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x86: Propery check PC16 reloc overflow in 16-bit mode instructions
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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 bool
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 bool
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 bool 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 bool 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 bool 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 bool 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 int
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 bool 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 bool
687 elf_i386_is_reloc_section (const char *secname)
688 {
689 return startswith (secname, ".rel");
690 }
691
692 static bool
693 elf_x86_64_is_reloc_section (const char *secname)
694 {
695 return startswith (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 bool
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 bool
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 bool *no_dynreloc_p)
902 {
903 bool 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 bool
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 bool 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 bool 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 bool
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 bool definition,
1629 bool 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 bool
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 {
1716 asection *plt_s;
1717 bfd_vma plt_offset;
1718 bfd *output_bfd = info->output_bfd;
1719
1720 if (htab->plt_second)
1721 {
1722 struct elf_x86_link_hash_entry *eh
1723 = (struct elf_x86_link_hash_entry *) h;
1724
1725 plt_s = htab->plt_second;
1726 plt_offset = eh->plt_second.offset;
1727 }
1728 else
1729 {
1730 plt_s = htab->elf.splt;
1731 plt_offset = h->plt.offset;
1732 }
1733
1734 sym->st_size = 0;
1735 sym->st_info = ELF_ST_INFO (ELF_ST_BIND (sym->st_info), STT_FUNC);
1736 sym->st_shndx
1737 = _bfd_elf_section_from_bfd_section (output_bfd,
1738 plt_s->output_section);
1739 sym->st_value = (plt_s->output_section->vma
1740 + plt_s->output_offset + plt_offset);
1741 }
1742 }
1743
1744 /* Report relative relocation. */
1745
1746 void
1747 _bfd_x86_elf_link_report_relative_reloc
1748 (struct bfd_link_info *info, asection *asect,
1749 struct elf_link_hash_entry *h, Elf_Internal_Sym *sym,
1750 const char *reloc_name, const void *reloc)
1751 {
1752 const char *name;
1753 bfd *abfd;
1754 const Elf_Internal_Rela *rel = (const Elf_Internal_Rela *) reloc;
1755 char r_offset[30], r_info[30];
1756
1757 /* Use the output BFD for linker created sections. */
1758 if ((asect->flags & SEC_LINKER_CREATED) != 0)
1759 abfd = info->output_bfd;
1760 else
1761 abfd = asect->owner;
1762
1763 if (h != NULL && h->root.root.string != NULL)
1764 name = h->root.root.string;
1765 else
1766 name = bfd_elf_sym_name (abfd, &elf_symtab_hdr (abfd), sym, NULL);
1767
1768 bfd_sprintf_vma (abfd, r_offset, rel->r_offset);
1769 bfd_sprintf_vma (abfd, r_info, rel->r_info);
1770
1771 if (asect->use_rela_p)
1772 {
1773 char r_addend[30];
1774
1775 bfd_sprintf_vma (abfd, r_addend, rel->r_addend);
1776
1777 info->callbacks->einfo
1778 (_("%pB: %s (offset: 0x%s, info: 0x%s, addend: 0x%s) against "
1779 "'%s' " "for section '%pA' in %pB\n"),
1780 info->output_bfd, reloc_name, r_offset, r_info, r_addend,
1781 name, asect, abfd);
1782 }
1783 else
1784 info->callbacks->einfo
1785 (_("%pB: %s (offset: 0x%s, info: 0x%s) against '%s' for section "
1786 "'%pA' in %pB\n"),
1787 info->output_bfd, reloc_name, r_offset, r_info, name,
1788 asect, abfd);
1789 }
1790
1791 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1792
1793 bool
1794 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1795 {
1796 if (h->plt.offset != (bfd_vma) -1
1797 && !h->def_regular
1798 && !h->pointer_equality_needed)
1799 return false;
1800
1801 return _bfd_elf_hash_symbol (h);
1802 }
1803
1804 /* Adjust a symbol defined by a dynamic object and referenced by a
1805 regular object. The current definition is in some section of the
1806 dynamic object, but we're not including those sections. We have to
1807 change the definition to something the rest of the link can
1808 understand. */
1809
1810 bool
1811 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1812 struct elf_link_hash_entry *h)
1813 {
1814 struct elf_x86_link_hash_table *htab;
1815 asection *s, *srel;
1816 struct elf_x86_link_hash_entry *eh;
1817 struct elf_dyn_relocs *p;
1818 const struct elf_backend_data *bed
1819 = get_elf_backend_data (info->output_bfd);
1820
1821 /* STT_GNU_IFUNC symbol must go through PLT. */
1822 if (h->type == STT_GNU_IFUNC)
1823 {
1824 /* All local STT_GNU_IFUNC references must be treate as local
1825 calls via local PLT. */
1826 if (h->ref_regular
1827 && SYMBOL_CALLS_LOCAL (info, h))
1828 {
1829 bfd_size_type pc_count = 0, count = 0;
1830 struct elf_dyn_relocs **pp;
1831
1832 eh = (struct elf_x86_link_hash_entry *) h;
1833 for (pp = &h->dyn_relocs; (p = *pp) != NULL; )
1834 {
1835 pc_count += p->pc_count;
1836 p->count -= p->pc_count;
1837 p->pc_count = 0;
1838 count += p->count;
1839 if (p->count == 0)
1840 *pp = p->next;
1841 else
1842 pp = &p->next;
1843 }
1844
1845 if (pc_count || count)
1846 {
1847 h->non_got_ref = 1;
1848 if (pc_count)
1849 {
1850 /* Increment PLT reference count only for PC-relative
1851 references. */
1852 h->needs_plt = 1;
1853 if (h->plt.refcount <= 0)
1854 h->plt.refcount = 1;
1855 else
1856 h->plt.refcount += 1;
1857 }
1858 }
1859 }
1860
1861 if (h->plt.refcount <= 0)
1862 {
1863 h->plt.offset = (bfd_vma) -1;
1864 h->needs_plt = 0;
1865 }
1866 return true;
1867 }
1868
1869 /* If this is a function, put it in the procedure linkage table. We
1870 will fill in the contents of the procedure linkage table later,
1871 when we know the address of the .got section. */
1872 if (h->type == STT_FUNC
1873 || h->needs_plt)
1874 {
1875 if (h->plt.refcount <= 0
1876 || SYMBOL_CALLS_LOCAL (info, h)
