Fix breakage for SHT_REL targets where get_r_addend() gives internal error.
[deliverable/binutils-gdb.git] / gold / i386.cc
1 // i386.cc -- i386 target support for gold.
2
3 // Copyright (C) 2006-2016 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cstring>
26
27 #include "elfcpp.h"
28 #include "dwarf.h"
29 #include "parameters.h"
30 #include "reloc.h"
31 #include "i386.h"
32 #include "object.h"
33 #include "symtab.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "copy-relocs.h"
37 #include "target.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
40 #include "tls.h"
41 #include "freebsd.h"
42 #include "nacl.h"
43 #include "gc.h"
44
45 namespace
46 {
47
48 using namespace gold;
49
50 // A class to handle the .got.plt section.
51
52 class Output_data_got_plt_i386 : public Output_section_data_build
53 {
54 public:
55 Output_data_got_plt_i386(Layout* layout)
56 : Output_section_data_build(4),
57 layout_(layout)
58 { }
59
60 protected:
61 // Write out the PLT data.
62 void
63 do_write(Output_file*);
64
65 // Write to a map file.
66 void
67 do_print_to_mapfile(Mapfile* mapfile) const
68 { mapfile->print_output_data(this, "** GOT PLT"); }
69
70 private:
71 // A pointer to the Layout class, so that we can find the .dynamic
72 // section when we write out the GOT PLT section.
73 Layout* layout_;
74 };
75
76 // A class to handle the PLT data.
77 // This is an abstract base class that handles most of the linker details
78 // but does not know the actual contents of PLT entries. The derived
79 // classes below fill in those details.
80
81 class Output_data_plt_i386 : public Output_section_data
82 {
83 public:
84 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
85
86 Output_data_plt_i386(Layout*, uint64_t addralign,
87 Output_data_got_plt_i386*, Output_data_space*);
88
89 // Add an entry to the PLT.
90 void
91 add_entry(Symbol_table*, Layout*, Symbol* gsym);
92
93 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
94 unsigned int
95 add_local_ifunc_entry(Symbol_table*, Layout*,
96 Sized_relobj_file<32, false>* relobj,
97 unsigned int local_sym_index);
98
99 // Return the .rel.plt section data.
100 Reloc_section*
101 rel_plt() const
102 { return this->rel_; }
103
104 // Return where the TLS_DESC relocations should go.
105 Reloc_section*
106 rel_tls_desc(Layout*);
107
108 // Return where the IRELATIVE relocations should go.
109 Reloc_section*
110 rel_irelative(Symbol_table*, Layout*);
111
112 // Return whether we created a section for IRELATIVE relocations.
113 bool
114 has_irelative_section() const
115 { return this->irelative_rel_ != NULL; }
116
117 // Return the number of PLT entries.
118 unsigned int
119 entry_count() const
120 { return this->count_ + this->irelative_count_; }
121
122 // Return the offset of the first non-reserved PLT entry.
123 unsigned int
124 first_plt_entry_offset()
125 { return this->get_plt_entry_size(); }
126
127 // Return the size of a PLT entry.
128 unsigned int
129 get_plt_entry_size() const
130 { return this->do_get_plt_entry_size(); }
131
132 // Return the PLT address to use for a global symbol.
133 uint64_t
134 address_for_global(const Symbol*);
135
136 // Return the PLT address to use for a local symbol.
137 uint64_t
138 address_for_local(const Relobj*, unsigned int symndx);
139
140 // Add .eh_frame information for the PLT.
141 void
142 add_eh_frame(Layout* layout)
143 { this->do_add_eh_frame(layout); }
144
145 protected:
146 // Fill the first PLT entry, given the pointer to the PLT section data
147 // and the runtime address of the GOT.
148 void
149 fill_first_plt_entry(unsigned char* pov,
150 elfcpp::Elf_types<32>::Elf_Addr got_address)
151 { this->do_fill_first_plt_entry(pov, got_address); }
152
153 // Fill a normal PLT entry, given the pointer to the entry's data in the
154 // section, the runtime address of the GOT, the offset into the GOT of
155 // the corresponding slot, the offset into the relocation section of the
156 // corresponding reloc, and the offset of this entry within the whole
157 // PLT. Return the offset from this PLT entry's runtime address that
158 // should be used to compute the initial value of the GOT slot.
159 unsigned int
160 fill_plt_entry(unsigned char* pov,
161 elfcpp::Elf_types<32>::Elf_Addr got_address,
162 unsigned int got_offset,
163 unsigned int plt_offset,
164 unsigned int plt_rel_offset)
165 {
166 return this->do_fill_plt_entry(pov, got_address, got_offset,
167 plt_offset, plt_rel_offset);
168 }
169
170 virtual unsigned int
171 do_get_plt_entry_size() const = 0;
172
173 virtual void
174 do_fill_first_plt_entry(unsigned char* pov,
175 elfcpp::Elf_types<32>::Elf_Addr got_address) = 0;
176
177 virtual unsigned int
178 do_fill_plt_entry(unsigned char* pov,
179 elfcpp::Elf_types<32>::Elf_Addr got_address,
180 unsigned int got_offset,
181 unsigned int plt_offset,
182 unsigned int plt_rel_offset) = 0;
183
184 virtual void
185 do_add_eh_frame(Layout*) = 0;
186
187 void
188 do_adjust_output_section(Output_section* os);
189
190 // Write to a map file.
191 void
192 do_print_to_mapfile(Mapfile* mapfile) const
193 { mapfile->print_output_data(this, _("** PLT")); }
194
195 // The .eh_frame unwind information for the PLT.
196 // The CIE is common across variants of the PLT format.
197 static const int plt_eh_frame_cie_size = 16;
198 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
199
200 private:
201 // Set the final size.
202 void
203 set_final_data_size()
204 {
205 this->set_data_size((this->count_ + this->irelative_count_ + 1)
206 * this->get_plt_entry_size());
207 }
208
209 // Write out the PLT data.
210 void
211 do_write(Output_file*);
212
213 // We keep a list of global STT_GNU_IFUNC symbols, each with its
214 // offset in the GOT.
215 struct Global_ifunc
216 {
217 Symbol* sym;
218 unsigned int got_offset;
219 };
220
221 // We keep a list of local STT_GNU_IFUNC symbols, each with its
222 // offset in the GOT.
223 struct Local_ifunc
224 {
225 Sized_relobj_file<32, false>* object;
226 unsigned int local_sym_index;
227 unsigned int got_offset;
228 };
229
230 // The reloc section.
231 Reloc_section* rel_;
232 // The TLS_DESC relocations, if necessary. These must follow the
233 // regular PLT relocs.
234 Reloc_section* tls_desc_rel_;
235 // The IRELATIVE relocations, if necessary. These must follow the
236 // regular relocatoins and the TLS_DESC relocations.
237 Reloc_section* irelative_rel_;
238 // The .got.plt section.
239 Output_data_got_plt_i386* got_plt_;
240 // The part of the .got.plt section used for IRELATIVE relocs.
241 Output_data_space* got_irelative_;
242 // The number of PLT entries.
243 unsigned int count_;
244 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
245 // the regular PLT entries.
246 unsigned int irelative_count_;
247 // Global STT_GNU_IFUNC symbols.
248 std::vector<Global_ifunc> global_ifuncs_;
249 // Local STT_GNU_IFUNC symbols.
250 std::vector<Local_ifunc> local_ifuncs_;
251 };
252
253 // This is an abstract class for the standard PLT layout.
254 // The derived classes below handle the actual PLT contents
255 // for the executable (non-PIC) and shared-library (PIC) cases.
256 // The unwind information is uniform across those two, so it's here.
257
258 class Output_data_plt_i386_standard : public Output_data_plt_i386
259 {
260 public:
261 Output_data_plt_i386_standard(Layout* layout,
262 Output_data_got_plt_i386* got_plt,
263 Output_data_space* got_irelative)
264 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
265 { }
266
267 protected:
268 virtual unsigned int
269 do_get_plt_entry_size() const
270 { return plt_entry_size; }
271
272 virtual void
273 do_add_eh_frame(Layout* layout)
274 {
275 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
276 plt_eh_frame_fde, plt_eh_frame_fde_size);
277 }
278
279 // The size of an entry in the PLT.
280 static const int plt_entry_size = 16;
281
282 // The .eh_frame unwind information for the PLT.
283 static const int plt_eh_frame_fde_size = 32;
284 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
285 };
286
287 // Actually fill the PLT contents for an executable (non-PIC).
288
289 class Output_data_plt_i386_exec : public Output_data_plt_i386_standard
290 {
291 public:
292 Output_data_plt_i386_exec(Layout* layout,
293 Output_data_got_plt_i386* got_plt,
294 Output_data_space* got_irelative)
295 : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
296 { }
297
298 protected:
299 virtual void
300 do_fill_first_plt_entry(unsigned char* pov,
301 elfcpp::Elf_types<32>::Elf_Addr got_address);
302
303 virtual unsigned int
304 do_fill_plt_entry(unsigned char* pov,
305 elfcpp::Elf_types<32>::Elf_Addr got_address,
306 unsigned int got_offset,
307 unsigned int plt_offset,
308 unsigned int plt_rel_offset);
309
310 private:
311 // The first entry in the PLT for an executable.
312 static const unsigned char first_plt_entry[plt_entry_size];
313
314 // Other entries in the PLT for an executable.
315 static const unsigned char plt_entry[plt_entry_size];
316 };
317
318 // Actually fill the PLT contents for a shared library (PIC).
319
320 class Output_data_plt_i386_dyn : public Output_data_plt_i386_standard
321 {
322 public:
323 Output_data_plt_i386_dyn(Layout* layout,
324 Output_data_got_plt_i386* got_plt,
325 Output_data_space* got_irelative)
326 : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
327 { }
328
329 protected:
330 virtual void
331 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
332
333 virtual unsigned int
334 do_fill_plt_entry(unsigned char* pov,
335 elfcpp::Elf_types<32>::Elf_Addr,
336 unsigned int got_offset,
337 unsigned int plt_offset,
338 unsigned int plt_rel_offset);
339
340 private:
341 // The first entry in the PLT for a shared object.
342 static const unsigned char first_plt_entry[plt_entry_size];
343
344 // Other entries in the PLT for a shared object.
345 static const unsigned char plt_entry[plt_entry_size];
346 };
347
348 // The i386 target class.
349 // TLS info comes from
350 // http://people.redhat.com/drepper/tls.pdf
351 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
352
353 class Target_i386 : public Sized_target<32, false>
354 {
355 public:
356 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
357
358 Target_i386(const Target::Target_info* info = &i386_info)
359 : Sized_target<32, false>(info),
360 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
361 got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
362 rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY),
363 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
364 { }
365
366 // Process the relocations to determine unreferenced sections for
367 // garbage collection.
368 void
369 gc_process_relocs(Symbol_table* symtab,
370 Layout* layout,
371 Sized_relobj_file<32, false>* object,
372 unsigned int data_shndx,
373 unsigned int sh_type,
374 const unsigned char* prelocs,
375 size_t reloc_count,
376 Output_section* output_section,
377 bool needs_special_offset_handling,
378 size_t local_symbol_count,
379 const unsigned char* plocal_symbols);
380
381 // Scan the relocations to look for symbol adjustments.
382 void
383 scan_relocs(Symbol_table* symtab,
384 Layout* layout,
385 Sized_relobj_file<32, false>* object,
386 unsigned int data_shndx,
387 unsigned int sh_type,
388 const unsigned char* prelocs,
389 size_t reloc_count,
390 Output_section* output_section,
391 bool needs_special_offset_handling,
392 size_t local_symbol_count,
393 const unsigned char* plocal_symbols);
394
395 // Finalize the sections.
396 void
397 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
398
399 // Return the value to use for a dynamic which requires special
400 // treatment.
401 uint64_t
402 do_dynsym_value(const Symbol*) const;
403
404 // Relocate a section.
405 void
406 relocate_section(const Relocate_info<32, false>*,
407 unsigned int sh_type,
408 const unsigned char* prelocs,
409 size_t reloc_count,
410 Output_section* output_section,
411 bool needs_special_offset_handling,
412 unsigned char* view,
413 elfcpp::Elf_types<32>::Elf_Addr view_address,
414 section_size_type view_size,
415 const Reloc_symbol_changes*);
416
417 // Scan the relocs during a relocatable link.
418 void
419 scan_relocatable_relocs(Symbol_table* symtab,
420 Layout* layout,
421 Sized_relobj_file<32, false>* object,
422 unsigned int data_shndx,
423 unsigned int sh_type,
424 const unsigned char* prelocs,
425 size_t reloc_count,
426 Output_section* output_section,
427 bool needs_special_offset_handling,
428 size_t local_symbol_count,
429 const unsigned char* plocal_symbols,
430 Relocatable_relocs*);
431
432 // Scan the relocs for --emit-relocs.
433 void
434 emit_relocs_scan(Symbol_table* symtab,
435 Layout* layout,
436 Sized_relobj_file<32, false>* object,
437 unsigned int data_shndx,
438 unsigned int sh_type,
439 const unsigned char* prelocs,
440 size_t reloc_count,
441 Output_section* output_section,
442 bool needs_special_offset_handling,
443 size_t local_symbol_count,
444 const unsigned char* plocal_syms,
445 Relocatable_relocs* rr);
446
447 // Emit relocations for a section.
448 void
449 relocate_relocs(const Relocate_info<32, false>*,
450 unsigned int sh_type,
451 const unsigned char* prelocs,
452 size_t reloc_count,
453 Output_section* output_section,
454 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
455 unsigned char* view,
456 elfcpp::Elf_types<32>::Elf_Addr view_address,
457 section_size_type view_size,
458 unsigned char* reloc_view,
459 section_size_type reloc_view_size);
460
461 // Return a string used to fill a code section with nops.
462 std::string
463 do_code_fill(section_size_type length) const;
464
465 // Return whether SYM is defined by the ABI.
466 bool
467 do_is_defined_by_abi(const Symbol* sym) const
468 { return strcmp(sym->name(), "___tls_get_addr") == 0; }
469
470 // Return whether a symbol name implies a local label. The UnixWare
471 // 2.1 cc generates temporary symbols that start with .X, so we
472 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
473 // If so, we should move the .X recognition into
474 // Target::do_is_local_label_name.
475 bool
476 do_is_local_label_name(const char* name) const
477 {
478 if (name[0] == '.' && name[1] == 'X')
479 return true;
480 return Target::do_is_local_label_name(name);
481 }
482
483 // Return the PLT address to use for a global symbol.
484 uint64_t
485 do_plt_address_for_global(const Symbol* gsym) const
486 { return this->plt_section()->address_for_global(gsym); }
487
488 uint64_t
489 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
490 { return this->plt_section()->address_for_local(relobj, symndx); }
491
492 // We can tell whether we take the address of a function.
493 inline bool
494 do_can_check_for_function_pointers() const
495 { return true; }
496
497 // Return the base for a DW_EH_PE_datarel encoding.
498 uint64_t
499 do_ehframe_datarel_base() const;
500
501 // Return whether SYM is call to a non-split function.
502 bool
503 do_is_call_to_non_split(const Symbol* sym, const unsigned char*) const;
504
505 // Adjust -fsplit-stack code which calls non-split-stack code.
506 void
507 do_calls_non_split(Relobj* object, unsigned int shndx,
508 section_offset_type fnoffset, section_size_type fnsize,
509 const unsigned char* prelocs, size_t reloc_count,
510 unsigned char* view, section_size_type view_size,
511 std::string* from, std::string* to) const;
512
513 // Return the size of the GOT section.
514 section_size_type
515 got_size() const
516 {
517 gold_assert(this->got_ != NULL);
518 return this->got_->data_size();
519 }
520
521 // Return the number of entries in the GOT.
522 unsigned int
523 got_entry_count() const
524 {
525 if (this->got_ == NULL)
526 return 0;
527 return this->got_size() / 4;
528 }
529
530 // Return the number of entries in the PLT.
531 unsigned int
532 plt_entry_count() const;
533
534 // Return the offset of the first non-reserved PLT entry.
535 unsigned int
536 first_plt_entry_offset() const;
537
538 // Return the size of each PLT entry.
539 unsigned int
540 plt_entry_size() const;
541
542 protected:
543 // Instantiate the plt_ member.
544 // This chooses the right PLT flavor for an executable or a shared object.
545 Output_data_plt_i386*
546 make_data_plt(Layout* layout,
547 Output_data_got_plt_i386* got_plt,
548 Output_data_space* got_irelative,
549 bool dyn)
550 { return this->do_make_data_plt(layout, got_plt, got_irelative, dyn); }
551
552 virtual Output_data_plt_i386*
553 do_make_data_plt(Layout* layout,
554 Output_data_got_plt_i386* got_plt,
555 Output_data_space* got_irelative,
556 bool dyn)
557 {
558 if (dyn)
559 return new Output_data_plt_i386_dyn(layout, got_plt, got_irelative);
560 else
561 return new Output_data_plt_i386_exec(layout, got_plt, got_irelative);
562 }
563
564 private:
565 // The class which scans relocations.
566 struct Scan
567 {
568 static inline int
569
570 get_reference_flags(unsigned int r_type);
571
572 inline void
573 local(Symbol_table* symtab, Layout* layout, Target_i386* target,
574 Sized_relobj_file<32, false>* object,
575 unsigned int data_shndx,
576 Output_section* output_section,
577 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
578 const elfcpp::Sym<32, false>& lsym,
579 bool is_discarded);
580
581 inline void
582 global(Symbol_table* symtab, Layout* layout, Target_i386* target,
583 Sized_relobj_file<32, false>* object,
584 unsigned int data_shndx,
585 Output_section* output_section,
586 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
587 Symbol* gsym);
588
589 inline bool
590 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
591 Target_i386* target,
592 Sized_relobj_file<32, false>* object,
593 unsigned int data_shndx,
594 Output_section* output_section,
595 const elfcpp::Rel<32, false>& reloc,
596 unsigned int r_type,
597 const elfcpp::Sym<32, false>& lsym);
598
599 inline bool
600 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
601 Target_i386* target,
602 Sized_relobj_file<32, false>* object,
603 unsigned int data_shndx,
604 Output_section* output_section,
605 const elfcpp::Rel<32, false>& reloc,
606 unsigned int r_type,
607 Symbol* gsym);
608
609 inline bool
610 possible_function_pointer_reloc(unsigned int r_type);
611
612 bool
613 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
614 unsigned int r_type);
615
616 static void
617 unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
618
619 static void
620 unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
621 Symbol*);
622 };
623
624 // The class which implements relocation.
