Reformat elf_x86_allocate_dynrelocs
[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, void *inf)
87 {
88 struct bfd_link_info *info;
89 struct elf_x86_link_hash_table *htab;
90 struct elf_x86_link_hash_entry *eh;
91 struct elf_dyn_relocs *p;
92 unsigned int plt_entry_size;
93 bfd_boolean resolved_to_zero;
94 const struct elf_backend_data *bed;
95
96 if (h->root.type == bfd_link_hash_indirect)
97 return TRUE;
98
99 eh = (struct elf_x86_link_hash_entry *) h;
100
101 info = (struct bfd_link_info *) inf;
102 bed = get_elf_backend_data (info->output_bfd);
103 htab = elf_x86_hash_table (info, bed->target_id);
104 if (htab == NULL)
105 return FALSE;
106
107 plt_entry_size = htab->plt.plt_entry_size;
108
109 resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
110
111 /* Clear the reference count of function pointer relocations if
112 symbol isn't a normal function. */
113 if (h->type != STT_FUNC)
114 eh->func_pointer_refcount = 0;
115
116 /* We can't use the GOT PLT if pointer equality is needed since
117 finish_dynamic_symbol won't clear symbol value and the dynamic
118 linker won't update the GOT slot. We will get into an infinite
119 loop at run-time. */
120 if (htab->plt_got != NULL
121 && h->type != STT_GNU_IFUNC
122 && !h->pointer_equality_needed
123 && h->plt.refcount > 0
124 && h->got.refcount > 0)
125 {
126 /* Don't use the regular PLT if there are both GOT and GOTPLT
127 reloctions. */
128 h->plt.offset = (bfd_vma) -1;
129
130 /* Use the GOT PLT. */
131 eh->plt_got.refcount = 1;
132 }
133
134 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
135 here if it is defined and referenced in a non-shared object. */
136 if (h->type == STT_GNU_IFUNC
137 && h->def_regular)
138 {
139 if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs,
140 &htab->readonly_dynrelocs_against_ifunc,
141 plt_entry_size,
142 (htab->plt.has_plt0
143 * plt_entry_size),
144 htab->got_entry_size,
145 TRUE))
146 {
147 asection *s = htab->plt_second;
148 if (h->plt.offset != (bfd_vma) -1 && s != NULL)
149 {
150 /* Use the second PLT section if it is created. */
151 eh->plt_second.offset = s->size;
152
153 /* Make room for this entry in the second PLT section. */
154 s->size += htab->non_lazy_plt->plt_entry_size;
155 }
156
157 return TRUE;
158 }
159 else
160 return FALSE;
161 }
162 /* Don't create the PLT entry if there are only function pointer
163 relocations which can be resolved at run-time. */
164 else if (htab->elf.dynamic_sections_created
165 && (h->plt.refcount > eh->func_pointer_refcount
166 || eh->plt_got.refcount > 0))
167 {
168 bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
169
170 /* Clear the reference count of function pointer relocations
171 if PLT is used. */
172 eh->func_pointer_refcount = 0;
173
174 /* Make sure this symbol is output as a dynamic symbol.
175 Undefined weak syms won't yet be marked as dynamic. */
176 if (h->dynindx == -1
177 && !h->forced_local
178 && !resolved_to_zero
179 && h->root.type == bfd_link_hash_undefweak)
180 {
181 if (! bfd_elf_link_record_dynamic_symbol (info, h))
182 return FALSE;
183 }
184
185 if (bfd_link_pic (info)
186 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
187 {
188 asection *s = htab->elf.splt;
189 asection *second_s = htab->plt_second;
190 asection *got_s = htab->plt_got;
191
192 /* If this is the first .plt entry, make room for the special
193 first entry. The .plt section is used by prelink to undo
194 prelinking for dynamic relocations. */
195 if (s->size == 0)
196 s->size = htab->plt.has_plt0 * plt_entry_size;
197
198 if (use_plt_got)
199 eh->plt_got.offset = got_s->size;
200 else
201 {
202 h->plt.offset = s->size;
203 if (second_s)
204 eh->plt_second.offset = second_s->size;
205 }
206
207 /* If this symbol is not defined in a regular file, and we are
208 not generating a shared library, then set the symbol to this
209 location in the .plt. This is required to make function
210 pointers compare as equal between the normal executable and
211 the shared library. */
212 if (! bfd_link_pic (info)
213 && !h->def_regular)
214 {
215 if (use_plt_got)
216 {
217 /* We need to make a call to the entry of the GOT PLT
218 instead of regular PLT entry. */
219 h->root.u.def.section = got_s;
220 h->root.u.def.value = eh->plt_got.offset;
221 }
222 else
223 {
224 if (second_s)
225 {
226 /* We need to make a call to the entry of the
227 second PLT instead of regular PLT entry. */
228 h->root.u.def.section = second_s;
229 h->root.u.def.value = eh->plt_second.offset;
230 }
231 else
232 {
233 h->root.u.def.section = s;
234 h->root.u.def.value = h->plt.offset;
235 }
236 }
237 }
238
239 /* Make room for this entry. */
240 if (use_plt_got)
241 got_s->size += htab->non_lazy_plt->plt_entry_size;
242 else
243 {
244 s->size += plt_entry_size;
245 if (second_s)
246 second_s->size += htab->non_lazy_plt->plt_entry_size;
247
248 /* We also need to make an entry in the .got.plt section,
249 which will be placed in the .got section by the linker
250 script. */
251 htab->elf.sgotplt->size += htab->got_entry_size;
252
253 /* There should be no PLT relocation against resolved
254 undefined weak symbol in executable. */
255 if (!resolved_to_zero)
256 {
257 /* We also need to make an entry in the .rel.plt
258 section. */
259 htab->elf.srelplt->size += htab->sizeof_reloc;
260 htab->elf.srelplt->reloc_count++;
261 }
262 }
263
264 if (htab->is_vxworks && !bfd_link_pic (info))
265 {
266 /* VxWorks has a second set of relocations for each PLT entry
267 in executables. They go in a separate relocation section,
268 which is processed by the kernel loader. */
269
270 /* There are two relocations for the initial PLT entry: an
271 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
272 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
273
274 asection *srelplt2 = htab->srelplt2;
275 if (h->plt.offset == plt_entry_size)
276 srelplt2->size += (htab->sizeof_reloc * 2);
277
278 /* There are two extra relocations for each subsequent PLT entry:
279 an R_386_32 relocation for the GOT entry, and an R_386_32
280 relocation for the PLT entry. */
281
282 srelplt2->size += (htab->sizeof_reloc * 2);
283 }
284 }
285 else
286 {
287 eh->plt_got.offset = (bfd_vma) -1;
288 h->plt.offset = (bfd_vma) -1;
289 h->needs_plt = 0;
290 }
291 }
292 else
293 {
294 eh->plt_got.offset = (bfd_vma) -1;
295 h->plt.offset = (bfd_vma) -1;
296 h->needs_plt = 0;
297 }
298
299 eh->tlsdesc_got = (bfd_vma) -1;
300
301 /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the
302 binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For
303 x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary,
304 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
305 if (h->got.refcount > 0
306 && bfd_link_executable (info)
307 && h->dynindx == -1
308 && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
309 h->got.offset = (bfd_vma) -1;
310 else if (h->got.refcount > 0)
311 {
312 asection *s;
313 bfd_boolean dyn;
314 int tls_type = elf_x86_hash_entry (h)->tls_type;
315
316 /* Make sure this symbol is output as a dynamic symbol.