1877 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1878 && h->root.type == bfd_link_hash_undefweak))
1879 {
1880 /* This case can occur if we saw a PLT32 reloc in an input
1881 file, but the symbol was never referred to by a dynamic
1882 object, or if all references were garbage collected. In
1883 such a case, we don't actually need to build a procedure
1884 linkage table, and we can just do a PC32 reloc instead. */
1885 h->plt.offset = (bfd_vma) -1;
1886 h->needs_plt = 0;
1887 }
1888
1889 return true;
1890 }
1891 else
1892 /* It's possible that we incorrectly decided a .plt reloc was needed
1893 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
1894 check_relocs. We can't decide accurately between function and
1895 non-function syms in check-relocs; Objects loaded later in
1896 the link may change h->type. So fix it now. */
1897 h->plt.offset = (bfd_vma) -1;
1898
1899 eh = (struct elf_x86_link_hash_entry *) h;
1900
1901 /* If this is a weak symbol, and there is a real definition, the
1902 processor independent code will have arranged for us to see the
1903 real definition first, and we can just use the same value. */
1904 if (h->is_weakalias)
1905 {
1906 struct elf_link_hash_entry *def = weakdef (h);
1907 BFD_ASSERT (def->root.type == bfd_link_hash_defined);
1908 h->root.u.def.section = def->root.u.def.section;
1909 h->root.u.def.value = def->root.u.def.value;
1910 if (ELIMINATE_COPY_RELOCS
1911 || info->nocopyreloc
1912 || SYMBOL_NO_COPYRELOC (info, eh))
1913 {
1914 /* NB: needs_copy is always 0 for i386. */
1915 h->non_got_ref = def->non_got_ref;
1916 eh->needs_copy = def->needs_copy;
1917 }
1918 return true;
1919 }
1920
1921 /* This is a reference to a symbol defined by a dynamic object which
1922 is not a function. */
1923
1924 /* If we are creating a shared library, we must presume that the
1925 only references to the symbol are via the global offset table.
1926 For such cases we need not do anything here; the relocations will
1927 be handled correctly by relocate_section. */
1928 if (!bfd_link_executable (info))
1929 return true;
1930
1931 /* If there are no references to this symbol that do not use the
1932 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
1933 reloc. NB: gotoff_ref is always 0 for x86-64. */
1934 if (!h->non_got_ref && !eh->gotoff_ref)
1935 return true;
1936
1937 /* If -z nocopyreloc was given, we won't generate them either. */
1938 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
1939 {
1940 h->non_got_ref = 0;
1941 return true;
1942 }
1943
1944 htab = elf_x86_hash_table (info, bed->target_id);
1945 if (htab == NULL)
1946 return false;
1947
1948 /* If there aren't any dynamic relocs in read-only sections nor
1949 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
1950 avoid the copy reloc. This doesn't work on VxWorks, where we can
1951 not have dynamic relocations (other than copy and jump slot
1952 relocations) in an executable. */
1953 if (ELIMINATE_COPY_RELOCS
1954 && (bed->target_id == X86_64_ELF_DATA
1955 || (!eh->gotoff_ref
1956 && htab->elf.target_os != is_vxworks)))
1957 {
1958 /* If we don't find any dynamic relocs in read-only sections,
1959 then we'll be keeping the dynamic relocs and avoiding the copy
1960 reloc. */
1961 if (!_bfd_elf_readonly_dynrelocs (h))
1962 {
1963 h->non_got_ref = 0;
1964 return true;
1965 }
1966 }
1967
1968 /* We must allocate the symbol in our .dynbss section, which will
1969 become part of the .bss section of the executable. There will be
1970 an entry for this symbol in the .dynsym section. The dynamic
1971 object will contain position independent code, so all references
1972 from the dynamic object to this symbol will go through the global
1973 offset table. The dynamic linker will use the .dynsym entry to
1974 determine the address it must put in the global offset table, so
1975 both the dynamic object and the regular object will refer to the
1976 same memory location for the variable. */
1977
1978 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
1979 dynamic linker to copy the initial value out of the dynamic object
1980 and into the runtime process image. */
1981 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
1982 {
1983 s = htab->elf.sdynrelro;
1984 srel = htab->elf.sreldynrelro;
1985 }
1986 else
1987 {
1988 s = htab->elf.sdynbss;
1989 srel = htab->elf.srelbss;
1990 }
1991 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
1992 {
1993 srel->size += htab->sizeof_reloc;
1994 h->needs_copy = 1;
1995 }
1996
1997 return _bfd_elf_adjust_dynamic_copy (info, h, s);
1998 }
1999
2000 void
2001 _bfd_x86_elf_hide_symbol (struct bfd_link_info *info,
2002 struct elf_link_hash_entry *h,
2003 bool force_local)
2004 {
2005 if (h->root.type == bfd_link_hash_undefweak
2006 && info->nointerp
2007 && bfd_link_pie (info))
2008 {
2009 /* When there is no dynamic interpreter in PIE, make the undefined
2010 weak symbol dynamic so that PC relative branch to the undefined
2011 weak symbol will land to address 0. */
2012 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
2013 if (h->plt.refcount > 0
2014 || eh->plt_got.refcount > 0)
2015 return;
2016 }
2017
2018 _bfd_elf_link_hash_hide_symbol (info, h, force_local);
2019 }
2020
2021 /* Return TRUE if a symbol is referenced locally. It is similar to
2022 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
2023 works in check_relocs. */
2024
2025 bool
2026 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
2027 struct elf_link_hash_entry *h)
2028 {
2029 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
2030 struct elf_x86_link_hash_table *htab
2031 = (struct elf_x86_link_hash_table *) info->hash;
2032
2033 if (eh->local_ref > 1)
2034 return true;
2035
2036 if (eh->local_ref == 1)
2037 return false;
2038
2039 /* Unversioned symbols defined in regular objects can be forced local
2040 by linker version script. A weak undefined symbol is forced local
2041 if
2042 1. It has non-default visibility. Or
2043 2. When building executable, there is no dynamic linker. Or
2044 3. or "-z nodynamic-undefined-weak" is used.
