e385ddb539127bb0ec7c4238788a8c992fe9ad37
[deliverable/binutils-gdb.git] / bfd / elfxx-x86.c
1 /* x86 specific support for ELF
2 Copyright (C) 2017-2020 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 /* We can't use the GOT PLT if pointer equality is needed since
112 finish_dynamic_symbol won't clear symbol value and the dynamic
113 linker won't update the GOT slot. We will get into an infinite
114 loop at run-time. */
115 if (htab->plt_got != NULL
116 && h->type != STT_GNU_IFUNC
117 && !h->pointer_equality_needed
118 && h->plt.refcount > 0
119 && h->got.refcount > 0)
120 {
121 /* Don't use the regular PLT if there are both GOT and GOTPLT
122 reloctions. */
123 h->plt.offset = (bfd_vma) -1;
124
125 /* Use the GOT PLT. */
126 eh->plt_got.refcount = 1;
127 }
128
129 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
130 here if it is defined and referenced in a non-shared object. */
131 if (h->type == STT_GNU_IFUNC
132 && h->def_regular)
133 {
134 if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &h->dyn_relocs,
135 &htab->readonly_dynrelocs_against_ifunc,
136 plt_entry_size,
137 (htab->plt.has_plt0
138 * plt_entry_size),
139 htab->got_entry_size,
140 TRUE))
141 {
142 asection *s = htab->plt_second;
143 if (h->plt.offset != (bfd_vma) -1 && s != NULL)
144 {
145 /* Use the second PLT section if it is created. */
146 eh->plt_second.offset = s->size;
147
148 /* Make room for this entry in the second PLT section. */
149 s->size += htab->non_lazy_plt->plt_entry_size;
150 }
151
152 return TRUE;
153 }
154 else
155 return FALSE;
156 }
157 /* Don't create the PLT entry if there are only function pointer
158 relocations which can be resolved at run-time. */
159 else if (htab->elf.dynamic_sections_created
160 && (h->plt.refcount > 0
161 || eh->plt_got.refcount > 0))
162 {
163 bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
164
165 /* Make sure this symbol is output as a dynamic symbol.
166 Undefined weak syms won't yet be marked as dynamic. */
167 if (h->dynindx == -1
168 && !h->forced_local
169 && !resolved_to_zero
170 && h->root.type == bfd_link_hash_undefweak)
171 {
172 if (! bfd_elf_link_record_dynamic_symbol (info, h))
173 return FALSE;
174 }
175
176 if (bfd_link_pic (info)
177 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
178 {
179 asection *s = htab->elf.splt;
180 asection *second_s = htab->plt_second;
181 asection *got_s = htab->plt_got;
182 bfd_boolean use_plt;
183
184 /* If this is the first .plt entry, make room for the special
185 first entry. The .plt section is used by prelink to undo
186 prelinking for dynamic relocations. */
187 if (s->size == 0)
188 s->size = htab->plt.has_plt0 * plt_entry_size;
189
190 if (use_plt_got)
191 eh->plt_got.offset = got_s->size;
192 else
193 {
194 h->plt.offset = s->size;
195 if (second_s)
196 eh->plt_second.offset = second_s->size;
197 }
198
199 /* If this symbol is not defined in a regular file, and we are
200 generating PDE, then set the symbol to this location in the
201 .plt. This is required to make function pointers compare
202 as equal between PDE and the shared library.
203
204 NB: If PLT is PC-relative, we can use the .plt in PIE for
205 function address. */
206 if (h->def_regular)
207 use_plt = FALSE;
208 else if (htab->pcrel_plt)
209 use_plt = ! bfd_link_dll (info);
210 else
211 use_plt = bfd_link_pde (info);
212 if (use_plt)
213 {
214 if (use_plt_got)
215 {
216 /* We need to make a call to the entry of the GOT PLT
217 instead of regular PLT entry. */
218 h->root.u.def.section = got_s;
219 h->root.u.def.value = eh->plt_got.offset;
220 }
221 else
222 {
223 if (second_s)
224 {
225 /* We need to make a call to the entry of the
226 second PLT instead of regular PLT entry. */
227 h->root.u.def.section = second_s;
228 h->root.u.def.value = eh->plt_second.offset;
229 }
230 else
231 {
232 h->root.u.def.section = s;
233 h->root.u.def.value = h->plt.offset;
234 }
235 }
236 }
237
238 /* Make room for this entry. */
239 if (use_plt_got)
240 got_s->size += htab->non_lazy_plt->plt_entry_size;
241 else
242 {
243 s->size += plt_entry_size;
244 if (second_s)
245 second_s->size += htab->non_lazy_plt->plt_entry_size;
246
247 /* We also need to make an entry in the .got.plt section,
248 which will be placed in the .got section by the linker
249 script. */
250 htab->elf.sgotplt->size += htab->got_entry_size;
251
252 /* There should be no PLT relocation against resolved
253 undefined weak symbol in executable. */
254 if (!resolved_to_zero)
255 {
256 /* We also need to make an entry in the .rel.plt
257 section. */
258 htab->elf.srelplt->size += htab->sizeof_reloc;
259 htab->elf.srelplt->reloc_count++;
260 }
261 }
262
263 if (htab->target_os == is_vxworks && !bfd_link_pic (info))
264 {
265 /* VxWorks has a second set of relocations for each PLT entry
266 in executables. They go in a separate relocation section,
267 which is processed by the kernel loader. */
268
269 /* There are two relocations for the initial PLT entry: an
270 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
271 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
272
273 asection *srelplt2 = htab->srelplt2;
274 if (h->plt.offset == plt_entry_size)
275 srelplt2->size += (htab->sizeof_reloc * 2);
276
277 /* There are two extra relocations for each subsequent PLT entry:
278 an R_386_32 relocation for the GOT entry, and an R_386_32
279 relocation for the PLT entry. */
280
281 srelplt2->size += (htab->sizeof_reloc * 2);
282 }
283 }
284 else
285 {
286 eh->plt_got.offset = (bfd_vma) -1;
287 h->plt.offset = (bfd_vma) -1;
288 h->needs_plt = 0;
289 }
290 }
291 else
292 {
293 eh->plt_got.offset = (bfd_vma) -1;
294 h->plt.offset = (bfd_vma) -1;
295 h->needs_plt = 0;
296 }
297
298 eh->tlsdesc_got = (bfd_vma) -1;
299
300 /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the
301 binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For
302 x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary,
303 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
304 if (h->got.refcount > 0
305 && bfd_link_executable (info)
306 && h->dynindx == -1
307 && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
308 h->got.offset = (bfd_vma) -1;
309 else if (h->got.refcount > 0)
310 {
311 asection *s;
312 bfd_boolean dyn;
313 int tls_type = elf_x86_hash_entry (h)->tls_type;
314
315 /* Make sure this symbol is output as a dynamic symbol.
316 Undefined weak syms won't yet be marked as dynamic. */
317 if (h->dynindx == -1
318 && !h->forced_local
319 && !resolved_to_zero
320 && h->root.type == bfd_link_hash_undefweak)
321 {
322 if (! bfd_elf_link_record_dynamic_symbol (info, h))
323 return FALSE;
324 }
325
326 s = htab->elf.sgot;
327 if (GOT_TLS_GDESC_P (tls_type))
328 {
329 eh->tlsdesc_got = htab->elf.sgotplt->size
330 - elf_x86_compute_jump_table_size (htab);
331 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
332 h->got.offset = (bfd_vma) -2;
333 }
334 if (! GOT_TLS_GDESC_P (tls_type)
335 || GOT_TLS_GD_P (tls_type))
336 {
337 h->got.offset = s->size;
338 s->size += htab->got_entry_size;
339 /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT
340 slots. */
341 if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
342 s->size += htab->got_entry_size;
343 }
344 dyn = htab->elf.dynamic_sections_created;
345 /* R_386_TLS_IE_32 needs one dynamic relocation,
346 R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
347 (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
348 need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local
349 symbol and two if global. No dynamic relocation against
350 resolved undefined weak symbol in executable. No dynamic
351 relocation against non-preemptible absolute symbol. */
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 && !(h->dynindx == -1
365 && ABS_SYMBOL_P (h)))
366 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
367 htab->elf.srelgot->size += htab->sizeof_reloc;
368 if (GOT_TLS_GDESC_P (tls_type))
369 {
370 htab->elf.srelplt->size += htab->sizeof_reloc;
371 if (bed->target_id == X86_64_ELF_DATA)
372 htab->tlsdesc_plt = (bfd_vma) -1;
373 }
374 }
375 else
376 h->got.offset = (bfd_vma) -1;
377
378 if (h->dyn_relocs == NULL)
379 return TRUE;
380
381 /* In the shared -Bsymbolic case, discard space allocated for
382 dynamic pc-relative relocs against symbols which turn out to be
383 defined in regular objects. For the normal shared case, discard
384 space for pc-relative relocs that have become local due to symbol
385 visibility changes. */
386
387 if (bfd_link_pic (info))
388 {
389 /* Relocs that use pc_count are those that appear on a call
390 insn, or certain REL relocs that can generated via assembly.
