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1 /* x86 specific support for ELF
2 Copyright (C) 2017-2021 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 unsigned int st_other,
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 (st_other) == STV_PROTECTED;
1636 }
1637 }
1638
1639 /* Copy the extra info we tack onto an elf_link_hash_entry. */
1640
1641 void
1642 _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info,
1643 struct elf_link_hash_entry *dir,
1644 struct elf_link_hash_entry *ind)
1645 {
1646 struct elf_x86_link_hash_entry *edir, *eind;
1647
1648 edir = (struct elf_x86_link_hash_entry *) dir;
1649 eind = (struct elf_x86_link_hash_entry *) ind;
1650
1651 if (ind->root.type == bfd_link_hash_indirect
1652 && dir->got.refcount <= 0)
1653 {
1654 edir->tls_type = eind->tls_type;
1655 eind->tls_type = GOT_UNKNOWN;
1656 }
1657
1658 /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will
1659 generate a R_386_COPY reloc. */
1660 edir->gotoff_ref |= eind->gotoff_ref;
1661
1662 edir->zero_undefweak |= eind->zero_undefweak;
1663
1664 if (ELIMINATE_COPY_RELOCS
1665 && ind->root.type != bfd_link_hash_indirect
1666 && dir->dynamic_adjusted)
1667 {
1668 /* If called to transfer flags for a weakdef during processing
1669 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
1670 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
1671 if (dir->versioned != versioned_hidden)
1672 dir->ref_dynamic |= ind->ref_dynamic;
1673 dir->ref_regular |= ind->ref_regular;
1674 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
1675 dir->needs_plt |= ind->needs_plt;
1676 dir->pointer_equality_needed |= ind->pointer_equality_needed;
1677 }
1678 else
1679 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
1680 }
1681
1682 /* Remove undefined weak symbol from the dynamic symbol table if it
1683 is resolved to 0. */
1684
1685 bfd_boolean
1686 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
1687 struct elf_link_hash_entry *h)
1688 {
1689 if (h->dynindx != -1
1690 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h)))
1691 {
1692 h->dynindx = -1;
1693 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
1694 h->dynstr_index);
1695 }
1696 return TRUE;
1697 }
1698
1699 /* Change the STT_GNU_IFUNC symbol defined in position-dependent
1700 executable into the normal function symbol and set its address
1701 to its PLT entry, which should be resolved by R_*_IRELATIVE at
1702 run-time. */
1703
1704 void
1705 _bfd_x86_elf_link_fixup_ifunc_symbol (struct bfd_link_info *info,
1706 struct elf_x86_link_hash_table *htab,
1707 struct elf_link_hash_entry *h,
1708 Elf_Internal_Sym *sym)
1709 {
1710 if (bfd_link_pde (info)
1711 && h->def_regular
1712 && h->dynindx != -1
1713 && h->plt.offset != (bfd_vma) -1
1714 && h->type == STT_GNU_IFUNC
1715 && h->pointer_equality_needed)
1716 {
1717 asection *plt_s;
1718 bfd_vma plt_offset;
1719 bfd *output_bfd = info->output_bfd;
1720
1721 if (htab->plt_second)
1722 {
1723 struct elf_x86_link_hash_entry *eh
1724 = (struct elf_x86_link_hash_entry *) h;
1725
1726 plt_s = htab->plt_second;
1727 plt_offset = eh->plt_second.offset;
1728 }
1729 else
1730 {
1731 plt_s = htab->elf.splt;
1732 plt_offset = h->plt.offset;
1733 }
1734
1735 sym->st_size = 0;
1736 sym->st_info = ELF_ST_INFO (ELF_ST_BIND (sym->st_info), STT_FUNC);
1737 sym->st_shndx
1738 = _bfd_elf_section_from_bfd_section (output_bfd,
1739 plt_s->output_section);
1740 sym->st_value = (plt_s->output_section->vma
1741 + plt_s->output_offset + plt_offset);
1742 }
1743 }
1744
1745 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1746
1747 bfd_boolean
1748 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1749 {
1750 if (h->plt.offset != (bfd_vma) -1
1751 && !h->def_regular
1752 && !h->pointer_equality_needed)
1753 return FALSE;
1754
1755 return _bfd_elf_hash_symbol (h);
1756 }
1757
1758 /* Adjust a symbol defined by a dynamic object and referenced by a
1759 regular object. The current definition is in some section of the
1760 dynamic object, but we're not including those sections. We have to
1761 change the definition to something the rest of the link can
1762 understand. */
1763
1764 bfd_boolean
1765 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1766 struct elf_link_hash_entry *h)
1767 {
1768 struct elf_x86_link_hash_table *htab;
1769 asection *s, *srel;
1770 struct elf_x86_link_hash_entry *eh;
1771 struct elf_dyn_relocs *p;
1772 const struct elf_backend_data *bed
1773 = get_elf_backend_data (info->output_bfd);
1774
1775 /* STT_GNU_IFUNC symbol must go through PLT. */
1776 if (h->type == STT_GNU_IFUNC)
1777 {
1778 /* All local STT_GNU_IFUNC references must be treate as local
1779 calls via local PLT. */
1780 if (h->ref_regular
1781 && SYMBOL_CALLS_LOCAL (info, h))
1782 {
1783 bfd_size_type pc_count = 0, count = 0;
1784 struct elf_dyn_relocs **pp;
1785
1786 eh = (struct elf_x86_link_hash_entry *) h;
1787 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
1788 {
1789 pc_count += p->pc_count;
1790 p->count -= p->pc_count;
1791 p->pc_count = 0;
1792 count += p->count;
1793 if (p->count == 0)
1794 *pp = p->next;
1795 else
1796 pp = &p->next;
1797 }
1798
1799 if (pc_count || count)
1800 {
1801 h->non_got_ref = 1;
1802 if (pc_count)
1803 {
1804 /* Increment PLT reference count only for PC-relative
1805 references. */
1806 h->needs_plt = 1;
1807 if (h->plt.refcount <= 0)
1808 h->plt.refcount = 1;
1809 else
1810 h->plt.refcount += 1;
1811 }
1812 }
1813 }
1814
1815 if (h->plt.refcount <= 0)
1816 {
1817 h->plt.offset = (bfd_vma) -1;
1818 h->needs_plt = 0;
1819 }
1820 return TRUE;
1821 }
1822
1823 /* If this is a function, put it in the procedure linkage table. We
1824 will fill in the contents of the procedure linkage table later,
1825 when we know the address of the .got section. */
1826 if (h->type == STT_FUNC
1827 || h->needs_plt)
1828 {
1829 if (h->plt.refcount <= 0
1830 || SYMBOL_CALLS_LOCAL (info, h)
1831 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1832 && h->root.type == bfd_link_hash_undefweak))
