]>
Commit | Line | Data |
---|---|---|
0afcef53 L |
1 | /* x86 specific support for ELF |
2 | Copyright (C) 2017 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" | |
a6798bab | 22 | #include "elf-vxworks.h" |
765e526c L |
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" | |
0afcef53 | 33 | |
39946cc2 L |
34 | bfd_boolean |
35 | _bfd_x86_elf_mkobject (bfd *abfd) | |
36 | { | |
37 | return bfd_elf_allocate_object (abfd, | |
38 | sizeof (struct elf_x86_obj_tdata), | |
39 | get_elf_backend_data (abfd)->target_id); | |
40 | } | |
41 | ||
0afcef53 L |
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 | /* Find any dynamic relocs that apply to read-only sections. */ | |
83 | ||
84 | bfd_boolean | |
85 | _bfd_x86_elf_readonly_dynrelocs (struct elf_link_hash_entry *h, | |
86 | void *inf) | |
87 | { | |
88 | struct elf_x86_link_hash_entry *eh; | |
89 | struct elf_dyn_relocs *p; | |
90 | ||
91 | /* Skip local IFUNC symbols. */ | |
92 | if (h->forced_local && h->type == STT_GNU_IFUNC) | |
93 | return TRUE; | |
94 | ||
95 | eh = (struct elf_x86_link_hash_entry *) h; | |
96 | for (p = eh->dyn_relocs; p != NULL; p = p->next) | |
97 | { | |
98 | asection *s = p->sec->output_section; | |
99 | ||
100 | if (s != NULL && (s->flags & SEC_READONLY) != 0) | |
101 | { | |
102 | struct bfd_link_info *info = (struct bfd_link_info *) inf; | |
103 | ||
104 | info->flags |= DF_TEXTREL; | |
105 | ||
106 | if ((info->warn_shared_textrel && bfd_link_pic (info)) | |
107 | || info->error_textrel) | |
108 | /* xgettext:c-format */ | |
109 | info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"), | |
110 | p->sec->owner, h->root.root.string, | |
111 | p->sec); | |
112 | ||
113 | /* Not an error, just cut short the traversal. */ | |
114 | return FALSE; | |
115 | } | |
116 | } | |
117 | return TRUE; | |
118 | } | |
119 | ||
120 | /* Find and/or create a hash entry for local symbol. */ | |
121 | ||
122 | struct elf_link_hash_entry * | |
123 | _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab, | |
124 | bfd *abfd, const Elf_Internal_Rela *rel, | |
125 | bfd_boolean create) | |
126 | { | |
127 | struct elf_x86_link_hash_entry e, *ret; | |
128 | asection *sec = abfd->sections; | |
129 | hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id, | |
130 | htab->r_sym (rel->r_info)); | |
131 | void **slot; | |
132 | ||
133 | e.elf.indx = sec->id; | |
134 | e.elf.dynstr_index = htab->r_sym (rel->r_info); | |
135 | slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h, | |
136 | create ? INSERT : NO_INSERT); | |
137 | ||
138 | if (!slot) | |
139 | return NULL; | |
140 | ||
141 | if (*slot) | |
142 | { | |
143 | ret = (struct elf_x86_link_hash_entry *) *slot; | |
144 | return &ret->elf; | |
145 | } | |
146 | ||
147 | ret = (struct elf_x86_link_hash_entry *) | |
148 | objalloc_alloc ((struct objalloc *) htab->loc_hash_memory, | |
149 | sizeof (struct elf_x86_link_hash_entry)); | |
150 | if (ret) | |
151 | { | |
152 | memset (ret, 0, sizeof (*ret)); | |
153 | ret->elf.indx = sec->id; | |
154 | ret->elf.dynstr_index = htab->r_sym (rel->r_info); | |
155 | ret->elf.dynindx = -1; | |
156 | ret->plt_got.offset = (bfd_vma) -1; | |
157 | *slot = ret; | |
158 | } | |
159 | return &ret->elf; | |
160 | } | |
161 | ||
162 | /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN | |
163 | SYNC WITH _bfd_elf_link_hash_newfunc. */ | |
164 | ||
165 | struct bfd_hash_entry * | |
166 | _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry, | |
167 | struct bfd_hash_table *table, | |
168 | const char *string) | |
169 | { | |
170 | /* Allocate the structure if it has not already been allocated by a | |
171 | subclass. */ | |
172 | if (entry == NULL) | |
173 | { | |
174 | entry = (struct bfd_hash_entry *) | |
175 | bfd_hash_allocate (table, | |
176 | sizeof (struct elf_x86_link_hash_entry)); | |
177 | if (entry == NULL) | |
178 | return entry; | |
179 | } | |
180 | ||
181 | /* Call the allocation method of the superclass. */ | |
182 | entry = _bfd_link_hash_newfunc (entry, table, string); | |
183 | if (entry != NULL) | |
184 | { | |
185 | struct elf_x86_link_hash_entry *eh | |
186 | = (struct elf_x86_link_hash_entry *) entry; | |
187 | struct elf_link_hash_table *htab | |
188 | = (struct elf_link_hash_table *) table; | |
189 | ||
190 | memset (&eh->elf.size, 0, | |
191 | (sizeof (struct elf_x86_link_hash_entry) | |
192 | - offsetof (struct elf_link_hash_entry, size))); | |
193 | /* Set local fields. */ | |
194 | eh->elf.indx = -1; | |
195 | eh->elf.dynindx = -1; | |
196 | eh->elf.got = htab->init_got_refcount; | |
197 | eh->elf.plt = htab->init_plt_refcount; | |
198 | /* Assume that we have been called by a non-ELF symbol reader. | |
199 | This flag is then reset by the code which reads an ELF input | |
200 | file. This ensures that a symbol created by a non-ELF symbol | |