391 We want calls to protected symbols to resolve directly to the
392 function rather than going via the plt. If people want
393 function pointer comparisons to work as expected then they
394 should avoid writing weird assembly. */
395 if (SYMBOL_CALLS_LOCAL (info, h))
396 {
397 struct elf_dyn_relocs **pp;
398
399 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
400 {
401 p->count -= p->pc_count;
402 p->pc_count = 0;
403 if (p->count == 0)
404 *pp = p->next;
405 else
406 pp = &p->next;
407 }
408 }
409
410 if (htab->target_os == is_vxworks)
411 {
412 struct elf_dyn_relocs **pp;
413 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
414 {
415 if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
416 *pp = p->next;
417 else
418 pp = &p->next;
419 }
420 }
421
422 /* Also discard relocs on undefined weak syms with non-default
423 visibility or in PIE. */
424 if (h->dyn_relocs != NULL)
425 {
426 if (h->root.type == bfd_link_hash_undefweak)
427 {
428 /* Undefined weak symbol is never bound locally in shared
429 library. */
430 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
431 || resolved_to_zero)
432 {
433 if (bed->target_id == I386_ELF_DATA
434 && h->non_got_ref)
435 {
436 /* Keep dynamic non-GOT/non-PLT relocation so
437 that we can branch to 0 without PLT. */
438 struct elf_dyn_relocs **pp;
439
440 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
441 if (p->pc_count == 0)
442 *pp = p->next;
443 else
444 {
445 /* Remove non-R_386_PC32 relocation. */
446 p->count = p->pc_count;
447 pp = &p->next;
448 }
449
450 /* Make sure undefined weak symbols are output
451 as dynamic symbols in PIEs for dynamic non-GOT
452 non-PLT reloations. */
453 if (h->dyn_relocs != NULL
454 && !bfd_elf_link_record_dynamic_symbol (info, h))
455 return FALSE;
456 }
457 else
458 h->dyn_relocs = NULL;
459 }
460 else if (h->dynindx == -1
461 && !h->forced_local
462 && !bfd_elf_link_record_dynamic_symbol (info, h))
463 return FALSE;
464 }
465 else if (bfd_link_executable (info)
466 && (h->needs_copy || eh->needs_copy)
467 && h->def_dynamic
468 && !h->def_regular)
469 {
470 /* NB: needs_copy is set only for x86-64. For PIE,
471 discard space for pc-relative relocs against symbols
472 which turn out to need copy relocs. */
473 struct elf_dyn_relocs **pp;
474
475 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
476 {
477 if (p->pc_count != 0)
478 *pp = p->next;
479 else
480 pp = &p->next;
481 }
482 }
483 }
484 }
485 else if (ELIMINATE_COPY_RELOCS)
486 {
487 /* For the non-shared case, discard space for relocs against
488 symbols which turn out to need copy relocs or are not
489 dynamic. Keep dynamic relocations for run-time function
490 pointer initialization. */
491
492 if ((!h->non_got_ref
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 h->dyn_relocs = NULL;
517
518 keep: ;
519 }
520
521 /* Finally, allocate space. */
522 for (p = h->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 dynamic relocs for H that apply to read-only sections. */
536
537 static asection *
538 readonly_dynrelocs (struct elf_link_hash_entry *h)
539 {
540 struct elf_dyn_relocs *p;
541
542 for (p = h->dyn_relocs; p != NULL; p = p->next)
543 {
544 asection *s = p->sec->output_section;
545
546 if (s != NULL && (s->flags & SEC_READONLY) != 0)
547 return p->sec;
548 }
549 return NULL;
550 }
551
552 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
553 read-only sections. */
554
555 static bfd_boolean
556 maybe_set_textrel (struct elf_link_hash_entry *h, void *inf)
557 {
558 asection *sec;
559
560 if (h->root.type == bfd_link_hash_indirect)
561 return TRUE;
562
563 /* Skip local IFUNC symbols. */
564 if (h->forced_local && h->type == STT_GNU_IFUNC)
565 return TRUE;
566
567 sec = readonly_dynrelocs (h);
568 if (sec != NULL)
569 {
570 struct bfd_link_info *info = (struct bfd_link_info *) inf;
571
572 info->flags |= DF_TEXTREL;
573 /* xgettext:c-format */
574 info->callbacks->minfo (_("%pB: dynamic relocation against `%pT' "
575 "in read-only section `%pA'\n"),
576 sec->owner, h->root.root.string, sec);
577
578 if (bfd_link_textrel_check (info))
579 /* xgettext:c-format */
580 info->callbacks->einfo (_("%P: %pB: warning: relocation against `%s' "
581 "in read-only section `%pA'\n"),
582 sec->owner, h->root.root.string, sec);
583
584 /* Not an error, just cut short the traversal. */
585 return FALSE;
586 }
587 return TRUE;
588 }
589
590 /* Allocate space in .plt, .got and associated reloc sections for
591 local dynamic relocs. */
592
593 static bfd_boolean
594 elf_x86_allocate_local_dynreloc (void **slot, void *inf)
595 {
596 struct elf_link_hash_entry *h
597 = (struct elf_link_hash_entry *) *slot;
598
599 if (h->type != STT_GNU_IFUNC
600 || !h->def_regular
601 || !h->ref_regular
602 || !h->forced_local
603 || h->root.type != bfd_link_hash_defined)
604 abort ();
605
606 return elf_x86_allocate_dynrelocs (h, inf);
607 }
608
609 /* Find and/or create a hash entry for local symbol. */
610
611 struct elf_link_hash_entry *
612 _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab,
613 bfd *abfd, const Elf_Internal_Rela *rel,
614 bfd_boolean create)
615 {
616 struct elf_x86_link_hash_entry e, *ret;
617 asection *sec = abfd->sections;
618 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id,
619 htab->r_sym (rel->r_info));
620 void **slot;
621
622 e.elf.indx = sec->id;
623 e.elf.dynstr_index = htab->r_sym (rel->r_info);
624 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h,
625 create ? INSERT : NO_INSERT);
626
627 if (!slot)
628 return NULL;
629
630 if (*slot)
631 {
632 ret = (struct elf_x86_link_hash_entry *) *slot;
633 return &ret->elf;
634 }
635
636 ret = (struct elf_x86_link_hash_entry *)
637 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory,
638 sizeof (struct elf_x86_link_hash_entry));
639 if (ret)
640 {
641 memset (ret, 0, sizeof (*ret));
642 ret->elf.indx = sec->id;
643 ret->elf.dynstr_index = htab->r_sym (rel->r_info);
644 ret->elf.dynindx = -1;
645 ret->plt_got.offset = (bfd_vma) -1;
646 *slot = ret;
647 }
648 return &ret->elf;
649 }
650
651 /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN
652 SYNC WITH _bfd_elf_link_hash_newfunc. */
653
654 struct bfd_hash_entry *
655 _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry,
656 struct bfd_hash_table *table,
657 const char *string)
658 {
659 /* Allocate the structure if it has not already been allocated by a
660 subclass. */
661 if (entry == NULL)
662 {
663 entry = (struct bfd_hash_entry *)
664 bfd_hash_allocate (table,
665 sizeof (struct elf_x86_link_hash_entry));
666 if (entry == NULL)
667 return entry;
668 }
669
670 /* Call the allocation method of the superclass. */
671 entry = _bfd_link_hash_newfunc (entry, table, string);
672 if (entry != NULL)
673 {
674 struct elf_x86_link_hash_entry *eh
675 = (struct elf_x86_link_hash_entry *) entry;
676 struct elf_link_hash_table *htab
677 = (struct elf_link_hash_table *) table;
678
679 memset (&eh->elf.size, 0,
680 (sizeof (struct elf_x86_link_hash_entry)
681 - offsetof (struct elf_link_hash_entry, size)));
682 /* Set local fields. */
683 eh->elf.indx = -1;
684 eh->elf.dynindx = -1;
685 eh->elf.got = htab->init_got_refcount;
686 eh->elf.plt = htab->init_plt_refcount;
687 /* Assume that we have been called by a non-ELF symbol reader.
688 This flag is then reset by the code which reads an ELF input
689 file. This ensures that a symbol created by a non-ELF symbol
690 reader will have the flag set correctly. */
691 eh->elf.non_elf = 1;
692 eh->plt_second.offset = (bfd_vma) -1;
693 eh->plt_got.offset = (bfd_vma) -1;
694 eh->tlsdesc_got = (bfd_vma) -1;
695 eh->zero_undefweak = 1;
696 }
697
698 return entry;
699 }
700
701 /* Compute a hash of a local hash entry. We use elf_link_hash_entry
702 for local symbol so that we can handle local STT_GNU_IFUNC symbols
703 as global symbol. We reuse indx and dynstr_index for local symbol
704 hash since they aren't used by global symbols in this backend. */
705
706 hashval_t
707 _bfd_x86_elf_local_htab_hash (const void *ptr)
708 {
709 struct elf_link_hash_entry *h
710 = (struct elf_link_hash_entry *) ptr;
711 return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index);
712 }
713
714 /* Compare local hash entries. */
715
716 int
717 _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2)
718 {
719 struct elf_link_hash_entry *h1
720 = (struct elf_link_hash_entry *) ptr1;
721 struct elf_link_hash_entry *h2
722 = (struct elf_link_hash_entry *) ptr2;
723
724 return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index;
725 }
726
727 /* Destroy an x86 ELF linker hash table. */
728
729 static void
730 elf_x86_link_hash_table_free (bfd *obfd)
731 {
732 struct elf_x86_link_hash_table *htab
733 = (struct elf_x86_link_hash_table *) obfd->link.hash;
734
735 if (htab->loc_hash_table)
736 htab_delete (htab->loc_hash_table);
737 if (htab->loc_hash_memory)
738 objalloc_free ((struct objalloc *) htab->loc_hash_memory);
739 _bfd_elf_link_hash_table_free (obfd);
740 }
741
742 static bfd_boolean
743 elf_i386_is_reloc_section (const char *secname)
744 {
745 return CONST_STRNEQ (secname, ".rel");
746 }
747
748 static bfd_boolean
749 elf_x86_64_is_reloc_section (const char *secname)
750 {
751 return CONST_STRNEQ (secname, ".rela");
752 }
753
754 /* Create an x86 ELF linker hash table. */
755
756 struct bfd_link_hash_table *
757 _bfd_x86_elf_link_hash_table_create (bfd *abfd)
758 {
759 struct elf_x86_link_hash_table *ret;
760 const struct elf_backend_data *bed;
761 size_t amt = sizeof (struct elf_x86_link_hash_table);
762
763 ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt);
764 if (ret == NULL)
765 return NULL;
766
767 bed = get_elf_backend_data (abfd);
768 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd,
769 _bfd_x86_elf_link_hash_newfunc,
770 sizeof (struct elf_x86_link_hash_entry),
771 bed->target_id))
772 {
773 free (ret);
774 return NULL;
775 }
776
777 if (bed->target_id == X86_64_ELF_DATA)
778 {
779 ret->is_reloc_section = elf_x86_64_is_reloc_section;
780 ret->dt_reloc = DT_RELA;
781 ret->dt_reloc_sz = DT_RELASZ;
782 ret->dt_reloc_ent = DT_RELAENT;
783 ret->got_entry_size = 8;
784 ret->pcrel_plt = TRUE;
785 ret->tls_get_addr = "__tls_get_addr";
786 }
787 if (ABI_64_P (abfd))
788 {
789 ret->sizeof_reloc = sizeof (Elf64_External_Rela);
790 ret->pointer_r_type = R_X86_64_64;
791 ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER;
792 ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER;
793 }
794 else
795 {
796 if (bed->target_id == X86_64_ELF_DATA)
797 {
798 ret->sizeof_reloc = sizeof (Elf32_External_Rela);
799 ret->pointer_r_type = R_X86_64_32;
800 ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER;
801 ret->dynamic_interpreter_size
802 = sizeof ELFX32_DYNAMIC_INTERPRETER;
803 }
804 else
805 {
806 ret->is_reloc_section = elf_i386_is_reloc_section;
807 ret->dt_reloc = DT_REL;
808 ret->dt_reloc_sz = DT_RELSZ;
809 ret->dt_reloc_ent = DT_RELENT;
810 ret->sizeof_reloc = sizeof (Elf32_External_Rel);
811 ret->got_entry_size = 4;
812 ret->pcrel_plt = FALSE;
813 ret->pointer_r_type = R_386_32;
814 ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER;
815 ret->dynamic_interpreter_size
816 = sizeof ELF32_DYNAMIC_INTERPRETER;
817 ret->tls_get_addr = "___tls_get_addr";
818 }
819 }
820 ret->target_id = bed->target_id;
821 ret->target_os = get_elf_x86_backend_data (abfd)->target_os;
822
823 ret->loc_hash_table = htab_try_create (1024,
824 _bfd_x86_elf_local_htab_hash,
825 _bfd_x86_elf_local_htab_eq,
826 NULL);
827 ret->loc_hash_memory = objalloc_create ();
828 if (!ret->loc_hash_table || !ret->loc_hash_memory)
829 {
830 elf_x86_link_hash_table_free (abfd);
831 return NULL;
832 }
833 ret->elf.root.hash_table_free = elf_x86_link_hash_table_free;
834
835 return &ret->elf.root;
836 }
837
838 /* Sort relocs into address order. */
839
840 int
841 _bfd_x86_elf_compare_relocs (const void *ap, const void *bp)
842 {
843 const arelent *a = * (const arelent **) ap;
