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[binutils-gdb.git] / bfd / elfxx-x86.c
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1 /* x86 specific support for ELF
2 Copyright (C) 2017 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
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"
27 /* The name of the dynamic interpreter. This is put in the .interp
28 section. */
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"
34 bfd_boolean
35 _bfd_x86_elf_mkobject (bfd *abfd)
37 return bfd_elf_allocate_object (abfd,
38 sizeof (struct elf_x86_obj_tdata),
39 get_elf_backend_data (abfd)->target_id);
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. */
47 void
48 _bfd_x86_elf_set_tls_module_base (struct bfd_link_info *info)
50 struct elf_x86_link_hash_table *htab;
51 struct bfd_link_hash_entry *base;
52 const struct elf_backend_data *bed;
54 if (!bfd_link_executable (info))
55 return;
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;
62 base = htab->tls_module_base;
63 if (base == NULL)
64 return;
66 base->u.def.value = htab->elf.tls_size;
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. */
73 bfd_vma
74 _bfd_x86_elf_dtpoff_base (struct bfd_link_info *info)
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;
82 /* Allocate space in .plt, .got and associated reloc sections for
83 dynamic relocs. */
85 static bfd_boolean
86 elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
88 struct bfd_link_info *info;
89 struct elf_x86_link_hash_table *htab;
90 struct elf_x86_link_hash_entry *eh;
91 struct elf_dyn_relocs *p;
92 unsigned int plt_entry_size;
93 bfd_boolean resolved_to_zero;
94 const struct elf_backend_data *bed;
96 if (h->root.type == bfd_link_hash_indirect)
97 return TRUE;
99 eh = (struct elf_x86_link_hash_entry *) h;
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;
107 plt_entry_size = htab->plt.plt_entry_size;
109 resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
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)
121 /* Don't use the regular PLT if there are both GOT and GOTPLT
122 reloctions. */
123 h->plt.offset = (bfd_vma) -1;
125 /* Use the GOT PLT. */
126 eh->plt_got.refcount = 1;
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)
134 if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs,
135 &htab->readonly_dynrelocs_against_ifunc,
136 plt_entry_size,
137 (htab->plt.has_plt0
138 * plt_entry_size),
139 htab->got_entry_size,
140 TRUE))
142 asection *s = htab->plt_second;
143 if (h->plt.offset != (bfd_vma) -1 && s != NULL)
145 /* Use the second PLT section if it is created. */
146 eh->plt_second.offset = s->size;
148 /* Make room for this entry in the second PLT section. */
149 s->size += htab->non_lazy_plt->plt_entry_size;
152 return TRUE;
154 else
155 return FALSE;
157 /* Don't create the PLT entry if there are only function pointer
158 relocations which can be resolved at run-time. */
159 else if (htab->elf.dynamic_sections_created
160 && (h->plt.refcount > 0
161 || eh->plt_got.refcount > 0))
163 bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
165 /* Make sure this symbol is output as a dynamic symbol.
166 Undefined weak syms won't yet be marked as dynamic. */
167 if (h->dynindx == -1
168 && !h->forced_local
169 && !resolved_to_zero
170 && h->root.type == bfd_link_hash_undefweak)
172 if (! bfd_elf_link_record_dynamic_symbol (info, h))
173 return FALSE;
176 if (bfd_link_pic (info)
177 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
179 asection *s = htab->elf.splt;
180 asection *second_s = htab->plt_second;
181 asection *got_s = htab->plt_got;
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;
189 if (use_plt_got)
190 eh->plt_got.offset = got_s->size;
191 else
193 h->plt.offset = s->size;
194 if (second_s)
195 eh->plt_second.offset = second_s->size;
198 /* If this symbol is not defined in a regular file, and we are
199 not generating a shared library, then set the symbol to this
200 location in the .plt. This is required to make function
201 pointers compare as equal between the normal executable and
202 the shared library. */
203 if (! bfd_link_pic (info)
204 && !h->def_regular)
206 if (use_plt_got)
208 /* We need to make a call to the entry of the GOT PLT
209 instead of regular PLT entry. */
210 h->root.u.def.section = got_s;
211 h->root.u.def.value = eh->plt_got.offset;
213 else
215 if (second_s)
217 /* We need to make a call to the entry of the
218 second PLT instead of regular PLT entry. */
219 h->root.u.def.section = second_s;
220 h->root.u.def.value = eh->plt_second.offset;
222 else
224 h->root.u.def.section = s;
225 h->root.u.def.value = h->plt.offset;
230 /* Make room for this entry. */
231 if (use_plt_got)
232 got_s->size += htab->non_lazy_plt->plt_entry_size;
233 else
235 s->size += plt_entry_size;
236 if (second_s)
237 second_s->size += htab->non_lazy_plt->plt_entry_size;
239 /* We also need to make an entry in the .got.plt section,
240 which will be placed in the .got section by the linker
241 script. */
242 htab->elf.sgotplt->size += htab->got_entry_size;
244 /* There should be no PLT relocation against resolved
245 undefined weak symbol in executable. */
246 if (!resolved_to_zero)
248 /* We also need to make an entry in the .rel.plt
249 section. */
250 htab->elf.srelplt->size += htab->sizeof_reloc;
251 htab->elf.srelplt->reloc_count++;
255 if (htab->target_os == is_vxworks && !bfd_link_pic (info))
257 /* VxWorks has a second set of relocations for each PLT entry
258 in executables. They go in a separate relocation section,
259 which is processed by the kernel loader. */
261 /* There are two relocations for the initial PLT entry: an
262 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
263 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
265 asection *srelplt2 = htab->srelplt2;
266 if (h->plt.offset == plt_entry_size)
267 srelplt2->size += (htab->sizeof_reloc * 2);
269 /* There are two extra relocations for each subsequent PLT entry:
270 an R_386_32 relocation for the GOT entry, and an R_386_32
271 relocation for the PLT entry. */
273 srelplt2->size += (htab->sizeof_reloc * 2);
276 else
278 eh->plt_got.offset = (bfd_vma) -1;
279 h->plt.offset = (bfd_vma) -1;
280 h->needs_plt = 0;
283 else
285 eh->plt_got.offset = (bfd_vma) -1;
286 h->plt.offset = (bfd_vma) -1;
287 h->needs_plt = 0;
290 eh->tlsdesc_got = (bfd_vma) -1;
292 /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the
293 binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For
294 x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary,
295 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
296 if (h->got.refcount > 0
297 && bfd_link_executable (info)
298 && h->dynindx == -1
299 && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
300 h->got.offset = (bfd_vma) -1;
301 else if (h->got.refcount > 0)
303 asection *s;
304 bfd_boolean dyn;
305 int tls_type = elf_x86_hash_entry (h)->tls_type;
307 /* Make sure this symbol is output as a dynamic symbol.
308 Undefined weak syms won't yet be marked as dynamic. */
309 if (h->dynindx == -1
310 && !h->forced_local
311 && !resolved_to_zero
312 && h->root.type == bfd_link_hash_undefweak)
314 if (! bfd_elf_link_record_dynamic_symbol (info, h))
315 return FALSE;
318 s = htab->elf.sgot;
319 if (GOT_TLS_GDESC_P (tls_type))
321 eh->tlsdesc_got = htab->elf.sgotplt->size
322 - elf_x86_compute_jump_table_size (htab);
323 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
324 h->got.offset = (bfd_vma) -2;
326 if (! GOT_TLS_GDESC_P (tls_type)
327 || GOT_TLS_GD_P (tls_type))
329 h->got.offset = s->size;
330 s->size += htab->got_entry_size;
331 /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT
332 slots. */
333 if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
334 s->size += htab->got_entry_size;
336 dyn = htab->elf.dynamic_sections_created;
337 /* R_386_TLS_IE_32 needs one dynamic relocation,
338 R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
339 (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
340 need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local
341 symbol and two if global. No dynamic relocation against
342 resolved undefined weak symbol in executable. */
343 if (tls_type == GOT_TLS_IE_BOTH)
344 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
345 else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
346 || (tls_type & GOT_TLS_IE))
347 htab->elf.srelgot->size += htab->sizeof_reloc;
348 else if (GOT_TLS_GD_P (tls_type))
349 htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
350 else if (! GOT_TLS_GDESC_P (tls_type)
351 && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
352 && !resolved_to_zero)
353 || h->root.type != bfd_link_hash_undefweak)
354 && (bfd_link_pic (info)
355 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
356 htab->elf.srelgot->size += htab->sizeof_reloc;
357 if (GOT_TLS_GDESC_P (tls_type))
359 htab->elf.srelplt->size += htab->sizeof_reloc;
360 if (bed->target_id == X86_64_ELF_DATA)
361 htab->tlsdesc_plt = (bfd_vma) -1;
364 else
365 h->got.offset = (bfd_vma) -1;
367 if (eh->dyn_relocs == NULL)
368 return TRUE;
370 /* In the shared -Bsymbolic case, discard space allocated for
371 dynamic pc-relative relocs against symbols which turn out to be
372 defined in regular objects. For the normal shared case, discard
373 space for pc-relative relocs that have become local due to symbol
374 visibility changes. */
376 if (bfd_link_pic (info))
378 /* Relocs that use pc_count are those that appear on a call
379 insn, or certain REL relocs that can generated via assembly.
