x86: Update UNDEFINED_WEAK_RESOLVED_TO_ZERO
[deliverable/binutils-gdb.git] / bfd / elfxx-x86.c
1 /* x86 specific support for ELF
2 Copyright (C) 2017 Free Software Foundation, Inc.
3
4 This file is part of BFD, the Binary File Descriptor library.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 #include "elfxx-x86.h"
22 #include "elf-vxworks.h"
23 #include "objalloc.h"
24 #include "elf/i386.h"
25 #include "elf/x86-64.h"
26
27 /* The name of the dynamic interpreter. This is put in the .interp
28 section. */
29
30 #define ELF32_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1"
31 #define ELF64_DYNAMIC_INTERPRETER "/lib/ld64.so.1"
32 #define ELFX32_DYNAMIC_INTERPRETER "/lib/ldx32.so.1"
33
34 bfd_boolean
35 _bfd_x86_elf_mkobject (bfd *abfd)
36 {
37 return bfd_elf_allocate_object (abfd,
38 sizeof (struct elf_x86_obj_tdata),
39 get_elf_backend_data (abfd)->target_id);
40 }
41
42 /* _TLS_MODULE_BASE_ needs to be treated especially when linking
43 executables. Rather than setting it to the beginning of the TLS
44 section, we have to set it to the end. This function may be called
45 multiple times, it is idempotent. */
46
47 void
48 _bfd_x86_elf_set_tls_module_base (struct bfd_link_info *info)
49 {
50 struct elf_x86_link_hash_table *htab;
51 struct bfd_link_hash_entry *base;
52 const struct elf_backend_data *bed;
53
54 if (!bfd_link_executable (info))
55 return;
56
57 bed = get_elf_backend_data (info->output_bfd);
58 htab = elf_x86_hash_table (info, bed->target_id);
59 if (htab == NULL)
60 return;
61
62 base = htab->tls_module_base;
63 if (base == NULL)
64 return;
65
66 base->u.def.value = htab->elf.tls_size;
67 }
68
69 /* Return the base VMA address which should be subtracted from real addresses
70 when resolving @dtpoff relocation.
71 This is PT_TLS segment p_vaddr. */
72
73 bfd_vma
74 _bfd_x86_elf_dtpoff_base (struct bfd_link_info *info)
75 {
76 /* If tls_sec is NULL, we should have signalled an error already. */
77 if (elf_hash_table (info)->tls_sec == NULL)
78 return 0;
79 return elf_hash_table (info)->tls_sec->vma;
80 }
81
82 /* Allocate space in .plt, .got and associated reloc sections for
83 dynamic relocs. */
84
85 static bfd_boolean
86 elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h,
87 void *inf)
88 {
89 struct bfd_link_info *info;
90 struct elf_x86_link_hash_table *htab;
91 struct elf_x86_link_hash_entry *eh;
92 struct elf_dyn_relocs *p;
93 unsigned int plt_entry_size;
94 bfd_boolean resolved_to_zero;
95 const struct elf_backend_data *bed;
96
97 if (h->root.type == bfd_link_hash_indirect)
98 return TRUE;
99
100 eh = (struct elf_x86_link_hash_entry *) h;
101
102 info = (struct bfd_link_info *) inf;
103 bed = get_elf_backend_data (info->output_bfd);
104 htab = elf_x86_hash_table (info, bed->target_id);
105 if (htab == NULL)
106 return FALSE;
107
108 plt_entry_size = htab->plt.plt_entry_size;
109
110 resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
111
112 /* Clear the reference count of function pointer relocations if
113 symbol isn't a normal function. */
114 if (h->type != STT_FUNC)
115 eh->func_pointer_refcount = 0;
116
117 /* We can't use the GOT PLT if pointer equality is needed since
118 finish_dynamic_symbol won't clear symbol value and the dynamic
119 linker won't update the GOT slot. We will get into an infinite
120 loop at run-time. */
121 if (htab->plt_got != NULL
122 && h->type != STT_GNU_IFUNC
123 && !h->pointer_equality_needed
124 && h->plt.refcount > 0
125 && h->got.refcount > 0)
126 {
127 /* Don't use the regular PLT if there are both GOT and GOTPLT
128 reloctions. */
129 h->plt.offset = (bfd_vma) -1;
130
131 /* Use the GOT PLT. */
132 eh->plt_got.refcount = 1;
133 }
134
135 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
136 here if it is defined and referenced in a non-shared object. */
137 if (h->type == STT_GNU_IFUNC
138 && h->def_regular)
139 {
140 if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs,
141 &htab->readonly_dynrelocs_against_ifunc,
142 plt_entry_size,
143 (htab->plt.has_plt0
144 * plt_entry_size),
145 htab->got_entry_size,
146 TRUE))
147 {
148 asection *s = htab->plt_second;
149 if (h->plt.offset != (bfd_vma) -1 && s != NULL)
150 {
151 /* Use the second PLT section if it is created. */
152 eh->plt_second.offset = s->size;
153
154 /* Make room for this entry in the second PLT section. */
155 s->size += htab->non_lazy_plt->plt_entry_size;
156 }
157
158 return TRUE;
159 }
160 else
161 return FALSE;
162 }
163 /* Don't create the PLT entry if there are only function pointer
164 relocations which can be resolved at run-time. */
165 else if (htab->elf.dynamic_sections_created
166 && (h->plt.refcount > eh->func_pointer_refcount
167 || eh->plt_got.refcount > 0))
168 {
169 bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
170
171 /* Clear the reference count of function pointer relocations
172 if PLT is used. */
173 eh->func_pointer_refcount = 0;
174
175 /* Make sure this symbol is output as a dynamic symbol.
176 Undefined weak syms won't yet be marked as dynamic. */
177 if (h->dynindx == -1
178 && !h->forced_local
179 && !resolved_to_zero
180 && h->root.type == bfd_link_hash_undefweak)
181 {
182 if (! bfd_elf_link_record_dynamic_symbol (info, h))
183 return FALSE;
184 }
185
186 if (bfd_link_pic (info)
187 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
188 {
189 asection *s = htab->elf.splt;
190 asection *second_s = htab->plt_second;
191 asection *got_s = htab->plt_got;
192
193 /* If this is the first .plt entry, make room for the special
194 first entry. The .plt section is used by prelink to undo
195 prelinking for dynamic relocations. */
196 if (s->size == 0)
197 s->size = htab->plt.has_plt0 * plt_entry_size;
198
199 if (use_plt_got)
200 eh->plt_got.offset = got_s->size;
201 else
202 {
203 h->plt.offset = s->size;
204 if (second_s)
205 eh->plt_second.offset = second_s->size;
206 }
207
208 /* If this symbol is not defined in a regular file, and we are
209 not generating a shared library, then set the symbol to this
210 location in the .plt. This is required to make function
211 pointers compare as equal between the normal executable and
212 the shared library. */
213 if (! bfd_link_pic (info)
214 && !h->def_regular)
215 {
216 if (use_plt_got)
217 {
218 /* We need to make a call to the entry of the GOT PLT
219 instead of regular PLT entry. */
220 h->root.u.def.section = got_s;
221 h->root.u.def.value = eh->plt_got.offset;
222 }
223 else
224 {
225 if (second_s)
226 {
227 /* We need to make a call to the entry of the
228 second PLT instead of regular PLT entry. */
229 h->root.u.def.section = second_s;
230 h->root.u.def.value = eh->plt_second.offset;
231 }
232 else
233 {
234 h->root.u.def.section = s;
235 h->root.u.def.value = h->plt.offset;
236 }
237 }
238 }
239
240 /* Make room for this entry. */
241 if (use_plt_got)
242 got_s->size += htab->non_lazy_plt->plt_entry_size;
243 else
244 {
245 s->size += plt_entry_size;
246 if (second_s)
247 second_s->size += htab->non_lazy_plt->plt_entry_size;
248
249 /* We also need to make an entry in the .got.plt section,
250 which will be placed in the .got section by the linker
251 script. */
252 htab->elf.sgotplt->size += htab->got_entry_size;
253
254 /* There should be no PLT relocation against resolved
255 undefined weak symbol in executable. */
256 if (!resolved_to_zero)
257 {
258 /* We also need to make an entry in the .rel.plt
259 section. */
260 htab->elf.srelplt->size += htab->sizeof_reloc;
261 htab->elf.srelplt->reloc_count++;
262 }
263 }
264
265 if (htab->is_vxworks && !bfd_link_pic (info))
266 {
267 /* VxWorks has a second set of relocations for each PLT entry
268 in executables. They go in a separate relocation section,
269 which is processed by the kernel loader. */
270
271 /* There are two relocations for the initial PLT entry: an
272 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
273 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
274
275 asection *srelplt2 = htab->srelplt2;
276 if (h->plt.offset == plt_entry_size)
277 srelplt2->size += (htab->sizeof_reloc * 2);
278
279 /* There are two extra relocations for each subsequent PLT entry:
280 an R_386_32 relocation for the GOT entry, and an R_386_32
281 relocation for the PLT entry. */
282
283 srelplt2->size += (htab->sizeof_reloc * 2);
284 }
285 }
286 else
287 {
288 eh->plt_got.offset = (bfd_vma) -1;
289 h->plt.offset = (bfd_vma) -1;
290 h->needs_plt = 0;
291 }
292 }
293 else
294 {
295 eh->plt_got.offset = (bfd_vma) -1;
296 h->plt.offset = (bfd_vma) -1;
297 h->needs_plt = 0;
298 }
299
300 eh->tlsdesc_got = (bfd_vma) -1;
301
302 /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the
303 binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For
304 x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary,
305 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
306 if (h->got.refcount > 0
307 && bfd_link_executable (info)
308 && h->dynindx == -1
309 && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
310 h->got.offset = (bfd_vma) -1;
311 else if (h->got.refcount > 0)
312 {
313 asection *s;
314 bfd_boolean dyn;
315 int tls_type = elf_x86_hash_entry (h)->tls_type;
316
317 /* Make sure this symbol is output as a dynamic symbol.