844 const arelent *b = * (const arelent **) bp;
845
846 if (a->address > b->address)
847 return 1;
848 else if (a->address < b->address)
849 return -1;
850 else
851 return 0;
852 }
853
854 /* Mark symbol, NAME, as locally defined by linker if it is referenced
855 and not defined in a relocatable object file. */
856
857 static void
858 elf_x86_linker_defined (struct bfd_link_info *info, const char *name)
859 {
860 struct elf_link_hash_entry *h;
861
862 h = elf_link_hash_lookup (elf_hash_table (info), name,
863 FALSE, FALSE, FALSE);
864 if (h == NULL)
865 return;
866
867 while (h->root.type == bfd_link_hash_indirect)
868 h = (struct elf_link_hash_entry *) h->root.u.i.link;
869
870 if (h->root.type == bfd_link_hash_new
871 || h->root.type == bfd_link_hash_undefined
872 || h->root.type == bfd_link_hash_undefweak
873 || h->root.type == bfd_link_hash_common
874 || (!h->def_regular && h->def_dynamic))
875 {
876 elf_x86_hash_entry (h)->local_ref = 2;
877 elf_x86_hash_entry (h)->linker_def = 1;
878 }
879 }
880
881 /* Hide a linker-defined symbol, NAME, with hidden visibility. */
882
883 static void
884 elf_x86_hide_linker_defined (struct bfd_link_info *info,
885 const char *name)
886 {
887 struct elf_link_hash_entry *h;
888
889 h = elf_link_hash_lookup (elf_hash_table (info), name,
890 FALSE, FALSE, FALSE);
891 if (h == NULL)
892 return;
893
894 while (h->root.type == bfd_link_hash_indirect)
895 h = (struct elf_link_hash_entry *) h->root.u.i.link;
896
897 if (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
898 || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN)
899 _bfd_elf_link_hash_hide_symbol (info, h, TRUE);
900 }
901
902 bfd_boolean
903 _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
904 {
905 if (!bfd_link_relocatable (info))
906 {
907 /* Check for __tls_get_addr reference. */
908 struct elf_x86_link_hash_table *htab;
909 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
910 htab = elf_x86_hash_table (info, bed->target_id);
911 if (htab)
912 {
913 struct elf_link_hash_entry *h;
914
915 h = elf_link_hash_lookup (elf_hash_table (info),
916 htab->tls_get_addr,
917 FALSE, FALSE, FALSE);
918 if (h != NULL)
919 {
920 elf_x86_hash_entry (h)->tls_get_addr = 1;
921
922 /* Check the versioned __tls_get_addr symbol. */
923 while (h->root.type == bfd_link_hash_indirect)
924 {
925 h = (struct elf_link_hash_entry *) h->root.u.i.link;
926 elf_x86_hash_entry (h)->tls_get_addr = 1;
927 }
928 }
929
930 /* "__ehdr_start" will be defined by linker as a hidden symbol
931 later if it is referenced and not defined. */
932 elf_x86_linker_defined (info, "__ehdr_start");
933
934 if (bfd_link_executable (info))
935 {
936 /* References to __bss_start, _end and _edata should be
937 locally resolved within executables. */
938 elf_x86_linker_defined (info, "__bss_start");
939 elf_x86_linker_defined (info, "_end");
940 elf_x86_linker_defined (info, "_edata");
941 }
942 else
943 {
944 /* Hide hidden __bss_start, _end and _edata in shared
945 libraries. */
946 elf_x86_hide_linker_defined (info, "__bss_start");
947 elf_x86_hide_linker_defined (info, "_end");
948 elf_x86_hide_linker_defined (info, "_edata");
949 }
950 }
951 }
952
953 /* Invoke the regular ELF backend linker to do all the work. */
954 return _bfd_elf_link_check_relocs (abfd, info);
955 }
956
957 bfd_boolean
958 _bfd_elf_x86_valid_reloc_p (asection *input_section,
959 struct bfd_link_info *info,
960 struct elf_x86_link_hash_table *htab,
961 const Elf_Internal_Rela *rel,
962 struct elf_link_hash_entry *h,
963 Elf_Internal_Sym *sym,
964 Elf_Internal_Shdr *symtab_hdr,
965 bfd_boolean *no_dynreloc_p)
966 {
967 bfd_boolean valid_p = TRUE;
968
969 *no_dynreloc_p = FALSE;
970
971 /* Check If relocation against non-preemptible absolute symbol is
972 valid in PIC. FIXME: Can't use SYMBOL_REFERENCES_LOCAL_P since
973 it may call _bfd_elf_link_hide_sym_by_version and result in
974 ld-elfvers/ vers21 test failure. */
975 if (bfd_link_pic (info)
976 && (h == NULL || SYMBOL_REFERENCES_LOCAL (info, h)))
977 {
978 const struct elf_backend_data *bed;
979 unsigned int r_type;
980 Elf_Internal_Rela irel;
981
982 /* Skip non-absolute symbol. */
983 if (h)
984 {
985 if (!ABS_SYMBOL_P (h))
986 return valid_p;
987 }
988 else if (sym->st_shndx != SHN_ABS)
989 return valid_p;
990
991 bed = get_elf_backend_data (input_section->owner);
992 r_type = ELF32_R_TYPE (rel->r_info);
993 irel = *rel;
994
995 /* Only allow relocations against absolute symbol, which can be
996 resolved as absolute value + addend. GOTPCREL relocations
997 are allowed since absolute value + addend is stored in the
998 GOT slot. */
999 if (bed->target_id == X86_64_ELF_DATA)
1000 {
1001 r_type &= ~R_X86_64_converted_reloc_bit;
1002 valid_p = (r_type == R_X86_64_64
1003 || r_type == R_X86_64_32
1004 || r_type == R_X86_64_32S
1005 || r_type == R_X86_64_16
1006 || r_type == R_X86_64_8
1007 || r_type == R_X86_64_GOTPCREL
1008 || r_type == R_X86_64_GOTPCRELX
1009 || r_type == R_X86_64_REX_GOTPCRELX);
1010 if (!valid_p)
1011 {
1012 unsigned int r_symndx = htab->r_sym (rel->r_info);
1013 irel.r_info = htab->r_info (r_symndx, r_type);
1014 }
1015 }
1016 else
1017 valid_p = (r_type == R_386_32
1018 || r_type == R_386_16
1019 || r_type == R_386_8);
1020
1021 if (valid_p)
1022 *no_dynreloc_p = TRUE;
1023 else
1024 {
1025 const char *name;
1026 arelent internal_reloc;
1027
1028 if (!bed->elf_info_to_howto (input_section->owner,
1029 &internal_reloc, &irel)
1030 || internal_reloc.howto == NULL)
1031 abort ();
1032
1033 if (h)
1034 name = h->root.root.string;
1035 else
1036 name = bfd_elf_sym_name (input_section->owner, symtab_hdr,
1037 sym, NULL);
1038 info->callbacks->einfo
1039 /* xgettext:c-format */
1040 (_("%F%P: %pB: relocation %s against absolute symbol "
1041 "`%s' in section `%pA' is disallowed\n"),
1042 input_section->owner, internal_reloc.howto->name, name,
1043 input_section);
1044 bfd_set_error (bfd_error_bad_value);
1045 }
1046 }
1047
1048 return valid_p;
1049 }
1050
1051 /* Set the sizes of the dynamic sections. */
1052
1053 bfd_boolean
1054 _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
1055 struct bfd_link_info *info)
1056 {
1057 struct elf_x86_link_hash_table *htab;
1058 bfd *dynobj;
1059 asection *s;
1060 bfd_boolean relocs;
1061 bfd *ibfd;
1062 const struct elf_backend_data *bed
1063 = get_elf_backend_data (output_bfd);
1064
1065 htab = elf_x86_hash_table (info, bed->target_id);
1066 if (htab == NULL)
1067 return FALSE;
1068 dynobj = htab->elf.dynobj;
1069 if (dynobj == NULL)
1070 abort ();
1071
1072 /* Set up .got offsets for local syms, and space for local dynamic
1073 relocs. */
1074 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
1075 {
1076 bfd_signed_vma *local_got;
1077 bfd_signed_vma *end_local_got;
1078 char *local_tls_type;
1079 bfd_vma *local_tlsdesc_gotent;
1080 bfd_size_type locsymcount;
1081 Elf_Internal_Shdr *symtab_hdr;
1082 asection *srel;
1083
1084 if (! is_x86_elf (ibfd, htab))
1085 continue;
1086
1087 for (s = ibfd->sections; s != NULL; s = s->next)
1088 {
1089 struct elf_dyn_relocs *p;
1090
1091 for (p = ((struct elf_dyn_relocs *)
1092 elf_section_data (s)->local_dynrel);
1093 p != NULL;
1094 p = p->next)
1095 {
1096 if (!bfd_is_abs_section (p->sec)
1097 && bfd_is_abs_section (p->sec->output_section))
1098 {
1099 /* Input section has been discarded, either because
1100 it is a copy of a linkonce section or due to
1101 linker script /DISCARD/, so we'll be discarding
1102 the relocs too. */
1103 }
1104 else if (htab->target_os == is_vxworks
1105 && strcmp (p->sec->output_section->name,
1106 ".tls_vars") == 0)
1107 {
1108 /* Relocations in vxworks .tls_vars sections are
1109 handled specially by the loader. */
1110 }
1111 else if (p->count != 0)
1112 {
1113 srel = elf_section_data (p->sec)->sreloc;
1114 srel->size += p->count * htab->sizeof_reloc;
1115 if ((p->sec->output_section->flags & SEC_READONLY) != 0
1116 && (info->flags & DF_TEXTREL) == 0)
1117 {
1118 info->flags |= DF_TEXTREL;
1119 if (bfd_link_textrel_check (info))
1120 /* xgettext:c-format */
1121 info->callbacks->einfo
1122 (_("%P: %pB: warning: relocation "
1123 "in read-only section `%pA'\n"),
1124 p->sec->owner, p->sec);
1125 }
1126 }
1127 }
1128 }
1129
1130 local_got = elf_local_got_refcounts (ibfd);
1131 if (!local_got)
1132 continue;
1133
1134 symtab_hdr = &elf_symtab_hdr (ibfd);
1135 locsymcount = symtab_hdr->sh_info;
1136 end_local_got = local_got + locsymcount;
1137 local_tls_type = elf_x86_local_got_tls_type (ibfd);
1138 local_tlsdesc_gotent = elf_x86_local_tlsdesc_gotent (ibfd);
1139 s = htab->elf.sgot;
1140 srel = htab->elf.srelgot;
1141 for (; local_got < end_local_got;
1142 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
1143 {
1144 *local_tlsdesc_gotent = (bfd_vma) -1;
1145 if (*local_got > 0)
1146 {
1147 if (GOT_TLS_GDESC_P (*local_tls_type))
1148 {
1149 *local_tlsdesc_gotent = htab->elf.sgotplt->size
1150 - elf_x86_compute_jump_table_size (htab);
1151 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
1152 *local_got = (bfd_vma) -2;
1153 }
1154 if (! GOT_TLS_GDESC_P (*local_tls_type)
1155 || GOT_TLS_GD_P (*local_tls_type))
1156 {
1157 *local_got = s->size;
1158 s->size += htab->got_entry_size;
1159 if (GOT_TLS_GD_P (*local_tls_type)
1160 || *local_tls_type == GOT_TLS_IE_BOTH)
1161 s->size += htab->got_entry_size;
1162 }
1163 if ((bfd_link_pic (info) && *local_tls_type != GOT_ABS)
1164 || GOT_TLS_GD_ANY_P (*local_tls_type)
1165 || (*local_tls_type & GOT_TLS_IE))
1166 {
1167 if (*local_tls_type == GOT_TLS_IE_BOTH)
1168 srel->size += 2 * htab->sizeof_reloc;
1169 else if (GOT_TLS_GD_P (*local_tls_type)
1170 || ! GOT_TLS_GDESC_P (*local_tls_type))
1171 srel->size += htab->sizeof_reloc;
1172 if (GOT_TLS_GDESC_P (*local_tls_type))
1173 {
1174 htab->elf.srelplt->size += htab->sizeof_reloc;
1175 if (bed->target_id == X86_64_ELF_DATA)
1176 htab->tlsdesc_plt = (bfd_vma) -1;
1177 }
1178 }
1179 }
1180 else
1181 *local_got = (bfd_vma) -1;
1182 }
1183 }
1184
1185 if (htab->tls_ld_or_ldm_got.refcount > 0)
1186 {
1187 /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM
1188 or R_X86_64_TLSLD relocs. */
1189 htab->tls_ld_or_ldm_got.offset = htab->elf.sgot->size;
1190 htab->elf.sgot->size += 2 * htab->got_entry_size;
1191 htab->elf.srelgot->size += htab->sizeof_reloc;
1192 }
1193 else
1194 htab->tls_ld_or_ldm_got.offset = -1;
1195
1196 /* Allocate global sym .plt and .got entries, and space for global
1197 sym dynamic relocs. */
1198 elf_link_hash_traverse (&htab->elf, elf_x86_allocate_dynrelocs,
1199 info);
1200
1201 /* Allocate .plt and .got entries, and space for local symbols. */
1202 htab_traverse (htab->loc_hash_table, elf_x86_allocate_local_dynreloc,
1203 info);
1204
1205 /* For every jump slot reserved in the sgotplt, reloc_count is
1206 incremented. However, when we reserve space for TLS descriptors,
1207 it's not incremented, so in order to compute the space reserved
1208 for them, it suffices to multiply the reloc count by the jump
1209 slot size.
1210
1211 PR ld/13302: We start next_irelative_index at the end of .rela.plt
1212 so that R_{386,X86_64}_IRELATIVE entries come last. */
1213 if (htab->elf.srelplt)
1214 {
1215 htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
1216 htab->sgotplt_jump_table_size
1217 = elf_x86_compute_jump_table_size (htab);
1218 htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
1219 }
1220 else if (htab->elf.irelplt)
1221 htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
1222
1223 if (htab->tlsdesc_plt)
1224 {
1225 /* NB: tlsdesc_plt is set only for x86-64. If we're not using
1226 lazy TLS relocations, don't generate the PLT and GOT entries
1227 they require. */
1228 if ((info->flags & DF_BIND_NOW))
1229 htab->tlsdesc_plt = 0;
1230 else
1231 {
1232 htab->tlsdesc_got = htab->elf.sgot->size;
1233 htab->elf.sgot->size += htab->got_entry_size;
1234 /* Reserve room for the initial entry.