1833 {
1834 /* This case can occur if we saw a PLT32 reloc in an input
1835 file, but the symbol was never referred to by a dynamic
1836 object, or if all references were garbage collected. In
1837 such a case, we don't actually need to build a procedure
1838 linkage table, and we can just do a PC32 reloc instead. */
1839 h->plt.offset = (bfd_vma) -1;
1840 h->needs_plt = 0;
1841 }
1842
1843 return TRUE;
1844 }
1845 else
1846 /* It's possible that we incorrectly decided a .plt reloc was needed
1847 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
1848 check_relocs. We can't decide accurately between function and
1849 non-function syms in check-relocs; Objects loaded later in
1850 the link may change h->type. So fix it now. */
1851 h->plt.offset = (bfd_vma) -1;
1852
1853 eh = (struct elf_x86_link_hash_entry *) h;
1854
1855 /* If this is a weak symbol, and there is a real definition, the
1856 processor independent code will have arranged for us to see the
1857 real definition first, and we can just use the same value. */
1858 if (h->is_weakalias)
1859 {
1860 struct elf_link_hash_entry *def = weakdef (h);
1861 BFD_ASSERT (def->root.type == bfd_link_hash_defined);
1862 h->root.u.def.section = def->root.u.def.section;
1863 h->root.u.def.value = def->root.u.def.value;
1864 if (ELIMINATE_COPY_RELOCS
1865 || info->nocopyreloc
1866 || SYMBOL_NO_COPYRELOC (info, eh))
1867 {
1868 /* NB: needs_copy is always 0 for i386. */
1869 h->non_got_ref = def->non_got_ref;
1870 eh->needs_copy = def->needs_copy;
1871 }
1872 return TRUE;
1873 }
1874
1875 /* This is a reference to a symbol defined by a dynamic object which
1876 is not a function. */
1877
1878 /* If we are creating a shared library, we must presume that the
1879 only references to the symbol are via the global offset table.
1880 For such cases we need not do anything here; the relocations will
1881 be handled correctly by relocate_section. */
1882 if (!bfd_link_executable (info))
1883 return TRUE;
1884
1885 /* If there are no references to this symbol that do not use the
1886 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
1887 reloc. NB: gotoff_ref is always 0 for x86-64. */
1888 if (!h->non_got_ref && !eh->gotoff_ref)
1889 return TRUE;
1890
1891 /* If -z nocopyreloc was given, we won't generate them either. */
1892 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
1893 {
1894 h->non_got_ref = 0;
1895 return TRUE;
1896 }
1897
1898 htab = elf_x86_hash_table (info, bed->target_id);
1899 if (htab == NULL)
1900 return FALSE;
1901
1902 /* If there aren't any dynamic relocs in read-only sections nor
1903 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
1904 avoid the copy reloc. This doesn't work on VxWorks, where we can
1905 not have dynamic relocations (other than copy and jump slot
1906 relocations) in an executable. */
1907 if (ELIMINATE_COPY_RELOCS
1908 && (bed->target_id == X86_64_ELF_DATA
1909 || (!eh->gotoff_ref
1910 && htab->elf.target_os != is_vxworks)))
1911 {
1912 /* If we don't find any dynamic relocs in read-only sections,
1913 then we'll be keeping the dynamic relocs and avoiding the copy
1914 reloc. */
1915 if (!_bfd_elf_readonly_dynrelocs (h))
1916 {
1917 h->non_got_ref = 0;
1918 return TRUE;
1919 }
1920 }
1921
1922 /* We must allocate the symbol in our .dynbss section, which will
1923 become part of the .bss section of the executable. There will be
1924 an entry for this symbol in the .dynsym section. The dynamic
1925 object will contain position independent code, so all references
1926 from the dynamic object to this symbol will go through the global
1927 offset table. The dynamic linker will use the .dynsym entry to
1928 determine the address it must put in the global offset table, so
1929 both the dynamic object and the regular object will refer to the
1930 same memory location for the variable. */
1931
1932 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
1933 dynamic linker to copy the initial value out of the dynamic object
1934 and into the runtime process image. */
1935 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
1936 {
1937 s = htab->elf.sdynrelro;
1938 srel = htab->elf.sreldynrelro;
1939 }
1940 else
1941 {
1942 s = htab->elf.sdynbss;
1943 srel = htab->elf.srelbss;
1944 }
1945 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
1946 {
1947 srel->size += htab->sizeof_reloc;
1948 h->needs_copy = 1;
1949 }
1950
1951 return _bfd_elf_adjust_dynamic_copy (info, h, s);
1952 }
1953
1954 void
1955 _bfd_x86_elf_hide_symbol (struct bfd_link_info *info,
1956 struct elf_link_hash_entry *h,
1957 bfd_boolean force_local)
1958 {
1959 if (h->root.type == bfd_link_hash_undefweak
1960 && info->nointerp
1961 && bfd_link_pie (info))
1962 {
1963 /* When there is no dynamic interpreter in PIE, make the undefined
1964 weak symbol dynamic so that PC relative branch to the undefined
1965 weak symbol will land to address 0. */
1966 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1967 if (h->plt.refcount > 0
1968 || eh->plt_got.refcount > 0)
1969 return;
1970 }
1971
1972 _bfd_elf_link_hash_hide_symbol (info, h, force_local);
1973 }
1974
1975 /* Return TRUE if a symbol is referenced locally. It is similar to
1976 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
1977 works in check_relocs. */
1978
1979 bfd_boolean
1980 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
1981 struct elf_link_hash_entry *h)
1982 {
1983 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1984 struct elf_x86_link_hash_table *htab
1985 = (struct elf_x86_link_hash_table *) info->hash;
1986
1987 if (eh->local_ref > 1)
1988 return TRUE;
1989
1990 if (eh->local_ref == 1)
1991 return FALSE;
1992
1993 /* Unversioned symbols defined in regular objects can be forced local
1994 by linker version script. A weak undefined symbol is forced local
1995 if
1996 1. It has non-default visibility. Or
1997 2. When building executable, there is no dynamic linker. Or
1998 3. or "-z nodynamic-undefined-weak" is used.