201 | reader will have the flag set correctly. */ | |
202 | eh->elf.non_elf = 1; | |
203 | eh->plt_second.offset = (bfd_vma) -1; | |
204 | eh->plt_got.offset = (bfd_vma) -1; | |
205 | eh->tlsdesc_got = (bfd_vma) -1; | |
206 | } | |
207 | ||
208 | return entry; | |
209 | } | |
210 | ||
211 | /* Compute a hash of a local hash entry. We use elf_link_hash_entry | |
212 | for local symbol so that we can handle local STT_GNU_IFUNC symbols | |
213 | as global symbol. We reuse indx and dynstr_index for local symbol | |
214 | hash since they aren't used by global symbols in this backend. */ | |
215 | ||
216 | hashval_t | |
217 | _bfd_x86_elf_local_htab_hash (const void *ptr) | |
218 | { | |
219 | struct elf_link_hash_entry *h | |
220 | = (struct elf_link_hash_entry *) ptr; | |
221 | return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index); | |
222 | } | |
223 | ||
224 | /* Compare local hash entries. */ | |
225 | ||
226 | int | |
227 | _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2) | |
228 | { | |
229 | struct elf_link_hash_entry *h1 | |
230 | = (struct elf_link_hash_entry *) ptr1; | |
231 | struct elf_link_hash_entry *h2 | |
232 | = (struct elf_link_hash_entry *) ptr2; | |
233 | ||
234 | return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index; | |
235 | } | |
236 | ||
237 | /* Destroy an x86 ELF linker hash table. */ | |
238 | ||
765e526c L |
239 | static void |
240 | elf_x86_link_hash_table_free (bfd *obfd) | |
0afcef53 L |
241 | { |
242 | struct elf_x86_link_hash_table *htab | |
243 | = (struct elf_x86_link_hash_table *) obfd->link.hash; | |
244 | ||
245 | if (htab->loc_hash_table) | |
246 | htab_delete (htab->loc_hash_table); | |
247 | if (htab->loc_hash_memory) | |
248 | objalloc_free ((struct objalloc *) htab->loc_hash_memory); | |
249 | _bfd_elf_link_hash_table_free (obfd); | |
250 | } | |
251 | ||
765e526c L |
252 | /* Create an x86 ELF linker hash table. */ |
253 | ||
254 | struct bfd_link_hash_table * | |
255 | _bfd_x86_elf_link_hash_table_create (bfd *abfd) | |
256 | { | |
257 | struct elf_x86_link_hash_table *ret; | |
258 | const struct elf_backend_data *bed; | |
259 | bfd_size_type amt = sizeof (struct elf_x86_link_hash_table); | |
260 | ||
261 | ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt); | |
262 | if (ret == NULL) | |
263 | return NULL; | |
264 | ||
265 | bed = get_elf_backend_data (abfd); | |
266 | if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, | |
267 | _bfd_x86_elf_link_hash_newfunc, | |
268 | sizeof (struct elf_x86_link_hash_entry), | |
269 | bed->target_id)) | |
270 | { | |
271 | free (ret); | |
272 | return NULL; | |
273 | } | |
274 | ||
275 | #ifdef BFD64 | |
276 | if (ABI_64_P (abfd)) | |
277 | { | |
278 | ret->r_info = elf64_r_info; | |
279 | ret->r_sym = elf64_r_sym; | |
503294e7 | 280 | ret->sizeof_reloc = sizeof (Elf64_External_Rela); |
9ff114ca | 281 | ret->got_entry_size = 8; |
765e526c L |
282 | ret->pointer_r_type = R_X86_64_64; |
283 | ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER; | |
284 | ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER; | |
285 | ret->tls_get_addr = "__tls_get_addr"; | |
286 | } | |
287 | else | |
288 | #endif | |
289 | { | |
290 | ret->r_info = elf32_r_info; | |
291 | ret->r_sym = elf32_r_sym; | |
5b86dbf4 | 292 | if (bed->target_id == X86_64_ELF_DATA) |
765e526c | 293 | { |
503294e7 | 294 | ret->sizeof_reloc = sizeof (Elf32_External_Rela); |
9ff114ca | 295 | ret->got_entry_size = 8; |
765e526c L |
296 | ret->pointer_r_type = R_X86_64_32; |
297 | ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER; | |
298 | ret->dynamic_interpreter_size | |
299 | = sizeof ELFX32_DYNAMIC_INTERPRETER; | |
300 | ret->tls_get_addr = "__tls_get_addr"; | |
301 | } | |
302 | else | |
303 | { | |
503294e7 | 304 | ret->sizeof_reloc = sizeof (Elf32_External_Rel); |
9ff114ca | 305 | ret->got_entry_size = 4; |
765e526c L |
306 | ret->pointer_r_type = R_386_32; |
307 | ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER; | |
308 | ret->dynamic_interpreter_size | |
309 | = sizeof ELF32_DYNAMIC_INTERPRETER; | |
310 | ret->tls_get_addr = "___tls_get_addr"; | |
311 | } | |
312 | } | |
fe53b4a4 | 313 | ret->target_id = bed->target_id; |
765e526c L |
314 | |
315 | ret->loc_hash_table = htab_try_create (1024, | |
316 | _bfd_x86_elf_local_htab_hash, | |
317 | _bfd_x86_elf_local_htab_eq, | |
318 | NULL); | |
319 | ret->loc_hash_memory = objalloc_create (); | |
320 | if (!ret->loc_hash_table || !ret->loc_hash_memory) | |
321 | { | |
322 | elf_x86_link_hash_table_free (abfd); | |
323 | return NULL; | |
324 | } | |
325 | ret->elf.root.hash_table_free = elf_x86_link_hash_table_free; | |
326 | ||
327 | return &ret->elf.root; | |
328 | } | |
329 | ||
0afcef53 L |
330 | /* Sort relocs into address order. */ |