1235 FIXME: we could probably do away with it in this case. */
1236 if (htab->elf.splt->size == 0)
1237 htab->elf.splt->size = htab->plt.plt_entry_size;
1238 htab->tlsdesc_plt = htab->elf.splt->size;
1239 htab->elf.splt->size += htab->plt.plt_entry_size;
1240 }
1241 }
1242
1243 if (htab->elf.sgotplt)
1244 {
1245 /* Don't allocate .got.plt section if there are no GOT nor PLT
1246 entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */
1247 if ((htab->elf.hgot == NULL
1248 || !htab->got_referenced)
1249 && (htab->elf.sgotplt->size == bed->got_header_size)
1250 && (htab->elf.splt == NULL
1251 || htab->elf.splt->size == 0)
1252 && (htab->elf.sgot == NULL
1253 || htab->elf.sgot->size == 0)
1254 && (htab->elf.iplt == NULL
1255 || htab->elf.iplt->size == 0)
1256 && (htab->elf.igotplt == NULL
1257 || htab->elf.igotplt->size == 0))
1258 {
1259 htab->elf.sgotplt->size = 0;
1260 /* Solaris requires to keep _GLOBAL_OFFSET_TABLE_ even if it
1261 isn't used. */
1262 if (htab->elf.hgot != NULL && htab->target_os != is_solaris)
1263 {
1264 /* Remove the unused _GLOBAL_OFFSET_TABLE_ from symbol
1265 table. */
1266 htab->elf.hgot->root.type = bfd_link_hash_undefined;
1267 htab->elf.hgot->root.u.undef.abfd
1268 = htab->elf.hgot->root.u.def.section->owner;
1269 htab->elf.hgot->root.linker_def = 0;
1270 htab->elf.hgot->ref_regular = 0;
1271 htab->elf.hgot->def_regular = 0;
1272 }
1273 }
1274 }
1275
1276 if (_bfd_elf_eh_frame_present (info))
1277 {
1278 if (htab->plt_eh_frame != NULL
1279 && htab->elf.splt != NULL
1280 && htab->elf.splt->size != 0
1281 && !bfd_is_abs_section (htab->elf.splt->output_section))
1282 htab->plt_eh_frame->size = htab->plt.eh_frame_plt_size;
1283
1284 if (htab->plt_got_eh_frame != NULL
1285 && htab->plt_got != NULL
1286 && htab->plt_got->size != 0
1287 && !bfd_is_abs_section (htab->plt_got->output_section))
1288 htab->plt_got_eh_frame->size
1289 = htab->non_lazy_plt->eh_frame_plt_size;
1290
1291 /* Unwind info for the second PLT and .plt.got sections are
1292 identical. */
1293 if (htab->plt_second_eh_frame != NULL
1294 && htab->plt_second != NULL
1295 && htab->plt_second->size != 0
1296 && !bfd_is_abs_section (htab->plt_second->output_section))
1297 htab->plt_second_eh_frame->size
1298 = htab->non_lazy_plt->eh_frame_plt_size;
1299 }
1300
1301 /* We now have determined the sizes of the various dynamic sections.
1302 Allocate memory for them. */
1303 relocs = FALSE;
1304 for (s = dynobj->sections; s != NULL; s = s->next)
1305 {
1306 bfd_boolean strip_section = TRUE;
1307
1308 if ((s->flags & SEC_LINKER_CREATED) == 0)
1309 continue;
1310
1311 if (s == htab->elf.splt
1312 || s == htab->elf.sgot)
1313 {
1314 /* Strip this section if we don't need it; see the
1315 comment below. */
1316 /* We'd like to strip these sections if they aren't needed, but if
1317 we've exported dynamic symbols from them we must leave them.
1318 It's too late to tell BFD to get rid of the symbols. */
1319
1320 if (htab->elf.hplt != NULL)
1321 strip_section = FALSE;
1322 }
1323 else if (s == htab->elf.sgotplt
1324 || s == htab->elf.iplt
1325 || s == htab->elf.igotplt
1326 || s == htab->plt_second
1327 || s == htab->plt_got
1328 || s == htab->plt_eh_frame
1329 || s == htab->plt_got_eh_frame
1330 || s == htab->plt_second_eh_frame
1331 || s == htab->elf.sdynbss
1332 || s == htab->elf.sdynrelro)
1333 {
1334 /* Strip these too. */
1335 }
1336 else if (htab->is_reloc_section (bfd_section_name (s)))
1337 {
1338 if (s->size != 0
1339 && s != htab->elf.srelplt
1340 && s != htab->srelplt2)
1341 relocs = TRUE;
1342
1343 /* We use the reloc_count field as a counter if we need
1344 to copy relocs into the output file. */
1345 if (s != htab->elf.srelplt)
1346 s->reloc_count = 0;
1347 }
1348 else
1349 {
1350 /* It's not one of our sections, so don't allocate space. */
1351 continue;
1352 }
1353
1354 if (s->size == 0)
1355 {
1356 /* If we don't need this section, strip it from the
1357 output file. This is mostly to handle .rel.bss and
1358 .rel.plt. We must create both sections in
1359 create_dynamic_sections, because they must be created
1360 before the linker maps input sections to output
1361 sections. The linker does that before
1362 adjust_dynamic_symbol is called, and it is that
1363 function which decides whether anything needs to go
1364 into these sections. */
1365 if (strip_section)
1366 s->flags |= SEC_EXCLUDE;
1367 continue;
1368 }
1369
1370 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1371 continue;
1372
1373 /* NB: Initially, the iplt section has minimal alignment to
1374 avoid moving dot of the following section backwards when
1375 it is empty. Update its section alignment now since it
1376 is non-empty. */
1377 if (s == htab->elf.iplt)
1378 bfd_set_section_alignment (s, htab->plt.iplt_alignment);
1379
1380 /* Allocate memory for the section contents. We use bfd_zalloc
1381 here in case unused entries are not reclaimed before the
1382 section's contents are written out. This should not happen,
1383 but this way if it does, we get a R_386_NONE or R_X86_64_NONE
1384 reloc instead of garbage. */
1385 s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size);
1386 if (s->contents == NULL)
1387 return FALSE;
1388 }
1389
1390 if (htab->plt_eh_frame != NULL
1391 && htab->plt_eh_frame->contents != NULL)
1392 {
1393 memcpy (htab->plt_eh_frame->contents,
1394 htab->plt.eh_frame_plt,
1395 htab->plt_eh_frame->size);
1396 bfd_put_32 (dynobj, htab->elf.splt->size,
1397 htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET);
1398 }
1399
1400 if (htab->plt_got_eh_frame != NULL
1401 && htab->plt_got_eh_frame->contents != NULL)
1402 {
1403 memcpy (htab->plt_got_eh_frame->contents,
1404 htab->non_lazy_plt->eh_frame_plt,
1405 htab->plt_got_eh_frame->size);
1406 bfd_put_32 (dynobj, htab->plt_got->size,
1407 (htab->plt_got_eh_frame->contents
1408 + PLT_FDE_LEN_OFFSET));
1409 }
1410
1411 if (htab->plt_second_eh_frame != NULL
1412 && htab->plt_second_eh_frame->contents != NULL)
1413 {
1414 memcpy (htab->plt_second_eh_frame->contents,
1415 htab->non_lazy_plt->eh_frame_plt,
1416 htab->plt_second_eh_frame->size);
1417 bfd_put_32 (dynobj, htab->plt_second->size,
1418 (htab->plt_second_eh_frame->contents
1419 + PLT_FDE_LEN_OFFSET));
1420 }
1421
1422 if (htab->elf.dynamic_sections_created)
1423 {
1424 /* Add some entries to the .dynamic section. We fill in the
1425 values later, in elf_{i386,x86_64}_finish_dynamic_sections,
1426 but we must add the entries now so that we get the correct
1427 size for the .dynamic section. The DT_DEBUG entry is filled
1428 in by the dynamic linker and used by the debugger. */
1429 #define add_dynamic_entry(TAG, VAL) \
1430 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1431
1432 if (bfd_link_executable (info))
1433 {
1434 if (!add_dynamic_entry (DT_DEBUG, 0))
1435 return FALSE;
1436 }
1437
1438 if (htab->elf.splt->size != 0)
1439 {
1440 /* DT_PLTGOT is used by prelink even if there is no PLT
1441 relocation. */
1442 if (!add_dynamic_entry (DT_PLTGOT, 0))
1443 return FALSE;
1444 }
1445
1446 if (htab->elf.srelplt->size != 0)
1447 {
1448 if (!add_dynamic_entry (DT_PLTRELSZ, 0)
1449 || !add_dynamic_entry (DT_PLTREL, htab->dt_reloc)
1450 || !add_dynamic_entry (DT_JMPREL, 0))
1451 return FALSE;
1452 }
1453
1454 if (htab->tlsdesc_plt
1455 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
1456 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
1457 return FALSE;
1458
1459 if (relocs)
1460 {
1461 if (!add_dynamic_entry (htab->dt_reloc, 0)
1462 || !add_dynamic_entry (htab->dt_reloc_sz, 0)
1463 || !add_dynamic_entry (htab->dt_reloc_ent,
1464 htab->sizeof_reloc))
1465 return FALSE;
1466
1467 /* If any dynamic relocs apply to a read-only section,
1468 then we need a DT_TEXTREL entry. */
1469 if ((info->flags & DF_TEXTREL) == 0)
1470 elf_link_hash_traverse (&htab->elf, maybe_set_textrel, info);
1471
1472 if ((info->flags & DF_TEXTREL) != 0)
1473 {
1474 if (htab->readonly_dynrelocs_against_ifunc)
1475 {
1476 info->callbacks->einfo
1477 (_("%P%X: read-only segment has dynamic IFUNC relocations;"
1478 " recompile with %s\n"),
1479 bfd_link_dll (info) ? "-fPIC" : "-fPIE");
1480 bfd_set_error (bfd_error_bad_value);
1481 return FALSE;
1482 }
1483
1484 if (!add_dynamic_entry (DT_TEXTREL, 0))
1485 return FALSE;
1486 }
1487 }
1488 if (htab->target_os == is_vxworks
1489 && !elf_vxworks_add_dynamic_entries (output_bfd, info))
1490 return FALSE;
1491 }
1492 #undef add_dynamic_entry
1493
1494 return TRUE;
1495 }
1496
1497 /* Finish up the x86 dynamic sections. */
1498
1499 struct elf_x86_link_hash_table *
1500 _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd,
1501 struct bfd_link_info *info)
1502 {
1503 struct elf_x86_link_hash_table *htab;
1504 const struct elf_backend_data *bed;
1505 bfd *dynobj;
1506 asection *sdyn;
1507 bfd_byte *dyncon, *dynconend;
1508 bfd_size_type sizeof_dyn;
1509
1510 bed = get_elf_backend_data (output_bfd);
1511 htab = elf_x86_hash_table (info, bed->target_id);
1512 if (htab == NULL)
1513 return htab;
1514
1515 dynobj = htab->elf.dynobj;
1516 sdyn = bfd_get_linker_section (dynobj, ".dynamic");
1517
1518 /* GOT is always created in setup_gnu_properties. But it may not be
1519 needed. .got.plt section may be needed for static IFUNC. */
1520 if (htab->elf.sgotplt && htab->elf.sgotplt->size > 0)
1521 {
1522 bfd_vma dynamic_addr;
1523
1524 if (bfd_is_abs_section (htab->elf.sgotplt->output_section))
1525 {
1526 _bfd_error_handler
1527 (_("discarded output section: `%pA'"), htab->elf.sgotplt);
1528 return NULL;
1529 }
1530
1531 elf_section_data (htab->elf.sgotplt->output_section)->this_hdr.sh_entsize
1532 = htab->got_entry_size;
1533
1534 dynamic_addr = (sdyn == NULL
1535 ? (bfd_vma) 0
1536 : sdyn->output_section->vma + sdyn->output_offset);
1537
1538 /* Set the first entry in the global offset table to the address
1539 of the dynamic section. Write GOT[1] and GOT[2], needed for
1540 the dynamic linker. */
1541 if (htab->got_entry_size == 8)
1542 {
1543 bfd_put_64 (output_bfd, dynamic_addr,
1544 htab->elf.sgotplt->contents);
1545 bfd_put_64 (output_bfd, (bfd_vma) 0,
1546 htab->elf.sgotplt->contents + 8);
1547 bfd_put_64 (output_bfd, (bfd_vma) 0,
1548 htab->elf.sgotplt->contents + 8*2);
1549 }
1550 else
1551 {
1552 bfd_put_32 (output_bfd, dynamic_addr,
1553 htab->elf.sgotplt->contents);
1554 bfd_put_32 (output_bfd, 0,
1555 htab->elf.sgotplt->contents + 4);
1556 bfd_put_32 (output_bfd, 0,
1557 htab->elf.sgotplt->contents + 4*2);
1558 }
1559 }
1560
1561 if (!htab->elf.dynamic_sections_created)
1562 return htab;
1563
1564 if (sdyn == NULL || htab->elf.sgot == NULL)
1565 abort ();
1566
1567 sizeof_dyn = bed->s->sizeof_dyn;
1568 dyncon = sdyn->contents;
1569 dynconend = sdyn->contents + sdyn->size;
1570 for (; dyncon < dynconend; dyncon += sizeof_dyn)
1571 {
1572 Elf_Internal_Dyn dyn;
1573 asection *s;
1574
1575 (*bed->s->swap_dyn_in) (dynobj, dyncon, &dyn);
1576
1577 switch (dyn.d_tag)
1578 {
1579 default:
1580 if (htab->target_os == is_vxworks
1581 && elf_vxworks_finish_dynamic_entry (output_bfd, &dyn))
1582 break;
1583 continue;
1584
1585 case DT_PLTGOT:
1586 s = htab->elf.sgotplt;
1587 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
1588 break;
1589
1590 case DT_JMPREL:
1591 dyn.d_un.d_ptr = htab->elf.srelplt->output_section->vma;
1592 break;
1593
1594 case DT_PLTRELSZ:
1595 s = htab->elf.srelplt->output_section;
1596 dyn.d_un.d_val = s->size;
1597 break;
1598
1599 case DT_TLSDESC_PLT:
1600 s = htab->elf.splt;
1601 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
1602 + htab->tlsdesc_plt;
1603 break;
1604
1605 case DT_TLSDESC_GOT:
1606 s = htab->elf.sgot;
1607 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
1608 + htab->tlsdesc_got;
1609 break;
1610 }
1611
1612 (*bed->s->swap_dyn_out) (output_bfd, &dyn, dyncon);
1613 }
1614
1615 if (htab->plt_got != NULL && htab->plt_got->size > 0)
1616 elf_section_data (htab->plt_got->output_section)
1617 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size;
1618
1619 if (htab->plt_second != NULL && htab->plt_second->size > 0)
1620 elf_section_data (htab->plt_second->output_section)
1621 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size;
1622
1623 /* Adjust .eh_frame for .plt section. */
1624 if (htab->plt_eh_frame != NULL
1625 && htab->plt_eh_frame->contents != NULL)
1626 {
1627 if (htab->elf.splt != NULL
1628 && htab->elf.splt->size != 0
1629 && (htab->elf.splt->flags & SEC_EXCLUDE) == 0
1630 && htab->elf.splt->output_section != NULL
1631 && htab->plt_eh_frame->output_section != NULL)
1632 {
