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x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker
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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 plt_entry_size,
136 (htab->plt.has_plt0
137 * plt_entry_size),
138 htab->got_entry_size,
139 TRUE))
140 {
141 asection *s = htab->plt_second;
142 if (h->plt.offset != (bfd_vma) -1 && s != NULL)
143 {
144 /* Use the second PLT section if it is created. */
145 eh->plt_second.offset = s->size;
146
147 /* Make room for this entry in the second PLT section. */
148 s->size += htab->non_lazy_plt->plt_entry_size;
149 }
150
151 return TRUE;
152 }
153 else
154 return FALSE;
155 }
156 /* Don't create the PLT entry if there are only function pointer
157 relocations which can be resolved at run-time. */
158 else if (htab->elf.dynamic_sections_created
159 && (h->plt.refcount > 0
160 || eh->plt_got.refcount > 0))
161 {
162 bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
163
164 /* Make sure this symbol is output as a dynamic symbol.
165 Undefined weak syms won't yet be marked as dynamic. */
166 if (h->dynindx == -1
167 && !h->forced_local
168 && !resolved_to_zero
169 && h->root.type == bfd_link_hash_undefweak)
170 {
171 if (! bfd_elf_link_record_dynamic_symbol (info, h))
172 return FALSE;
173 }
174
175 if (bfd_link_pic (info)
176 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
177 {
178 asection *s = htab->elf.splt;
179 asection *second_s = htab->plt_second;
180 asection *got_s = htab->plt_got;
181 bfd_boolean use_plt;
182
183 /* If this is the first .plt entry, make room for the special
184 first entry. The .plt section is used by prelink to undo
185 prelinking for dynamic relocations. */
186 if (s->size == 0)
187 s->size = htab->plt.has_plt0 * plt_entry_size;
188
189 if (use_plt_got)
190 eh->plt_got.offset = got_s->size;
191 else
192 {
193 h->plt.offset = s->size;
194 if (second_s)
195 eh->plt_second.offset = second_s->size;
196 }
197
198 /* If this symbol is not defined in a regular file, and we are
199 generating PDE, then set the symbol to this location in the
200 .plt. This is required to make function pointers compare
201 as equal between PDE and the shared library.
202
203 NB: If PLT is PC-relative, we can use the .plt in PIE for
204 function address. */
205 if (h->def_regular)
206 use_plt = FALSE;
207 else if (htab->pcrel_plt)
208 use_plt = ! bfd_link_dll (info);
209 else
210 use_plt = bfd_link_pde (info);
211 if (use_plt)
212 {
213 if (use_plt_got)
214 {
215 /* We need to make a call to the entry of the GOT PLT
216 instead of regular PLT entry. */
217 h->root.u.def.section = got_s;
218 h->root.u.def.value = eh->plt_got.offset;
219 }
220 else
221 {
222 if (second_s)
223 {
224 /* We need to make a call to the entry of the
225 second PLT instead of regular PLT entry. */
226 h->root.u.def.section = second_s;
227 h->root.u.def.value = eh->plt_second.offset;
228 }
229 else
230 {
231 h->root.u.def.section = s;
232 h->root.u.def.value = h->plt.offset;
233 }
234 }
235 }
236
237 /* Make room for this entry. */
238 if (use_plt_got)
239 got_s->size += htab->non_lazy_plt->plt_entry_size;
240 else
241 {
242 s->size += plt_entry_size;
243 if (second_s)
244 second_s->size += htab->non_lazy_plt->plt_entry_size;
245
246 /* We also need to make an entry in the .got.plt section,
247 which will be placed in the .got section by the linker
248 script. */
249 htab->elf.sgotplt->size += htab->got_entry_size;
250
251 /* There should be no PLT relocation against resolved
252 undefined weak symbol in executable. */
253 if (!resolved_to_zero)
254 {
255 /* We also need to make an entry in the .rel.plt
256 section. */
257 htab->elf.srelplt->size += htab->sizeof_reloc;
258 htab->elf.srelplt->reloc_count++;
259 }
260 }
261
262 if (htab->elf.target_os == is_vxworks && !bfd_link_pic (info))
263 {
264 /* VxWorks has a second set of relocations for each PLT entry
265 in executables. They go in a separate relocation section,
266 which is processed by the kernel loader. */
267
268 /* There are two relocations for the initial PLT entry: an
269 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
270 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
271
272 asection *srelplt2 = htab->srelplt2;
273 if (h->plt.offset == plt_entry_size)
274 srelplt2->size += (htab->sizeof_reloc * 2);
275
276 /* There are two extra relocations for each subsequent PLT entry:
277 an R_386_32 relocation for the GOT entry, and an R_386_32
278 relocation for the PLT entry. */
279
280 srelplt2->size += (htab->sizeof_reloc * 2);
281 }
282 }
283 else
284 {
285 eh->plt_got.offset = (bfd_vma) -1;
286 h->plt.offset = (bfd_vma) -1;
287 h->needs_plt = 0;
288 }
289 }
290 else
291 {
292 eh->plt_got.offset = (bfd_vma) -1;
293 h->plt.offset = (bfd_vma) -1;
294 h->needs_plt = 0;
295 }
296
297 eh->tlsdesc_got = (bfd_vma) -1;
298
299 /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the
300 binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For
301 x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary,
302 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
303 if (h->got.refcount > 0
304 && bfd_link_executable (info)
305 && h->dynindx == -1
306 && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
307 h->got.offset = (bfd_vma) -1;
308 else if (h->got.refcount > 0)
309 {
310 asection *s;
311 bfd_boolean dyn;
312 int tls_type = elf_x86_hash_entry (h)->tls_type;
313
314 /* Make sure this symbol is output as a dynamic symbol.
315 Undefined weak syms won't yet be marked as dynamic. */
316 if (h->dynindx == -1
317 && !h->forced_local
318 && !resolved_to_zero
319 && h->root.type == bfd_link_hash_undefweak)
320 {
321 if (! bfd_elf_link_record_dynamic_symbol (info, h))
322 return FALSE;
323 }
324
325 s = htab->elf.sgot;
326 if (GOT_TLS_GDESC_P (tls_type))
327 {
328 eh->tlsdesc_got = htab->elf.sgotplt->size
329 - elf_x86_compute_jump_table_size (htab);
330 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
331 h->got.offset = (bfd_vma) -2;
332 }
333 if (! GOT_TLS_GDESC_P (tls_type)
334 || GOT_TLS_GD_P (tls_type))
335 {
336 h->got.offset = s->size;
337 s->size += htab->got_entry_size;
338 /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT
339 slots. */
340 if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
341 s->size += htab->got_entry_size;
342 }
343 dyn = htab->elf.dynamic_sections_created;
344 /* R_386_TLS_IE_32 needs one dynamic relocation,
345 R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
346 (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
347 need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local
348 symbol and two if global. No dynamic relocation against
349 resolved undefined weak symbol in executable. No dynamic
350 relocation against non-preemptible absolute symbol. */
351 if (tls_type == GOT_TLS_IE_BOTH)
352 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
353 else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
354 || (tls_type & GOT_TLS_IE))
355 htab->elf.srelgot->size += htab->sizeof_reloc;
356 else if (GOT_TLS_GD_P (tls_type))
357 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
358 else if (! GOT_TLS_GDESC_P (tls_type)
359 && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
360 && !resolved_to_zero)
361 || h->root.type != bfd_link_hash_undefweak)
362 && ((bfd_link_pic (info)
363 && !(h->dynindx == -1
364 && ABS_SYMBOL_P (h)))
365 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
366 htab->elf.srelgot->size += htab->sizeof_reloc;
367 if (GOT_TLS_GDESC_P (tls_type))
368 {
369 htab->elf.srelplt->size += htab->sizeof_reloc;
370 if (bed->target_id == X86_64_ELF_DATA)
371 htab->elf.tlsdesc_plt = (bfd_vma) -1;
372 }
373 }
374 else
375 h->got.offset = (bfd_vma) -1;
376
377 if (h->dyn_relocs == NULL)
378 return TRUE;
379
380 /* In the shared -Bsymbolic case, discard space allocated for
381 dynamic pc-relative relocs against symbols which turn out to be
382 defined in regular objects. For the normal shared case, discard
383 space for pc-relative relocs that have become local due to symbol
384 visibility changes. */
385
386 if (bfd_link_pic (info))
387 {
388 /* Relocs that use pc_count are those that appear on a call
389 insn, or certain REL relocs that can generated via assembly.
390 We want calls to protected symbols to resolve directly to the
391 function rather than going via the plt. If people want
392 function pointer comparisons to work as expected then they
393 should avoid writing weird assembly. */
394 if (SYMBOL_CALLS_LOCAL (info, h))
395 {
396 struct elf_dyn_relocs **pp;
397
398 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
399 {
400 p->count -= p->pc_count;
401 p->pc_count = 0;
402 if (p->count == 0)
403 *pp = p->next;
404 else
405 pp = &p->next;
406 }
407 }
408
409 if (htab->elf.target_os == is_vxworks)
410 {
411 struct elf_dyn_relocs **pp;
412 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
413 {
414 if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
415 *pp = p->next;
416 else
417 pp = &p->next;
418 }
419 }
420
421 /* Also discard relocs on undefined weak syms with non-default
422 visibility or in PIE. */
423 if (h->dyn_relocs != NULL)
424 {
425 if (h->root.type == bfd_link_hash_undefweak)
426 {
427 /* Undefined weak symbol is never bound locally in shared
428 library. */
429 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
430 || resolved_to_zero)
431 {
432 if (bed->target_id == I386_ELF_DATA
433 && h->non_got_ref)
434 {
435 /* Keep dynamic non-GOT/non-PLT relocation so
436 that we can branch to 0 without PLT. */
437 struct elf_dyn_relocs **pp;
438
439 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
440 if (p->pc_count == 0)
441 *pp = p->next;
442 else
443 {
444 /* Remove non-R_386_PC32 relocation. */
445 p->count = p->pc_count;
446 pp = &p->next;
447 }
448
449 /* Make sure undefined weak symbols are output
450 as dynamic symbols in PIEs for dynamic non-GOT
451 non-PLT reloations. */
452 if (h->dyn_relocs != NULL
453 && !bfd_elf_link_record_dynamic_symbol (info, h))
454 return FALSE;
455 }
456 else
457 h->dyn_relocs = NULL;
458 }
459 else if (h->dynindx == -1
460 && !h->forced_local
461 && !bfd_elf_link_record_dynamic_symbol (info, h))
462 return FALSE;
463 }
464 else if (bfd_link_executable (info)
465 && (h->needs_copy || eh->needs_copy)
466 && h->def_dynamic
467 && !h->def_regular)
468 {
469 /* NB: needs_copy is set only for x86-64. For PIE,
470 discard space for pc-relative relocs against symbols
471 which turn out to need copy relocs. */
472 struct elf_dyn_relocs **pp;
473
474 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
475 {
476 if (p->pc_count != 0)
477 *pp = p->next;
478 else
479 pp = &p->next;
480 }
481 }
482 }
483 }
484 else if (ELIMINATE_COPY_RELOCS)
485 {
486 /* For the non-shared case, discard space for relocs against
487 symbols which turn out to need copy relocs or are not
488 dynamic. Keep dynamic relocations for run-time function
489 pointer initialization. */
490
491 if ((!h->non_got_ref
492 || (h->root.type == bfd_link_hash_undefweak
493 && !resolved_to_zero))
494 && ((h->def_dynamic
495 && !h->def_regular)
496 || (htab->elf.dynamic_sections_created
497 && (h->root.type == bfd_link_hash_undefweak
498 || h->root.type == bfd_link_hash_undefined))))
499 {
500 /* Make sure this symbol is output as a dynamic symbol.