380 We want calls to protected symbols to resolve directly to the
381 function rather than going via the plt. If people want
382 function pointer comparisons to work as expected then they
383 should avoid writing weird assembly. */
384 if (SYMBOL_CALLS_LOCAL (info, h))
386 struct elf_dyn_relocs **pp;
388 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
390 p->count -= p->pc_count;
391 p->pc_count = 0;
392 if (p->count == 0)
393 *pp = p->next;
394 else
395 pp = &p->next;
399 if (htab->target_os == is_vxworks)
401 struct elf_dyn_relocs **pp;
402 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
404 if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
405 *pp = p->next;
406 else
407 pp = &p->next;
411 /* Also discard relocs on undefined weak syms with non-default
412 visibility or in PIE. */
413 if (eh->dyn_relocs != NULL)
415 if (h->root.type == bfd_link_hash_undefweak)
417 /* Undefined weak symbol is never bound locally in shared
418 library. */
419 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
420 || resolved_to_zero)
422 if (bed->target_id == I386_ELF_DATA
423 && h->non_got_ref)
425 /* Keep dynamic non-GOT/non-PLT relocation so
426 that we can branch to 0 without PLT. */
427 struct elf_dyn_relocs **pp;
429 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
430 if (p->pc_count == 0)
431 *pp = p->next;
432 else
434 /* Remove non-R_386_PC32 relocation. */
435 p->count = p->pc_count;
436 pp = &p->next;
439 /* Make sure undefined weak symbols are output
440 as dynamic symbols in PIEs for dynamic non-GOT
441 non-PLT reloations. */
442 if (eh->dyn_relocs != NULL
443 && !bfd_elf_link_record_dynamic_symbol (info, h))
444 return FALSE;
446 else
447 eh->dyn_relocs = NULL;
449 else if (h->dynindx == -1
450 && !h->forced_local
451 && !bfd_elf_link_record_dynamic_symbol (info, h))
452 return FALSE;
454 else if (bfd_link_executable (info)
455 && (h->needs_copy || eh->needs_copy)
456 && h->def_dynamic
457 && !h->def_regular)
459 /* NB: needs_copy is set only for x86-64. For PIE,
460 discard space for pc-relative relocs against symbols
461 which turn out to need copy relocs. */
462 struct elf_dyn_relocs **pp;
464 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
466 if (p->pc_count != 0)
467 *pp = p->next;
468 else
469 pp = &p->next;
474 else if (ELIMINATE_COPY_RELOCS)
476 /* For the non-shared case, discard space for relocs against
477 symbols which turn out to need copy relocs or are not
478 dynamic. Keep dynamic relocations for run-time function
479 pointer initialization. */
481 if ((!h->non_got_ref
482 || (h->root.type == bfd_link_hash_undefweak
483 && !resolved_to_zero))
484 && ((h->def_dynamic
485 && !h->def_regular)
486 || (htab->elf.dynamic_sections_created
487 && (h->root.type == bfd_link_hash_undefweak
488 || h->root.type == bfd_link_hash_undefined))))
490 /* Make sure this symbol is output as a dynamic symbol.
491 Undefined weak syms won't yet be marked as dynamic. */
492 if (h->dynindx == -1
493 && !h->forced_local
494 && !resolved_to_zero
495 && h->root.type == bfd_link_hash_undefweak
496 && ! bfd_elf_link_record_dynamic_symbol (info, h))
497 return FALSE;
499 /* If that succeeded, we know we'll be keeping all the
500 relocs. */
501 if (h->dynindx != -1)
502 goto keep;
505 eh->dyn_relocs = NULL;
507 keep: ;
510 /* Finally, allocate space. */
511 for (p = eh->dyn_relocs; p != NULL; p = p->next)
513 asection *sreloc;
515 sreloc = elf_section_data (p->sec)->sreloc;
517 BFD_ASSERT (sreloc != NULL);
518 sreloc->size += p->count * htab->sizeof_reloc;
521 return TRUE;
524 /* Find any dynamic relocs that apply to read-only sections. */
526 bfd_boolean
527 _bfd_x86_elf_readonly_dynrelocs (struct elf_link_hash_entry *h,
528 void *inf)
530 struct elf_x86_link_hash_entry *eh;
531 struct elf_dyn_relocs *p;
533 /* Skip local IFUNC symbols. */
534 if (h->forced_local && h->type == STT_GNU_IFUNC)
535 return TRUE;
537 eh = (struct elf_x86_link_hash_entry *) h;
538 for (p = eh->dyn_relocs; p != NULL; p = p->next)
540 asection *s = p->sec->output_section;
542 if (s != NULL && (s->flags & SEC_READONLY) != 0)
544 struct bfd_link_info *info = (struct bfd_link_info *) inf;
546 info->flags |= DF_TEXTREL;
548 if ((info->warn_shared_textrel && bfd_link_pic (info))
549 || info->error_textrel)
550 /* xgettext:c-format */
551 info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"),
552 p->sec->owner, h->root.root.string,
553 p->sec);
555 /* Not an error, just cut short the traversal. */
556 return FALSE;
559 return TRUE;
562 /* Allocate space in .plt, .got and associated reloc sections for
563 local dynamic relocs. */
565 static bfd_boolean
566 elf_x86_allocate_local_dynreloc (void **slot, void *inf)
568 struct elf_link_hash_entry *h
569 = (struct elf_link_hash_entry *) *slot;
571 if (h->type != STT_GNU_IFUNC
572 || !h->def_regular
573 || !h->ref_regular
574 || !h->forced_local
575 || h->root.type != bfd_link_hash_defined)
576 abort ();
578 return elf_x86_allocate_dynrelocs (h, inf);
581 /* Find and/or create a hash entry for local symbol. */
583 struct elf_link_hash_entry *
584 _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab,
585 bfd *abfd, const Elf_Internal_Rela *rel,
586 bfd_boolean create)
588 struct elf_x86_link_hash_entry e, *ret;
589 asection *sec = abfd->sections;
590 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id,
591 htab->r_sym (rel->r_info));
592 void **slot;
594 e.elf.indx = sec->id;
595 e.elf.dynstr_index = htab->r_sym (rel->r_info);
596 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h,
597 create ? INSERT : NO_INSERT);
599 if (!slot)
600 return NULL;
602 if (*slot)
604 ret = (struct elf_x86_link_hash_entry *) *slot;
605 return &ret->elf;
608 ret = (struct elf_x86_link_hash_entry *)
609 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory,
610 sizeof (struct elf_x86_link_hash_entry));
611 if (ret)
613 memset (ret, 0, sizeof (*ret));
614 ret->elf.indx = sec->id;
615 ret->elf.dynstr_index = htab->r_sym (rel->r_info);
616 ret->elf.dynindx = -1;
617 ret->plt_got.offset = (bfd_vma) -1;
618 *slot = ret;
620 return &ret->elf;
623 /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN
624 SYNC WITH _bfd_elf_link_hash_newfunc. */
626 struct bfd_hash_entry *
627 _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry,
628 struct bfd_hash_table *table,
629 const char *string)
631 /* Allocate the structure if it has not already been allocated by a
632 subclass. */
633 if (entry == NULL)
635 entry = (struct bfd_hash_entry *)
636 bfd_hash_allocate (table,
637 sizeof (struct elf_x86_link_hash_entry));
638 if (entry == NULL)
639 return entry;
642 /* Call the allocation method of the superclass. */
643 entry = _bfd_link_hash_newfunc (entry, table, string);
644 if (entry != NULL)
646 struct elf_x86_link_hash_entry *eh
647 = (struct elf_x86_link_hash_entry *) entry;
648 struct elf_link_hash_table *htab
649 = (struct elf_link_hash_table *) table;
651 memset (&eh->elf.size, 0,
652 (sizeof (struct elf_x86_link_hash_entry)
653 - offsetof (struct elf_link_hash_entry, size)));
654 /* Set local fields. */
655 eh->elf.indx = -1;
656 eh->elf.dynindx = -1;
657 eh->elf.got = htab->init_got_refcount;
658 eh->elf.plt = htab->init_plt_refcount;
659 /* Assume that we have been called by a non-ELF symbol reader.
660 This flag is then reset by the code which reads an ELF input
661 file. This ensures that a symbol created by a non-ELF symbol
662 reader will have the flag set correctly. */
663 eh->elf.non_elf = 1;
664 eh->plt_second.offset = (bfd_vma) -1;
665 eh->plt_got.offset = (bfd_vma) -1;
666 eh->tlsdesc_got = (bfd_vma) -1;
667 eh->zero_undefweak = 1;
670 return entry;
673 /* Compute a hash of a local hash entry. We use elf_link_hash_entry
674 for local symbol so that we can handle local STT_GNU_IFUNC symbols
675 as global symbol. We reuse indx and dynstr_index for local symbol
676 hash since they aren't used by global symbols in this backend. */
678 hashval_t
679 _bfd_x86_elf_local_htab_hash (const void *ptr)
681 struct elf_link_hash_entry *h
682 = (struct elf_link_hash_entry *) ptr;
683 return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index);
686 /* Compare local hash entries. */
689 _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2)
691 struct elf_link_hash_entry *h1
692 = (struct elf_link_hash_entry *) ptr1;
693 struct elf_link_hash_entry *h2
694 = (struct elf_link_hash_entry *) ptr2;
696 return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index;
699 /* Destroy an x86 ELF linker hash table. */
701 static void
702 elf_x86_link_hash_table_free (bfd *obfd)
704 struct elf_x86_link_hash_table *htab
705 = (struct elf_x86_link_hash_table *) obfd->link.hash;
707 if (htab->loc_hash_table)
708 htab_delete (htab->loc_hash_table);
709 if (htab->loc_hash_memory)
710 objalloc_free ((struct objalloc *) htab->loc_hash_memory);
711 _bfd_elf_link_hash_table_free (obfd);
714 static bfd_boolean
715 elf_i386_is_reloc_section (const char *secname)
717 return CONST_STRNEQ (secname, ".rel");
720 static bfd_boolean
721 elf_x86_64_is_reloc_section (const char *secname)
723 return CONST_STRNEQ (secname, ".rela");
726 /* Create an x86 ELF linker hash table. */
728 struct bfd_link_hash_table *
729 _bfd_x86_elf_link_hash_table_create (bfd *abfd)