318 Undefined weak syms won't yet be marked as dynamic. */
319 if (h->dynindx == -1
320 && !h->forced_local
321 && !resolved_to_zero
322 && h->root.type == bfd_link_hash_undefweak)
323 {
324 if (! bfd_elf_link_record_dynamic_symbol (info, h))
325 return FALSE;
326 }
327
328 s = htab->elf.sgot;
329 if (GOT_TLS_GDESC_P (tls_type))
330 {
331 eh->tlsdesc_got = htab->elf.sgotplt->size
332 - elf_x86_compute_jump_table_size (htab);
333 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
334 h->got.offset = (bfd_vma) -2;
335 }
336 if (! GOT_TLS_GDESC_P (tls_type)
337 || GOT_TLS_GD_P (tls_type))
338 {
339 h->got.offset = s->size;
340 s->size += htab->got_entry_size;
341 /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT
342 slots. */
343 if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
344 s->size += htab->got_entry_size;
345 }
346 dyn = htab->elf.dynamic_sections_created;
347 /* R_386_TLS_IE_32 needs one dynamic relocation,
348 R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
349 (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
350 need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local
351 symbol and two if global. No dynamic relocation against
352 resolved undefined weak symbol in executable. */
353 if (tls_type == GOT_TLS_IE_BOTH)
354 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
355 else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
356 || (tls_type & GOT_TLS_IE))
357 htab->elf.srelgot->size += htab->sizeof_reloc;
358 else if (GOT_TLS_GD_P (tls_type))
359 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
360 else if (! GOT_TLS_GDESC_P (tls_type)
361 && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
362 && !resolved_to_zero)
363 || h->root.type != bfd_link_hash_undefweak)
364 && (bfd_link_pic (info)
365 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
366 htab->elf.srelgot->size += htab->sizeof_reloc;
367 if (GOT_TLS_GDESC_P (tls_type))
368 {
369 htab->elf.srelplt->size += htab->sizeof_reloc;
370 if (bed->target_id == X86_64_ELF_DATA)
371 htab->tlsdesc_plt = (bfd_vma) -1;
372 }
373 }
374 else
375 h->got.offset = (bfd_vma) -1;
376
377 if (eh->dyn_relocs == NULL)
378 return TRUE;
379
380 /* In the shared -Bsymbolic case, discard space allocated for
381 dynamic pc-relative relocs against symbols which turn out to be
382 defined in regular objects. For the normal shared case, discard
383 space for pc-relative relocs that have become local due to symbol
384 visibility changes. */
385
386 if (bfd_link_pic (info))
387 {
388 /* Relocs that use pc_count are those that appear on a call
389 insn, or certain REL relocs that can generated via assembly.
390 We want calls to protected symbols to resolve directly to the
391 function rather than going via the plt. If people want
392 function pointer comparisons to work as expected then they
393 should avoid writing weird assembly. */
394 if (SYMBOL_CALLS_LOCAL (info, h))
395 {
396 struct elf_dyn_relocs **pp;
397
398 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
399 {
400 p->count -= p->pc_count;
401 p->pc_count = 0;
402 if (p->count == 0)
403 *pp = p->next;
404 else
405 pp = &p->next;
406 }
407 }
408
409 if (htab->is_vxworks)
410 {
411 struct elf_dyn_relocs **pp;
412 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
413 {
414 if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
415 *pp = p->next;
416 else
417 pp = &p->next;
418 }
419 }
420
421 /* Also discard relocs on undefined weak syms with non-default
422 visibility or in PIE. */
423 if (eh->dyn_relocs != NULL)
424 {
425 if (h->root.type == bfd_link_hash_undefweak)
426 {
427 /* Undefined weak symbol is never bound locally in shared
428 library. */
429 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
430 || resolved_to_zero)
431 {
432 if (bed->target_id == I386_ELF_DATA
433 && h->non_got_ref)
434 {
435 /* Keep dynamic non-GOT/non-PLT relocation so
436 that we can branch to 0 without PLT. */
437 struct elf_dyn_relocs **pp;
438
439 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
440 if (p->pc_count == 0)
441 *pp = p->next;
442 else
443 {
444 /* Remove non-R_386_PC32 relocation. */
445 p->count = p->pc_count;
446 pp = &p->next;
447 }
448
449 /* Make sure undefined weak symbols are output
450 as dynamic symbols in PIEs for dynamic non-GOT
451 non-PLT reloations. */
452 if (eh->dyn_relocs != NULL
453 && !bfd_elf_link_record_dynamic_symbol (info, h))
454 return FALSE;
455 }
456 else
457 eh->dyn_relocs = NULL;
458 }
459 else if (h->dynindx == -1
460 && !h->forced_local
461 && !bfd_elf_link_record_dynamic_symbol (info, h))
462 return FALSE;
463 }
464 else if (bfd_link_executable (info)
465 && (h->needs_copy || eh->needs_copy)
466 && h->def_dynamic
467 && !h->def_regular)
468 {
469 /* NB: needs_copy is set only for x86-64. For PIE,
470 discard space for pc-relative relocs against symbols
471 which turn out to need copy relocs. */
472 struct elf_dyn_relocs **pp;
473
474 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
475 {
476 if (p->pc_count != 0)
477 *pp = p->next;
478 else
479 pp = &p->next;
480 }
481 }
482 }
483 }
484 else if (ELIMINATE_COPY_RELOCS)
485 {
486 /* For the non-shared case, discard space for relocs against
487 symbols which turn out to need copy relocs or are not
488 dynamic. Keep dynamic relocations for run-time function
489 pointer initialization. */
490
491 if ((!h->non_got_ref
492 || eh->func_pointer_refcount > 0
493 || (h->root.type == bfd_link_hash_undefweak
494 && !resolved_to_zero))
495 && ((h->def_dynamic
496 && !h->def_regular)
497 || (htab->elf.dynamic_sections_created
498 && (h->root.type == bfd_link_hash_undefweak
499 || h->root.type == bfd_link_hash_undefined))))
500 {
501 /* Make sure this symbol is output as a dynamic symbol.
502 Undefined weak syms won't yet be marked as dynamic. */
503 if (h->dynindx == -1
504 && !h->forced_local
505 && !resolved_to_zero
506 && h->root.type == bfd_link_hash_undefweak
507 && ! bfd_elf_link_record_dynamic_symbol (info, h))
508 return FALSE;
509
510 /* If that succeeded, we know we'll be keeping all the
511 relocs. */
512 if (h->dynindx != -1)
513 goto keep;
514 }
515
516 eh->dyn_relocs = NULL;
517 eh->func_pointer_refcount = 0;
518
519 keep: ;
520 }
521
522 /* Finally, allocate space. */
523 for (p = eh->dyn_relocs; p != NULL; p = p->next)
524 {
525 asection *sreloc;
526
527 sreloc = elf_section_data (p->sec)->sreloc;
528
529 BFD_ASSERT (sreloc != NULL);
530 sreloc->size += p->count * htab->sizeof_reloc;
531 }
532
533 return TRUE;
534 }
535
536 /* Find any dynamic relocs that apply to read-only sections. */
537
538 bfd_boolean
539 _bfd_x86_elf_readonly_dynrelocs (struct elf_link_hash_entry *h,
540 void *inf)
541 {
542 struct elf_x86_link_hash_entry *eh;
543 struct elf_dyn_relocs *p;
544
545 /* Skip local IFUNC symbols. */
546 if (h->forced_local && h->type == STT_GNU_IFUNC)
547 return TRUE;
548
549 eh = (struct elf_x86_link_hash_entry *) h;
550 for (p = eh->dyn_relocs; p != NULL; p = p->next)
551 {
552 asection *s = p->sec->output_section;
553
554 if (s != NULL && (s->flags & SEC_READONLY) != 0)
555 {
556 struct bfd_link_info *info = (struct bfd_link_info *) inf;
557
558 info->flags |= DF_TEXTREL;
559
560 if ((info->warn_shared_textrel && bfd_link_pic (info))
561 || info->error_textrel)
562 /* xgettext:c-format */
563 info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"),
564 p->sec->owner, h->root.root.string,
565 p->sec);
566
567 /* Not an error, just cut short the traversal. */
568 return FALSE;
569 }
570 }
571 return TRUE;
572 }
573
574 /* Allocate space in .plt, .got and associated reloc sections for
575 local dynamic relocs. */
576
577 static bfd_boolean
578 elf_x86_allocate_local_dynreloc (void **slot, void *inf)
579 {
580 struct elf_link_hash_entry *h
581 = (struct elf_link_hash_entry *) *slot;
582
583 if (h->type != STT_GNU_IFUNC
584 || !h->def_regular
585 || !h->ref_regular
586 || !h->forced_local
587 || h->root.type != bfd_link_hash_defined)
588 abort ();
589
590 return elf_x86_allocate_dynrelocs (h, inf);
591 }
592
593 /* Find and/or create a hash entry for local symbol. */
594
595 struct elf_link_hash_entry *
596 _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab,
597 bfd *abfd, const Elf_Internal_Rela *rel,
598 bfd_boolean create)
599 {
600 struct elf_x86_link_hash_entry e, *ret;
601 asection *sec = abfd->sections;
602 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id,
603 htab->r_sym (rel->r_info));
604 void **slot;
605
606 e.elf.indx = sec->id;
607 e.elf.dynstr_index = htab->r_sym (rel->r_info);
608 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h,
609 create ? INSERT : NO_INSERT);
610
611 if (!slot)
612 return NULL;
613
614 if (*slot)
615 {
616 ret = (struct elf_x86_link_hash_entry *) *slot;
617 return &ret->elf;
618 }
619
620 ret = (struct elf_x86_link_hash_entry *)
621 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory,
622 sizeof (struct elf_x86_link_hash_entry));
623 if (ret)
624 {
625 memset (ret, 0, sizeof (*ret));
626 ret->elf.indx = sec->id;
627 ret->elf.dynstr_index = htab->r_sym (rel->r_info);
628 ret->elf.dynindx = -1;
629 ret->plt_got.offset = (bfd_vma) -1;
630 *slot = ret;
631 }
632 return &ret->elf;
633 }
634
635 /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN
636 SYNC WITH _bfd_elf_link_hash_newfunc. */
637
638 struct bfd_hash_entry *
639 _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry,
640 struct bfd_hash_table *table,
641 const char *string)
642 {
643 /* Allocate the structure if it has not already been allocated by a
644 subclass. */
645 if (entry == NULL)
646 {
647 entry = (struct bfd_hash_entry *)
648 bfd_hash_allocate (table,
649 sizeof (struct elf_x86_link_hash_entry));
650 if (entry == NULL)
651 return entry;
652 }
653
654 /* Call the allocation method of the superclass. */
655 entry = _bfd_link_hash_newfunc (entry, table, string);
656 if (entry != NULL)
657 {
658 struct elf_x86_link_hash_entry *eh
659 = (struct elf_x86_link_hash_entry *) entry;
660 struct elf_link_hash_table *htab
661 = (struct elf_link_hash_table *) table;
662
663 memset (&eh->elf.size, 0,
664 (sizeof (struct elf_x86_link_hash_entry)
665 - offsetof (struct elf_link_hash_entry, size)));
666 /* Set local fields. */
667 eh->elf.indx = -1;
668 eh->elf.dynindx = -1;
669 eh->elf.got = htab->init_got_refcount;
670 eh->elf.plt = htab->init_plt_refcount;
671 /* Assume that we have been called by a non-ELF symbol reader.