317 Undefined weak syms won't yet be marked as dynamic. */
318 if (h->dynindx == -1
319 && !h->forced_local
320 && !resolved_to_zero
321 && h->root.type == bfd_link_hash_undefweak)
322 {
323 if (! bfd_elf_link_record_dynamic_symbol (info, h))
324 return FALSE;
325 }
326
327 s = htab->elf.sgot;
328 if (GOT_TLS_GDESC_P (tls_type))
329 {
330 eh->tlsdesc_got = htab->elf.sgotplt->size
331 - elf_x86_compute_jump_table_size (htab);
332 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
333 h->got.offset = (bfd_vma) -2;
334 }
335 if (! GOT_TLS_GDESC_P (tls_type)
336 || GOT_TLS_GD_P (tls_type))
337 {
338 h->got.offset = s->size;
339 s->size += htab->got_entry_size;
340 /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT
341 slots. */
342 if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
343 s->size += htab->got_entry_size;
344 }
345 dyn = htab->elf.dynamic_sections_created;
346 /* R_386_TLS_IE_32 needs one dynamic relocation,
347 R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
348 (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
349 need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local
350 symbol and two if global. No dynamic relocation against
351 resolved undefined weak symbol in executable. */
352 if (tls_type == GOT_TLS_IE_BOTH)
353 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
354 else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
355 || (tls_type & GOT_TLS_IE))
356 htab->elf.srelgot->size += htab->sizeof_reloc;
357 else if (GOT_TLS_GD_P (tls_type))
358 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
359 else if (! GOT_TLS_GDESC_P (tls_type)
360 && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
361 && !resolved_to_zero)
362 || h->root.type != bfd_link_hash_undefweak)
363 && (bfd_link_pic (info)
364 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
365 htab->elf.srelgot->size += htab->sizeof_reloc;
366 if (GOT_TLS_GDESC_P (tls_type))
367 {
368 htab->elf.srelplt->size += htab->sizeof_reloc;
369 if (bed->target_id == X86_64_ELF_DATA)
370 htab->tlsdesc_plt = (bfd_vma) -1;
371 }
372 }
373 else
374 h->got.offset = (bfd_vma) -1;
375
376 if (eh->dyn_relocs == NULL)
377 return TRUE;
378
379 /* In the shared -Bsymbolic case, discard space allocated for
380 dynamic pc-relative relocs against symbols which turn out to be
381 defined in regular objects. For the normal shared case, discard
382 space for pc-relative relocs that have become local due to symbol
383 visibility changes. */
384
385 if (bfd_link_pic (info))
386 {
387 /* Relocs that use pc_count are those that appear on a call
388 insn, or certain REL relocs that can generated via assembly.
389 We want calls to protected symbols to resolve directly to the
390 function rather than going via the plt. If people want
391 function pointer comparisons to work as expected then they
392 should avoid writing weird assembly. */
393 if (SYMBOL_CALLS_LOCAL (info, h))
394 {
395 struct elf_dyn_relocs **pp;
396
397 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
398 {
399 p->count -= p->pc_count;
400 p->pc_count = 0;
401 if (p->count == 0)
402 *pp = p->next;
403 else
404 pp = &p->next;
405 }
406 }
407
408 if (htab->is_vxworks)
409 {
410 struct elf_dyn_relocs **pp;
411 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
412 {
413 if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
414 *pp = p->next;
415 else
416 pp = &p->next;
417 }
418 }
419
420 /* Also discard relocs on undefined weak syms with non-default
421 visibility or in PIE. */
422 if (eh->dyn_relocs != NULL)
423 {
424 if (h->root.type == bfd_link_hash_undefweak)
425 {
426 /* Undefined weak symbol is never bound locally in shared
427 library. */
428 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
429 || resolved_to_zero)
430 {
431 if (bed->target_id == I386_ELF_DATA
432 && h->non_got_ref)
433 {
434 /* Keep dynamic non-GOT/non-PLT relocation so
435 that we can branch to 0 without PLT. */
436 struct elf_dyn_relocs **pp;
437
438 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
439 if (p->pc_count == 0)
440 *pp = p->next;
441 else
442 {
443 /* Remove non-R_386_PC32 relocation. */
444 p->count = p->pc_count;
445 pp = &p->next;
446 }
447
448 /* Make sure undefined weak symbols are output
449 as dynamic symbols in PIEs for dynamic non-GOT
450 non-PLT reloations. */
451 if (eh->dyn_relocs != NULL
452 && !bfd_elf_link_record_dynamic_symbol (info, h))
453 return FALSE;
454 }
455 else
456 eh->dyn_relocs = NULL;
457 }
458 else if (h->dynindx == -1
459 && !h->forced_local
460 && !bfd_elf_link_record_dynamic_symbol (info, h))
461 return FALSE;
462 }
463 else if (bfd_link_executable (info)
464 && (h->needs_copy || eh->needs_copy)
465 && h->def_dynamic
466 && !h->def_regular)
467 {
468 /* NB: needs_copy is set only for x86-64. For PIE,
469 discard space for pc-relative relocs against symbols
470 which turn out to need copy relocs. */
471 struct elf_dyn_relocs **pp;
472
473 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
474 {
475 if (p->pc_count != 0)
476 *pp = p->next;
477 else
478 pp = &p->next;
479 }
480 }
481 }
482 }
483 else if (ELIMINATE_COPY_RELOCS)
484 {
485 /* For the non-shared case, discard space for relocs against
486 symbols which turn out to need copy relocs or are not
487 dynamic. Keep dynamic relocations for run-time function
488 pointer initialization. */
489
490 if ((!h->non_got_ref
491 || eh->func_pointer_refcount > 0
492 || (h->root.type == bfd_link_hash_undefweak
493 && !resolved_to_zero))
494 && ((h->def_dynamic
495 && !h->def_regular)
496 || (htab->elf.dynamic_sections_created
497 && (h->root.type == bfd_link_hash_undefweak
498 || h->root.type == bfd_link_hash_undefined))))
499 {
500 /* Make sure this symbol is output as a dynamic symbol.