2045 */
2046 if (SYMBOL_REFERENCES_LOCAL (info, h)
2047 || (h->root.type == bfd_link_hash_undefweak
2048 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
2049 || (bfd_link_executable (info)
2050 && htab->interp == NULL)
2051 || info->dynamic_undefined_weak == 0))
2052 || ((h->def_regular || ELF_COMMON_DEF_P (h))
2053 && info->version_info != NULL
2054 && _bfd_elf_link_hide_sym_by_version (info, h)))
2055 {
2056 eh->local_ref = 2;
2057 return true;
2058 }
2059
2060 eh->local_ref = 1;
2061 return false;
2062 }
2063
2064 /* Return the section that should be marked against GC for a given
2065 relocation. */
2066
2067 asection *
2068 _bfd_x86_elf_gc_mark_hook (asection *sec,
2069 struct bfd_link_info *info,
2070 Elf_Internal_Rela *rel,
2071 struct elf_link_hash_entry *h,
2072 Elf_Internal_Sym *sym)
2073 {
2074 /* Compiler should optimize this out. */
2075 if (((unsigned int) R_X86_64_GNU_VTINHERIT
2076 != (unsigned int) R_386_GNU_VTINHERIT)
2077 || ((unsigned int) R_X86_64_GNU_VTENTRY
2078 != (unsigned int) R_386_GNU_VTENTRY))
2079 abort ();
2080
2081 if (h != NULL)
2082 switch (ELF32_R_TYPE (rel->r_info))
2083 {
2084 case R_X86_64_GNU_VTINHERIT:
2085 case R_X86_64_GNU_VTENTRY:
2086 return NULL;
2087 }
2088
2089 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
2090 }
2091
2092 static bfd_vma
2093 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
2094 bfd_vma off,
2095 bfd_vma offset ATTRIBUTE_UNUSED,
2096 bfd_vma got_addr)
2097 {
2098 return got_addr + off;
2099 }
2100
2101 static bfd_vma
2102 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
2103 bfd_vma off,
2104 bfd_vma offset,
2105 bfd_vma got_addr ATTRIBUTE_UNUSED)
2106 {
2107 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
2108 }
2109
2110 static bool
2111 elf_i386_valid_plt_reloc_p (unsigned int type)
2112 {
2113 return (type == R_386_JUMP_SLOT
2114 || type == R_386_GLOB_DAT
2115 || type == R_386_IRELATIVE);
2116 }
2117
2118 static bool
2119 elf_x86_64_valid_plt_reloc_p (unsigned int type)
2120 {
2121 return (type == R_X86_64_JUMP_SLOT
2122 || type == R_X86_64_GLOB_DAT
2123 || type == R_X86_64_IRELATIVE);
2124 }
2125
2126 long
2127 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
2128 long count,
2129 long relsize,
2130 bfd_vma got_addr,
2131 struct elf_x86_plt plts[],
2132 asymbol **dynsyms,
2133 asymbol **ret)
2134 {
2135 long size, i, n, len;
2136 int j;
2137 unsigned int plt_got_offset, plt_entry_size;
2138 asymbol *s;
2139 bfd_byte *plt_contents;
2140 long dynrelcount;
2141 arelent **dynrelbuf, *p;
2142 char *names;
2143 const struct elf_backend_data *bed;
2144 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
2145 bfd_vma);
2146 bool (*valid_plt_reloc_p) (unsigned int);
2147
2148 dynrelbuf = NULL;
2149 if (count == 0)
2150 goto bad_return;
2151
2152 dynrelbuf = (arelent **) bfd_malloc (relsize);
2153 if (dynrelbuf == NULL)
2154 goto bad_return;
2155
2156 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
2157 dynsyms);
2158 if (dynrelcount <= 0)
2159 goto bad_return;
2160
2161 /* Sort the relocs by address. */
2162 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
2163 _bfd_x86_elf_compare_relocs);
2164
2165 size = count * sizeof (asymbol);
2166
2167 /* Allocate space for @plt suffixes. */
2168 n = 0;
2169 for (i = 0; i < dynrelcount; i++)
2170 {
2171 p = dynrelbuf[i];
2172 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
2173 if (p->addend != 0)
2174 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
2175 }
2176
2177 s = *ret = (asymbol *) bfd_zmalloc (size);
2178 if (s == NULL)
2179 goto bad_return;
2180
2181 bed = get_elf_backend_data (abfd);
2182
2183 if (bed->target_id == X86_64_ELF_DATA)
2184 {
2185 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
2186 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
2187 }
2188 else
2189 {
2190 get_plt_got_vma = elf_i386_get_plt_got_vma;
2191 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
2192 if (got_addr)
2193 {
2194 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
2195 address. */
2196 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
2197 if (sec != NULL)
2198 got_addr = sec->vma;
2199 else
2200 {
2201 sec = bfd_get_section_by_name (abfd, ".got");
2202 if (sec != NULL)
2203 got_addr = sec->vma;
2204 }
2205
2206 if (got_addr == (bfd_vma) -1)
2207 goto bad_return;
2208 }
2209 }
2210
2211 /* Check for each PLT section. */
2212 names = (char *) (s + count);
2213 size = 0;
2214 n = 0;
2215 for (j = 0; plts[j].name != NULL; j++)
2216 if ((plt_contents = plts[j].contents) != NULL)
2217 {
2218 long k;
2219 bfd_vma offset;
2220 asection *plt;
2221 struct elf_x86_plt *plt_p = &plts[j];
2222
2223 plt_got_offset = plt_p->plt_got_offset;
2224 plt_entry_size = plt_p->plt_entry_size;
2225
2226 plt = plt_p->sec;
2227
2228 if ((plt_p->type & plt_lazy))
2229 {
2230 /* Skip PLT0 in lazy PLT. */
2231 k = 1;
2232 offset = plt_entry_size;
2233 }
2234 else
2235 {
2236 k = 0;
2237 offset = 0;
2238 }
2239
2240 /* Check each PLT entry against dynamic relocations. */
2241 for (; k < plt_p->count; k++)
2242 {
2243 int off;
2244 bfd_vma got_vma;
2245 long min, max, mid;
2246
2247 /* Get the GOT offset for i386 or the PC-relative offset
2248 for x86-64, a signed 32-bit integer. */
2249 off = H_GET_32 (abfd, (plt_contents + offset
2250 + plt_got_offset));
2251 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
2252
2253 /* Binary search. */
2254 p = dynrelbuf[0];
2255 min = 0;
2256 max = dynrelcount;
2257 while ((min + 1) < max)
2258 {
2259 arelent *r;
2260
2261 mid = (min + max) / 2;
2262 r = dynrelbuf[mid];
2263 if (got_vma > r->address)
2264 min = mid;
2265 else if (got_vma < r->address)
2266 max = mid;
2267 else
2268 {
2269 p = r;
2270 break;
2271 }
2272 }
2273
2274 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
2275 if (got_vma == p->address
2276 && p->howto != NULL
2277 && valid_plt_reloc_p (p->howto->type))
2278 {
2279 *s = **p->sym_ptr_ptr;