625 class Relocate
626 {
627 public:
628 Relocate()
629 : skip_call_tls_get_addr_(false),
630 local_dynamic_type_(LOCAL_DYNAMIC_NONE)
631 { }
632
633 ~Relocate()
634 {
635 if (this->skip_call_tls_get_addr_)
636 {
637 // FIXME: This needs to specify the location somehow.
638 gold_error(_("missing expected TLS relocation"));
639 }
640 }
641
642 // Return whether the static relocation needs to be applied.
643 inline bool
644 should_apply_static_reloc(const Sized_symbol<32>* gsym,
645 unsigned int r_type,
646 bool is_32bit,
647 Output_section* output_section);
648
649 // Do a relocation. Return false if the caller should not issue
650 // any warnings about this relocation.
651 inline bool
652 relocate(const Relocate_info<32, false>*, unsigned int,
653 Target_i386*, Output_section*, size_t, const unsigned char*,
654 const Sized_symbol<32>*, const Symbol_value<32>*,
655 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
656 section_size_type);
657
658 private:
659 // Do a TLS relocation.
660 inline void
661 relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
662 size_t relnum, const elfcpp::Rel<32, false>&,
663 unsigned int r_type, const Sized_symbol<32>*,
664 const Symbol_value<32>*,
665 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
666 section_size_type);
667
668 // Do a TLS General-Dynamic to Initial-Exec transition.
669 inline void
670 tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
671 const elfcpp::Rel<32, false>&, unsigned int r_type,
672 elfcpp::Elf_types<32>::Elf_Addr value,
673 unsigned char* view,
674 section_size_type view_size);
675
676 // Do a TLS General-Dynamic to Local-Exec transition.
677 inline void
678 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
679 Output_segment* tls_segment,
680 const elfcpp::Rel<32, false>&, unsigned int r_type,
681 elfcpp::Elf_types<32>::Elf_Addr value,
682 unsigned char* view,
683 section_size_type view_size);
684
685 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
686 // transition.
687 inline void
688 tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
689 const elfcpp::Rel<32, false>&, unsigned int r_type,
690 elfcpp::Elf_types<32>::Elf_Addr value,
691 unsigned char* view,
692 section_size_type view_size);
693
694 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
695 // transition.
696 inline void
697 tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
698 Output_segment* tls_segment,
699 const elfcpp::Rel<32, false>&, unsigned int r_type,
700 elfcpp::Elf_types<32>::Elf_Addr value,
701 unsigned char* view,
702 section_size_type view_size);
703
704 // Do a TLS Local-Dynamic to Local-Exec transition.
705 inline void
706 tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
707 Output_segment* tls_segment,
708 const elfcpp::Rel<32, false>&, unsigned int r_type,
709 elfcpp::Elf_types<32>::Elf_Addr value,
710 unsigned char* view,
711 section_size_type view_size);
712
713 // Do a TLS Initial-Exec to Local-Exec transition.
714 static inline void
715 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
716 Output_segment* tls_segment,
717 const elfcpp::Rel<32, false>&, unsigned int r_type,
718 elfcpp::Elf_types<32>::Elf_Addr value,
719 unsigned char* view,
720 section_size_type view_size);
721
722 // We need to keep track of which type of local dynamic relocation
723 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
724 enum Local_dynamic_type
725 {
726 LOCAL_DYNAMIC_NONE,
727 LOCAL_DYNAMIC_SUN,
728 LOCAL_DYNAMIC_GNU
729 };
730
731 // This is set if we should skip the next reloc, which should be a
732 // PLT32 reloc against ___tls_get_addr.
733 bool skip_call_tls_get_addr_;
734 // The type of local dynamic relocation we have seen in the section
735 // being relocated, if any.
736 Local_dynamic_type local_dynamic_type_;
737 };
738
739 // A class for inquiring about properties of a relocation,
740 // used while scanning relocs during a relocatable link and
741 // garbage collection.
742 class Classify_reloc :
743 public gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
744 {
745 public:
746 typedef typename Reloc_types<elfcpp::SHT_REL, 32, false>::Reloc
747 Reltype;
748
749 // Return the explicit addend of the relocation (return 0 for SHT_REL).
750 static typename elfcpp::Elf_types<32>::Elf_Swxword
751 get_r_addend(const Reltype*)
752 { return 0; }
753
754 // Return the size of the addend of the relocation (only used for SHT_REL).
755 static unsigned int
756 get_size_for_reloc(unsigned int, Relobj*);
757 };
758
759 // Adjust TLS relocation type based on the options and whether this
760 // is a local symbol.
761 static tls::Tls_optimization
762 optimize_tls_reloc(bool is_final, int r_type);
763
764 // Check if relocation against this symbol is a candidate for
765 // conversion from
766 // mov foo@GOT(%reg), %reg
767 // to
768 // lea foo@GOTOFF(%reg), %reg.
769 static bool
770 can_convert_mov_to_lea(const Symbol* gsym)
771 {
772 gold_assert(gsym != NULL);
773 return (gsym->type() != elfcpp::STT_GNU_IFUNC
774 && !gsym->is_undefined ()
775 && !gsym->is_from_dynobj()
776 && !gsym->is_preemptible()
777 && (!parameters->options().shared()
778 || (gsym->visibility() != elfcpp::STV_DEFAULT
779 && gsym->visibility() != elfcpp::STV_PROTECTED)
780 || parameters->options().Bsymbolic())
781 && strcmp(gsym->name(), "_DYNAMIC") != 0);
782 }
783
784 // Get the GOT section, creating it if necessary.
785 Output_data_got<32, false>*
786 got_section(Symbol_table*, Layout*);
787
788 // Get the GOT PLT section.
789 Output_data_got_plt_i386*
790 got_plt_section() const
791 {
792 gold_assert(this->got_plt_ != NULL);
793 return this->got_plt_;
794 }
795
796 // Get the GOT section for TLSDESC entries.
797 Output_data_got<32, false>*
798 got_tlsdesc_section() const
799 {
800 gold_assert(this->got_tlsdesc_ != NULL);
801 return this->got_tlsdesc_;
802 }
803
804 // Create the PLT section.
805 void
806 make_plt_section(Symbol_table* symtab, Layout* layout);
807
808 // Create a PLT entry for a global symbol.
809 void
810 make_plt_entry(Symbol_table*, Layout*, Symbol*);
811
812 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
813 void
814 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
815 Sized_relobj_file<32, false>* relobj,
816 unsigned int local_sym_index);
817
818 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
819 void
820 define_tls_base_symbol(Symbol_table*, Layout*);
821
822 // Create a GOT entry for the TLS module index.
823 unsigned int
824 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
825 Sized_relobj_file<32, false>* object);
826
827 // Get the PLT section.
828 Output_data_plt_i386*
829 plt_section() const
830 {
831 gold_assert(this->plt_ != NULL);
832 return this->plt_;
833 }
834
835 // Get the dynamic reloc section, creating it if necessary.
836 Reloc_section*
837 rel_dyn_section(Layout*);
838
839 // Get the section to use for TLS_DESC relocations.
840 Reloc_section*
841 rel_tls_desc_section(Layout*) const;
842
843 // Get the section to use for IRELATIVE relocations.
844 Reloc_section*
845 rel_irelative_section(Layout*);
846
847 // Add a potential copy relocation.
848 void
849 copy_reloc(Symbol_table* symtab, Layout* layout,
850 Sized_relobj_file<32, false>* object,
851 unsigned int shndx, Output_section* output_section,
852 Symbol* sym, const elfcpp::Rel<32, false>& reloc)
853 {
854 unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
855 this->copy_relocs_.copy_reloc(symtab, layout,
856 symtab->get_sized_symbol<32>(sym),
857 object, shndx, output_section,
858 r_type, reloc.get_r_offset(), 0,
859 this->rel_dyn_section(layout));
860 }
861
862 // Information about this specific target which we pass to the
863 // general Target structure.
864 static const Target::Target_info i386_info;
865
866 // The types of GOT entries needed for this platform.
867 // These values are exposed to the ABI in an incremental link.
868 // Do not renumber existing values without changing the version
869 // number of the .gnu_incremental_inputs section.
870 enum Got_type
871 {
872 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
873 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
874 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
875 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
876 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
877 };
878
879 // The GOT section.
880 Output_data_got<32, false>* got_;
881 // The PLT section.
882 Output_data_plt_i386* plt_;
883 // The GOT PLT section.
884 Output_data_got_plt_i386* got_plt_;
885 // The GOT section for IRELATIVE relocations.
886 Output_data_space* got_irelative_;
887 // The GOT section for TLSDESC relocations.
888 Output_data_got<32, false>* got_tlsdesc_;
889 // The _GLOBAL_OFFSET_TABLE_ symbol.
890 Symbol* global_offset_table_;
891 // The dynamic reloc section.
892 Reloc_section* rel_dyn_;
893 // The section to use for IRELATIVE relocs.
894 Reloc_section* rel_irelative_;
895 // Relocs saved to avoid a COPY reloc.
896 Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
897 // Offset of the GOT entry for the TLS module index.
898 unsigned int got_mod_index_offset_;
899 // True if the _TLS_MODULE_BASE_ symbol has been defined.
900 bool tls_base_symbol_defined_;
901 };
902
903 const Target::Target_info Target_i386::i386_info =
904 {
905 32, // size
906 false, // is_big_endian
907 elfcpp::EM_386, // machine_code
908 false, // has_make_symbol
909 false, // has_resolve
910 true, // has_code_fill
911 true, // is_default_stack_executable
912 true, // can_icf_inline_merge_sections
913 '\0', // wrap_char
914 "/usr/lib/libc.so.1", // dynamic_linker
915 0x08048000, // default_text_segment_address
916 0x1000, // abi_pagesize (overridable by -z max-page-size)
917 0x1000, // common_pagesize (overridable by -z common-page-size)
918 false, // isolate_execinstr
919 0, // rosegment_gap
920 elfcpp::SHN_UNDEF, // small_common_shndx
921 elfcpp::SHN_UNDEF, // large_common_shndx
922 0, // small_common_section_flags
923 0, // large_common_section_flags
924 NULL, // attributes_section
925 NULL, // attributes_vendor
926 "_start", // entry_symbol_name
927 32, // hash_entry_size
928 };
929
930 // Get the GOT section, creating it if necessary.
931
932 Output_data_got<32, false>*
933 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
934 {
935 if (this->got_ == NULL)
936 {
937 gold_assert(symtab != NULL && layout != NULL);
938
939 this->got_ = new Output_data_got<32, false>();
940
941 // When using -z now, we can treat .got.plt as a relro section.
942 // Without -z now, it is modified after program startup by lazy
943 // PLT relocations.
944 bool is_got_plt_relro = parameters->options().now();
945 Output_section_order got_order = (is_got_plt_relro
946 ? ORDER_RELRO
947 : ORDER_RELRO_LAST);
948 Output_section_order got_plt_order = (is_got_plt_relro
949 ? ORDER_RELRO
950 : ORDER_NON_RELRO_FIRST);
951
952 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
953 (elfcpp::SHF_ALLOC
954 | elfcpp::SHF_WRITE),
955 this->got_, got_order, true);
956
957 this->got_plt_ = new Output_data_got_plt_i386(layout);
958 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
959 (elfcpp::SHF_ALLOC
960 | elfcpp::SHF_WRITE),
961 this->got_plt_, got_plt_order,
962 is_got_plt_relro);
963
964 // The first three entries are reserved.
965 this->got_plt_->set_current_data_size(3 * 4);
966
967 if (!is_got_plt_relro)
968 {
969 // Those bytes can go into the relro segment.
970 layout->increase_relro(3 * 4);
971 }
972
973 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
974 this->global_offset_table_ =
975 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
976 Symbol_table::PREDEFINED,
977 this->got_plt_,
978 0, 0, elfcpp::STT_OBJECT,
979 elfcpp::STB_LOCAL,
980 elfcpp::STV_HIDDEN, 0,
981 false, false);
982
983 // If there are any IRELATIVE relocations, they get GOT entries
984 // in .got.plt after the jump slot relocations.
985 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
986 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
987 (elfcpp::SHF_ALLOC
988 | elfcpp::SHF_WRITE),
989 this->got_irelative_,
990 got_plt_order, is_got_plt_relro);
991
992 // If there are any TLSDESC relocations, they get GOT entries in
993 // .got.plt after the jump slot entries.
994 this->got_tlsdesc_ = new Output_data_got<32, false>();
995 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
996 (elfcpp::SHF_ALLOC
997 | elfcpp::SHF_WRITE),
998 this->got_tlsdesc_,
999 got_plt_order, is_got_plt_relro);
1000 }
1001
1002 return this->got_;
1003 }
1004
1005 // Get the dynamic reloc section, creating it if necessary.
1006
1007 Target_i386::Reloc_section*
1008 Target_i386::rel_dyn_section(Layout* layout)
1009 {
1010 if (this->rel_dyn_ == NULL)
1011 {
1012 gold_assert(layout != NULL);
1013 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
1014 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1015 elfcpp::SHF_ALLOC, this->rel_dyn_,
1016 ORDER_DYNAMIC_RELOCS, false);
1017 }
1018 return this->rel_dyn_;
1019 }
1020
1021 // Get the section to use for IRELATIVE relocs, creating it if
1022 // necessary. These go in .rel.dyn, but only after all other dynamic
1023 // relocations. They need to follow the other dynamic relocations so
1024 // that they can refer to global variables initialized by those
1025 // relocs.
1026
1027 Target_i386::Reloc_section*
1028 Target_i386::rel_irelative_section(Layout* layout)
1029 {
1030 if (this->rel_irelative_ == NULL)
1031 {
1032 // Make sure we have already create the dynamic reloc section.
1033 this->rel_dyn_section(layout);
1034 this->rel_irelative_ = new Reloc_section(false);
1035 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
1036 elfcpp::SHF_ALLOC, this->rel_irelative_,
1037 ORDER_DYNAMIC_RELOCS, false);
1038 gold_assert(this->rel_dyn_->output_section()
1039 == this->rel_irelative_->output_section());
1040 }
1041 return this->rel_irelative_;
1042 }
1043
1044 // Write the first three reserved words of the .got.plt section.
1045 // The remainder of the section is written while writing the PLT
1046 // in Output_data_plt_i386::do_write.
1047
1048 void
1049 Output_data_got_plt_i386::do_write(Output_file* of)
1050 {
1051 // The first entry in the GOT is the address of the .dynamic section
1052 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1053 // We saved space for them when we created the section in
1054 // Target_i386::got_section.
1055 const off_t got_file_offset = this->offset();
1056 gold_assert(this->data_size() >= 12);
1057 unsigned char* const got_view = of->get_output_view(got_file_offset, 12);
1058 Output_section* dynamic = this->layout_->dynamic_section();
1059 uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1060 elfcpp::Swap<32, false>::writeval(got_view, dynamic_addr);
1061 memset(got_view + 4, 0, 8);
1062 of->write_output_view(got_file_offset, 12, got_view);
1063 }
1064
1065 // Create the PLT section. The ordinary .got section is an argument,
1066 // since we need to refer to the start. We also create our own .got
1067 // section just for PLT entries.
1068
1069 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
1070 uint64_t addralign,
1071 Output_data_got_plt_i386* got_plt,
1072 Output_data_space* got_irelative)
1073 : Output_section_data(addralign),
1074 tls_desc_rel_(NULL), irelative_rel_(NULL), got_plt_(got_plt),
1075 got_irelative_(got_irelative), count_(0), irelative_count_(0),
1076 global_ifuncs_(), local_ifuncs_()
1077 {
1078 this->rel_ = new Reloc_section(false);
1079 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1080 elfcpp::SHF_ALLOC, this->rel_,
1081 ORDER_DYNAMIC_PLT_RELOCS, false);
1082 }
1083
1084 void
1085 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
1086 {
1087 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1088 // linker, and so do we.
1089 os->set_entsize(4);
1090 }
1091
1092 // Add an entry to the PLT.
1093
1094 void
1095 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
1096 Symbol* gsym)
1097 {
1098 gold_assert(!gsym->has_plt_offset());
1099
1100 // Every PLT entry needs a reloc.
1101 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1102 && gsym->can_use_relative_reloc(false))
1103 {
1104 gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
1105 ++this->irelative_count_;
1106 section_offset_type got_offset =
1107 this->got_irelative_->current_data_size();
1108 this->got_irelative_->set_current_data_size(got_offset + 4);
1109 Reloc_section* rel = this->rel_irelative(symtab, layout);
1110 rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
1111 this->got_irelative_, got_offset);
1112 struct Global_ifunc gi;
1113 gi.sym = gsym;
1114 gi.got_offset = got_offset;
1115 this->global_ifuncs_.push_back(gi);
1116 }
1117 else
1118 {
1119 // When setting the PLT offset we skip the initial reserved PLT
1120 // entry.
1121 gsym->set_plt_offset((this->count_ + 1) * this->get_plt_entry_size());
1122
1123 ++this->count_;
1124
1125 section_offset_type got_offset = this->got_plt_->current_data_size();
1126
1127 // Every PLT entry needs a GOT entry which points back to the
1128 // PLT entry (this will be changed by the dynamic linker,
1129 // normally lazily when the function is called).
1130 this->got_plt_->set_current_data_size(got_offset + 4);
1131
1132 gsym->set_needs_dynsym_entry();
1133 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
1134 got_offset);
1135 }
1136
1137 // Note that we don't need to save the symbol. The contents of the
1138 // PLT are independent of which symbols are used. The symbols only
1139 // appear in the relocations.