501 Undefined weak syms won't yet be marked as dynamic. */
502 if (h->dynindx == -1
503 && !h->forced_local
504 && !resolved_to_zero
505 && h->root.type == bfd_link_hash_undefweak
506 && ! bfd_elf_link_record_dynamic_symbol (info, h))
507 return FALSE;
508
509 /* If that succeeded, we know we'll be keeping all the
510 relocs. */
511 if (h->dynindx != -1)
512 goto keep;
513 }
514
515 eh->dyn_relocs = NULL;
516 eh->func_pointer_refcount = 0;
517
518 keep: ;
519 }
520
521 /* Finally, allocate space. */
522 for (p = eh->dyn_relocs; p != NULL; p = p->next)
523 {
524 asection *sreloc;
525
526 sreloc = elf_section_data (p->sec)->sreloc;
527
528 BFD_ASSERT (sreloc != NULL);
529 sreloc->size += p->count * htab->sizeof_reloc;
530 }
531
532 return TRUE;
533 }
534
535 /* Find any dynamic relocs that apply to read-only sections. */
536
537 bfd_boolean
538 _bfd_x86_elf_readonly_dynrelocs (struct elf_link_hash_entry *h,
539 void *inf)
540 {
541 struct elf_x86_link_hash_entry *eh;
542 struct elf_dyn_relocs *p;
543
544 /* Skip local IFUNC symbols. */
545 if (h->forced_local && h->type == STT_GNU_IFUNC)
546 return TRUE;
547
548 eh = (struct elf_x86_link_hash_entry *) h;
549 for (p = eh->dyn_relocs; p != NULL; p = p->next)
550 {
551 asection *s = p->sec->output_section;
552
553 if (s != NULL && (s->flags & SEC_READONLY) != 0)
554 {
555 struct bfd_link_info *info = (struct bfd_link_info *) inf;
556
557 info->flags |= DF_TEXTREL;
558
559 if ((info->warn_shared_textrel && bfd_link_pic (info))
560 || info->error_textrel)
561 /* xgettext:c-format */
562 info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"),
563 p->sec->owner, h->root.root.string,
564 p->sec);
565
566 /* Not an error, just cut short the traversal. */
567 return FALSE;
568 }
569 }
570 return TRUE;
571 }
572
573 /* Allocate space in .plt, .got and associated reloc sections for
574 local dynamic relocs. */
575
576 static bfd_boolean
577 elf_x86_allocate_local_dynreloc (void **slot, void *inf)
578 {
579 struct elf_link_hash_entry *h
580 = (struct elf_link_hash_entry *) *slot;
581
582 if (h->type != STT_GNU_IFUNC
583 || !h->def_regular
584 || !h->ref_regular
585 || !h->forced_local
586 || h->root.type != bfd_link_hash_defined)
587 abort ();
588
589 return elf_x86_allocate_dynrelocs (h, inf);
590 }
591
592 /* Find and/or create a hash entry for local symbol. */
593
594 struct elf_link_hash_entry *
595 _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab,
596 bfd *abfd, const Elf_Internal_Rela *rel,
597 bfd_boolean create)
598 {
599 struct elf_x86_link_hash_entry e, *ret;
600 asection *sec = abfd->sections;
601 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id,
602 htab->r_sym (rel->r_info));
603 void **slot;
604
605 e.elf.indx = sec->id;
606 e.elf.dynstr_index = htab->r_sym (rel->r_info);
607 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h,
608 create ? INSERT : NO_INSERT);
609
610 if (!slot)
611 return NULL;
612
613 if (*slot)
614 {
615 ret = (struct elf_x86_link_hash_entry *) *slot;
616 return &ret->elf;
617 }
618
619 ret = (struct elf_x86_link_hash_entry *)
620 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory,
621 sizeof (struct elf_x86_link_hash_entry));
622 if (ret)
623 {
624 memset (ret, 0, sizeof (*ret));
625 ret->elf.indx = sec->id;
626 ret->elf.dynstr_index = htab->r_sym (rel->r_info);
627 ret->elf.dynindx = -1;
628 ret->plt_got.offset = (bfd_vma) -1;
629 *slot = ret;
630 }
631 return &ret->elf;
632 }
633
634 /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN
635 SYNC WITH _bfd_elf_link_hash_newfunc. */
636
637 struct bfd_hash_entry *
638 _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry,
639 struct bfd_hash_table *table,
640 const char *string)
641 {
642 /* Allocate the structure if it has not already been allocated by a
643 subclass. */
644 if (entry == NULL)
645 {
646 entry = (struct bfd_hash_entry *)
647 bfd_hash_allocate (table,
648 sizeof (struct elf_x86_link_hash_entry));
649 if (entry == NULL)
650 return entry;
651 }
652
653 /* Call the allocation method of the superclass. */
654 entry = _bfd_link_hash_newfunc (entry, table, string);
655 if (entry != NULL)
656 {
657 struct elf_x86_link_hash_entry *eh
658 = (struct elf_x86_link_hash_entry *) entry;
659 struct elf_link_hash_table *htab
660 = (struct elf_link_hash_table *) table;
661
662 memset (&eh->elf.size, 0,
663 (sizeof (struct elf_x86_link_hash_entry)
664 - offsetof (struct elf_link_hash_entry, size)));
665 /* Set local fields. */
666 eh->elf.indx = -1;
667 eh->elf.dynindx = -1;
668 eh->elf.got = htab->init_got_refcount;
669 eh->elf.plt = htab->init_plt_refcount;
670 /* Assume that we have been called by a non-ELF symbol reader.