2280 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
2281 set. Since we are defining a symbol, ensure one
2282 of them is set. */
2283 if ((s->flags & BSF_LOCAL) == 0)
2284 s->flags |= BSF_GLOBAL;
2285 s->flags |= BSF_SYNTHETIC;
2286 /* This is no longer a section symbol. */
2287 s->flags &= ~BSF_SECTION_SYM;
2288 s->section = plt;
2289 s->the_bfd = plt->owner;
2290 s->value = offset;
2291 s->udata.p = NULL;
2292 s->name = names;
2293 len = strlen ((*p->sym_ptr_ptr)->name);
2294 memcpy (names, (*p->sym_ptr_ptr)->name, len);
2295 names += len;
2296 if (p->addend != 0)
2297 {
2298 char buf[30], *a;
2299
2300 memcpy (names, "+0x", sizeof ("+0x") - 1);
2301 names += sizeof ("+0x") - 1;
2302 bfd_sprintf_vma (abfd, buf, p->addend);
2303 for (a = buf; *a == '0'; ++a)
2304 ;
2305 size = strlen (a);
2306 memcpy (names, a, size);
2307 names += size;
2308 }
2309 memcpy (names, "@plt", sizeof ("@plt"));
2310 names += sizeof ("@plt");
2311 n++;
2312 s++;
2313 /* There should be only one entry in PLT for a given
2314 symbol. Set howto to NULL after processing a PLT
2315 entry to guard against corrupted PLT. */
2316 p->howto = NULL;
2317 }
2318 offset += plt_entry_size;
2319 }
2320 }
2321
2322 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
2323 if (n == 0)
2324 {
2325 bad_return:
2326 count = -1;
2327 }
2328 else
2329 count = n;
2330
2331 for (j = 0; plts[j].name != NULL; j++)
2332 free (plts[j].contents);
2333
2334 free (dynrelbuf);
2335
2336 return count;
2337 }
2338
2339 /* Parse x86 GNU properties. */
2340
2341 enum elf_property_kind
2342 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
2343 bfd_byte *ptr, unsigned int datasz)
2344 {
2345 elf_property *prop;
2346
2347 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2348 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2349 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
2350 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2351 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
2352 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
2353 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2354 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2355 {
2356 unsigned int number;
2357 if (datasz != 4)
2358 {
2359 _bfd_error_handler
2360 (_("error: %pB: <corrupt x86 property (0x%x) size: 0x%x>"),
2361 abfd, type, datasz);
2362 return property_corrupt;
2363 }
2364 prop = _bfd_elf_get_property (abfd, type, datasz);
2365 number = bfd_h_get_32 (abfd, ptr);
2366 if ((abfd->flags
2367 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
2368 && type == GNU_PROPERTY_X86_FEATURE_2_USED
2369 && (number & GNU_PROPERTY_X86_FEATURE_2_CODE16) != 0)
2370 elf_x86_has_code16 (abfd) = 1;
2371 prop->u.number |= number;
2372 prop->pr_kind = property_number;
2373 return property_number;
2374 }
2375
2376 return property_ignored;
2377 }
2378
2379 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2380 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2381 should be merged with ABFD. */
2382
2383 bool
2384 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2385 bfd *abfd ATTRIBUTE_UNUSED,
2386 bfd *bbfd ATTRIBUTE_UNUSED,
2387 elf_property *aprop,
2388 elf_property *bprop)
2389 {
2390 unsigned int number, features;
2391 bool updated = false;
2392 const struct elf_backend_data *bed;
2393 struct elf_x86_link_hash_table *htab;
2394 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2395
2396 if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
2397 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
2398 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
2399 {
2400 if (aprop == NULL || bprop == NULL)
2401 {
2402 /* Only one of APROP and BPROP can be NULL. */
2403 if (aprop != NULL)
2404 {
2405 /* Remove this property since the other input file doesn't
2406 have it. */
2407 aprop->pr_kind = property_remove;
2408 updated = true;
2409 }
2410 }
2411 else
2412 {
2413 number = aprop->u.number;
2414 aprop->u.number = number | bprop->u.number;
2415 updated = number != (unsigned int) aprop->u.number;
2416 }
2417 return updated;
2418 }
2419 else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
2420 || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_LO
2421 && pr_type <= GNU_PROPERTY_X86_UINT32_OR_HI))
2422 {
2423 features = 0;
2424 if (pr_type == GNU_PROPERTY_X86_ISA_1_NEEDED)
2425 {
2426 bed = get_elf_backend_data (info->output_bfd);
2427 htab = elf_x86_hash_table (info, bed->target_id);
2428 switch (htab->params->isa_level)
2429 {
2430 case 0:
2431 break;
2432 case 2:
2433 features = GNU_PROPERTY_X86_ISA_1_V2;
2434 break;
2435 case 3:
2436 features = GNU_PROPERTY_X86_ISA_1_V3;
2437 break;
2438 case 4:
2439 features = GNU_PROPERTY_X86_ISA_1_V4;
2440 break;
2441 default:
2442 abort ();
2443 }
2444 }
2445 if (aprop != NULL && bprop != NULL)
2446 {
2447 number = aprop->u.number;
2448 aprop->u.number = number | bprop->u.number | features;
2449 /* Remove the property if all bits are empty. */
2450 if (aprop->u.number == 0)
2451 {
2452 aprop->pr_kind = property_remove;
2453 updated = true;
2454 }
2455 else
2456 updated = number != (unsigned int) aprop->u.number;
2457 }
2458 else
2459 {
2460 /* Only one of APROP and BPROP can be NULL. */
2461 if (aprop != NULL)
2462 {
2463 aprop->u.number |= features;
2464 if (aprop->u.number == 0)
2465 {
2466 /* Remove APROP if all bits are empty. */
2467 aprop->pr_kind = property_remove;
2468 updated = true;
2469 }
2470 }
2471 else
2472 {
2473 /* Return TRUE if APROP is NULL and all bits of BPROP
2474 aren't empty to indicate that BPROP should be added
2475 to ABFD. */
2476 bprop->u.number |= features;
2477 updated = bprop->u.number != 0;
2478 }
2479 }
2480 return updated;
2481 }
2482 else if (pr_type >= GNU_PROPERTY_X86_UINT32_AND_LO
2483 && pr_type <= GNU_PROPERTY_X86_UINT32_AND_HI)
2484 {
2485 /* Only one of APROP and BPROP can be NULL:
2486 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2487 2. If APROP is NULL, remove x86 feature.