672 This flag is then reset by the code which reads an ELF input
673 file. This ensures that a symbol created by a non-ELF symbol
674 reader will have the flag set correctly. */
675 eh->elf.non_elf = 1;
676 eh->plt_second.offset = (bfd_vma) -1;
677 eh->plt_got.offset = (bfd_vma) -1;
678 eh->tlsdesc_got = (bfd_vma) -1;
679 }
680
681 return entry;
682 }
683
684 /* Compute a hash of a local hash entry. We use elf_link_hash_entry
685 for local symbol so that we can handle local STT_GNU_IFUNC symbols
686 as global symbol. We reuse indx and dynstr_index for local symbol
687 hash since they aren't used by global symbols in this backend. */
688
689 hashval_t
690 _bfd_x86_elf_local_htab_hash (const void *ptr)
691 {
692 struct elf_link_hash_entry *h
693 = (struct elf_link_hash_entry *) ptr;
694 return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index);
695 }
696
697 /* Compare local hash entries. */
698
699 int
700 _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2)
701 {
702 struct elf_link_hash_entry *h1
703 = (struct elf_link_hash_entry *) ptr1;
704 struct elf_link_hash_entry *h2
705 = (struct elf_link_hash_entry *) ptr2;
706
707 return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index;
708 }
709
710 /* Destroy an x86 ELF linker hash table. */
711
712 static void
713 elf_x86_link_hash_table_free (bfd *obfd)
714 {
715 struct elf_x86_link_hash_table *htab
716 = (struct elf_x86_link_hash_table *) obfd->link.hash;
717
718 if (htab->loc_hash_table)
719 htab_delete (htab->loc_hash_table);
720 if (htab->loc_hash_memory)
721 objalloc_free ((struct objalloc *) htab->loc_hash_memory);
722 _bfd_elf_link_hash_table_free (obfd);
723 }
724
725 static bfd_boolean
726 elf_i386_is_reloc_section (const char *secname)
727 {
728 return CONST_STRNEQ (secname, ".rel");
729 }
730
731 static bfd_boolean
732 elf_x86_64_is_reloc_section (const char *secname)
733 {
734 return CONST_STRNEQ (secname, ".rela");
735 }
736
737 /* Create an x86 ELF linker hash table. */
738
739 struct bfd_link_hash_table *
740 _bfd_x86_elf_link_hash_table_create (bfd *abfd)
741 {
742 struct elf_x86_link_hash_table *ret;
743 const struct elf_backend_data *bed;
744 bfd_size_type amt = sizeof (struct elf_x86_link_hash_table);
745
746 ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt);
747 if (ret == NULL)
748 return NULL;
749
750 bed = get_elf_backend_data (abfd);
751 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd,
752 _bfd_x86_elf_link_hash_newfunc,
753 sizeof (struct elf_x86_link_hash_entry),
754 bed->target_id))
755 {
756 free (ret);
757 return NULL;
758 }
759
760 if (bed->target_id == X86_64_ELF_DATA)
761 {
762 ret->is_reloc_section = elf_x86_64_is_reloc_section;
763 ret->dt_reloc = DT_RELA;
764 ret->dt_reloc_sz = DT_RELASZ;
765 ret->dt_reloc_ent = DT_RELAENT;
766 ret->got_entry_size = 8;
767 ret->tls_get_addr = "__tls_get_addr";
768 }
769 if (ABI_64_P (abfd))
770 {
771 ret->sizeof_reloc = sizeof (Elf64_External_Rela);
772 ret->pointer_r_type = R_X86_64_64;
773 ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER;
774 ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER;
775 }
776 else
777 {
778 if (bed->target_id == X86_64_ELF_DATA)
779 {
780 ret->sizeof_reloc = sizeof (Elf32_External_Rela);
781 ret->pointer_r_type = R_X86_64_32;
782 ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER;
783 ret->dynamic_interpreter_size
784 = sizeof ELFX32_DYNAMIC_INTERPRETER;
785 }
786 else
787 {
788 ret->is_reloc_section = elf_i386_is_reloc_section;
789 ret->dt_reloc = DT_REL;
790 ret->dt_reloc_sz = DT_RELSZ;
791 ret->dt_reloc_ent = DT_RELENT;
792 ret->sizeof_reloc = sizeof (Elf32_External_Rel);
793 ret->got_entry_size = 4;
794 ret->pointer_r_type = R_386_32;
795 ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER;
796 ret->dynamic_interpreter_size
797 = sizeof ELF32_DYNAMIC_INTERPRETER;
798 ret->tls_get_addr = "___tls_get_addr";
799 }
800 }
801 ret->target_id = bed->target_id;
802
803 ret->loc_hash_table = htab_try_create (1024,
804 _bfd_x86_elf_local_htab_hash,
805 _bfd_x86_elf_local_htab_eq,
806 NULL);
807 ret->loc_hash_memory = objalloc_create ();
808 if (!ret->loc_hash_table || !ret->loc_hash_memory)
809 {
810 elf_x86_link_hash_table_free (abfd);
811 return NULL;
812 }
813 ret->elf.root.hash_table_free = elf_x86_link_hash_table_free;
814
815 return &ret->elf.root;
816 }
817
818 /* Sort relocs into address order. */
819
820 int
821 _bfd_x86_elf_compare_relocs (const void *ap, const void *bp)
822 {
823 const arelent *a = * (const arelent **) ap;
824 const arelent *b = * (const arelent **) bp;
825
826 if (a->address > b->address)
827 return 1;
828 else if (a->address < b->address)
829 return -1;
830 else
831 return 0;
832 }
833
834 bfd_boolean
835 _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
836 {
837 if (!bfd_link_relocatable (info))
838 {
839 /* Check for __tls_get_addr reference. */
840 struct elf_x86_link_hash_table *htab;
841 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
842 htab = elf_x86_hash_table (info, bed->target_id);
843 if (htab)
844 {
845 struct elf_link_hash_entry *h;
846
847 h = elf_link_hash_lookup (elf_hash_table (info),
848 htab->tls_get_addr,
849 FALSE, FALSE, FALSE);
850 if (h != NULL)
851 elf_x86_hash_entry (h)->tls_get_addr = 1;
852
853 /* "__ehdr_start" will be defined by linker as a hidden symbol
854 later if it is referenced and not defined. */
855 h = elf_link_hash_lookup (elf_hash_table (info),
856 "__ehdr_start",
857 FALSE, FALSE, FALSE);
858 if (h != NULL
859 && (h->root.type == bfd_link_hash_new
860 || h->root.type == bfd_link_hash_undefined
861 || h->root.type == bfd_link_hash_undefweak
862 || h->root.type == bfd_link_hash_common))
863 {
864 elf_x86_hash_entry (h)->local_ref = 2;
865 elf_x86_hash_entry (h)->linker_def = 1;
866 }
867 }
868 }
869
870 /* Invoke the regular ELF backend linker to do all the work. */
871 return _bfd_elf_link_check_relocs (abfd, info);
872 }
873
874 /* Set the sizes of the dynamic sections. */
875
876 bfd_boolean
877 _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
878 struct bfd_link_info *info)
879 {
880 struct elf_x86_link_hash_table *htab;
881 bfd *dynobj;
882 asection *s;
883 bfd_boolean relocs;
884 bfd *ibfd;
885 const struct elf_backend_data *bed
886 = get_elf_backend_data (output_bfd);
887
888 htab = elf_x86_hash_table (info, bed->target_id);
889 if (htab == NULL)
890 return FALSE;
891 dynobj = htab->elf.dynobj;
892 if (dynobj == NULL)
893 abort ();
894
895 /* Set up .got offsets for local syms, and space for local dynamic
896 relocs. */
897 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
898 {
899 bfd_signed_vma *local_got;
900 bfd_signed_vma *end_local_got;
901 char *local_tls_type;
902 bfd_vma *local_tlsdesc_gotent;
903 bfd_size_type locsymcount;
904 Elf_Internal_Shdr *symtab_hdr;
905 asection *srel;
906
907 if (! is_x86_elf (ibfd, htab))
908 continue;
909
910 for (s = ibfd->sections; s != NULL; s = s->next)
911 {
912 struct elf_dyn_relocs *p;
913
914 for (p = ((struct elf_dyn_relocs *)
915 elf_section_data (s)->local_dynrel);