1999 */
2000 if (SYMBOL_REFERENCES_LOCAL (info, h)
2001 || (h->root.type == bfd_link_hash_undefweak
2002 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
2003 || (bfd_link_executable (info)
2004 && htab->interp == NULL)
2005 || info->dynamic_undefined_weak == 0))
2006 || ((h->def_regular || ELF_COMMON_DEF_P (h))
2007 && info->version_info != NULL
2008 && _bfd_elf_link_hide_sym_by_version (info, h)))
2009 {
2010 eh->local_ref = 2;
2011 return TRUE;
2012 }
2013
2014 eh->local_ref = 1;
2015 return FALSE;
2016 }
2017
2018 /* Return the section that should be marked against GC for a given
2019 relocation. */
2020
2021 asection *
2022 _bfd_x86_elf_gc_mark_hook (asection *sec,
2023 struct bfd_link_info *info,
2024 Elf_Internal_Rela *rel,
2025 struct elf_link_hash_entry *h,
2026 Elf_Internal_Sym *sym)
2027 {
2028 /* Compiler should optimize this out. */
2029 if (((unsigned int) R_X86_64_GNU_VTINHERIT
2030 != (unsigned int) R_386_GNU_VTINHERIT)
2031 || ((unsigned int) R_X86_64_GNU_VTENTRY
2032 != (unsigned int) R_386_GNU_VTENTRY))
2033 abort ();
2034
2035 if (h != NULL)
2036 switch (ELF32_R_TYPE (rel->r_info))
2037 {
2038 case R_X86_64_GNU_VTINHERIT:
2039 case R_X86_64_GNU_VTENTRY:
2040 return NULL;
2041 }
2042
2043 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
2044 }
2045
2046 static bfd_vma
2047 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
2048 bfd_vma off,
2049 bfd_vma offset ATTRIBUTE_UNUSED,
2050 bfd_vma got_addr)
2051 {
2052 return got_addr + off;
2053 }
2054
2055 static bfd_vma
2056 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
2057 bfd_vma off,
2058 bfd_vma offset,
2059 bfd_vma got_addr ATTRIBUTE_UNUSED)
2060 {
2061 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
2062 }
2063
2064 static bfd_boolean
2065 elf_i386_valid_plt_reloc_p (unsigned int type)
2066 {
2067 return (type == R_386_JUMP_SLOT
2068 || type == R_386_GLOB_DAT
2069 || type == R_386_IRELATIVE);
2070 }
2071
2072 static bfd_boolean
2073 elf_x86_64_valid_plt_reloc_p (unsigned int type)
2074 {
2075 return (type == R_X86_64_JUMP_SLOT
2076 || type == R_X86_64_GLOB_DAT
2077 || type == R_X86_64_IRELATIVE);
2078 }
2079
2080 long
2081 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
2082 long count,
2083 long relsize,
2084 bfd_vma got_addr,
2085 struct elf_x86_plt plts[],
2086 asymbol **dynsyms,
2087 asymbol **ret)
2088 {
2089 long size, i, n, len;
2090 int j;
2091 unsigned int plt_got_offset, plt_entry_size;
2092 asymbol *s;
2093 bfd_byte *plt_contents;
2094 long dynrelcount;
2095 arelent **dynrelbuf, *p;
2096 char *names;
2097 const struct elf_backend_data *bed;
2098 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
2099 bfd_vma);
2100 bfd_boolean (*valid_plt_reloc_p) (unsigned int);
2101
2102 dynrelbuf = NULL;
2103 if (count == 0)
2104 goto bad_return;
2105
2106 dynrelbuf = (arelent **) bfd_malloc (relsize);
2107 if (dynrelbuf == NULL)
2108 goto bad_return;
2109
2110 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
2111 dynsyms);
2112 if (dynrelcount <= 0)
2113 goto bad_return;
2114
2115 /* Sort the relocs by address. */
2116 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
2117 _bfd_x86_elf_compare_relocs);
2118
2119 size = count * sizeof (asymbol);
2120
2121 /* Allocate space for @plt suffixes. */
2122 n = 0;
2123 for (i = 0; i < dynrelcount; i++)
2124 {
2125 p = dynrelbuf[i];
2126 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
2127 if (p->addend != 0)
2128 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
2129 }
2130
2131 s = *ret = (asymbol *) bfd_zmalloc (size);
2132 if (s == NULL)
2133 goto bad_return;
2134
2135 bed = get_elf_backend_data (abfd);
2136
2137 if (bed->target_id == X86_64_ELF_DATA)
2138 {
2139 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
2140 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
2141 }
2142 else
2143 {
2144 get_plt_got_vma = elf_i386_get_plt_got_vma;
2145 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
2146 if (got_addr)
2147 {
2148 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
2149 address. */
2150 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
2151 if (sec != NULL)
2152 got_addr = sec->vma;
2153 else
2154 {
2155 sec = bfd_get_section_by_name (abfd, ".got");
2156 if (sec != NULL)
2157 got_addr = sec->vma;
2158 }
2159
2160 if (got_addr == (bfd_vma) -1)
2161 goto bad_return;
2162 }
2163 }
2164
2165 /* Check for each PLT section. */
2166 names = (char *) (s + count);
2167 size = 0;
2168 n = 0;
2169 for (j = 0; plts[j].name != NULL; j++)
2170 if ((plt_contents = plts[j].contents) != NULL)
2171 {
2172 long k;
2173 bfd_vma offset;
2174 asection *plt;
2175 struct elf_x86_plt *plt_p = &plts[j];
2176
2177 plt_got_offset = plt_p->plt_got_offset;
2178 plt_entry_size = plt_p->plt_entry_size;
2179
2180 plt = plt_p->sec;
2181
2182 if ((plt_p->type & plt_lazy))
2183 {
2184 /* Skip PLT0 in lazy PLT. */
2185 k = 1;
2186 offset = plt_entry_size;
2187 }
2188 else
2189 {
2190 k = 0;
2191 offset = 0;
2192 }
2193
2194 /* Check each PLT entry against dynamic relocations. */
2195 for (; k < plt_p->count; k++)
2196 {
2197 int off;
2198 bfd_vma got_vma;
2199 long min, max, mid;
2200
2201 /* Get the GOT offset for i386 or the PC-relative offset
2202 for x86-64, a signed 32-bit integer. */
2203 off = H_GET_32 (abfd, (plt_contents + offset
2204 + plt_got_offset));