731 struct elf_x86_link_hash_table *ret;
732 const struct elf_backend_data *bed;
733 bfd_size_type amt = sizeof (struct elf_x86_link_hash_table);
735 ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt);
736 if (ret == NULL)
737 return NULL;
739 bed = get_elf_backend_data (abfd);
740 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd,
741 _bfd_x86_elf_link_hash_newfunc,
742 sizeof (struct elf_x86_link_hash_entry),
743 bed->target_id))
745 free (ret);
746 return NULL;
749 if (bed->target_id == X86_64_ELF_DATA)
751 ret->is_reloc_section = elf_x86_64_is_reloc_section;
752 ret->dt_reloc = DT_RELA;
753 ret->dt_reloc_sz = DT_RELASZ;
754 ret->dt_reloc_ent = DT_RELAENT;
755 ret->got_entry_size = 8;
756 ret->tls_get_addr = "__tls_get_addr";
758 if (ABI_64_P (abfd))
760 ret->sizeof_reloc = sizeof (Elf64_External_Rela);
761 ret->pointer_r_type = R_X86_64_64;
762 ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER;
763 ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER;
765 else
767 if (bed->target_id == X86_64_ELF_DATA)
769 ret->sizeof_reloc = sizeof (Elf32_External_Rela);
770 ret->pointer_r_type = R_X86_64_32;
771 ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER;
772 ret->dynamic_interpreter_size
773 = sizeof ELFX32_DYNAMIC_INTERPRETER;
775 else
777 ret->is_reloc_section = elf_i386_is_reloc_section;
778 ret->dt_reloc = DT_REL;
779 ret->dt_reloc_sz = DT_RELSZ;
780 ret->dt_reloc_ent = DT_RELENT;
781 ret->sizeof_reloc = sizeof (Elf32_External_Rel);
782 ret->got_entry_size = 4;
783 ret->pointer_r_type = R_386_32;
784 ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER;
785 ret->dynamic_interpreter_size
786 = sizeof ELF32_DYNAMIC_INTERPRETER;
787 ret->tls_get_addr = "___tls_get_addr";
790 ret->target_id = bed->target_id;
791 ret->target_os = get_elf_x86_backend_data (abfd)->target_os;
793 ret->loc_hash_table = htab_try_create (1024,
794 _bfd_x86_elf_local_htab_hash,
795 _bfd_x86_elf_local_htab_eq,
796 NULL);
797 ret->loc_hash_memory = objalloc_create ();
798 if (!ret->loc_hash_table || !ret->loc_hash_memory)
800 elf_x86_link_hash_table_free (abfd);
801 return NULL;
803 ret->elf.root.hash_table_free = elf_x86_link_hash_table_free;
805 return &ret->elf.root;
808 /* Sort relocs into address order. */
811 _bfd_x86_elf_compare_relocs (const void *ap, const void *bp)
813 const arelent *a = * (const arelent **) ap;
814 const arelent *b = * (const arelent **) bp;
816 if (a->address > b->address)
817 return 1;
818 else if (a->address < b->address)
819 return -1;
820 else
821 return 0;
824 bfd_boolean
825 _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
827 if (!bfd_link_relocatable (info))
829 /* Check for __tls_get_addr reference. */
830 struct elf_x86_link_hash_table *htab;
831 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
832 htab = elf_x86_hash_table (info, bed->target_id);
833 if (htab)
835 struct elf_link_hash_entry *h;
837 h = elf_link_hash_lookup (elf_hash_table (info),
838 htab->tls_get_addr,
839 FALSE, FALSE, FALSE);
840 if (h != NULL)
841 elf_x86_hash_entry (h)->tls_get_addr = 1;
843 /* "__ehdr_start" will be defined by linker as a hidden symbol
844 later if it is referenced and not defined. */
845 h = elf_link_hash_lookup (elf_hash_table (info),
846 "__ehdr_start",
847 FALSE, FALSE, FALSE);
848 if (h != NULL
849 && (h->root.type == bfd_link_hash_new
850 || h->root.type == bfd_link_hash_undefined
851 || h->root.type == bfd_link_hash_undefweak
852 || h->root.type == bfd_link_hash_common))
854 elf_x86_hash_entry (h)->local_ref = 2;
855 elf_x86_hash_entry (h)->linker_def = 1;
860 /* Invoke the regular ELF backend linker to do all the work. */
861 return _bfd_elf_link_check_relocs (abfd, info);
864 /* Set the sizes of the dynamic sections. */
866 bfd_boolean
867 _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
868 struct bfd_link_info *info)
870 struct elf_x86_link_hash_table *htab;
871 bfd *dynobj;
872 asection *s;
873 bfd_boolean relocs;
874 bfd *ibfd;
875 const struct elf_backend_data *bed
876 = get_elf_backend_data (output_bfd);
878 htab = elf_x86_hash_table (info, bed->target_id);
879 if (htab == NULL)
880 return FALSE;
881 dynobj = htab->elf.dynobj;
882 if (dynobj == NULL)
883 abort ();
885 /* Set up .got offsets for local syms, and space for local dynamic
886 relocs. */
887 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
889 bfd_signed_vma *local_got;
890 bfd_signed_vma *end_local_got;
891 char *local_tls_type;
892 bfd_vma *local_tlsdesc_gotent;
893 bfd_size_type locsymcount;
894 Elf_Internal_Shdr *symtab_hdr;
895 asection *srel;
897 if (! is_x86_elf (ibfd, htab))
898 continue;
900 for (s = ibfd->sections; s != NULL; s = s->next)
902 struct elf_dyn_relocs *p;
904 for (p = ((struct elf_dyn_relocs *)
905 elf_section_data (s)->local_dynrel);
906 p != NULL;
907 p = p->next)
909 if (!bfd_is_abs_section (p->sec)
910 && bfd_is_abs_section (p->sec->output_section))
912 /* Input section has been discarded, either because
913 it is a copy of a linkonce section or due to
914 linker script /DISCARD/, so we'll be discarding
915 the relocs too. */
917 else if (htab->target_os == is_vxworks
918 && strcmp (p->sec->output_section->name,
919 ".tls_vars") == 0)
921 /* Relocations in vxworks .tls_vars sections are
922 handled specially by the loader. */
924 else if (p->count != 0)
926 srel = elf_section_data (p->sec)->sreloc;
927 srel->size += p->count * htab->sizeof_reloc;
928 if ((p->sec->output_section->flags & SEC_READONLY) != 0
929 && (info->flags & DF_TEXTREL) == 0)
931 info->flags |= DF_TEXTREL;
932 if ((info->warn_shared_textrel && bfd_link_pic (info))
933 || info->error_textrel)
934 /* xgettext:c-format */
935 info->callbacks->einfo (_("%P: %B: warning: relocation in readonly section `%A'\n"),
936 p->sec->owner, p->sec);
942 local_got = elf_local_got_refcounts (ibfd);
943 if (!local_got)
944 continue;
946 symtab_hdr = &elf_symtab_hdr (ibfd);
947 locsymcount = symtab_hdr->sh_info;
948 end_local_got = local_got + locsymcount;
949 local_tls_type = elf_x86_local_got_tls_type (ibfd);
950 local_tlsdesc_gotent = elf_x86_local_tlsdesc_gotent (ibfd);
951 s = htab->elf.sgot;
952 srel = htab->elf.srelgot;
953 for (; local_got < end_local_got;
954 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
956 *local_tlsdesc_gotent = (bfd_vma) -1;
957 if (*local_got > 0)
959 if (GOT_TLS_GDESC_P (*local_tls_type))
961 *local_tlsdesc_gotent = htab->elf.sgotplt->size
962 - elf_x86_compute_jump_table_size (htab);
963 htab->elf.sgotplt->size += 2 * htab->got_entry_size;
964 *local_got = (bfd_vma) -2;
966 if (! GOT_TLS_GDESC_P (*local_tls_type)
967 || GOT_TLS_GD_P (*local_tls_type))
969 *local_got = s->size;
970 s->size += htab->got_entry_size;
971 if (GOT_TLS_GD_P (*local_tls_type)
972 || *local_tls_type == GOT_TLS_IE_BOTH)
973 s->size += htab->got_entry_size;
975 if (bfd_link_pic (info)
976 || GOT_TLS_GD_ANY_P (*local_tls_type)
977 || (*local_tls_type & GOT_TLS_IE))
979 if (*local_tls_type == GOT_TLS_IE_BOTH)
980 srel->size += 2 * htab->sizeof_reloc;
981 else if (GOT_TLS_GD_P (*local_tls_type)
982 || ! GOT_TLS_GDESC_P (*local_tls_type))
983 srel->size += htab->sizeof_reloc;
984 if (GOT_TLS_GDESC_P (*local_tls_type))
986 htab->elf.srelplt->size += htab->sizeof_reloc;
987 if (bed->target_id == X86_64_ELF_DATA)
988 htab->tlsdesc_plt = (bfd_vma) -1;
992 else
993 *local_got = (bfd_vma) -1;
997 if (htab->tls_ld_or_ldm_got.refcount > 0)
999 /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM
1000 or R_X86_64_TLSLD relocs. */
1001 htab->tls_ld_or_ldm_got.offset = htab->elf.sgot->size;
1002 htab->elf.sgot->size += 2 * htab->got_entry_size;
1003 htab->elf.srelgot->size += htab->sizeof_reloc;
1005 else
1006 htab->tls_ld_or_ldm_got.offset = -1;
1008 /* Allocate global sym .plt and .got entries, and space for global
1009 sym dynamic relocs. */
1010 elf_link_hash_traverse (&htab->elf, elf_x86_allocate_dynrelocs,
1011 info);
1013 /* Allocate .plt and .got entries, and space for local symbols. */
1014 htab_traverse (htab->loc_hash_table, elf_x86_allocate_local_dynreloc,
1015 info);
1017 /* For every jump slot reserved in the sgotplt, reloc_count is
1018 incremented. However, when we reserve space for TLS descriptors,
1019 it's not incremented, so in order to compute the space reserved
1020 for them, it suffices to multiply the reloc count by the jump
1021 slot size.
1023 PR ld/13302: We start next_irelative_index at the end of .rela.plt
1024 so that R_{386,X86_64}_IRELATIVE entries come last. */
1025 if (htab->elf.srelplt)
1027 htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
1028 htab->sgotplt_jump_table_size
1029 = elf_x86_compute_jump_table_size (htab);
1030 htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
1032 else if (htab->elf.irelplt)
1033 htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
1035 if (htab->tlsdesc_plt)
1037 /* NB: tlsdesc_plt is set only for x86-64. If we're not using
1038 lazy TLS relocations, don't generate the PLT and GOT entries
1039 they require. */
1040 if ((info->flags & DF_BIND_NOW))
1041 htab->tlsdesc_plt = 0;
1042 else
1044 htab->tlsdesc_got = htab->elf.sgot->size;
1045 htab->elf.sgot->size += htab->got_entry_size;
1046 /* Reserve room for the initial entry.