1633 bfd_vma plt_start = htab->elf.splt->output_section->vma;
1634 bfd_vma eh_frame_start = htab->plt_eh_frame->output_section->vma
1635 + htab->plt_eh_frame->output_offset
1636 + PLT_FDE_START_OFFSET;
1637 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1638 htab->plt_eh_frame->contents
1639 + PLT_FDE_START_OFFSET);
1640 }
1641
1642 if (htab->plt_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
1643 {
1644 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1645 htab->plt_eh_frame,
1646 htab->plt_eh_frame->contents))
1647 return NULL;
1648 }
1649 }
1650
1651 /* Adjust .eh_frame for .plt.got section. */
1652 if (htab->plt_got_eh_frame != NULL
1653 && htab->plt_got_eh_frame->contents != NULL)
1654 {
1655 if (htab->plt_got != NULL
1656 && htab->plt_got->size != 0
1657 && (htab->plt_got->flags & SEC_EXCLUDE) == 0
1658 && htab->plt_got->output_section != NULL
1659 && htab->plt_got_eh_frame->output_section != NULL)
1660 {
1661 bfd_vma plt_start = htab->plt_got->output_section->vma;
1662 bfd_vma eh_frame_start = htab->plt_got_eh_frame->output_section->vma
1663 + htab->plt_got_eh_frame->output_offset
1664 + PLT_FDE_START_OFFSET;
1665 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1666 htab->plt_got_eh_frame->contents
1667 + PLT_FDE_START_OFFSET);
1668 }
1669 if (htab->plt_got_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
1670 {
1671 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1672 htab->plt_got_eh_frame,
1673 htab->plt_got_eh_frame->contents))
1674 return NULL;
1675 }
1676 }
1677
1678 /* Adjust .eh_frame for the second PLT section. */
1679 if (htab->plt_second_eh_frame != NULL
1680 && htab->plt_second_eh_frame->contents != NULL)
1681 {
1682 if (htab->plt_second != NULL
1683 && htab->plt_second->size != 0
1684 && (htab->plt_second->flags & SEC_EXCLUDE) == 0
1685 && htab->plt_second->output_section != NULL
1686 && htab->plt_second_eh_frame->output_section != NULL)
1687 {
1688 bfd_vma plt_start = htab->plt_second->output_section->vma;
1689 bfd_vma eh_frame_start
1690 = (htab->plt_second_eh_frame->output_section->vma
1691 + htab->plt_second_eh_frame->output_offset
1692 + PLT_FDE_START_OFFSET);
1693 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1694 htab->plt_second_eh_frame->contents
1695 + PLT_FDE_START_OFFSET);
1696 }
1697 if (htab->plt_second_eh_frame->sec_info_type
1698 == SEC_INFO_TYPE_EH_FRAME)
1699 {
1700 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1701 htab->plt_second_eh_frame,
1702 htab->plt_second_eh_frame->contents))
1703 return NULL;
1704 }
1705 }
1706
1707 if (htab->elf.sgot && htab->elf.sgot->size > 0)
1708 elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize
1709 = htab->got_entry_size;
1710
1711 return htab;
1712 }
1713
1714
1715 bfd_boolean
1716 _bfd_x86_elf_always_size_sections (bfd *output_bfd,
1717 struct bfd_link_info *info)
1718 {
1719 asection *tls_sec = elf_hash_table (info)->tls_sec;
1720
1721 if (tls_sec)
1722 {
1723 struct elf_link_hash_entry *tlsbase;
1724
1725 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1726 "_TLS_MODULE_BASE_",
1727 FALSE, FALSE, FALSE);
1728
1729 if (tlsbase && tlsbase->type == STT_TLS)
1730 {
1731 struct elf_x86_link_hash_table *htab;
1732 struct bfd_link_hash_entry *bh = NULL;
1733 const struct elf_backend_data *bed
1734 = get_elf_backend_data (output_bfd);
1735
1736 htab = elf_x86_hash_table (info, bed->target_id);
1737 if (htab == NULL)
1738 return FALSE;
1739
1740 if (!(_bfd_generic_link_add_one_symbol
1741 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1742 tls_sec, 0, NULL, FALSE,
1743 bed->collect, &bh)))
1744 return FALSE;
1745
1746 htab->tls_module_base = bh;
1747
1748 tlsbase = (struct elf_link_hash_entry *)bh;
1749 tlsbase->def_regular = 1;
1750 tlsbase->other = STV_HIDDEN;
1751 tlsbase->root.linker_def = 1;
1752 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
1753 }
1754 }
1755
1756 return TRUE;
1757 }
1758
1759 void
1760 _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h,
1761 const Elf_Internal_Sym *isym,
1762 bfd_boolean definition,
1763 bfd_boolean dynamic ATTRIBUTE_UNUSED)
1764 {
1765 if (definition)
1766 {
1767 struct elf_x86_link_hash_entry *eh
1768 = (struct elf_x86_link_hash_entry *) h;
1769 eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other)
1770 == STV_PROTECTED);
1771 }
1772 }
1773
1774 /* Copy the extra info we tack onto an elf_link_hash_entry. */
1775
1776 void
1777 _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info,
1778 struct elf_link_hash_entry *dir,
1779 struct elf_link_hash_entry *ind)
1780 {
1781 struct elf_x86_link_hash_entry *edir, *eind;
1782
1783 edir = (struct elf_x86_link_hash_entry *) dir;
1784 eind = (struct elf_x86_link_hash_entry *) ind;
1785
1786 if (ind->dyn_relocs != NULL)
1787 {
1788 if (dir->dyn_relocs != NULL)
1789 {
1790 struct elf_dyn_relocs **pp;
1791 struct elf_dyn_relocs *p;
1792
1793 /* Add reloc counts against the indirect sym to the direct sym
1794 list. Merge any entries against the same section. */
1795 for (pp = &ind->dyn_relocs; (p = *pp) != NULL; )
1796 {
1797 struct elf_dyn_relocs *q;
1798
1799 for (q = dir->dyn_relocs; q != NULL; q = q->next)
1800 if (q->sec == p->sec)
1801 {
1802 q->pc_count += p->pc_count;
1803 q->count += p->count;
1804 *pp = p->next;
1805 break;
1806 }
1807 if (q == NULL)
1808 pp = &p->next;
1809 }
1810 *pp = dir->dyn_relocs;
1811 }
1812
1813 dir->dyn_relocs = ind->dyn_relocs;
1814 ind->dyn_relocs = NULL;
1815 }
1816
1817 if (ind->root.type == bfd_link_hash_indirect
1818 && dir->got.refcount <= 0)
1819 {
1820 edir->tls_type = eind->tls_type;
1821 eind->tls_type = GOT_UNKNOWN;
1822 }
1823
1824 /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will
1825 generate a R_386_COPY reloc. */
1826 edir->gotoff_ref |= eind->gotoff_ref;
1827
1828 edir->zero_undefweak |= eind->zero_undefweak;
1829
1830 if (ELIMINATE_COPY_RELOCS
1831 && ind->root.type != bfd_link_hash_indirect
1832 && dir->dynamic_adjusted)
1833 {
1834 /* If called to transfer flags for a weakdef during processing
1835 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
1836 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
1837 if (dir->versioned != versioned_hidden)
1838 dir->ref_dynamic |= ind->ref_dynamic;
1839 dir->ref_regular |= ind->ref_regular;
1840 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
1841 dir->needs_plt |= ind->needs_plt;
1842 dir->pointer_equality_needed |= ind->pointer_equality_needed;
1843 }
1844 else
1845 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
1846 }
1847
1848 /* Remove undefined weak symbol from the dynamic symbol table if it
1849 is resolved to 0. */
1850
1851 bfd_boolean
1852 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
1853 struct elf_link_hash_entry *h)
1854 {
1855 if (h->dynindx != -1
1856 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h)))
1857 {
1858 h->dynindx = -1;
1859 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
1860 h->dynstr_index);
1861 }
1862 return TRUE;
1863 }
1864
1865 /* Change the STT_GNU_IFUNC symbol defined in position-dependent
1866 executable into the normal function symbol and set its address
1867 to its PLT entry, which should be resolved by R_*_IRELATIVE at
1868 run-time. */
1869
1870 void
1871 _bfd_x86_elf_link_fixup_ifunc_symbol (struct bfd_link_info *info,
1872 struct elf_x86_link_hash_table *htab,
1873 struct elf_link_hash_entry *h,
1874 Elf_Internal_Sym *sym)
1875 {
1876 if (bfd_link_pde (info)
1877 && h->def_regular
1878 && h->dynindx != -1
1879 && h->plt.offset != (bfd_vma) -1
1880 && h->type == STT_GNU_IFUNC
1881 && h->pointer_equality_needed)
1882 {
1883 asection *plt_s;
1884 bfd_vma plt_offset;
1885 bfd *output_bfd = info->output_bfd;
1886
1887 if (htab->plt_second)
1888 {
1889 struct elf_x86_link_hash_entry *eh
1890 = (struct elf_x86_link_hash_entry *) h;
1891
1892 plt_s = htab->plt_second;
1893 plt_offset = eh->plt_second.offset;
1894 }
1895 else
1896 {
1897 plt_s = htab->elf.splt;
1898 plt_offset = h->plt.offset;
1899 }
1900
1901 sym->st_size = 0;
1902 sym->st_info = ELF_ST_INFO (ELF_ST_BIND (sym->st_info), STT_FUNC);
1903 sym->st_shndx
1904 = _bfd_elf_section_from_bfd_section (output_bfd,
1905 plt_s->output_section);
1906 sym->st_value = (plt_s->output_section->vma
1907 + plt_s->output_offset + plt_offset);
1908 }
1909 }
1910
1911 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1912
1913 bfd_boolean
1914 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1915 {
1916 if (h->plt.offset != (bfd_vma) -1
1917 && !h->def_regular
1918 && !h->pointer_equality_needed)
1919 return FALSE;
1920
1921 return _bfd_elf_hash_symbol (h);
1922 }
1923
1924 /* Adjust a symbol defined by a dynamic object and referenced by a
1925 regular object. The current definition is in some section of the
1926 dynamic object, but we're not including those sections. We have to
1927 change the definition to something the rest of the link can
1928 understand. */
1929
1930 bfd_boolean
1931 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1932 struct elf_link_hash_entry *h)
1933 {
1934 struct elf_x86_link_hash_table *htab;
1935 asection *s, *srel;
1936 struct elf_x86_link_hash_entry *eh;
1937 struct elf_dyn_relocs *p;
1938 const struct elf_backend_data *bed
1939 = get_elf_backend_data (info->output_bfd);
1940
1941 /* STT_GNU_IFUNC symbol must go through PLT. */
1942 if (h->type == STT_GNU_IFUNC)
1943 {
1944 /* All local STT_GNU_IFUNC references must be treate as local
1945 calls via local PLT. */
1946 if (h->ref_regular
1947 && SYMBOL_CALLS_LOCAL (info, h))
1948 {
1949 bfd_size_type pc_count = 0, count = 0;
1950 struct elf_dyn_relocs **pp;
1951
1952 eh = (struct elf_x86_link_hash_entry *) h;
1953 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
1954 {
1955 pc_count += p->pc_count;
1956 p->count -= p->pc_count;
1957 p->pc_count = 0;
1958 count += p->count;
1959 if (p->count == 0)
1960 *pp = p->next;
1961 else
1962 pp = &p->next;
1963 }
1964
1965 if (pc_count || count)
1966 {
1967 h->non_got_ref = 1;
1968 if (pc_count)
1969 {
1970 /* Increment PLT reference count only for PC-relative
1971 references. */
1972 h->needs_plt = 1;
1973 if (h->plt.refcount <= 0)
1974 h->plt.refcount = 1;
1975 else
1976 h->plt.refcount += 1;
1977 }
1978 }
1979 }
1980
1981 if (h->plt.refcount <= 0)
1982 {
1983 h->plt.offset = (bfd_vma) -1;
1984 h->needs_plt = 0;
1985 }
1986 return TRUE;
1987 }
1988
1989 /* If this is a function, put it in the procedure linkage table. We
1990 will fill in the contents of the procedure linkage table later,
1991 when we know the address of the .got section. */
1992 if (h->type == STT_FUNC
1993 || h->needs_plt)
1994 {
1995 if (h->plt.refcount <= 0
1996 || SYMBOL_CALLS_LOCAL (info, h)
1997 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1998 && h->root.type == bfd_link_hash_undefweak))
1999 {
2000 /* This case can occur if we saw a PLT32 reloc in an input
2001 file, but the symbol was never referred to by a dynamic
2002 object, or if all references were garbage collected. In
2003 such a case, we don't actually need to build a procedure
2004 linkage table, and we can just do a PC32 reloc instead. */
2005 h->plt.offset = (bfd_vma) -1;
2006 h->needs_plt = 0;
2007 }
2008
2009 return TRUE;
2010 }
2011 else
2012 /* It's possible that we incorrectly decided a .plt reloc was needed
2013 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
2014 check_relocs. We can't decide accurately between function and
2015 non-function syms in check-relocs; Objects loaded later in
2016 the link may change h->type. So fix it now. */
2017 h->plt.offset = (bfd_vma) -1;
2018
2019 eh = (struct elf_x86_link_hash_entry *) h;
2020
2021 /* If this is a weak symbol, and there is a real definition, the
2022 processor independent code will have arranged for us to see the
2023 real definition first, and we can just use the same value. */
2024 if (h->is_weakalias)
2025 {
2026 struct elf_link_hash_entry *def = weakdef (h);
2027 BFD_ASSERT (def->root.type == bfd_link_hash_defined);
2028 h->root.u.def.section = def->root.u.def.section;
2029 h->root.u.def.value = def->root.u.def.value;
2030 if (ELIMINATE_COPY_RELOCS
2031 || info->nocopyreloc
2032 || SYMBOL_NO_COPYRELOC (info, eh))
2033 {
2034 /* NB: needs_copy is always 0 for i386. */
2035 h->non_got_ref = def->non_got_ref;
2036 eh->needs_copy = def->needs_copy;
2037 }
2038 return TRUE;
2039 }
2040
2041 /* This is a reference to a symbol defined by a dynamic object which
2042 is not a function. */
2043
2044 /* If we are creating a shared library, we must presume that the
2045 only references to the symbol are via the global offset table.