671 This flag is then reset by the code which reads an ELF input
672 file. This ensures that a symbol created by a non-ELF symbol
673 reader will have the flag set correctly. */
674 eh->elf.non_elf = 1;
675 eh->plt_second.offset = (bfd_vma) -1;
676 eh->plt_got.offset = (bfd_vma) -1;
677 eh->tlsdesc_got = (bfd_vma) -1;
678 eh->zero_undefweak = 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->zero_undefweak |= eind->zero_undefweak;
1411
1412 if (ELIMINATE_COPY_RELOCS
1413 && ind->root.type != bfd_link_hash_indirect
1414 && dir->dynamic_adjusted)
1415 {
1416 /* If called to transfer flags for a weakdef during processing
1417 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
1418 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
1419 if (dir->versioned != versioned_hidden)
1420 dir->ref_dynamic |= ind->ref_dynamic;
1421 dir->ref_regular |= ind->ref_regular;
1422 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
1423 dir->needs_plt |= ind->needs_plt;
1424 dir->pointer_equality_needed |= ind->pointer_equality_needed;
1425 }
1426 else
1427 {
1428 if (eind->func_pointer_refcount > 0)
1429 {
1430 edir->func_pointer_refcount += eind->func_pointer_refcount;
1431 eind->func_pointer_refcount = 0;
1432 }
1433
1434 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
1435 }
1436 }
1437
1438 /* Remove undefined weak symbol from the dynamic symbol table if it
1439 is resolved to 0. */
1440
1441 bfd_boolean
1442 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
1443 struct elf_link_hash_entry *h)
1444 {
1445 if (h->dynindx != -1
1446 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h)))
1447 {
1448 h->dynindx = -1;
1449 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
1450 h->dynstr_index);
1451 }
1452 return TRUE;
1453 }
1454
1455 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1456
1457 bfd_boolean
1458 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1459 {
1460 if (h->plt.offset != (bfd_vma) -1
1461 && !h->def_regular
1462 && !h->pointer_equality_needed)
1463 return FALSE;
1464
1465 return _bfd_elf_hash_symbol (h);
1466 }
1467
1468 /* Adjust a symbol defined by a dynamic object and referenced by a
1469 regular object. The current definition is in some section of the
1470 dynamic object, but we're not including those sections. We have to
1471 change the definition to something the rest of the link can
1472 understand. */
1473
1474 bfd_boolean
1475 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1476 struct elf_link_hash_entry *h)
1477 {
1478 struct elf_x86_link_hash_table *htab;
1479 asection *s, *srel;
1480 struct elf_x86_link_hash_entry *eh;
1481 struct elf_dyn_relocs *p;
1482 const struct elf_backend_data *bed
1483 = get_elf_backend_data (info->output_bfd);
1484
1485 /* STT_GNU_IFUNC symbol must go through PLT. */
1486 if (h->type == STT_GNU_IFUNC)
1487 {
1488 /* All local STT_GNU_IFUNC references must be treate as local
1489 calls via local PLT. */
1490 if (h->ref_regular
1491 && SYMBOL_CALLS_LOCAL (info, h))
1492 {
1493 bfd_size_type pc_count = 0, count = 0;
1494 struct elf_dyn_relocs **pp;
1495
1496 eh = (struct elf_x86_link_hash_entry *) h;
1497 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1498 {
1499 pc_count += p->pc_count;
1500 p->count -= p->pc_count;
1501 p->pc_count = 0;
1502 count += p->count;
1503 if (p->count == 0)
1504 *pp = p->next;
1505 else
1506 pp = &p->next;
1507 }
1508
1509 if (pc_count || count)
1510 {
1511 h->non_got_ref = 1;
1512 if (pc_count)
1513 {
1514 /* Increment PLT reference count only for PC-relative
1515 references. */
1516 h->needs_plt = 1;
1517 if (h->plt.refcount <= 0)
1518 h->plt.refcount = 1;
1519 else
1520 h->plt.refcount += 1;
1521 }
1522 }
1523 }
1524
1525 if (h->plt.refcount <= 0)
1526 {
1527 h->plt.offset = (bfd_vma) -1;
1528 h->needs_plt = 0;
1529 }
1530 return TRUE;
1531 }
1532
1533 /* If this is a function, put it in the procedure linkage table. We
1534 will fill in the contents of the procedure linkage table later,
1535 when we know the address of the .got section. */
1536 if (h->type == STT_FUNC
1537 || h->needs_plt)
1538 {
1539 if (h->plt.refcount <= 0
1540 || SYMBOL_CALLS_LOCAL (info, h)
1541 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1542 && h->root.type == bfd_link_hash_undefweak))
1543 {
1544 /* This case can occur if we saw a PLT32 reloc in an input
1545 file, but the symbol was never referred to by a dynamic
1546 object, or if all references were garbage collected. In
1547 such a case, we don't actually need to build a procedure
1548 linkage table, and we can just do a PC32 reloc instead. */
1549 h->plt.offset = (bfd_vma) -1;
1550 h->needs_plt = 0;
1551 }
1552
1553 return TRUE;
1554 }
1555 else
1556 /* It's possible that we incorrectly decided a .plt reloc was needed
1557 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
1558 check_relocs. We can't decide accurately between function and
1559 non-function syms in check-relocs; Objects loaded later in
1560 the link may change h->type. So fix it now. */
1561 h->plt.offset = (bfd_vma) -1;
1562
1563 eh = (struct elf_x86_link_hash_entry *) h;
1564
1565 /* If this is a weak symbol, and there is a real definition, the
1566 processor independent code will have arranged for us to see the
1567 real definition first, and we can just use the same value. */
1568 if (h->u.weakdef != NULL)
1569 {
1570 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1571 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1572 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1573 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1574 if (ELIMINATE_COPY_RELOCS
1575 || info->nocopyreloc
1576 || SYMBOL_NO_COPYRELOC (info, eh))
1577 {
1578 /* NB: needs_copy is always 0 for i386. */
1579 h->non_got_ref = h->u.weakdef->non_got_ref;
1580 eh->needs_copy = h->u.weakdef->needs_copy;
1581 }
1582 return TRUE;
1583 }
1584
1585 /* This is a reference to a symbol defined by a dynamic object which
1586 is not a function. */
1587
1588 /* If we are creating a shared library, we must presume that the
1589 only references to the symbol are via the global offset table.