1140 }
1141
1142 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1143 // the PLT offset.
1144
1145 unsigned int
1146 Output_data_plt_i386::add_local_ifunc_entry(
1147 Symbol_table* symtab,
1148 Layout* layout,
1149 Sized_relobj_file<32, false>* relobj,
1150 unsigned int local_sym_index)
1151 {
1152 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1153 ++this->irelative_count_;
1154
1155 section_offset_type got_offset = this->got_irelative_->current_data_size();
1156
1157 // Every PLT entry needs a GOT entry which points back to the PLT
1158 // entry.
1159 this->got_irelative_->set_current_data_size(got_offset + 4);
1160
1161 // Every PLT entry needs a reloc.
1162 Reloc_section* rel = this->rel_irelative(symtab, layout);
1163 rel->add_symbolless_local_addend(relobj, local_sym_index,
1164 elfcpp::R_386_IRELATIVE,
1165 this->got_irelative_, got_offset);
1166
1167 struct Local_ifunc li;
1168 li.object = relobj;
1169 li.local_sym_index = local_sym_index;
1170 li.got_offset = got_offset;
1171 this->local_ifuncs_.push_back(li);
1172
1173 return plt_offset;
1174 }
1175
1176 // Return where the TLS_DESC relocations should go, creating it if
1177 // necessary. These follow the JUMP_SLOT relocations.
1178
1179 Output_data_plt_i386::Reloc_section*
1180 Output_data_plt_i386::rel_tls_desc(Layout* layout)
1181 {
1182 if (this->tls_desc_rel_ == NULL)
1183 {
1184 this->tls_desc_rel_ = new Reloc_section(false);
1185 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1186 elfcpp::SHF_ALLOC, this->tls_desc_rel_,
1187 ORDER_DYNAMIC_PLT_RELOCS, false);
1188 gold_assert(this->tls_desc_rel_->output_section()
1189 == this->rel_->output_section());
1190 }
1191 return this->tls_desc_rel_;
1192 }
1193
1194 // Return where the IRELATIVE relocations should go in the PLT. These
1195 // follow the JUMP_SLOT and TLS_DESC relocations.
1196
1197 Output_data_plt_i386::Reloc_section*
1198 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
1199 {
1200 if (this->irelative_rel_ == NULL)
1201 {
1202 // Make sure we have a place for the TLS_DESC relocations, in
1203 // case we see any later on.
1204 this->rel_tls_desc(layout);
1205 this->irelative_rel_ = new Reloc_section(false);
1206 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
1207 elfcpp::SHF_ALLOC, this->irelative_rel_,
1208 ORDER_DYNAMIC_PLT_RELOCS, false);
1209 gold_assert(this->irelative_rel_->output_section()
1210 == this->rel_->output_section());
1211
1212 if (parameters->doing_static_link())
1213 {
1214 // A statically linked executable will only have a .rel.plt
1215 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1216 // symbols. The library will use these symbols to locate
1217 // the IRELATIVE relocs at program startup time.
1218 symtab->define_in_output_data("__rel_iplt_start", NULL,
1219 Symbol_table::PREDEFINED,
1220 this->irelative_rel_, 0, 0,
1221 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1222 elfcpp::STV_HIDDEN, 0, false, true);
1223 symtab->define_in_output_data("__rel_iplt_end", NULL,
1224 Symbol_table::PREDEFINED,
1225 this->irelative_rel_, 0, 0,
1226 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1227 elfcpp::STV_HIDDEN, 0, true, true);
1228 }
1229 }
1230 return this->irelative_rel_;
1231 }
1232
1233 // Return the PLT address to use for a global symbol.
1234
1235 uint64_t
1236 Output_data_plt_i386::address_for_global(const Symbol* gsym)
1237 {
1238 uint64_t offset = 0;
1239 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1240 && gsym->can_use_relative_reloc(false))
1241 offset = (this->count_ + 1) * this->get_plt_entry_size();
1242 return this->address() + offset + gsym->plt_offset();
1243 }
1244
1245 // Return the PLT address to use for a local symbol. These are always
1246 // IRELATIVE relocs.
1247
1248 uint64_t
1249 Output_data_plt_i386::address_for_local(const Relobj* object,
1250 unsigned int r_sym)
1251 {
1252 return (this->address()
1253 + (this->count_ + 1) * this->get_plt_entry_size()
1254 + object->local_plt_offset(r_sym));
1255 }
1256
1257 // The first entry in the PLT for an executable.
1258
1259 const unsigned char Output_data_plt_i386_exec::first_plt_entry[plt_entry_size] =
1260 {
1261 0xff, 0x35, // pushl contents of memory address
1262 0, 0, 0, 0, // replaced with address of .got + 4
1263 0xff, 0x25, // jmp indirect
1264 0, 0, 0, 0, // replaced with address of .got + 8
1265 0, 0, 0, 0 // unused
1266 };
1267
1268 void
1269 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1270 unsigned char* pov,
1271 elfcpp::Elf_types<32>::Elf_Addr got_address)
1272 {
1273 memcpy(pov, first_plt_entry, plt_entry_size);
1274 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1275 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1276 }
1277
1278 // The first entry in the PLT for a shared object.
1279
1280 const unsigned char Output_data_plt_i386_dyn::first_plt_entry[plt_entry_size] =
1281 {
1282 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1283 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1284 0, 0, 0, 0 // unused
1285 };
1286
1287 void
1288 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1289 unsigned char* pov,
1290 elfcpp::Elf_types<32>::Elf_Addr)
1291 {
1292 memcpy(pov, first_plt_entry, plt_entry_size);
1293 }
1294
1295 // Subsequent entries in the PLT for an executable.
1296
1297 const unsigned char Output_data_plt_i386_exec::plt_entry[plt_entry_size] =
1298 {
1299 0xff, 0x25, // jmp indirect
1300 0, 0, 0, 0, // replaced with address of symbol in .got
1301 0x68, // pushl immediate
1302 0, 0, 0, 0, // replaced with offset into relocation table
1303 0xe9, // jmp relative
1304 0, 0, 0, 0 // replaced with offset to start of .plt
1305 };
1306
1307 unsigned int
1308 Output_data_plt_i386_exec::do_fill_plt_entry(
1309 unsigned char* pov,
1310 elfcpp::Elf_types<32>::Elf_Addr got_address,
1311 unsigned int got_offset,
1312 unsigned int plt_offset,
1313 unsigned int plt_rel_offset)
1314 {
1315 memcpy(pov, plt_entry, plt_entry_size);
1316 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1317 got_address + got_offset);
1318 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1319 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1320 return 6;
1321 }
1322
1323 // Subsequent entries in the PLT for a shared object.
1324
1325 const unsigned char Output_data_plt_i386_dyn::plt_entry[plt_entry_size] =
1326 {
1327 0xff, 0xa3, // jmp *offset(%ebx)
1328 0, 0, 0, 0, // replaced with offset of symbol in .got
1329 0x68, // pushl immediate
1330 0, 0, 0, 0, // replaced with offset into relocation table
1331 0xe9, // jmp relative
1332 0, 0, 0, 0 // replaced with offset to start of .plt
1333 };
1334
1335 unsigned int
1336 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
1337 elfcpp::Elf_types<32>::Elf_Addr,
1338 unsigned int got_offset,
1339 unsigned int plt_offset,
1340 unsigned int plt_rel_offset)
1341 {
1342 memcpy(pov, plt_entry, plt_entry_size);
1343 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1344 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1345 elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
1346 return 6;
1347 }
1348
1349 // The .eh_frame unwind information for the PLT.
1350
1351 const unsigned char
1352 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1353 {
1354 1, // CIE version.
1355 'z', // Augmentation: augmentation size included.
1356 'R', // Augmentation: FDE encoding included.
1357 '\0', // End of augmentation string.
1358 1, // Code alignment factor.
1359 0x7c, // Data alignment factor.
1360 8, // Return address column.
1361 1, // Augmentation size.
1362 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
1363 | elfcpp::DW_EH_PE_sdata4),
1364 elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1365 elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1366 elfcpp::DW_CFA_nop, // Align to 16 bytes.
1367 elfcpp::DW_CFA_nop
1368 };
1369
1370 const unsigned char
1371 Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1372 {
1373 0, 0, 0, 0, // Replaced with offset to .plt.
1374 0, 0, 0, 0, // Replaced with size of .plt.
1375 0, // Augmentation size.
1376 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
1377 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
1378 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
1379 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
1380 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
1381 11, // Block length.
1382 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
1383 elfcpp::DW_OP_breg8, 0, // Push %eip.
1384 elfcpp::DW_OP_lit15, // Push 0xf.
1385 elfcpp::DW_OP_and, // & (%eip & 0xf).
1386 elfcpp::DW_OP_lit11, // Push 0xb.
1387 elfcpp::DW_OP_ge, // >= ((%eip & 0xf) >= 0xb)
1388 elfcpp::DW_OP_lit2, // Push 2.
1389 elfcpp::DW_OP_shl, // << (((%eip & 0xf) >= 0xb) << 2)
1390 elfcpp::DW_OP_plus, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1391 elfcpp::DW_CFA_nop, // Align to 32 bytes.
1392 elfcpp::DW_CFA_nop,
1393 elfcpp::DW_CFA_nop,
1394 elfcpp::DW_CFA_nop
1395 };
1396
1397 // Write out the PLT. This uses the hand-coded instructions above,
1398 // and adjusts them as needed. This is all specified by the i386 ELF
1399 // Processor Supplement.
1400
1401 void
1402 Output_data_plt_i386::do_write(Output_file* of)
1403 {
1404 const off_t offset = this->offset();
1405 const section_size_type oview_size =
1406 convert_to_section_size_type(this->data_size());
1407 unsigned char* const oview = of->get_output_view(offset, oview_size);
1408
1409 const off_t got_file_offset = this->got_plt_->offset();
1410 gold_assert(parameters->incremental_update()
1411 || (got_file_offset + this->got_plt_->data_size()
1412 == this->got_irelative_->offset()));
1413 const section_size_type got_size =
1414 convert_to_section_size_type(this->got_plt_->data_size()
1415 + this->got_irelative_->data_size());
1416
1417 unsigned char* const got_view = of->get_output_view(got_file_offset,
1418 got_size);
1419
1420 unsigned char* pov = oview;
1421
1422 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1423 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1424
1425 this->fill_first_plt_entry(pov, got_address);
1426 pov += this->get_plt_entry_size();
1427
1428 // The first three entries in the GOT are reserved, and are written
1429 // by Output_data_got_plt_i386::do_write.
1430 unsigned char* got_pov = got_view + 12;
1431
1432 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1433
1434 unsigned int plt_offset = this->get_plt_entry_size();
1435 unsigned int plt_rel_offset = 0;
1436 unsigned int got_offset = 12;
1437 const unsigned int count = this->count_ + this->irelative_count_;
1438 for (unsigned int i = 0;
1439 i < count;
1440 ++i,
1441 pov += this->get_plt_entry_size(),
1442 got_pov += 4,
1443 plt_offset += this->get_plt_entry_size(),
1444 plt_rel_offset += rel_size,
1445 got_offset += 4)
1446 {
1447 // Set and adjust the PLT entry itself.
1448 unsigned int lazy_offset = this->fill_plt_entry(pov,
1449 got_address,
1450 got_offset,
1451 plt_offset,
1452 plt_rel_offset);
1453
1454 // Set the entry in the GOT.
1455 elfcpp::Swap<32, false>::writeval(got_pov,
1456 plt_address + plt_offset + lazy_offset);
1457 }
1458
1459 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1460 // the GOT to point to the actual symbol value, rather than point to
1461 // the PLT entry. That will let the dynamic linker call the right
1462 // function when resolving IRELATIVE relocations.
1463 unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1464 for (std::vector<Global_ifunc>::const_iterator p =
1465 this->global_ifuncs_.begin();
1466 p != this->global_ifuncs_.end();
1467 ++p)
1468 {
1469 const Sized_symbol<32>* ssym =
1470 static_cast<const Sized_symbol<32>*>(p->sym);
1471 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1472 ssym->value());
1473 }
1474
1475 for (std::vector<Local_ifunc>::const_iterator p =
1476 this->local_ifuncs_.begin();
1477 p != this->local_ifuncs_.end();
1478 ++p)
1479 {
1480 const Symbol_value<32>* psymval =
1481 p->object->local_symbol(p->local_sym_index);
1482 elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1483 psymval->value(p->object, 0));
1484 }
1485
1486 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1487 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1488
1489 of->write_output_view(offset, oview_size, oview);
1490 of->write_output_view(got_file_offset, got_size, got_view);
1491 }
1492
1493 // Create the PLT section.
1494
1495 void
1496 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1497 {
1498 if (this->plt_ == NULL)
1499 {
1500 // Create the GOT sections first.
1501 this->got_section(symtab, layout);
1502
1503 const bool dyn = parameters->options().output_is_position_independent();
1504 this->plt_ = this->make_data_plt(layout,
1505 this->got_plt_,
1506 this->got_irelative_,
1507 dyn);
1508
1509 // Add unwind information if requested.
1510 if (parameters->options().ld_generated_unwind_info())
1511 this->plt_->add_eh_frame(layout);
1512
1513 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1514 (elfcpp::SHF_ALLOC
1515 | elfcpp::SHF_EXECINSTR),
1516 this->plt_, ORDER_PLT, false);
1517
1518 // Make the sh_info field of .rel.plt point to .plt.
1519 Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1520 rel_plt_os->set_info_section(this->plt_->output_section());
1521 }
1522 }
1523
1524 // Create a PLT entry for a global symbol.
1525
1526 void
1527 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1528 {
1529 if (gsym->has_plt_offset())
1530 return;
1531 if (this->plt_ == NULL)
1532 this->make_plt_section(symtab, layout);
1533 this->plt_->add_entry(symtab, layout, gsym);
1534 }
1535
1536 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1537
1538 void
1539 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1540 Sized_relobj_file<32, false>* relobj,
1541 unsigned int local_sym_index)
1542 {
1543 if (relobj->local_has_plt_offset(local_sym_index))
1544 return;
1545 if (this->plt_ == NULL)
1546 this->make_plt_section(symtab, layout);
1547 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1548 relobj,
1549 local_sym_index);
1550 relobj->set_local_plt_offset(local_sym_index, plt_offset);
1551 }
1552
1553 // Return the number of entries in the PLT.
1554
1555 unsigned int
1556 Target_i386::plt_entry_count() const
1557 {
1558 if (this->plt_ == NULL)
1559 return 0;
1560 return this->plt_->entry_count();
1561 }
1562
1563 // Return the offset of the first non-reserved PLT entry.
1564
1565 unsigned int
1566 Target_i386::first_plt_entry_offset() const
1567 {
1568 return this->plt_->first_plt_entry_offset();
1569 }
1570
1571 // Return the size of each PLT entry.
1572
1573 unsigned int
1574 Target_i386::plt_entry_size() const
1575 {
1576 return this->plt_->get_plt_entry_size();
1577 }
1578
1579 // Get the section to use for TLS_DESC relocations.
1580
1581 Target_i386::Reloc_section*
1582 Target_i386::rel_tls_desc_section(Layout* layout) const
1583 {
1584 return this->plt_section()->rel_tls_desc(layout);
1585 }
1586
1587 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1588
1589 void
1590 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1591 {
1592 if (this->tls_base_symbol_defined_)
1593 return;
1594
1595 Output_segment* tls_segment = layout->tls_segment();
1596 if (tls_segment != NULL)
1597 {
1598 bool is_exec = parameters->options().output_is_executable();
1599 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1600 Symbol_table::PREDEFINED,
1601 tls_segment, 0, 0,
1602 elfcpp::STT_TLS,
1603 elfcpp::STB_LOCAL,
1604 elfcpp::STV_HIDDEN, 0,
1605 (is_exec
1606 ? Symbol::SEGMENT_END
1607 : Symbol::SEGMENT_START),
1608 true);
1609 }
1610 this->tls_base_symbol_defined_ = true;
1611 }
1612
1613 // Create a GOT entry for the TLS module index.
1614
1615 unsigned int
1616 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1617 Sized_relobj_file<32, false>* object)
1618 {
1619 if (this->got_mod_index_offset_ == -1U)
1620 {
1621 gold_assert(symtab != NULL && layout != NULL && object != NULL);
1622 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1623 Output_data_got<32, false>* got = this->got_section(symtab, layout);
1624 unsigned int got_offset = got->add_constant(0);
1625 rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1626 got_offset);
1627 got->add_constant(0);
1628 this->got_mod_index_offset_ = got_offset;
1629 }
1630 return this->got_mod_index_offset_;
1631 }
1632
1633 // Optimize the TLS relocation type based on what we know about the
1634 // symbol. IS_FINAL is true if the final address of this symbol is
1635 // known at link time.
1636
1637 tls::Tls_optimization
1638 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1639 {
1640 // If we are generating a shared library, then we can't do anything
1641 // in the linker.
1642 if (parameters->options().shared())
1643 return tls::TLSOPT_NONE;
1644
1645 switch (r_type)
1646 {
1647 case elfcpp::R_386_TLS_GD:
1648 case elfcpp::R_386_TLS_GOTDESC:
1649 case elfcpp::R_386_TLS_DESC_CALL:
1650 // These are General-Dynamic which permits fully general TLS
1651 // access. Since we know that we are generating an executable,
1652 // we can convert this to Initial-Exec. If we also know that
1653 // this is a local symbol, we can further switch to Local-Exec.
1654 if (is_final)
1655 return tls::TLSOPT_TO_LE;
1656 return tls::TLSOPT_TO_IE;
1657
1658 case elfcpp::R_386_TLS_LDM:
1659 // This is Local-Dynamic, which refers to a local symbol in the
1660 // dynamic TLS block. Since we know that we generating an
1661 // executable, we can switch to Local-Exec.
1662 return tls::TLSOPT_TO_LE;
1663
1664 case elfcpp::R_386_TLS_LDO_32:
1665 // Another type of Local-Dynamic relocation.