2488 3. Otherwise, do nothing.
2489 */
2490 bed = get_elf_backend_data (info->output_bfd);
2491 htab = elf_x86_hash_table (info, bed->target_id);
2492 if (!htab)
2493 abort ();
2494 if (aprop != NULL && bprop != NULL)
2495 {
2496 number = aprop->u.number;
2497 aprop->u.number = number & bprop->u.number;
2498 if (pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2499 {
2500 features = 0;
2501 if (htab->params->ibt)
2502 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2503 if (htab->params->shstk)
2504 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2505 if (htab->params->lam_u48)
2506 features |= (GNU_PROPERTY_X86_FEATURE_1_LAM_U48
2507 | GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
2508 else if (htab->params->lam_u57)
2509 features |= GNU_PROPERTY_X86_FEATURE_1_LAM_U57;
2510 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT,
2511 GNU_PROPERTY_X86_FEATURE_1_SHSTK,
2512 GNU_PROPERTY_X86_FEATURE_1_LAM_U48 and
2513 GNU_PROPERTY_X86_FEATURE_1_LAM_U57. */
2514 aprop->u.number |= features;
2515 }
2516 updated = number != (unsigned int) aprop->u.number;
2517 /* Remove the property if all feature bits are cleared. */
2518 if (aprop->u.number == 0)
2519 aprop->pr_kind = property_remove;
2520 }
2521 else
2522 {
2523 /* There should be no AND properties since some input doesn't
2524 have them. Set IBT and SHSTK properties for -z ibt and -z
2525 shstk if needed. */
2526 features = 0;
2527 if (pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2528 {
2529 if (htab->params->ibt)
2530 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2531 if (htab->params->shstk)
2532 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2533 if (htab->params->lam_u48)
2534 features |= (GNU_PROPERTY_X86_FEATURE_1_LAM_U48
2535 | GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
2536 else if (htab->params->lam_u57)
2537 features |= GNU_PROPERTY_X86_FEATURE_1_LAM_U57;
2538 }
2539 if (features)
2540 {
2541 if (aprop != NULL)
2542 {
2543 updated = features != (unsigned int) aprop->u.number;
2544 aprop->u.number = features;
2545 }
2546 else
2547 {
2548 updated = true;
2549 bprop->u.number = features;
2550 }
2551 }
2552 else if (aprop != NULL)
2553 {
2554 aprop->pr_kind = property_remove;
2555 updated = true;
2556 }
2557 }
2558 return updated;
2559 }
2560 else
2561 {
2562 /* Never should happen. */
2563 abort ();
2564 }
2565
2566 return updated;
2567 }
2568
2569 /* Set up x86 GNU properties. Return the first relocatable ELF input
2570 with GNU properties if found. Otherwise, return NULL. */
2571
2572 bfd *
2573 _bfd_x86_elf_link_setup_gnu_properties
2574 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2575 {
2576 bool normal_target;
2577 bool lazy_plt;
2578 asection *sec, *pltsec;
2579 bfd *dynobj;
2580 bool use_ibt_plt;
2581 unsigned int plt_alignment, features, isa_level;
2582 struct elf_x86_link_hash_table *htab;
2583 bfd *pbfd;
2584 bfd *ebfd = NULL;
2585 elf_property *prop;
2586 const struct elf_backend_data *bed;
2587 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2588 unsigned int got_align;
2589
2590 /* Find a normal input file with GNU property note. */
2591 for (pbfd = info->input_bfds;
2592 pbfd != NULL;
2593 pbfd = pbfd->link.next)
2594 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2595 && bfd_count_sections (pbfd) != 0)
2596 {
2597 ebfd = pbfd;
2598
2599 if (elf_properties (pbfd) != NULL)
2600 break;
2601 }
2602
2603 bed = get_elf_backend_data (info->output_bfd);
2604
2605 htab = elf_x86_hash_table (info, bed->target_id);
2606 if (htab == NULL)
2607 return pbfd;
2608
2609 features = 0;
2610 if (htab->params->ibt)
2611 {
2612 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2613 htab->params->cet_report &= ~prop_report_ibt;
2614 }
2615 if (htab->params->shstk)
2616 {
2617 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2618 htab->params->cet_report &= ~prop_report_shstk;
2619 }
2620 if (!(htab->params->cet_report & (prop_report_ibt | prop_report_shstk)))
2621 htab->params->cet_report = prop_report_none;
2622 if (htab->params->lam_u48)
2623 {
2624 features |= (GNU_PROPERTY_X86_FEATURE_1_LAM_U48
2625 | GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
2626 htab->params->lam_u48_report = prop_report_none;
2627 htab->params->lam_u57_report = prop_report_none;
2628 }
2629 else if (htab->params->lam_u57)
2630 {
2631 features |= GNU_PROPERTY_X86_FEATURE_1_LAM_U57;
2632 htab->params->lam_u57_report = prop_report_none;
2633 }
2634
2635 switch (htab->params->isa_level)
2636 {
2637 case 0:
2638 isa_level = 0;
2639 break;
2640 case 1:
2641 isa_level = GNU_PROPERTY_X86_ISA_1_BASELINE;
2642 break;
2643 case 2:
2644 isa_level = GNU_PROPERTY_X86_ISA_1_V2;
2645 break;
2646 case 3:
2647 isa_level = GNU_PROPERTY_X86_ISA_1_V3;
2648 break;
2649 case 4:
2650 isa_level = GNU_PROPERTY_X86_ISA_1_V4;
2651 break;
2652 default:
2653 abort ();
2654 }
2655
2656 if (ebfd != NULL)
2657 {
2658 prop = NULL;
2659 if (features)
2660 {
2661 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT,
2662 GNU_PROPERTY_X86_FEATURE_1_SHSTK,
2663 GNU_PROPERTY_X86_FEATURE_1_LAM_U48 and
2664 GNU_PROPERTY_X86_FEATURE_1_LAM_U57. */
2665 prop = _bfd_elf_get_property (ebfd,
2666 GNU_PROPERTY_X86_FEATURE_1_AND,
2667 4);
2668 prop->u.number |= features;