1590 For such cases we need not do anything here; the relocations will
1591 be handled correctly by relocate_section. */
1592 if (!bfd_link_executable (info))
1593 return TRUE;
1594
1595 /* If there are no references to this symbol that do not use the
1596 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
1597 reloc. NB: gotoff_ref is always 0 for x86-64. */
1598 if (!h->non_got_ref && !eh->gotoff_ref)
1599 return TRUE;
1600
1601 /* If -z nocopyreloc was given, we won't generate them either. */
1602 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
1603 {
1604 h->non_got_ref = 0;
1605 return TRUE;
1606 }
1607
1608 htab = elf_x86_hash_table (info, bed->target_id);
1609 if (htab == NULL)
1610 return FALSE;
1611
1612 /* If there aren't any dynamic relocs in read-only sections nor
1613 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
1614 avoid the copy reloc. This doesn't work on VxWorks, where we can
1615 not have dynamic relocations (other than copy and jump slot
1616 relocations) in an executable. */
1617 if (ELIMINATE_COPY_RELOCS
1618 && (bed->target_id == X86_64_ELF_DATA
1619 || (!eh->gotoff_ref
1620 && !htab->is_vxworks)))
1621 {
1622 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1623 {
1624 s = p->sec->output_section;
1625 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1626 break;
1627 }
1628
1629 /* If we didn't find any dynamic relocs in read-only sections,
1630 then we'll be keeping the dynamic relocs and avoiding the copy
1631 reloc. */
1632 if (p == NULL)
1633 {
1634 h->non_got_ref = 0;
1635 return TRUE;
1636 }
1637 }
1638
1639 /* We must allocate the symbol in our .dynbss section, which will
1640 become part of the .bss section of the executable. There will be
1641 an entry for this symbol in the .dynsym section. The dynamic
1642 object will contain position independent code, so all references
1643 from the dynamic object to this symbol will go through the global
1644 offset table. The dynamic linker will use the .dynsym entry to
1645 determine the address it must put in the global offset table, so
1646 both the dynamic object and the regular object will refer to the
1647 same memory location for the variable. */
1648
1649 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
1650 dynamic linker to copy the initial value out of the dynamic object
1651 and into the runtime process image. */
1652 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
1653 {
1654 s = htab->elf.sdynrelro;
1655 srel = htab->elf.sreldynrelro;
1656 }
1657 else
1658 {
1659 s = htab->elf.sdynbss;
1660 srel = htab->elf.srelbss;
1661 }
1662 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
1663 {
1664 srel->size += htab->sizeof_reloc;
1665 h->needs_copy = 1;
1666 }
1667
1668 return _bfd_elf_adjust_dynamic_copy (info, h, s);
1669 }
1670
1671 /* Return TRUE if a symbol is referenced locally. It is similar to
1672 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
1673 works in check_relocs. */
1674
1675 bfd_boolean
1676 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
1677 struct elf_link_hash_entry *h)
1678 {
1679 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1680 struct elf_x86_link_hash_table *htab
1681 = (struct elf_x86_link_hash_table *) info->hash;
1682
1683 if (eh->local_ref > 1)
1684 return TRUE;
1685
1686 if (eh->local_ref == 1)
1687 return FALSE;
1688
1689 /* Unversioned symbols defined in regular objects can be forced local
1690 by linker version script. A weak undefined symbol is forced local
1691 if
1692 1. It has non-default visibility. Or
1693 2. When building executable, there is no dynamic linker. Or
1694 3. or "-z nodynamic-undefined-weak" is used.
1695 */
1696 if (SYMBOL_REFERENCES_LOCAL (info, h)
1697 || (h->root.type == bfd_link_hash_undefweak
1698 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1699 || (bfd_link_executable (info)
1700 && htab->interp == NULL)
1701 || info->dynamic_undefined_weak == 0))
1702 || ((h->def_regular || ELF_COMMON_DEF_P (h))
1703 && h->versioned == unversioned
1704 && info->version_info != NULL
1705 && bfd_hide_sym_by_version (info->version_info,
1706 h->root.root.string)))
1707 {
1708 eh->local_ref = 2;
1709 return TRUE;
1710 }
1711
1712 eh->local_ref = 1;
1713 return FALSE;
1714 }
1715
1716 /* Return the section that should be marked against GC for a given
1717 relocation. */
1718
1719 asection *
1720 _bfd_x86_elf_gc_mark_hook (asection *sec,
1721 struct bfd_link_info *info,
1722 Elf_Internal_Rela *rel,
1723 struct elf_link_hash_entry *h,
1724 Elf_Internal_Sym *sym)
1725 {
1726 /* Compiler should optimize this out. */
1727 if (((unsigned int) R_X86_64_GNU_VTINHERIT
1728 != (unsigned int) R_386_GNU_VTINHERIT)
1729 || ((unsigned int) R_X86_64_GNU_VTENTRY
1730 != (unsigned int) R_386_GNU_VTENTRY))
1731 abort ();
1732
1733 if (h != NULL)
1734 switch (ELF32_R_TYPE (rel->r_info))
1735 {
1736 case R_X86_64_GNU_VTINHERIT:
1737 case R_X86_64_GNU_VTENTRY:
1738 return NULL;
1739 }
1740
1741 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
1742 }
1743
1744 static bfd_vma
1745 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
1746 bfd_vma off,
1747 bfd_vma offset ATTRIBUTE_UNUSED,
1748 bfd_vma got_addr)
1749 {
1750 return got_addr + off;
1751 }
1752
1753 static bfd_vma
1754 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
1755 bfd_vma off,
1756 bfd_vma offset,
1757 bfd_vma got_addr ATTRIBUTE_UNUSED)
1758 {
1759 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
1760 }
1761
1762 static bfd_boolean
1763 elf_i386_valid_plt_reloc_p (unsigned int type)
1764 {
1765 return (type == R_386_JUMP_SLOT
1766 || type == R_386_GLOB_DAT
1767 || type == R_386_IRELATIVE);
1768 }
1769
1770 static bfd_boolean
1771 elf_x86_64_valid_plt_reloc_p (unsigned int type)
1772 {
1773 return (type == R_X86_64_JUMP_SLOT
1774 || type == R_X86_64_GLOB_DAT
1775 || type == R_X86_64_IRELATIVE);
1776 }
1777
1778 long
1779 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
1780 long count,
1781 long relsize,
1782 bfd_vma got_addr,
1783 struct elf_x86_plt plts[],
1784 asymbol **dynsyms,
1785 asymbol **ret)
1786 {
1787 long size, i, n, len;
1788 int j;
1789 unsigned int plt_got_offset, plt_entry_size;
1790 asymbol *s;
1791 bfd_byte *plt_contents;
1792 long dynrelcount;
1793 arelent **dynrelbuf, *p;
1794 char *names;
1795 const struct elf_backend_data *bed;
1796 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
1797 bfd_vma);
1798 bfd_boolean (*valid_plt_reloc_p) (unsigned int);
1799
1800 if (count == 0)
1801 return -1;
1802
1803 dynrelbuf = (arelent **) bfd_malloc (relsize);
1804 if (dynrelbuf == NULL)
1805 return -1;
1806
1807 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