916 p != NULL;
917 p = p->next)
918 {
919 if (!bfd_is_abs_section (p->sec)
920 && bfd_is_abs_section (p->sec->output_section))
921 {
922 /* Input section has been discarded, either because
923 it is a copy of a linkonce section or due to
924 linker script /DISCARD/, so we'll be discarding
925 the relocs too. */
926 }
927 else if (htab->is_vxworks
928 && strcmp (p->sec->output_section->name,
929 ".tls_vars") == 0)
930 {
931 /* Relocations in vxworks .tls_vars sections are
932 handled specially by the loader. */
933 }
934 else if (p->count != 0)
935 {
936 srel = elf_section_data (p->sec)->sreloc;
937 srel->size += p->count * htab->sizeof_reloc;
938 if ((p->sec->output_section->flags & SEC_READONLY) != 0
939 && (info->flags & DF_TEXTREL) == 0)
940 {
941 info->flags |= DF_TEXTREL;
942 if ((info->warn_shared_textrel && bfd_link_pic (info))
943 || info->error_textrel)
944 /* xgettext:c-format */
945 info->callbacks->einfo (_("%P: %B: warning: relocation in readonly section `%A'\n"),
946 p->sec->owner, p->sec);
947 }
948 }
949 }
950 }
951
952 local_got = elf_local_got_refcounts (ibfd);
953 if (!local_got)
954 continue;
955
956 symtab_hdr = &elf_symtab_hdr (ibfd);
957 locsymcount = symtab_hdr->sh_info;
958 end_local_got = local_got + locsymcount;
959 local_tls_type = elf_x86_local_got_tls_type (ibfd);
960 local_tlsdesc_gotent = elf_x86_local_tlsdesc_gotent (ibfd);
961 s = htab->elf.sgot;
962 srel = htab->elf.srelgot;
963 for (; local_got < end_local_got;
964 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
965 {
966 *local_tlsdesc_gotent = (bfd_vma) -1;
967 if (*local_got > 0)
968 {
969 if (GOT_TLS_GDESC_P (*local_tls_type))
970 {
971 *local_tlsdesc_gotent = htab->elf.sgotplt->size
972 - elf_x86_compute_jump_table_size (htab);
973 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
974 *local_got = (bfd_vma) -2;
975 }
976 if (! GOT_TLS_GDESC_P (*local_tls_type)
977 || GOT_TLS_GD_P (*local_tls_type))
978 {
979 *local_got = s->size;
980 s->size += htab->got_entry_size;
981 if (GOT_TLS_GD_P (*local_tls_type)
982 || *local_tls_type == GOT_TLS_IE_BOTH)
983 s->size += htab->got_entry_size;
984 }
985 if (bfd_link_pic (info)
986 || GOT_TLS_GD_ANY_P (*local_tls_type)
987 || (*local_tls_type & GOT_TLS_IE))
988 {
989 if (*local_tls_type == GOT_TLS_IE_BOTH)
990 srel->size += 2 * htab->sizeof_reloc;
991 else if (GOT_TLS_GD_P (*local_tls_type)
992 || ! GOT_TLS_GDESC_P (*local_tls_type))
993 srel->size += htab->sizeof_reloc;
994 if (GOT_TLS_GDESC_P (*local_tls_type))
995 {
996 htab->elf.srelplt->size += htab->sizeof_reloc;
997 if (bed->target_id == X86_64_ELF_DATA)
998 htab->tlsdesc_plt = (bfd_vma) -1;
999 }
1000 }
1001 }
1002 else
1003 *local_got = (bfd_vma) -1;
1004 }
1005 }
1006
1007 if (htab->tls_ld_or_ldm_got.refcount > 0)
1008 {
1009 /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM
1010 or R_X86_64_TLSLD relocs. */
1011 htab->tls_ld_or_ldm_got.offset = htab->elf.sgot->size;
1012 htab->elf.sgot->size += 2 * htab->got_entry_size;
1013 htab->elf.srelgot->size += htab->sizeof_reloc;
1014 }
1015 else
1016 htab->tls_ld_or_ldm_got.offset = -1;
1017
1018 /* Allocate global sym .plt and .got entries, and space for global
1019 sym dynamic relocs. */
1020 elf_link_hash_traverse (&htab->elf, elf_x86_allocate_dynrelocs,
1021 info);
1022
1023 /* Allocate .plt and .got entries, and space for local symbols. */
1024 htab_traverse (htab->loc_hash_table, elf_x86_allocate_local_dynreloc,
1025 info);
1026
1027 /* For every jump slot reserved in the sgotplt, reloc_count is
1028 incremented. However, when we reserve space for TLS descriptors,
1029 it's not incremented, so in order to compute the space reserved
1030 for them, it suffices to multiply the reloc count by the jump
1031 slot size.
1032
1033 PR ld/13302: We start next_irelative_index at the end of .rela.plt
1034 so that R_{386,X86_64}_IRELATIVE entries come last. */
1035 if (htab->elf.srelplt)
1036 {
1037 htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
1038 htab->sgotplt_jump_table_size
1039 = elf_x86_compute_jump_table_size (htab);
1040 htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
1041 }
1042 else if (htab->elf.irelplt)
1043 htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
1044
1045 if (htab->tlsdesc_plt)
1046 {
1047 /* NB: tlsdesc_plt is set only for x86-64. If we're not using
1048 lazy TLS relocations, don't generate the PLT and GOT entries
1049 they require. */
1050 if ((info->flags & DF_BIND_NOW))
1051 htab->tlsdesc_plt = 0;
1052 else
1053 {
1054 htab->tlsdesc_got = htab->elf.sgot->size;
1055 htab->elf.sgot->size += htab->got_entry_size;
1056 /* Reserve room for the initial entry.
1057 FIXME: we could probably do away with it in this case. */
1058 if (htab->elf.splt->size == 0)
1059 htab->elf.splt->size = htab->plt.plt_entry_size;
1060 htab->tlsdesc_plt = htab->elf.splt->size;
1061 htab->elf.splt->size += htab->plt.plt_entry_size;
1062 }
1063 }
1064
1065 if (htab->elf.sgotplt)
1066 {
1067 /* Don't allocate .got.plt section if there are no GOT nor PLT
1068 entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */
1069 if ((htab->elf.hgot == NULL
1070 || !htab->elf.hgot->ref_regular_nonweak)
1071 && (htab->elf.sgotplt->size == bed->got_header_size)
1072 && (htab->elf.splt == NULL
1073 || htab->elf.splt->size == 0)
1074 && (htab->elf.sgot == NULL
1075 || htab->elf.sgot->size == 0)
1076 && (htab->elf.iplt == NULL
1077 || htab->elf.iplt->size == 0)
1078 && (htab->elf.igotplt == NULL
1079 || htab->elf.igotplt->size == 0))
1080 htab->elf.sgotplt->size = 0;
1081 }
1082
1083 if (_bfd_elf_eh_frame_present (info))
1084 {
1085 if (htab->plt_eh_frame != NULL
1086 && htab->elf.splt != NULL
1087 && htab->elf.splt->size != 0
1088 && !bfd_is_abs_section (htab->elf.splt->output_section))
1089 htab->plt_eh_frame->size = htab->plt.eh_frame_plt_size;
1090
1091 if (htab->plt_got_eh_frame != NULL
1092 && htab->plt_got != NULL
1093 && htab->plt_got->size != 0
1094 && !bfd_is_abs_section (htab->plt_got->output_section))
1095 htab->plt_got_eh_frame->size
1096 = htab->non_lazy_plt->eh_frame_plt_size;
1097
1098 /* Unwind info for the second PLT and .plt.got sections are
1099 identical. */
1100 if (htab->plt_second_eh_frame != NULL
1101 && htab->plt_second != NULL
1102 && htab->plt_second->size != 0
1103 && !bfd_is_abs_section (htab->plt_second->output_section))
1104 htab->plt_second_eh_frame->size
1105 = htab->non_lazy_plt->eh_frame_plt_size;
1106 }
1107
1108 /* We now have determined the sizes of the various dynamic sections.
1109 Allocate memory for them. */
1110 relocs = FALSE;
1111 for (s = dynobj->sections; s != NULL; s = s->next)
1112 {
1113 bfd_boolean strip_section = TRUE;
1114
1115 if ((s->flags & SEC_LINKER_CREATED) == 0)
1116 continue;
1117
1118 if (s == htab->elf.splt
1119 || s == htab->elf.sgot)
1120 {
1121 /* Strip this section if we don't need it; see the
1122 comment below. */
1123 /* We'd like to strip these sections if they aren't needed, but if
1124 we've exported dynamic symbols from them we must leave them.