2669 prop->pr_kind = property_number;
2670 }
2671
2672 if (isa_level)
2673 {
2674 /* If ISA level is set, add GNU_PROPERTY_X86_ISA_1_NEEDED. */
2675 prop = _bfd_elf_get_property (ebfd,
2676 GNU_PROPERTY_X86_ISA_1_NEEDED,
2677 4);
2678 prop->u.number |= isa_level;
2679 prop->pr_kind = property_number;
2680 }
2681
2682 /* Create the GNU property note section if needed. */
2683 if (prop != NULL && pbfd == NULL)
2684 {
2685 sec = bfd_make_section_with_flags (ebfd,
2686 NOTE_GNU_PROPERTY_SECTION_NAME,
2687 (SEC_ALLOC
2688 | SEC_LOAD
2689 | SEC_IN_MEMORY
2690 | SEC_READONLY
2691 | SEC_HAS_CONTENTS
2692 | SEC_DATA));
2693 if (sec == NULL)
2694 info->callbacks->einfo (_("%F%P: failed to create GNU property section\n"));
2695
2696 if (!bfd_set_section_alignment (sec, class_align))
2697 {
2698 error_alignment:
2699 info->callbacks->einfo (_("%F%pA: failed to align section\n"),
2700 sec);
2701 }
2702
2703 elf_section_type (sec) = SHT_NOTE;
2704 }
2705 }
2706
2707 if (htab->params->cet_report
2708 || htab->params->lam_u48_report
2709 || htab->params->lam_u57_report)
2710 {
2711 /* Report missing IBT, SHSTK and LAM properties. */
2712 bfd *abfd;
2713 const char *warning_msg = _("%P: %pB: warning: missing %s\n");
2714 const char *error_msg = _("%X%P: %pB: error: missing %s\n");
2715 const char *cet_msg = NULL;
2716 const char *lam_u48_msg = NULL;
2717 const char *lam_u57_msg = NULL;
2718 const char *missing;
2719 elf_property_list *p;
2720 bool missing_ibt, missing_shstk;
2721 bool missing_lam_u48, missing_lam_u57;
2722 bool check_ibt
2723 = (htab->params->cet_report
2724 && (htab->params->cet_report & prop_report_ibt));
2725 bool check_shstk
2726 = (htab->params->cet_report
2727 && (htab->params->cet_report & prop_report_shstk));
2728
2729 if (htab->params->cet_report)
2730 {
2731 if ((htab->params->cet_report & prop_report_warning))
2732 cet_msg = warning_msg;
2733 else
2734 cet_msg = error_msg;
2735 }
2736 if (htab->params->lam_u48_report)
2737 {
2738 if ((htab->params->lam_u48_report & prop_report_warning))
2739 lam_u48_msg = warning_msg;
2740 else
2741 lam_u48_msg = error_msg;
2742 }
2743 if (htab->params->lam_u57_report)
2744 {
2745 if ((htab->params->lam_u57_report & prop_report_warning))
2746 lam_u57_msg = warning_msg;
2747 else
2748 lam_u57_msg = error_msg;
2749 }
2750
2751 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
2752 if (!(abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED))
2753 && bfd_get_flavour (abfd) == bfd_target_elf_flavour)
2754 {
2755 for (p = elf_properties (abfd); p; p = p->next)
2756 if (p->property.pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
2757 break;
2758
2759 missing_ibt = check_ibt;
2760 missing_shstk = check_shstk;
2761 missing_lam_u48 = !!lam_u48_msg;
2762 missing_lam_u57 = !!lam_u57_msg;
2763 if (p)
2764 {
2765 missing_ibt &= !(p->property.u.number
2766 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2767 missing_shstk &= !(p->property.u.number
2768 & GNU_PROPERTY_X86_FEATURE_1_SHSTK);
2769 missing_lam_u48 &= !(p->property.u.number
2770 & GNU_PROPERTY_X86_FEATURE_1_LAM_U48);
2771 missing_lam_u57 &= !(p->property.u.number
2772 & GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
2773 }
2774 if (missing_ibt || missing_shstk)
2775 {
2776 if (missing_ibt && missing_shstk)
2777 missing = _("IBT and SHSTK properties");
2778 else if (missing_ibt)
2779 missing = _("IBT property");
2780 else
2781 missing = _("SHSTK property");
2782 info->callbacks->einfo (cet_msg, abfd, missing);
2783 }
2784 if (missing_lam_u48)
2785 {
2786 missing = _("LAM_U48 property");
2787 info->callbacks->einfo (lam_u48_msg, abfd, missing);
2788 }
2789 if (missing_lam_u57)
2790 {
2791 missing = _("LAM_U57 property");
2792 info->callbacks->einfo (lam_u57_msg, abfd, missing);
2793 }
2794 }
2795 }
2796
2797 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2798
2799 htab->r_info = init_table->r_info;
2800 htab->r_sym = init_table->r_sym;
2801
2802 if (bfd_link_relocatable (info))
2803 return pbfd;
2804
2805 htab->plt0_pad_byte = init_table->plt0_pad_byte;
2806
2807 use_ibt_plt = htab->params->ibtplt || htab->params->ibt;
2808 if (!use_ibt_plt && pbfd != NULL)
2809 {
2810 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2811 elf_property_list *p;
2812
2813 /* The property list is sorted in order of type. */
2814 for (p = elf_properties (pbfd); p; p = p->next)
2815 {
2816 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2817 {
2818 use_ibt_plt = !!(p->property.u.number
2819 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2820 break;
2821 }
2822 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2823 break;
2824 }
2825 }
2826
2827 dynobj = htab->elf.dynobj;
2828
2829 /* Set htab->elf.dynobj here so that there is no need to check and
2830 set it in check_relocs. */
2831 if (dynobj == NULL)
2832 {
2833 if (pbfd != NULL)
2834 {
2835 htab->elf.dynobj = pbfd;
2836 dynobj = pbfd;
2837 }
2838 else
2839 {
2840 bfd *abfd;
2841
2842 /* Find a normal input file to hold linker created
2843 sections. */
2844 for (abfd = info->input_bfds;
2845 abfd != NULL;
2846 abfd = abfd->link.next)
2847 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2848 && (abfd->flags
2849 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