1047 FIXME: we could probably do away with it in this case. */
1048 if (htab->elf.splt->size == 0)
1049 htab->elf.splt->size = htab->plt.plt_entry_size;
1050 htab->tlsdesc_plt = htab->elf.splt->size;
1051 htab->elf.splt->size += htab->plt.plt_entry_size;
1055 if (htab->elf.sgotplt)
1057 /* Don't allocate .got.plt section if there are no GOT nor PLT
1058 entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */
1059 if ((htab->elf.hgot == NULL
1060 || !htab->elf.hgot->ref_regular_nonweak)
1061 && (htab->elf.sgotplt->size == bed->got_header_size)
1062 && (htab->elf.splt == NULL
1063 || htab->elf.splt->size == 0)
1064 && (htab->elf.sgot == NULL
1065 || htab->elf.sgot->size == 0)
1066 && (htab->elf.iplt == NULL
1067 || htab->elf.iplt->size == 0)
1068 && (htab->elf.igotplt == NULL
1069 || htab->elf.igotplt->size == 0))
1070 htab->elf.sgotplt->size = 0;
1073 if (_bfd_elf_eh_frame_present (info))
1075 if (htab->plt_eh_frame != NULL
1076 && htab->elf.splt != NULL
1077 && htab->elf.splt->size != 0
1078 && !bfd_is_abs_section (htab->elf.splt->output_section))
1079 htab->plt_eh_frame->size = htab->plt.eh_frame_plt_size;
1081 if (htab->plt_got_eh_frame != NULL
1082 && htab->plt_got != NULL
1083 && htab->plt_got->size != 0
1084 && !bfd_is_abs_section (htab->plt_got->output_section))
1085 htab->plt_got_eh_frame->size
1086 = htab->non_lazy_plt->eh_frame_plt_size;
1088 /* Unwind info for the second PLT and .plt.got sections are
1089 identical. */
1090 if (htab->plt_second_eh_frame != NULL
1091 && htab->plt_second != NULL
1092 && htab->plt_second->size != 0
1093 && !bfd_is_abs_section (htab->plt_second->output_section))
1094 htab->plt_second_eh_frame->size
1095 = htab->non_lazy_plt->eh_frame_plt_size;
1098 /* We now have determined the sizes of the various dynamic sections.
1099 Allocate memory for them. */
1100 relocs = FALSE;
1101 for (s = dynobj->sections; s != NULL; s = s->next)
1103 bfd_boolean strip_section = TRUE;
1105 if ((s->flags & SEC_LINKER_CREATED) == 0)
1106 continue;
1108 if (s == htab->elf.splt
1109 || s == htab->elf.sgot)
1111 /* Strip this section if we don't need it; see the
1112 comment below. */
1113 /* We'd like to strip these sections if they aren't needed, but if
1114 we've exported dynamic symbols from them we must leave them.
1115 It's too late to tell BFD to get rid of the symbols. */
1117 if (htab->elf.hplt != NULL)
1118 strip_section = FALSE;
1120 else if (s == htab->elf.sgotplt
1121 || s == htab->elf.iplt
1122 || s == htab->elf.igotplt
1123 || s == htab->plt_second
1124 || s == htab->plt_got
1125 || s == htab->plt_eh_frame
1126 || s == htab->plt_got_eh_frame
1127 || s == htab->plt_second_eh_frame
1128 || s == htab->elf.sdynbss
1129 || s == htab->elf.sdynrelro)
1131 /* Strip these too. */
1133 else if (htab->is_reloc_section (bfd_get_section_name (dynobj, s)))
1135 if (s->size != 0
1136 && s != htab->elf.srelplt
1137 && s != htab->srelplt2)
1138 relocs = TRUE;
1140 /* We use the reloc_count field as a counter if we need
1141 to copy relocs into the output file. */
1142 if (s != htab->elf.srelplt)
1143 s->reloc_count = 0;
1145 else
1147 /* It's not one of our sections, so don't allocate space. */
1148 continue;
1151 if (s->size == 0)
1153 /* If we don't need this section, strip it from the
1154 output file. This is mostly to handle .rel.bss and
1155 .rel.plt. We must create both sections in
1156 create_dynamic_sections, because they must be created
1157 before the linker maps input sections to output
1158 sections. The linker does that before
1159 adjust_dynamic_symbol is called, and it is that
1160 function which decides whether anything needs to go
1161 into these sections. */
1162 if (strip_section)
1163 s->flags |= SEC_EXCLUDE;
1164 continue;
1167 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1168 continue;
1170 /* Allocate memory for the section contents. We use bfd_zalloc
1171 here in case unused entries are not reclaimed before the
1172 section's contents are written out. This should not happen,
1173 but this way if it does, we get a R_386_NONE or R_X86_64_NONE
1174 reloc instead of garbage. */
1175 s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size);
1176 if (s->contents == NULL)
1177 return FALSE;
1180 if (htab->plt_eh_frame != NULL
1181 && htab->plt_eh_frame->contents != NULL)
1183 memcpy (htab->plt_eh_frame->contents,
1184 htab->plt.eh_frame_plt,
1185 htab->plt_eh_frame->size);
1186 bfd_put_32 (dynobj, htab->elf.splt->size,
1187 htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET);
1190 if (htab->plt_got_eh_frame != NULL
1191 && htab->plt_got_eh_frame->contents != NULL)
1193 memcpy (htab->plt_got_eh_frame->contents,
1194 htab->non_lazy_plt->eh_frame_plt,
1195 htab->plt_got_eh_frame->size);
1196 bfd_put_32 (dynobj, htab->plt_got->size,
1197 (htab->plt_got_eh_frame->contents
1198 + PLT_FDE_LEN_OFFSET));
1201 if (htab->plt_second_eh_frame != NULL
1202 && htab->plt_second_eh_frame->contents != NULL)
1204 memcpy (htab->plt_second_eh_frame->contents,
1205 htab->non_lazy_plt->eh_frame_plt,
1206 htab->plt_second_eh_frame->size);
1207 bfd_put_32 (dynobj, htab->plt_second->size,
1208 (htab->plt_second_eh_frame->contents
1209 + PLT_FDE_LEN_OFFSET));
1212 if (htab->elf.dynamic_sections_created)
1214 /* Add some entries to the .dynamic section. We fill in the
1215 values later, in elf_{i386,x86_64}_finish_dynamic_sections,
1216 but we must add the entries now so that we get the correct
1217 size for the .dynamic section. The DT_DEBUG entry is filled
1218 in by the dynamic linker and used by the debugger. */
1219 #define add_dynamic_entry(TAG, VAL) \
1220 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1222 if (bfd_link_executable (info))
1224 if (!add_dynamic_entry (DT_DEBUG, 0))
1225 return FALSE;
1228 if (htab->elf.splt->size != 0)
1230 /* DT_PLTGOT is used by prelink even if there is no PLT
1231 relocation. */
1232 if (!add_dynamic_entry (DT_PLTGOT, 0))
1233 return FALSE;
1236 if (htab->elf.srelplt->size != 0)
1238 if (!add_dynamic_entry (DT_PLTRELSZ, 0)
1239 || !add_dynamic_entry (DT_PLTREL, htab->dt_reloc)
1240 || !add_dynamic_entry (DT_JMPREL, 0))
1241 return FALSE;
1244 if (htab->tlsdesc_plt
1245 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
1246 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
1247 return FALSE;
1249 if (relocs)
1251 if (!add_dynamic_entry (htab->dt_reloc, 0)
1252 || !add_dynamic_entry (htab->dt_reloc_sz, 0)
1253 || !add_dynamic_entry (htab->dt_reloc_ent,
1254 htab->sizeof_reloc))
1255 return FALSE;
1257 /* If any dynamic relocs apply to a read-only section,
1258 then we need a DT_TEXTREL entry. */
1259 if ((info->flags & DF_TEXTREL) == 0)
1260 elf_link_hash_traverse (&htab->elf,
1261 _bfd_x86_elf_readonly_dynrelocs,
1262 info);
1264 if ((info->flags & DF_TEXTREL) != 0)
1266 if (htab->readonly_dynrelocs_against_ifunc)
1268 info->callbacks->einfo
1269 (_("%P%X: read-only segment has dynamic IFUNC relocations; recompile with -fPIC\n"));
1270 bfd_set_error (bfd_error_bad_value);
1271 return FALSE;
1274 if (!add_dynamic_entry (DT_TEXTREL, 0))
1275 return FALSE;
1278 if (htab->target_os == is_vxworks
1279 && !elf_vxworks_add_dynamic_entries (output_bfd, info))
1280 return FALSE;
1282 #undef add_dynamic_entry
1284 return TRUE;
1287 /* Finish up the x86 dynamic sections. */
1289 struct elf_x86_link_hash_table *
1290 _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd,
1291 struct bfd_link_info *info)
1293 struct elf_x86_link_hash_table *htab;
1294 const struct elf_backend_data *bed;
1295 bfd *dynobj;
1296 asection *sdyn;
1297 bfd_byte *dyncon, *dynconend;
1298 bfd_size_type sizeof_dyn;
1300 bed = get_elf_backend_data (output_bfd);
1301 htab = elf_x86_hash_table (info, bed->target_id);
1302 if (htab == NULL)
1303 return htab;
1305 dynobj = htab->elf.dynobj;
1306 sdyn = bfd_get_linker_section (dynobj, ".dynamic");
1308 /* GOT is always created in setup_gnu_properties. But it may not be
1309 needed. .got.plt section may be needed for static IFUNC. */
1310 if (htab->elf.sgotplt && htab->elf.sgotplt->size > 0)
1312 bfd_vma dynamic_addr;
1314 if (bfd_is_abs_section (htab->elf.sgotplt->output_section))
1316 _bfd_error_handler
1317 (_("discarded output section: `%A'"), htab->elf.sgotplt);
1318 return NULL;
1321 elf_section_data (htab->elf.sgotplt->output_section)->this_hdr.sh_entsize
1322 = htab->got_entry_size;
1324 dynamic_addr = (sdyn == NULL
1325 ? (bfd_vma) 0
1326 : sdyn->output_section->vma + sdyn->output_offset);
1328 /* Set the first entry in the global offset table to the address
1329 of the dynamic section. Write GOT[1] and GOT[2], needed for
1330 the dynamic linker. */