1125 It's too late to tell BFD to get rid of the symbols. */
1126
1127 if (htab->elf.hplt != NULL)
1128 strip_section = FALSE;
1129 }
1130 else if (s == htab->elf.sgotplt
1131 || s == htab->elf.iplt
1132 || s == htab->elf.igotplt
1133 || s == htab->plt_second
1134 || s == htab->plt_got
1135 || s == htab->plt_eh_frame
1136 || s == htab->plt_got_eh_frame
1137 || s == htab->plt_second_eh_frame
1138 || s == htab->elf.sdynbss
1139 || s == htab->elf.sdynrelro)
1140 {
1141 /* Strip these too. */
1142 }
1143 else if (htab->is_reloc_section (bfd_get_section_name (dynobj, s)))
1144 {
1145 if (s->size != 0
1146 && s != htab->elf.srelplt
1147 && s != htab->srelplt2)
1148 relocs = TRUE;
1149
1150 /* We use the reloc_count field as a counter if we need
1151 to copy relocs into the output file. */
1152 if (s != htab->elf.srelplt)
1153 s->reloc_count = 0;
1154 }
1155 else
1156 {
1157 /* It's not one of our sections, so don't allocate space. */
1158 continue;
1159 }
1160
1161 if (s->size == 0)
1162 {
1163 /* If we don't need this section, strip it from the
1164 output file. This is mostly to handle .rel.bss and
1165 .rel.plt. We must create both sections in
1166 create_dynamic_sections, because they must be created
1167 before the linker maps input sections to output
1168 sections. The linker does that before
1169 adjust_dynamic_symbol is called, and it is that
1170 function which decides whether anything needs to go
1171 into these sections. */
1172 if (strip_section)
1173 s->flags |= SEC_EXCLUDE;
1174 continue;
1175 }
1176
1177 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1178 continue;
1179
1180 /* Allocate memory for the section contents. We use bfd_zalloc
1181 here in case unused entries are not reclaimed before the
1182 section's contents are written out. This should not happen,
1183 but this way if it does, we get a R_386_NONE or R_X86_64_NONE
1184 reloc instead of garbage. */
1185 s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size);
1186 if (s->contents == NULL)
1187 return FALSE;
1188 }
1189
1190 if (htab->plt_eh_frame != NULL
1191 && htab->plt_eh_frame->contents != NULL)
1192 {
1193 memcpy (htab->plt_eh_frame->contents,
1194 htab->plt.eh_frame_plt,
1195 htab->plt_eh_frame->size);
1196 bfd_put_32 (dynobj, htab->elf.splt->size,
1197 htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET);
1198 }
1199
1200 if (htab->plt_got_eh_frame != NULL
1201 && htab->plt_got_eh_frame->contents != NULL)
1202 {
1203 memcpy (htab->plt_got_eh_frame->contents,
1204 htab->non_lazy_plt->eh_frame_plt,
1205 htab->plt_got_eh_frame->size);
1206 bfd_put_32 (dynobj, htab->plt_got->size,
1207 (htab->plt_got_eh_frame->contents
1208 + PLT_FDE_LEN_OFFSET));
1209 }
1210
1211 if (htab->plt_second_eh_frame != NULL
1212 && htab->plt_second_eh_frame->contents != NULL)
1213 {
1214 memcpy (htab->plt_second_eh_frame->contents,
1215 htab->non_lazy_plt->eh_frame_plt,
1216 htab->plt_second_eh_frame->size);
1217 bfd_put_32 (dynobj, htab->plt_second->size,
1218 (htab->plt_second_eh_frame->contents
1219 + PLT_FDE_LEN_OFFSET));
1220 }
1221
1222 if (htab->elf.dynamic_sections_created)
1223 {
1224 /* Add some entries to the .dynamic section. We fill in the
1225 values later, in elf_{i386,x86_64}_finish_dynamic_sections,
1226 but we must add the entries now so that we get the correct
1227 size for the .dynamic section. The DT_DEBUG entry is filled
1228 in by the dynamic linker and used by the debugger. */
1229 #define add_dynamic_entry(TAG, VAL) \
1230 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1231
1232 if (bfd_link_executable (info))
1233 {
1234 if (!add_dynamic_entry (DT_DEBUG, 0))
1235 return FALSE;
1236 }
1237
1238 if (htab->elf.splt->size != 0)
1239 {
1240 /* DT_PLTGOT is used by prelink even if there is no PLT
1241 relocation. */
1242 if (!add_dynamic_entry (DT_PLTGOT, 0))
1243 return FALSE;
1244 }
1245
1246 if (htab->elf.srelplt->size != 0)
1247 {
1248 if (!add_dynamic_entry (DT_PLTRELSZ, 0)
1249 || !add_dynamic_entry (DT_PLTREL, htab->dt_reloc)
1250 || !add_dynamic_entry (DT_JMPREL, 0))
1251 return FALSE;
1252 }
1253
1254 if (htab->tlsdesc_plt
1255 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
1256 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
1257 return FALSE;
1258
1259 if (relocs)
1260 {
1261 if (!add_dynamic_entry (htab->dt_reloc, 0)
1262 || !add_dynamic_entry (htab->dt_reloc_sz, 0)
1263 || !add_dynamic_entry (htab->dt_reloc_ent,
1264 htab->sizeof_reloc))
1265 return FALSE;
1266
1267 /* If any dynamic relocs apply to a read-only section,
1268 then we need a DT_TEXTREL entry. */
1269 if ((info->flags & DF_TEXTREL) == 0)
1270 elf_link_hash_traverse (&htab->elf,
1271 _bfd_x86_elf_readonly_dynrelocs,
1272 info);
1273
1274 if ((info->flags & DF_TEXTREL) != 0)
1275 {
1276 if (htab->readonly_dynrelocs_against_ifunc)
1277 {
1278 info->callbacks->einfo
1279 (_("%P%X: read-only segment has dynamic IFUNC relocations; recompile with -fPIC\n"));
1280 bfd_set_error (bfd_error_bad_value);
1281 return FALSE;
1282 }
1283
1284 if (!add_dynamic_entry (DT_TEXTREL, 0))
1285 return FALSE;
1286 }
1287 }
1288 if (htab->is_vxworks
1289 && !elf_vxworks_add_dynamic_entries (output_bfd, info))
1290 return FALSE;
1291 }
1292 #undef add_dynamic_entry
1293
1294 return TRUE;
1295 }
1296
1297 bfd_boolean
1298 _bfd_x86_elf_always_size_sections (bfd *output_bfd,
1299 struct bfd_link_info *info)
1300 {
1301 asection *tls_sec = elf_hash_table (info)->tls_sec;
1302
1303 if (tls_sec)
1304 {
1305 struct elf_link_hash_entry *tlsbase;
1306
1307 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1308 "_TLS_MODULE_BASE_",
1309 FALSE, FALSE, FALSE);
1310
1311 if (tlsbase && tlsbase->type == STT_TLS)
1312 {
1313 struct elf_x86_link_hash_table *htab;
1314 struct bfd_link_hash_entry *bh = NULL;
1315 const struct elf_backend_data *bed
1316 = get_elf_backend_data (output_bfd);
1317
1318 htab = elf_x86_hash_table (info, bed->target_id);
1319 if (htab == NULL)
1320 return FALSE;
1321
1322 if (!(_bfd_generic_link_add_one_symbol
1323 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1324 tls_sec, 0, NULL, FALSE,
1325 bed->collect, &bh)))
1326 return FALSE;
1327
1328 htab->tls_module_base = bh;
1329
1330 tlsbase = (struct elf_link_hash_entry *)bh;
1331 tlsbase->def_regular = 1;
1332 tlsbase->other = STV_HIDDEN;
1333 tlsbase->root.linker_def = 1;
1334 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
1335 }
1336 }
1337
1338 return TRUE;
1339 }
1340
1341 void
1342 _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h,
1343 const Elf_Internal_Sym *isym,
1344 bfd_boolean definition,
1345 bfd_boolean dynamic ATTRIBUTE_UNUSED)
1346 {
1347 if (definition)
1348 {
1349 struct elf_x86_link_hash_entry *eh
1350 = (struct elf_x86_link_hash_entry *) h;
1351 eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other)
1352 == STV_PROTECTED);
1353 }
1354 }
1355
1356 /* Copy the extra info we tack onto an elf_link_hash_entry. */
1357
1358 void
1359 _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info,
1360 struct elf_link_hash_entry *dir,