2850 && bed->relocs_compatible (abfd->xvec,
2851 info->output_bfd->xvec))
2852 {
2853 htab->elf.dynobj = abfd;
2854 dynobj = abfd;
2855 break;
2856 }
2857 }
2858 }
2859
2860 /* Return if there are no normal input files. */
2861 if (dynobj == NULL)
2862 return pbfd;
2863
2864 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2865 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2866 canonical function address. */
2867 htab->plt.has_plt0 = 1;
2868 normal_target = htab->elf.target_os == is_normal;
2869
2870 if (normal_target)
2871 {
2872 if (use_ibt_plt)
2873 {
2874 htab->lazy_plt = init_table->lazy_ibt_plt;
2875 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2876 }
2877 else
2878 {
2879 htab->lazy_plt = init_table->lazy_plt;
2880 htab->non_lazy_plt = init_table->non_lazy_plt;
2881 }
2882 }
2883 else
2884 {
2885 htab->lazy_plt = init_table->lazy_plt;
2886 htab->non_lazy_plt = NULL;
2887 }
2888
2889 pltsec = htab->elf.splt;
2890
2891 /* If the non-lazy PLT is available, use it for all PLT entries if
2892 there are no PLT0 or no .plt section. */
2893 if (htab->non_lazy_plt != NULL
2894 && (!htab->plt.has_plt0 || pltsec == NULL))
2895 {
2896 lazy_plt = false;
2897 if (bfd_link_pic (info))
2898 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2899 else
2900 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2901 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2902 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2903 htab->plt.plt_got_insn_size
2904 = htab->non_lazy_plt->plt_got_insn_size;
2905 htab->plt.eh_frame_plt_size
2906 = htab->non_lazy_plt->eh_frame_plt_size;
2907 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2908 }
2909 else
2910 {
2911 lazy_plt = true;
2912 if (bfd_link_pic (info))
2913 {
2914 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2915 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2916 }
2917 else
2918 {
2919 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2920 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2921 }
2922 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2923 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2924 htab->plt.plt_got_insn_size
2925 = htab->lazy_plt->plt_got_insn_size;
2926 htab->plt.eh_frame_plt_size
2927 = htab->lazy_plt->eh_frame_plt_size;
2928 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2929 }
2930
2931 if (htab->elf.target_os == is_vxworks
2932 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2933 &htab->srelplt2))
2934 {
2935 info->callbacks->einfo (_("%F%P: failed to create VxWorks dynamic sections\n"));
2936 return pbfd;
2937 }
2938
2939 /* Since create_dynamic_sections isn't always called, but GOT
2940 relocations need GOT relocations, create them here so that we
2941 don't need to do it in check_relocs. */
2942 if (htab->elf.sgot == NULL
2943 && !_bfd_elf_create_got_section (dynobj, info))
2944 info->callbacks->einfo (_("%F%P: failed to create GOT sections\n"));
2945
2946 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2947
2948 /* Align .got and .got.plt sections to their entry size. Do it here
2949 instead of in create_dynamic_sections so that they are always
2950 properly aligned even if create_dynamic_sections isn't called. */
2951 sec = htab->elf.sgot;
2952 if (!bfd_set_section_alignment (sec, got_align))
2953 goto error_alignment;
2954
2955 sec = htab->elf.sgotplt;
2956 if (!bfd_set_section_alignment (sec, got_align))
2957 goto error_alignment;
2958
2959 /* Create the ifunc sections here so that check_relocs can be
2960 simplified. */
2961 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2962 info->callbacks->einfo (_("%F%P: failed to create ifunc sections\n"));
2963
2964 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2965
2966 if (pltsec != NULL)
2967 {
2968 /* Whe creating executable, set the contents of the .interp
2969 section to the interpreter. */
2970 if (bfd_link_executable (info) && !info->nointerp)
2971 {
2972 asection *s = bfd_get_linker_section (dynobj, ".interp");
2973 if (s == NULL)
2974 abort ();
2975 s->size = htab->dynamic_interpreter_size;
2976 s->contents = (unsigned char *) htab->dynamic_interpreter;
2977 htab->interp = s;
2978 }
2979
2980 if (normal_target)
2981 {
2982 flagword pltflags = (bed->dynamic_sec_flags
2983 | SEC_ALLOC
2984 | SEC_CODE
2985 | SEC_LOAD
2986 | SEC_READONLY);
2987 unsigned int non_lazy_plt_alignment
2988 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2989
2990 sec = pltsec;
2991 if (!bfd_set_section_alignment (sec, plt_alignment))
2992 goto error_alignment;
2993
2994 /* Create the GOT procedure linkage table. */
2995 sec = bfd_make_section_anyway_with_flags (dynobj,
2996 ".plt.got",
2997 pltflags);
2998 if (sec == NULL)
2999 info->callbacks->einfo (_("%F%P: failed to create GOT PLT section\n"));
3000
3001 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
3002 goto error_alignment;
3003
3004 htab->plt_got = sec;
3005
3006 if (lazy_plt)
3007 {
3008 sec = NULL;
3009
3010 if (use_ibt_plt)
3011 {
3012 /* Create the second PLT for Intel IBT support. IBT
3013 PLT is needed only for lazy binding. */
3014 sec = bfd_make_section_anyway_with_flags (dynobj,
3015 ".plt.sec",
3016 pltflags);
3017 if (sec == NULL)
3018 info->callbacks->einfo (_("%F%P: failed to create IBT-enabled PLT section\n"));