1808 dynsyms);
1809 if (dynrelcount <= 0)
1810 return -1;
1811
1812 /* Sort the relocs by address. */
1813 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
1814 _bfd_x86_elf_compare_relocs);
1815
1816 size = count * sizeof (asymbol);
1817
1818 /* Allocate space for @plt suffixes. */
1819 n = 0;
1820 for (i = 0; i < dynrelcount; i++)
1821 {
1822 p = dynrelbuf[i];
1823 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
1824 if (p->addend != 0)
1825 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
1826 }
1827
1828 s = *ret = (asymbol *) bfd_zmalloc (size);
1829 if (s == NULL)
1830 goto bad_return;
1831
1832 bed = get_elf_backend_data (abfd);
1833
1834 if (bed->target_id == X86_64_ELF_DATA)
1835 {
1836 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
1837 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
1838 }
1839 else
1840 {
1841 get_plt_got_vma = elf_i386_get_plt_got_vma;
1842 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
1843 if (got_addr)
1844 {
1845 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
1846 address. */
1847 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
1848 if (sec != NULL)
1849 got_addr = sec->vma;
1850 else
1851 {
1852 sec = bfd_get_section_by_name (abfd, ".got");
1853 if (sec != NULL)
1854 got_addr = sec->vma;
1855 }
1856
1857 if (got_addr == (bfd_vma) -1)
1858 goto bad_return;
1859 }
1860 }
1861
1862 /* Check for each PLT section. */
1863 names = (char *) (s + count);
1864 size = 0;
1865 n = 0;
1866 for (j = 0; plts[j].name != NULL; j++)
1867 if ((plt_contents = plts[j].contents) != NULL)
1868 {
1869 long k;
1870 bfd_vma offset;
1871 asection *plt;
1872 struct elf_x86_plt *plt_p = &plts[j];
1873
1874 plt_got_offset = plt_p->plt_got_offset;
1875 plt_entry_size = plt_p->plt_entry_size;
1876
1877 plt = plt_p->sec;
1878
1879 if ((plt_p->type & plt_lazy))
1880 {
1881 /* Skip PLT0 in lazy PLT. */
1882 k = 1;
1883 offset = plt_entry_size;
1884 }
1885 else
1886 {
1887 k = 0;
1888 offset = 0;
1889 }
1890
1891 /* Check each PLT entry against dynamic relocations. */
1892 for (; k < plt_p->count; k++)
1893 {
1894 int off;
1895 bfd_vma got_vma;
1896 long min, max, mid;
1897
1898 /* Get the GOT offset for i386 or the PC-relative offset
1899 for x86-64, a signed 32-bit integer. */
1900 off = H_GET_32 (abfd, (plt_contents + offset
1901 + plt_got_offset));
1902 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
1903
1904 /* Binary search. */
1905 p = dynrelbuf[0];
1906 min = 0;
1907 max = dynrelcount;
1908 while ((min + 1) < max)
1909 {
1910 arelent *r;
1911
1912 mid = (min + max) / 2;
1913 r = dynrelbuf[mid];
1914 if (got_vma > r->address)
1915 min = mid;
1916 else if (got_vma < r->address)
1917 max = mid;
1918 else
1919 {
1920 p = r;
1921 break;
1922 }
1923 }
1924
1925 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
1926 if (got_vma == p->address
1927 && p->howto != NULL
1928 && valid_plt_reloc_p (p->howto->type))
1929 {
1930 *s = **p->sym_ptr_ptr;
1931 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
1932 set. Since we are defining a symbol, ensure one
1933 of them is set. */
1934 if ((s->flags & BSF_LOCAL) == 0)
1935 s->flags |= BSF_GLOBAL;
1936 s->flags |= BSF_SYNTHETIC;
1937 /* This is no longer a section symbol. */
1938 s->flags &= ~BSF_SECTION_SYM;
1939 s->section = plt;
1940 s->the_bfd = plt->owner;
1941 s->value = offset;
1942 s->udata.p = NULL;
1943 s->name = names;
1944 len = strlen ((*p->sym_ptr_ptr)->name);
1945 memcpy (names, (*p->sym_ptr_ptr)->name, len);
1946 names += len;
1947 if (p->addend != 0)
1948 {
1949 char buf[30], *a;
1950
1951 memcpy (names, "+0x", sizeof ("+0x") - 1);
1952 names += sizeof ("+0x") - 1;
1953 bfd_sprintf_vma (abfd, buf, p->addend);
1954 for (a = buf; *a == '0'; ++a)
1955 ;
1956 size = strlen (a);
1957 memcpy (names, a, size);
1958 names += size;
1959 }
1960 memcpy (names, "@plt", sizeof ("@plt"));
1961 names += sizeof ("@plt");
1962 n++;
1963 s++;
1964 /* There should be only one entry in PLT for a given
1965 symbol. Set howto to NULL after processing a PLT
1966 entry to guard against corrupted PLT. */
1967 p->howto = NULL;
1968 }
1969 offset += plt_entry_size;
1970 }
1971 }
1972
1973 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
1974 if (n == 0)
1975 {
1976 bad_return:
1977 count = -1;
1978 }
1979 else
1980 count = n;
1981
1982 for (j = 0; plts[j].name != NULL; j++)
1983 if (plts[j].contents != NULL)
1984 free (plts[j].contents);
1985
1986 free (dynrelbuf);
1987
1988 return count;
1989 }
1990
1991 /* Parse x86 GNU properties. */
1992
1993 enum elf_property_kind
1994 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
1995 bfd_byte *ptr, unsigned int datasz)
1996 {
1997 elf_property *prop;
1998
1999 switch (type)
2000 {
2001 case GNU_PROPERTY_X86_ISA_1_USED:
2002 case GNU_PROPERTY_X86_ISA_1_NEEDED:
2003 case GNU_PROPERTY_X86_FEATURE_1_AND:
2004 if (datasz != 4)
2005 {
2006 _bfd_error_handler
2007 ((type == GNU_PROPERTY_X86_ISA_1_USED
2008 ? _("error: %B: <corrupt x86 ISA used size: 0x%x>")
2009 : (type == GNU_PROPERTY_X86_ISA_1_NEEDED
2010 ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>")
2011 : _("error: %B: <corrupt x86 feature size: 0x%x>"))),
2012 abfd, datasz);
2013 return property_corrupt;
2014 }
2015 prop = _bfd_elf_get_property (abfd, type, datasz);
2016 /* Combine properties of the same type. */
2017 prop->u.number |= bfd_h_get_32 (abfd, ptr);
2018 prop->pr_kind = property_number;
2019 break;
2020
2021 default:
2022 return property_ignored;
2023 }
2024
2025 return property_number;
2026 }
2027
2028 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2029 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2030 should be merged with ABFD. */
2031
2032 bfd_boolean
2033 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2034 bfd *abfd ATTRIBUTE_UNUSED,
2035 elf_property *aprop,
2036 elf_property *bprop)
2037 {
2038 unsigned int number, features;
2039 bfd_boolean updated = FALSE;
2040 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2041
2042 switch (pr_type)
2043 {
2044 case GNU_PROPERTY_X86_ISA_1_USED:
2045 case GNU_PROPERTY_X86_ISA_1_NEEDED:
2046 if (aprop != NULL && bprop != NULL)
2047 {
2048 number = aprop->u.number;
2049 aprop->u.number = number | bprop->u.number;
2050 updated = number != (unsigned int) aprop->u.number;
2051 }
2052 else
2053 {
2054 /* Return TRUE if APROP is NULL to indicate that BPROP should
2055 be added to ABFD. */
2056 updated = aprop == NULL;
2057 }
2058 break;
2059
2060 case GNU_PROPERTY_X86_FEATURE_1_AND:
2061 /* Only one of APROP and BPROP can be NULL:
2062 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2063 2. If APROP is NULL, remove x86 feature.