1361 struct elf_link_hash_entry *ind)
1362 {
1363 struct elf_x86_link_hash_entry *edir, *eind;
1364
1365 edir = (struct elf_x86_link_hash_entry *) dir;
1366 eind = (struct elf_x86_link_hash_entry *) ind;
1367
1368 if (eind->dyn_relocs != NULL)
1369 {
1370 if (edir->dyn_relocs != NULL)
1371 {
1372 struct elf_dyn_relocs **pp;
1373 struct elf_dyn_relocs *p;
1374
1375 /* Add reloc counts against the indirect sym to the direct sym
1376 list. Merge any entries against the same section. */
1377 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
1378 {
1379 struct elf_dyn_relocs *q;
1380
1381 for (q = edir->dyn_relocs; q != NULL; q = q->next)
1382 if (q->sec == p->sec)
1383 {
1384 q->pc_count += p->pc_count;
1385 q->count += p->count;
1386 *pp = p->next;
1387 break;
1388 }
1389 if (q == NULL)
1390 pp = &p->next;
1391 }
1392 *pp = edir->dyn_relocs;
1393 }
1394
1395 edir->dyn_relocs = eind->dyn_relocs;
1396 eind->dyn_relocs = NULL;
1397 }
1398
1399 if (ind->root.type == bfd_link_hash_indirect
1400 && dir->got.refcount <= 0)
1401 {
1402 edir->tls_type = eind->tls_type;
1403 eind->tls_type = GOT_UNKNOWN;
1404 }
1405
1406 /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will
1407 generate a R_386_COPY reloc. */
1408 edir->gotoff_ref |= eind->gotoff_ref;
1409
1410 edir->has_got_reloc |= eind->has_got_reloc;
1411 edir->has_non_got_reloc |= eind->has_non_got_reloc;
1412
1413 if (ELIMINATE_COPY_RELOCS
1414 && ind->root.type != bfd_link_hash_indirect
1415 && dir->dynamic_adjusted)
1416 {
1417 /* If called to transfer flags for a weakdef during processing
1418 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
1419 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
1420 if (dir->versioned != versioned_hidden)
1421 dir->ref_dynamic |= ind->ref_dynamic;
1422 dir->ref_regular |= ind->ref_regular;
1423 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
1424 dir->needs_plt |= ind->needs_plt;
1425 dir->pointer_equality_needed |= ind->pointer_equality_needed;
1426 }
1427 else
1428 {
1429 if (eind->func_pointer_refcount > 0)
1430 {
1431 edir->func_pointer_refcount += eind->func_pointer_refcount;
1432 eind->func_pointer_refcount = 0;
1433 }
1434
1435 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
1436 }
1437 }
1438
1439 /* Remove undefined weak symbol from the dynamic symbol table if it
1440 is resolved to 0. */
1441
1442 bfd_boolean
1443 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
1444 struct elf_link_hash_entry *h)
1445 {
1446 if (h->dynindx != -1
1447 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h)))
1448 {
1449 h->dynindx = -1;
1450 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
1451 h->dynstr_index);
1452 }
1453 return TRUE;
1454 }
1455
1456 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1457
1458 bfd_boolean
1459 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1460 {
1461 if (h->plt.offset != (bfd_vma) -1
1462 && !h->def_regular
1463 && !h->pointer_equality_needed)
1464 return FALSE;
1465
1466 return _bfd_elf_hash_symbol (h);
1467 }
1468
1469 /* Adjust a symbol defined by a dynamic object and referenced by a
1470 regular object. The current definition is in some section of the
1471 dynamic object, but we're not including those sections. We have to
1472 change the definition to something the rest of the link can
1473 understand. */
1474
1475 bfd_boolean
1476 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1477 struct elf_link_hash_entry *h)
1478 {
1479 struct elf_x86_link_hash_table *htab;
1480 asection *s, *srel;
1481 struct elf_x86_link_hash_entry *eh;
1482 struct elf_dyn_relocs *p;
1483 const struct elf_backend_data *bed
1484 = get_elf_backend_data (info->output_bfd);
1485
1486 /* STT_GNU_IFUNC symbol must go through PLT. */
1487 if (h->type == STT_GNU_IFUNC)
1488 {
1489 /* All local STT_GNU_IFUNC references must be treate as local
1490 calls via local PLT. */
1491 if (h->ref_regular
1492 && SYMBOL_CALLS_LOCAL (info, h))
1493 {
1494 bfd_size_type pc_count = 0, count = 0;
1495 struct elf_dyn_relocs **pp;
1496
1497 eh = (struct elf_x86_link_hash_entry *) h;
1498 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1499 {
1500 pc_count += p->pc_count;
1501 p->count -= p->pc_count;
1502 p->pc_count = 0;
1503 count += p->count;
1504 if (p->count == 0)
1505 *pp = p->next;
1506 else
1507 pp = &p->next;
1508 }
1509
1510 if (pc_count || count)
1511 {
1512 h->non_got_ref = 1;
1513 if (pc_count)
1514 {
1515 /* Increment PLT reference count only for PC-relative
1516 references. */
1517 h->needs_plt = 1;
1518 if (h->plt.refcount <= 0)
1519 h->plt.refcount = 1;
1520 else
1521 h->plt.refcount += 1;
1522 }
1523 }
1524 }
1525
1526 if (h->plt.refcount <= 0)
1527 {
1528 h->plt.offset = (bfd_vma) -1;
1529 h->needs_plt = 0;
1530 }
1531 return TRUE;
1532 }
1533
1534 /* If this is a function, put it in the procedure linkage table. We
1535 will fill in the contents of the procedure linkage table later,
1536 when we know the address of the .got section. */
1537 if (h->type == STT_FUNC
1538 || h->needs_plt)
1539 {
1540 if (h->plt.refcount <= 0
1541 || SYMBOL_CALLS_LOCAL (info, h)
1542 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1543 && h->root.type == bfd_link_hash_undefweak))
1544 {
1545 /* This case can occur if we saw a PLT32 reloc in an input
1546 file, but the symbol was never referred to by a dynamic
1547 object, or if all references were garbage collected. In
1548 such a case, we don't actually need to build a procedure
1549 linkage table, and we can just do a PC32 reloc instead. */
1550 h->plt.offset = (bfd_vma) -1;
1551 h->needs_plt = 0;
1552 }
1553
1554 return TRUE;
1555 }
1556 else
1557 /* It's possible that we incorrectly decided a .plt reloc was needed
1558 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
1559 check_relocs. We can't decide accurately between function and
1560 non-function syms in check-relocs; Objects loaded later in
1561 the link may change h->type. So fix it now. */
1562 h->plt.offset = (bfd_vma) -1;
1563
1564 eh = (struct elf_x86_link_hash_entry *) h;
1565
1566 /* If this is a weak symbol, and there is a real definition, the
1567 processor independent code will have arranged for us to see the
1568 real definition first, and we can just use the same value. */
1569 if (h->u.weakdef != NULL)
1570 {
1571 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1572 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1573 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1574 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1575 if (ELIMINATE_COPY_RELOCS
1576 || info->nocopyreloc
1577 || SYMBOL_NO_COPYRELOC (info, eh))
1578 {
1579 /* NB: needs_copy is always 0 for i386. */
1580 h->non_got_ref = h->u.weakdef->non_got_ref;
1581 eh->needs_copy = h->u.weakdef->needs_copy;
1582 }
1583 return TRUE;
1584 }
1585
1586 /* This is a reference to a symbol defined by a dynamic object which
1587 is not a function. */
1588
1589 /* If we are creating a shared library, we must presume that the
1590 only references to the symbol are via the global offset table.