1331 if (htab->got_entry_size == 8)
1333 bfd_put_64 (output_bfd, dynamic_addr,
1334 htab->elf.sgotplt->contents);
1335 bfd_put_64 (output_bfd, (bfd_vma) 0,
1336 htab->elf.sgotplt->contents + 8);
1337 bfd_put_64 (output_bfd, (bfd_vma) 0,
1338 htab->elf.sgotplt->contents + 8*2);
1340 else
1342 bfd_put_32 (output_bfd, dynamic_addr,
1343 htab->elf.sgotplt->contents);
1344 bfd_put_32 (output_bfd, 0,
1345 htab->elf.sgotplt->contents + 4);
1346 bfd_put_32 (output_bfd, 0,
1347 htab->elf.sgotplt->contents + 4*2);
1351 if (!htab->elf.dynamic_sections_created)
1352 return htab;
1354 if (sdyn == NULL || htab->elf.sgot == NULL)
1355 abort ();
1357 sizeof_dyn = bed->s->sizeof_dyn;
1358 dyncon = sdyn->contents;
1359 dynconend = sdyn->contents + sdyn->size;
1360 for (; dyncon < dynconend; dyncon += sizeof_dyn)
1362 Elf_Internal_Dyn dyn;
1363 asection *s;
1365 (*bed->s->swap_dyn_in) (dynobj, dyncon, &dyn);
1367 switch (dyn.d_tag)
1369 default:
1370 if (htab->target_os == is_vxworks
1371 && elf_vxworks_finish_dynamic_entry (output_bfd, &dyn))
1372 break;
1373 continue;
1375 case DT_PLTGOT:
1376 s = htab->elf.sgotplt;
1377 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
1378 break;
1380 case DT_JMPREL:
1381 dyn.d_un.d_ptr = htab->elf.srelplt->output_section->vma;
1382 break;
1384 case DT_PLTRELSZ:
1385 s = htab->elf.srelplt->output_section;
1386 dyn.d_un.d_val = s->size;
1387 break;
1389 case DT_TLSDESC_PLT:
1390 s = htab->elf.splt;
1391 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
1392 + htab->tlsdesc_plt;
1393 break;
1395 case DT_TLSDESC_GOT:
1396 s = htab->elf.sgot;
1397 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
1398 + htab->tlsdesc_got;
1399 break;
1402 (*bed->s->swap_dyn_out) (output_bfd, &dyn, dyncon);
1405 if (htab->plt_got != NULL && htab->plt_got->size > 0)
1406 elf_section_data (htab->plt_got->output_section)
1407 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size;
1409 if (htab->plt_second != NULL && htab->plt_second->size > 0)
1410 elf_section_data (htab->plt_second->output_section)
1411 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size;
1413 /* Adjust .eh_frame for .plt section. */
1414 if (htab->plt_eh_frame != NULL
1415 && htab->plt_eh_frame->contents != NULL)
1417 if (htab->elf.splt != NULL
1418 && htab->elf.splt->size != 0
1419 && (htab->elf.splt->flags & SEC_EXCLUDE) == 0
1420 && htab->elf.splt->output_section != NULL
1421 && htab->plt_eh_frame->output_section != NULL)
1423 bfd_vma plt_start = htab->elf.splt->output_section->vma;
1424 bfd_vma eh_frame_start = htab->plt_eh_frame->output_section->vma
1425 + htab->plt_eh_frame->output_offset
1426 + PLT_FDE_START_OFFSET;
1427 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1428 htab->plt_eh_frame->contents
1429 + PLT_FDE_START_OFFSET);
1432 if (htab->plt_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
1434 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1435 htab->plt_eh_frame,
1436 htab->plt_eh_frame->contents))
1437 return NULL;
1441 /* Adjust .eh_frame for .plt.got section. */
1442 if (htab->plt_got_eh_frame != NULL
1443 && htab->plt_got_eh_frame->contents != NULL)
1445 if (htab->plt_got != NULL
1446 && htab->plt_got->size != 0
1447 && (htab->plt_got->flags & SEC_EXCLUDE) == 0
1448 && htab->plt_got->output_section != NULL
1449 && htab->plt_got_eh_frame->output_section != NULL)
1451 bfd_vma plt_start = htab->plt_got->output_section->vma;
1452 bfd_vma eh_frame_start = htab->plt_got_eh_frame->output_section->vma
1453 + htab->plt_got_eh_frame->output_offset
1454 + PLT_FDE_START_OFFSET;
1455 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1456 htab->plt_got_eh_frame->contents
1457 + PLT_FDE_START_OFFSET);
1459 if (htab->plt_got_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME)
1461 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1462 htab->plt_got_eh_frame,
1463 htab->plt_got_eh_frame->contents))
1464 return NULL;
1468 /* Adjust .eh_frame for the second PLT section. */
1469 if (htab->plt_second_eh_frame != NULL
1470 && htab->plt_second_eh_frame->contents != NULL)
1472 if (htab->plt_second != NULL
1473 && htab->plt_second->size != 0
1474 && (htab->plt_second->flags & SEC_EXCLUDE) == 0
1475 && htab->plt_second->output_section != NULL
1476 && htab->plt_second_eh_frame->output_section != NULL)
1478 bfd_vma plt_start = htab->plt_second->output_section->vma;
1479 bfd_vma eh_frame_start
1480 = (htab->plt_second_eh_frame->output_section->vma
1481 + htab->plt_second_eh_frame->output_offset
1482 + PLT_FDE_START_OFFSET);
1483 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start,
1484 htab->plt_second_eh_frame->contents
1485 + PLT_FDE_START_OFFSET);
1487 if (htab->plt_second_eh_frame->sec_info_type
1488 == SEC_INFO_TYPE_EH_FRAME)
1490 if (! _bfd_elf_write_section_eh_frame (output_bfd, info,
1491 htab->plt_second_eh_frame,
1492 htab->plt_second_eh_frame->contents))
1493 return NULL;
1497 if (htab->elf.sgot && htab->elf.sgot->size > 0)
1498 elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize
1499 = htab->got_entry_size;
1501 return htab;
1505 bfd_boolean
1506 _bfd_x86_elf_always_size_sections (bfd *output_bfd,
1507 struct bfd_link_info *info)
1509 asection *tls_sec = elf_hash_table (info)->tls_sec;
1511 if (tls_sec)
1513 struct elf_link_hash_entry *tlsbase;
1515 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1516 "_TLS_MODULE_BASE_",
1517 FALSE, FALSE, FALSE);
1519 if (tlsbase && tlsbase->type == STT_TLS)
1521 struct elf_x86_link_hash_table *htab;
1522 struct bfd_link_hash_entry *bh = NULL;
1523 const struct elf_backend_data *bed
1524 = get_elf_backend_data (output_bfd);
1526 htab = elf_x86_hash_table (info, bed->target_id);
1527 if (htab == NULL)
1528 return FALSE;
1530 if (!(_bfd_generic_link_add_one_symbol
1531 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1532 tls_sec, 0, NULL, FALSE,
1533 bed->collect, &bh)))
1534 return FALSE;
1536 htab->tls_module_base = bh;
1538 tlsbase = (struct elf_link_hash_entry *)bh;
1539 tlsbase->def_regular = 1;
1540 tlsbase->other = STV_HIDDEN;
1541 tlsbase->root.linker_def = 1;
1542 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
1546 return TRUE;
1549 void
1550 _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h,
1551 const Elf_Internal_Sym *isym,
1552 bfd_boolean definition,
1553 bfd_boolean dynamic ATTRIBUTE_UNUSED)
1555 if (definition)
1557 struct elf_x86_link_hash_entry *eh
1558 = (struct elf_x86_link_hash_entry *) h;
1559 eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other)
1560 == STV_PROTECTED);
1564 /* Copy the extra info we tack onto an elf_link_hash_entry. */
1566 void
1567 _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info,
1568 struct elf_link_hash_entry *dir,
1569 struct elf_link_hash_entry *ind)
1571 struct elf_x86_link_hash_entry *edir, *eind;
1573 edir = (struct elf_x86_link_hash_entry *) dir;
1574 eind = (struct elf_x86_link_hash_entry *) ind;
1576 if (eind->dyn_relocs != NULL)
1578 if (edir->dyn_relocs != NULL)
1580 struct elf_dyn_relocs **pp;
1581 struct elf_dyn_relocs *p;
1583 /* Add reloc counts against the indirect sym to the direct sym
1584 list. Merge any entries against the same section. */
1585 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
1587 struct elf_dyn_relocs *q;
1589 for (q = edir->dyn_relocs; q != NULL; q = q->next)
1590 if (q->sec == p->sec)
1592 q->pc_count += p->pc_count;
1593 q->count += p->count;
1594 *pp = p->next;
1595 break;
1597 if (q == NULL)
1598 pp = &p->next;
1600 *pp = edir->dyn_relocs;
1603 edir->dyn_relocs = eind->dyn_relocs;
1604 eind->dyn_relocs = NULL;
1607 if (ind->root.type == bfd_link_hash_indirect
1608 && dir->got.refcount <= 0)
1610 edir->tls_type = eind->tls_type;
1611 eind->tls_type = GOT_UNKNOWN;
1614 /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will
1615 generate a R_386_COPY reloc. */
1616 edir->gotoff_ref |= eind->gotoff_ref;
1618 edir->zero_undefweak |= eind->zero_undefweak;
1620 if (ELIMINATE_COPY_RELOCS
1621 && ind->root.type != bfd_link_hash_indirect
1622 && dir->dynamic_adjusted)
1624 /* If called to transfer flags for a weakdef during processing
1625 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
1626 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
1627 if (dir->versioned != versioned_hidden)
1628 dir->ref_dynamic |= ind->ref_dynamic;
1629 dir->ref_regular |= ind->ref_regular;
1630 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
1631 dir->needs_plt |= ind->needs_plt;
1632 dir->pointer_equality_needed |= ind->pointer_equality_needed;
1634 else
1635 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
1638 /* Remove undefined weak symbol from the dynamic symbol table if it