501 Undefined weak syms won't yet be marked as dynamic. */
502 if (h->dynindx == -1
503 && !h->forced_local
504 && !resolved_to_zero
505 && h->root.type == bfd_link_hash_undefweak
506 && ! bfd_elf_link_record_dynamic_symbol (info, h))
507 return FALSE;
508
509 /* If that succeeded, we know we'll be keeping all the
510 relocs. */
511 if (h->dynindx != -1)
512 goto keep;
513 }
514
515 h->dyn_relocs = NULL;
516
517 keep: ;
518 }
519
520 /* Finally, allocate space. */
521 for (p = h->dyn_relocs; p != NULL; p = p->next)
522 {
523 asection *sreloc;
524
525 sreloc = elf_section_data (p->sec)->sreloc;
526
527 BFD_ASSERT (sreloc != NULL);
528 sreloc->size += p->count * htab->sizeof_reloc;
529 }
530
531 return TRUE;
532 }
533
534 /* Allocate space in .plt, .got and associated reloc sections for
535 local dynamic relocs. */
536
537 static bfd_boolean
538 elf_x86_allocate_local_dynreloc (void **slot, void *inf)
539 {
540 struct elf_link_hash_entry *h
541 = (struct elf_link_hash_entry *) *slot;
542
543 if (h->type != STT_GNU_IFUNC
544 || !h->def_regular
545 || !h->ref_regular
546 || !h->forced_local
547 || h->root.type != bfd_link_hash_defined)
548 abort ();
549
550 return elf_x86_allocate_dynrelocs (h, inf);
551 }
552
553 /* Find and/or create a hash entry for local symbol. */
554
555 struct elf_link_hash_entry *
556 _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab,
557 bfd *abfd, const Elf_Internal_Rela *rel,
558 bfd_boolean create)
559 {
560 struct elf_x86_link_hash_entry e, *ret;
561 asection *sec = abfd->sections;
562 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id,
563 htab->r_sym (rel->r_info));
564 void **slot;
565
566 e.elf.indx = sec->id;
567 e.elf.dynstr_index = htab->r_sym (rel->r_info);
568 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h,
569 create ? INSERT : NO_INSERT);
570
571 if (!slot)
572 return NULL;
573
574 if (*slot)
575 {
576 ret = (struct elf_x86_link_hash_entry *) *slot;
577 return &ret->elf;
578 }
579
580 ret = (struct elf_x86_link_hash_entry *)
581 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory,
582 sizeof (struct elf_x86_link_hash_entry));
583 if (ret)
584 {
585 memset (ret, 0, sizeof (*ret));
586 ret->elf.indx = sec->id;
587 ret->elf.dynstr_index = htab->r_sym (rel->r_info);
588 ret->elf.dynindx = -1;
589 ret->plt_got.offset = (bfd_vma) -1;
590 *slot = ret;
591 }
592 return &ret->elf;
593 }
594
595 /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN
596 SYNC WITH _bfd_elf_link_hash_newfunc. */
597
598 struct bfd_hash_entry *
599 _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry,
600 struct bfd_hash_table *table,
601 const char *string)
602 {
603 /* Allocate the structure if it has not already been allocated by a
604 subclass. */
605 if (entry == NULL)
606 {
607 entry = (struct bfd_hash_entry *)
608 bfd_hash_allocate (table,
609 sizeof (struct elf_x86_link_hash_entry));
610 if (entry == NULL)
611 return entry;
612 }
613
614 /* Call the allocation method of the superclass. */
615 entry = _bfd_link_hash_newfunc (entry, table, string);
616 if (entry != NULL)
617 {
618 struct elf_x86_link_hash_entry *eh
619 = (struct elf_x86_link_hash_entry *) entry;
620 struct elf_link_hash_table *htab
621 = (struct elf_link_hash_table *) table;
622
623 memset (&eh->elf.size, 0,
624 (sizeof (struct elf_x86_link_hash_entry)
625 - offsetof (struct elf_link_hash_entry, size)));
626 /* Set local fields. */
627 eh->elf.indx = -1;
628 eh->elf.dynindx = -1;
629 eh->elf.got = htab->init_got_refcount;
630 eh->elf.plt = htab->init_plt_refcount;
631 /* Assume that we have been called by a non-ELF symbol reader.
632 This flag is then reset by the code which reads an ELF input
633 file. This ensures that a symbol created by a non-ELF symbol
634 reader will have the flag set correctly. */
635 eh->elf.non_elf = 1;
636 eh->plt_second.offset = (bfd_vma) -1;
637 eh->plt_got.offset = (bfd_vma) -1;
638 eh->tlsdesc_got = (bfd_vma) -1;
639 eh->zero_undefweak = 1;
640 }
641
642 return entry;
643 }
644
645 /* Compute a hash of a local hash entry. We use elf_link_hash_entry
646 for local symbol so that we can handle local STT_GNU_IFUNC symbols
647 as global symbol. We reuse indx and dynstr_index for local symbol
648 hash since they aren't used by global symbols in this backend. */
649
650 hashval_t
651 _bfd_x86_elf_local_htab_hash (const void *ptr)
652 {
653 struct elf_link_hash_entry *h
654 = (struct elf_link_hash_entry *) ptr;
655 return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index);
656 }
657
658 /* Compare local hash entries. */
659
660 int
661 _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2)
662 {
663 struct elf_link_hash_entry *h1
664 = (struct elf_link_hash_entry *) ptr1;
665 struct elf_link_hash_entry *h2
666 = (struct elf_link_hash_entry *) ptr2;
667
668 return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index;
669 }
670
671 /* Destroy an x86 ELF linker hash table. */
672
673 static void
674 elf_x86_link_hash_table_free (bfd *obfd)
675 {
676 struct elf_x86_link_hash_table *htab
677 = (struct elf_x86_link_hash_table *) obfd->link.hash;
678
679 if (htab->loc_hash_table)
680 htab_delete (htab->loc_hash_table);
681 if (htab->loc_hash_memory)
682 objalloc_free ((struct objalloc *) htab->loc_hash_memory);
683 _bfd_elf_link_hash_table_free (obfd);
684 }
685
686 static bfd_boolean
687 elf_i386_is_reloc_section (const char *secname)
688 {
689 return CONST_STRNEQ (secname, ".rel");
690 }
691
692 static bfd_boolean
693 elf_x86_64_is_reloc_section (const char *secname)
694 {
695 return CONST_STRNEQ (secname, ".rela");
696 }
697
698 /* Create an x86 ELF linker hash table. */
699
700 struct bfd_link_hash_table *
701 _bfd_x86_elf_link_hash_table_create (bfd *abfd)
702 {
703 struct elf_x86_link_hash_table *ret;
704 const struct elf_backend_data *bed;
705 size_t amt = sizeof (struct elf_x86_link_hash_table);
706
707 ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt);
708 if (ret == NULL)
709 return NULL;
710
711 bed = get_elf_backend_data (abfd);
712 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd,
713 _bfd_x86_elf_link_hash_newfunc,
714 sizeof (struct elf_x86_link_hash_entry),
715 bed->target_id))
716 {
717 free (ret);
718 return NULL;
719 }
720
721 if (bed->target_id == X86_64_ELF_DATA)
722 {
723 ret->is_reloc_section = elf_x86_64_is_reloc_section;
724 ret->got_entry_size = 8;
725 ret->pcrel_plt = TRUE;
726 ret->tls_get_addr = "__tls_get_addr";
727 }
728 if (ABI_64_P (abfd))
729 {
730 ret->sizeof_reloc = sizeof (Elf64_External_Rela);
731 ret->pointer_r_type = R_X86_64_64;
732 ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER;
733 ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER;
734 }
735 else
736 {
737 if (bed->target_id == X86_64_ELF_DATA)
738 {
739 ret->sizeof_reloc = sizeof (Elf32_External_Rela);
740 ret->pointer_r_type = R_X86_64_32;
741 ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER;
742 ret->dynamic_interpreter_size
743 = sizeof ELFX32_DYNAMIC_INTERPRETER;
744 }
745 else
746 {
747 ret->is_reloc_section = elf_i386_is_reloc_section;
748 ret->sizeof_reloc = sizeof (Elf32_External_Rel);
749 ret->got_entry_size = 4;
750 ret->pcrel_plt = FALSE;
751 ret->pointer_r_type = R_386_32;
752 ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER;
753 ret->dynamic_interpreter_size
754 = sizeof ELF32_DYNAMIC_INTERPRETER;
755 ret->tls_get_addr = "___tls_get_addr";
756 }
757 }
758
759 ret->loc_hash_table = htab_try_create (1024,
760 _bfd_x86_elf_local_htab_hash,
761 _bfd_x86_elf_local_htab_eq,
762 NULL);
763 ret->loc_hash_memory = objalloc_create ();
764 if (!ret->loc_hash_table || !ret->loc_hash_memory)
765 {
766 elf_x86_link_hash_table_free (abfd);
767 return NULL;
768 }
769 ret->elf.root.hash_table_free = elf_x86_link_hash_table_free;
770
771 return &ret->elf.root;
772 }
773
774 /* Sort relocs into address order. */
775
776 int
777 _bfd_x86_elf_compare_relocs (const void *ap, const void *bp)
778 {
779 const arelent *a = * (const arelent **) ap;
780 const arelent *b = * (const arelent **) bp;
781
782 if (a->address > b->address)
783 return 1;
784 else if (a->address < b->address)
785 return -1;
786 else
787 return 0;
788 }
789
790 /* Mark symbol, NAME, as locally defined by linker if it is referenced
791 and not defined in a relocatable object file. */
792
793 static void
794 elf_x86_linker_defined (struct bfd_link_info *info, const char *name)
795 {
796 struct elf_link_hash_entry *h;
797
798 h = elf_link_hash_lookup (elf_hash_table (info), name,
799 FALSE, FALSE, FALSE);
800 if (h == NULL)
801 return;
802
803 while (h->root.type == bfd_link_hash_indirect)
804 h = (struct elf_link_hash_entry *) h->root.u.i.link;
805
806 if (h->root.type == bfd_link_hash_new
807 || h->root.type == bfd_link_hash_undefined
808 || h->root.type == bfd_link_hash_undefweak
809 || h->root.type == bfd_link_hash_common
810 || (!h->def_regular && h->def_dynamic))
811 {
812 elf_x86_hash_entry (h)->local_ref = 2;
813 elf_x86_hash_entry (h)->linker_def = 1;
814 }
815 }
816
817 /* Hide a linker-defined symbol, NAME, with hidden visibility. */
818
819 static void
820 elf_x86_hide_linker_defined (struct bfd_link_info *info,
821 const char *name)
822 {
823 struct elf_link_hash_entry *h;
824
825 h = elf_link_hash_lookup (elf_hash_table (info), name,
826 FALSE, FALSE, FALSE);
827 if (h == NULL)
828 return;
829
830 while (h->root.type == bfd_link_hash_indirect)
831 h = (struct elf_link_hash_entry *) h->root.u.i.link;
832
833 if (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
834 || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN)
835 _bfd_elf_link_hash_hide_symbol (info, h, TRUE);
836 }
837
838 bfd_boolean
839 _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
840 {
841 if (!bfd_link_relocatable (info))
842 {
843 /* Check for __tls_get_addr reference. */
844 struct elf_x86_link_hash_table *htab;
845 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