1591 For such cases we need not do anything here; the relocations will
1592 be handled correctly by relocate_section. */
1593 if (!bfd_link_executable (info))
1594 return TRUE;
1595
1596 /* If there are no references to this symbol that do not use the
1597 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
1598 reloc. NB: gotoff_ref is always 0 for x86-64. */
1599 if (!h->non_got_ref && !eh->gotoff_ref)
1600 return TRUE;
1601
1602 /* If -z nocopyreloc was given, we won't generate them either. */
1603 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
1604 {
1605 h->non_got_ref = 0;
1606 return TRUE;
1607 }
1608
1609 htab = elf_x86_hash_table (info, bed->target_id);
1610 if (htab == NULL)
1611 return FALSE;
1612
1613 /* If there aren't any dynamic relocs in read-only sections nor
1614 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
1615 avoid the copy reloc. This doesn't work on VxWorks, where we can
1616 not have dynamic relocations (other than copy and jump slot
1617 relocations) in an executable. */
1618 if (ELIMINATE_COPY_RELOCS
1619 && (bed->target_id == X86_64_ELF_DATA
1620 || (!eh->gotoff_ref
1621 && !htab->is_vxworks)))
1622 {
1623 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1624 {
1625 s = p->sec->output_section;
1626 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1627 break;
1628 }
1629
1630 /* If we didn't find any dynamic relocs in read-only sections,
1631 then we'll be keeping the dynamic relocs and avoiding the copy
1632 reloc. */
1633 if (p == NULL)
1634 {
1635 h->non_got_ref = 0;
1636 return TRUE;
1637 }
1638 }
1639
1640 /* We must allocate the symbol in our .dynbss section, which will
1641 become part of the .bss section of the executable. There will be
1642 an entry for this symbol in the .dynsym section. The dynamic
1643 object will contain position independent code, so all references
1644 from the dynamic object to this symbol will go through the global
1645 offset table. The dynamic linker will use the .dynsym entry to
1646 determine the address it must put in the global offset table, so
1647 both the dynamic object and the regular object will refer to the
1648 same memory location for the variable. */
1649
1650 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
1651 dynamic linker to copy the initial value out of the dynamic object
1652 and into the runtime process image. */
1653 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
1654 {
1655 s = htab->elf.sdynrelro;
1656 srel = htab->elf.sreldynrelro;
1657 }
1658 else
1659 {
1660 s = htab->elf.sdynbss;
1661 srel = htab->elf.srelbss;
1662 }
1663 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
1664 {
1665 srel->size += htab->sizeof_reloc;
1666 h->needs_copy = 1;
1667 }
1668
1669 return _bfd_elf_adjust_dynamic_copy (info, h, s);
1670 }
1671
1672 /* Return TRUE if a symbol is referenced locally. It is similar to
1673 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
1674 works in check_relocs. */
1675
1676 bfd_boolean
1677 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
1678 struct elf_link_hash_entry *h)
1679 {
1680 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1681 struct elf_x86_link_hash_table *htab
1682 = (struct elf_x86_link_hash_table *) info->hash;
1683
1684 if (eh->local_ref > 1)
1685 return TRUE;
1686
1687 if (eh->local_ref == 1)
1688 return FALSE;
1689
1690 /* Unversioned symbols defined in regular objects can be forced local
1691 by linker version script. A weak undefined symbol is forced local
1692 if
1693 1. It has non-default visibility. Or
1694 2. When building executable, there is no dynamic linker. Or
1695 3. or "-z nodynamic-undefined-weak" is used.
1696 */
1697 if (SYMBOL_REFERENCES_LOCAL (info, h)
1698 || (h->root.type == bfd_link_hash_undefweak
1699 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1700 || (bfd_link_executable (info)
1701 && htab->interp == NULL)
1702 || info->dynamic_undefined_weak == 0))
1703 || ((h->def_regular || ELF_COMMON_DEF_P (h))
1704 && h->versioned == unversioned
1705 && info->version_info != NULL
1706 && bfd_hide_sym_by_version (info->version_info,
1707 h->root.root.string)))
1708 {
1709 eh->local_ref = 2;
1710 return TRUE;
1711 }
1712
1713 eh->local_ref = 1;
1714 return FALSE;
1715 }
1716
1717 /* Return the section that should be marked against GC for a given
1718 relocation. */
1719
1720 asection *
1721 _bfd_x86_elf_gc_mark_hook (asection *sec,
1722 struct bfd_link_info *info,
1723 Elf_Internal_Rela *rel,
1724 struct elf_link_hash_entry *h,
1725 Elf_Internal_Sym *sym)
1726 {
1727 /* Compiler should optimize this out. */
1728 if (((unsigned int) R_X86_64_GNU_VTINHERIT
1729 != (unsigned int) R_386_GNU_VTINHERIT)
1730 || ((unsigned int) R_X86_64_GNU_VTENTRY
1731 != (unsigned int) R_386_GNU_VTENTRY))
1732 abort ();
1733
1734 if (h != NULL)
1735 switch (ELF32_R_TYPE (rel->r_info))
1736 {
1737 case R_X86_64_GNU_VTINHERIT:
1738 case R_X86_64_GNU_VTENTRY:
1739 return NULL;
1740 }
1741
1742 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
1743 }
1744
1745 static bfd_vma
1746 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
1747 bfd_vma off,
1748 bfd_vma offset ATTRIBUTE_UNUSED,
1749 bfd_vma got_addr)
1750 {
1751 return got_addr + off;
1752 }
1753
1754 static bfd_vma
1755 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
1756 bfd_vma off,
1757 bfd_vma offset,
1758 bfd_vma got_addr ATTRIBUTE_UNUSED)
1759 {
1760 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
1761 }
1762
1763 static bfd_boolean
1764 elf_i386_valid_plt_reloc_p (unsigned int type)
1765 {
1766 return (type == R_386_JUMP_SLOT
1767 || type == R_386_GLOB_DAT
1768 || type == R_386_IRELATIVE);
1769 }
1770
1771 static bfd_boolean
1772 elf_x86_64_valid_plt_reloc_p (unsigned int type)
1773 {
1774 return (type == R_X86_64_JUMP_SLOT
1775 || type == R_X86_64_GLOB_DAT
1776 || type == R_X86_64_IRELATIVE);
1777 }
1778
1779 long
1780 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
1781 long count,
1782 long relsize,
1783 bfd_vma got_addr,
1784 struct elf_x86_plt plts[],
1785 asymbol **dynsyms,
1786 asymbol **ret)
1787 {
1788 long size, i, n, len;
1789 int j;
1790 unsigned int plt_got_offset, plt_entry_size;
1791 asymbol *s;
1792 bfd_byte *plt_contents;
1793 long dynrelcount;
1794 arelent **dynrelbuf, *p;
1795 char *names;
1796 const struct elf_backend_data *bed;
1797 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
1798 bfd_vma);
1799 bfd_boolean (*valid_plt_reloc_p) (unsigned int);
1800
1801 if (count == 0)
1802 return -1;
1803
1804 dynrelbuf = (arelent **) bfd_malloc (relsize);
1805 if (dynrelbuf == NULL)
1806 return -1;
1807
1808 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
1809 dynsyms);
1810
1811 /* Sort the relocs by address. */
1812 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
1813 _bfd_x86_elf_compare_relocs);
1814
1815 size = count * sizeof (asymbol);
1816
1817 /* Allocate space for @plt suffixes. */
1818 n = 0;
1819 for (i = 0; i < dynrelcount; i++)
1820 {
1821 p = dynrelbuf[i];
1822 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
1823 if (p->addend != 0)
1824 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
1825 }
1826
1827 s = *ret = (asymbol *) bfd_zmalloc (size);
1828 if (s == NULL)
1829 goto bad_return;
1830
1831 bed = get_elf_backend_data (abfd);
1832
1833 if (bed->target_id == X86_64_ELF_DATA)
1834 {
1835 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
1836 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
1837 }
1838 else
1839 {
1840 get_plt_got_vma = elf_i386_get_plt_got_vma;
1841 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
1842 if (got_addr)
1843 {
1844 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
1845 address. */
1846 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
1847 if (sec != NULL)
1848 got_addr = sec->vma;
1849 else
1850 {
1851 sec = bfd_get_section_by_name (abfd, ".got");
1852 if (sec != NULL)
1853 got_addr = sec->vma;
1854 }
1855
1856 if (got_addr == (bfd_vma) -1)
1857 goto bad_return;
1858 }
1859 }
1860
1861 /* Check for each PLT section. */
1862 names = (char *) (s + count);
1863 size = 0;
1864 n = 0;
1865 for (j = 0; plts[j].name != NULL; j++)
1866 if ((plt_contents = plts[j].contents) != NULL)
1867 {
1868 long k;
1869 bfd_vma offset;
1870 asection *plt;
1871 struct elf_x86_plt *plt_p = &plts[j];
1872
1873 plt_got_offset = plt_p->plt_got_offset;
1874 plt_entry_size = plt_p->plt_entry_size;
1875
1876 plt = plt_p->sec;
1877
1878 if ((plt_p->type & plt_lazy))
1879 {
1880 /* Skip PLT0 in lazy PLT. */
1881 k = 1;
1882 offset = plt_entry_size;
1883 }
1884 else
1885 {
1886 k = 0;
1887 offset = 0;
1888 }
1889
1890 /* Check each PLT entry against dynamic relocations. */
1891 for (; k < plt_p->count; k++)
1892 {
1893 int off;
1894 bfd_vma got_vma;
1895 long min, max, mid;
1896
1897 /* Get the GOT offset for i386 or the PC-relative offset
1898 for x86-64, a signed 32-bit integer. */
1899 off = H_GET_32 (abfd, (plt_contents + offset
1900 + plt_got_offset));
1901 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
1902
1903 /* Binary search. */
1904 p = dynrelbuf[0];
1905 min = 0;
1906 max = dynrelcount;
1907 while ((min + 1) < max)
1908 {
1909 arelent *r;
1910
1911 mid = (min + max) / 2;
1912 r = dynrelbuf[mid];
1913 if (got_vma > r->address)
1914 min = mid;
1915 else if (got_vma < r->address)
1916 max = mid;
1917 else
1918 {
1919 p = r;
1920 break;
1921 }
1922 }
1923
1924 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
1925 if (got_vma == p->address
1926 && p->howto != NULL
1927 && valid_plt_reloc_p (p->howto->type))
1928 {
1929 *s = **p->sym_ptr_ptr;
1930 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
1931 set. Since we are defining a symbol, ensure one
1932 of them is set. */
1933 if ((s->flags & BSF_LOCAL) == 0)
1934 s->flags |= BSF_GLOBAL;
1935 s->flags |= BSF_SYNTHETIC;
1936 /* This is no longer a section symbol. */
1937 s->flags &= ~BSF_SECTION_SYM;
1938 s->section = plt;
1939 s->the_bfd = plt->owner;
1940 s->value = offset;
1941 s->udata.p = NULL;
1942 s->name = names;
1943 len = strlen ((*p->sym_ptr_ptr)->name);
1944 memcpy (names, (*p->sym_ptr_ptr)->name, len);
1945 names += len;
1946 if (p->addend != 0)
1947 {
1948 char buf[30], *a;
1949
1950 memcpy (names, "+0x", sizeof ("+0x") - 1);
1951 names += sizeof ("+0x") - 1;
1952 bfd_sprintf_vma (abfd, buf, p->addend);
1953 for (a = buf; *a == '0'; ++a)
1954 ;
1955 size = strlen (a);
1956 memcpy (names, a, size);
1957 names += size;
1958 }
1959 memcpy (names, "@plt", sizeof ("@plt"));
1960 names += sizeof ("@plt");
1961 n++;
1962 s++;
1963 }
1964 offset += plt_entry_size;
1965 }
1966 }
1967
1968 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
1969 if (n == 0)
1970 {
1971 bad_return:
1972 count = -1;
1973 }
1974 else
1975 count = n;
1976
1977 for (j = 0; plts[j].name != NULL; j++)
1978 if (plts[j].contents != NULL)
1979 free (plts[j].contents);
1980
1981 free (dynrelbuf);
1982
1983 return count;
1984 }
1985
1986 /* Parse x86 GNU properties. */
1987
1988 enum elf_property_kind
1989 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
1990 bfd_byte *ptr, unsigned int datasz)
1991 {
1992 elf_property *prop;
1993
1994 switch (type)
1995 {
1996 case GNU_PROPERTY_X86_ISA_1_USED:
1997 case GNU_PROPERTY_X86_ISA_1_NEEDED:
1998 case GNU_PROPERTY_X86_FEATURE_1_AND:
1999 if (datasz != 4)
2000 {
2001 _bfd_error_handler
2002 ((type == GNU_PROPERTY_X86_ISA_1_USED
2003 ? _("error: %B: <corrupt x86 ISA used size: 0x%x>")
2004 : (type == GNU_PROPERTY_X86_ISA_1_NEEDED
2005 ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>")
2006 : _("error: %B: <corrupt x86 feature size: 0x%x>"))),
2007 abfd, datasz);
2008 return property_corrupt;
2009 }
2010 prop = _bfd_elf_get_property (abfd, type, datasz);
2011 /* Combine properties of the same type. */
2012 prop->u.number |= bfd_h_get_32 (abfd, ptr);
2013 prop->pr_kind = property_number;
2014 break;
2015
2016 default:
2017 return property_ignored;
2018 }
2019
2020 return property_number;
2021 }
2022
2023 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2024 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2025 should be merged with ABFD. */
2026
2027 bfd_boolean
2028 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2029 bfd *abfd ATTRIBUTE_UNUSED,
2030 elf_property *aprop,
2031 elf_property *bprop)
2032 {
2033 unsigned int number, features;
2034 bfd_boolean updated = FALSE;
2035 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2036
2037 switch (pr_type)
2038 {
2039 case GNU_PROPERTY_X86_ISA_1_USED:
2040 case GNU_PROPERTY_X86_ISA_1_NEEDED:
2041 if (aprop != NULL && bprop != NULL)
2042 {
2043 number = aprop->u.number;
2044 aprop->u.number = number | bprop->u.number;
2045 updated = number != (unsigned int) aprop->u.number;
2046 }
2047 else
2048 {
2049 /* Return TRUE if APROP is NULL to indicate that BPROP should
2050 be added to ABFD. */
2051 updated = aprop == NULL;
2052 }
2053 break;
2054
2055 case GNU_PROPERTY_X86_FEATURE_1_AND:
2056 /* Only one of APROP and BPROP can be NULL:
2057 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2058 2. If APROP is NULL, remove x86 feature.
2059 3. Otherwise, do nothing.