1666 return tls::TLSOPT_TO_LE;
1667
1668 case elfcpp::R_386_TLS_IE:
1669 case elfcpp::R_386_TLS_GOTIE:
1670 case elfcpp::R_386_TLS_IE_32:
1671 // These are Initial-Exec relocs which get the thread offset
1672 // from the GOT. If we know that we are linking against the
1673 // local symbol, we can switch to Local-Exec, which links the
1674 // thread offset into the instruction.
1675 if (is_final)
1676 return tls::TLSOPT_TO_LE;
1677 return tls::TLSOPT_NONE;
1678
1679 case elfcpp::R_386_TLS_LE:
1680 case elfcpp::R_386_TLS_LE_32:
1681 // When we already have Local-Exec, there is nothing further we
1682 // can do.
1683 return tls::TLSOPT_NONE;
1684
1685 default:
1686 gold_unreachable();
1687 }
1688 }
1689
1690 // Get the Reference_flags for a particular relocation.
1691
1692 int
1693 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1694 {
1695 switch (r_type)
1696 {
1697 case elfcpp::R_386_NONE:
1698 case elfcpp::R_386_GNU_VTINHERIT:
1699 case elfcpp::R_386_GNU_VTENTRY:
1700 case elfcpp::R_386_GOTPC:
1701 // No symbol reference.
1702 return 0;
1703
1704 case elfcpp::R_386_32:
1705 case elfcpp::R_386_16:
1706 case elfcpp::R_386_8:
1707 return Symbol::ABSOLUTE_REF;
1708
1709 case elfcpp::R_386_PC32:
1710 case elfcpp::R_386_PC16:
1711 case elfcpp::R_386_PC8:
1712 case elfcpp::R_386_GOTOFF:
1713 return Symbol::RELATIVE_REF;
1714
1715 case elfcpp::R_386_PLT32:
1716 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1717
1718 case elfcpp::R_386_GOT32:
1719 case elfcpp::R_386_GOT32X:
1720 // Absolute in GOT.
1721 return Symbol::ABSOLUTE_REF;
1722
1723 case elfcpp::R_386_TLS_GD: // Global-dynamic
1724 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1725 case elfcpp::R_386_TLS_DESC_CALL:
1726 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1727 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1728 case elfcpp::R_386_TLS_IE: // Initial-exec
1729 case elfcpp::R_386_TLS_IE_32:
1730 case elfcpp::R_386_TLS_GOTIE:
1731 case elfcpp::R_386_TLS_LE: // Local-exec
1732 case elfcpp::R_386_TLS_LE_32:
1733 return Symbol::TLS_REF;
1734
1735 case elfcpp::R_386_COPY:
1736 case elfcpp::R_386_GLOB_DAT:
1737 case elfcpp::R_386_JUMP_SLOT:
1738 case elfcpp::R_386_RELATIVE:
1739 case elfcpp::R_386_IRELATIVE:
1740 case elfcpp::R_386_TLS_TPOFF:
1741 case elfcpp::R_386_TLS_DTPMOD32:
1742 case elfcpp::R_386_TLS_DTPOFF32:
1743 case elfcpp::R_386_TLS_TPOFF32:
1744 case elfcpp::R_386_TLS_DESC:
1745 case elfcpp::R_386_32PLT:
1746 case elfcpp::R_386_TLS_GD_32:
1747 case elfcpp::R_386_TLS_GD_PUSH:
1748 case elfcpp::R_386_TLS_GD_CALL:
1749 case elfcpp::R_386_TLS_GD_POP:
1750 case elfcpp::R_386_TLS_LDM_32:
1751 case elfcpp::R_386_TLS_LDM_PUSH:
1752 case elfcpp::R_386_TLS_LDM_CALL:
1753 case elfcpp::R_386_TLS_LDM_POP:
1754 case elfcpp::R_386_USED_BY_INTEL_200:
1755 default:
1756 // Not expected. We will give an error later.
1757 return 0;
1758 }
1759 }
1760
1761 // Report an unsupported relocation against a local symbol.
1762
1763 void
1764 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1765 unsigned int r_type)
1766 {
1767 gold_error(_("%s: unsupported reloc %u against local symbol"),
1768 object->name().c_str(), r_type);
1769 }
1770
1771 // Return whether we need to make a PLT entry for a relocation of a
1772 // given type against a STT_GNU_IFUNC symbol.
1773
1774 bool
1775 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1776 Sized_relobj_file<32, false>* object,
1777 unsigned int r_type)
1778 {
1779 int flags = Scan::get_reference_flags(r_type);
1780 if (flags & Symbol::TLS_REF)
1781 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1782 object->name().c_str(), r_type);
1783 return flags != 0;
1784 }
1785
1786 // Scan a relocation for a local symbol.
1787
1788 inline void
1789 Target_i386::Scan::local(Symbol_table* symtab,
1790 Layout* layout,
1791 Target_i386* target,
1792 Sized_relobj_file<32, false>* object,
1793 unsigned int data_shndx,
1794 Output_section* output_section,
1795 const elfcpp::Rel<32, false>& reloc,
1796 unsigned int r_type,
1797 const elfcpp::Sym<32, false>& lsym,
1798 bool is_discarded)
1799 {
1800 if (is_discarded)
1801 return;
1802
1803 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1804 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1805 && this->reloc_needs_plt_for_ifunc(object, r_type))
1806 {
1807 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1808 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1809 }
1810
1811 switch (r_type)
1812 {
1813 case elfcpp::R_386_NONE:
1814 case elfcpp::R_386_GNU_VTINHERIT:
1815 case elfcpp::R_386_GNU_VTENTRY:
1816 break;
1817
1818 case elfcpp::R_386_32:
1819 // If building a shared library (or a position-independent
1820 // executable), we need to create a dynamic relocation for
1821 // this location. The relocation applied at link time will
1822 // apply the link-time value, so we flag the location with
1823 // an R_386_RELATIVE relocation so the dynamic loader can
1824 // relocate it easily.
1825 if (parameters->options().output_is_position_independent())
1826 {
1827 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1828 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1829 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1830 output_section, data_shndx,
1831 reloc.get_r_offset());
1832 }
1833 break;
1834
1835 case elfcpp::R_386_16:
1836 case elfcpp::R_386_8:
1837 // If building a shared library (or a position-independent
1838 // executable), we need to create a dynamic relocation for
1839 // this location. Because the addend needs to remain in the
1840 // data section, we need to be careful not to apply this
1841 // relocation statically.
1842 if (parameters->options().output_is_position_independent())
1843 {
1844 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1845 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1846 if (lsym.get_st_type() != elfcpp::STT_SECTION)
1847 rel_dyn->add_local(object, r_sym, r_type, output_section,
1848 data_shndx, reloc.get_r_offset());
1849 else
1850 {
1851 gold_assert(lsym.get_st_value() == 0);
1852 unsigned int shndx = lsym.get_st_shndx();
1853 bool is_ordinary;
1854 shndx = object->adjust_sym_shndx(r_sym, shndx,
1855 &is_ordinary);
1856 if (!is_ordinary)
1857 object->error(_("section symbol %u has bad shndx %u"),
1858 r_sym, shndx);
1859 else
1860 rel_dyn->add_local_section(object, shndx,
1861 r_type, output_section,
1862 data_shndx, reloc.get_r_offset());
1863 }
1864 }
1865 break;
1866
1867 case elfcpp::R_386_PC32:
1868 case elfcpp::R_386_PC16:
1869 case elfcpp::R_386_PC8:
1870 break;
1871
1872 case elfcpp::R_386_PLT32:
1873 // Since we know this is a local symbol, we can handle this as a
1874 // PC32 reloc.
1875 break;
1876
1877 case elfcpp::R_386_GOTOFF:
1878 case elfcpp::R_386_GOTPC:
1879 // We need a GOT section.
1880 target->got_section(symtab, layout);
1881 break;
1882
1883 case elfcpp::R_386_GOT32:
1884 case elfcpp::R_386_GOT32X:
1885 {
1886 // We need GOT section.
1887 Output_data_got<32, false>* got = target->got_section(symtab, layout);
1888
1889 // If the relocation symbol isn't IFUNC,
1890 // and is local, then we will convert
1891 // mov foo@GOT(%reg), %reg
1892 // to
1893 // lea foo@GOTOFF(%reg), %reg
1894 // in Relocate::relocate.
1895 if (reloc.get_r_offset() >= 2
1896 && lsym.get_st_type() != elfcpp::STT_GNU_IFUNC)
1897 {
1898 section_size_type stype;
1899 const unsigned char* view = object->section_contents(data_shndx,
1900 &stype, true);
1901 if (view[reloc.get_r_offset() - 2] == 0x8b)
1902 break;
1903 }
1904
1905 // Otherwise, the symbol requires a GOT entry.
1906 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1907
1908 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1909 // lets function pointers compare correctly with shared
1910 // libraries. Otherwise we would need an IRELATIVE reloc.
1911 bool is_new;
1912 if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1913 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1914 else
1915 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1916 if (is_new)
1917 {
1918 // If we are generating a shared object, we need to add a
1919 // dynamic RELATIVE relocation for this symbol's GOT entry.
1920 if (parameters->options().output_is_position_independent())
1921 {
1922 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1923 unsigned int got_offset =
1924 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1925 rel_dyn->add_local_relative(object, r_sym,
1926 elfcpp::R_386_RELATIVE,
1927 got, got_offset);
1928 }
1929 }
1930 }
1931 break;
1932
1933 // These are relocations which should only be seen by the
1934 // dynamic linker, and should never be seen here.
1935 case elfcpp::R_386_COPY:
1936 case elfcpp::R_386_GLOB_DAT:
1937 case elfcpp::R_386_JUMP_SLOT:
1938 case elfcpp::R_386_RELATIVE:
1939 case elfcpp::R_386_IRELATIVE:
1940 case elfcpp::R_386_TLS_TPOFF:
1941 case elfcpp::R_386_TLS_DTPMOD32:
1942 case elfcpp::R_386_TLS_DTPOFF32:
1943 case elfcpp::R_386_TLS_TPOFF32:
1944 case elfcpp::R_386_TLS_DESC:
1945 gold_error(_("%s: unexpected reloc %u in object file"),
1946 object->name().c_str(), r_type);
1947 break;
1948
1949 // These are initial TLS relocs, which are expected when
1950 // linking.
1951 case elfcpp::R_386_TLS_GD: // Global-dynamic
1952 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
1953 case elfcpp::R_386_TLS_DESC_CALL:
1954 case elfcpp::R_386_TLS_LDM: // Local-dynamic
1955 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
1956 case elfcpp::R_386_TLS_IE: // Initial-exec
1957 case elfcpp::R_386_TLS_IE_32:
1958 case elfcpp::R_386_TLS_GOTIE:
1959 case elfcpp::R_386_TLS_LE: // Local-exec
1960 case elfcpp::R_386_TLS_LE_32:
1961 {
1962 bool output_is_shared = parameters->options().shared();
1963 const tls::Tls_optimization optimized_type
1964 = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1965 switch (r_type)
1966 {
1967 case elfcpp::R_386_TLS_GD: // Global-dynamic
1968 if (optimized_type == tls::TLSOPT_NONE)
1969 {
1970 // Create a pair of GOT entries for the module index and
1971 // dtv-relative offset.
1972 Output_data_got<32, false>* got
1973 = target->got_section(symtab, layout);
1974 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1975 unsigned int shndx = lsym.get_st_shndx();
1976 bool is_ordinary;
1977 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1978 if (!is_ordinary)
1979 object->error(_("local symbol %u has bad shndx %u"),
1980 r_sym, shndx);
1981 else
1982 got->add_local_pair_with_rel(object, r_sym, shndx,
1983 GOT_TYPE_TLS_PAIR,
1984 target->rel_dyn_section(layout),
1985 elfcpp::R_386_TLS_DTPMOD32);
1986 }
1987 else if (optimized_type != tls::TLSOPT_TO_LE)
1988 unsupported_reloc_local(object, r_type);
1989 break;
1990
1991 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
1992 target->define_tls_base_symbol(symtab, layout);
1993 if (optimized_type == tls::TLSOPT_NONE)
1994 {
1995 // Create a double GOT entry with an R_386_TLS_DESC
1996 // reloc. The R_386_TLS_DESC reloc is resolved
1997 // lazily, so the GOT entry needs to be in an area in
1998 // .got.plt, not .got. Call got_section to make sure
1999 // the section has been created.
2000 target->got_section(symtab, layout);
2001 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2002 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2003 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2004 {
2005 unsigned int got_offset = got->add_constant(0);
2006 // The local symbol value is stored in the second
2007 // GOT entry.
2008 got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
2009 // That set the GOT offset of the local symbol to
2010 // point to the second entry, but we want it to
2011 // point to the first.
2012 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2013 got_offset);
2014 Reloc_section* rt = target->rel_tls_desc_section(layout);
2015 rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
2016 }
2017 }
2018 else if (optimized_type != tls::TLSOPT_TO_LE)
2019 unsupported_reloc_local(object, r_type);
2020 break;
2021
2022 case elfcpp::R_386_TLS_DESC_CALL:
2023 break;
2024
2025 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2026 if (optimized_type == tls::TLSOPT_NONE)
2027 {
2028 // Create a GOT entry for the module index.
2029 target->got_mod_index_entry(symtab, layout, object);
2030 }
2031 else if (optimized_type != tls::TLSOPT_TO_LE)
2032 unsupported_reloc_local(object, r_type);
2033 break;
2034
2035 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2036 break;
2037
2038 case elfcpp::R_386_TLS_IE: // Initial-exec
2039 case elfcpp::R_386_TLS_IE_32:
2040 case elfcpp::R_386_TLS_GOTIE:
2041 layout->set_has_static_tls();
2042 if (optimized_type == tls::TLSOPT_NONE)
2043 {
2044 // For the R_386_TLS_IE relocation, we need to create a
2045 // dynamic relocation when building a shared library.
2046 if (r_type == elfcpp::R_386_TLS_IE
2047 && parameters->options().shared())
2048 {
2049 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2050 unsigned int r_sym
2051 = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2052 rel_dyn->add_local_relative(object, r_sym,
2053 elfcpp::R_386_RELATIVE,
2054 output_section, data_shndx,
2055 reloc.get_r_offset());
2056 }
2057 // Create a GOT entry for the tp-relative offset.
2058 Output_data_got<32, false>* got
2059 = target->got_section(symtab, layout);
2060 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2061 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2062 ? elfcpp::R_386_TLS_TPOFF32
2063 : elfcpp::R_386_TLS_TPOFF);
2064 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2065 ? GOT_TYPE_TLS_OFFSET
2066 : GOT_TYPE_TLS_NOFFSET);
2067 got->add_local_with_rel(object, r_sym, got_type,
2068 target->rel_dyn_section(layout),
2069 dyn_r_type);
2070 }
2071 else if (optimized_type != tls::TLSOPT_TO_LE)
2072 unsupported_reloc_local(object, r_type);
2073 break;
2074
2075 case elfcpp::R_386_TLS_LE: // Local-exec
2076 case elfcpp::R_386_TLS_LE_32:
2077 layout->set_has_static_tls();
2078 if (output_is_shared)
2079 {
2080 // We need to create a dynamic relocation.
2081 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2082 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
2083 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2084 ? elfcpp::R_386_TLS_TPOFF32
2085 : elfcpp::R_386_TLS_TPOFF);
2086 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2087 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
2088 data_shndx, reloc.get_r_offset());
2089 }
2090 break;
2091
2092 default:
2093 gold_unreachable();
2094 }
2095 }
2096 break;
2097
2098 case elfcpp::R_386_32PLT:
2099 case elfcpp::R_386_TLS_GD_32:
2100 case elfcpp::R_386_TLS_GD_PUSH:
2101 case elfcpp::R_386_TLS_GD_CALL:
2102 case elfcpp::R_386_TLS_GD_POP:
2103 case elfcpp::R_386_TLS_LDM_32:
2104 case elfcpp::R_386_TLS_LDM_PUSH:
2105 case elfcpp::R_386_TLS_LDM_CALL:
2106 case elfcpp::R_386_TLS_LDM_POP:
2107 case elfcpp::R_386_USED_BY_INTEL_200:
2108 default:
2109 unsupported_reloc_local(object, r_type);
2110 break;
2111 }
2112 }
2113
2114 // Report an unsupported relocation against a global symbol.
2115
2116 void
2117 Target_i386::Scan::unsupported_reloc_global(
2118 Sized_relobj_file<32, false>* object,
2119 unsigned int r_type,
2120 Symbol* gsym)
2121 {
2122 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2123 object->name().c_str(), r_type, gsym->demangled_name().c_str());
2124 }
2125
2126 inline bool
2127 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
2128 {
2129 switch (r_type)
2130 {
2131 case elfcpp::R_386_32:
2132 case elfcpp::R_386_16:
2133 case elfcpp::R_386_8:
2134 case elfcpp::R_386_GOTOFF:
2135 case elfcpp::R_386_GOT32:
2136 case elfcpp::R_386_GOT32X:
2137 {
2138 return true;
2139 }
2140 default:
2141 return false;
2142 }
2143 return false;
2144 }
2145
2146 inline bool
2147 Target_i386::Scan::local_reloc_may_be_function_pointer(
2148 Symbol_table* ,
2149 Layout* ,
2150 Target_i386* ,
2151 Sized_relobj_file<32, false>* ,
2152 unsigned int ,
2153 Output_section* ,
2154 const elfcpp::Rel<32, false>& ,
2155 unsigned int r_type,
2156 const elfcpp::Sym<32, false>&)
2157 {
2158 return possible_function_pointer_reloc(r_type);
2159 }
2160
2161 inline bool
2162 Target_i386::Scan::global_reloc_may_be_function_pointer(
2163 Symbol_table* ,
2164 Layout* ,
2165 Target_i386* ,
2166 Sized_relobj_file<32, false>* ,
2167 unsigned int ,
2168 Output_section* ,
2169 const elfcpp::Rel<32, false>& ,
2170 unsigned int r_type,
2171 Symbol*)
2172 {
2173 return possible_function_pointer_reloc(r_type);
2174 }
2175
2176 // Scan a relocation for a global symbol.