846 htab = elf_x86_hash_table (info, bed->target_id);
847 if (htab)
848 {
849 struct elf_link_hash_entry *h;
850
851 h = elf_link_hash_lookup (elf_hash_table (info),
852 htab->tls_get_addr,
853 FALSE, FALSE, FALSE);
854 if (h != NULL)
855 {
856 elf_x86_hash_entry (h)->tls_get_addr = 1;
857
858 /* Check the versioned __tls_get_addr symbol. */
859 while (h->root.type == bfd_link_hash_indirect)
860 {
861 h = (struct elf_link_hash_entry *) h->root.u.i.link;
862 elf_x86_hash_entry (h)->tls_get_addr = 1;
863 }
864 }
865
866 /* "__ehdr_start" will be defined by linker as a hidden symbol
867 later if it is referenced and not defined. */
868 elf_x86_linker_defined (info, "__ehdr_start");
869
870 if (bfd_link_executable (info))
871 {
872 /* References to __bss_start, _end and _edata should be
873 locally resolved within executables. */
874 elf_x86_linker_defined (info, "__bss_start");
875 elf_x86_linker_defined (info, "_end");
876 elf_x86_linker_defined (info, "_edata");
877 }
878 else
879 {
880 /* Hide hidden __bss_start, _end and _edata in shared
881 libraries. */
882 elf_x86_hide_linker_defined (info, "__bss_start");
883 elf_x86_hide_linker_defined (info, "_end");
884 elf_x86_hide_linker_defined (info, "_edata");
885 }
886 }
887 }
888
889 /* Invoke the regular ELF backend linker to do all the work. */
890 return _bfd_elf_link_check_relocs (abfd, info);
891 }
892
893 bfd_boolean
894 _bfd_elf_x86_valid_reloc_p (asection *input_section,
895 struct bfd_link_info *info,
896 struct elf_x86_link_hash_table *htab,
897 const Elf_Internal_Rela *rel,
898 struct elf_link_hash_entry *h,
899 Elf_Internal_Sym *sym,
900 Elf_Internal_Shdr *symtab_hdr,
901 bfd_boolean *no_dynreloc_p)
902 {
903 bfd_boolean valid_p = TRUE;
904
905 *no_dynreloc_p = FALSE;
906
907 /* Check If relocation against non-preemptible absolute symbol is
908 valid in PIC. FIXME: Can't use SYMBOL_REFERENCES_LOCAL_P since
909 it may call _bfd_elf_link_hide_sym_by_version and result in
910 ld-elfvers/ vers21 test failure. */
911 if (bfd_link_pic (info)
912 && (h == NULL || SYMBOL_REFERENCES_LOCAL (info, h)))
913 {
914 const struct elf_backend_data *bed;
915 unsigned int r_type;
916 Elf_Internal_Rela irel;
917
918 /* Skip non-absolute symbol. */
919 if (h)
920 {
921 if (!ABS_SYMBOL_P (h))
922 return valid_p;
923 }
924 else if (sym->st_shndx != SHN_ABS)
925 return valid_p;
926
927 bed = get_elf_backend_data (input_section->owner);
928 r_type = ELF32_R_TYPE (rel->r_info);
929 irel = *rel;
930
931 /* Only allow relocations against absolute symbol, which can be
932 resolved as absolute value + addend. GOTPCREL relocations
933 are allowed since absolute value + addend is stored in the
934 GOT slot. */
935 if (bed->target_id == X86_64_ELF_DATA)
936 {
937 r_type &= ~R_X86_64_converted_reloc_bit;
938 valid_p = (r_type == R_X86_64_64
939 || r_type == R_X86_64_32
940 || r_type == R_X86_64_32S
941 || r_type == R_X86_64_16
942 || r_type == R_X86_64_8
943 || r_type == R_X86_64_GOTPCREL
944 || r_type == R_X86_64_GOTPCRELX
945 || r_type == R_X86_64_REX_GOTPCRELX);
946 if (!valid_p)
947 {
948 unsigned int r_symndx = htab->r_sym (rel->r_info);
949 irel.r_info = htab->r_info (r_symndx, r_type);
950 }
951 }
952 else
953 valid_p = (r_type == R_386_32
954 || r_type == R_386_16
955 || r_type == R_386_8);
956
957 if (valid_p)
958 *no_dynreloc_p = TRUE;
959 else
960 {
961 const char *name;
962 arelent internal_reloc;
963
964 if (!bed->elf_info_to_howto (input_section->owner,
965 &internal_reloc, &irel)
966 || internal_reloc.howto == NULL)
967 abort ();
968
969 if (h)
970 name = h->root.root.string;
971 else
972 name = bfd_elf_sym_name (input_section->owner, symtab_hdr,
973 sym, NULL);
974 info->callbacks->einfo
975 /* xgettext:c-format */
976 (_("%F%P: %pB: relocation %s against absolute symbol "
977 "`%s' in section `%pA' is disallowed\n"),
978 input_section->owner, internal_reloc.howto->name, name,
979 input_section);
980 bfd_set_error (bfd_error_bad_value);
981 }
982 }
983
984 return valid_p;
985 }
986
987 /* Set the sizes of the dynamic sections. */
988
989 bfd_boolean
990 _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
991 struct bfd_link_info *info)
992 {
993 struct elf_x86_link_hash_table *htab;
994 bfd *dynobj;
995 asection *s;
996 bfd_boolean relocs;
997 bfd *ibfd;
998 const struct elf_backend_data *bed
999 = get_elf_backend_data (output_bfd);
1000
1001 htab = elf_x86_hash_table (info, bed->target_id);
1002 if (htab == NULL)
1003 return FALSE;
1004 dynobj = htab->elf.dynobj;
1005 if (dynobj == NULL)
1006 abort ();
1007
1008 /* Set up .got offsets for local syms, and space for local dynamic
1009 relocs. */
1010 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
1011 {
1012 bfd_signed_vma *local_got;
1013 bfd_signed_vma *end_local_got;
1014 char *local_tls_type;
1015 bfd_vma *local_tlsdesc_gotent;
1016 bfd_size_type locsymcount;
1017 Elf_Internal_Shdr *symtab_hdr;
1018 asection *srel;
1019
1020 if (! is_x86_elf (ibfd, htab))
1021 continue;
1022
1023 for (s = ibfd->sections; s != NULL; s = s->next)
1024 {
1025 struct elf_dyn_relocs *p;
1026
1027 for (p = ((struct elf_dyn_relocs *)
1028 elf_section_data (s)->local_dynrel);
1029 p != NULL;
1030 p = p->next)
1031 {
1032 if (!bfd_is_abs_section (p->sec)
1033 && bfd_is_abs_section (p->sec->output_section))
1034 {
1035 /* Input section has been discarded, either because
1036 it is a copy of a linkonce section or due to
1037 linker script /DISCARD/, so we'll be discarding
1038 the relocs too. */
1039 }
1040 else if (htab->elf.target_os == is_vxworks
1041 && strcmp (p->sec->output_section->name,
1042 ".tls_vars") == 0)
1043 {
1044 /* Relocations in vxworks .tls_vars sections are
1045 handled specially by the loader. */
1046 }
1047 else if (p->count != 0)
1048 {
1049 srel = elf_section_data (p->sec)->sreloc;
1050 srel->size += p->count * htab->sizeof_reloc;
1051 if ((p->sec->output_section->flags & SEC_READONLY) != 0
1052 && (info->flags & DF_TEXTREL) == 0)
1053 {
1054 info->flags |= DF_TEXTREL;
1055 if (bfd_link_textrel_check (info))
1056 /* xgettext:c-format */
1057 info->callbacks->einfo
1058 (_("%P: %pB: warning: relocation "
1059 "in read-only section `%pA'\n"),
1060 p->sec->owner, p->sec);
1061 }
1062 }
1063 }
1064 }
1065
1066 local_got = elf_local_got_refcounts (ibfd);
1067 if (!local_got)
1068 continue;
1069
1070 symtab_hdr = &elf_symtab_hdr (ibfd);
1071 locsymcount = symtab_hdr->sh_info;
1072 end_local_got = local_got + locsymcount;
1073 local_tls_type = elf_x86_local_got_tls_type (ibfd);
1074 local_tlsdesc_gotent = elf_x86_local_tlsdesc_gotent (ibfd);
1075 s = htab->elf.sgot;
1076 srel = htab->elf.srelgot;
1077 for (; local_got < end_local_got;
1078 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
1079 {
1080 *local_tlsdesc_gotent = (bfd_vma) -1;
1081 if (*local_got > 0)
1082 {
1083 if (GOT_TLS_GDESC_P (*local_tls_type))
1084 {
1085 *local_tlsdesc_gotent = htab->elf.sgotplt->size
1086 - elf_x86_compute_jump_table_size (htab);
1087 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
1088 *local_got = (bfd_vma) -2;
1089 }
1090 if (! GOT_TLS_GDESC_P (*local_tls_type)
1091 || GOT_TLS_GD_P (*local_tls_type))
1092 {
1093 *local_got = s->size;
1094 s->size += htab->got_entry_size;
1095 if (GOT_TLS_GD_P (*local_tls_type)
1096 || *local_tls_type == GOT_TLS_IE_BOTH)
1097 s->size += htab->got_entry_size;
1098 }
1099 if ((bfd_link_pic (info) && *local_tls_type != GOT_ABS)
1100 || GOT_TLS_GD_ANY_P (*local_tls_type)
1101 || (*local_tls_type & GOT_TLS_IE))
1102 {
1103 if (*local_tls_type == GOT_TLS_IE_BOTH)
1104 srel->size += 2 * htab->sizeof_reloc;
1105 else if (GOT_TLS_GD_P (*local_tls_type)
1106 || ! GOT_TLS_GDESC_P (*local_tls_type))
1107 srel->size += htab->sizeof_reloc;
1108 if (GOT_TLS_GDESC_P (*local_tls_type))
1109 {
1110 htab->elf.srelplt->size += htab->sizeof_reloc;
1111 if (bed->target_id == X86_64_ELF_DATA)
1112 htab->elf.tlsdesc_plt = (bfd_vma) -1;
1113 }
1114 }
1115 }
1116 else
1117 *local_got = (bfd_vma) -1;
1118 }
1119 }
1120
1121 if (htab->tls_ld_or_ldm_got.refcount > 0)
1122 {
1123 /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM
1124 or R_X86_64_TLSLD relocs. */
1125 htab->tls_ld_or_ldm_got.offset = htab->elf.sgot->size;
1126 htab->elf.sgot->size += 2 * htab->got_entry_size;
1127 htab->elf.srelgot->size += htab->sizeof_reloc;
1128 }
1129 else
1130 htab->tls_ld_or_ldm_got.offset = -1;
1131
1132 /* Allocate global sym .plt and .got entries, and space for global
1133 sym dynamic relocs. */
1134 elf_link_hash_traverse (&htab->elf, elf_x86_allocate_dynrelocs,
1135 info);
1136
1137 /* Allocate .plt and .got entries, and space for local symbols. */
1138 htab_traverse (htab->loc_hash_table, elf_x86_allocate_local_dynreloc,
1139 info);
1140
1141 /* For every jump slot reserved in the sgotplt, reloc_count is
1142 incremented. However, when we reserve space for TLS descriptors,
1143 it's not incremented, so in order to compute the space reserved
1144 for them, it suffices to multiply the reloc count by the jump
1145 slot size.
1146
1147 PR ld/13302: We start next_irelative_index at the end of .rela.plt
1148 so that R_{386,X86_64}_IRELATIVE entries come last. */
1149 if (htab->elf.srelplt)
1150 {
1151 htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
1152 htab->sgotplt_jump_table_size
1153 = elf_x86_compute_jump_table_size (htab);
1154 htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
1155 }
1156 else if (htab->elf.irelplt)
1157 htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
1158
1159 if (htab->elf.tlsdesc_plt)
1160 {
1161 /* NB: tlsdesc_plt is set only for x86-64. If we're not using
1162 lazy TLS relocations, don't generate the PLT and GOT entries
1163 they require. */
1164 if ((info->flags & DF_BIND_NOW))
1165 htab->elf.tlsdesc_plt = 0;
1166 else
1167 {
1168 htab->elf.tlsdesc_got = htab->elf.sgot->size;
1169 htab->elf.sgot->size += htab->got_entry_size;
1170 /* Reserve room for the initial entry.