2046 For such cases we need not do anything here; the relocations will
2047 be handled correctly by relocate_section. */
2048 if (!bfd_link_executable (info))
2049 return TRUE;
2050
2051 /* If there are no references to this symbol that do not use the
2052 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
2053 reloc. NB: gotoff_ref is always 0 for x86-64. */
2054 if (!h->non_got_ref && !eh->gotoff_ref)
2055 return TRUE;
2056
2057 /* If -z nocopyreloc was given, we won't generate them either. */
2058 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
2059 {
2060 h->non_got_ref = 0;
2061 return TRUE;
2062 }
2063
2064 htab = elf_x86_hash_table (info, bed->target_id);
2065 if (htab == NULL)
2066 return FALSE;
2067
2068 /* If there aren't any dynamic relocs in read-only sections nor
2069 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
2070 avoid the copy reloc. This doesn't work on VxWorks, where we can
2071 not have dynamic relocations (other than copy and jump slot
2072 relocations) in an executable. */
2073 if (ELIMINATE_COPY_RELOCS
2074 && (bed->target_id == X86_64_ELF_DATA
2075 || (!eh->gotoff_ref
2076 && htab->target_os != is_vxworks)))
2077 {
2078 /* If we don't find any dynamic relocs in read-only sections,
2079 then we'll be keeping the dynamic relocs and avoiding the copy
2080 reloc. */
2081 if (!readonly_dynrelocs (h))
2082 {
2083 h->non_got_ref = 0;
2084 return TRUE;
2085 }
2086 }
2087
2088 /* We must allocate the symbol in our .dynbss section, which will
2089 become part of the .bss section of the executable. There will be
2090 an entry for this symbol in the .dynsym section. The dynamic
2091 object will contain position independent code, so all references
2092 from the dynamic object to this symbol will go through the global
2093 offset table. The dynamic linker will use the .dynsym entry to
2094 determine the address it must put in the global offset table, so
2095 both the dynamic object and the regular object will refer to the
2096 same memory location for the variable. */
2097
2098 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
2099 dynamic linker to copy the initial value out of the dynamic object
2100 and into the runtime process image. */
2101 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
2102 {
2103 s = htab->elf.sdynrelro;
2104 srel = htab->elf.sreldynrelro;
2105 }
2106 else
2107 {
2108 s = htab->elf.sdynbss;
2109 srel = htab->elf.srelbss;
2110 }
2111 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
2112 {
2113 srel->size += htab->sizeof_reloc;
2114 h->needs_copy = 1;
2115 }
2116
2117 return _bfd_elf_adjust_dynamic_copy (info, h, s);
2118 }
2119
2120 void
2121 _bfd_x86_elf_hide_symbol (struct bfd_link_info *info,
2122 struct elf_link_hash_entry *h,
2123 bfd_boolean force_local)
2124 {
2125 if (h->root.type == bfd_link_hash_undefweak
2126 && info->nointerp
2127 && bfd_link_pie (info))
2128 {
2129 /* When there is no dynamic interpreter in PIE, make the undefined
2130 weak symbol dynamic so that PC relative branch to the undefined
2131 weak symbol will land to address 0. */
2132 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
2133 if (h->plt.refcount > 0
2134 || eh->plt_got.refcount > 0)
2135 return;
2136 }
2137
2138 _bfd_elf_link_hash_hide_symbol (info, h, force_local);
2139 }
2140
2141 /* Return TRUE if a symbol is referenced locally. It is similar to
2142 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
2143 works in check_relocs. */
2144
2145 bfd_boolean
2146 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
2147 struct elf_link_hash_entry *h)
2148 {
2149 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
2150 struct elf_x86_link_hash_table *htab
2151 = (struct elf_x86_link_hash_table *) info->hash;
2152
2153 if (eh->local_ref > 1)
2154 return TRUE;
2155
2156 if (eh->local_ref == 1)
2157 return FALSE;
2158
2159 /* Unversioned symbols defined in regular objects can be forced local
2160 by linker version script. A weak undefined symbol is forced local
2161 if
2162 1. It has non-default visibility. Or
2163 2. When building executable, there is no dynamic linker. Or
2164 3. or "-z nodynamic-undefined-weak" is used.
2165 */
2166 if (SYMBOL_REFERENCES_LOCAL (info, h)
2167 || (h->root.type == bfd_link_hash_undefweak
2168 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
2169 || (bfd_link_executable (info)
2170 && htab->interp == NULL)
2171 || info->dynamic_undefined_weak == 0))
2172 || ((h->def_regular || ELF_COMMON_DEF_P (h))
2173 && info->version_info != NULL
2174 && _bfd_elf_link_hide_sym_by_version (info, h)))
2175 {
2176 eh->local_ref = 2;
2177 return TRUE;
2178 }
2179
2180 eh->local_ref = 1;
2181 return FALSE;
2182 }
2183
2184 /* Return the section that should be marked against GC for a given
2185 relocation. */
2186
2187 asection *
2188 _bfd_x86_elf_gc_mark_hook (asection *sec,
2189 struct bfd_link_info *info,
2190 Elf_Internal_Rela *rel,
2191 struct elf_link_hash_entry *h,
2192 Elf_Internal_Sym *sym)
2193 {
2194 /* Compiler should optimize this out. */
2195 if (((unsigned int) R_X86_64_GNU_VTINHERIT
2196 != (unsigned int) R_386_GNU_VTINHERIT)
2197 || ((unsigned int) R_X86_64_GNU_VTENTRY
2198 != (unsigned int) R_386_GNU_VTENTRY))
2199 abort ();
2200
2201 if (h != NULL)
2202 switch (ELF32_R_TYPE (rel->r_info))
2203 {
2204 case R_X86_64_GNU_VTINHERIT:
2205 case R_X86_64_GNU_VTENTRY:
2206 return NULL;
2207 }
2208
2209 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
2210 }
2211
2212 static bfd_vma
2213 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
2214 bfd_vma off,
2215 bfd_vma offset ATTRIBUTE_UNUSED,
2216 bfd_vma got_addr)
2217 {
2218 return got_addr + off;
2219 }
2220
2221 static bfd_vma
2222 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
2223 bfd_vma off,
2224 bfd_vma offset,
2225 bfd_vma got_addr ATTRIBUTE_UNUSED)
2226 {
2227 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
2228 }
2229
2230 static bfd_boolean
2231 elf_i386_valid_plt_reloc_p (unsigned int type)
2232 {
2233 return (type == R_386_JUMP_SLOT
2234 || type == R_386_GLOB_DAT
2235 || type == R_386_IRELATIVE);
2236 }
2237
2238 static bfd_boolean
2239 elf_x86_64_valid_plt_reloc_p (unsigned int type)
2240 {
2241 return (type == R_X86_64_JUMP_SLOT
2242 || type == R_X86_64_GLOB_DAT
2243 || type == R_X86_64_IRELATIVE);
2244 }
2245
2246 long
2247 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
2248 long count,
2249 long relsize,
2250 bfd_vma got_addr,
2251 struct elf_x86_plt plts[],
2252 asymbol **dynsyms,
2253 asymbol **ret)
2254 {
2255 long size, i, n, len;
2256 int j;
2257 unsigned int plt_got_offset, plt_entry_size;
2258 asymbol *s;
2259 bfd_byte *plt_contents;
2260 long dynrelcount;
2261 arelent **dynrelbuf, *p;
2262 char *names;
2263 const struct elf_backend_data *bed;
2264 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
2265 bfd_vma);
2266 bfd_boolean (*valid_plt_reloc_p) (unsigned int);
2267
2268 dynrelbuf = NULL;
2269 if (count == 0)
2270 goto bad_return;
2271
2272 dynrelbuf = (arelent **) bfd_malloc (relsize);
2273 if (dynrelbuf == NULL)
2274 goto bad_return;
2275
2276 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
2277 dynsyms);
2278 if (dynrelcount <= 0)
2279 goto bad_return;
2280
2281 /* Sort the relocs by address. */
2282 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
2283 _bfd_x86_elf_compare_relocs);
2284
2285 size = count * sizeof (asymbol);
2286
2287 /* Allocate space for @plt suffixes. */
2288 n = 0;
2289 for (i = 0; i < dynrelcount; i++)
2290 {
2291 p = dynrelbuf[i];
2292 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
2293 if (p->addend != 0)
2294 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
2295 }
2296
2297 s = *ret = (asymbol *) bfd_zmalloc (size);
2298 if (s == NULL)
2299 goto bad_return;
2300
2301 bed = get_elf_backend_data (abfd);
2302
2303 if (bed->target_id == X86_64_ELF_DATA)
2304 {
2305 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
2306 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
2307 }
2308 else
2309 {
2310 get_plt_got_vma = elf_i386_get_plt_got_vma;
2311 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
2312 if (got_addr)
2313 {
2314 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
2315 address. */
2316 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
2317 if (sec != NULL)
2318 got_addr = sec->vma;
2319 else
2320 {
2321 sec = bfd_get_section_by_name (abfd, ".got");
2322 if (sec != NULL)
2323 got_addr = sec->vma;
2324 }
2325
2326 if (got_addr == (bfd_vma) -1)
2327 goto bad_return;
2328 }
2329 }
2330
2331 /* Check for each PLT section. */
2332 names = (char *) (s + count);
2333 size = 0;
2334 n = 0;
2335 for (j = 0; plts[j].name != NULL; j++)
2336 if ((plt_contents = plts[j].contents) != NULL)
2337 {
2338 long k;
2339 bfd_vma offset;
2340 asection *plt;
2341 struct elf_x86_plt *plt_p = &plts[j];
2342
2343 plt_got_offset = plt_p->plt_got_offset;
2344 plt_entry_size = plt_p->plt_entry_size;
2345
2346 plt = plt_p->sec;
2347
2348 if ((plt_p->type & plt_lazy))
2349 {
2350 /* Skip PLT0 in lazy PLT. */
2351 k = 1;
2352 offset = plt_entry_size;
2353 }
2354 else
2355 {
2356 k = 0;
2357 offset = 0;
2358 }
2359
2360 /* Check each PLT entry against dynamic relocations. */
2361 for (; k < plt_p->count; k++)
2362 {
2363 int off;
2364 bfd_vma got_vma;
2365 long min, max, mid;
2366
2367 /* Get the GOT offset for i386 or the PC-relative offset
2368 for x86-64, a signed 32-bit integer. */
2369 off = H_GET_32 (abfd, (plt_contents + offset
2370 + plt_got_offset));
2371 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
2372
2373 /* Binary search. */
2374 p = dynrelbuf[0];
2375 min = 0;
2376 max = dynrelcount;
2377 while ((min + 1) < max)
2378 {
2379 arelent *r;
2380
2381 mid = (min + max) / 2;
2382 r = dynrelbuf[mid];
2383 if (got_vma > r->address)
2384 min = mid;
2385 else if (got_vma < r->address)
2386 max = mid;
2387 else
2388 {
2389 p = r;
2390 break;
2391 }
2392 }
2393
2394 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
2395 if (got_vma == p->address
2396 && p->howto != NULL
2397 && valid_plt_reloc_p (p->howto->type))
2398 {
2399 *s = **p->sym_ptr_ptr;
2400 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
2401 set. Since we are defining a symbol, ensure one
2402 of them is set. */
2403 if ((s->flags & BSF_LOCAL) == 0)
2404 s->flags |= BSF_GLOBAL;
2405 s->flags |= BSF_SYNTHETIC;
2406 /* This is no longer a section symbol. */
2407 s->flags &= ~BSF_SECTION_SYM;
2408 s->section = plt;
2409 s->the_bfd = plt->owner;
2410 s->value = offset;
2411 s->udata.p = NULL;
2412 s->name = names;
2413 len = strlen ((*p->sym_ptr_ptr)->name);
2414 memcpy (names, (*p->sym_ptr_ptr)->name, len);
2415 names += len;
2416 if (p->addend != 0)
2417 {
2418 char buf[30], *a;
2419
2420 memcpy (names, "+0x", sizeof ("+0x") - 1);
2421 names += sizeof ("+0x") - 1;
2422 bfd_sprintf_vma (abfd, buf, p->addend);
2423 for (a = buf; *a == '0'; ++a)
2424 ;
2425 size = strlen (a);
2426 memcpy (names, a, size);
2427 names += size;
2428 }
2429 memcpy (names, "@plt", sizeof ("@plt"));
