-2] = 0x81;
2424 view[-1] = 0xc0 | ((op1 >> 3) & 7);
2425 }
2426 else
2427 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2428 }
2429
2430 value = tls_segment->memsz() - value;
2431 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2432 value = - value;
2433
2434 Relocate_functions<32, false>::rel32(view, value);
2435 }
2436
2437 // If we see an LDM reloc after we handled any LDO_32 relocs, fix up
2438 // the LDO_32 relocs.
2439
2440 void
2441 Target_i386::Relocate::fix_up_ldo(const Relocate_info<32, false>* relinfo)
2442 {
2443 if (this->ldo_addrs_.empty())
2444 return;
2445 Output_segment* tls_segment = relinfo->layout->tls_segment();
2446 gold_assert(tls_segment != NULL);
2447 elfcpp::Elf_types<32>::Elf_Addr value = - tls_segment->memsz();
2448 for (std::vector<unsigned char*>::const_iterator p = this->ldo_addrs_.begin();
2449 p != this->ldo_addrs_.end();
2450 ++p)
2451 Relocate_functions<32, false>::rel32(*p, value);
2452 this->ldo_addrs_.clear();
2453 }
2454
2455 // Relocate section data.
2456
2457 void
2458 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2459 unsigned int sh_type,
2460 const unsigned char* prelocs,
2461 size_t reloc_count,
2462 Output_section* output_section,
2463 bool needs_special_offset_handling,
2464 unsigned char* view,
2465 elfcpp::Elf_types<32>::Elf_Addr address,
2466 section_size_type view_size)
2467 {
2468 gold_assert(sh_type == elfcpp::SHT_REL);
2469
2470 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2471 Target_i386::Relocate>(
2472 relinfo,
2473 this,
2474 prelocs,
2475 reloc_count,
2476 output_section,
2477 needs_special_offset_handling,
2478 view,
2479 address,
2480 view_size);
2481 }
2482
2483 // Return the size of a relocation while scanning during a relocatable
2484 // link.
2485
2486 unsigned int
2487 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2488 unsigned int r_type,
2489 Relobj* object)
2490 {
2491 switch (r_type)
2492 {
2493 case elfcpp::R_386_NONE:
2494 case elfcpp::R_386_GNU_VTINHERIT:
2495 case elfcpp::R_386_GNU_VTENTRY:
2496 case elfcpp::R_386_TLS_GD: // Global-dynamic
2497 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2498 case elfcpp::R_386_TLS_DESC_CALL:
2499 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2500 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2501 case elfcpp::R_386_TLS_IE: // Initial-exec
2502 case elfcpp::R_386_TLS_IE_32:
2503 case elfcpp::R_386_TLS_GOTIE:
2504 case elfcpp::R_386_TLS_LE: // Local-exec
2505 case elfcpp::R_386_TLS_LE_32:
2506 return 0;
2507
2508 case elfcpp::R_386_32:
2509 case elfcpp::R_386_PC32:
2510 case elfcpp::R_386_GOT32:
2511 case elfcpp::R_386_PLT32:
2512 case elfcpp::R_386_GOTOFF:
2513 case elfcpp::R_386_GOTPC:
2514 return 4;
2515
2516 case elfcpp::R_386_16:
2517 case elfcpp::R_386_PC16:
2518 return 2;
2519
2520 case elfcpp::R_386_8:
2521 case elfcpp::R_386_PC8:
2522 return 1;
2523
2524 // These are relocations which should only be seen by the
2525 // dynamic linker, and should never be seen here.
2526 case elfcpp::R_386_COPY:
2527 case elfcpp::R_386_GLOB_DAT:
2528 case elfcpp::R_386_JUMP_SLOT:
2529 case elfcpp::R_386_RELATIVE:
2530 case elfcpp::R_386_TLS_TPOFF:
2531 case elfcpp::R_386_TLS_DTPMOD32:
2532 case elfcpp::R_386_TLS_DTPOFF32:
2533 case elfcpp::R_386_TLS_TPOFF32:
2534 case elfcpp::R_386_TLS_DESC:
2535 object->error(_("unexpected reloc %u in object file"), r_type);
2536 return 0;
2537
2538 case elfcpp::R_386_32PLT:
2539 case elfcpp::R_386_TLS_GD_32:
2540 case elfcpp::R_386_TLS_GD_PUSH:
2541 case elfcpp::R_386_TLS_GD_CALL:
2542 case elfcpp::R_386_TLS_GD_POP:
2543 case elfcpp::R_386_TLS_LDM_32:
2544 case elfcpp::R_386_TLS_LDM_PUSH:
2545 case elfcpp::R_386_TLS_LDM_CALL:
2546 case elfcpp::R_386_TLS_LDM_POP:
2547 case elfcpp::R_386_USED_BY_INTEL_200:
2548 default:
2549 object->error(_("unsupported reloc %u in object file"), r_type);
2550 return 0;
2551 }
2552 }
2553
2554 // Scan the relocs during a relocatable link.