1171 FIXME: we could probably do away with it in this case. */
1172 if (htab->elf.splt->size == 0)
1173 htab->elf.splt->size = htab->plt.plt_entry_size;
1174 htab->elf.tlsdesc_plt = htab->elf.splt->size;
1175 htab->elf.splt->size += htab->plt.plt_entry_size;
1176 }
1177 }
1178
1179 if (htab->elf.sgotplt)
1180 {
1181 /* Don't allocate .got.plt section if there are no GOT nor PLT
1182 entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */
1183 if ((htab->elf.hgot == NULL
1184 || !htab->got_referenced)
1185 && (htab->elf.sgotplt->size == bed->got_header_size)
1186 && (htab->elf.splt == NULL
1187 || htab->elf.splt->size == 0)
1188 && (htab->elf.sgot == NULL
1189 || htab->elf.sgot->size == 0)
1190 && (htab->elf.iplt == NULL
1191 || htab->elf.iplt->size == 0)
1192 && (htab->elf.igotplt == NULL
1193 || htab->elf.igotplt->size == 0))
1194 {
1195 htab->elf.sgotplt->size = 0;
1196 /* Solaris requires to keep _GLOBAL_OFFSET_TABLE_ even if it
1197 isn't used. */
1198 if (htab->elf.hgot != NULL
1199 && htab->elf.target_os != is_solaris)
1200 {
1201 /* Remove the unused _GLOBAL_OFFSET_TABLE_ from symbol
1202 table. */
1203 htab->elf.hgot->root.type = bfd_link_hash_undefined;
1204 htab->elf.hgot->root.u.undef.abfd
1205 = htab->elf.hgot->root.u.def.section->owner;
1206 htab->elf.hgot->root.linker_def = 0;
1207 htab->elf.hgot->ref_regular = 0;
1208 htab->elf.hgot->def_regular = 0;
1209 }
1210 }
1211 }
1212
1213 if (_bfd_elf_eh_frame_present (info))
1214 {
1215 if (htab->plt_eh_frame != NULL
1216 && htab->elf.splt != NULL
1217 && htab->elf.splt->size != 0
1218 && !bfd_is_abs_section (htab->elf.splt->output_section))
1219 htab->plt_eh_frame->size = htab->plt.eh_frame_plt_size;
1220
1221 if (htab->plt_got_eh_frame != NULL
1222 && htab->plt_got != NULL
1223 && htab->plt_got->size != 0
1224 && !bfd_is_abs_section (htab->plt_got->output_section))
1225 htab->plt_got_eh_frame->size
1226 = htab->non_lazy_plt->eh_frame_plt_size;
1227
1228 /* Unwind info for the second PLT and .plt.got sections are
1229 identical. */
1230 if (htab->plt_second_eh_frame != NULL
1231 && htab->plt_second != NULL
1232 && htab->plt_second->size != 0
1233 && !bfd_is_abs_section (htab->plt_second->output_section))
1234 htab->plt_second_eh_frame->size
1235 = htab->non_lazy_plt->eh_frame_plt_size;
1236 }
1237
1238 /* We now have determined the sizes of the various dynamic sections.
1239 Allocate memory for them. */
1240 relocs = FALSE;
1241 for (s = dynobj->sections; s != NULL; s = s->next)
1242 {
1243 bfd_boolean strip_section = TRUE;
1244
1245 if ((s->flags & SEC_LINKER_CREATED) == 0)
1246 continue;
1247
1248 if (s == htab->elf.splt
1249 || s == htab->elf.sgot)
1250 {
1251 /* Strip this section if we don't need it; see the
1252 comment below. */
1253 /* We'd like to strip these sections if they aren't needed, but if
1254 we've exported dynamic symbols from them we must leave them.
1255 It's too late to tell BFD to get rid of the symbols. */
1256
1257 if (htab->elf.hplt != NULL)
1258 strip_section = FALSE;
1259 }
1260 else if (s == htab->elf.sgotplt
1261 || s == htab->elf.iplt
1262 || s == htab->elf.igotplt
1263 || s == htab->plt_second
1264 || s == htab->plt_got
1265 || s == htab->plt_eh_frame
1266 || s == htab->plt_got_eh_frame
1267 || s == htab->plt_second_eh_frame
1268 || s == htab->elf.sdynbss
1269 || s == htab->elf.sdynrelro)
1270 {
1271 /* Strip these too. */
1272 }
1273 else if (htab->is_reloc_section (bfd_section_name (s)))
1274 {
1275 if (s->size != 0
1276 && s != htab->elf.srelplt
1277 && s != htab->srelplt2)
1278 relocs = TRUE;
1279
1280 /* We use the reloc_count field as a counter if we need
1281 to copy relocs into the output file. */
1282 if (s != htab->elf.srelplt)
1283 s->reloc_count = 0;
1284 }
1285 else
1286 {
1287 /* It's not one of our sections, so don't allocate space. */
1288 continue;
1289 }
1290
1291 if (s->size == 0)
1292 {
1293 /* If we don't need this section, strip it from the
1294 output file. This is mostly to handle .rel.bss and
1295 .rel.plt. We must create both sections in
1296 create_dynamic_sections, because they must be created
1297 before the linker maps input sections to output
1298 sections. The linker does that before
1299 adjust_dynamic_symbol is called, and it is that
1300 function which decides whether anything needs to go
1301 into these sections. */
1302 if (strip_section)
1303 s->flags |= SEC_EXCLUDE;
1304 continue;
1305 }
1306
1307 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1308 continue;
1309
1310 /* NB: Initially, the iplt section has minimal alignment to
1311 avoid moving dot of the following section backwards when
1312 it is empty. Update its section alignment now since it
1313 is non-empty. */
1314 if (s == htab->elf.iplt)
1315 bfd_set_section_alignment (s, htab->plt.iplt_alignment);
1316
1317 /* Allocate memory for the section contents. We use bfd_zalloc
1318 here in case unused entries are not reclaimed before the
1319 section's contents are written out. This should not happen,
1320 but this way if it does, we get a R_386_NONE or R_X86_64_NONE
1321 reloc instead of garbage. */
1322 s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size);
1323 if (s->contents == NULL)
1324 return FALSE;
1325 }
1326
1327 if (htab->plt_eh_frame != NULL
1328 && htab->plt_eh_frame->contents != NULL)
1329 {
1330 memcpy (htab->plt_eh_frame->contents,
1331 htab->plt.eh_frame_plt,
1332 htab->plt_eh_frame->size);
1333 bfd_put_32 (dynobj, htab->elf.splt->size,
1334 htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET);
1335 }
1336
1337 if (htab->plt_got_eh_frame != NULL
1338 && htab->plt_got_eh_frame->contents != NULL)
1339 {
1340 memcpy (htab->plt_got_eh_frame->contents,
1341 htab->non_lazy_plt->eh_frame_plt,
1342 htab->plt_got_eh_frame->size);
1343 bfd_put_32 (dynobj, htab->plt_got->size,
1344 (htab->plt_got_eh_frame->contents
1345 + PLT_FDE_LEN_OFFSET));
1346 }
1347
1348 if (htab->plt_second_eh_frame != NULL
1349 && htab->plt_second_eh_frame->contents != NULL)
1350 {
1351 memcpy (htab->plt_second_eh_frame->contents,
1352 htab->non_lazy_plt->eh_frame_plt,
1353 htab->plt_second_eh_frame->size);
1354 bfd_put_32 (dynobj, htab->plt_second->size,
1355 (htab->plt_second_eh_frame->contents
1356 + PLT_FDE_LEN_OFFSET));
1357 }
1358
1359 return _bfd_elf_maybe_vxworks_add_dynamic_tags (output_bfd, info,
1360 relocs);
1361 }
1362
1363 /* Finish up the x86 dynamic sections. */
1364
1365 struct elf_x86_link_hash_table *
1366 _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd,
1367 struct bfd_link_info *info)
1368 {
1369 struct elf_x86_link_hash_table *htab;
1370 const struct elf_backend_data *bed;
1371 bfd *dynobj;
1372 asection *sdyn;
1373 bfd_byte *dyncon, *dynconend;
1374 bfd_size_type sizeof_dyn;
1375
1376 bed = get_elf_backend_data (output_bfd);
1377 htab = elf_x86_hash_table (info, bed->target_id);
1378 if (htab == NULL)
1379 return htab;
1380
1381 dynobj = htab->elf.dynobj;
1382 sdyn = bfd_get_linker_section (dynobj, ".dynamic");
1383
1384 /* GOT is always created in setup_gnu_properties. But it may not be
1385 needed. .got.plt section may be needed for static IFUNC. */
1386 if (htab->elf.sgotplt && htab->elf.sgotplt->size > 0)
1387 {
1388 bfd_vma dynamic_addr;
1389
1390 if (bfd_is_abs_section (htab->elf.sgotplt->output_section))
1391 {
1392 _bfd_error_handler
1393 (_("discarded output section: `%pA'"), htab->elf.sgotplt);
1394 return NULL;
1395 }
1396
1397 elf_section_data (htab->elf.sgotplt->output_section)->this_hdr.sh_entsize
1398 = htab->got_entry_size;
1399
1400 dynamic_addr = (sdyn == NULL
1401 ? (bfd_vma) 0
1402 : sdyn->output_section->vma + sdyn->output_offset);
1403
1404 /* Set the first entry in the global offset table to the address
1405 of the dynamic section. Write GOT[1] and GOT[2], needed for
1406 the dynamic linker. */
1407 if (htab->got_entry_size == 8)
1408 {
1409 bfd_put_64 (output_bfd, dynamic_addr,
1410 htab->elf.sgotplt->contents);
1411 bfd_put_64 (output_bfd, (bfd_vma) 0,
1412 htab->elf.sgotplt->contents + 8);
1413 bfd_put_64 (output_bfd, (bfd_vma) 0,
1414 htab->elf.sgotplt->contents + 8*2);
1415 }
1416 else
1417 {
1418 bfd_put_32 (output_bfd, dynamic_addr,
1419 htab->elf.sgotplt->contents);
1420 bfd_put_32 (output_bfd, 0,
1421 htab->elf.sgotplt->contents + 4);
1422 bfd_put_32 (output_bfd, 0,
1423 htab->elf.sgotplt->contents + 4*2);
1424 }
1425 }
1426
1427 if (!htab->elf.dynamic_sections_created)
1428 return htab;
1429
1430 if (sdyn == NULL || htab->elf.sgot == NULL)
1431 abort ();
1432
1433 sizeof_dyn = bed->s->sizeof_dyn;
1434 dyncon = sdyn->contents;
1435 dynconend = sdyn->contents + sdyn->size;
1436 for (; dyncon < dynconend; dyncon += sizeof_dyn)
1437 {
1438 Elf_Internal_Dyn dyn;
1439 asection *s;
1440
1441 (*bed->s->swap_dyn_in) (dynobj, dyncon, &dyn);
1442
1443 switch (dyn.d_tag)
1444 {
1445 default:
1446 if (htab->elf.target_os == is_vxworks
1447 && elf_vxworks_finish_dynamic_entry (output_bfd, &dyn))
1448 break;
1449 continue;
1450
1451 case DT_PLTGOT:
1452 s = htab->elf.sgotplt;
1453 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
1454 break;
1455
1456 case DT_JMPREL:
1457 dyn.d_un.d_ptr = htab->elf.srelplt->output_section->vma;
1458 break;
1459
1460 case DT_PLTRELSZ:
1461 s = htab->elf.srelplt->output_section;
1462 dyn.d_un.d_val = s->size;
1463 break;
1464
1465 case DT_TLSDESC_PLT:
1466 s = htab->elf.splt;
1467 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
1468 + htab->elf.tlsdesc_plt;
1469 break;
1470
1471 case DT_TLSDESC_GOT:
1472 s = htab->elf.sgot;
1473 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
1474 + htab->elf.tlsdesc_got;
1475 break;
1476 }
1477
1478 (*bed->s->swap_dyn_out) (output_bfd, &dyn, dyncon);
1479 }
1480
1481 if (htab->plt_got != NULL && htab->plt_got->size > 0)
1482 elf_section_data (htab->plt_got->output_section)
1483 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size;
1484
1485 if (htab->plt_second != NULL && htab->plt_second->size > 0)
1486 elf_section_data (htab->plt_second->output_section)
1487 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size;
1488
1489 /* Adjust .eh_frame for .plt section. */
1490 if (htab->plt_eh_frame != NULL
1491 && htab->plt_eh_frame->contents != NULL)
1492 {
1493 if (htab->elf.splt != NULL
1494 && htab->elf.splt->size != 0
1495 && (htab->elf.splt->flags & SEC_EXCLUDE) == 0
1496 && htab->elf.splt->output_section != NULL
1497 && htab->plt_eh_frame->output_section != NULL)
1498 {
1499 bfd_vma plt_start = htab->elf.splt->output_section->vma;
1500 bfd_vma eh_frame_start = htab->plt_eh_frame->output_section->vma
1501 + htab->plt_eh_frame->output_offset
1502 + PLT_FDE_START_OFFSET;
1503 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1504 htab->plt_eh_frame->contents
1505 + PLT_FDE_START_OFFSET);
1506 }
1507
1508 if (htab->plt_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
1509 {
1510 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1511 htab->plt_eh_frame,
1512 htab->plt_eh_frame->contents))
1513 return NULL;
1514 }
1515 }
1516
1517 /* Adjust .eh_frame for .plt.got section. */
1518 if (htab->plt_got_eh_frame != NULL
1519 && htab->plt_got_eh_frame->contents != NULL)
1520 {