2430 names += sizeof ("@plt");
2431 n++;
2432 s++;
2433 /* There should be only one entry in PLT for a given
2434 symbol. Set howto to NULL after processing a PLT
2435 entry to guard against corrupted PLT. */
2436 p->howto = NULL;
2437 }
2438 offset += plt_entry_size;
2439 }
2440 }
2441
2442 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
2443 if (n == 0)
2444 {
2445 bad_return:
2446 count = -1;
2447 }
2448 else
2449 count = n;
2450
2451 for (j = 0; plts[j].name != NULL; j++)
2452 free (plts[j].contents);
2453
2454 free (dynrelbuf);
2455
2456 return count;
2457 }
2458
2459 /* Parse x86 GNU properties. */
2460
2461 enum elf_property_kind
2462 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
2463 bfd_byte *ptr, unsigned int datasz)
2464 {
2465 elf_property *prop;
2466
2467 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2468 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2469 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
2470 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2471 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
2472 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
2473 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2474 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2475 {
2476 if (datasz != 4)
2477 {
2478 _bfd_error_handler
2479 (_("error: %pB: <corrupt x86 property (0x%x) size: 0x%x>"),
2480 abfd, type, datasz);
2481 return property_corrupt;
2482 }
2483 prop = _bfd_elf_get_property (abfd, type, datasz);
2484 prop->u.number |= bfd_h_get_32 (abfd, ptr);
2485 prop->pr_kind = property_number;
2486 return property_number;
2487 }
2488
2489 return property_ignored;
2490 }
2491
2492 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2493 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2494 should be merged with ABFD. */
2495
2496 bfd_boolean
2497 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2498 bfd *abfd ATTRIBUTE_UNUSED,
2499 bfd *bbfd ATTRIBUTE_UNUSED,
2500 elf_property *aprop,
2501 elf_property *bprop)
2502 {
2503 unsigned int number, features;
2504 bfd_boolean updated = FALSE;
2505 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2506
2507 if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2508 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2509 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2510 {
2511 if (aprop == NULL || bprop == NULL)
2512 {
2513 /* Only one of APROP and BPROP can be NULL. */
2514 if (aprop != NULL)
2515 {
2516 /* Remove this property since the other input file doesn't
2517 have it. */
2518 aprop->pr_kind = property_remove;
2519 updated = TRUE;
2520 }
2521 }
2522 else
2523 {
2524 number = aprop->u.number;
2525 aprop->u.number = number | bprop->u.number;
2526 updated = number != (unsigned int) aprop->u.number;
2527 }
2528 return updated;
2529 }
2530 else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2531 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_LO
2532 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_HI))
2533 {
2534 if (aprop != NULL && bprop != NULL)
2535 {
2536 number = aprop->u.number;
2537 aprop->u.number = number | bprop->u.number;
2538 /* Remove the property if all bits are empty. */
2539 if (aprop->u.number == 0)
2540 {
2541 aprop->pr_kind = property_remove;
2542 updated = TRUE;
2543 }
2544 else
2545 updated = number != (unsigned int) aprop->u.number;
2546 }
2547 else
2548 {
2549 /* Only one of APROP and BPROP can be NULL. */
2550 if (aprop != NULL)
2551 {
2552 if (aprop->u.number == 0)
2553 {
2554 /* Remove APROP if all bits are empty. */
2555 aprop->pr_kind = property_remove;
2556 updated = TRUE;
2557 }
2558 }
2559 else
2560 {
2561 /* Return TRUE if APROP is NULL and all bits of BPROP
2562 aren't empty to indicate that BPROP should be added
2563 to ABFD. */
2564 updated = bprop->u.number != 0;
2565 }
2566 }
2567 return updated;
2568 }
2569 else if (pr_type >= GNU_PROPERTY_X86_UINT32_AND_LO
2570 && pr_type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2571 {
2572 /* Only one of APROP and BPROP can be NULL:
2573 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2574 2. If APROP is NULL, remove x86 feature.
2575 3. Otherwise, do nothing.
2576 */
2577 const struct elf_backend_data *bed
2578 = get_elf_backend_data (info->output_bfd);
2579 struct elf_x86_link_hash_table *htab
2580 = elf_x86_hash_table (info, bed->target_id);
2581 if (!htab)
2582 abort ();
2583 if (aprop != NULL && bprop != NULL)
2584 {
2585 features = 0;
2586 if (htab->params->ibt)
2587 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2588 if (htab->params->shstk)
2589 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2590 number = aprop->u.number;
2591 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2592 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2593 aprop->u.number = (number & bprop->u.number) | features;
2594 updated = number != (unsigned int) aprop->u.number;
2595 /* Remove the property if all feature bits are cleared. */
2596 if (aprop->u.number == 0)
2597 aprop->pr_kind = property_remove;
2598 }
2599 else
2600 {
2601 /* There should be no AND properties since some input doesn't
2602 have them. Set IBT and SHSTK properties for -z ibt and -z
2603 shstk if needed. */
2604 features = 0;
2605 if (htab->params->ibt)
2606 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2607 if (htab->params->shstk)
2608 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2609 if (features)
2610 {
2611 if (aprop != NULL)
2612 {
2613 updated = features != (unsigned int) aprop->u.number;
2614 aprop->u.number = features;
2615 }
2616 else
2617 {
2618 updated = TRUE;
2619 bprop->u.number = features;
2620 }
2621 }
2622 else if (aprop != NULL)
2623 {
2624 aprop->pr_kind = property_remove;
2625 updated = TRUE;
2626 }
2627 }
2628 return updated;
2629 }
2630 else
2631 {
2632 /* Never should happen. */
2633 abort ();
2634 }
2635
2636 return updated;
2637 }
2638
2639 /* Set up x86 GNU properties. Return the first relocatable ELF input
2640 with GNU properties if found. Otherwise, return NULL. */
2641
2642 bfd *
2643 _bfd_x86_elf_link_setup_gnu_properties
2644 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2645 {
2646 bfd_boolean normal_target;
2647 bfd_boolean lazy_plt;
2648 asection *sec, *pltsec;
2649 bfd *dynobj;
2650 bfd_boolean use_ibt_plt;
2651 unsigned int plt_alignment, features;
2652 struct elf_x86_link_hash_table *htab;
2653 bfd *pbfd;
2654 bfd *ebfd = NULL;
2655 elf_property *prop;
2656 const struct elf_backend_data *bed;
2657 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2658 unsigned int got_align;
2659
2660 /* Find a normal input file with GNU property note. */
2661 for (pbfd = info->input_bfds;
2662 pbfd != NULL;
2663 pbfd = pbfd->link.next)
2664 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2665 && bfd_count_sections (pbfd) != 0)
2666 {
2667 ebfd = pbfd;
2668
2669 if (elf_properties (pbfd) != NULL)
2670 break;
2671 }
2672
2673 bed = get_elf_backend_data (info->output_bfd);
2674
2675 htab = elf_x86_hash_table (info, bed->target_id);
2676 if (htab == NULL)
2677 return pbfd;
2678
2679 features = 0;
2680 if (htab->params->ibt)
2681 {
2682 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2683 htab->params->cet_report &= ~cet_report_ibt;
2684 }
2685 if (htab->params->shstk)
2686 {
2687 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2688 htab->params->cet_report &= ~cet_report_shstk;
2689 }
2690 if (!(htab->params->cet_report & (cet_report_ibt | cet_report_shstk)))
2691 htab->params->cet_report = cet_report_none;
2692
2693 if (ebfd != NULL)
2694 {
2695 prop = NULL;
2696 if (features)
2697 {
2698 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
2699 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2700 prop = _bfd_elf_get_property (ebfd,
2701 GNU_PROPERTY_X86_FEATURE_1_AND,
2702 4);
2703 prop->u.number |= features;
2704 prop->pr_kind = property_number;
2705 }
2706
2707 /* Create the GNU property note section if needed. */
2708 if (prop != NULL && pbfd == NULL)
2709 {
2710 sec = bfd_make_section_with_flags (ebfd,
2711 NOTE_GNU_PROPERTY_SECTION_NAME,
2712 (SEC_ALLOC
2713 | SEC_LOAD
2714 | SEC_IN_MEMORY
2715 | SEC_READONLY
2716 | SEC_HAS_CONTENTS
2717 | SEC_DATA));
2718 if (sec == NULL)
2719 info->callbacks->einfo (_("%F%P: failed to create GNU property section\n"));
2720
2721 if (!bfd_set_section_alignment (sec, class_align))
2722 {
2723 error_alignment:
2724 info->callbacks->einfo (_("%F%pA: failed to align section\n"),
2725 sec);
2726 }
2727
2728 elf_section_type (sec) = SHT_NOTE;
2729 }
2730 }
2731
2732 if (htab->params->cet_report)
2733 {
2734 /* Report missing IBT and SHSTK properties. */
2735 bfd *abfd;
2736 const char *msg;
2737 elf_property_list *p;
2738 bfd_boolean missing_ibt, missing_shstk;
2739 bfd_boolean check_ibt
2740 = !!(htab->params->cet_report & cet_report_ibt);
2741 bfd_boolean check_shstk
2742 = !!(htab->params->cet_report & cet_report_shstk);
2743
2744 if ((htab->params->cet_report & cet_report_warning))
2745 msg = _("%P: %pB: warning: missing %s\n");
2746 else
2747 msg = _("%X%P: %pB: error: missing %s\n");
2748
2749 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
2750 if (!(abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED))
2751 && bfd_get_flavour (abfd) == bfd_target_elf_flavour)
2752 {
2753 for (p = elf_properties (abfd); p; p = p->next)
2754 if (p->property.pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2755 break;
2756
2757 missing_ibt = check_ibt;
2758 missing_shstk = check_shstk;
2759 if (p)
2760 {
2761 missing_ibt &= !(p->property.u.number
2762 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2763 missing_shstk &= !(p->property.u.number
2764 & GNU_PROPERTY_X86_FEATURE_1_SHSTK);
2765 }
2766 if (missing_ibt || missing_shstk)
2767 {
2768 const char *missing;
2769 if (missing_ibt && missing_shstk)
2770 missing = _("IBT and SHSTK properties");
2771 else if (missing_ibt)
2772 missing = _("IBT property");
2773 else
2774 missing = _("SHSTK property");
2775 info->callbacks->einfo (msg, abfd, missing);
2776 }
2777 }
2778 }
2779
2780 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2781
2782 htab->r_info = init_table->r_info;
2783 htab->r_sym = init_table->r_sym;
2784
2785 if (bfd_link_relocatable (info))
2786 return pbfd;
2787
2788 htab->plt0_pad_byte = init_table->plt0_pad_byte;
2789
2790 use_ibt_plt = htab->params->ibtplt || htab->params->ibt;
2791 if (!use_ibt_plt && pbfd != NULL)
2792 {
2793 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2794 elf_property_list *p;
2795
2796 /* The property list is sorted in order of type. */
2797 for (p = elf_properties (pbfd); p; p = p->next)
2798 {
2799 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2800 {
2801 use_ibt_plt = !!(p->property.u.number
2802 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2803 break;
2804 }
2805 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2806 break;
2807 }
2808 }
2809
2810 dynobj = htab->elf.dynobj;
2811
2812 /* Set htab->elf.dynobj here so that there is no need to check and
2813 set it in check_relocs. */