2177
2178 inline void
2179 Target_i386::Scan::global(Symbol_table* symtab,
2180 Layout* layout,
2181 Target_i386* target,
2182 Sized_relobj_file<32, false>* object,
2183 unsigned int data_shndx,
2184 Output_section* output_section,
2185 const elfcpp::Rel<32, false>& reloc,
2186 unsigned int r_type,
2187 Symbol* gsym)
2188 {
2189 // A STT_GNU_IFUNC symbol may require a PLT entry.
2190 if (gsym->type() == elfcpp::STT_GNU_IFUNC
2191 && this->reloc_needs_plt_for_ifunc(object, r_type))
2192 target->make_plt_entry(symtab, layout, gsym);
2193
2194 switch (r_type)
2195 {
2196 case elfcpp::R_386_NONE:
2197 case elfcpp::R_386_GNU_VTINHERIT:
2198 case elfcpp::R_386_GNU_VTENTRY:
2199 break;
2200
2201 case elfcpp::R_386_32:
2202 case elfcpp::R_386_16:
2203 case elfcpp::R_386_8:
2204 {
2205 // Make a PLT entry if necessary.
2206 if (gsym->needs_plt_entry())
2207 {
2208 target->make_plt_entry(symtab, layout, gsym);
2209 // Since this is not a PC-relative relocation, we may be
2210 // taking the address of a function. In that case we need to
2211 // set the entry in the dynamic symbol table to the address of
2212 // the PLT entry.
2213 if (gsym->is_from_dynobj() && !parameters->options().shared())
2214 gsym->set_needs_dynsym_value();
2215 }
2216 // Make a dynamic relocation if necessary.
2217 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2218 {
2219 if (!parameters->options().output_is_position_independent()
2220 && gsym->may_need_copy_reloc())
2221 {
2222 target->copy_reloc(symtab, layout, object,
2223 data_shndx, output_section, gsym, reloc);
2224 }
2225 else if (r_type == elfcpp::R_386_32
2226 && gsym->type() == elfcpp::STT_GNU_IFUNC
2227 && gsym->can_use_relative_reloc(false)
2228 && !gsym->is_from_dynobj()
2229 && !gsym->is_undefined()
2230 && !gsym->is_preemptible())
2231 {
2232 // Use an IRELATIVE reloc for a locally defined
2233 // STT_GNU_IFUNC symbol. This makes a function
2234 // address in a PIE executable match the address in a
2235 // shared library that it links against.
2236 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
2237 rel_dyn->add_symbolless_global_addend(gsym,
2238 elfcpp::R_386_IRELATIVE,
2239 output_section,
2240 object, data_shndx,
2241 reloc.get_r_offset());
2242 }
2243 else if (r_type == elfcpp::R_386_32
2244 && gsym->can_use_relative_reloc(false))
2245 {
2246 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2247 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2248 output_section, object,
2249 data_shndx, reloc.get_r_offset());
2250 }
2251 else
2252 {
2253 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2254 rel_dyn->add_global(gsym, r_type, output_section, object,
2255 data_shndx, reloc.get_r_offset());
2256 }
2257 }
2258 }
2259 break;
2260
2261 case elfcpp::R_386_PC32:
2262 case elfcpp::R_386_PC16:
2263 case elfcpp::R_386_PC8:
2264 {
2265 // Make a PLT entry if necessary.
2266 if (gsym->needs_plt_entry())
2267 {
2268 // These relocations are used for function calls only in
2269 // non-PIC code. For a 32-bit relocation in a shared library,
2270 // we'll need a text relocation anyway, so we can skip the
2271 // PLT entry and let the dynamic linker bind the call directly
2272 // to the target. For smaller relocations, we should use a
2273 // PLT entry to ensure that the call can reach.
2274 if (!parameters->options().shared()
2275 || r_type != elfcpp::R_386_PC32)
2276 target->make_plt_entry(symtab, layout, gsym);
2277 }
2278 // Make a dynamic relocation if necessary.
2279 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2280 {
2281 if (parameters->options().output_is_executable()
2282 && gsym->may_need_copy_reloc())
2283 {
2284 target->copy_reloc(symtab, layout, object,
2285 data_shndx, output_section, gsym, reloc);
2286 }
2287 else
2288 {
2289 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2290 rel_dyn->add_global(gsym, r_type, output_section, object,
2291 data_shndx, reloc.get_r_offset());
2292 }
2293 }
2294 }
2295 break;
2296
2297 case elfcpp::R_386_GOT32:
2298 case elfcpp::R_386_GOT32X:
2299 {
2300 // The symbol requires a GOT section.
2301 Output_data_got<32, false>* got = target->got_section(symtab, layout);
2302
2303 // If we convert this from
2304 // mov foo@GOT(%reg), %reg
2305 // to
2306 // lea foo@GOTOFF(%reg), %reg
2307 // in Relocate::relocate, then there is nothing to do here.
2308 if (reloc.get_r_offset() >= 2
2309 && Target_i386::can_convert_mov_to_lea(gsym))
2310 {
2311 section_size_type stype;
2312 const unsigned char* view = object->section_contents(data_shndx,
2313 &stype, true);
2314 if (view[reloc.get_r_offset() - 2] == 0x8b)
2315 break;
2316 }
2317
2318 if (gsym->final_value_is_known())
2319 {
2320 // For a STT_GNU_IFUNC symbol we want the PLT address.
2321 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2322 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2323 else
2324 got->add_global(gsym, GOT_TYPE_STANDARD);
2325 }
2326 else
2327 {
2328 // If this symbol is not fully resolved, we need to add a
2329 // GOT entry with a dynamic relocation.
2330 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2331
2332 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2333 //
2334 // 1) The symbol may be defined in some other module.
2335 //
2336 // 2) We are building a shared library and this is a
2337 // protected symbol; using GLOB_DAT means that the dynamic
2338 // linker can use the address of the PLT in the main
2339 // executable when appropriate so that function address
2340 // comparisons work.
2341 //
2342 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2343 // code, again so that function address comparisons work.
2344 if (gsym->is_from_dynobj()
2345 || gsym->is_undefined()
2346 || gsym->is_preemptible()
2347 || (gsym->visibility() == elfcpp::STV_PROTECTED
2348 && parameters->options().shared())
2349 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2350 && parameters->options().output_is_position_independent()))
2351 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2352 rel_dyn, elfcpp::R_386_GLOB_DAT);
2353 else
2354 {
2355 // For a STT_GNU_IFUNC symbol we want to write the PLT
2356 // offset into the GOT, so that function pointer
2357 // comparisons work correctly.
2358 bool is_new;
2359 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2360 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2361 else
2362 {
2363 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2364 // Tell the dynamic linker to use the PLT address
2365 // when resolving relocations.
2366 if (gsym->is_from_dynobj()
2367 && !parameters->options().shared())
2368 gsym->set_needs_dynsym_value();
2369 }
2370 if (is_new)
2371 {
2372 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2373 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2374 got, got_off);
2375 }
2376 }
2377 }
2378 }
2379 break;
2380
2381 case elfcpp::R_386_PLT32:
2382 // If the symbol is fully resolved, this is just a PC32 reloc.
2383 // Otherwise we need a PLT entry.
2384 if (gsym->final_value_is_known())
2385 break;
2386 // If building a shared library, we can also skip the PLT entry
2387 // if the symbol is defined in the output file and is protected
2388 // or hidden.
2389 if (gsym->is_defined()
2390 && !gsym->is_from_dynobj()
2391 && !gsym->is_preemptible())
2392 break;
2393 target->make_plt_entry(symtab, layout, gsym);
2394 break;
2395
2396 case elfcpp::R_386_GOTOFF:
2397 case elfcpp::R_386_GOTPC:
2398 // We need a GOT section.
2399 target->got_section(symtab, layout);
2400 break;
2401
2402 // These are relocations which should only be seen by the
2403 // dynamic linker, and should never be seen here.
2404 case elfcpp::R_386_COPY:
2405 case elfcpp::R_386_GLOB_DAT:
2406 case elfcpp::R_386_JUMP_SLOT:
2407 case elfcpp::R_386_RELATIVE:
2408 case elfcpp::R_386_IRELATIVE:
2409 case elfcpp::R_386_TLS_TPOFF:
2410 case elfcpp::R_386_TLS_DTPMOD32:
2411 case elfcpp::R_386_TLS_DTPOFF32:
2412 case elfcpp::R_386_TLS_TPOFF32:
2413 case elfcpp::R_386_TLS_DESC:
2414 gold_error(_("%s: unexpected reloc %u in object file"),
2415 object->name().c_str(), r_type);
2416 break;
2417
2418 // These are initial tls relocs, which are expected when
2419 // linking.
2420 case elfcpp::R_386_TLS_GD: // Global-dynamic
2421 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2422 case elfcpp::R_386_TLS_DESC_CALL:
2423 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2424 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2425 case elfcpp::R_386_TLS_IE: // Initial-exec
2426 case elfcpp::R_386_TLS_IE_32:
2427 case elfcpp::R_386_TLS_GOTIE:
2428 case elfcpp::R_386_TLS_LE: // Local-exec
2429 case elfcpp::R_386_TLS_LE_32:
2430 {
2431 const bool is_final = gsym->final_value_is_known();
2432 const tls::Tls_optimization optimized_type
2433 = Target_i386::optimize_tls_reloc(is_final, r_type);
2434 switch (r_type)
2435 {
2436 case elfcpp::R_386_TLS_GD: // Global-dynamic
2437 if (optimized_type == tls::TLSOPT_NONE)
2438 {
2439 // Create a pair of GOT entries for the module index and
2440 // dtv-relative offset.
2441 Output_data_got<32, false>* got
2442 = target->got_section(symtab, layout);
2443 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2444 target->rel_dyn_section(layout),
2445 elfcpp::R_386_TLS_DTPMOD32,
2446 elfcpp::R_386_TLS_DTPOFF32);
2447 }
2448 else if (optimized_type == tls::TLSOPT_TO_IE)
2449 {
2450 // Create a GOT entry for the tp-relative offset.
2451 Output_data_got<32, false>* got
2452 = target->got_section(symtab, layout);
2453 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2454 target->rel_dyn_section(layout),
2455 elfcpp::R_386_TLS_TPOFF);
2456 }
2457 else if (optimized_type != tls::TLSOPT_TO_LE)
2458 unsupported_reloc_global(object, r_type, gsym);
2459 break;
2460
2461 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
2462 target->define_tls_base_symbol(symtab, layout);
2463 if (optimized_type == tls::TLSOPT_NONE)
2464 {
2465 // Create a double GOT entry with an R_386_TLS_DESC
2466 // reloc. The R_386_TLS_DESC reloc is resolved
2467 // lazily, so the GOT entry needs to be in an area in
2468 // .got.plt, not .got. Call got_section to make sure
2469 // the section has been created.
2470 target->got_section(symtab, layout);
2471 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2472 Reloc_section* rt = target->rel_tls_desc_section(layout);
2473 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2474 elfcpp::R_386_TLS_DESC, 0);
2475 }
2476 else if (optimized_type == tls::TLSOPT_TO_IE)
2477 {
2478 // Create a GOT entry for the tp-relative offset.
2479 Output_data_got<32, false>* got
2480 = target->got_section(symtab, layout);
2481 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2482 target->rel_dyn_section(layout),
2483 elfcpp::R_386_TLS_TPOFF);
2484 }
2485 else if (optimized_type != tls::TLSOPT_TO_LE)
2486 unsupported_reloc_global(object, r_type, gsym);
2487 break;
2488
2489 case elfcpp::R_386_TLS_DESC_CALL:
2490 break;
2491
2492 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2493 if (optimized_type == tls::TLSOPT_NONE)
2494 {
2495 // Create a GOT entry for the module index.
2496 target->got_mod_index_entry(symtab, layout, object);
2497 }
2498 else if (optimized_type != tls::TLSOPT_TO_LE)
2499 unsupported_reloc_global(object, r_type, gsym);
2500 break;
2501
2502 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2503 break;
2504
2505 case elfcpp::R_386_TLS_IE: // Initial-exec
2506 case elfcpp::R_386_TLS_IE_32:
2507 case elfcpp::R_386_TLS_GOTIE:
2508 layout->set_has_static_tls();
2509 if (optimized_type == tls::TLSOPT_NONE)
2510 {
2511 // For the R_386_TLS_IE relocation, we need to create a
2512 // dynamic relocation when building a shared library.
2513 if (r_type == elfcpp::R_386_TLS_IE
2514 && parameters->options().shared())
2515 {
2516 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2517 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2518 output_section, object,
2519 data_shndx,
2520 reloc.get_r_offset());
2521 }
2522 // Create a GOT entry for the tp-relative offset.
2523 Output_data_got<32, false>* got
2524 = target->got_section(symtab, layout);
2525 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2526 ? elfcpp::R_386_TLS_TPOFF32
2527 : elfcpp::R_386_TLS_TPOFF);
2528 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2529 ? GOT_TYPE_TLS_OFFSET
2530 : GOT_TYPE_TLS_NOFFSET);
2531 got->add_global_with_rel(gsym, got_type,
2532 target->rel_dyn_section(layout),
2533 dyn_r_type);
2534 }
2535 else if (optimized_type != tls::TLSOPT_TO_LE)
2536 unsupported_reloc_global(object, r_type, gsym);
2537 break;
2538
2539 case elfcpp::R_386_TLS_LE: // Local-exec
2540 case elfcpp::R_386_TLS_LE_32:
2541 layout->set_has_static_tls();
2542 if (parameters->options().shared())
2543 {
2544 // We need to create a dynamic relocation.
2545 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2546 ? elfcpp::R_386_TLS_TPOFF32
2547 : elfcpp::R_386_TLS_TPOFF);
2548 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2549 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2550 data_shndx, reloc.get_r_offset());
2551 }
2552 break;
2553
2554 default:
2555 gold_unreachable();
2556 }
2557 }
2558 break;
2559
2560 case elfcpp::R_386_32PLT:
2561 case elfcpp::R_386_TLS_GD_32:
2562 case elfcpp::R_386_TLS_GD_PUSH:
2563 case elfcpp::R_386_TLS_GD_CALL:
2564 case elfcpp::R_386_TLS_GD_POP:
2565 case elfcpp::R_386_TLS_LDM_32:
2566 case elfcpp::R_386_TLS_LDM_PUSH:
2567 case elfcpp::R_386_TLS_LDM_CALL:
2568 case elfcpp::R_386_TLS_LDM_POP:
2569 case elfcpp::R_386_USED_BY_INTEL_200:
2570 default:
2571 unsupported_reloc_global(object, r_type, gsym);
2572 break;
2573 }
2574 }
2575
2576 // Process relocations for gc.
2577
2578 void
2579 Target_i386::gc_process_relocs(Symbol_table* symtab,
2580 Layout* layout,
2581 Sized_relobj_file<32, false>* object,
2582 unsigned int data_shndx,
2583 unsigned int,
2584 const unsigned char* prelocs,
2585 size_t reloc_count,
2586 Output_section* output_section,
2587 bool needs_special_offset_handling,
2588 size_t local_symbol_count,
2589 const unsigned char* plocal_symbols)
2590 {
2591 gold::gc_process_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2592 symtab,
2593 layout,
2594 this,
2595 object,
2596 data_shndx,
2597 prelocs,
2598 reloc_count,
2599 output_section,
2600 needs_special_offset_handling,
2601 local_symbol_count,
2602 plocal_symbols);
2603 }
2604
2605 // Scan relocations for a section.
2606
2607 void
2608 Target_i386::scan_relocs(Symbol_table* symtab,
2609 Layout* layout,
2610 Sized_relobj_file<32, false>* object,
2611 unsigned int data_shndx,
2612 unsigned int sh_type,
2613 const unsigned char* prelocs,
2614 size_t reloc_count,
2615 Output_section* output_section,
2616 bool needs_special_offset_handling,
2617 size_t local_symbol_count,
2618 const unsigned char* plocal_symbols)
2619 {
2620 if (sh_type == elfcpp::SHT_RELA)
2621 {
2622 gold_error(_("%s: unsupported RELA reloc section"),
2623 object->name().c_str());
2624 return;
2625 }
2626
2627 gold::scan_relocs<32, false, Target_i386, Scan, Classify_reloc>(
2628 symtab,
2629 layout,
2630 this,
2631 object,
2632 data_shndx,
2633 prelocs,
2634 reloc_count,
2635 output_section,
2636 needs_special_offset_handling,
2637 local_symbol_count,
2638 plocal_symbols);
2639 }
2640
2641 // Finalize the sections.
2642
2643 void
2644 Target_i386::do_finalize_sections(
2645 Layout* layout,
2646 const Input_objects*,
2647 Symbol_table* symtab)
2648 {
2649 const Reloc_section* rel_plt = (this->plt_ == NULL
2650 ? NULL
2651 : this->plt_->rel_plt());
2652 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2653 this->rel_dyn_, true, false);
2654
2655 // Emit any relocs we saved in an attempt to avoid generating COPY
2656 // relocs.
2657 if (this->copy_relocs_.any_saved_relocs())
2658 this->copy_relocs_.emit(this->rel_dyn_section(layout));
2659
2660 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2661 // the .got.plt section.
2662 Symbol* sym = this->global_offset_table_;
2663 if (sym != NULL)
2664 {
2665 uint32_t data_size = this->got_plt_->current_data_size();
2666 symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2667 }
2668
2669 if (parameters->doing_static_link()
2670 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2671 {
2672 // If linking statically, make sure that the __rel_iplt symbols
2673 // were defined if necessary, even if we didn't create a PLT.