1521 if (htab->plt_got != NULL
1522 && htab->plt_got->size != 0
1523 && (htab->plt_got->flags & SEC_EXCLUDE) == 0
1524 && htab->plt_got->output_section != NULL
1525 && htab->plt_got_eh_frame->output_section != NULL)
1526 {
1527 bfd_vma plt_start = htab->plt_got->output_section->vma;
1528 bfd_vma eh_frame_start = htab->plt_got_eh_frame->output_section->vma
1529 + htab->plt_got_eh_frame->output_offset
1530 + PLT_FDE_START_OFFSET;
1531 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1532 htab->plt_got_eh_frame->contents
1533 + PLT_FDE_START_OFFSET);
1534 }
1535 if (htab->plt_got_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
1536 {
1537 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1538 htab->plt_got_eh_frame,
1539 htab->plt_got_eh_frame->contents))
1540 return NULL;
1541 }
1542 }
1543
1544 /* Adjust .eh_frame for the second PLT section. */
1545 if (htab->plt_second_eh_frame != NULL
1546 && htab->plt_second_eh_frame->contents != NULL)
1547 {
1548 if (htab->plt_second != NULL
1549 && htab->plt_second->size != 0
1550 && (htab->plt_second->flags & SEC_EXCLUDE) == 0
1551 && htab->plt_second->output_section != NULL
1552 && htab->plt_second_eh_frame->output_section != NULL)
1553 {
1554 bfd_vma plt_start = htab->plt_second->output_section->vma;
1555 bfd_vma eh_frame_start
1556 = (htab->plt_second_eh_frame->output_section->vma
1557 + htab->plt_second_eh_frame->output_offset
1558 + PLT_FDE_START_OFFSET);
1559 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1560 htab->plt_second_eh_frame->contents
1561 + PLT_FDE_START_OFFSET);
1562 }
1563 if (htab->plt_second_eh_frame->sec_info_type
1564 == SEC_INFO_TYPE_EH_FRAME)
1565 {
1566 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1567 htab->plt_second_eh_frame,
1568 htab->plt_second_eh_frame->contents))
1569 return NULL;
1570 }
1571 }
1572
1573 if (htab->elf.sgot && htab->elf.sgot->size > 0)
1574 elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize
1575 = htab->got_entry_size;
1576
1577 return htab;
1578 }
1579
1580
1581 bfd_boolean
1582 _bfd_x86_elf_always_size_sections (bfd *output_bfd,
1583 struct bfd_link_info *info)
1584 {
1585 asection *tls_sec = elf_hash_table (info)->tls_sec;
1586
1587 if (tls_sec)
1588 {
1589 struct elf_link_hash_entry *tlsbase;
1590
1591 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1592 "_TLS_MODULE_BASE_",
1593 FALSE, FALSE, FALSE);
1594
1595 if (tlsbase && tlsbase->type == STT_TLS)
1596 {
1597 struct elf_x86_link_hash_table *htab;
1598 struct bfd_link_hash_entry *bh = NULL;
1599 const struct elf_backend_data *bed
1600 = get_elf_backend_data (output_bfd);
1601
1602 htab = elf_x86_hash_table (info, bed->target_id);
1603 if (htab == NULL)
1604 return FALSE;
1605
1606 if (!(_bfd_generic_link_add_one_symbol
1607 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1608 tls_sec, 0, NULL, FALSE,
1609 bed->collect, &bh)))
1610 return FALSE;
1611
1612 htab->tls_module_base = bh;
1613
1614 tlsbase = (struct elf_link_hash_entry *)bh;
1615 tlsbase->def_regular = 1;
1616 tlsbase->other = STV_HIDDEN;
1617 tlsbase->root.linker_def = 1;
1618 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
1619 }
1620 }
1621
1622 return TRUE;
1623 }
1624
1625 void
1626 _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h,
1627 const Elf_Internal_Sym *isym,
1628 bfd_boolean definition,
1629 bfd_boolean dynamic ATTRIBUTE_UNUSED)
1630 {
1631 if (definition)
1632 {
1633 struct elf_x86_link_hash_entry *eh
1634 = (struct elf_x86_link_hash_entry *) h;
1635 eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other)
1636 == STV_PROTECTED);
1637 }
1638 }
1639
1640 /* Copy the extra info we tack onto an elf_link_hash_entry. */
1641
1642 void
1643 _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info,
1644 struct elf_link_hash_entry *dir,
1645 struct elf_link_hash_entry *ind)
1646 {
1647 struct elf_x86_link_hash_entry *edir, *eind;
1648
1649 edir = (struct elf_x86_link_hash_entry *) dir;
1650 eind = (struct elf_x86_link_hash_entry *) ind;
1651
1652 if (ind->root.type == bfd_link_hash_indirect
1653 && dir->got.refcount <= 0)
1654 {
1655 edir->tls_type = eind->tls_type;
1656 eind->tls_type = GOT_UNKNOWN;
1657 }
1658
1659 /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will
1660 generate a R_386_COPY reloc. */
1661 edir->gotoff_ref |= eind->gotoff_ref;
1662
1663 edir->zero_undefweak |= eind->zero_undefweak;
1664
1665 if (ELIMINATE_COPY_RELOCS
1666 && ind->root.type != bfd_link_hash_indirect
1667 && dir->dynamic_adjusted)
1668 {
1669 /* If called to transfer flags for a weakdef during processing
1670 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
1671 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
1672 if (dir->versioned != versioned_hidden)
1673 dir->ref_dynamic |= ind->ref_dynamic;
1674 dir->ref_regular |= ind->ref_regular;
1675 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
1676 dir->needs_plt |= ind->needs_plt;
1677 dir->pointer_equality_needed |= ind->pointer_equality_needed;
1678 }
1679 else
1680 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
1681 }
1682
1683 /* Remove undefined weak symbol from the dynamic symbol table if it
1684 is resolved to 0. */
1685
1686 bfd_boolean
1687 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
1688 struct elf_link_hash_entry *h)
1689 {
1690 if (h->dynindx != -1
1691 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h)))
1692 {
1693 h->dynindx = -1;
1694 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
1695 h->dynstr_index);
1696 }
1697 return TRUE;
1698 }
1699
1700 /* Change the STT_GNU_IFUNC symbol defined in position-dependent
1701 executable into the normal function symbol and set its address
1702 to its PLT entry, which should be resolved by R_*_IRELATIVE at
1703 run-time. */
1704
1705 void
1706 _bfd_x86_elf_link_fixup_ifunc_symbol (struct bfd_link_info *info,
1707 struct elf_x86_link_hash_table *htab,
1708 struct elf_link_hash_entry *h,
1709 Elf_Internal_Sym *sym)
1710 {
1711 if (bfd_link_pde (info)
1712 && h->def_regular
1713 && h->dynindx != -1
1714 && h->plt.offset != (bfd_vma) -1
1715 && h->type == STT_GNU_IFUNC
1716 && h->pointer_equality_needed)
1717 {
1718 asection *plt_s;
1719 bfd_vma plt_offset;
1720 bfd *output_bfd = info->output_bfd;
1721
1722 if (htab->plt_second)
1723 {
1724 struct elf_x86_link_hash_entry *eh
1725 = (struct elf_x86_link_hash_entry *) h;
1726
1727 plt_s = htab->plt_second;
1728 plt_offset = eh->plt_second.offset;
1729 }
1730 else
1731 {
1732 plt_s = htab->elf.splt;
1733 plt_offset = h->plt.offset;
1734 }
1735
1736 sym->st_size = 0;
1737 sym->st_info = ELF_ST_INFO (ELF_ST_BIND (sym->st_info), STT_FUNC);
1738 sym->st_shndx
1739 = _bfd_elf_section_from_bfd_section (output_bfd,
1740 plt_s->output_section);
1741 sym->st_value = (plt_s->output_section->vma
1742 + plt_s->output_offset + plt_offset);
1743 }
1744 }
1745
1746 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1747
1748 bfd_boolean
1749 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1750 {
1751 if (h->plt.offset != (bfd_vma) -1
1752 && !h->def_regular
1753 && !h->pointer_equality_needed)
1754 return FALSE;
1755
1756 return _bfd_elf_hash_symbol (h);
1757 }
1758
1759 /* Adjust a symbol defined by a dynamic object and referenced by a
1760 regular object. The current definition is in some section of the
1761 dynamic object, but we're not including those sections. We have to
1762 change the definition to something the rest of the link can
1763 understand. */
1764
1765 bfd_boolean
1766 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1767 struct elf_link_hash_entry *h)
1768 {
1769 struct elf_x86_link_hash_table *htab;
1770 asection *s, *srel;
1771 struct elf_x86_link_hash_entry *eh;
1772 struct elf_dyn_relocs *p;
1773 const struct elf_backend_data *bed
1774 = get_elf_backend_data (info->output_bfd);
1775
1776 /* STT_GNU_IFUNC symbol must go through PLT. */
1777 if (h->type == STT_GNU_IFUNC)
1778 {
1779 /* All local STT_GNU_IFUNC references must be treate as local
1780 calls via local PLT. */
1781 if (h->ref_regular
1782 && SYMBOL_CALLS_LOCAL (info, h))
1783 {
1784 bfd_size_type pc_count = 0, count = 0;
1785 struct elf_dyn_relocs **pp;
1786
1787 eh = (struct elf_x86_link_hash_entry *) h;
1788 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
1789 {
1790 pc_count += p->pc_count;
1791 p->count -= p->pc_count;
1792 p->pc_count = 0;
1793 count += p->count;
1794 if (p->count == 0)
1795 *pp = p->next;
1796 else
1797 pp = &p->next;
1798 }
1799
1800 if (pc_count || count)
1801 {
1802 h->non_got_ref = 1;
1803 if (pc_count)
1804 {
1805 /* Increment PLT reference count only for PC-relative
1806 references. */
1807 h->needs_plt = 1;
1808 if (h->plt.refcount <= 0)
1809 h->plt.refcount = 1;
1810 else
1811 h->plt.refcount += 1;
1812 }
1813 }
1814 }
1815
1816 if (h->plt.refcount <= 0)
1817 {
1818 h->plt.offset = (bfd_vma) -1;
1819 h->needs_plt = 0;
1820 }
1821 return TRUE;
1822 }
1823
1824 /* If this is a function, put it in the procedure linkage table. We
1825 will fill in the contents of the procedure linkage table later,
1826 when we know the address of the .got section. */
1827 if (h->type == STT_FUNC
1828 || h->needs_plt)
1829 {
1830 if (h->plt.refcount <= 0
1831 || SYMBOL_CALLS_LOCAL (info, h)
1832 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1833 && h->root.type == bfd_link_hash_undefweak))
1834 {
1835 /* This case can occur if we saw a PLT32 reloc in an input
1836 file, but the symbol was never referred to by a dynamic
1837 object, or if all references were garbage collected. In
1838 such a case, we don't actually need to build a procedure
1839 linkage table, and we can just do a PC32 reloc instead. */
1840 h->plt.offset = (bfd_vma) -1;
1841 h->needs_plt = 0;
1842 }
1843
1844 return TRUE;
1845 }
1846 else
1847 /* It's possible that we incorrectly decided a .plt reloc was needed
1848 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
1849 check_relocs. We can't decide accurately between function and
1850 non-function syms in check-relocs; Objects loaded later in
1851 the link may change h->type. So fix it now. */
1852 h->plt.offset = (bfd_vma) -1;
1853
1854 eh = (struct elf_x86_link_hash_entry *) h;
1855
1856 /* If this is a weak symbol, and there is a real definition, the
1857 processor independent code will have arranged for us to see the
1858 real definition first, and we can just use the same value. */
1859 if (h->is_weakalias)
1860 {
1861 struct elf_link_hash_entry *def = weakdef (h);
1862 BFD_ASSERT (def->root.type == bfd_link_hash_defined);
1863 h->root.u.def.section = def->root.u.def.section;
1864 h->root.u.def.value = def->root.u.def.value;
1865 if (ELIMINATE_COPY_RELOCS
1866 || info->nocopyreloc
1867 || SYMBOL_NO_COPYRELOC (info, eh))
1868 {
1869 /* NB: needs_copy is always 0 for i386. */
1870 h->non_got_ref = def->non_got_ref;
1871 eh->needs_copy = def->needs_copy;
1872 }
1873 return TRUE;
1874 }
1875
1876 /* This is a reference to a symbol defined by a dynamic object which
1877 is not a function. */
1878
1879 /* If we are creating a shared library, we must presume that the
1880 only references to the symbol are via the global offset table.