2064 3. Otherwise, do nothing.
2065 */
2066 if (aprop != NULL && bprop != NULL)
2067 {
2068 features = 0;
2069 if (info->ibt)
2070 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2071 if (info->shstk)
2072 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2073 number = aprop->u.number;
2074 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2075 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2076 aprop->u.number = (number & bprop->u.number) | features;
2077 updated = number != (unsigned int) aprop->u.number;
2078 /* Remove the property if all feature bits are cleared. */
2079 if (aprop->u.number == 0)
2080 aprop->pr_kind = property_remove;
2081 }
2082 else
2083 {
2084 features = 0;
2085 if (info->ibt)
2086 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2087 if (info->shstk)
2088 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2089 if (features)
2090 {
2091 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2092 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2093 if (aprop != NULL)
2094 {
2095 number = aprop->u.number;
2096 aprop->u.number = number | features;
2097 updated = number != (unsigned int) aprop->u.number;
2098 }
2099 else
2100 {
2101 bprop->u.number |= features;
2102 updated = TRUE;
2103 }
2104 }
2105 else if (aprop != NULL)
2106 {
2107 aprop->pr_kind = property_remove;
2108 updated = TRUE;
2109 }
2110 }
2111 break;
2112
2113 default:
2114 /* Never should happen. */
2115 abort ();
2116 }
2117
2118 return updated;
2119 }
2120
2121 /* Set up x86 GNU properties. Return the first relocatable ELF input
2122 with GNU properties if found. Otherwise, return NULL. */
2123
2124 bfd *
2125 _bfd_x86_elf_link_setup_gnu_properties
2126 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2127 {
2128 bfd_boolean normal_target;
2129 bfd_boolean lazy_plt;
2130 asection *sec, *pltsec;
2131 bfd *dynobj;
2132 bfd_boolean use_ibt_plt;
2133 unsigned int plt_alignment, features;
2134 struct elf_x86_link_hash_table *htab;
2135 bfd *pbfd;
2136 bfd *ebfd = NULL;
2137 elf_property *prop;
2138 const struct elf_backend_data *bed;
2139 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2140 unsigned int got_align;
2141
2142 features = 0;
2143 if (info->ibt)
2144 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2145 if (info->shstk)
2146 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2147
2148 /* Find a normal input file with GNU property note. */
2149 for (pbfd = info->input_bfds;
2150 pbfd != NULL;
2151 pbfd = pbfd->link.next)
2152 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2153 && bfd_count_sections (pbfd) != 0)
2154 {
2155 ebfd = pbfd;
2156
2157 if (elf_properties (pbfd) != NULL)
2158 break;
2159 }
2160
2161 if (ebfd != NULL && features)
2162 {
2163 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
2164 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2165 prop = _bfd_elf_get_property (ebfd,
2166 GNU_PROPERTY_X86_FEATURE_1_AND,
2167 4);
2168 prop->u.number |= features;
2169 prop->pr_kind = property_number;
2170
2171 /* Create the GNU property note section if needed. */
2172 if (pbfd == NULL)
2173 {
2174 sec = bfd_make_section_with_flags (ebfd,
2175 NOTE_GNU_PROPERTY_SECTION_NAME,
2176 (SEC_ALLOC
2177 | SEC_LOAD
2178 | SEC_IN_MEMORY
2179 | SEC_READONLY
2180 | SEC_HAS_CONTENTS
2181 | SEC_DATA));
2182 if (sec == NULL)
2183 info->callbacks->einfo (_("%F: failed to create GNU property section\n"));
2184
2185 if (!bfd_set_section_alignment (ebfd, sec, class_align))
2186 {
2187 error_alignment:
2188 info->callbacks->einfo (_("%F%A: failed to align section\n"),
2189 sec);
2190 }
2191
2192 elf_section_type (sec) = SHT_NOTE;
2193 }
2194 }
2195
2196 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2197
2198 bed = get_elf_backend_data (info->output_bfd);
2199
2200 htab = elf_x86_hash_table (info, bed->target_id);
2201 if (htab == NULL)
2202 return pbfd;
2203
2204 htab->is_vxworks = init_table->is_vxworks;
2205 htab->r_info = init_table->r_info;
2206 htab->r_sym = init_table->r_sym;
2207
2208 if (bfd_link_relocatable (info))
2209 return pbfd;
2210
2211 use_ibt_plt = info->ibtplt || info->ibt;
2212 if (!use_ibt_plt && pbfd != NULL)
2213 {
2214 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2215 elf_property_list *p;
2216
2217 /* The property list is sorted in order of type. */
2218 for (p = elf_properties (pbfd); p; p = p->next)
2219 {
2220 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2221 {
2222 use_ibt_plt = !!(p->property.u.number
2223 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2224 break;
2225 }
2226 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2227 break;
2228 }
2229 }
2230
2231 dynobj = htab->elf.dynobj;
2232
2233 /* Set htab->elf.dynobj here so that there is no need to check and
2234 set it in check_relocs. */
2235 if (dynobj == NULL)
2236 {
2237 if (pbfd != NULL)
2238 {
2239 htab->elf.dynobj = pbfd;
2240 dynobj = pbfd;
2241 }
2242 else
2243 {
2244 bfd *abfd;
2245
2246 /* Find a normal input file to hold linker created
2247 sections. */
2248 for (abfd = info->input_bfds;
2249 abfd != NULL;
2250 abfd = abfd->link.next)
2251 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2252 && (abfd->flags
2253 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0)
2254 {
2255 htab->elf.dynobj = abfd;
2256 dynobj = abfd;
2257 break;
2258 }
2259 }
2260 }
2261
2262 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2263 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2264 canonical function address. */
2265 htab->plt.has_plt0 = 1;
2266 normal_target = init_table->normal_target;
2267
2268 if (normal_target)
2269 {
2270 if (use_ibt_plt)
2271 {
2272 htab->lazy_plt = init_table->lazy_ibt_plt;
2273 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2274 }
2275 else
2276 {
2277 htab->lazy_plt = init_table->lazy_plt;
2278 htab->non_lazy_plt = init_table->non_lazy_plt;
2279 }
2280 }
2281 else
2282 {
2283 htab->lazy_plt = init_table->lazy_plt;
2284 htab->non_lazy_plt = NULL;
2285 }
2286
2287 pltsec = htab->elf.splt;
2288
2289 /* If the non-lazy PLT is available, use it for all PLT entries if
2290 there are no PLT0 or no .plt section. */
2291 if (htab->non_lazy_plt != NULL
2292 && (!htab->plt.has_plt0 || pltsec == NULL))
2293 {
2294 lazy_plt = FALSE;
2295 if (bfd_link_pic (info))
2296 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2297 else
2298 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2299 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2300 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2301 htab->plt.plt_got_insn_size