2674 static const Define_symbol_in_segment syms[] =
2675 {
2676 {
2677 "__rel_iplt_start", // name
2678 elfcpp::PT_LOAD, // segment_type
2679 elfcpp::PF_W, // segment_flags_set
2680 elfcpp::PF(0), // segment_flags_clear
2681 0, // value
2682 0, // size
2683 elfcpp::STT_NOTYPE, // type
2684 elfcpp::STB_GLOBAL, // binding
2685 elfcpp::STV_HIDDEN, // visibility
2686 0, // nonvis
2687 Symbol::SEGMENT_START, // offset_from_base
2688 true // only_if_ref
2689 },
2690 {
2691 "__rel_iplt_end", // name
2692 elfcpp::PT_LOAD, // segment_type
2693 elfcpp::PF_W, // segment_flags_set
2694 elfcpp::PF(0), // segment_flags_clear
2695 0, // value
2696 0, // size
2697 elfcpp::STT_NOTYPE, // type
2698 elfcpp::STB_GLOBAL, // binding
2699 elfcpp::STV_HIDDEN, // visibility
2700 0, // nonvis
2701 Symbol::SEGMENT_START, // offset_from_base
2702 true // only_if_ref
2703 }
2704 };
2705
2706 symtab->define_symbols(layout, 2, syms,
2707 layout->script_options()->saw_sections_clause());
2708 }
2709 }
2710
2711 // Return whether a direct absolute static relocation needs to be applied.
2712 // In cases where Scan::local() or Scan::global() has created
2713 // a dynamic relocation other than R_386_RELATIVE, the addend
2714 // of the relocation is carried in the data, and we must not
2715 // apply the static relocation.
2716
2717 inline bool
2718 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2719 unsigned int r_type,
2720 bool is_32bit,
2721 Output_section* output_section)
2722 {
2723 // If the output section is not allocated, then we didn't call
2724 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2725 // the reloc here.
2726 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2727 return true;
2728
2729 int ref_flags = Scan::get_reference_flags(r_type);
2730
2731 // For local symbols, we will have created a non-RELATIVE dynamic
2732 // relocation only if (a) the output is position independent,
2733 // (b) the relocation is absolute (not pc- or segment-relative), and
2734 // (c) the relocation is not 32 bits wide.
2735 if (gsym == NULL)
2736 return !(parameters->options().output_is_position_independent()
2737 && (ref_flags & Symbol::ABSOLUTE_REF)
2738 && !is_32bit);
2739
2740 // For global symbols, we use the same helper routines used in the
2741 // scan pass. If we did not create a dynamic relocation, or if we
2742 // created a RELATIVE dynamic relocation, we should apply the static
2743 // relocation.
2744 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2745 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2746 && gsym->can_use_relative_reloc(ref_flags
2747 & Symbol::FUNCTION_CALL);
2748 return !has_dyn || is_rel;
2749 }
2750
2751 // Perform a relocation.
2752
2753 inline bool
2754 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2755 unsigned int,
2756 Target_i386* target,
2757 Output_section* output_section,
2758 size_t relnum,
2759 const unsigned char* preloc,
2760 const Sized_symbol<32>* gsym,
2761 const Symbol_value<32>* psymval,
2762 unsigned char* view,
2763 elfcpp::Elf_types<32>::Elf_Addr address,
2764 section_size_type view_size)
2765 {
2766 const elfcpp::Rel<32, false> rel(preloc);
2767 unsigned int r_type = elfcpp::elf_r_type<32>(rel.get_r_info());
2768
2769 if (this->skip_call_tls_get_addr_)
2770 {
2771 if ((r_type != elfcpp::R_386_PLT32
2772 && r_type != elfcpp::R_386_PC32)
2773 || gsym == NULL
2774 || strcmp(gsym->name(), "___tls_get_addr") != 0)
2775 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2776 _("missing expected TLS relocation"));
2777 else
2778 {
2779 this->skip_call_tls_get_addr_ = false;
2780 return false;
2781 }
2782 }
2783
2784 if (view == NULL)
2785 return true;
2786
2787 const Sized_relobj_file<32, false>* object = relinfo->object;
2788
2789 // Pick the value to use for symbols defined in shared objects.
2790 Symbol_value<32> symval;
2791 if (gsym != NULL
2792 && gsym->type() == elfcpp::STT_GNU_IFUNC
2793 && r_type == elfcpp::R_386_32
2794 && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2795 && gsym->can_use_relative_reloc(false)
2796 && !gsym->is_from_dynobj()
2797 && !gsym->is_undefined()
2798 && !gsym->is_preemptible())
2799 {
2800 // In this case we are generating a R_386_IRELATIVE reloc. We
2801 // want to use the real value of the symbol, not the PLT offset.
2802 }
2803 else if (gsym != NULL
2804 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2805 {
2806 symval.set_output_value(target->plt_address_for_global(gsym));
2807 psymval = &symval;
2808 }
2809 else if (gsym == NULL && psymval->is_ifunc_symbol())
2810 {
2811 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2812 if (object->local_has_plt_offset(r_sym))
2813 {
2814 symval.set_output_value(target->plt_address_for_local(object, r_sym));
2815 psymval = &symval;
2816 }
2817 }
2818
2819 bool baseless;
2820
2821 switch (r_type)
2822 {
2823 case elfcpp::R_386_NONE:
2824 case elfcpp::R_386_GNU_VTINHERIT:
2825 case elfcpp::R_386_GNU_VTENTRY:
2826 break;
2827
2828 case elfcpp::R_386_32:
2829 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2830 Relocate_functions<32, false>::rel32(view, object, psymval);
2831 break;
2832
2833 case elfcpp::R_386_PC32:
2834 if (should_apply_static_reloc(gsym, r_type, true, output_section))
2835 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2836 break;
2837
2838 case elfcpp::R_386_16:
2839 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2840 Relocate_functions<32, false>::rel16(view, object, psymval);
2841 break;
2842
2843 case elfcpp::R_386_PC16:
2844 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2845 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2846 break;
2847
2848 case elfcpp::R_386_8:
2849 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2850 Relocate_functions<32, false>::rel8(view, object, psymval);
2851 break;
2852
2853 case elfcpp::R_386_PC8:
2854 if (should_apply_static_reloc(gsym, r_type, false, output_section))
2855 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2856 break;
2857
2858 case elfcpp::R_386_PLT32:
2859 gold_assert(gsym == NULL
2860 || gsym->has_plt_offset()
2861 || gsym->final_value_is_known()
2862 || (gsym->is_defined()
2863 && !gsym->is_from_dynobj()
2864 && !gsym->is_preemptible()));
2865 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2866 break;
2867
2868 case elfcpp::R_386_GOT32:
2869 case elfcpp::R_386_GOT32X:
2870 baseless = (view[-1] & 0xc7) == 0x5;
2871 // R_386_GOT32 and R_386_GOT32X don't work without base register
2872 // when generating a position-independent output file.
2873 if (baseless
2874 && parameters->options().output_is_position_independent())
2875 {
2876 if(gsym)
2877 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2878 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2879 r_type, gsym->demangled_name().c_str());
2880 else
2881 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2882 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2883 r_type);
2884 }
2885
2886 // Convert
2887 // mov foo@GOT(%reg), %reg
2888 // to
2889 // lea foo@GOTOFF(%reg), %reg
2890 // if possible.
2891 if (rel.get_r_offset() >= 2
2892 && view[-2] == 0x8b
2893 && ((gsym == NULL && !psymval->is_ifunc_symbol())
2894 || (gsym != NULL
2895 && Target_i386::can_convert_mov_to_lea(gsym))))
2896 {
2897 view[-2] = 0x8d;
2898 elfcpp::Elf_types<32>::Elf_Addr value;
2899 value = psymval->value(object, 0);
2900 // Don't subtract the .got.plt section address for baseless
2901 // addressing.
2902 if (!baseless)
2903 value -= target->got_plt_section()->address();
2904 Relocate_functions<32, false>::rel32(view, value);
2905 }
2906 else
2907 {
2908 // The GOT pointer points to the end of the GOT section.
2909 // We need to subtract the size of the GOT section to get
2910 // the actual offset to use in the relocation.
2911 unsigned int got_offset = 0;
2912 if (gsym != NULL)
2913 {
2914 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2915 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2916 - target->got_size());
2917 }
2918 else
2919 {
2920 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2921 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2922 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2923 - target->got_size());
2924 }
2925 // Add the .got.plt section address for baseless addressing.
2926 if (baseless)
2927 got_offset += target->got_plt_section()->address();
2928 Relocate_functions<32, false>::rel32(view, got_offset);
2929 }
2930 break;
2931
2932 case elfcpp::R_386_GOTOFF:
2933 {
2934 elfcpp::Elf_types<32>::Elf_Addr value;
2935 value = (psymval->value(object, 0)
2936 - target->got_plt_section()->address());
2937 Relocate_functions<32, false>::rel32(view, value);
2938 }
2939 break;
2940
2941 case elfcpp::R_386_GOTPC:
2942 {
2943 elfcpp::Elf_types<32>::Elf_Addr value;
2944 value = target->got_plt_section()->address();
2945 Relocate_functions<32, false>::pcrel32(view, value, address);
2946 }
2947 break;
2948
2949 case elfcpp::R_386_COPY:
2950 case elfcpp::R_386_GLOB_DAT:
2951 case elfcpp::R_386_JUMP_SLOT:
2952 case elfcpp::R_386_RELATIVE:
2953 case elfcpp::R_386_IRELATIVE:
2954 // These are outstanding tls relocs, which are unexpected when
2955 // linking.
2956 case elfcpp::R_386_TLS_TPOFF:
2957 case elfcpp::R_386_TLS_DTPMOD32:
2958 case elfcpp::R_386_TLS_DTPOFF32:
2959 case elfcpp::R_386_TLS_TPOFF32:
2960 case elfcpp::R_386_TLS_DESC:
2961 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2962 _("unexpected reloc %u in object file"),
2963 r_type);
2964 break;
2965
2966 // These are initial tls relocs, which are expected when
2967 // linking.
2968 case elfcpp::R_386_TLS_GD: // Global-dynamic
2969 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
2970 case elfcpp::R_386_TLS_DESC_CALL:
2971 case elfcpp::R_386_TLS_LDM: // Local-dynamic
2972 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
2973 case elfcpp::R_386_TLS_IE: // Initial-exec
2974 case elfcpp::R_386_TLS_IE_32:
2975 case elfcpp::R_386_TLS_GOTIE:
2976 case elfcpp::R_386_TLS_LE: // Local-exec
2977 case elfcpp::R_386_TLS_LE_32:
2978 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2979 view, address, view_size);
2980 break;
2981
2982 case elfcpp::R_386_32PLT:
2983 case elfcpp::R_386_TLS_GD_32:
2984 case elfcpp::R_386_TLS_GD_PUSH:
2985 case elfcpp::R_386_TLS_GD_CALL:
2986 case elfcpp::R_386_TLS_GD_POP:
2987 case elfcpp::R_386_TLS_LDM_32:
2988 case elfcpp::R_386_TLS_LDM_PUSH:
2989 case elfcpp::R_386_TLS_LDM_CALL:
2990 case elfcpp::R_386_TLS_LDM_POP:
2991 case elfcpp::R_386_USED_BY_INTEL_200:
2992 default:
2993 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2994 _("unsupported reloc %u"),
2995 r_type);
2996 break;
2997 }
2998
2999 return true;
3000 }
3001
3002 // Perform a TLS relocation.
3003
3004 inline void
3005 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
3006 Target_i386* target,
3007 size_t relnum,
3008 const elfcpp::Rel<32, false>& rel,
3009 unsigned int r_type,
3010 const Sized_symbol<32>* gsym,
3011 const Symbol_value<32>* psymval,
3012 unsigned char* view,
3013 elfcpp::Elf_types<32>::Elf_Addr,
3014 section_size_type view_size)
3015 {
3016 Output_segment* tls_segment = relinfo->layout->tls_segment();
3017
3018 const Sized_relobj_file<32, false>* object = relinfo->object;
3019
3020 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
3021
3022 const bool is_final = (gsym == NULL
3023 ? !parameters->options().shared()
3024 : gsym->final_value_is_known());
3025 const tls::Tls_optimization optimized_type
3026 = Target_i386::optimize_tls_reloc(is_final, r_type);
3027 switch (r_type)
3028 {
3029 case elfcpp::R_386_TLS_GD: // Global-dynamic
3030 if (optimized_type == tls::TLSOPT_TO_LE)
3031 {
3032 if (tls_segment == NULL)
3033 {
3034 gold_assert(parameters->errors()->error_count() > 0
3035 || issue_undefined_symbol_error(gsym));
3036 return;
3037 }
3038 this->tls_gd_to_le(relinfo, relnum, tls_segment,
3039 rel, r_type, value, view,
3040 view_size);
3041 break;
3042 }
3043 else
3044 {
3045 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3046 ? GOT_TYPE_TLS_NOFFSET
3047 : GOT_TYPE_TLS_PAIR);
3048 unsigned int got_offset;
3049 if (gsym != NULL)
3050 {
3051 gold_assert(gsym->has_got_offset(got_type));
3052 got_offset = gsym->got_offset(got_type) - target->got_size();
3053 }
3054 else
3055 {
3056 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3057 gold_assert(object->local_has_got_offset(r_sym, got_type));
3058 got_offset = (object->local_got_offset(r_sym, got_type)
3059 - target->got_size());
3060 }
3061 if (optimized_type == tls::TLSOPT_TO_IE)
3062 {
3063 this->tls_gd_to_ie(relinfo, relnum, rel, r_type,
3064 got_offset, view, view_size);
3065 break;
3066 }
3067 else if (optimized_type == tls::TLSOPT_NONE)
3068 {
3069 // Relocate the field with the offset of the pair of GOT
3070 // entries.
3071 Relocate_functions<32, false>::rel32(view, got_offset);
3072 break;
3073 }
3074 }
3075 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3076 _("unsupported reloc %u"),
3077 r_type);
3078 break;
3079
3080 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3081 case elfcpp::R_386_TLS_DESC_CALL:
3082 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3083 if (optimized_type == tls::TLSOPT_TO_LE)
3084 {
3085 if (tls_segment == NULL)
3086 {
3087 gold_assert(parameters->errors()->error_count() > 0
3088 || issue_undefined_symbol_error(gsym));
3089 return;
3090 }
3091 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3092 rel, r_type, value, view,
3093 view_size);
3094 break;
3095 }
3096 else
3097 {
3098 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3099 ? GOT_TYPE_TLS_NOFFSET
3100 : GOT_TYPE_TLS_DESC);
3101 unsigned int got_offset = 0;
3102 if (r_type == elfcpp::R_386_TLS_GOTDESC
3103 && optimized_type == tls::TLSOPT_NONE)
3104 {
3105 // We created GOT entries in the .got.tlsdesc portion of
3106 // the .got.plt section, but the offset stored in the
3107 // symbol is the offset within .got.tlsdesc.
3108 got_offset = (target->got_size()
3109 + target->got_plt_section()->data_size());
3110 }
3111 if (gsym != NULL)
3112 {
3113 gold_assert(gsym->has_got_offset(got_type));
3114 got_offset += gsym->got_offset(got_type) - target->got_size();
3115 }
3116 else
3117 {
3118 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3119 gold_assert(object->local_has_got_offset(r_sym, got_type));
3120 got_offset += (object->local_got_offset(r_sym, got_type)
3121 - target->got_size());
3122 }
3123 if (optimized_type == tls::TLSOPT_TO_IE)
3124 {
3125 this->tls_desc_gd_to_ie(relinfo, relnum, rel, r_type,
3126 got_offset, view, view_size);
3127 break;
3128 }
3129 else if (optimized_type == tls::TLSOPT_NONE)
3130 {
3131 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3132 {
3133 // Relocate the field with the offset of the pair of GOT
3134 // entries.
3135 Relocate_functions<32, false>::rel32(view, got_offset);
3136 }
3137 break;
3138 }
3139 }
3140 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3141 _("unsupported reloc %u"),
3142 r_type);
3143 break;
3144
3145 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3146 if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
3147 {
3148 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3149 _("both SUN and GNU model "
3150 "TLS relocations"));
3151 break;
3152 }
3153 this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
3154 if (optimized_type == tls::TLSOPT_TO_LE)
3155 {
3156 if (tls_segment == NULL)
3157 {
3158 gold_assert(parameters->errors()->error_count() > 0
3159 || issue_undefined_symbol_error(gsym));
3160 return;
3161 }
3162 this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
3163 value, view, view_size);
3164 break;
3165 }
3166 else if (optimized_type == tls::TLSOPT_NONE)
3167 {
3168 // Relocate the field with the offset of the GOT entry for
3169 // the module index.
3170 unsigned int got_offset;
3171 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3172 - target->got_size());
3173 Relocate_functions<32, false>::rel32(view, got_offset);
3174 break;
3175 }
3176 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3177 _("unsupported reloc %u"),
3178 r_type);
3179 break;
3180
3181 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3182 if (optimized_type == tls::TLSOPT_TO_LE)
3183 {
3184 // This reloc can appear in debugging sections, in which
3185 // case we must not convert to local-exec. We decide what
3186 // to do based on whether the section is marked as
3187 // containing executable code. That is what the GNU linker
3188 // does as well.
3189 elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
3190 if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
3191 {
3192 if (tls_segment == NULL)
3193 {
3194 gold_assert(parameters->errors()->error_count() > 0
3195 || issue_undefined_symbol_error(gsym));
3196 return;
3197 }
3198 value -= tls_segment->memsz();
3199 }
3200 }
3201 Relocate_functions<32, false>::rel32(view, value);
3202 break;
3203
3204 case elfcpp::R_386_TLS_IE: // Initial-exec
3205 case elfcpp::R_386_TLS_GOTIE:
3206 case elfcpp::R_386_TLS_IE_32:
3207 if (optimized_type == tls::TLSOPT_TO_LE)
3208 {
3209 if (tls_segment == NULL)
3210 {
3211 gold_assert(parameters->errors()->error_count() > 0
3212 || issue_undefined_symbol_error(gsym));
3213 return;
3214 }
3215 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3216 rel, r_type, value, view,
3217 view_size);
3218 break;
3219 }
3220 else if (optimized_type == tls::TLSOPT_NONE)
3221 {
3222 // Relocate the field with the offset of the GOT entry for
3223 // the tp-relative offset of the symbol.