3019
3020 if (!bfd_set_section_alignment (sec, plt_alignment))
3021 goto error_alignment;
3022 }
3023 else if (htab->params->bndplt && ABI_64_P (dynobj))
3024 {
3025 /* Create the second PLT for Intel MPX support. MPX
3026 PLT is supported only in 64-bit mode and is needed
3027 only for lazy binding. */
3028 sec = bfd_make_section_anyway_with_flags (dynobj,
3029 ".plt.sec",
3030 pltflags);
3031 if (sec == NULL)
3032 info->callbacks->einfo (_("%F%P: failed to create BND PLT section\n"));
3033
3034 if (!bfd_set_section_alignment (sec, non_lazy_plt_alignment))
3035 goto error_alignment;
3036 }
3037
3038 htab->plt_second = sec;
3039 }
3040 }
3041
3042 if (!info->no_ld_generated_unwind_info)
3043 {
3044 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
3045 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
3046 | SEC_LINKER_CREATED);
3047
3048 sec = bfd_make_section_anyway_with_flags (dynobj,
3049 ".eh_frame",
3050 flags);
3051 if (sec == NULL)
3052 info->callbacks->einfo (_("%F%P: failed to create PLT .eh_frame section\n"));
3053
3054 if (!bfd_set_section_alignment (sec, class_align))
3055 goto error_alignment;
3056
3057 htab->plt_eh_frame = sec;
3058
3059 if (htab->plt_got != NULL)
3060 {
3061 sec = bfd_make_section_anyway_with_flags (dynobj,
3062 ".eh_frame",
3063 flags);
3064 if (sec == NULL)
3065 info->callbacks->einfo (_("%F%P: failed to create GOT PLT .eh_frame section\n"));
3066
3067 if (!bfd_set_section_alignment (sec, class_align))
3068 goto error_alignment;
3069
3070 htab->plt_got_eh_frame = sec;
3071 }
3072
3073 if (htab->plt_second != NULL)
3074 {
3075 sec = bfd_make_section_anyway_with_flags (dynobj,
3076 ".eh_frame",
3077 flags);
3078 if (sec == NULL)
3079 info->callbacks->einfo (_("%F%P: failed to create the second PLT .eh_frame section\n"));
3080
3081 if (!bfd_set_section_alignment (sec, class_align))
3082 goto error_alignment;
3083
3084 htab->plt_second_eh_frame = sec;
3085 }
3086 }
3087 }
3088
3089 /* The .iplt section is used for IFUNC symbols in static
3090 executables. */
3091 sec = htab->elf.iplt;
3092 if (sec != NULL)
3093 {
3094 /* NB: Delay setting its alignment until we know it is non-empty.
3095 Otherwise an empty iplt section may change vma and lma of the
3096 following sections, which triggers moving dot of the following
3097 section backwards, resulting in a warning and section lma not
3098 being set properly. It later leads to a "File truncated"
3099 error. */
3100 if (!bfd_set_section_alignment (sec, 0))
3101 goto error_alignment;
3102
3103 htab->plt.iplt_alignment = (normal_target
3104 ? plt_alignment
3105 : bed->plt_alignment);
3106 }
3107
3108 if (bfd_link_executable (info)
3109 && !info->nointerp
3110 && !htab->params->has_dynamic_linker
3111 && htab->params->static_before_all_inputs)
3112 {
3113 /* Report error for dynamic input objects if -static is passed at
3114 command-line before all input files without --dynamic-linker
3115 unless --no-dynamic-linker is used. */
3116 bfd *abfd;
3117
3118 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
3119 if ((abfd->flags & DYNAMIC))
3120 info->callbacks->einfo
3121 (_("%X%P: attempted static link of dynamic object `%pB'\n"),
3122 abfd);
3123 }
3124
3125 return pbfd;
3126 }
3127
3128 /* Fix up x86 GNU properties. */
3129
3130 void
3131 _bfd_x86_elf_link_fixup_gnu_properties
3132 (struct bfd_link_info *info, elf_property_list **listp)
3133 {
3134 elf_property_list *p;
3135
3136 for (p = *listp; p; p = p->next)
3137 {
3138 unsigned int type = p->property.pr_type;
3139 if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
3140 || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3141 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3142 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3143 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3144 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
3145 || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
3146 && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
3147 {
3148 if (p->property.u.number == 0
3149 && (type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
3150 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
3151 && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
3152 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
3153 && type <= GNU_PROPERTY_X86_UINT32_OR_HI)))
3154 {
3155 /* Remove empty property. */
3156 *listp = p->next;
3157 continue;
3158 }
3159
3160 /* Keep LAM features only for 64-bit output. */
3161 if (type == GNU_PROPERTY_X86_FEATURE_1_AND
3162 && !ABI_64_P (info->output_bfd))
3163 p->property.u.number &= ~(GNU_PROPERTY_X86_FEATURE_1_LAM_U48
3164 | GNU_PROPERTY_X86_FEATURE_1_LAM_U57);
3165
3166 listp = &p->next;
3167 }
3168 else if (type > GNU_PROPERTY_HIPROC)
3169 {
3170 /* The property list is sorted in order of type. */
3171 break;
3172 }
3173 }
3174 }
3175
3176 void
3177 _bfd_elf_linker_x86_set_options (struct bfd_link_info * info,
3178 struct elf_linker_x86_params *params)
3179 {
3180 const struct elf_backend_data *bed
3181 = get_elf_backend_data (info->output_bfd);
3182 struct elf_x86_link_hash_table *htab
3183 = elf_x86_hash_table (info, bed->target_id);
3184 if (htab != NULL)
3185 htab->params = params;
3186 }