331 | ||
332 | int | |
333 | _bfd_x86_elf_compare_relocs (const void *ap, const void *bp) | |
334 | { | |
335 | const arelent *a = * (const arelent **) ap; | |
336 | const arelent *b = * (const arelent **) bp; | |
337 | ||
338 | if (a->address > b->address) | |
339 | return 1; | |
340 | else if (a->address < b->address) | |
341 | return -1; | |
342 | else | |
343 | return 0; | |
344 | } | |
345 | ||
346 | bfd_boolean | |
347 | _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info) | |
348 | { | |
349 | if (!bfd_link_relocatable (info)) | |
350 | { | |
351 | /* Check for __tls_get_addr reference. */ | |
352 | struct elf_x86_link_hash_table *htab; | |
353 | const struct elf_backend_data *bed = get_elf_backend_data (abfd); | |
354 | htab = elf_x86_hash_table (info, bed->target_id); | |
355 | if (htab) | |
356 | { | |
357 | struct elf_link_hash_entry *h | |
358 | = elf_link_hash_lookup (elf_hash_table (info), | |
359 | htab->tls_get_addr, | |
360 | FALSE, FALSE, FALSE); | |
361 | if (h != NULL) | |
362 | ((struct elf_x86_link_hash_entry *) h)->tls_get_addr = 1; | |
363 | } | |
364 | } | |
365 | ||
366 | /* Invoke the regular ELF backend linker to do all the work. */ | |
367 | return _bfd_elf_link_check_relocs (abfd, info); | |
368 | } | |
369 | ||
370 | bfd_boolean | |
371 | _bfd_x86_elf_always_size_sections (bfd *output_bfd, | |
372 | struct bfd_link_info *info) | |
373 | { | |
374 | asection *tls_sec = elf_hash_table (info)->tls_sec; | |
375 | ||
376 | if (tls_sec) | |
377 | { | |
378 | struct elf_link_hash_entry *tlsbase; | |
379 | ||
380 | tlsbase = elf_link_hash_lookup (elf_hash_table (info), | |
381 | "_TLS_MODULE_BASE_", | |
382 | FALSE, FALSE, FALSE); | |
383 | ||
384 | if (tlsbase && tlsbase->type == STT_TLS) | |
385 | { | |
386 | struct elf_x86_link_hash_table *htab; | |
387 | struct bfd_link_hash_entry *bh = NULL; | |
388 | const struct elf_backend_data *bed | |
389 | = get_elf_backend_data (output_bfd); | |
390 | ||
391 | htab = elf_x86_hash_table (info, bed->target_id); | |
392 | if (htab == NULL) | |
393 | return FALSE; | |
394 | ||
395 | if (!(_bfd_generic_link_add_one_symbol | |
396 | (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL, | |
397 | tls_sec, 0, NULL, FALSE, | |
398 | bed->collect, &bh))) | |
399 | return FALSE; | |
400 | ||
401 | htab->tls_module_base = bh; | |
402 | ||
403 | tlsbase = (struct elf_link_hash_entry *)bh; | |
404 | tlsbase->def_regular = 1; | |
405 | tlsbase->other = STV_HIDDEN; | |
406 | tlsbase->root.linker_def = 1; | |
407 | (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); | |
408 | } | |
409 | } | |
410 | ||
411 | return TRUE; | |
412 | } | |
413 | ||
414 | void | |
415 | _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h, | |
416 | const Elf_Internal_Sym *isym, | |
417 | bfd_boolean definition, | |
418 | bfd_boolean dynamic ATTRIBUTE_UNUSED) | |
419 | { | |
420 | if (definition) | |
421 | { | |
422 | struct elf_x86_link_hash_entry *eh | |
423 | = (struct elf_x86_link_hash_entry *) h; | |
424 | eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other) | |
425 | == STV_PROTECTED); | |
426 | } | |
427 | } | |
428 | ||
429 | /* Copy the extra info we tack onto an elf_link_hash_entry. */ | |
430 | ||
431 | void | |
432 | _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info, | |
433 | struct elf_link_hash_entry *dir, | |
434 | struct elf_link_hash_entry *ind) | |
435 | { | |
436 | struct elf_x86_link_hash_entry *edir, *eind; | |
437 | ||
438 | edir = (struct elf_x86_link_hash_entry *) dir; | |
439 | eind = (struct elf_x86_link_hash_entry *) ind; | |
440 | ||
441 | if (eind->dyn_relocs != NULL) | |
442 | { | |
443 | if (edir->dyn_relocs != NULL) | |
444 | { | |
445 | struct elf_dyn_relocs **pp; | |
446 | struct elf_dyn_relocs *p; | |
447 | ||
448 | /* Add reloc counts against the indirect sym to the direct sym | |
449 | list. Merge any entries against the same section. */ | |
450 | for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) | |
451 | { | |
452 | struct elf_dyn_relocs *q; | |
453 | ||
454 | for (q = edir->dyn_relocs; q != NULL; q = q->next) | |
455 | if (q->sec == p->sec) | |
456 | { | |
457 | q->pc_count += p->pc_count; | |
458 | q->count += p->count; | |
459 | *pp = p->next; | |
460 | break; | |
461 | } | |
462 | if (q == NULL) | |
463 | pp = &p->next; | |
464 | } | |
465 | *pp = edir->dyn_relocs; | |
466 | } | |
467 | ||
468 | edir->dyn_relocs = eind->dyn_relocs; | |
469 | eind->dyn_relocs = NULL; | |
470 | } | |
471 | ||
472 | if (ind->root.type == bfd_link_hash_indirect | |
473 | && dir->got.refcount <= 0) | |
474 | { | |
475 | edir->tls_type = eind->tls_type; | |
476 | eind->tls_type = GOT_UNKNOWN; | |
477 | } | |
478 | ||
479 | /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will | |
480 | generate a R_386_COPY reloc. */ | |