1881 For such cases we need not do anything here; the relocations will
1882 be handled correctly by relocate_section. */
1883 if (!bfd_link_executable (info))
1884 return TRUE;
1885
1886 /* If there are no references to this symbol that do not use the
1887 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
1888 reloc. NB: gotoff_ref is always 0 for x86-64. */
1889 if (!h->non_got_ref && !eh->gotoff_ref)
1890 return TRUE;
1891
1892 /* If -z nocopyreloc was given, we won't generate them either. */
1893 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
1894 {
1895 h->non_got_ref = 0;
1896 return TRUE;
1897 }
1898
1899 htab = elf_x86_hash_table (info, bed->target_id);
1900 if (htab == NULL)
1901 return FALSE;
1902
1903 /* If there aren't any dynamic relocs in read-only sections nor
1904 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
1905 avoid the copy reloc. This doesn't work on VxWorks, where we can
1906 not have dynamic relocations (other than copy and jump slot
1907 relocations) in an executable. */
1908 if (ELIMINATE_COPY_RELOCS
1909 && (bed->target_id == X86_64_ELF_DATA
1910 || (!eh->gotoff_ref
1911 && htab->elf.target_os != is_vxworks)))
1912 {
1913 /* If we don't find any dynamic relocs in read-only sections,
1914 then we'll be keeping the dynamic relocs and avoiding the copy
1915 reloc. */
1916 if (!_bfd_elf_readonly_dynrelocs (h))
1917 {
1918 h->non_got_ref = 0;
1919 return TRUE;
1920 }
1921 }
1922
1923 /* We must allocate the symbol in our .dynbss section, which will
1924 become part of the .bss section of the executable. There will be
1925 an entry for this symbol in the .dynsym section. The dynamic
1926 object will contain position independent code, so all references
1927 from the dynamic object to this symbol will go through the global
1928 offset table. The dynamic linker will use the .dynsym entry to
1929 determine the address it must put in the global offset table, so
1930 both the dynamic object and the regular object will refer to the
1931 same memory location for the variable. */
1932
1933 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
1934 dynamic linker to copy the initial value out of the dynamic object
1935 and into the runtime process image. */
1936 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
1937 {
1938 s = htab->elf.sdynrelro;
1939 srel = htab->elf.sreldynrelro;
1940 }
1941 else
1942 {
1943 s = htab->elf.sdynbss;
1944 srel = htab->elf.srelbss;
1945 }
1946 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
1947 {
1948 srel->size += htab->sizeof_reloc;
1949 h->needs_copy = 1;
1950 }
1951
1952 return _bfd_elf_adjust_dynamic_copy (info, h, s);
1953 }
1954
1955 void
1956 _bfd_x86_elf_hide_symbol (struct bfd_link_info *info,
1957 struct elf_link_hash_entry *h,
1958 bfd_boolean force_local)
1959 {
1960 if (h->root.type == bfd_link_hash_undefweak
1961 && info->nointerp
1962 && bfd_link_pie (info))
1963 {
1964 /* When there is no dynamic interpreter in PIE, make the undefined
1965 weak symbol dynamic so that PC relative branch to the undefined
1966 weak symbol will land to address 0. */
1967 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1968 if (h->plt.refcount > 0
1969 || eh->plt_got.refcount > 0)
1970 return;
1971 }
1972
1973 _bfd_elf_link_hash_hide_symbol (info, h, force_local);
1974 }
1975
1976 /* Return TRUE if a symbol is referenced locally. It is similar to
1977 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
1978 works in check_relocs. */
1979
1980 bfd_boolean
1981 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
1982 struct elf_link_hash_entry *h)
1983 {
1984 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1985 struct elf_x86_link_hash_table *htab
1986 = (struct elf_x86_link_hash_table *) info->hash;
1987
1988 if (eh->local_ref > 1)
1989 return TRUE;
1990
1991 if (eh->local_ref == 1)
1992 return FALSE;
1993
1994 /* Unversioned symbols defined in regular objects can be forced local
1995 by linker version script. A weak undefined symbol is forced local
1996 if
1997 1. It has non-default visibility. Or
1998 2. When building executable, there is no dynamic linker. Or
1999 3. or "-z nodynamic-undefined-weak" is used.
2000 */
2001 if (SYMBOL_REFERENCES_LOCAL (info, h)
2002 || (h->root.type == bfd_link_hash_undefweak
2003 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
2004 || (bfd_link_executable (info)
2005 && htab->interp == NULL)
2006 || info->dynamic_undefined_weak == 0))
2007 || ((h->def_regular || ELF_COMMON_DEF_P (h))
2008 && info->version_info != NULL
2009 && _bfd_elf_link_hide_sym_by_version (info, h)))
2010 {
2011 eh->local_ref = 2;
2012 return TRUE;
2013 }
2014
2015 eh->local_ref = 1;
2016 return FALSE;
2017 }
2018
2019 /* Return the section that should be marked against GC for a given
2020 relocation. */
2021
2022 asection *
2023 _bfd_x86_elf_gc_mark_hook (asection *sec,
2024 struct bfd_link_info *info,
2025 Elf_Internal_Rela *rel,
2026 struct elf_link_hash_entry *h,
2027 Elf_Internal_Sym *sym)
2028 {
2029 /* Compiler should optimize this out. */
2030 if (((unsigned int) R_X86_64_GNU_VTINHERIT
2031 != (unsigned int) R_386_GNU_VTINHERIT)
2032 || ((unsigned int) R_X86_64_GNU_VTENTRY
2033 != (unsigned int) R_386_GNU_VTENTRY))
2034 abort ();
2035
2036 if (h != NULL)
2037 switch (ELF32_R_TYPE (rel->r_info))
2038 {
2039 case R_X86_64_GNU_VTINHERIT:
2040 case R_X86_64_GNU_VTENTRY:
2041 return NULL;
2042 }
2043
2044 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
2045 }
2046
2047 static bfd_vma
2048 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
2049 bfd_vma off,
2050 bfd_vma offset ATTRIBUTE_UNUSED,
2051 bfd_vma got_addr)
2052 {
2053 return got_addr + off;
2054 }
2055
2056 static bfd_vma
2057 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
2058 bfd_vma off,
2059 bfd_vma offset,
2060 bfd_vma got_addr ATTRIBUTE_UNUSED)
2061 {
2062 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
2063 }
2064
2065 static bfd_boolean
2066 elf_i386_valid_plt_reloc_p (unsigned int type)
2067 {
2068 return (type == R_386_JUMP_SLOT
2069 || type == R_386_GLOB_DAT
2070 || type == R_386_IRELATIVE);
2071 }
2072
2073 static bfd_boolean
2074 elf_x86_64_valid_plt_reloc_p (unsigned int type)
2075 {
2076 return (type == R_X86_64_JUMP_SLOT
2077 || type == R_X86_64_GLOB_DAT
2078 || type == R_X86_64_IRELATIVE);
2079 }
2080
2081 long
2082 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
2083 long count,
2084 long relsize,
2085 bfd_vma got_addr,
2086 struct elf_x86_plt plts[],
2087 asymbol **dynsyms,
2088 asymbol **ret)
2089 {
2090 long size, i, n, len;
2091 int j;
2092 unsigned int plt_got_offset, plt_entry_size;
2093 asymbol *s;
2094 bfd_byte *plt_contents;
2095 long dynrelcount;
2096 arelent **dynrelbuf, *p;
2097 char *names;
2098 const struct elf_backend_data *bed;
2099 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
2100 bfd_vma);
2101 bfd_boolean (*valid_plt_reloc_p) (unsigned int);
2102
2103 dynrelbuf = NULL;
2104 if (count == 0)
2105 goto bad_return;
2106
2107 dynrelbuf = (arelent **) bfd_malloc (relsize);
2108 if (dynrelbuf == NULL)
2109 goto bad_return;
2110
2111 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
2112 dynsyms);
2113 if (dynrelcount <= 0)
2114 goto bad_return;
2115
2116 /* Sort the relocs by address. */
2117 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
2118 _bfd_x86_elf_compare_relocs);
2119
2120 size = count * sizeof (asymbol);
2121
2122 /* Allocate space for @plt suffixes. */
2123 n = 0;
2124 for (i = 0; i < dynrelcount; i++)
2125 {
2126 p = dynrelbuf[i];
2127 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
2128 if (p->addend != 0)
2129 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
2130 }
2131
2132 s = *ret = (asymbol *) bfd_zmalloc (size);
2133 if (s == NULL)
2134 goto bad_return;
2135
2136 bed = get_elf_backend_data (abfd);
2137
2138 if (bed->target_id == X86_64_ELF_DATA)
2139 {
2140 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
2141 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
2142 }
2143 else
2144 {
2145 get_plt_got_vma = elf_i386_get_plt_got_vma;
2146 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
2147 if (got_addr)
2148 {
2149 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
2150 address. */
2151 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
2152 if (sec != NULL)
2153 got_addr = sec->vma;
2154 else
2155 {
2156 sec = bfd_get_section_by_name (abfd, ".got");
2157 if (sec != NULL)
2158 got_addr = sec->vma;
2159 }
2160
2161 if (got_addr == (bfd_vma) -1)
2162 goto bad_return;
2163 }
2164 }
2165
2166 /* Check for each PLT section. */
2167 names = (char *) (s + count);
2168 size = 0;
2169 n = 0;
2170 for (j = 0; plts[j].name != NULL; j++)
2171 if ((plt_contents = plts[j].contents) != NULL)
2172 {
2173 long k;
2174 bfd_vma offset;
2175 asection *plt;
2176 struct elf_x86_plt *plt_p = &plts[j];
2177
2178 plt_got_offset = plt_p->plt_got_offset;
2179 plt_entry_size = plt_p->plt_entry_size;
2180
2181 plt = plt_p->sec;
2182
2183 if ((plt_p->type & plt_lazy))
2184 {
2185 /* Skip PLT0 in lazy PLT. */
2186 k = 1;
2187 offset = plt_entry_size;
2188 }
2189 else
2190 {
2191 k = 0;
2192 offset = 0;
2193 }
2194
2195 /* Check each PLT entry against dynamic relocations. */
2196 for (; k < plt_p->count; k++)
2197 {
2198 int off;
2199 bfd_vma got_vma;
2200 long min, max, mid;
2201
2202 /* Get the GOT offset for i386 or the PC-relative offset
2203 for x86-64, a signed 32-bit integer. */
2204 off = H_GET_32 (abfd, (plt_contents + offset
2205 + plt_got_offset));
2206 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
2207
2208 /* Binary search. */
2209 p = dynrelbuf[0];
2210 min = 0;
2211 max = dynrelcount;
2212 while ((min + 1) < max)
2213 {
2214 arelent *r;
2215
2216 mid = (min + max) / 2;
2217 r = dynrelbuf[mid];
2218 if (got_vma > r->address)
2219 min = mid;
2220 else if (got_vma < r->address)
2221 max = mid;
2222 else
2223 {
2224 p = r;
2225 break;
2226 }
2227 }
2228
2229 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
2230 if (got_vma == p->address
2231 && p->howto != NULL
2232 && valid_plt_reloc_p (p->howto->type))
2233 {
2234 *s = **p->sym_ptr_ptr;
2235 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
2236 set. Since we are defining a symbol, ensure one
2237 of them is set. */
2238 if ((s->flags & BSF_LOCAL) == 0)
2239 s->flags |= BSF_GLOBAL;
2240 s->flags |= BSF_SYNTHETIC;
2241 /* This is no longer a section symbol. */
2242 s->flags &= ~BSF_SECTION_SYM;
2243 s->section = plt;
2244 s->the_bfd = plt->owner;
2245 s->value = offset;
2246 s->udata.p = NULL;
2247 s->name = names;
2248 len = strlen ((*p->sym_ptr_ptr)->name);
2249 memcpy (names, (*p->sym_ptr_ptr)->name, len);
2250 names += len;
2251 if (p->addend != 0)
2252 {
2253 char buf[30], *a;
2254
2255 memcpy (names, "+0x", sizeof ("+0x") - 1);
2256 names += sizeof ("+0x") - 1;
2257 bfd_sprintf_vma (abfd, buf, p->addend);
2258 for (a = buf; *a == '0'; ++a)
2259 ;
2260 size = strlen (a);
2261 memcpy (names, a, size);
2262 names += size;
2263 }
2264 memcpy (names, "@plt", sizeof ("@plt"));
2265 names += sizeof ("@plt");
2266 n++;
2267 s++;
2268 /* There should be only one entry in PLT for a given
2269 symbol. Set howto to NULL after processing a PLT
2270 entry to guard against corrupted PLT. */
2271 p->howto = NULL;
2272 }
2273 offset += plt_entry_size;
2274 }
2275 }
2276
2277 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
2278 if (n == 0)