2302 = htab->non_lazy_plt->plt_got_insn_size;
2303 htab->plt.eh_frame_plt_size
2304 = htab->non_lazy_plt->eh_frame_plt_size;
2305 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2306 }
2307 else
2308 {
2309 lazy_plt = TRUE;
2310 if (bfd_link_pic (info))
2311 {
2312 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2313 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2314 }
2315 else
2316 {
2317 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2318 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2319 }
2320 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2321 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2322 htab->plt.plt_got_insn_size
2323 = htab->lazy_plt->plt_got_insn_size;
2324 htab->plt.eh_frame_plt_size
2325 = htab->lazy_plt->eh_frame_plt_size;
2326 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2327 }
2328
2329 /* Return if there are no normal input files. */
2330 if (dynobj == NULL)
2331 return pbfd;
2332
2333 if (htab->is_vxworks
2334 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2335 &htab->srelplt2))
2336 {
2337 info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n"));
2338 return pbfd;
2339 }
2340
2341 /* Since create_dynamic_sections isn't always called, but GOT
2342 relocations need GOT relocations, create them here so that we
2343 don't need to do it in check_relocs. */
2344 if (htab->elf.sgot == NULL
2345 && !_bfd_elf_create_got_section (dynobj, info))
2346 info->callbacks->einfo (_("%F: failed to create GOT sections\n"));
2347
2348 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2349
2350 /* Align .got and .got.plt sections to their entry size. Do it here
2351 instead of in create_dynamic_sections so that they are always
2352 properly aligned even if create_dynamic_sections isn't called. */
2353 sec = htab->elf.sgot;
2354 if (!bfd_set_section_alignment (dynobj, sec, got_align))
2355 goto error_alignment;
2356
2357 sec = htab->elf.sgotplt;
2358 if (!bfd_set_section_alignment (dynobj, sec, got_align))
2359 goto error_alignment;
2360
2361 /* Create the ifunc sections here so that check_relocs can be
2362 simplified. */
2363 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2364 info->callbacks->einfo (_("%F: failed to create ifunc sections\n"));
2365
2366 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2367
2368 if (pltsec != NULL)
2369 {
2370 /* Whe creating executable, set the contents of the .interp
2371 section to the interpreter. */
2372 if (bfd_link_executable (info) && !info->nointerp)
2373 {
2374 asection *s = bfd_get_linker_section (dynobj, ".interp");
2375 if (s == NULL)
2376 abort ();
2377 s->size = htab->dynamic_interpreter_size;
2378 s->contents = (unsigned char *) htab->dynamic_interpreter;
2379 htab->interp = s;
2380 }
2381
2382 /* Don't change PLT section alignment for NaCl since it uses
2383 64-byte PLT entry and sets PLT section alignment to 32
2384 bytes. Don't create additional PLT sections for NaCl. */
2385 if (normal_target)
2386 {
2387 flagword pltflags = (bed->dynamic_sec_flags
2388 | SEC_ALLOC
2389 | SEC_CODE
2390 | SEC_LOAD
2391 | SEC_READONLY);
2392 unsigned int non_lazy_plt_alignment
2393 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2394
2395 sec = pltsec;
2396 if (!bfd_set_section_alignment (sec->owner, sec,
2397 plt_alignment))
2398 goto error_alignment;
2399
2400 /* Create the GOT procedure linkage table. */
2401 sec = bfd_make_section_anyway_with_flags (dynobj,
2402 ".plt.got",
2403 pltflags);
2404 if (sec == NULL)
2405 info->callbacks->einfo (_("%F: failed to create GOT PLT section\n"));
2406
2407 if (!bfd_set_section_alignment (dynobj, sec,
2408 non_lazy_plt_alignment))
2409 goto error_alignment;
2410
2411 htab->plt_got = sec;
2412
2413 if (lazy_plt)
2414 {
2415 sec = NULL;
2416
2417 if (use_ibt_plt)
2418 {
2419 /* Create the second PLT for Intel IBT support. IBT
2420 PLT is supported only for non-NaCl target and is
2421 is needed only for lazy binding. */
2422 sec = bfd_make_section_anyway_with_flags (dynobj,
2423 ".plt.sec",
2424 pltflags);
2425 if (sec == NULL)
2426 info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n"));
2427
2428 if (!bfd_set_section_alignment (dynobj, sec,
2429 plt_alignment))
2430 goto error_alignment;
2431 }
2432 else if (info->bndplt && ABI_64_P (dynobj))
2433 {
2434 /* Create the second PLT for Intel MPX support. MPX
2435 PLT is supported only for non-NaCl target in 64-bit
2436 mode and is needed only for lazy binding. */
2437 sec = bfd_make_section_anyway_with_flags (dynobj,
2438 ".plt.sec",
2439 pltflags);
2440 if (sec == NULL)
2441 info->callbacks->einfo (_("%F: failed to create BND PLT section\n"));
2442
2443 if (!bfd_set_section_alignment (dynobj, sec,
2444 non_lazy_plt_alignment))
2445 goto error_alignment;
2446 }
2447
2448 htab->plt_second = sec;
2449 }
2450 }
2451
2452 if (!info->no_ld_generated_unwind_info)
2453 {
2454 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
2455 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
2456 | SEC_LINKER_CREATED);
2457
2458 sec = bfd_make_section_anyway_with_flags (dynobj,
2459 ".eh_frame",
2460 flags);
2461 if (sec == NULL)
2462 info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n"));
2463
2464 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2465 goto error_alignment;
2466
2467 htab->plt_eh_frame = sec;
2468
2469 if (htab->plt_got != NULL)
2470 {
2471 sec = bfd_make_section_anyway_with_flags (dynobj,
2472 ".eh_frame",
2473 flags);
2474 if (sec == NULL)
2475 info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n"));
2476
2477 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2478 goto error_alignment;
2479
2480 htab->plt_got_eh_frame = sec;
2481 }
2482
2483 if (htab->plt_second != NULL)
2484 {
2485 sec = bfd_make_section_anyway_with_flags (dynobj,
2486 ".eh_frame",
2487 flags);
2488 if (sec == NULL)
2489 info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n"));
2490
2491 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2492 goto error_alignment;
2493
2494 htab->plt_second_eh_frame = sec;
2495 }
2496 }
2497 }
2498
2499 if (normal_target)
2500 {
2501 /* The .iplt section is used for IFUNC symbols in static
2502 executables. */
2503 sec = htab->elf.iplt;
2504 if (sec != NULL
2505 && !bfd_set_section_alignment (sec->owner, sec,
2506 plt_alignment))
2507 goto error_alignment;
2508 }
2509
2510 return pbfd;
2511 }
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