2205 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
2206
2207 /* Binary search. */
2208 p = dynrelbuf[0];
2209 min = 0;
2210 max = dynrelcount;
2211 while ((min + 1) < max)
2212 {
2213 arelent *r;
2214
2215 mid = (min + max) / 2;
2216 r = dynrelbuf[mid];
2217 if (got_vma > r->address)
2218 min = mid;
2219 else if (got_vma < r->address)
2220 max = mid;
2221 else
2222 {
2223 p = r;
2224 break;
2225 }
2226 }
2227
2228 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
2229 if (got_vma == p->address
2230 && p->howto != NULL
2231 && valid_plt_reloc_p (p->howto->type))
2232 {
2233 *s = **p->sym_ptr_ptr;
2234 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
2235 set. Since we are defining a symbol, ensure one
2236 of them is set. */
2237 if ((s->flags & BSF_LOCAL) == 0)
2238 s->flags |= BSF_GLOBAL;
2239 s->flags |= BSF_SYNTHETIC;
2240 /* This is no longer a section symbol. */
2241 s->flags &= ~BSF_SECTION_SYM;
2242 s->section = plt;
2243 s->the_bfd = plt->owner;
2244 s->value = offset;
2245 s->udata.p = NULL;
2246 s->name = names;
2247 len = strlen ((*p->sym_ptr_ptr)->name);
2248 memcpy (names, (*p->sym_ptr_ptr)->name, len);
2249 names += len;
2250 if (p->addend != 0)
2251 {
2252 char buf[30], *a;
2253
2254 memcpy (names, "+0x", sizeof ("+0x") - 1);
2255 names += sizeof ("+0x") - 1;
2256 bfd_sprintf_vma (abfd, buf, p->addend);
2257 for (a = buf; *a == '0'; ++a)
2258 ;
2259 size = strlen (a);
2260 memcpy (names, a, size);
2261 names += size;
2262 }
2263 memcpy (names, "@plt", sizeof ("@plt"));
2264 names += sizeof ("@plt");
2265 n++;
2266 s++;
2267 /* There should be only one entry in PLT for a given
2268 symbol. Set howto to NULL after processing a PLT
2269 entry to guard against corrupted PLT. */
2270 p->howto = NULL;
2271 }
2272 offset += plt_entry_size;
2273 }
2274 }
2275
2276 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
2277 if (n == 0)
2278 {
2279 bad_return:
2280 count = -1;
2281 }
2282 else
2283 count = n;
2284
2285 for (j = 0; plts[j].name != NULL; j++)
2286 free (plts[j].contents);
2287
2288 free (dynrelbuf);
2289
2290 return count;
2291 }
2292
2293 /* Parse x86 GNU properties. */
2294
2295 enum elf_property_kind
2296 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
2297 bfd_byte *ptr, unsigned int datasz)
2298 {
2299 elf_property *prop;
2300
2301 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2302 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2303 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
2304 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2305 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
2306 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
2307 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2308 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2309 {
2310 if (datasz != 4)
2311 {
2312 _bfd_error_handler
2313 (_("error: %pB: <corrupt x86 property (0x%x) size: 0x%x>"),
2314 abfd, type, datasz);
2315 return property_corrupt;
2316 }
2317 prop = _bfd_elf_get_property (abfd, type, datasz);
2318 prop->u.number |= bfd_h_get_32 (abfd, ptr);
2319 prop->pr_kind = property_number;
2320 return property_number;
2321 }
2322
2323 return property_ignored;
2324 }
2325
2326 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2327 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2328 should be merged with ABFD. */
2329
2330 bfd_boolean
2331 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2332 bfd *abfd ATTRIBUTE_UNUSED,
2333 bfd *bbfd ATTRIBUTE_UNUSED,
2334 elf_property *aprop,
2335 elf_property *bprop)
2336 {
2337 unsigned int number, features;
2338 bfd_boolean updated = FALSE;
2339 const struct elf_backend_data *bed;
2340 struct elf_x86_link_hash_table *htab;
2341 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2342
2343 if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2344 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2345 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2346 {
2347 if (aprop == NULL || bprop == NULL)
2348 {
2349 /* Only one of APROP and BPROP can be NULL. */
2350 if (aprop != NULL)
2351 {
2352 /* Remove this property since the other input file doesn't
2353 have it. */
2354 aprop->pr_kind = property_remove;
2355 updated = TRUE;
2356 }
2357 }
2358 else
2359 {
2360 number = aprop->u.number;
2361 aprop->u.number = number | bprop->u.number;
2362 updated = number != (unsigned int) aprop->u.number;
2363 }
2364 return updated;
2365 }
2366 else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2367 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_LO
2368 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_HI))
2369 {
2370 features = 0;
2371 if (pr_type == GNU_PROPERTY_X86_ISA_1_NEEDED)
2372 {
2373 bed = get_elf_backend_data (info->output_bfd);
2374 htab = elf_x86_hash_table (info, bed->target_id);
2375 switch (htab->params->isa_level)
2376 {
2377 case 0:
2378 break;
2379 case 2:
2380 features = GNU_PROPERTY_X86_ISA_1_V2;
2381 break;
2382 case 3:
2383 features = GNU_PROPERTY_X86_ISA_1_V3;
2384 break;
2385 case 4:
2386 features = GNU_PROPERTY_X86_ISA_1_V4;
2387 break;
2388 default:
2389 abort ();
2390 }
2391 }
2392 if (aprop != NULL && bprop != NULL)
2393 {
2394 number = aprop->u.number;
2395 aprop->u.number = number | bprop->u.number | features;
2396 /* Remove the property if all bits are empty. */
2397 if (aprop->u.number == 0)
2398 {