2279 {
2280 bad_return:
2281 count = -1;
2282 }
2283 else
2284 count = n;
2285
2286 for (j = 0; plts[j].name != NULL; j++)
2287 free (plts[j].contents);
2288
2289 free (dynrelbuf);
2290
2291 return count;
2292 }
2293
2294 /* Parse x86 GNU properties. */
2295
2296 enum elf_property_kind
2297 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
2298 bfd_byte *ptr, unsigned int datasz)
2299 {
2300 elf_property *prop;
2301
2302 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2303 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2304 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
2305 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2306 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
2307 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
2308 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2309 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2310 {
2311 if (datasz != 4)
2312 {
2313 _bfd_error_handler
2314 (_("error: %pB: <corrupt x86 property (0x%x) size: 0x%x>"),
2315 abfd, type, datasz);
2316 return property_corrupt;
2317 }
2318 prop = _bfd_elf_get_property (abfd, type, datasz);
2319 prop->u.number |= bfd_h_get_32 (abfd, ptr);
2320 prop->pr_kind = property_number;
2321 return property_number;
2322 }
2323
2324 return property_ignored;
2325 }
2326
2327 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2328 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2329 should be merged with ABFD. */
2330
2331 bfd_boolean
2332 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2333 bfd *abfd ATTRIBUTE_UNUSED,
2334 bfd *bbfd ATTRIBUTE_UNUSED,
2335 elf_property *aprop,
2336 elf_property *bprop)
2337 {
2338 unsigned int number, features;
2339 bfd_boolean updated = FALSE;
2340 const struct elf_backend_data *bed;
2341 struct elf_x86_link_hash_table *htab;
2342 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2343
2344 if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2345 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2346 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2347 {
2348 if (aprop == NULL || bprop == NULL)
2349 {
2350 /* Only one of APROP and BPROP can be NULL. */
2351 if (aprop != NULL)
2352 {
2353 /* Remove this property since the other input file doesn't
2354 have it. */
2355 aprop->pr_kind = property_remove;
2356 updated = TRUE;
2357 }
2358 }
2359 else
2360 {
2361 number = aprop->u.number;
2362 aprop->u.number = number | bprop->u.number;
2363 updated = number != (unsigned int) aprop->u.number;
2364 }
2365 return updated;
2366 }
2367 else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2368 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_LO
2369 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_HI))
2370 {
2371 features = 0;
2372 if (pr_type == GNU_PROPERTY_X86_ISA_1_NEEDED)
2373 {
2374 bed = get_elf_backend_data (info->output_bfd);
2375 htab = elf_x86_hash_table (info, bed->target_id);
2376 switch (htab->params->isa_level)
2377 {
2378 case 0:
2379 break;
2380 case 2:
2381 features = GNU_PROPERTY_X86_ISA_1_V2;
2382 break;
2383 case 3:
2384 features = GNU_PROPERTY_X86_ISA_1_V3;
2385 break;
2386 case 4:
2387 features = GNU_PROPERTY_X86_ISA_1_V4;
2388 break;
2389 default:
2390 abort ();
2391 }
2392 }
2393 if (aprop != NULL && bprop != NULL)
2394 {
2395 number = aprop->u.number;
2396 aprop->u.number = number | bprop->u.number | features;
2397 /* Remove the property if all bits are empty. */
2398 if (aprop->u.number == 0)
2399 {
2400 aprop->pr_kind = property_remove;
2401 updated = TRUE;
2402 }
2403 else
2404 updated = number != (unsigned int) aprop->u.number;
2405 }
2406 else
2407 {
2408 /* Only one of APROP and BPROP can be NULL. */
2409 if (aprop != NULL)
2410 {
2411 aprop->u.number |= features;
2412 if (aprop->u.number == 0)
2413 {
2414 /* Remove APROP if all bits are empty. */
2415 aprop->pr_kind = property_remove;
2416 updated = TRUE;
2417 }
2418 }
2419 else
2420 {
2421 /* Return TRUE if APROP is NULL and all bits of BPROP
2422 aren't empty to indicate that BPROP should be added
2423 to ABFD. */
2424 bprop->u.number |= features;
2425 updated = bprop->u.number != 0;
2426 }
2427 }
2428 return updated;
2429 }
2430 else if (pr_type >= GNU_PROPERTY_X86_UINT32_AND_LO
2431 && pr_type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2432 {
2433 /* Only one of APROP and BPROP can be NULL:
2434 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2435 2. If APROP is NULL, remove x86 feature.
2436 3. Otherwise, do nothing.
2437 */
2438 bed = get_elf_backend_data (info->output_bfd);
2439 htab = elf_x86_hash_table (info, bed->target_id);
2440 if (!htab)
2441 abort ();
2442 if (aprop != NULL && bprop != NULL)
2443 {
2444 number = aprop->u.number;
2445 aprop->u.number = number & bprop->u.number;
2446 if (pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2447 {
2448 features = 0;
2449 if (htab->params->ibt)
2450 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2451 if (htab->params->shstk)
2452 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2453 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2454 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2455 aprop->u.number |= features;
2456 }
2457 updated = number != (unsigned int) aprop->u.number;
2458 /* Remove the property if all feature bits are cleared. */
2459 if (aprop->u.number == 0)
2460 aprop->pr_kind = property_remove;
2461 }
2462 else
2463 {
2464 /* There should be no AND properties since some input doesn't
2465 have them. Set IBT and SHSTK properties for -z ibt and -z
2466 shstk if needed. */
2467 features = 0;
2468 if (pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2469 {
2470 if (htab->params->ibt)
2471 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2472 if (htab->params->shstk)
2473 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2474 }
2475 if (features)
2476 {
2477 if (aprop != NULL)
2478 {
2479 updated = features != (unsigned int) aprop->u.number;
2480 aprop->u.number = features;
2481 }
2482 else
2483 {
2484 updated = TRUE;
2485 bprop->u.number = features;
2486 }
2487 }
2488 else if (aprop != NULL)
2489 {
2490 aprop->pr_kind = property_remove;
2491 updated = TRUE;
2492 }
2493 }
2494 return updated;
2495 }
2496 else
2497 {
2498 /* Never should happen. */
2499 abort ();
2500 }
2501
2502 return updated;
2503 }
2504
2505 /* Set up x86 GNU properties. Return the first relocatable ELF input
2506 with GNU properties if found. Otherwise, return NULL. */
2507
2508 bfd *
2509 _bfd_x86_elf_link_setup_gnu_properties
2510 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2511 {
2512 bfd_boolean normal_target;
2513 bfd_boolean lazy_plt;
2514 asection *sec, *pltsec;
2515 bfd *dynobj;
2516 bfd_boolean use_ibt_plt;
2517 unsigned int plt_alignment, features, isa_level;
2518 struct elf_x86_link_hash_table *htab;
2519 bfd *pbfd;
2520 bfd *ebfd = NULL;
2521 elf_property *prop;
2522 const struct elf_backend_data *bed;
2523 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2524 unsigned int got_align;
2525
2526 /* Find a normal input file with GNU property note. */
2527 for (pbfd = info->input_bfds;
2528 pbfd != NULL;
2529 pbfd = pbfd->link.next)
2530 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2531 && bfd_count_sections (pbfd) != 0)
2532 {
2533 ebfd = pbfd;
2534
2535 if (elf_properties (pbfd) != NULL)
2536 break;
2537 }
2538
2539 bed = get_elf_backend_data (info->output_bfd);
2540
2541 htab = elf_x86_hash_table (info, bed->target_id);
2542 if (htab == NULL)
2543 return pbfd;
2544
2545 features = 0;
2546 if (htab->params->ibt)
2547 {
2548 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2549 htab->params->cet_report &= ~cet_report_ibt;
2550 }
2551 if (htab->params->shstk)
2552 {
2553 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2554 htab->params->cet_report &= ~cet_report_shstk;
2555 }
2556 if (!(htab->params->cet_report & (cet_report_ibt | cet_report_shstk)))
2557 htab->params->cet_report = cet_report_none;
2558
2559 switch (htab->params->isa_level)
2560 {
2561 case 0:
2562 isa_level = 0;
2563 break;
2564 case 2:
2565 isa_level = GNU_PROPERTY_X86_ISA_1_V2;
2566 break;
2567 case 3:
2568 isa_level = GNU_PROPERTY_X86_ISA_1_V3;
2569 break;
2570 case 4:
2571 isa_level = GNU_PROPERTY_X86_ISA_1_V4;
2572 break;
2573 default:
2574 abort ();
2575 }
2576
2577 if (ebfd != NULL)
2578 {
2579 prop = NULL;
2580 if (features)
2581 {
2582 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
2583 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2584 prop = _bfd_elf_get_property (ebfd,
2585 GNU_PROPERTY_X86_FEATURE_1_AND,
2586 4);
2587 prop->u.number |= features;
2588 prop->pr_kind = property_number;
2589 }
2590
2591 if (isa_level)
2592 {
2593 /* If ISA level is set, add GNU_PROPERTY_X86_ISA_1_NEEDED. */
2594 prop = _bfd_elf_get_property (ebfd,
2595 GNU_PROPERTY_X86_ISA_1_NEEDED,
2596 4);
2597 prop->u.number |= isa_level;
2598 prop->pr_kind = property_number;
2599 }
2600
2601 /* Create the GNU property note section if needed. */
2602 if (prop != NULL && pbfd == NULL)
2603 {
2604 sec = bfd_make_section_with_flags (ebfd,
2605 NOTE_GNU_PROPERTY_SECTION_NAME,
2606 (SEC_ALLOC
2607 | SEC_LOAD
2608 | SEC_IN_MEMORY
2609 | SEC_READONLY
2610 | SEC_HAS_CONTENTS
2611 | SEC_DATA));
2612 if (sec == NULL)
2613 info->callbacks->einfo (_("%F%P: failed to create GNU property section\n"));
2614
2615 if (!bfd_set_section_alignment (sec, class_align))
2616 {
2617 error_alignment:
2618 info->callbacks->einfo (_("%F%pA: failed to align section\n"),
2619 sec);
2620 }
2621
2622 elf_section_type (sec) = SHT_NOTE;
2623 }
2624 }
2625
2626 if (htab->params->cet_report)
2627 {
2628 /* Report missing IBT and SHSTK properties. */
2629 bfd *abfd;
2630 const char *msg;
2631 elf_property_list *p;
2632 bfd_boolean missing_ibt, missing_shstk;
2633 bfd_boolean check_ibt
2634 = !!(htab->params->cet_report & cet_report_ibt);
2635 bfd_boolean check_shstk
2636 = !!(htab->params->cet_report & cet_report_shstk);
2637
2638 if ((htab->params->cet_report & cet_report_warning))
2639 msg = _("%P: %pB: warning: missing %s\n");
2640 else
2641 msg = _("%X%P: %pB: error: missing %s\n");
2642
2643 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
2644 if (!(abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED))
2645 && bfd_get_flavour (abfd) == bfd_target_elf_flavour)
2646 {
2647 for (p = elf_properties (abfd); p; p = p->next)
2648 if (p->property.pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2649 break;
2650
2651 missing_ibt = check_ibt;
2652 missing_shstk = check_shstk;
2653 if (p)
2654 {
2655 missing_ibt &= !(p->property.u.number
2656 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2657 missing_shstk &= !(p->property.u.number
2658 & GNU_PROPERTY_X86_FEATURE_1_SHSTK);
2659 }
2660 if (missing_ibt || missing_shstk)
2661 {
2662 const char *missing;
2663 if (missing_ibt && missing_shstk)
2664 missing = _("IBT and SHSTK properties");
2665 else if (missing_ibt)
2666 missing = _("IBT property");
2667 else
2668 missing = _("SHSTK property");
2669 info->callbacks->einfo (msg, abfd, missing);
2670 }
2671 }
2672 }
2673
2674 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2675
2676 htab->r_info = init_table->r_info;
2677 htab->r_sym = init_table->r_sym;
2678
2679 if (bfd_link_relocatable (info))
2680 return pbfd;
2681
2682 htab->plt0_pad_byte = init_table->plt0_pad_byte;
2683
2684 use_ibt_plt = htab->params->ibtplt || htab->params->ibt;