481 | edir->gotoff_ref |= eind->gotoff_ref; | |
482 | ||
483 | edir->has_got_reloc |= eind->has_got_reloc; | |
484 | edir->has_non_got_reloc |= eind->has_non_got_reloc; | |
485 | ||
486 | if (ELIMINATE_COPY_RELOCS | |
487 | && ind->root.type != bfd_link_hash_indirect | |
488 | && dir->dynamic_adjusted) | |
489 | { | |
490 | /* If called to transfer flags for a weakdef during processing | |
491 | of elf_adjust_dynamic_symbol, don't copy non_got_ref. | |
492 | We clear it ourselves for ELIMINATE_COPY_RELOCS. */ | |
493 | if (dir->versioned != versioned_hidden) | |
494 | dir->ref_dynamic |= ind->ref_dynamic; | |
495 | dir->ref_regular |= ind->ref_regular; | |
496 | dir->ref_regular_nonweak |= ind->ref_regular_nonweak; | |
497 | dir->needs_plt |= ind->needs_plt; | |
498 | dir->pointer_equality_needed |= ind->pointer_equality_needed; | |
499 | } | |
500 | else | |
501 | { | |
502 | if (eind->func_pointer_refcount > 0) | |
503 | { | |
504 | edir->func_pointer_refcount += eind->func_pointer_refcount; | |
505 | eind->func_pointer_refcount = 0; | |
506 | } | |
507 | ||
508 | _bfd_elf_link_hash_copy_indirect (info, dir, ind); | |
509 | } | |
510 | } | |
511 | ||
512 | /* Remove undefined weak symbol from the dynamic symbol table if it | |
513 | is resolved to 0. */ | |
514 | ||
515 | bfd_boolean | |
516 | _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info, | |
517 | struct elf_link_hash_entry *h) | |
518 | { | |
519 | if (h->dynindx != -1) | |
520 | { | |
521 | const struct elf_backend_data *bed | |
522 | = get_elf_backend_data (info->output_bfd); | |
523 | if (UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, | |
524 | bed->target_id, | |
525 | elf_x86_hash_entry (h)->has_got_reloc, | |
526 | elf_x86_hash_entry (h))) | |
527 | { | |
528 | h->dynindx = -1; | |
529 | _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, | |
530 | h->dynstr_index); | |
531 | } | |
532 | } | |
533 | return TRUE; | |
534 | } | |
535 | ||
536 | /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */ | |
537 | ||
538 | bfd_boolean | |
539 | _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h) | |
540 | { | |
541 | if (h->plt.offset != (bfd_vma) -1 | |
542 | && !h->def_regular | |
543 | && !h->pointer_equality_needed) | |
544 | return FALSE; | |
545 | ||
546 | return _bfd_elf_hash_symbol (h); | |
547 | } | |
548 | ||
eeb2f20a L |
549 | /* Adjust a symbol defined by a dynamic object and referenced by a |
550 | regular object. The current definition is in some section of the | |
551 | dynamic object, but we're not including those sections. We have to | |
552 | change the definition to something the rest of the link can | |
553 | understand. */ | |
554 | ||
555 | bfd_boolean | |
556 | _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info, | |
557 | struct elf_link_hash_entry *h) | |
558 | { | |
559 | struct elf_x86_link_hash_table *htab; | |
560 | asection *s, *srel; | |
561 | struct elf_x86_link_hash_entry *eh; | |
562 | struct elf_dyn_relocs *p; | |
563 | const struct elf_backend_data *bed | |
564 | = get_elf_backend_data (info->output_bfd); | |
565 | ||
566 | /* STT_GNU_IFUNC symbol must go through PLT. */ | |
567 | if (h->type == STT_GNU_IFUNC) | |
568 | { | |
569 | /* All local STT_GNU_IFUNC references must be treate as local | |
570 | calls via local PLT. */ | |
571 | if (h->ref_regular | |
572 | && SYMBOL_CALLS_LOCAL (info, h)) | |
573 | { | |
574 | bfd_size_type pc_count = 0, count = 0; | |
575 | struct elf_dyn_relocs **pp; | |
576 | ||
577 | eh = (struct elf_x86_link_hash_entry *) h; | |
578 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) | |
579 | { | |
580 | pc_count += p->pc_count; | |
581 | p->count -= p->pc_count; | |
582 | p->pc_count = 0; | |
583 | count += p->count; | |
584 | if (p->count == 0) | |
585 | *pp = p->next; | |
586 | else | |
587 | pp = &p->next; | |
588 | } | |
589 | ||
590 | if (pc_count || count) | |
591 | { | |
592 | h->non_got_ref = 1; | |
593 | if (pc_count) | |
594 | { | |
595 | /* Increment PLT reference count only for PC-relative | |
596 | references. */ | |
597 | h->needs_plt = 1; | |
598 | if (h->plt.refcount <= 0) | |
599 | h->plt.refcount = 1; | |
600 | else | |
601 | h->plt.refcount += 1; | |
602 | } | |
603 | } | |
604 | } | |
605 | ||
606 | if (h->plt.refcount <= 0) | |
607 | { | |
608 | h->plt.offset = (bfd_vma) -1; | |
609 | h->needs_plt = 0; | |
610 | } | |
611 | return TRUE; | |
612 | } | |
613 | ||
614 | /* If this is a function, put it in the procedure linkage table. We | |
615 | will fill in the contents of the procedure linkage table later, | |
616 | when we know the address of the .got section. */ | |
617 | if (h->type == STT_FUNC | |
618 | || h->needs_plt) | |
619 | { | |
620 | if (h->plt.refcount <= 0 | |
621 | || SYMBOL_CALLS_LOCAL (info, h) | |