2399 aprop->pr_kind = property_remove;
2400 updated = TRUE;
2401 }
2402 else
2403 updated = number != (unsigned int) aprop->u.number;
2404 }
2405 else
2406 {
2407 /* Only one of APROP and BPROP can be NULL. */
2408 if (aprop != NULL)
2409 {
2410 aprop->u.number |= features;
2411 if (aprop->u.number == 0)
2412 {
2413 /* Remove APROP if all bits are empty. */
2414 aprop->pr_kind = property_remove;
2415 updated = TRUE;
2416 }
2417 }
2418 else
2419 {
2420 /* Return TRUE if APROP is NULL and all bits of BPROP
2421 aren't empty to indicate that BPROP should be added
2422 to ABFD. */
2423 bprop->u.number |= features;
2424 updated = bprop->u.number != 0;
2425 }
2426 }
2427 return updated;
2428 }
2429 else if (pr_type >= GNU_PROPERTY_X86_UINT32_AND_LO
2430 && pr_type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2431 {
2432 /* Only one of APROP and BPROP can be NULL:
2433 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2434 2. If APROP is NULL, remove x86 feature.
2435 3. Otherwise, do nothing.
2436 */
2437 bed = get_elf_backend_data (info->output_bfd);
2438 htab = elf_x86_hash_table (info, bed->target_id);
2439 if (!htab)
2440 abort ();
2441 if (aprop != NULL && bprop != NULL)
2442 {
2443 number = aprop->u.number;
2444 aprop->u.number = number & bprop->u.number;
2445 if (pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2446 {
2447 features = 0;
2448 if (htab->params->ibt)
2449 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2450 if (htab->params->shstk)
2451 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2452 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2453 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2454 aprop->u.number |= features;
2455 }
2456 updated = number != (unsigned int) aprop->u.number;
2457 /* Remove the property if all feature bits are cleared. */
2458 if (aprop->u.number == 0)
2459 aprop->pr_kind = property_remove;
2460 }
2461 else
2462 {
2463 /* There should be no AND properties since some input doesn't
2464 have them. Set IBT and SHSTK properties for -z ibt and -z
2465 shstk if needed. */
2466 features = 0;
2467 if (pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2468 {
2469 if (htab->params->ibt)
2470 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2471 if (htab->params->shstk)
2472 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2473 }
2474 if (features)
2475 {
2476 if (aprop != NULL)
2477 {
2478 updated = features != (unsigned int) aprop->u.number;
2479 aprop->u.number = features;
2480 }
2481 else
2482 {
2483 updated = TRUE;
2484 bprop->u.number = features;
2485 }
2486 }
2487 else if (aprop != NULL)
2488 {
2489 aprop->pr_kind = property_remove;
2490 updated = TRUE;
2491 }
2492 }
2493 return updated;
2494 }
2495 else
2496 {
2497 /* Never should happen. */
2498 abort ();
2499 }
2500
2501 return updated;
2502 }
2503
2504 /* Set up x86 GNU properties. Return the first relocatable ELF input
2505 with GNU properties if found. Otherwise, return NULL. */
2506
2507 bfd *
2508 _bfd_x86_elf_link_setup_gnu_properties
2509 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2510 {
2511 bfd_boolean normal_target;
2512 bfd_boolean lazy_plt;
2513 asection *sec, *pltsec;
2514 bfd *dynobj;
2515 bfd_boolean use_ibt_plt;
2516 unsigned int plt_alignment, features, isa_level;
2517 struct elf_x86_link_hash_table *htab;
2518 bfd *pbfd;
2519 bfd *ebfd = NULL;
2520 elf_property *prop;
2521 const struct elf_backend_data *bed;
2522 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2523 unsigned int got_align;
2524
2525 /* Find a normal input file with GNU property note. */
2526 for (pbfd = info->input_bfds;
2527 pbfd != NULL;
2528 pbfd = pbfd->link.next)
2529 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2530 && bfd_count_sections (pbfd) != 0)
2531 {
2532 ebfd = pbfd;
2533
2534 if (elf_properties (pbfd) != NULL)
2535 break;
2536 }
2537
2538 bed = get_elf_backend_data (info->output_bfd);
2539
2540 htab = elf_x86_hash_table (info, bed->target_id);
2541 if (htab == NULL)
2542 return pbfd;
2543
2544 features = 0;
2545 if (htab->params->ibt)
2546 {
2547 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2548 htab->params->cet_report &= ~prop_report_ibt;
2549 }
2550 if (htab->params->shstk)
2551 {
2552 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2553 htab->params->cet_report &= ~prop_report_shstk;
2554 }
2555 if (!(htab->params->cet_report & (prop_report_ibt | prop_report_shstk)))
2556 htab->params->cet_report = prop_report_none;
2557 if (htab->params->lam_u48)
2558 {
2559 features |= GNU_PROPERTY_X86_FEATURE_1_LAM_U48;
2560 htab->params->lam_u48_report = prop_report_none;
2561 }
2562 if (htab->params->lam_u57)
2563 {
2564 features |= GNU_PROPERTY_X86_FEATURE_1_LAM_U57;
2565 htab->params->lam_u57_report = prop_report_none;
2566 }
2567
2568 switch (htab->params->isa_level)
2569 {
2570 case 0:
2571 isa_level = 0;
2572 break;
2573 case 1:
2574 isa_level = GNU_PROPERTY_X86_ISA_1_BASELINE;
2575 break;
2576 case 2:
2577 isa_level = GNU_PROPERTY_X86_ISA_1_V2;
2578 break;
2579 case 3:
2580 isa_level = GNU_PROPERTY_X86_ISA_1_V3;
2581 break;
2582 case 4:
2583 isa_level = GNU_PROPERTY_X86_ISA_1_V4;
2584 break;
2585 default:
2586 abort ();
2587 }
2588
2589 if (ebfd != NULL)
2590 {
2591 prop = NULL;
2592 if (features)
2593 {
2594 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT,