2814 if (dynobj == NULL)
2815 {
2816 if (pbfd != NULL)
2817 {
2818 htab->elf.dynobj = pbfd;
2819 dynobj = pbfd;
2820 }
2821 else
2822 {
2823 bfd *abfd;
2824
2825 /* Find a normal input file to hold linker created
2826 sections. */
2827 for (abfd = info->input_bfds;
2828 abfd != NULL;
2829 abfd = abfd->link.next)
2830 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2831 && (abfd->flags
2832 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
2833 && bed->relocs_compatible (abfd->xvec,
2834 info->output_bfd->xvec))
2835 {
2836 htab->elf.dynobj = abfd;
2837 dynobj = abfd;
2838 break;
2839 }
2840 }
2841 }
2842
2843 /* Return if there are no normal input files. */
2844 if (dynobj == NULL)
2845 return pbfd;
2846
2847 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2848 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2849 canonical function address. */
2850 htab->plt.has_plt0 = 1;
2851 normal_target = htab->target_os == is_normal;
2852
2853 if (normal_target)
2854 {
2855 if (use_ibt_plt)
2856 {
2857 htab->lazy_plt = init_table->lazy_ibt_plt;
2858 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2859 }
2860 else
2861 {
2862 htab->lazy_plt = init_table->lazy_plt;
2863 htab->non_lazy_plt = init_table->non_lazy_plt;
2864 }
2865 }
2866 else
2867 {
2868 htab->lazy_plt = init_table->lazy_plt;
2869 htab->non_lazy_plt = NULL;
2870 }
2871
2872 pltsec = htab->elf.splt;
2873
2874 /* If the non-lazy PLT is available, use it for all PLT entries if
2875 there are no PLT0 or no .plt section. */
2876 if (htab->non_lazy_plt != NULL
2877 && (!htab->plt.has_plt0 || pltsec == NULL))
2878 {
2879 lazy_plt = FALSE;
2880 if (bfd_link_pic (info))
2881 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2882 else
2883 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2884 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2885 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2886 htab->plt.plt_got_insn_size
2887 = htab->non_lazy_plt->plt_got_insn_size;
2888 htab->plt.eh_frame_plt_size
2889 = htab->non_lazy_plt->eh_frame_plt_size;
2890 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2891 }
2892 else
2893 {
2894 lazy_plt = TRUE;
2895 if (bfd_link_pic (info))
2896 {
2897 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2898 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2899 }
2900 else
2901 {
2902 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2903 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2904 }
2905 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2906 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2907 htab->plt.plt_got_insn_size
2908 = htab->lazy_plt->plt_got_insn_size;
2909 htab->plt.eh_frame_plt_size
2910 = htab->lazy_plt->eh_frame_plt_size;
2911 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2912 }
2913
2914 if (htab->target_os == is_vxworks
2915 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2916 &htab->srelplt2))
2917 {
2918 info->callbacks->einfo (_("%F%P: failed to create VxWorks dynamic sections\n"));
2919 return pbfd;
2920 }
2921
2922 /* Since create_dynamic_sections isn't always called, but GOT
2923 relocations need GOT relocations, create them here so that we
2924 don't need to do it in check_relocs. */
2925 if (htab->elf.sgot == NULL
2926 && !_bfd_elf_create_got_section (dynobj, info))
2927 info->callbacks->einfo (_("%F%P: failed to create GOT sections\n"));
2928
2929 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2930
2931 /* Align .got and .got.plt sections to their entry size. Do it here
2932 instead of in create_dynamic_sections so that they are always
2933 properly aligned even if create_dynamic_sections isn't called. */
2934 sec = htab->elf.sgot;
2935 if (!bfd_set_section_alignment (sec, got_align))
2936 goto error_alignment;
2937
2938 sec = htab->elf.sgotplt;
2939 if (!bfd_set_section_alignment (sec, got_align))
2940 goto error_alignment;
2941
2942 /* Create the ifunc sections here so that check_relocs can be
2943 simplified. */
2944 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2945 info->callbacks->einfo (_("%F%P: failed to create ifunc sections\n"));
2946
2947 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2948
2949 if (pltsec != NULL)
2950 {
2951 /* Whe creating executable, set the contents of the .interp
2952 section to the interpreter. */
2953 if (bfd_link_executable (info) && !info->nointerp)
2954 {
2955 asection *s = bfd_get_linker_section (dynobj, ".interp");
2956 if (s == NULL)
2957 abort ();
2958 s->size = htab->dynamic_interpreter_size;
2959 s->contents = (unsigned char *) htab->dynamic_interpreter;
2960 htab->interp = s;
2961 }
2962
2963 /* Don't change PLT section alignment for NaCl since it uses
2964 64-byte PLT entry and sets PLT section alignment to 32
2965 bytes. Don't create additional PLT sections for NaCl. */
2966 if (normal_target)
2967 {
2968 flagword pltflags = (bed->dynamic_sec_flags
2969 | SEC_ALLOC
2970 | SEC_CODE
2971 | SEC_LOAD
2972 | SEC_READONLY);
2973 unsigned int non_lazy_plt_alignment
2974 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2975
2976 sec = pltsec;
2977 if (!bfd_set_section_alignment (sec, plt_alignment))
2978 goto error_alignment;
2979
2980 /* Create the GOT procedure linkage table. */
2981 sec = bfd_make_section_anyway_with_flags (dynobj,
2982 ".plt.got",
2983 pltflags);
2984 if (sec == NULL)
2985 info->callbacks->einfo (_("%F%P: failed to create GOT PLT section\n"));
2986
2987 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
2988 goto error_alignment;
2989
2990 htab->plt_got = sec;
2991
2992 if (lazy_plt)
2993 {
2994 sec = NULL;
2995
2996 if (use_ibt_plt)
2997 {
2998 /* Create the second PLT for Intel IBT support. IBT
2999 PLT is supported only for non-NaCl target and is
3000 is needed only for lazy binding. */
3001 sec = bfd_make_section_anyway_with_flags (dynobj,
3002 ".plt.sec",
3003 pltflags);
3004 if (sec == NULL)
3005 info->callbacks->einfo (_("%F%P: failed to create IBT-enabled PLT section\n"));
3006
3007 if (!bfd_set_section_alignment (sec, plt_alignment))
3008 goto error_alignment;
3009 }
3010 else if (htab->params->bndplt && ABI_64_P (dynobj))
3011 {
3012 /* Create the second PLT for Intel MPX support. MPX
3013 PLT is supported only for non-NaCl target in 64-bit
3014 mode and is needed only for lazy binding. */
3015 sec = bfd_make_section_anyway_with_flags (dynobj,
3016 ".plt.sec",
3017 pltflags);
3018 if (sec == NULL)
3019 info->callbacks->einfo (_("%F%P: failed to create BND PLT section\n"));
3020
3021 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
3022 goto error_alignment;
3023 }
3024
3025 htab->plt_second = sec;
3026 }
3027 }
3028
3029 if (!info->no_ld_generated_unwind_info)
3030 {
3031 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
3032 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
3033 | SEC_LINKER_CREATED);
3034
3035 sec = bfd_make_section_anyway_with_flags (dynobj,
3036 ".eh_frame",
3037 flags);
3038 if (sec == NULL)
3039 info->callbacks->einfo (_("%F%P: failed to create PLT .eh_frame section\n"));
3040
3041 if (!bfd_set_section_alignment (sec, class_align))
3042 goto error_alignment;
3043
3044 htab->plt_eh_frame = sec;
3045
3046 if (htab->plt_got != NULL)
3047 {
3048 sec = bfd_make_section_anyway_with_flags (dynobj,
3049 ".eh_frame",
3050 flags);
3051 if (sec == NULL)
3052 info->callbacks->einfo (_("%F%P: failed to create GOT PLT .eh_frame section\n"));
3053
3054 if (!bfd_set_section_alignment (sec, class_align))
3055 goto error_alignment;
3056
3057 htab->plt_got_eh_frame = sec;
3058 }
3059
3060 if (htab->plt_second != NULL)
3061 {
3062 sec = bfd_make_section_anyway_with_flags (dynobj,
3063 ".eh_frame",
3064 flags);
3065 if (sec == NULL)
3066 info->callbacks->einfo (_("%F%P: failed to create the second PLT .eh_frame section\n"));
3067
3068 if (!bfd_set_section_alignment (sec, class_align))
3069 goto error_alignment;
3070
3071 htab->plt_second_eh_frame = sec;
3072 }
3073 }
3074 }
3075
3076 /* The .iplt section is used for IFUNC symbols in static
3077 executables. */
3078 sec = htab->elf.iplt;
3079 if (sec != NULL)
3080 {
3081 /* NB: Delay setting its alignment until we know it is non-empty.
3082 Otherwise an empty iplt section may change vma and lma of the
3083 following sections, which triggers moving dot of the following
3084 section backwards, resulting in a warning and section lma not
3085 being set properly. It later leads to a "File truncated"
3086 error. */
3087 if (!bfd_set_section_alignment (sec, 0))
3088 goto error_alignment;
3089
3090 htab->plt.iplt_alignment = (normal_target
3091 ? plt_alignment
3092 : bed->plt_alignment);
3093 }
3094
3095 if (bfd_link_executable (info)
3096 && !info->nointerp
3097 && !htab->params->has_dynamic_linker
3098 && htab->params->static_before_all_inputs)
3099 {
3100 /* Report error for dynamic input objects if -static is passed at
3101 command-line before all input files without --dynamic-linker
3102 unless --no-dynamic-linker is used. */
3103 bfd *abfd;
3104
3105 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
3106 if ((abfd->flags & DYNAMIC))
3107 info->callbacks->einfo
3108 (_("%X%P: attempted static link of dynamic object `%pB'\n"),
3109 abfd);
3110 }
3111
3112 return pbfd;
3113 }
3114
3115 /* Fix up x86 GNU properties. */
3116
3117 void
3118 _bfd_x86_elf_link_fixup_gnu_properties
3119 (struct bfd_link_info *info ATTRIBUTE_UNUSED,
3120 elf_property_list **listp)
3121 {
3122 elf_property_list *p;
3123
3124 for (p = *listp; p; p = p->next)
3125 {
3126 unsigned int type = p->property.pr_type;
3127 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
3128 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3129 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3130 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3131 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3132 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
3133 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
3134 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
3135 {
3136 if (p->property.u.number == 0
3137 && (type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3138 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3139 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3140 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3141 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)))
3142 {
3143 /* Remove empty property. */
3144 *listp = p->next;
3145 continue;
3146 }
3147
3148 listp = &p->next;
3149 }
3150 else if (type > GNU_PROPERTY_HIPROC)
3151 {
3152 /* The property list is sorted in order of type. */
3153 break;
3154 }
3155 }
3156 }
3157
3158 void
3159 _bfd_elf_linker_x86_set_options (struct bfd_link_info * info,
3160 struct elf_linker_x86_params *params)
3161 {
3162 const struct elf_backend_data *bed
3163 = get_elf_backend_data (info->output_bfd);
3164 struct elf_x86_link_hash_table *htab
3165 = elf_x86_hash_table (info, bed->target_id);
3166 if (htab != NULL)
3167 htab->params = params;
3168 }
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