622 | || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT | |
623 | && h->root.type == bfd_link_hash_undefweak)) | |
624 | { | |
625 | /* This case can occur if we saw a PLT32 reloc in an input | |
626 | file, but the symbol was never referred to by a dynamic | |
627 | object, or if all references were garbage collected. In | |
628 | such a case, we don't actually need to build a procedure | |
629 | linkage table, and we can just do a PC32 reloc instead. */ | |
630 | h->plt.offset = (bfd_vma) -1; | |
631 | h->needs_plt = 0; | |
632 | } | |
633 | ||
634 | return TRUE; | |
635 | } | |
636 | else | |
637 | /* It's possible that we incorrectly decided a .plt reloc was needed | |
638 | * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in | |
639 | check_relocs. We can't decide accurately between function and | |
640 | non-function syms in check-relocs; Objects loaded later in | |
641 | the link may change h->type. So fix it now. */ | |
642 | h->plt.offset = (bfd_vma) -1; | |
643 | ||
644 | eh = (struct elf_x86_link_hash_entry *) h; | |
645 | ||
646 | /* If this is a weak symbol, and there is a real definition, the | |
647 | processor independent code will have arranged for us to see the | |
648 | real definition first, and we can just use the same value. */ | |
649 | if (h->u.weakdef != NULL) | |
650 | { | |
651 | BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined | |
652 | || h->u.weakdef->root.type == bfd_link_hash_defweak); | |
653 | h->root.u.def.section = h->u.weakdef->root.u.def.section; | |
654 | h->root.u.def.value = h->u.weakdef->root.u.def.value; | |
655 | if (ELIMINATE_COPY_RELOCS | |
656 | || info->nocopyreloc | |
657 | || SYMBOL_NO_COPYRELOC (info, eh)) | |
658 | { | |
659 | /* NB: needs_copy is always 0 for i386. */ | |
660 | h->non_got_ref = h->u.weakdef->non_got_ref; | |
661 | eh->needs_copy = h->u.weakdef->needs_copy; | |
662 | } | |
663 | return TRUE; | |
664 | } | |
665 | ||
666 | /* This is a reference to a symbol defined by a dynamic object which | |
667 | is not a function. */ | |
668 | ||
669 | /* If we are creating a shared library, we must presume that the | |
670 | only references to the symbol are via the global offset table. | |
671 | For such cases we need not do anything here; the relocations will | |
672 | be handled correctly by relocate_section. */ | |
673 | if (!bfd_link_executable (info)) | |
674 | return TRUE; | |
675 | ||
676 | /* If there are no references to this symbol that do not use the | |
677 | GOT nor R_386_GOTOFF relocation, we don't need to generate a copy | |
678 | reloc. NB: gotoff_ref is always 0 for x86-64. */ | |
679 | if (!h->non_got_ref && !eh->gotoff_ref) | |
680 | return TRUE; | |
681 | ||
682 | /* If -z nocopyreloc was given, we won't generate them either. */ | |
683 | if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh)) | |
684 | { | |
685 | h->non_got_ref = 0; | |
686 | return TRUE; | |
687 | } | |
688 | ||
689 | htab = elf_x86_hash_table (info, bed->target_id); | |
690 | if (htab == NULL) | |
691 | return FALSE; | |
692 | ||
693 | /* If there aren't any dynamic relocs in read-only sections nor | |
694 | R_386_GOTOFF relocation, then we can keep the dynamic relocs and | |
695 | avoid the copy reloc. This doesn't work on VxWorks, where we can | |
696 | not have dynamic relocations (other than copy and jump slot | |
697 | relocations) in an executable. */ | |
698 | if (ELIMINATE_COPY_RELOCS | |
699 | && (bed->target_id == X86_64_ELF_DATA | |
700 | || (!eh->gotoff_ref | |
701 | && !htab->is_vxworks))) | |
702 | { | |
703 | for (p = eh->dyn_relocs; p != NULL; p = p->next) | |
704 | { | |
705 | s = p->sec->output_section; | |
706 | if (s != NULL && (s->flags & SEC_READONLY) != 0) | |
707 | break; | |
708 | } | |
709 | ||
710 | /* If we didn't find any dynamic relocs in read-only sections, | |
711 | then we'll be keeping the dynamic relocs and avoiding the copy | |
712 | reloc. */ | |
713 | if (p == NULL) | |
714 | { | |
715 | h->non_got_ref = 0; | |
716 | return TRUE; | |
717 | } | |
718 | } | |
719 | ||
720 | /* We must allocate the symbol in our .dynbss section, which will | |
721 | become part of the .bss section of the executable. There will be | |
722 | an entry for this symbol in the .dynsym section. The dynamic | |
723 | object will contain position independent code, so all references | |
724 | from the dynamic object to this symbol will go through the global | |
725 | offset table. The dynamic linker will use the .dynsym entry to | |
726 | determine the address it must put in the global offset table, so | |
727 | both the dynamic object and the regular object will refer to the | |
728 | same memory location for the variable. */ | |
729 | ||
730 | /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the | |