2595 GNU_PROPERTY_X86_FEATURE_1_SHSTK,
2596 GNU_PROPERTY_X86_FEATURE_1_LAM_U48 and
2597 GNU_PROPERTY_X86_FEATURE_1_LAM_U57. */
2598 prop = _bfd_elf_get_property (ebfd,
2599 GNU_PROPERTY_X86_FEATURE_1_AND,
2600 4);
2601 prop->u.number |= features;
2602 prop->pr_kind = property_number;
2603 }
2604
2605 if (isa_level)
2606 {
2607 /* If ISA level is set, add GNU_PROPERTY_X86_ISA_1_NEEDED. */
2608 prop = _bfd_elf_get_property (ebfd,
2609 GNU_PROPERTY_X86_ISA_1_NEEDED,
2610 4);
2611 prop->u.number |= isa_level;
2612 prop->pr_kind = property_number;
2613 }
2614
2615 /* Create the GNU property note section if needed. */
2616 if (prop != NULL && pbfd == NULL)
2617 {
2618 sec = bfd_make_section_with_flags (ebfd,
2619 NOTE_GNU_PROPERTY_SECTION_NAME,
2620 (SEC_ALLOC
2621 | SEC_LOAD
2622 | SEC_IN_MEMORY
2623 | SEC_READONLY
2624 | SEC_HAS_CONTENTS
2625 | SEC_DATA));
2626 if (sec == NULL)
2627 info->callbacks->einfo (_("%F%P: failed to create GNU property section\n"));
2628
2629 if (!bfd_set_section_alignment (sec, class_align))
2630 {
2631 error_alignment:
2632 info->callbacks->einfo (_("%F%pA: failed to align section\n"),
2633 sec);
2634 }
2635
2636 elf_section_type (sec) = SHT_NOTE;
2637 }
2638 }
2639
2640 if (htab->params->cet_report
2641 || htab->params->lam_u48_report
2642 || htab->params->lam_u57_report)
2643 {
2644 /* Report missing IBT, SHSTK and LAM properties. */
2645 bfd *abfd;
2646 const char *warning_msg = _("%P: %pB: warning: missing %s\n");
2647 const char *error_msg = _("%X%P: %pB: error: missing %s\n");
2648 const char *cet_msg = NULL;
2649 const char *lam_u48_msg = NULL;
2650 const char *lam_u57_msg = NULL;
2651 const char *missing;
2652 elf_property_list *p;
2653 bfd_boolean missing_ibt, missing_shstk;
2654 bfd_boolean missing_lam_u48, missing_lam_u57;
2655 bfd_boolean check_ibt
2656 = (htab->params->cet_report
2657 && (htab->params->cet_report & prop_report_ibt));
2658 bfd_boolean check_shstk
2659 = (htab->params->cet_report
2660 && (htab->params->cet_report & prop_report_shstk));
2661
2662 if (htab->params->cet_report)
2663 {
2664 if ((htab->params->cet_report & prop_report_warning))
2665 cet_msg = warning_msg;
2666 else
2667 cet_msg = error_msg;
2668 }
2669 if (htab->params->lam_u48_report)
2670 {
2671 if ((htab->params->lam_u48_report & prop_report_warning))
2672 lam_u48_msg = warning_msg;
2673 else
2674 lam_u48_msg = error_msg;
2675 }
2676 if (htab->params->lam_u57_report)
2677 {
2678 if ((htab->params->lam_u57_report & prop_report_warning))
2679 lam_u57_msg = warning_msg;
2680 else
2681 lam_u57_msg = error_msg;
2682 }
2683
2684 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
2685 if (!(abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED))
2686 && bfd_get_flavour (abfd) == bfd_target_elf_flavour)
2687 {
2688 for (p = elf_properties (abfd); p; p = p->next)
2689 if (p->property.pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2690 break;
2691
2692 missing_ibt = check_ibt;
2693 missing_shstk = check_shstk;
2694 missing_lam_u48 = !!lam_u48_msg;
2695 missing_lam_u57 = !!lam_u57_msg;
2696 if (p)
2697 {
2698 missing_ibt &= !(p->property.u.number
2699 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2700 missing_shstk &= !(p->property.u.number
2701 & GNU_PROPERTY_X86_FEATURE_1_SHSTK);
2702 missing_lam_u48 &= !(p->property.u.number
2703 & GNU_PROPERTY_X86_FEATURE_1_LAM_U48);
2704 missing_lam_u57 &= !(p->property.u.number
2705 & GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
2706 }
2707 if (missing_ibt || missing_shstk)
2708 {
2709 if (missing_ibt && missing_shstk)
2710 missing = _("IBT and SHSTK properties");
2711 else if (missing_ibt)
2712 missing = _("IBT property");
2713 else
2714 missing = _("SHSTK property");
2715 info->callbacks->einfo (cet_msg, abfd, missing);
2716 }
2717 if (missing_lam_u48)
2718 {
2719 missing = _("LAM_U48 property");
2720 info->callbacks->einfo (lam_u48_msg, abfd, missing);
2721 }
2722 if (missing_lam_u57)
2723 {
2724 missing = _("LAM_U57 property");
2725 info->callbacks->einfo (lam_u57_msg, abfd, missing);
2726 }
2727 }
2728 }
2729
2730 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2731
2732 htab->r_info = init_table->r_info;
2733 htab->r_sym = init_table->r_sym;
2734
2735 if (bfd_link_relocatable (info))
2736 return pbfd;
2737
2738 htab->plt0_pad_byte = init_table->plt0_pad_byte;
2739
2740 use_ibt_plt = htab->params->ibtplt || htab->params->ibt;
2741 if (!use_ibt_plt && pbfd != NULL)
2742 {
2743 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2744 elf_property_list *p;
2745
2746 /* The property list is sorted in order of type. */
2747 for (p = elf_properties (pbfd); p; p = p->next)
2748 {
2749 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2750 {
2751 use_ibt_plt = !!(p->property.u.number
2752 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2753 break;
2754 }
2755 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2756 break;
2757 }
2758 }
2759
2760 dynobj = htab->elf.dynobj;
2761
2762 /* Set htab->elf.dynobj here so that there is no need to check and
2763 set it in check_relocs. */
2764 if (dynobj == NULL)
2765 {
2766 if (pbfd != NULL)
2767 {
2768 htab->elf.dynobj = pbfd;
2769 dynobj = pbfd;
2770 }
2771 else
2772 {
2773 bfd *abfd;
2774
2775 /* Find a normal input file to hold linker created
2776 sections. */
2777 for (abfd = info->input_bfds;
2778 abfd != NULL;