3224 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
3225 ? GOT_TYPE_TLS_OFFSET
3226 : GOT_TYPE_TLS_NOFFSET);
3227 unsigned int got_offset;
3228 if (gsym != NULL)
3229 {
3230 gold_assert(gsym->has_got_offset(got_type));
3231 got_offset = gsym->got_offset(got_type);
3232 }
3233 else
3234 {
3235 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
3236 gold_assert(object->local_has_got_offset(r_sym, got_type));
3237 got_offset = object->local_got_offset(r_sym, got_type);
3238 }
3239 // For the R_386_TLS_IE relocation, we need to apply the
3240 // absolute address of the GOT entry.
3241 if (r_type == elfcpp::R_386_TLS_IE)
3242 got_offset += target->got_plt_section()->address();
3243 // All GOT offsets are relative to the end of the GOT.
3244 got_offset -= target->got_size();
3245 Relocate_functions<32, false>::rel32(view, got_offset);
3246 break;
3247 }
3248 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
3249 _("unsupported reloc %u"),
3250 r_type);
3251 break;
3252
3253 case elfcpp::R_386_TLS_LE: // Local-exec
3254 // If we're creating a shared library, a dynamic relocation will
3255 // have been created for this location, so do not apply it now.
3256 if (!parameters->options().shared())
3257 {
3258 if (tls_segment == NULL)
3259 {
3260 gold_assert(parameters->errors()->error_count() > 0
3261 || issue_undefined_symbol_error(gsym));
3262 return;
3263 }
3264 value -= tls_segment->memsz();
3265 Relocate_functions<32, false>::rel32(view, value);
3266 }
3267 break;
3268
3269 case elfcpp::R_386_TLS_LE_32:
3270 // If we're creating a shared library, a dynamic relocation will
3271 // have been created for this location, so do not apply it now.
3272 if (!parameters->options().shared())
3273 {
3274 if (tls_segment == NULL)
3275 {
3276 gold_assert(parameters->errors()->error_count() > 0
3277 || issue_undefined_symbol_error(gsym));
3278 return;
3279 }
3280 value = tls_segment->memsz() - value;
3281 Relocate_functions<32, false>::rel32(view, value);
3282 }
3283 break;
3284 }
3285 }
3286
3287 // Do a relocation in which we convert a TLS General-Dynamic to a
3288 // Local-Exec.
3289
3290 inline void
3291 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
3292 size_t relnum,
3293 Output_segment* tls_segment,
3294 const elfcpp::Rel<32, false>& rel,
3295 unsigned int,
3296 elfcpp::Elf_types<32>::Elf_Addr value,
3297 unsigned char* view,
3298 section_size_type view_size)
3299 {
3300 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3301 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3302 // leal foo(%reg),%eax; call ___tls_get_addr
3303 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3304
3305 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3306 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3307
3308 unsigned char op1 = view[-1];
3309 unsigned char op2 = view[-2];
3310
3311 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3312 op2 == 0x8d || op2 == 0x04);
3313 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3314
3315 int roff = 5;
3316
3317 if (op2 == 0x04)
3318 {
3319 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3320 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3321 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3322 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3323 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3324 }
3325 else
3326 {
3327 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3328 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3329 if (rel.get_r_offset() + 9 < view_size
3330 && view[9] == 0x90)
3331 {
3332 // There is a trailing nop. Use the size byte subl.
3333 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3334 roff = 6;
3335 }
3336 else
3337 {
3338 // Use the five byte subl.
3339 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3340 }
3341 }
3342
3343 value = tls_segment->memsz() - value;
3344 Relocate_functions<32, false>::rel32(view + roff, value);
3345
3346 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3347 // We can skip it.
3348 this->skip_call_tls_get_addr_ = true;
3349 }
3350
3351 // Do a relocation in which we convert a TLS General-Dynamic to an
3352 // Initial-Exec.
3353
3354 inline void
3355 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3356 size_t relnum,
3357 const elfcpp::Rel<32, false>& rel,
3358 unsigned int,
3359 elfcpp::Elf_types<32>::Elf_Addr value,
3360 unsigned char* view,
3361 section_size_type view_size)
3362 {
3363 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3364 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3365 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3366 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3367
3368 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3369 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3370
3371 unsigned char op1 = view[-1];
3372 unsigned char op2 = view[-2];
3373
3374 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3375 op2 == 0x8d || op2 == 0x04);
3376 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3377
3378 int roff;
3379
3380 if (op2 == 0x04)
3381 {
3382 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3383 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3384 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3385 ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3386 roff = 5;
3387 }
3388 else
3389 {
3390 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
3391 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3392 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3393 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[9] == 0x90);
3394 roff = 6;
3395 }
3396
3397 memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3398 Relocate_functions<32, false>::rel32(view + roff, value);
3399
3400 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3401 // We can skip it.
3402 this->skip_call_tls_get_addr_ = true;
3403 }
3404
3405 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3406 // General-Dynamic to a Local-Exec.
3407
3408 inline void
3409 Target_i386::Relocate::tls_desc_gd_to_le(
3410 const Relocate_info<32, false>* relinfo,
3411 size_t relnum,
3412 Output_segment* tls_segment,
3413 const elfcpp::Rel<32, false>& rel,
3414 unsigned int r_type,
3415 elfcpp::Elf_types<32>::Elf_Addr value,
3416 unsigned char* view,
3417 section_size_type view_size)
3418 {
3419 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3420 {
3421 // leal foo@TLSDESC(%ebx), %eax
3422 // ==> leal foo@NTPOFF, %eax
3423 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3424 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3425 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3426 view[-2] == 0x8d && view[-1] == 0x83);
3427 view[-1] = 0x05;
3428 value -= tls_segment->memsz();
3429 Relocate_functions<32, false>::rel32(view, value);
3430 }
3431 else
3432 {
3433 // call *foo@TLSCALL(%eax)
3434 // ==> nop; nop
3435 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3436 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3437 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3438 view[0] == 0xff && view[1] == 0x10);
3439 view[0] = 0x66;
3440 view[1] = 0x90;
3441 }
3442 }
3443
3444 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3445 // General-Dynamic to an Initial-Exec.
3446
3447 inline void
3448 Target_i386::Relocate::tls_desc_gd_to_ie(
3449 const Relocate_info<32, false>* relinfo,
3450 size_t relnum,
3451 const elfcpp::Rel<32, false>& rel,
3452 unsigned int r_type,
3453 elfcpp::Elf_types<32>::Elf_Addr value,
3454 unsigned char* view,
3455 section_size_type view_size)
3456 {
3457 if (r_type == elfcpp::R_386_TLS_GOTDESC)
3458 {
3459 // leal foo@TLSDESC(%ebx), %eax
3460 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3461 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3462 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3463 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3464 view[-2] == 0x8d && view[-1] == 0x83);
3465 view[-2] = 0x8b;
3466 Relocate_functions<32, false>::rel32(view, value);
3467 }
3468 else
3469 {
3470 // call *foo@TLSCALL(%eax)
3471 // ==> nop; nop
3472 gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3473 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3474 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3475 view[0] == 0xff && view[1] == 0x10);
3476 view[0] = 0x66;
3477 view[1] = 0x90;
3478 }
3479 }
3480
3481 // Do a relocation in which we convert a TLS Local-Dynamic to a
3482 // Local-Exec.
3483
3484 inline void
3485 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3486 size_t relnum,
3487 Output_segment*,
3488 const elfcpp::Rel<32, false>& rel,
3489 unsigned int,
3490 elfcpp::Elf_types<32>::Elf_Addr,
3491 unsigned char* view,
3492 section_size_type view_size)
3493 {
3494 // leal foo(%reg), %eax; call ___tls_get_addr
3495 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3496
3497 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3498 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3499
3500 // FIXME: Does this test really always pass?
3501 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3502 view[-2] == 0x8d && view[-1] == 0x83);
3503
3504 tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3505
3506 memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3507
3508 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3509 // We can skip it.
3510 this->skip_call_tls_get_addr_ = true;
3511 }
3512
3513 // Do a relocation in which we convert a TLS Initial-Exec to a
3514 // Local-Exec.
3515
3516 inline void
3517 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3518 size_t relnum,
3519 Output_segment* tls_segment,
3520 const elfcpp::Rel<32, false>& rel,
3521 unsigned int r_type,
3522 elfcpp::Elf_types<32>::Elf_Addr value,
3523 unsigned char* view,
3524 section_size_type view_size)
3525 {
3526 // We have to actually change the instructions, which means that we
3527 // need to examine the opcodes to figure out which instruction we
3528 // are looking at.
3529 if (r_type == elfcpp::R_386_TLS_IE)
3530 {
3531 // movl %gs:XX,%eax ==> movl $YY,%eax
3532 // movl %gs:XX,%reg ==> movl $YY,%reg
3533 // addl %gs:XX,%reg ==> addl $YY,%reg
3534 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3535 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3536
3537 unsigned char op1 = view[-1];
3538 if (op1 == 0xa1)
3539 {
3540 // movl XX,%eax ==> movl $YY,%eax
3541 view[-1] = 0xb8;
3542 }
3543 else
3544 {
3545 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3546
3547 unsigned char op2 = view[-2];
3548 if (op2 == 0x8b)
3549 {
3550 // movl XX,%reg ==> movl $YY,%reg
3551 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3552 (op1 & 0xc7) == 0x05);
3553 view[-2] = 0xc7;
3554 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3555 }
3556 else if (op2 == 0x03)
3557 {
3558 // addl XX,%reg ==> addl $YY,%reg
3559 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3560 (op1 & 0xc7) == 0x05);
3561 view[-2] = 0x81;
3562 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3563 }
3564 else
3565 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3566 }
3567 }
3568 else
3569 {
3570 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3571 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3572 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3573 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3574 tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3575
3576 unsigned char op1 = view[-1];
3577 unsigned char op2 = view[-2];
3578 tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3579 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3580 if (op2 == 0x8b)
3581 {
3582 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3583 view[-2] = 0xc7;
3584 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3585 }
3586 else if (op2 == 0x2b)
3587 {
3588 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3589 view[-2] = 0x81;
3590 view[-1] = 0xe8 | ((op1 >> 3) & 7);
3591 }
3592 else if (op2 == 0x03)
3593 {
3594 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3595 view[-2] = 0x81;
3596 view[-1] = 0xc0 | ((op1 >> 3) & 7);
3597 }
3598 else
3599 tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3600 }
3601
3602 value = tls_segment->memsz() - value;
3603 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3604 value = - value;
3605
3606 Relocate_functions<32, false>::rel32(view, value);
3607 }
3608
3609 // Relocate section data.
3610
3611 void
3612 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3613 unsigned int sh_type,
3614 const unsigned char* prelocs,
3615 size_t reloc_count,
3616 Output_section* output_section,
3617 bool needs_special_offset_handling,
3618 unsigned char* view,
3619 elfcpp::Elf_types<32>::Elf_Addr address,
3620 section_size_type view_size,
3621 const Reloc_symbol_changes* reloc_symbol_changes)
3622 {
3623 gold_assert(sh_type == elfcpp::SHT_REL);
3624
3625 gold::relocate_section<32, false, Target_i386, Relocate,
3626 gold::Default_comdat_behavior, Classify_reloc>(
3627 relinfo,
3628 this,
3629 prelocs,
3630 reloc_count,
3631 output_section,
3632 needs_special_offset_handling,
3633 view,
3634 address,
3635 view_size,
3636 reloc_symbol_changes);
3637 }
3638
3639 // Return the size of a relocation while scanning during a relocatable
3640 // link.
3641
3642 unsigned int
3643 Target_i386::Classify_reloc::get_size_for_reloc(
3644 unsigned int r_type,
3645 Relobj* object)
3646 {
3647 switch (r_type)
3648 {
3649 case elfcpp::R_386_NONE:
3650 case elfcpp::R_386_GNU_VTINHERIT:
3651 case elfcpp::R_386_GNU_VTENTRY:
3652 case elfcpp::R_386_TLS_GD: // Global-dynamic
3653 case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
3654 case elfcpp::R_386_TLS_DESC_CALL:
3655 case elfcpp::R_386_TLS_LDM: // Local-dynamic
3656 case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
3657 case elfcpp::R_386_TLS_IE: // Initial-exec
3658 case elfcpp::R_386_TLS_IE_32:
3659 case elfcpp::R_386_TLS_GOTIE:
3660 case elfcpp::R_386_TLS_LE: // Local-exec
3661 case elfcpp::R_386_TLS_LE_32:
3662 return 0;
3663
3664 case elfcpp::R_386_32:
3665 case elfcpp::R_386_PC32:
3666 case elfcpp::R_386_GOT32:
3667 case elfcpp::R_386_GOT32X:
3668 case elfcpp::R_386_PLT32:
3669 case elfcpp::R_386_GOTOFF:
3670 case elfcpp::R_386_GOTPC:
3671 return 4;
3672
3673 case elfcpp::R_386_16:
3674 case elfcpp::R_386_PC16:
3675 return 2;
3676
3677 case elfcpp::R_386_8:
3678 case elfcpp::R_386_PC8:
3679 return 1;
3680
3681 // These are relocations which should only be seen by the
3682 // dynamic linker, and should never be seen here.
3683 case elfcpp::R_386_COPY:
3684 case elfcpp::R_386_GLOB_DAT:
3685 case elfcpp::R_386_JUMP_SLOT:
3686 case elfcpp::R_386_RELATIVE:
3687 case elfcpp::R_386_IRELATIVE:
3688 case elfcpp::R_386_TLS_TPOFF:
3689 case elfcpp::R_386_TLS_DTPMOD32:
3690 case elfcpp::R_386_TLS_DTPOFF32:
3691 case elfcpp::R_386_TLS_TPOFF32:
3692 case elfcpp::R_386_TLS_DESC:
3693 object->error(_("unexpected reloc %u in object file"), r_type);
3694 return 0;
3695
3696 case elfcpp::R_386_32PLT:
3697 case elfcpp::R_386_TLS_GD_32:
3698 case elfcpp::R_386_TLS_GD_PUSH:
3699 case elfcpp::R_386_TLS_GD_CALL:
3700 case elfcpp::R_386_TLS_GD_POP:
3701 case elfcpp::R_386_TLS_LDM_32:
3702 case elfcpp::R_386_TLS_LDM_PUSH:
3703 case elfcpp::R_386_TLS_LDM_CALL:
3704 case elfcpp::R_386_TLS_LDM_POP:
3705 case elfcpp::R_386_USED_BY_INTEL_200:
3706 default:
3707 object->error(_("unsupported reloc %u in object file"), r_type);
3708 return 0;
3709 }
3710 }
3711
3712 // Scan the relocs during a relocatable link.
3713
3714 void
3715 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3716 Layout* layout,
3717 Sized_relobj_file<32, false>* object,
3718 unsigned int data_shndx,
3719 unsigned int sh_type,
3720 const unsigned char* prelocs,
3721 size_t reloc_count,
3722 Output_section* output_section,
3723 bool needs_special_offset_handling,
3724 size_t local_symbol_count,
3725 const unsigned char* plocal_symbols,
3726 Relocatable_relocs* rr)
3727 {
3728 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
3729 Scan_relocatable_relocs;
3730
3731 gold_assert(sh_type == elfcpp::SHT_REL);
3732
3733 gold::scan_relocatable_relocs<32, false, Scan_relocatable_relocs>(
3734 symtab,
3735 layout,
3736 object,
3737 data_shndx,
3738 prelocs,
3739 reloc_count,
3740 output_section,
3741 needs_special_offset_handling,
3742 local_symbol_count,
3743 plocal_symbols,
3744 rr);
3745 }
3746
3747 // Scan the relocs for --emit-relocs.
3748
3749 void
3750 Target_i386::emit_relocs_scan(Symbol_table* symtab,
3751 Layout* layout,
3752 Sized_relobj_file<32, false>* object,
3753 unsigned int data_shndx,
3754 unsigned int sh_type,
3755 const unsigned char* prelocs,
3756 size_t reloc_count,
3757 Output_section* output_section,
3758 bool needs_special_offset_handling,
3759 size_t local_symbol_count,
3760 const unsigned char* plocal_syms,
3761 Relocatable_relocs* rr)
3762 {
3763 typedef gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
3764 Classify_reloc;
3765 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
3766 Emit_relocs_strategy;
3767
3768 gold_assert(sh_type == elfcpp::SHT_REL);
3769
3770 gold::scan_relocatable_relocs<32, false, Emit_relocs_strategy>(
3771 symtab,
3772 layout,
3773 object,
3774 data_shndx,
3775 prelocs,
3776 reloc_count,
3777 output_section,
3778 needs_special_offset_handling,
3779 local_symbol_count,
3780 plocal_syms,
3781 rr);
3782 }
3783
3784 // Emit relocations for a section.
3785
3786 void
3787 Target_i386::relocate_relocs(
3788 const Relocate_info<32, false>* relinfo,
3789 unsigned int sh_type,
3790 const unsigned char* prelocs,
3791 size_t reloc_count,
3792 Output_section* output_section,
3793 elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
3794 unsigned char* view,
3795 elfcpp::Elf_types<32>::Elf_Addr view_address,
3796 section_size_type view_size,
3797 unsigned char* reloc_view,
3798 section_size_type reloc_view_size)
3799 {
3800 gold_assert(sh_type == elfcpp::SHT_REL);
3801
3802 gold::relocate_relocs<32, false, Classify_reloc>(
3803 relinfo,
3804 prelocs,
3805 reloc_count,
3806 output_section,
3807 offset_in_output_section,
3808 view,
3809 view_address,
3810 view_size,
3811 reloc_view,
3812 reloc_view_size);
3813 }
3814
3815 // Return the value to use for a dynamic which requires special
3816 // treatment. This is how we support equality comparisons of function
3817 // pointers across shared library boundaries, as described in the
3818 // processor specific ABI supplement.