731 | dynamic linker to copy the initial value out of the dynamic object | |
732 | and into the runtime process image. */ | |
733 | if ((h->root.u.def.section->flags & SEC_READONLY) != 0) | |
734 | { | |
735 | s = htab->elf.sdynrelro; | |
736 | srel = htab->elf.sreldynrelro; | |
737 | } | |
738 | else | |
739 | { | |
740 | s = htab->elf.sdynbss; | |
741 | srel = htab->elf.srelbss; | |
742 | } | |
743 | if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0) | |
744 | { | |
503294e7 | 745 | srel->size += htab->sizeof_reloc; |
eeb2f20a L |
746 | h->needs_copy = 1; |
747 | } | |
748 | ||
749 | return _bfd_elf_adjust_dynamic_copy (info, h, s); | |
750 | } | |
751 | ||
4f501a24 L |
752 | /* Return the section that should be marked against GC for a given |
753 | relocation. */ | |
754 | ||
755 | asection * | |
756 | _bfd_x86_elf_gc_mark_hook (asection *sec, | |
757 | struct bfd_link_info *info, | |
758 | Elf_Internal_Rela *rel, | |
759 | struct elf_link_hash_entry *h, | |
760 | Elf_Internal_Sym *sym) | |
761 | { | |
762 | /* Compiler should optimize this out. */ | |
763 | if (((unsigned int) R_X86_64_GNU_VTINHERIT | |
764 | != (unsigned int) R_386_GNU_VTINHERIT) | |
765 | || ((unsigned int) R_X86_64_GNU_VTENTRY | |
766 | != (unsigned int) R_386_GNU_VTENTRY)) | |
767 | abort (); | |
768 | ||
769 | if (h != NULL) | |
770 | switch (ELF32_R_TYPE (rel->r_info)) | |
771 | { | |
772 | case R_X86_64_GNU_VTINHERIT: | |
773 | case R_X86_64_GNU_VTENTRY: | |
774 | return NULL; | |
775 | } | |
776 | ||
777 | return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); | |
778 | } | |
779 | ||
f493882d L |
780 | static bfd_vma |
781 | elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED, | |
782 | bfd_vma off, | |
783 | bfd_vma offset ATTRIBUTE_UNUSED, | |
784 | bfd_vma got_addr) | |
785 | { | |
786 | return got_addr + off; | |
787 | } | |
788 | ||
789 | static bfd_vma | |
790 | elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p, | |
791 | bfd_vma off, | |
792 | bfd_vma offset, | |
793 | bfd_vma got_addr ATTRIBUTE_UNUSED) | |
794 | { | |
795 | return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size; | |
796 | } | |
797 | ||
798 | static bfd_boolean | |
799 | elf_i386_valid_plt_reloc_p (unsigned int type) | |
800 | { | |
801 | return (type == R_386_JUMP_SLOT | |
802 | || type == R_386_GLOB_DAT | |
803 | || type == R_386_IRELATIVE); | |
804 | } | |
805 | ||
806 | static bfd_boolean | |
807 | elf_x86_64_valid_plt_reloc_p (unsigned int type) | |
808 | { | |
809 | return (type == R_X86_64_JUMP_SLOT | |
810 | || type == R_X86_64_GLOB_DAT | |
811 | || type == R_X86_64_IRELATIVE); | |
812 | } | |
813 | ||
814 | long | |
815 | _bfd_x86_elf_get_synthetic_symtab (bfd *abfd, | |
816 | long count, | |
817 | long relsize, | |
818 | bfd_vma got_addr, | |
819 | struct elf_x86_plt plts[], | |
820 | asymbol **dynsyms, | |
821 | asymbol **ret) | |
822 | { | |
823 | long size, i, n, len; | |
824 | int j; | |
825 | unsigned int plt_got_offset, plt_entry_size; | |
826 | asymbol *s; | |
827 | bfd_byte *plt_contents; | |
828 | long dynrelcount; | |
829 | arelent **dynrelbuf, *p; | |
830 | char *names; | |
831 | const struct elf_backend_data *bed; | |
832 | bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma, | |
833 | bfd_vma); | |
834 | bfd_boolean (*valid_plt_reloc_p) (unsigned int); | |
835 | ||
836 | if (count == 0) | |
837 | return -1; | |
838 | ||
839 | dynrelbuf = (arelent **) bfd_malloc (relsize); | |
840 | if (dynrelbuf == NULL) | |
841 | return -1; | |
842 | ||
843 | dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf, | |
844 | dynsyms); | |
845 | ||
846 | /* Sort the relocs by address. */ | |
847 | qsort (dynrelbuf, dynrelcount, sizeof (arelent *), | |
848 | _bfd_x86_elf_compare_relocs); | |
849 | ||
850 | size = count * sizeof (asymbol); | |
851 | ||
852 | /* Allocate space for @plt suffixes. */ | |
853 | n = 0; | |
854 | for (i = 0; i < dynrelcount; i++) | |
855 | { | |
856 | p = dynrelbuf[i]; | |
857 | size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt"); | |
858 | if (p->addend != 0) | |
859 | size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd); | |
860 | } | |
861 | ||
862 | s = *ret = (asymbol *) bfd_zmalloc (size); | |
863 | if (s == NULL) | |
864 | goto bad_return; | |
865 | ||
866 | bed = get_elf_backend_data (abfd); | |
867 | ||
868 | if (bed->target_id == X86_64_ELF_DATA) | |
869 | { | |
870 | get_plt_got_vma = elf_x86_64_get_plt_got_vma; | |
871 | valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p; | |
872 | } | |
873 | else | |
874 | { | |
875 | get_plt_got_vma = elf_i386_get_plt_got_vma; | |
876 | valid_plt_reloc_p = elf_i386_valid_plt_reloc_p; | |
877 | if (got_addr) | |
878 | { | |
879 | /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_ | |
880 | address. */ | |
881 | asection *sec = bfd_get_section_by_name (abfd, ".got.plt"); | |