2555
2556 void
2557 Target_i386::scan_relocatable_relocs(const General_options& options,
2558 Symbol_table* symtab,
2559 Layout* layout,
2560 Sized_relobj<32, false>* object,
2561 unsigned int data_shndx,
2562 unsigned int sh_type,
2563 const unsigned char* prelocs,
2564 size_t reloc_count,
2565 Output_section* output_section,
2566 bool needs_special_offset_handling,
2567 size_t local_symbol_count,
2568 const unsigned char* plocal_symbols,
2569 Relocatable_relocs* rr)
2570 {
2571 gold_assert(sh_type == elfcpp::SHT_REL);
2572
2573 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2574 Relocatable_size_for_reloc> Scan_relocatable_relocs;
2575
2576 gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2577 Scan_relocatable_relocs>(
2578 options,
2579 symtab,
2580 layout,
2581 object,
2582 data_shndx,
2583 prelocs,
2584 reloc_count,
2585 output_section,
2586 needs_special_offset_handling,
2587 local_symbol_count,
2588 plocal_symbols,
2589 rr);
2590 }
2591
2592 // Relocate a section during a relocatable link.
2593
2594 void
2595 Target_i386::relocate_for_relocatable(
2596 const Relocate_info<32, false>* relinfo,
2597 unsigned int sh_type,
2598 const unsigned char* prelocs,
2599 size_t reloc_count,
2600 Output_section* output_section,
2601 off_t offset_in_output_section,
2602 const Relocatable_relocs* rr,
2603 unsigned char* view,
2604 elfcpp::Elf_types<32>::Elf_Addr view_address,
2605 section_size_type view_size,
2606 unsigned char* reloc_view,
2607 section_size_type reloc_view_size)
2608 {
2609 gold_assert(sh_type == elfcpp::SHT_REL);
2610
2611 gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2612 relinfo,
2613 prelocs,
2614 reloc_count,
2615 output_section,
2616 offset_in_output_section,
2617 rr,
2618 view,
2619 view_address,
2620 view_size,
2621 reloc_view,
2622 reloc_view_size);
2623 }
2624
2625 // Return the value to use for a dynamic which requires special
2626 // treatment. This is how we support equality comparisons of function
2627 // pointers across shared library boundaries, as described in the
2628 // processor specific ABI supplement.
2629
2630 uint64_t
2631 Target_i386::do_dynsym_value(const Symbol* gsym) const
2632 {
2633 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2634 return this->plt_section()->address() + gsym->plt_offset();
2635 }
2636
2637 // Return a string used to fill a code section with nops to take up
2638 // the specified length.
2639
2640 std::string
2641 Target_i386::do_code_fill(section_size_type length) const
2642 {
2643 if (length >= 16)
2644 {
2645 // Build a jmp instruction to skip over the bytes.
2646 unsigned char jmp[5];
2647 jmp[0] = 0xe9;
2648 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2649 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2650 + std::string(length - 5, '\0'));
2651 }
2652
2653 // Nop sequences of various lengths.
2654 const char nop1[1] = { 0x90 }; // nop
2655 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
2656 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
2657 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
2658 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
2659 0x00 }; // leal 0(%esi,1),%esi
2660 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2661 0x00, 0x00 };
2662 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2663 0x00, 0x00, 0x00 };
2664 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
2665 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2666 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
2667 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
2668 0x00 };
2669 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2670 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2671 0x00, 0x00 };
2672 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2673 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2674 0x00, 0x00, 0x00 };
2675 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2676 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2677 0x00, 0x00, 0x00, 0x00 };
2678 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2679 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2680 0x27, 0x00, 0x00, 0x00,
2681 0x00 };
2682 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2683 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2684 0xbc, 0x27, 0x00, 0x00,
2685 0x00, 0x00 };
2686 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2687 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2688 0x90, 0x90, 0x90, 0x90,
2689 0x90, 0x90, 0x90 };
2690
2691 const char* nops[16] = {
2692 NULL,
2693 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2694 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2695 };
2696
2697 return std::string(nops[length], length);
2698 }
2699
2700 // The selector for i386 object files.
2701
2702 class Target_selector_i386 : public Target_selector_freebsd
2703 {
2704 public:
2705 Target_selector_i386()
2706 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2707 "elf32-i386", "elf32-i386-freebsd")
2708 { }
2709
2710 Target*
2711 do_instantiate_target()
2712 { return new Target_i386(); }
2713 };
2714
2715 Target_selector_i386 target_selector_i386;
2716
2717 } // End anonymous namespace.
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