2685 if (!use_ibt_plt && pbfd != NULL)
2686 {
2687 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2688 elf_property_list *p;
2689
2690 /* The property list is sorted in order of type. */
2691 for (p = elf_properties (pbfd); p; p = p->next)
2692 {
2693 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2694 {
2695 use_ibt_plt = !!(p->property.u.number
2696 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2697 break;
2698 }
2699 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2700 break;
2701 }
2702 }
2703
2704 dynobj = htab->elf.dynobj;
2705
2706 /* Set htab->elf.dynobj here so that there is no need to check and
2707 set it in check_relocs. */
2708 if (dynobj == NULL)
2709 {
2710 if (pbfd != NULL)
2711 {
2712 htab->elf.dynobj = pbfd;
2713 dynobj = pbfd;
2714 }
2715 else
2716 {
2717 bfd *abfd;
2718
2719 /* Find a normal input file to hold linker created
2720 sections. */
2721 for (abfd = info->input_bfds;
2722 abfd != NULL;
2723 abfd = abfd->link.next)
2724 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2725 && (abfd->flags
2726 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
2727 && bed->relocs_compatible (abfd->xvec,
2728 info->output_bfd->xvec))
2729 {
2730 htab->elf.dynobj = abfd;
2731 dynobj = abfd;
2732 break;
2733 }
2734 }
2735 }
2736
2737 /* Return if there are no normal input files. */
2738 if (dynobj == NULL)
2739 return pbfd;
2740
2741 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2742 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2743 canonical function address. */
2744 htab->plt.has_plt0 = 1;
2745 normal_target = htab->elf.target_os == is_normal;
2746
2747 if (normal_target)
2748 {
2749 if (use_ibt_plt)
2750 {
2751 htab->lazy_plt = init_table->lazy_ibt_plt;
2752 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2753 }
2754 else
2755 {
2756 htab->lazy_plt = init_table->lazy_plt;
2757 htab->non_lazy_plt = init_table->non_lazy_plt;
2758 }
2759 }
2760 else
2761 {
2762 htab->lazy_plt = init_table->lazy_plt;
2763 htab->non_lazy_plt = NULL;
2764 }
2765
2766 pltsec = htab->elf.splt;
2767
2768 /* If the non-lazy PLT is available, use it for all PLT entries if
2769 there are no PLT0 or no .plt section. */
2770 if (htab->non_lazy_plt != NULL
2771 && (!htab->plt.has_plt0 || pltsec == NULL))
2772 {
2773 lazy_plt = FALSE;
2774 if (bfd_link_pic (info))
2775 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2776 else
2777 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2778 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2779 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2780 htab->plt.plt_got_insn_size
2781 = htab->non_lazy_plt->plt_got_insn_size;
2782 htab->plt.eh_frame_plt_size
2783 = htab->non_lazy_plt->eh_frame_plt_size;
2784 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2785 }
2786 else
2787 {
2788 lazy_plt = TRUE;
2789 if (bfd_link_pic (info))
2790 {
2791 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2792 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2793 }
2794 else
2795 {
2796 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2797 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2798 }
2799 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2800 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2801 htab->plt.plt_got_insn_size
2802 = htab->lazy_plt->plt_got_insn_size;
2803 htab->plt.eh_frame_plt_size
2804 = htab->lazy_plt->eh_frame_plt_size;
2805 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2806 }
2807
2808 if (htab->elf.target_os == is_vxworks
2809 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2810 &htab->srelplt2))
2811 {
2812 info->callbacks->einfo (_("%F%P: failed to create VxWorks dynamic sections\n"));
2813 return pbfd;
2814 }
2815
2816 /* Since create_dynamic_sections isn't always called, but GOT
2817 relocations need GOT relocations, create them here so that we
2818 don't need to do it in check_relocs. */
2819 if (htab->elf.sgot == NULL
2820 && !_bfd_elf_create_got_section (dynobj, info))
2821 info->callbacks->einfo (_("%F%P: failed to create GOT sections\n"));
2822
2823 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2824
2825 /* Align .got and .got.plt sections to their entry size. Do it here
2826 instead of in create_dynamic_sections so that they are always
2827 properly aligned even if create_dynamic_sections isn't called. */
2828 sec = htab->elf.sgot;
2829 if (!bfd_set_section_alignment (sec, got_align))
2830 goto error_alignment;
2831
2832 sec = htab->elf.sgotplt;
2833 if (!bfd_set_section_alignment (sec, got_align))
2834 goto error_alignment;
2835
2836 /* Create the ifunc sections here so that check_relocs can be
2837 simplified. */
2838 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2839 info->callbacks->einfo (_("%F%P: failed to create ifunc sections\n"));
2840
2841 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2842
2843 if (pltsec != NULL)
2844 {
2845 /* Whe creating executable, set the contents of the .interp
2846 section to the interpreter. */
2847 if (bfd_link_executable (info) && !info->nointerp)
2848 {
2849 asection *s = bfd_get_linker_section (dynobj, ".interp");
2850 if (s == NULL)
2851 abort ();
2852 s->size = htab->dynamic_interpreter_size;
2853 s->contents = (unsigned char *) htab->dynamic_interpreter;
2854 htab->interp = s;
2855 }
2856
2857 if (normal_target)
2858 {
2859 flagword pltflags = (bed->dynamic_sec_flags
2860 | SEC_ALLOC
2861 | SEC_CODE
2862 | SEC_LOAD
2863 | SEC_READONLY);
2864 unsigned int non_lazy_plt_alignment
2865 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2866
2867 sec = pltsec;
2868 if (!bfd_set_section_alignment (sec, plt_alignment))
2869 goto error_alignment;
2870
2871 /* Create the GOT procedure linkage table. */
2872 sec = bfd_make_section_anyway_with_flags (dynobj,
2873 ".plt.got",
2874 pltflags);
2875 if (sec == NULL)
2876 info->callbacks->einfo (_("%F%P: failed to create GOT PLT section\n"));
2877
2878 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
2879 goto error_alignment;
2880
2881 htab->plt_got = sec;
2882
2883 if (lazy_plt)
2884 {
2885 sec = NULL;
2886
2887 if (use_ibt_plt)
2888 {
2889 /* Create the second PLT for Intel IBT support. IBT
2890 PLT is needed only for lazy binding. */
2891 sec = bfd_make_section_anyway_with_flags (dynobj,
2892 ".plt.sec",
2893 pltflags);
2894 if (sec == NULL)
2895 info->callbacks->einfo (_("%F%P: failed to create IBT-enabled PLT section\n"));
2896
2897 if (!bfd_set_section_alignment (sec, plt_alignment))
2898 goto error_alignment;
2899 }
2900 else if (htab->params->bndplt && ABI_64_P (dynobj))
2901 {
2902 /* Create the second PLT for Intel MPX support. MPX
2903 PLT is supported only in 64-bit mode and is needed
2904 only for lazy binding. */
2905 sec = bfd_make_section_anyway_with_flags (dynobj,
2906 ".plt.sec",
2907 pltflags);
2908 if (sec == NULL)
2909 info->callbacks->einfo (_("%F%P: failed to create BND PLT section\n"));
2910
2911 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
2912 goto error_alignment;
2913 }
2914
2915 htab->plt_second = sec;
2916 }
2917 }
2918
2919 if (!info->no_ld_generated_unwind_info)
2920 {
2921 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
2922 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
2923 | SEC_LINKER_CREATED);
2924
2925 sec = bfd_make_section_anyway_with_flags (dynobj,
2926 ".eh_frame",
2927 flags);
2928 if (sec == NULL)
2929 info->callbacks->einfo (_("%F%P: failed to create PLT .eh_frame section\n"));
2930
2931 if (!bfd_set_section_alignment (sec, class_align))
2932 goto error_alignment;
2933
2934 htab->plt_eh_frame = sec;
2935
2936 if (htab->plt_got != NULL)
2937 {
2938 sec = bfd_make_section_anyway_with_flags (dynobj,
2939 ".eh_frame",
2940 flags);
2941 if (sec == NULL)
2942 info->callbacks->einfo (_("%F%P: failed to create GOT PLT .eh_frame section\n"));
2943
2944 if (!bfd_set_section_alignment (sec, class_align))
2945 goto error_alignment;
2946
2947 htab->plt_got_eh_frame = sec;
2948 }
2949
2950 if (htab->plt_second != NULL)
2951 {
2952 sec = bfd_make_section_anyway_with_flags (dynobj,
2953 ".eh_frame",
2954 flags);
2955 if (sec == NULL)
2956 info->callbacks->einfo (_("%F%P: failed to create the second PLT .eh_frame section\n"));
2957
2958 if (!bfd_set_section_alignment (sec, class_align))
2959 goto error_alignment;
2960
2961 htab->plt_second_eh_frame = sec;
2962 }
2963 }
2964 }
2965
2966 /* The .iplt section is used for IFUNC symbols in static
2967 executables. */
2968 sec = htab->elf.iplt;
2969 if (sec != NULL)
2970 {
2971 /* NB: Delay setting its alignment until we know it is non-empty.
2972 Otherwise an empty iplt section may change vma and lma of the
2973 following sections, which triggers moving dot of the following
2974 section backwards, resulting in a warning and section lma not
2975 being set properly. It later leads to a "File truncated"
2976 error. */
2977 if (!bfd_set_section_alignment (sec, 0))
2978 goto error_alignment;
2979
2980 htab->plt.iplt_alignment = (normal_target
2981 ? plt_alignment
2982 : bed->plt_alignment);
2983 }
2984
2985 if (bfd_link_executable (info)
2986 && !info->nointerp
2987 && !htab->params->has_dynamic_linker
2988 && htab->params->static_before_all_inputs)
2989 {
2990 /* Report error for dynamic input objects if -static is passed at
2991 command-line before all input files without --dynamic-linker
2992 unless --no-dynamic-linker is used. */
2993 bfd *abfd;
2994
2995 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
2996 if ((abfd->flags & DYNAMIC))
2997 info->callbacks->einfo
2998 (_("%X%P: attempted static link of dynamic object `%pB'\n"),
2999 abfd);
3000 }
3001
3002 return pbfd;
3003 }
3004
3005 /* Fix up x86 GNU properties. */
3006
3007 void
3008 _bfd_x86_elf_link_fixup_gnu_properties
3009 (struct bfd_link_info *info ATTRIBUTE_UNUSED,
3010 elf_property_list **listp)
3011 {
3012 elf_property_list *p;
3013
3014 for (p = *listp; p; p = p->next)
3015 {
3016 unsigned int type = p->property.pr_type;
3017 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
3018 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3019 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3020 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3021 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3022 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
3023 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
3024 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
3025 {
3026 if (p->property.u.number == 0
3027 && (type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3028 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3029 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3030 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3031 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)))
3032 {
3033 /* Remove empty property. */
3034 *listp = p->next;
3035 continue;
3036 }
3037
3038 listp = &p->next;
3039 }
3040 else if (type > GNU_PROPERTY_HIPROC)
3041 {
3042 /* The property list is sorted in order of type. */
3043 break;
3044 }
3045 }
3046 }
3047
3048 void
3049 _bfd_elf_linker_x86_set_options (struct bfd_link_info * info,
3050 struct elf_linker_x86_params *params)
3051 {
3052 const struct elf_backend_data *bed
3053 = get_elf_backend_data (info->output_bfd);
3054 struct elf_x86_link_hash_table *htab
3055 = elf_x86_hash_table (info, bed->target_id);
3056 if (htab != NULL)
3057 htab->params = params;
3058 }