1639 is resolved to 0. */
1641 bfd_boolean
1642 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
1643 struct elf_link_hash_entry *h)
1645 if (h->dynindx != -1
1646 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h)))
1648 h->dynindx = -1;
1649 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
1650 h->dynstr_index);
1652 return TRUE;
1655 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
1657 bfd_boolean
1658 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h)
1660 if (h->plt.offset != (bfd_vma) -1
1661 && !h->def_regular
1662 && !h->pointer_equality_needed)
1663 return FALSE;
1665 return _bfd_elf_hash_symbol (h);
1668 /* Adjust a symbol defined by a dynamic object and referenced by a
1669 regular object. The current definition is in some section of the
1670 dynamic object, but we're not including those sections. We have to
1671 change the definition to something the rest of the link can
1672 understand. */
1674 bfd_boolean
1675 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
1676 struct elf_link_hash_entry *h)
1678 struct elf_x86_link_hash_table *htab;
1679 asection *s, *srel;
1680 struct elf_x86_link_hash_entry *eh;
1681 struct elf_dyn_relocs *p;
1682 const struct elf_backend_data *bed
1683 = get_elf_backend_data (info->output_bfd);
1685 /* STT_GNU_IFUNC symbol must go through PLT. */
1686 if (h->type == STT_GNU_IFUNC)
1688 /* All local STT_GNU_IFUNC references must be treate as local
1689 calls via local PLT. */
1690 if (h->ref_regular
1691 && SYMBOL_CALLS_LOCAL (info, h))
1693 bfd_size_type pc_count = 0, count = 0;
1694 struct elf_dyn_relocs **pp;
1696 eh = (struct elf_x86_link_hash_entry *) h;
1697 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1699 pc_count += p->pc_count;
1700 p->count -= p->pc_count;
1701 p->pc_count = 0;
1702 count += p->count;
1703 if (p->count == 0)
1704 *pp = p->next;
1705 else
1706 pp = &p->next;
1709 if (pc_count || count)
1711 h->non_got_ref = 1;
1712 if (pc_count)
1714 /* Increment PLT reference count only for PC-relative
1715 references. */
1716 h->needs_plt = 1;
1717 if (h->plt.refcount <= 0)
1718 h->plt.refcount = 1;
1719 else
1720 h->plt.refcount += 1;
1725 if (h->plt.refcount <= 0)
1727 h->plt.offset = (bfd_vma) -1;
1728 h->needs_plt = 0;
1730 return TRUE;
1733 /* If this is a function, put it in the procedure linkage table. We
1734 will fill in the contents of the procedure linkage table later,
1735 when we know the address of the .got section. */
1736 if (h->type == STT_FUNC
1737 || h->needs_plt)
1739 if (h->plt.refcount <= 0
1740 || SYMBOL_CALLS_LOCAL (info, h)
1741 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1742 && h->root.type == bfd_link_hash_undefweak))
1744 /* This case can occur if we saw a PLT32 reloc in an input
1745 file, but the symbol was never referred to by a dynamic
1746 object, or if all references were garbage collected. In
1747 such a case, we don't actually need to build a procedure
1748 linkage table, and we can just do a PC32 reloc instead. */
1749 h->plt.offset = (bfd_vma) -1;
1750 h->needs_plt = 0;
1753 return TRUE;
1755 else
1756 /* It's possible that we incorrectly decided a .plt reloc was needed
1757 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in
1758 check_relocs. We can't decide accurately between function and
1759 non-function syms in check-relocs; Objects loaded later in
1760 the link may change h->type. So fix it now. */
1761 h->plt.offset = (bfd_vma) -1;
1763 eh = (struct elf_x86_link_hash_entry *) h;
1765 /* If this is a weak symbol, and there is a real definition, the
1766 processor independent code will have arranged for us to see the
1767 real definition first, and we can just use the same value. */
1768 if (h->u.weakdef != NULL)
1770 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1771 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1772 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1773 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1774 if (ELIMINATE_COPY_RELOCS
1775 || info->nocopyreloc
1776 || SYMBOL_NO_COPYRELOC (info, eh))
1778 /* NB: needs_copy is always 0 for i386. */
1779 h->non_got_ref = h->u.weakdef->non_got_ref;
1780 eh->needs_copy = h->u.weakdef->needs_copy;
1782 return TRUE;
1785 /* This is a reference to a symbol defined by a dynamic object which
1786 is not a function. */
1788 /* If we are creating a shared library, we must presume that the
1789 only references to the symbol are via the global offset table.
1790 For such cases we need not do anything here; the relocations will
1791 be handled correctly by relocate_section. */
1792 if (!bfd_link_executable (info))
1793 return TRUE;
1795 /* If there are no references to this symbol that do not use the
1796 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy
1797 reloc. NB: gotoff_ref is always 0 for x86-64. */
1798 if (!h->non_got_ref && !eh->gotoff_ref)
1799 return TRUE;
1801 /* If -z nocopyreloc was given, we won't generate them either. */
1802 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh))
1804 h->non_got_ref = 0;
1805 return TRUE;
1808 htab = elf_x86_hash_table (info, bed->target_id);
1809 if (htab == NULL)
1810 return FALSE;
1812 /* If there aren't any dynamic relocs in read-only sections nor
1813 R_386_GOTOFF relocation, then we can keep the dynamic relocs and
1814 avoid the copy reloc. This doesn't work on VxWorks, where we can
1815 not have dynamic relocations (other than copy and jump slot
1816 relocations) in an executable. */
1817 if (ELIMINATE_COPY_RELOCS
1818 && (bed->target_id == X86_64_ELF_DATA
1819 || (!eh->gotoff_ref
1820 && htab->target_os != is_vxworks)))
1822 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1824 s = p->sec->output_section;
1825 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1826 break;
1829 /* If we didn't find any dynamic relocs in read-only sections,
1830 then we'll be keeping the dynamic relocs and avoiding the copy
1831 reloc. */
1832 if (p == NULL)
1834 h->non_got_ref = 0;
1835 return TRUE;
1839 /* We must allocate the symbol in our .dynbss section, which will
1840 become part of the .bss section of the executable. There will be
1841 an entry for this symbol in the .dynsym section. The dynamic
1842 object will contain position independent code, so all references
1843 from the dynamic object to this symbol will go through the global
1844 offset table. The dynamic linker will use the .dynsym entry to
1845 determine the address it must put in the global offset table, so
1846 both the dynamic object and the regular object will refer to the
1847 same memory location for the variable. */
1849 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the
1850 dynamic linker to copy the initial value out of the dynamic object
1851 and into the runtime process image. */
1852 if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
1854 s = htab->elf.sdynrelro;
1855 srel = htab->elf.sreldynrelro;
1857 else
1859 s = htab->elf.sdynbss;
1860 srel = htab->elf.srelbss;
1862 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
1864 srel->size += htab->sizeof_reloc;
1865 h->needs_copy = 1;
1868 return _bfd_elf_adjust_dynamic_copy (info, h, s);
1871 void
1872 _bfd_x86_elf_hide_symbol (struct bfd_link_info *info,
1873 struct elf_link_hash_entry *h,
1874 bfd_boolean force_local)
1876 if (h->root.type == bfd_link_hash_undefweak
1877 && info->nointerp
1878 && bfd_link_pie (info))
1880 /* When there is no dynamic interpreter in PIE, make the undefined
1881 weak symbol dynamic so that PC relative branch to the undefined
1882 weak symbol will land to address 0. */
1883 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1884 if (h->plt.refcount > 0
1885 || eh->plt_got.refcount > 0)
1886 return;
1889 _bfd_elf_link_hash_hide_symbol (info, h, force_local);
1892 /* Return TRUE if a symbol is referenced locally. It is similar to
1893 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It
1894 works in check_relocs. */
1896 bfd_boolean
1897 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
1898 struct elf_link_hash_entry *h)
1900 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
1901 struct elf_x86_link_hash_table *htab
1902 = (struct elf_x86_link_hash_table *) info->hash;
1904 if (eh->local_ref > 1)
1905 return TRUE;
1907 if (eh->local_ref == 1)
1908 return FALSE;
1910 /* Unversioned symbols defined in regular objects can be forced local
1911 by linker version script. A weak undefined symbol is forced local
1913 1. It has non-default visibility. Or
1914 2. When building executable, there is no dynamic linker. Or
1915 3. or "-z nodynamic-undefined-weak" is used.