2060 */
2061 if (aprop != NULL && bprop != NULL)
2062 {
2063 features = 0;
2064 if (info->ibt)
2065 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2066 if (info->shstk)
2067 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2068 number = aprop->u.number;
2069 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2070 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2071 aprop->u.number = (number & bprop->u.number) | features;
2072 updated = number != (unsigned int) aprop->u.number;
2073 /* Remove the property if all feature bits are cleared. */
2074 if (aprop->u.number == 0)
2075 aprop->pr_kind = property_remove;
2076 }
2077 else
2078 {
2079 features = 0;
2080 if (info->ibt)
2081 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2082 if (info->shstk)
2083 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2084 if (features)
2085 {
2086 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2087 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2088 if (aprop != NULL)
2089 {
2090 number = aprop->u.number;
2091 aprop->u.number = number | features;
2092 updated = number != (unsigned int) aprop->u.number;
2093 }
2094 else
2095 {
2096 bprop->u.number |= features;
2097 updated = TRUE;
2098 }
2099 }
2100 else if (aprop != NULL)
2101 {
2102 aprop->pr_kind = property_remove;
2103 updated = TRUE;
2104 }
2105 }
2106 break;
2107
2108 default:
2109 /* Never should happen. */
2110 abort ();
2111 }
2112
2113 return updated;
2114 }
2115
2116 /* Set up x86 GNU properties. Return the first relocatable ELF input
2117 with GNU properties if found. Otherwise, return NULL. */
2118
2119 bfd *
2120 _bfd_x86_elf_link_setup_gnu_properties
2121 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2122 {
2123 bfd_boolean normal_target;
2124 bfd_boolean lazy_plt;
2125 asection *sec, *pltsec;
2126 bfd *dynobj;
2127 bfd_boolean use_ibt_plt;
2128 unsigned int plt_alignment, features;
2129 struct elf_x86_link_hash_table *htab;
2130 bfd *pbfd;
2131 bfd *ebfd = NULL;
2132 elf_property *prop;
2133 const struct elf_backend_data *bed;
2134 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2135 unsigned int got_align;
2136
2137 features = 0;
2138 if (info->ibt)
2139 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2140 if (info->shstk)
2141 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2142
2143 /* Find a normal input file with GNU property note. */
2144 for (pbfd = info->input_bfds;
2145 pbfd != NULL;
2146 pbfd = pbfd->link.next)
2147 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2148 && bfd_count_sections (pbfd) != 0)
2149 {
2150 ebfd = pbfd;
2151
2152 if (elf_properties (pbfd) != NULL)
2153 break;
2154 }
2155
2156 if (ebfd != NULL && features)
2157 {
2158 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
2159 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2160 prop = _bfd_elf_get_property (ebfd,
2161 GNU_PROPERTY_X86_FEATURE_1_AND,
2162 4);
2163 prop->u.number |= features;
2164 prop->pr_kind = property_number;
2165
2166 /* Create the GNU property note section if needed. */
2167 if (pbfd == NULL)
2168 {
2169 sec = bfd_make_section_with_flags (ebfd,
2170 NOTE_GNU_PROPERTY_SECTION_NAME,
2171 (SEC_ALLOC
2172 | SEC_LOAD
2173 | SEC_IN_MEMORY
2174 | SEC_READONLY
2175 | SEC_HAS_CONTENTS
2176 | SEC_DATA));
2177 if (sec == NULL)
2178 info->callbacks->einfo (_("%F: failed to create GNU property section\n"));
2179
2180 if (!bfd_set_section_alignment (ebfd, sec, class_align))
2181 {
2182 error_alignment:
2183 info->callbacks->einfo (_("%F%A: failed to align section\n"),
2184 sec);
2185 }
2186
2187 elf_section_type (sec) = SHT_NOTE;
2188 }
2189 }
2190
2191 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2192
2193 bed = get_elf_backend_data (info->output_bfd);
2194
2195 htab = elf_x86_hash_table (info, bed->target_id);
2196 if (htab == NULL)
2197 return pbfd;
2198
2199 htab->is_vxworks = init_table->is_vxworks;
2200 htab->r_info = init_table->r_info;
2201 htab->r_sym = init_table->r_sym;
2202
2203 if (bfd_link_relocatable (info))
2204 return pbfd;
2205
2206 use_ibt_plt = info->ibtplt || info->ibt;
2207 if (!use_ibt_plt && pbfd != NULL)
2208 {
2209 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2210 elf_property_list *p;
2211
2212 /* The property list is sorted in order of type. */
2213 for (p = elf_properties (pbfd); p; p = p->next)
2214 {
2215 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2216 {
2217 use_ibt_plt = !!(p->property.u.number
2218 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2219 break;
2220 }
2221 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2222 break;
2223 }
2224 }
2225
2226 dynobj = htab->elf.dynobj;
2227
2228 /* Set htab->elf.dynobj here so that there is no need to check and
2229 set it in check_relocs. */
2230 if (dynobj == NULL)
2231 {
2232 if (pbfd != NULL)
2233 {
2234 htab->elf.dynobj = pbfd;
2235 dynobj = pbfd;
2236 }
2237 else
2238 {
2239 bfd *abfd;
2240
2241 /* Find a normal input file to hold linker created
2242 sections. */
2243 for (abfd = info->input_bfds;
2244 abfd != NULL;
2245 abfd = abfd->link.next)
2246 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2247 && (abfd->flags
2248 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0)
2249 {
2250 htab->elf.dynobj = abfd;
2251 dynobj = abfd;
2252 break;
2253 }
2254 }
2255 }
2256
2257 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2258 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2259 canonical function address. */
2260 htab->plt.has_plt0 = 1;
2261 normal_target = init_table->normal_target;
2262
2263 if (normal_target)
2264 {
2265 if (use_ibt_plt)
2266 {
2267 htab->lazy_plt = init_table->lazy_ibt_plt;
2268 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2269 }
2270 else
2271 {
2272 htab->lazy_plt = init_table->lazy_plt;
2273 htab->non_lazy_plt = init_table->non_lazy_plt;
2274 }
2275 }
2276 else
2277 {
2278 htab->lazy_plt = init_table->lazy_plt;
2279 htab->non_lazy_plt = NULL;
2280 }
2281
2282 pltsec = htab->elf.splt;
2283
2284 /* If the non-lazy PLT is available, use it for all PLT entries if
2285 there are no PLT0 or no .plt section. */
2286 if (htab->non_lazy_plt != NULL
2287 && (!htab->plt.has_plt0 || pltsec == NULL))
2288 {
2289 lazy_plt = FALSE;
2290 if (bfd_link_pic (info))
2291 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2292 else
2293 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2294 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2295 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2296 htab->plt.plt_got_insn_size
2297 = htab->non_lazy_plt->plt_got_insn_size;
2298 htab->plt.eh_frame_plt_size
2299 = htab->non_lazy_plt->eh_frame_plt_size;
2300 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2301 }
2302 else
2303 {
2304 lazy_plt = TRUE;
2305 if (bfd_link_pic (info))
2306 {
2307 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2308 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2309 }
2310 else
2311 {
2312 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2313 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2314 }
2315 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2316 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2317 htab->plt.plt_got_insn_size
2318 = htab->lazy_plt->plt_got_insn_size;
2319 htab->plt.eh_frame_plt_size
2320 = htab->lazy_plt->eh_frame_plt_size;
2321 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2322 }
2323
2324 /* Return if there are no normal input files. */
2325 if (dynobj == NULL)
2326 return pbfd;
2327
2328 if (htab->is_vxworks
2329 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2330 &htab->srelplt2))
2331 {
2332 info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n"));
2333 return pbfd;
2334 }
2335
2336 /* Since create_dynamic_sections isn't always called, but GOT
2337 relocations need GOT relocations, create them here so that we
2338 don't need to do it in check_relocs. */
2339 if (htab->elf.sgot == NULL
2340 && !_bfd_elf_create_got_section (dynobj, info))
2341 info->callbacks->einfo (_("%F: failed to create GOT sections\n"));
2342
2343 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2344
2345 /* Align .got and .got.plt sections to their entry size. Do it here
2346 instead of in create_dynamic_sections so that they are always
2347 properly aligned even if create_dynamic_sections isn't called. */
2348 sec = htab->elf.sgot;
2349 if (!bfd_set_section_alignment (dynobj, sec, got_align))
2350 goto error_alignment;
2351
2352 sec = htab->elf.sgotplt;
2353 if (!bfd_set_section_alignment (dynobj, sec, got_align))
2354 goto error_alignment;
2355
2356 /* Create the ifunc sections here so that check_relocs can be
2357 simplified. */
2358 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2359 info->callbacks->einfo (_("%F: failed to create ifunc sections\n"));
2360
2361 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2362
2363 if (pltsec != NULL)
2364 {
2365 /* Whe creating executable, set the contents of the .interp
2366 section to the interpreter. */
2367 if (bfd_link_executable (info) && !info->nointerp)
2368 {
2369 asection *s = bfd_get_linker_section (dynobj, ".interp");
2370 if (s == NULL)
2371 abort ();
2372 s->size = htab->dynamic_interpreter_size;
2373 s->contents = (unsigned char *) htab->dynamic_interpreter;
2374 htab->interp = s;
2375 }
2376
2377 /* Don't change PLT section alignment for NaCl since it uses
2378 64-byte PLT entry and sets PLT section alignment to 32
2379 bytes. Don't create additional PLT sections for NaCl. */
2380 if (normal_target)
2381 {
2382 flagword pltflags = (bed->dynamic_sec_flags
2383 | SEC_ALLOC
2384 | SEC_CODE
2385 | SEC_LOAD
2386 | SEC_READONLY);
2387 unsigned int non_lazy_plt_alignment
2388 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2389
2390 sec = pltsec;
2391 if (!bfd_set_section_alignment (sec->owner, sec,
2392 plt_alignment))
2393 goto error_alignment;
2394
2395 /* Create the GOT procedure linkage table. */
2396 sec = bfd_make_section_anyway_with_flags (dynobj,
2397 ".plt.got",
2398 pltflags);
2399 if (sec == NULL)
2400 info->callbacks->einfo (_("%F: failed to create GOT PLT section\n"));
2401
2402 if (!bfd_set_section_alignment (dynobj, sec,
2403 non_lazy_plt_alignment))
2404 goto error_alignment;
2405
2406 htab->plt_got = sec;
2407
2408 if (lazy_plt)
2409 {
2410 sec = NULL;
2411
2412 if (use_ibt_plt)
2413 {
2414 /* Create the second PLT for Intel IBT support. IBT
2415 PLT is supported only for non-NaCl target and is
2416 is needed only for lazy binding. */
2417 sec = bfd_make_section_anyway_with_flags (dynobj,
2418 ".plt.sec",
2419 pltflags);
2420 if (sec == NULL)
2421 info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n"));
2422
2423 if (!bfd_set_section_alignment (dynobj, sec,
2424 plt_alignment))
2425 goto error_alignment;
2426 }
2427 else if (info->bndplt && ABI_64_P (dynobj))
2428 {
2429 /* Create the second PLT for Intel MPX support. MPX
2430 PLT is supported only for non-NaCl target in 64-bit
2431 mode and is needed only for lazy binding. */
2432 sec = bfd_make_section_anyway_with_flags (dynobj,
2433 ".plt.sec",
2434 pltflags);
2435 if (sec == NULL)
2436 info->callbacks->einfo (_("%F: failed to create BND PLT section\n"));
2437
2438 if (!bfd_set_section_alignment (dynobj, sec,
2439 non_lazy_plt_alignment))
2440 goto error_alignment;
2441 }
2442
2443 htab->plt_second = sec;
2444 }
2445 }
2446
2447 if (!info->no_ld_generated_unwind_info)
2448 {
2449 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
2450 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
2451 | SEC_LINKER_CREATED);
2452
2453 sec = bfd_make_section_anyway_with_flags (dynobj,
2454 ".eh_frame",
2455 flags);
2456 if (sec == NULL)
2457 info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n"));
2458
2459 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2460 goto error_alignment;
2461
2462 htab->plt_eh_frame = sec;
2463
2464 if (htab->plt_got != NULL)
2465 {
2466 sec = bfd_make_section_anyway_with_flags (dynobj,
2467 ".eh_frame",
2468 flags);
2469 if (sec == NULL)
2470 info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n"));
2471
2472 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2473 goto error_alignment;
2474
2475 htab->plt_got_eh_frame = sec;
2476 }
2477
2478 if (htab->plt_second != NULL)
2479 {
2480 sec = bfd_make_section_anyway_with_flags (dynobj,
2481 ".eh_frame",
2482 flags);
2483 if (sec == NULL)
2484 info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n"));
2485
2486 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2487 goto error_alignment;
2488
2489 htab->plt_second_eh_frame = sec;
2490 }
2491 }
2492 }
2493
2494 if (normal_target)
2495 {
2496 /* The .iplt section is used for IFUNC symbols in static
2497 executables. */
2498 sec = htab->elf.iplt;
2499 if (sec != NULL
2500 && !bfd_set_section_alignment (sec->owner, sec,
2501 plt_alignment))
2502 goto error_alignment;
2503 }
2504
2505 return pbfd;
2506 }
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