2779 abfd = abfd->link.next)
2780 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2781 && (abfd->flags
2782 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
2783 && bed->relocs_compatible (abfd->xvec,
2784 info->output_bfd->xvec))
2785 {
2786 htab->elf.dynobj = abfd;
2787 dynobj = abfd;
2788 break;
2789 }
2790 }
2791 }
2792
2793 /* Return if there are no normal input files. */
2794 if (dynobj == NULL)
2795 return pbfd;
2796
2797 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2798 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2799 canonical function address. */
2800 htab->plt.has_plt0 = 1;
2801 normal_target = htab->elf.target_os == is_normal;
2802
2803 if (normal_target)
2804 {
2805 if (use_ibt_plt)
2806 {
2807 htab->lazy_plt = init_table->lazy_ibt_plt;
2808 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2809 }
2810 else
2811 {
2812 htab->lazy_plt = init_table->lazy_plt;
2813 htab->non_lazy_plt = init_table->non_lazy_plt;
2814 }
2815 }
2816 else
2817 {
2818 htab->lazy_plt = init_table->lazy_plt;
2819 htab->non_lazy_plt = NULL;
2820 }
2821
2822 pltsec = htab->elf.splt;
2823
2824 /* If the non-lazy PLT is available, use it for all PLT entries if
2825 there are no PLT0 or no .plt section. */
2826 if (htab->non_lazy_plt != NULL
2827 && (!htab->plt.has_plt0 || pltsec == NULL))
2828 {
2829 lazy_plt = FALSE;
2830 if (bfd_link_pic (info))
2831 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2832 else
2833 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2834 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2835 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2836 htab->plt.plt_got_insn_size
2837 = htab->non_lazy_plt->plt_got_insn_size;
2838 htab->plt.eh_frame_plt_size
2839 = htab->non_lazy_plt->eh_frame_plt_size;
2840 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2841 }
2842 else
2843 {
2844 lazy_plt = TRUE;
2845 if (bfd_link_pic (info))
2846 {
2847 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2848 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2849 }
2850 else
2851 {
2852 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2853 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2854 }
2855 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2856 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2857 htab->plt.plt_got_insn_size
2858 = htab->lazy_plt->plt_got_insn_size;
2859 htab->plt.eh_frame_plt_size
2860 = htab->lazy_plt->eh_frame_plt_size;
2861 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2862 }
2863
2864 if (htab->elf.target_os == is_vxworks
2865 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2866 &htab->srelplt2))
2867 {
2868 info->callbacks->einfo (_("%F%P: failed to create VxWorks dynamic sections\n"));
2869 return pbfd;
2870 }
2871
2872 /* Since create_dynamic_sections isn't always called, but GOT
2873 relocations need GOT relocations, create them here so that we
2874 don't need to do it in check_relocs. */
2875 if (htab->elf.sgot == NULL
2876 && !_bfd_elf_create_got_section (dynobj, info))
2877 info->callbacks->einfo (_("%F%P: failed to create GOT sections\n"));
2878
2879 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2880
2881 /* Align .got and .got.plt sections to their entry size. Do it here
2882 instead of in create_dynamic_sections so that they are always
2883 properly aligned even if create_dynamic_sections isn't called. */
2884 sec = htab->elf.sgot;
2885 if (!bfd_set_section_alignment (sec, got_align))
2886 goto error_alignment;
2887
2888 sec = htab->elf.sgotplt;
2889 if (!bfd_set_section_alignment (sec, got_align))
2890 goto error_alignment;
2891
2892 /* Create the ifunc sections here so that check_relocs can be
2893 simplified. */
2894 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2895 info->callbacks->einfo (_("%F%P: failed to create ifunc sections\n"));
2896
2897 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2898
2899 if (pltsec != NULL)
2900 {
2901 /* Whe creating executable, set the contents of the .interp
2902 section to the interpreter. */
2903 if (bfd_link_executable (info) && !info->nointerp)
2904 {
2905 asection *s = bfd_get_linker_section (dynobj, ".interp");
2906 if (s == NULL)
2907 abort ();
2908 s->size = htab->dynamic_interpreter_size;
2909 s->contents = (unsigned char *) htab->dynamic_interpreter;
2910 htab->interp = s;
2911 }
2912
2913 if (normal_target)
2914 {
2915 flagword pltflags = (bed->dynamic_sec_flags
2916 | SEC_ALLOC
2917 | SEC_CODE
2918 | SEC_LOAD
2919 | SEC_READONLY);
2920 unsigned int non_lazy_plt_alignment
2921 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2922
2923 sec = pltsec;
2924 if (!bfd_set_section_alignment (sec, plt_alignment))
2925 goto error_alignment;
2926
2927 /* Create the GOT procedure linkage table. */
2928 sec = bfd_make_section_anyway_with_flags (dynobj,
2929 ".plt.got",
2930 pltflags);
2931 if (sec == NULL)
2932 info->callbacks->einfo (_("%F%P: failed to create GOT PLT section\n"));
2933
2934 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
2935 goto error_alignment;
2936
2937 htab->plt_got = sec;
2938
2939 if (lazy_plt)
2940 {
2941 sec = NULL;
2942
2943 if (use_ibt_plt)
2944 {
2945 /* Create the second PLT for Intel IBT support. IBT
2946 PLT is needed only for lazy binding. */
2947 sec = bfd_make_section_anyway_with_flags (dynobj,
2948 ".plt.sec",