1917 if (SYMBOL_REFERENCES_LOCAL (info, h)
1918 || (h->root.type == bfd_link_hash_undefweak
1919 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1920 || (bfd_link_executable (info)
1921 && htab->interp == NULL)
1922 || info->dynamic_undefined_weak == 0))
1923 || ((h->def_regular || ELF_COMMON_DEF_P (h))
1924 && h->versioned == unversioned
1925 && info->version_info != NULL
1926 && bfd_hide_sym_by_version (info->version_info,
1927 h->root.root.string)))
1929 eh->local_ref = 2;
1930 return TRUE;
1933 eh->local_ref = 1;
1934 return FALSE;
1937 /* Return the section that should be marked against GC for a given
1938 relocation. */
1940 asection *
1941 _bfd_x86_elf_gc_mark_hook (asection *sec,
1942 struct bfd_link_info *info,
1943 Elf_Internal_Rela *rel,
1944 struct elf_link_hash_entry *h,
1945 Elf_Internal_Sym *sym)
1947 /* Compiler should optimize this out. */
1948 if (((unsigned int) R_X86_64_GNU_VTINHERIT
1949 != (unsigned int) R_386_GNU_VTINHERIT)
1950 || ((unsigned int) R_X86_64_GNU_VTENTRY
1951 != (unsigned int) R_386_GNU_VTENTRY))
1952 abort ();
1954 if (h != NULL)
1955 switch (ELF32_R_TYPE (rel->r_info))
1957 case R_X86_64_GNU_VTINHERIT:
1958 case R_X86_64_GNU_VTENTRY:
1959 return NULL;
1962 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
1965 static bfd_vma
1966 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED,
1967 bfd_vma off,
1968 bfd_vma offset ATTRIBUTE_UNUSED,
1969 bfd_vma got_addr)
1971 return got_addr + off;
1974 static bfd_vma
1975 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p,
1976 bfd_vma off,
1977 bfd_vma offset,
1978 bfd_vma got_addr ATTRIBUTE_UNUSED)
1980 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size;
1983 static bfd_boolean
1984 elf_i386_valid_plt_reloc_p (unsigned int type)
1986 return (type == R_386_JUMP_SLOT
1987 || type == R_386_GLOB_DAT
1988 || type == R_386_IRELATIVE);
1991 static bfd_boolean
1992 elf_x86_64_valid_plt_reloc_p (unsigned int type)
1994 return (type == R_X86_64_JUMP_SLOT
1995 || type == R_X86_64_GLOB_DAT
1996 || type == R_X86_64_IRELATIVE);
1999 long
2000 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd,
2001 long count,
2002 long relsize,
2003 bfd_vma got_addr,
2004 struct elf_x86_plt plts[],
2005 asymbol **dynsyms,
2006 asymbol **ret)
2008 long size, i, n, len;
2009 int j;
2010 unsigned int plt_got_offset, plt_entry_size;
2011 asymbol *s;
2012 bfd_byte *plt_contents;
2013 long dynrelcount;
2014 arelent **dynrelbuf, *p;
2015 char *names;
2016 const struct elf_backend_data *bed;
2017 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma,
2018 bfd_vma);
2019 bfd_boolean (*valid_plt_reloc_p) (unsigned int);
2021 if (count == 0)
2022 return -1;
2024 dynrelbuf = (arelent **) bfd_malloc (relsize);
2025 if (dynrelbuf == NULL)
2026 return -1;
2028 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf,
2029 dynsyms);
2030 if (dynrelcount <= 0)
2031 return -1;
2033 /* Sort the relocs by address. */
2034 qsort (dynrelbuf, dynrelcount, sizeof (arelent *),
2035 _bfd_x86_elf_compare_relocs);
2037 size = count * sizeof (asymbol);
2039 /* Allocate space for @plt suffixes. */
2040 n = 0;
2041 for (i = 0; i < dynrelcount; i++)
2043 p = dynrelbuf[i];
2044 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
2045 if (p->addend != 0)
2046 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd);
2049 s = *ret = (asymbol *) bfd_zmalloc (size);
2050 if (s == NULL)
2051 goto bad_return;
2053 bed = get_elf_backend_data (abfd);
2055 if (bed->target_id == X86_64_ELF_DATA)
2057 get_plt_got_vma = elf_x86_64_get_plt_got_vma;
2058 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p;
2060 else
2062 get_plt_got_vma = elf_i386_get_plt_got_vma;
2063 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p;
2064 if (got_addr)
2066 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_
2067 address. */
2068 asection *sec = bfd_get_section_by_name (abfd, ".got.plt");
2069 if (sec != NULL)
2070 got_addr = sec->vma;
2071 else
2073 sec = bfd_get_section_by_name (abfd, ".got");
2074 if (sec != NULL)
2075 got_addr = sec->vma;
2078 if (got_addr == (bfd_vma) -1)
2079 goto bad_return;
2083 /* Check for each PLT section. */
2084 names = (char *) (s + count);
2085 size = 0;
2086 n = 0;
2087 for (j = 0; plts[j].name != NULL; j++)
2088 if ((plt_contents = plts[j].contents) != NULL)
2090 long k;
2091 bfd_vma offset;
2092 asection *plt;
2093 struct elf_x86_plt *plt_p = &plts[j];
2095 plt_got_offset = plt_p->plt_got_offset;
2096 plt_entry_size = plt_p->plt_entry_size;
2098 plt = plt_p->sec;
2100 if ((plt_p->type & plt_lazy))
2102 /* Skip PLT0 in lazy PLT. */
2103 k = 1;
2104 offset = plt_entry_size;
2106 else
2108 k = 0;
2109 offset = 0;
2112 /* Check each PLT entry against dynamic relocations. */
2113 for (; k < plt_p->count; k++)
2115 int off;
2116 bfd_vma got_vma;
2117 long min, max, mid;
2119 /* Get the GOT offset for i386 or the PC-relative offset
2120 for x86-64, a signed 32-bit integer. */
2121 off = H_GET_32 (abfd, (plt_contents + offset
2122 + plt_got_offset));
2123 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr);
2125 /* Binary search. */
2126 p = dynrelbuf[0];
2127 min = 0;
2128 max = dynrelcount;
2129 while ((min + 1) < max)
2131 arelent *r;
2133 mid = (min + max) / 2;
2134 r = dynrelbuf[mid];
2135 if (got_vma > r->address)
2136 min = mid;
2137 else if (got_vma < r->address)
2138 max = mid;
2139 else
2141 p = r;
2142 break;
2146 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */
2147 if (got_vma == p->address
2148 && p->howto != NULL
2149 && valid_plt_reloc_p (p->howto->type))
2151 *s = **p->sym_ptr_ptr;
2152 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL
2153 set. Since we are defining a symbol, ensure one
2154 of them is set. */
2155 if ((s->flags & BSF_LOCAL) == 0)
2156 s->flags |= BSF_GLOBAL;
2157 s->flags |= BSF_SYNTHETIC;
2158 /* This is no longer a section symbol. */
2159 s->flags &= ~BSF_SECTION_SYM;
2160 s->section = plt;
2161 s->the_bfd = plt->owner;
2162 s->value = offset;
2163 s->udata.p = NULL;
2164 s->name = names;
2165 len = strlen ((*p->sym_ptr_ptr)->name);
2166 memcpy (names, (*p->sym_ptr_ptr)->name, len);
2167 names += len;
2168 if (p->addend != 0)
2170 char buf[30], *a;
2172 memcpy (names, "+0x", sizeof ("+0x") - 1);
2173 names += sizeof ("+0x") - 1;
2174 bfd_sprintf_vma (abfd, buf, p->addend);
2175 for (a = buf; *a == '0'; ++a)
2177 size = strlen (a);
2178 memcpy (names, a, size);
2179 names += size;
2181 memcpy (names, "@plt", sizeof ("@plt"));
2182 names += sizeof ("@plt");
2183 n++;
2184 s++;
2185 /* There should be only one entry in PLT for a given
2186 symbol. Set howto to NULL after processing a PLT
2187 entry to guard against corrupted PLT. */
2188 p->howto = NULL;
2190 offset += plt_entry_size;
2194 /* PLT entries with R_386_TLS_DESC relocations are skipped. */
2195 if (n == 0)
2197 bad_return:
2198 count = -1;
2200 else
2201 count = n;
2203 for (j = 0; plts[j].name != NULL; j++)
2204 if (plts[j].contents != NULL)
2205 free (plts[j].contents);
2207 free (dynrelbuf);
2209 return count;
2212 /* Parse x86 GNU properties. */
2214 enum elf_property_kind
2215 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
2216 bfd_byte *ptr, unsigned int datasz)
2218 elf_property *prop;
2220 switch (type)
2222 case GNU_PROPERTY_X86_ISA_1_USED:
2223 case GNU_PROPERTY_X86_ISA_1_NEEDED:
2224 case GNU_PROPERTY_X86_FEATURE_1_AND:
2225 if (datasz != 4)
2227 _bfd_error_handler
2228 ((type == GNU_PROPERTY_X86_ISA_1_USED
2229 ? _("error: %B: <corrupt x86 ISA used size: 0x%x>")
2230 : (type == GNU_PROPERTY_X86_ISA_1_NEEDED
2231 ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>")
2232 : _("error: %B: <corrupt x86 feature size: 0x%x>"))),
2233 abfd, datasz);
2234 return property_corrupt;
2236 prop = _bfd_elf_get_property (abfd, type, datasz);
2237 /* Combine properties of the same type. */
2238 prop->u.number |= bfd_h_get_32 (abfd, ptr);
2239 prop->pr_kind = property_number;
2240 break;
2242 default:
2243 return property_ignored;
2246 return property_number;
2249 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL,
2250 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP
2251 should be merged with ABFD. */
2253 bfd_boolean
2254 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
2255 bfd *abfd ATTRIBUTE_UNUSED,
2256 elf_property *aprop,
2257 elf_property *bprop)
2259 unsigned int number, features;
2260 bfd_boolean updated = FALSE;
2261 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
2263 switch (pr_type)
2265 case GNU_PROPERTY_X86_ISA_1_USED:
2266 case GNU_PROPERTY_X86_ISA_1_NEEDED:
2267 if (aprop != NULL && bprop != NULL)
2269 number = aprop->u.number;
2270 aprop->u.number = number | bprop->u.number;
2271 updated = number != (unsigned int) aprop->u.number;
2273 else
2275 /* Return TRUE if APROP is NULL to indicate that BPROP should
2276 be added to ABFD. */
2277 updated = aprop == NULL;
2279 break;
2281 case GNU_PROPERTY_X86_FEATURE_1_AND:
2282 /* Only one of APROP and BPROP can be NULL:
2283 1. APROP & BPROP when both APROP and BPROP aren't NULL.
2284 2. If APROP is NULL, remove x86 feature.
2285 3. Otherwise, do nothing.