882 | if (sec != NULL) | |
883 | got_addr = sec->vma; | |
884 | else | |
885 | { | |
886 | sec = bfd_get_section_by_name (abfd, ".got"); | |
887 | if (sec != NULL) | |
888 | got_addr = sec->vma; | |
889 | } | |
890 | ||
891 | if (got_addr == (bfd_vma) -1) | |
892 | goto bad_return; | |
893 | } | |
894 | } | |
895 | ||
896 | /* Check for each PLT section. */ | |
897 | names = (char *) (s + count); | |
898 | size = 0; | |
899 | n = 0; | |
900 | for (j = 0; plts[j].name != NULL; j++) | |
901 | if ((plt_contents = plts[j].contents) != NULL) | |
902 | { | |
903 | long k; | |
904 | bfd_vma offset; | |
905 | asection *plt; | |
906 | struct elf_x86_plt *plt_p = &plts[j]; | |
907 | ||
908 | plt_got_offset = plt_p->plt_got_offset; | |
909 | plt_entry_size = plt_p->plt_entry_size; | |
910 | ||
911 | plt = plt_p->sec; | |
912 | ||
913 | if ((plt_p->type & plt_lazy)) | |
914 | { | |
915 | /* Skip PLT0 in lazy PLT. */ | |
916 | k = 1; | |
917 | offset = plt_entry_size; | |
918 | } | |
919 | else | |
920 | { | |
921 | k = 0; | |
922 | offset = 0; | |
923 | } | |
924 | ||
925 | /* Check each PLT entry against dynamic relocations. */ | |
926 | for (; k < plt_p->count; k++) | |
927 | { | |
928 | int off; | |
929 | bfd_vma got_vma; | |
930 | long min, max, mid; | |
931 | ||
932 | /* Get the GOT offset for i386 or the PC-relative offset | |
933 | for x86-64, a signed 32-bit integer. */ | |
934 | off = H_GET_32 (abfd, (plt_contents + offset | |
935 | + plt_got_offset)); | |
936 | got_vma = get_plt_got_vma (plt_p, off, offset, got_addr); | |
937 | ||
938 | /* Binary search. */ | |
939 | p = dynrelbuf[0]; | |
940 | min = 0; | |
941 | max = dynrelcount; | |
942 | while ((min + 1) < max) | |
943 | { | |
944 | arelent *r; | |
945 | ||
946 | mid = (min + max) / 2; | |
947 | r = dynrelbuf[mid]; | |
948 | if (got_vma > r->address) | |
949 | min = mid; | |
950 | else if (got_vma < r->address) | |
951 | max = mid; | |
952 | else | |
953 | { | |
954 | p = r; | |
955 | break; | |
956 | } | |
957 | } | |
958 | ||
959 | /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */ | |
960 | if (got_vma == p->address | |
961 | && p->howto != NULL | |
962 | && valid_plt_reloc_p (p->howto->type)) | |
963 | { | |
964 | *s = **p->sym_ptr_ptr; | |
965 | /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL | |
966 | set. Since we are defining a symbol, ensure one | |
967 | of them is set. */ | |
968 | if ((s->flags & BSF_LOCAL) == 0) | |
969 | s->flags |= BSF_GLOBAL; | |
970 | s->flags |= BSF_SYNTHETIC; | |
971 | /* This is no longer a section symbol. */ | |
972 | s->flags &= ~BSF_SECTION_SYM; | |
973 | s->section = plt; | |
974 | s->the_bfd = plt->owner; | |
975 | s->value = offset; | |
976 | s->udata.p = NULL; | |
977 | s->name = names; | |
978 | len = strlen ((*p->sym_ptr_ptr)->name); | |
979 | memcpy (names, (*p->sym_ptr_ptr)->name, len); | |
980 | names += len; | |
981 | if (p->addend != 0) | |
982 | { | |
983 | char buf[30], *a; | |
984 | ||
985 | memcpy (names, "+0x", sizeof ("+0x") - 1); | |
986 | names += sizeof ("+0x") - 1; | |
987 | bfd_sprintf_vma (abfd, buf, p->addend); | |
988 | for (a = buf; *a == '0'; ++a) | |
989 | ; | |
990 | size = strlen (a); | |
991 | memcpy (names, a, size); | |
992 | names += size; | |
993 | } | |
994 | memcpy (names, "@plt", sizeof ("@plt")); | |
995 | names += sizeof ("@plt"); | |
996 | n++; | |
997 | s++; | |
998 | } | |
999 | offset += plt_entry_size; | |
1000 | } | |
1001 | } | |
1002 | ||
1003 | /* PLT entries with R_386_TLS_DESC relocations are skipped. */ | |
1004 | if (n == 0) | |
1005 | { | |
1006 | bad_return: | |
1007 | count = -1; | |
1008 | } | |
1009 | else | |
1010 | count = n; | |
1011 | ||
1012 | for (j = 0; plts[j].name != NULL; j++) | |
1013 | if (plts[j].contents != NULL) | |
1014 | free (plts[j].contents); | |
1015 | ||
1016 | free (dynrelbuf); | |
1017 | ||
1018 | return count; | |
1019 | } | |
1020 | ||
0afcef53 L |
1021 | /* Parse x86 GNU properties. */ |
1022 | ||
1023 | enum elf_property_kind | |
1024 | _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type, | |
1025 | bfd_byte *ptr, unsigned int datasz) | |
1026 | { | |
1027 | elf_property *prop; | |
1028 | ||
1029 | switch (type) | |
1030 | { | |
1031 | case GNU_PROPERTY_X86_ISA_1_USED: | |
1032 | case GNU_PROPERTY_X86_ISA_1_NEEDED: | |
1033 | case GNU_PROPERTY_X86_FEATURE_1_AND: | |
1034 | if (datasz != 4) | |
1035 | { | |
1036 | _bfd_error_handler | |
1037 | ((type == GNU_PROPERTY_X86_ISA_1_USED | |
1038 | ? _("error: %B: <corrupt x86 ISA used size: 0x%x>") | |
1039 | : (type == GNU_PROPERTY_X86_ISA_1_NEEDED | |
1040 | ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>") | |
1041 | : _("error: %B: <corrupt x86 feature size: 0x%x>"))), | |
1042 | abfd, datasz); | |
1043 | return property_corrupt; | |