2949 pltflags);
2950 if (sec == NULL)
2951 info->callbacks->einfo (_("%F%P: failed to create IBT-enabled PLT section\n"));
2952
2953 if (!bfd_set_section_alignment (sec, plt_alignment))
2954 goto error_alignment;
2955 }
2956 else if (htab->params->bndplt && ABI_64_P (dynobj))
2957 {
2958 /* Create the second PLT for Intel MPX support. MPX
2959 PLT is supported only in 64-bit mode and is needed
2960 only for lazy binding. */
2961 sec = bfd_make_section_anyway_with_flags (dynobj,
2962 ".plt.sec",
2963 pltflags);
2964 if (sec == NULL)
2965 info->callbacks->einfo (_("%F%P: failed to create BND PLT section\n"));
2966
2967 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
2968 goto error_alignment;
2969 }
2970
2971 htab->plt_second = sec;
2972 }
2973 }
2974
2975 if (!info->no_ld_generated_unwind_info)
2976 {
2977 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
2978 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
2979 | SEC_LINKER_CREATED);
2980
2981 sec = bfd_make_section_anyway_with_flags (dynobj,
2982 ".eh_frame",
2983 flags);
2984 if (sec == NULL)
2985 info->callbacks->einfo (_("%F%P: failed to create PLT .eh_frame section\n"));
2986
2987 if (!bfd_set_section_alignment (sec, class_align))
2988 goto error_alignment;
2989
2990 htab->plt_eh_frame = sec;
2991
2992 if (htab->plt_got != NULL)
2993 {
2994 sec = bfd_make_section_anyway_with_flags (dynobj,
2995 ".eh_frame",
2996 flags);
2997 if (sec == NULL)
2998 info->callbacks->einfo (_("%F%P: failed to create GOT PLT .eh_frame section\n"));
2999
3000 if (!bfd_set_section_alignment (sec, class_align))
3001 goto error_alignment;
3002
3003 htab->plt_got_eh_frame = sec;
3004 }
3005
3006 if (htab->plt_second != NULL)
3007 {
3008 sec = bfd_make_section_anyway_with_flags (dynobj,
3009 ".eh_frame",
3010 flags);
3011 if (sec == NULL)
3012 info->callbacks->einfo (_("%F%P: failed to create the second PLT .eh_frame section\n"));
3013
3014 if (!bfd_set_section_alignment (sec, class_align))
3015 goto error_alignment;
3016
3017 htab->plt_second_eh_frame = sec;
3018 }
3019 }
3020 }
3021
3022 /* The .iplt section is used for IFUNC symbols in static
3023 executables. */
3024 sec = htab->elf.iplt;
3025 if (sec != NULL)
3026 {
3027 /* NB: Delay setting its alignment until we know it is non-empty.
3028 Otherwise an empty iplt section may change vma and lma of the
3029 following sections, which triggers moving dot of the following
3030 section backwards, resulting in a warning and section lma not
3031 being set properly. It later leads to a "File truncated"
3032 error. */
3033 if (!bfd_set_section_alignment (sec, 0))
3034 goto error_alignment;
3035
3036 htab->plt.iplt_alignment = (normal_target
3037 ? plt_alignment
3038 : bed->plt_alignment);
3039 }
3040
3041 if (bfd_link_executable (info)
3042 && !info->nointerp
3043 && !htab->params->has_dynamic_linker
3044 && htab->params->static_before_all_inputs)
3045 {
3046 /* Report error for dynamic input objects if -static is passed at
3047 command-line before all input files without --dynamic-linker
3048 unless --no-dynamic-linker is used. */
3049 bfd *abfd;
3050
3051 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
3052 if ((abfd->flags & DYNAMIC))
3053 info->callbacks->einfo
3054 (_("%X%P: attempted static link of dynamic object `%pB'\n"),
3055 abfd);
3056 }
3057
3058 return pbfd;
3059 }
3060
3061 /* Fix up x86 GNU properties. */
3062
3063 void
3064 _bfd_x86_elf_link_fixup_gnu_properties
3065 (struct bfd_link_info *info, elf_property_list **listp)
3066 {
3067 elf_property_list *p;
3068
3069 for (p = *listp; p; p = p->next)
3070 {
3071 unsigned int type = p->property.pr_type;
3072 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
3073 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3074 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3075 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3076 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3077 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
3078 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
3079 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
3080 {
3081 if (p->property.u.number == 0
3082 && (type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3083 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3084 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3085 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3086 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)))
3087 {
3088 /* Remove empty property. */
3089 *listp = p->next;
3090 continue;
3091 }
3092
3093 /* Keep LAM features only for 64-bit output. */
3094 if (type == GNU_PROPERTY_X86_FEATURE_1_AND
3095 && !ABI_64_P (info->output_bfd))
3096 p->property.u.number &= ~(GNU_PROPERTY_X86_FEATURE_1_LAM_U48
3097 | GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
3098
3099 listp = &p->next;
3100 }
3101 else if (type > GNU_PROPERTY_HIPROC)
3102 {
3103 /* The property list is sorted in order of type. */
3104 break;
3105 }
3106 }
3107 }
3108
3109 void
3110 _bfd_elf_linker_x86_set_options (struct bfd_link_info * info,
3111 struct elf_linker_x86_params *params)
3112 {
3113 const struct elf_backend_data *bed
3114 = get_elf_backend_data (info->output_bfd);
3115 struct elf_x86_link_hash_table *htab
3116 = elf_x86_hash_table (info, bed->target_id);
3117 if (htab != NULL)
3118 htab->params = params;
3119 }