2287 if (aprop != NULL && bprop != NULL)
2289 features = 0;
2290 if (info->ibt)
2291 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2292 if (info->shstk)
2293 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2294 number = aprop->u.number;
2295 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2296 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2297 aprop->u.number = (number & bprop->u.number) | features;
2298 updated = number != (unsigned int) aprop->u.number;
2299 /* Remove the property if all feature bits are cleared. */
2300 if (aprop->u.number == 0)
2301 aprop->pr_kind = property_remove;
2303 else
2305 features = 0;
2306 if (info->ibt)
2307 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2308 if (info->shstk)
2309 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2310 if (features)
2312 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
2313 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2314 if (aprop != NULL)
2316 number = aprop->u.number;
2317 aprop->u.number = number | features;
2318 updated = number != (unsigned int) aprop->u.number;
2320 else
2322 bprop->u.number |= features;
2323 updated = TRUE;
2326 else if (aprop != NULL)
2328 aprop->pr_kind = property_remove;
2329 updated = TRUE;
2332 break;
2334 default:
2335 /* Never should happen. */
2336 abort ();
2339 return updated;
2342 /* Set up x86 GNU properties. Return the first relocatable ELF input
2343 with GNU properties if found. Otherwise, return NULL. */
2345 bfd *
2346 _bfd_x86_elf_link_setup_gnu_properties
2347 (struct bfd_link_info *info, struct elf_x86_init_table *init_table)
2349 bfd_boolean normal_target;
2350 bfd_boolean lazy_plt;
2351 asection *sec, *pltsec;
2352 bfd *dynobj;
2353 bfd_boolean use_ibt_plt;
2354 unsigned int plt_alignment, features;
2355 struct elf_x86_link_hash_table *htab;
2356 bfd *pbfd;
2357 bfd *ebfd = NULL;
2358 elf_property *prop;
2359 const struct elf_backend_data *bed;
2360 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
2361 unsigned int got_align;
2363 features = 0;
2364 if (info->ibt)
2365 features = GNU_PROPERTY_X86_FEATURE_1_IBT;
2366 if (info->shstk)
2367 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2369 /* Find a normal input file with GNU property note. */
2370 for (pbfd = info->input_bfds;
2371 pbfd != NULL;
2372 pbfd = pbfd->link.next)
2373 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
2374 && bfd_count_sections (pbfd) != 0)
2376 ebfd = pbfd;
2378 if (elf_properties (pbfd) != NULL)
2379 break;
2382 if (ebfd != NULL && features)
2384 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
2385 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
2386 prop = _bfd_elf_get_property (ebfd,
2387 GNU_PROPERTY_X86_FEATURE_1_AND,
2389 prop->u.number |= features;
2390 prop->pr_kind = property_number;
2392 /* Create the GNU property note section if needed. */
2393 if (pbfd == NULL)
2395 sec = bfd_make_section_with_flags (ebfd,
2396 NOTE_GNU_PROPERTY_SECTION_NAME,
2397 (SEC_ALLOC
2398 | SEC_LOAD
2399 | SEC_IN_MEMORY
2400 | SEC_READONLY
2401 | SEC_HAS_CONTENTS
2402 | SEC_DATA));
2403 if (sec == NULL)
2404 info->callbacks->einfo (_("%F: failed to create GNU property section\n"));
2406 if (!bfd_set_section_alignment (ebfd, sec, class_align))
2408 error_alignment:
2409 info->callbacks->einfo (_("%F%A: failed to align section\n"),
2410 sec);
2413 elf_section_type (sec) = SHT_NOTE;
2417 pbfd = _bfd_elf_link_setup_gnu_properties (info);
2419 bed = get_elf_backend_data (info->output_bfd);
2421 htab = elf_x86_hash_table (info, bed->target_id);
2422 if (htab == NULL)
2423 return pbfd;
2425 htab->r_info = init_table->r_info;
2426 htab->r_sym = init_table->r_sym;
2428 if (bfd_link_relocatable (info))
2429 return pbfd;
2431 htab->plt0_pad_byte = init_table->plt0_pad_byte;
2433 use_ibt_plt = info->ibtplt || info->ibt;
2434 if (!use_ibt_plt && pbfd != NULL)
2436 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */
2437 elf_property_list *p;
2439 /* The property list is sorted in order of type. */
2440 for (p = elf_properties (pbfd); p; p = p->next)
2442 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
2444 use_ibt_plt = !!(p->property.u.number
2445 & GNU_PROPERTY_X86_FEATURE_1_IBT);
2446 break;
2448 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
2449 break;
2453 dynobj = htab->elf.dynobj;
2455 /* Set htab->elf.dynobj here so that there is no need to check and
2456 set it in check_relocs. */
2457 if (dynobj == NULL)
2459 if (pbfd != NULL)
2461 htab->elf.dynobj = pbfd;
2462 dynobj = pbfd;
2464 else
2466 bfd *abfd;
2468 /* Find a normal input file to hold linker created
2469 sections. */
2470 for (abfd = info->input_bfds;
2471 abfd != NULL;
2472 abfd = abfd->link.next)
2473 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2474 && (abfd->flags
2475 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0)
2477 htab->elf.dynobj = abfd;
2478 dynobj = abfd;
2479 break;
2484 /* Return if there are no normal input files. */
2485 if (dynobj == NULL)
2486 return pbfd;
2488 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
2489 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
2490 canonical function address. */
2491 htab->plt.has_plt0 = 1;
2492 normal_target = htab->target_os == is_normal;
2494 if (normal_target)
2496 if (use_ibt_plt)
2498 htab->lazy_plt = init_table->lazy_ibt_plt;
2499 htab->non_lazy_plt = init_table->non_lazy_ibt_plt;
2501 else
2503 htab->lazy_plt = init_table->lazy_plt;
2504 htab->non_lazy_plt = init_table->non_lazy_plt;
2507 else
2509 htab->lazy_plt = init_table->lazy_plt;
2510 htab->non_lazy_plt = NULL;
2513 pltsec = htab->elf.splt;
2515 /* If the non-lazy PLT is available, use it for all PLT entries if
2516 there are no PLT0 or no .plt section. */
2517 if (htab->non_lazy_plt != NULL
2518 && (!htab->plt.has_plt0 || pltsec == NULL))
2520 lazy_plt = FALSE;
2521 if (bfd_link_pic (info))
2522 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
2523 else
2524 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
2525 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
2526 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
2527 htab->plt.plt_got_insn_size
2528 = htab->non_lazy_plt->plt_got_insn_size;
2529 htab->plt.eh_frame_plt_size
2530 = htab->non_lazy_plt->eh_frame_plt_size;
2531 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
2533 else
2535 lazy_plt = TRUE;
2536 if (bfd_link_pic (info))
2538 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
2539 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
2541 else
2543 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
2544 htab->plt.plt_entry = htab->lazy_plt->plt_entry;
2546 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
2547 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
2548 htab->plt.plt_got_insn_size
2549 = htab->lazy_plt->plt_got_insn_size;
2550 htab->plt.eh_frame_plt_size
2551 = htab->lazy_plt->eh_frame_plt_size;
2552 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
2555 if (htab->target_os == is_vxworks
2556 && !elf_vxworks_create_dynamic_sections (dynobj, info,
2557 &htab->srelplt2))
2559 info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n"));
2560 return pbfd;
2563 /* Since create_dynamic_sections isn't always called, but GOT
2564 relocations need GOT relocations, create them here so that we
2565 don't need to do it in check_relocs. */
2566 if (htab->elf.sgot == NULL
2567 && !_bfd_elf_create_got_section (dynobj, info))
2568 info->callbacks->einfo (_("%F: failed to create GOT sections\n"));
2570 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
2572 /* Align .got and .got.plt sections to their entry size. Do it here
2573 instead of in create_dynamic_sections so that they are always
2574 properly aligned even if create_dynamic_sections isn't called. */
2575 sec = htab->elf.sgot;
2576 if (!bfd_set_section_alignment (dynobj, sec, got_align))
2577 goto error_alignment;
2579 sec = htab->elf.sgotplt;
2580 if (!bfd_set_section_alignment (dynobj, sec, got_align))
2581 goto error_alignment;
2583 /* Create the ifunc sections here so that check_relocs can be
2584 simplified. */
2585 if (!_bfd_elf_create_ifunc_sections (dynobj, info))
2586 info->callbacks->einfo (_("%F: failed to create ifunc sections\n"));
2588 plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
2590 if (pltsec != NULL)
2592 /* Whe creating executable, set the contents of the .interp
2593 section to the interpreter. */
2594 if (bfd_link_executable (info) && !info->nointerp)
2596 asection *s = bfd_get_linker_section (dynobj, ".interp");
2597 if (s == NULL)
2598 abort ();
2599 s->size = htab->dynamic_interpreter_size;
2600 s->contents = (unsigned char *) htab->dynamic_interpreter;
2601 htab->interp = s;
2604 /* Don't change PLT section alignment for NaCl since it uses
2605 64-byte PLT entry and sets PLT section alignment to 32
2606 bytes. Don't create additional PLT sections for NaCl. */
2607 if (normal_target)
2609 flagword pltflags = (bed->dynamic_sec_flags
2610 | SEC_ALLOC
2611 | SEC_CODE
2612 | SEC_LOAD
2613 | SEC_READONLY);
2614 unsigned int non_lazy_plt_alignment
2615 = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
2617 sec = pltsec;
2618 if (!bfd_set_section_alignment (sec->owner, sec,
2619 plt_alignment))
2620 goto error_alignment;
2622 /* Create the GOT procedure linkage table. */
2623 sec = bfd_make_section_anyway_with_flags (dynobj,
2624 ".plt.got",
2625 pltflags);
2626 if (sec == NULL)
2627 info->callbacks->einfo (_("%F: failed to create GOT PLT section\n"));
2629 if (!bfd_set_section_alignment (dynobj, sec,
2630 non_lazy_plt_alignment))
2631 goto error_alignment;
2633 htab->plt_got = sec;
2635 if (lazy_plt)
2637 sec = NULL;
2639 if (use_ibt_plt)
2641 /* Create the second PLT for Intel IBT support. IBT
2642 PLT is supported only for non-NaCl target and is
2643 is needed only for lazy binding. */
2644 sec = bfd_make_section_anyway_with_flags (dynobj,
2645 ".plt.sec",
2646 pltflags);
2647 if (sec == NULL)
2648 info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n"));
2650 if (!bfd_set_section_alignment (dynobj, sec,
2651 plt_alignment))
2652 goto error_alignment;
2654 else if (info->bndplt && ABI_64_P (dynobj))
2656 /* Create the second PLT for Intel MPX support. MPX
2657 PLT is supported only for non-NaCl target in 64-bit
2658 mode and is needed only for lazy binding. */
2659 sec = bfd_make_section_anyway_with_flags (dynobj,
2660 ".plt.sec",
2661 pltflags);
2662 if (sec == NULL)
2663 info->callbacks->einfo (_("%F: failed to create BND PLT section\n"));
2665 if (!bfd_set_section_alignment (dynobj, sec,
2666 non_lazy_plt_alignment))
2667 goto error_alignment;
2670 htab->plt_second = sec;
2674 if (!info->no_ld_generated_unwind_info)
2676 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
2677 | SEC_HAS_CONTENTS | SEC_IN_MEMORY
2678 | SEC_LINKER_CREATED);
2680 sec = bfd_make_section_anyway_with_flags (dynobj,
2681 ".eh_frame",
2682 flags);
2683 if (sec == NULL)
2684 info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n"));
2686 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2687 goto error_alignment;
2689 htab->plt_eh_frame = sec;
2691 if (htab->plt_got != NULL)
2693 sec = bfd_make_section_anyway_with_flags (dynobj,
2694 ".eh_frame",
2695 flags);
2696 if (sec == NULL)
2697 info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n"));
2699 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2700 goto error_alignment;
2702 htab->plt_got_eh_frame = sec;
2705 if (htab->plt_second != NULL)
2707 sec = bfd_make_section_anyway_with_flags (dynobj,
2708 ".eh_frame",
2709 flags);
2710 if (sec == NULL)
2711 info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n"));
2713 if (!bfd_set_section_alignment (dynobj, sec, class_align))
2714 goto error_alignment;
2716 htab->plt_second_eh_frame = sec;
2721 if (normal_target)
2723 /* The .iplt section is used for IFUNC symbols in static
2724 executables. */
2725 sec = htab->elf.iplt;
2726 if (sec != NULL
2727 && !bfd_set_section_alignment (sec->owner, sec,
2728 plt_alignment))
2729 goto error_alignment;
2732 return pbfd;