3819
3820 uint64_t
3821 Target_i386::do_dynsym_value(const Symbol* gsym) const
3822 {
3823 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3824 return this->plt_address_for_global(gsym);
3825 }
3826
3827 // Return a string used to fill a code section with nops to take up
3828 // the specified length.
3829
3830 std::string
3831 Target_i386::do_code_fill(section_size_type length) const
3832 {
3833 if (length >= 16)
3834 {
3835 // Build a jmp instruction to skip over the bytes.
3836 unsigned char jmp[5];
3837 jmp[0] = 0xe9;
3838 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3839 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3840 + std::string(length - 5, static_cast<char>(0x90)));
3841 }
3842
3843 // Nop sequences of various lengths.
3844 const char nop1[1] = { '\x90' }; // nop
3845 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
3846 const char nop3[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3847 const char nop4[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3848 '\x00'};
3849 const char nop5[5] = { '\x90', '\x8d', '\x74', // nop
3850 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3851 const char nop6[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3852 '\x00', '\x00', '\x00' };
3853 const char nop7[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3854 '\x00', '\x00', '\x00',
3855 '\x00' };
3856 const char nop8[8] = { '\x90', '\x8d', '\xb4', // nop
3857 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3858 '\x00', '\x00' };
3859 const char nop9[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3860 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3861 '\x00', '\x00', '\x00' };
3862 const char nop10[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3863 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3864 '\x00', '\x00', '\x00',
3865 '\x00' };
3866 const char nop11[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3867 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3868 '\x27', '\x00', '\x00',
3869 '\x00', '\x00' };
3870 const char nop12[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3871 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3872 '\x8d', '\xbf', '\x00',
3873 '\x00', '\x00', '\x00' };
3874 const char nop13[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3875 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3876 '\x8d', '\xbc', '\x27',
3877 '\x00', '\x00', '\x00',
3878 '\x00' };
3879 const char nop14[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3880 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3881 '\x00', '\x8d', '\xbc',
3882 '\x27', '\x00', '\x00',
3883 '\x00', '\x00' };
3884 const char nop15[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3885 '\x90', '\x90', '\x90', // nop,nop,nop,...
3886 '\x90', '\x90', '\x90',
3887 '\x90', '\x90', '\x90',
3888 '\x90', '\x90', '\x90' };
3889
3890 const char* nops[16] = {
3891 NULL,
3892 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3893 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3894 };
3895
3896 return std::string(nops[length], length);
3897 }
3898
3899 // Return the value to use for the base of a DW_EH_PE_datarel offset
3900 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3901 // assembler can not write out the difference between two labels in
3902 // different sections, so instead of using a pc-relative value they
3903 // use an offset from the GOT.
3904
3905 uint64_t
3906 Target_i386::do_ehframe_datarel_base() const
3907 {
3908 gold_assert(this->global_offset_table_ != NULL);
3909 Symbol* sym = this->global_offset_table_;
3910 Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3911 return ssym->value();
3912 }
3913
3914 // Return whether SYM should be treated as a call to a non-split
3915 // function. We don't want that to be true of a call to a
3916 // get_pc_thunk function.
3917
3918 bool
3919 Target_i386::do_is_call_to_non_split(const Symbol* sym,
3920 const unsigned char*) const
3921 {
3922 return (sym->type() == elfcpp::STT_FUNC
3923 && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3924 }
3925
3926 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3927 // compiled with -fsplit-stack. The function calls non-split-stack
3928 // code. We have to change the function so that it always ensures
3929 // that it has enough stack space to run some random function.
3930
3931 void
3932 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3933 section_offset_type fnoffset,
3934 section_size_type fnsize,
3935 const unsigned char*,
3936 size_t,
3937 unsigned char* view,
3938 section_size_type view_size,
3939 std::string* from,
3940 std::string* to) const
3941 {
3942 // The function starts with a comparison of the stack pointer and a
3943 // field in the TCB. This is followed by a jump.
3944
3945 // cmp %gs:NN,%esp
3946 if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3947 && fnsize > 7)
3948 {
3949 // We will call __morestack if the carry flag is set after this
3950 // comparison. We turn the comparison into an stc instruction
3951 // and some nops.
3952 view[fnoffset] = '\xf9';
3953 this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3954 }
3955 // lea NN(%esp),%ecx
3956 // lea NN(%esp),%edx
3957 else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3958 || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3959 && fnsize > 7)
3960 {
3961 // This is loading an offset from the stack pointer for a
3962 // comparison. The offset is negative, so we decrease the
3963 // offset by the amount of space we need for the stack. This
3964 // means we will avoid calling __morestack if there happens to
3965 // be plenty of space on the stack already.
3966 unsigned char* pval = view + fnoffset + 3;
3967 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3968 val -= parameters->options().split_stack_adjust_size();
3969 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3970 }
3971 else
3972 {
3973 if (!object->has_no_split_stack())
3974 object->error(_("failed to match split-stack sequence at "
3975 "section %u offset %0zx"),
3976 shndx, static_cast<size_t>(fnoffset));
3977 return;
3978 }
3979
3980 // We have to change the function so that it calls
3981 // __morestack_non_split instead of __morestack. The former will
3982 // allocate additional stack space.
3983 *from = "__morestack";
3984 *to = "__morestack_non_split";
3985 }
3986
3987 // The selector for i386 object files. Note this is never instantiated
3988 // directly. It's only used in Target_selector_i386_nacl, below.
3989
3990 class Target_selector_i386 : public Target_selector_freebsd
3991 {
3992 public:
3993 Target_selector_i386()
3994 : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3995 "elf32-i386", "elf32-i386-freebsd",
3996 "elf_i386")
3997 { }
3998
3999 Target*
4000 do_instantiate_target()
4001 { return new Target_i386(); }
4002 };
4003
4004 // NaCl variant. It uses different PLT contents.
4005
4006 class Output_data_plt_i386_nacl : public Output_data_plt_i386
4007 {
4008 public:
4009 Output_data_plt_i386_nacl(Layout* layout,
4010 Output_data_got_plt_i386* got_plt,
4011 Output_data_space* got_irelative)
4012 : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
4013 { }
4014
4015 protected:
4016 virtual unsigned int
4017 do_get_plt_entry_size() const
4018 { return plt_entry_size; }
4019
4020 virtual void
4021 do_add_eh_frame(Layout* layout)
4022 {
4023 layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
4024 plt_eh_frame_fde, plt_eh_frame_fde_size);
4025 }
4026
4027 // The size of an entry in the PLT.
4028 static const int plt_entry_size = 64;
4029
4030 // The .eh_frame unwind information for the PLT.
4031 static const int plt_eh_frame_fde_size = 32;
4032 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4033 };
4034
4035 class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
4036 {
4037 public:
4038 Output_data_plt_i386_nacl_exec(Layout* layout,
4039 Output_data_got_plt_i386* got_plt,
4040 Output_data_space* got_irelative)
4041 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4042 { }
4043
4044 protected:
4045 virtual void
4046 do_fill_first_plt_entry(unsigned char* pov,
4047 elfcpp::Elf_types<32>::Elf_Addr got_address);
4048
4049 virtual unsigned int
4050 do_fill_plt_entry(unsigned char* pov,
4051 elfcpp::Elf_types<32>::Elf_Addr got_address,
4052 unsigned int got_offset,
4053 unsigned int plt_offset,
4054 unsigned int plt_rel_offset);
4055
4056 private:
4057 // The first entry in the PLT for an executable.
4058 static const unsigned char first_plt_entry[plt_entry_size];
4059
4060 // Other entries in the PLT for an executable.
4061 static const unsigned char plt_entry[plt_entry_size];
4062 };
4063
4064 class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
4065 {
4066 public:
4067 Output_data_plt_i386_nacl_dyn(Layout* layout,
4068 Output_data_got_plt_i386* got_plt,
4069 Output_data_space* got_irelative)
4070 : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
4071 { }
4072
4073 protected:
4074 virtual void
4075 do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);
4076
4077 virtual unsigned int
4078 do_fill_plt_entry(unsigned char* pov,
4079 elfcpp::Elf_types<32>::Elf_Addr,
4080 unsigned int got_offset,
4081 unsigned int plt_offset,
4082 unsigned int plt_rel_offset);
4083
4084 private:
4085 // The first entry in the PLT for a shared object.
4086 static const unsigned char first_plt_entry[plt_entry_size];
4087
4088 // Other entries in the PLT for a shared object.
4089 static const unsigned char plt_entry[plt_entry_size];
4090 };
4091
4092 class Target_i386_nacl : public Target_i386
4093 {
4094 public:
4095 Target_i386_nacl()
4096 : Target_i386(&i386_nacl_info)
4097 { }
4098
4099 protected:
4100 virtual Output_data_plt_i386*
4101 do_make_data_plt(Layout* layout,
4102 Output_data_got_plt_i386* got_plt,
4103 Output_data_space* got_irelative,
4104 bool dyn)
4105 {
4106 if (dyn)
4107 return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
4108 else
4109 return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
4110 }
4111
4112 virtual std::string
4113 do_code_fill(section_size_type length) const;
4114
4115 private:
4116 static const Target::Target_info i386_nacl_info;
4117 };
4118
4119 const Target::Target_info Target_i386_nacl::i386_nacl_info =
4120 {
4121 32, // size
4122 false, // is_big_endian
4123 elfcpp::EM_386, // machine_code
4124 false, // has_make_symbol
4125 false, // has_resolve
4126 true, // has_code_fill
4127 true, // is_default_stack_executable
4128 true, // can_icf_inline_merge_sections
4129 '\0', // wrap_char
4130 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4131 0x20000, // default_text_segment_address
4132 0x10000, // abi_pagesize (overridable by -z max-page-size)
4133 0x10000, // common_pagesize (overridable by -z common-page-size)
4134 true, // isolate_execinstr
4135 0x10000000, // rosegment_gap
4136 elfcpp::SHN_UNDEF, // small_common_shndx
4137 elfcpp::SHN_UNDEF, // large_common_shndx
4138 0, // small_common_section_flags
4139 0, // large_common_section_flags
4140 NULL, // attributes_section
4141 NULL, // attributes_vendor
4142 "_start", // entry_symbol_name
4143 32, // hash_entry_size
4144 };
4145
4146 #define NACLMASK 0xe0 // 32-byte alignment mask
4147
4148 const unsigned char
4149 Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
4150 {
4151 0xff, 0x35, // pushl contents of memory address
4152 0, 0, 0, 0, // replaced with address of .got + 4
4153 0x8b, 0x0d, // movl contents of address, %ecx
4154 0, 0, 0, 0, // replaced with address of .got + 8
4155 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4156 0xff, 0xe1, // jmp *%ecx
4157 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4158 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4159 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4160 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4161 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4162 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4163 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4164 0x90, 0x90, 0x90, 0x90, 0x90
4165 };
4166
4167 void
4168 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4169 unsigned char* pov,
4170 elfcpp::Elf_types<32>::Elf_Addr got_address)
4171 {
4172 memcpy(pov, first_plt_entry, plt_entry_size);
4173 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
4174 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
4175 }
4176
4177 // The first entry in the PLT for a shared object.
4178
4179 const unsigned char
4180 Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
4181 {
4182 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4183 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4184 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4185 0xff, 0xe1, // jmp *%ecx
4186 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4187 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4188 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4189 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4190 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4191 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4192 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4193 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4194 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4195 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4196 };
4197
4198 void
4199 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4200 unsigned char* pov,
4201 elfcpp::Elf_types<32>::Elf_Addr)
4202 {
4203 memcpy(pov, first_plt_entry, plt_entry_size);
4204 }
4205
4206 // Subsequent entries in the PLT for an executable.
4207
4208 const unsigned char
4209 Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
4210 {
4211 0x8b, 0x0d, // movl contents of address, %ecx */
4212 0, 0, 0, 0, // replaced with address of symbol in .got
4213 0x83, 0xe1, NACLMASK, // andl $NACLMASK, %ecx
4214 0xff, 0xe1, // jmp *%ecx
4215
4216 // Pad to the next 32-byte boundary with nop instructions.
4217 0x90,
4218 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4219 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4220
4221 // Lazy GOT entries point here (32-byte aligned).
4222 0x68, // pushl immediate
4223 0, 0, 0, 0, // replaced with offset into relocation table
4224 0xe9, // jmp relative
4225 0, 0, 0, 0, // replaced with offset to start of .plt
4226
4227 // Pad to the next 32-byte boundary with nop instructions.
4228 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4229 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4230 0x90, 0x90
4231 };
4232
4233 unsigned int
4234 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4235 unsigned char* pov,
4236 elfcpp::Elf_types<32>::Elf_Addr got_address,
4237 unsigned int got_offset,
4238 unsigned int plt_offset,
4239 unsigned int plt_rel_offset)
4240 {
4241 memcpy(pov, plt_entry, plt_entry_size);
4242 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4243 got_address + got_offset);
4244 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4245 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4246 return 32;
4247 }
4248
4249 // Subsequent entries in the PLT for a shared object.
4250
4251 const unsigned char
4252 Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
4253 {
4254 0x8b, 0x8b, // movl offset(%ebx), %ecx
4255 0, 0, 0, 0, // replaced with offset of symbol in .got
4256 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4257 0xff, 0xe1, // jmp *%ecx
4258
4259 // Pad to the next 32-byte boundary with nop instructions.
4260 0x90,
4261 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4262 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4263
4264 // Lazy GOT entries point here (32-byte aligned).
4265 0x68, // pushl immediate
4266 0, 0, 0, 0, // replaced with offset into relocation table.
4267 0xe9, // jmp relative
4268 0, 0, 0, 0, // replaced with offset to start of .plt.
4269
4270 // Pad to the next 32-byte boundary with nop instructions.
4271 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4272 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4273 0x90, 0x90
4274 };
4275
4276 unsigned int
4277 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4278 unsigned char* pov,
4279 elfcpp::Elf_types<32>::Elf_Addr,
4280 unsigned int got_offset,
4281 unsigned int plt_offset,
4282 unsigned int plt_rel_offset)
4283 {
4284 memcpy(pov, plt_entry, plt_entry_size);
4285 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
4286 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
4287 elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
4288 return 32;
4289 }
4290
4291 const unsigned char
4292 Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4293 {
4294 0, 0, 0, 0, // Replaced with offset to .plt.
4295 0, 0, 0, 0, // Replaced with size of .plt.
4296 0, // Augmentation size.
4297 elfcpp::DW_CFA_def_cfa_offset, 8, // DW_CFA_def_cfa_offset: 8.
4298 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
4299 elfcpp::DW_CFA_def_cfa_offset, 12, // DW_CFA_def_cfa_offset: 12.
4300 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
4301 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
4302 13, // Block length.
4303 elfcpp::DW_OP_breg4, 4, // Push %esp + 4.
4304 elfcpp::DW_OP_breg8, 0, // Push %eip.
4305 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
4306 elfcpp::DW_OP_and, // & (%eip & 0x3f).
4307 elfcpp::DW_OP_const1u, 37, // Push 0x25.
4308 elfcpp::DW_OP_ge, // >= ((%eip & 0x3f) >= 0x25)
4309 elfcpp::DW_OP_lit2, // Push 2.
4310 elfcpp::DW_OP_shl, // << (((%eip & 0x3f) >= 0x25) << 2)
4311 elfcpp::DW_OP_plus, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4312 elfcpp::DW_CFA_nop, // Align to 32 bytes.
4313 elfcpp::DW_CFA_nop
4314 };
4315
4316 // Return a string used to fill a code section with nops.
4317 // For NaCl, long NOPs are only valid if they do not cross
4318 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4319 std::string
4320 Target_i386_nacl::do_code_fill(section_size_type length) const
4321 {
4322 return std::string(length, static_cast<char>(0x90));
4323 }
4324
4325 // The selector for i386-nacl object files.
4326
4327 class Target_selector_i386_nacl
4328 : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
4329 {
4330 public:
4331 Target_selector_i386_nacl()
4332 : Target_selector_nacl<Target_selector_i386,
4333 Target_i386_nacl>("x86-32",
4334 "elf32-i386-nacl",
4335 "elf_i386_nacl")
4336 { }
4337 };
4338
4339 Target_selector_i386_nacl target_selector_i386;
4340
4341 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4342
4343 class Target_iamcu : public Target_i386
4344 {
4345 public:
4346 Target_iamcu()
4347 : Target_i386(&iamcu_info)
4348 { }
4349
4350 private:
4351 // Information about this specific target which we pass to the
4352 // general Target structure.
4353 static const Target::Target_info iamcu_info;
4354 };
4355
4356 const Target::Target_info Target_iamcu::iamcu_info =
4357 {
4358 32, // size
4359 false, // is_big_endian
4360 elfcpp::EM_IAMCU, // machine_code
4361 false, // has_make_symbol
4362 false, // has_resolve
4363 true, // has_code_fill
4364 true, // is_default_stack_executable
4365 true, // can_icf_inline_merge_sections
4366 '\0', // wrap_char
4367 "/usr/lib/libc.so.1", // dynamic_linker
4368 0x08048000, // default_text_segment_address
4369 0x1000, // abi_pagesize (overridable by -z max-page-size)
4370 0x1000, // common_pagesize (overridable by -z common-page-size)
4371 false, // isolate_execinstr
4372 0, // rosegment_gap
4373 elfcpp::SHN_UNDEF, // small_common_shndx
4374 elfcpp::SHN_UNDEF, // large_common_shndx
4375 0, // small_common_section_flags
4376 0, // large_common_section_flags
4377 NULL, // attributes_section
4378 NULL, // attributes_vendor
4379 "_start", // entry_symbol_name
4380 32, // hash_entry_size
4381 };
4382
4383 class Target_selector_iamcu : public Target_selector
4384 {
4385 public:
4386 Target_selector_iamcu()
4387 : Target_selector(elfcpp::EM_IAMCU, 32, false, "elf32-iamcu",
4388 "elf_iamcu")
4389 { }
4390
4391 Target*
4392 do_instantiate_target()
4393 { return new Target_iamcu(); }
4394 };
4395
4396 Target_selector_iamcu target_selector_iamcu;
4397
4398 } // End anonymous namespace.
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