1044 | } | |
1045 | prop = _bfd_elf_get_property (abfd, type, datasz); | |
1046 | /* Combine properties of the same type. */ | |
1047 | prop->u.number |= bfd_h_get_32 (abfd, ptr); | |
1048 | prop->pr_kind = property_number; | |
1049 | break; | |
1050 | ||
1051 | default: | |
1052 | return property_ignored; | |
1053 | } | |
1054 | ||
1055 | return property_number; | |
1056 | } | |
1057 | ||
1058 | /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL, | |
1059 | return TRUE if APROP is updated. Otherwise, return TRUE if BPROP | |
1060 | should be merged with ABFD. */ | |
1061 | ||
1062 | bfd_boolean | |
1063 | _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info, | |
1064 | bfd *abfd ATTRIBUTE_UNUSED, | |
1065 | elf_property *aprop, | |
1066 | elf_property *bprop) | |
1067 | { | |
1068 | unsigned int number, features; | |
1069 | bfd_boolean updated = FALSE; | |
1070 | unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type; | |
1071 | ||
1072 | switch (pr_type) | |
1073 | { | |
1074 | case GNU_PROPERTY_X86_ISA_1_USED: | |
1075 | case GNU_PROPERTY_X86_ISA_1_NEEDED: | |
1076 | if (aprop != NULL && bprop != NULL) | |
1077 | { | |
1078 | number = aprop->u.number; | |
1079 | aprop->u.number = number | bprop->u.number; | |
1080 | updated = number != (unsigned int) aprop->u.number; | |
1081 | } | |
1082 | else | |
1083 | { | |
1084 | /* Return TRUE if APROP is NULL to indicate that BPROP should | |
1085 | be added to ABFD. */ | |
1086 | updated = aprop == NULL; | |
1087 | } | |
1088 | break; | |
1089 | ||
1090 | case GNU_PROPERTY_X86_FEATURE_1_AND: | |
1091 | /* Only one of APROP and BPROP can be NULL: | |
1092 | 1. APROP & BPROP when both APROP and BPROP aren't NULL. | |
1093 | 2. If APROP is NULL, remove x86 feature. | |
1094 | 3. Otherwise, do nothing. | |
1095 | */ | |
1096 | if (aprop != NULL && bprop != NULL) | |
1097 | { | |
1098 | features = 0; | |
1099 | if (info->ibt) | |
1100 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; | |
1101 | if (info->shstk) | |
1102 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; | |
1103 | number = aprop->u.number; | |
1104 | /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and | |
1105 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ | |
1106 | aprop->u.number = (number & bprop->u.number) | features; | |
1107 | updated = number != (unsigned int) aprop->u.number; | |
1108 | /* Remove the property if all feature bits are cleared. */ | |
1109 | if (aprop->u.number == 0) | |
1110 | aprop->pr_kind = property_remove; | |
1111 | } | |
1112 | else | |
1113 | { | |
1114 | features = 0; | |
1115 | if (info->ibt) | |
1116 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; | |
1117 | if (info->shstk) | |
1118 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; | |
1119 | if (features) | |
1120 | { | |
1121 | /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and | |
1122 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ | |
1123 | if (aprop != NULL) | |
1124 | { | |
1125 | number = aprop->u.number; | |
1126 | aprop->u.number = number | features; | |
1127 | updated = number != (unsigned int) aprop->u.number; | |
1128 | } | |
1129 | else | |
1130 | { | |
1131 | bprop->u.number |= features; | |
1132 | updated = TRUE; | |
1133 | } | |
1134 | } | |
1135 | else if (aprop != NULL) | |
1136 | { | |
1137 | aprop->pr_kind = property_remove; | |
1138 | updated = TRUE; | |
1139 | } | |
1140 | } | |
1141 | break; | |
1142 | ||
1143 | default: | |
1144 | /* Never should happen. */ | |
1145 | abort (); | |
1146 | } | |
1147 | ||
1148 | return updated; | |
1149 | } | |
a6798bab L |
1150 | |
1151 | /* Set up x86 GNU properties. Return the first relocatable ELF input | |
1152 | with GNU properties if found. Otherwise, return NULL. */ | |
1153 | ||
1154 | bfd * | |
1155 | _bfd_x86_elf_link_setup_gnu_properties | |
1156 | (struct bfd_link_info *info, | |
1157 | struct elf_x86_plt_layout_table *plt_layout) | |
1158 | { | |
1159 | bfd_boolean normal_target; | |
1160 | bfd_boolean lazy_plt; | |
1161 | asection *sec, *pltsec; | |
1162 | bfd *dynobj; | |
1163 | bfd_boolean use_ibt_plt; | |
1164 | unsigned int plt_alignment, features; | |
1165 | struct elf_x86_link_hash_table *htab; | |
1166 | bfd *pbfd; | |
1167 | bfd *ebfd = NULL; | |
1168 | elf_property *prop; | |
1169 | const struct elf_backend_data *bed; | |
1170 | unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2; | |
1171 | unsigned int got_align; | |
1172 | ||
1173 | features = 0; | |
1174 | if (info->ibt) | |
1175 | features = GNU_PROPERTY_X86_FEATURE_1_IBT; | |
1176 | if (info->shstk) | |
1177 | features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; | |
1178 | ||
1179 | /* Find a normal input file with GNU property note. */ | |
1180 | for (pbfd = info->input_bfds; | |
1181 | pbfd != NULL; | |
1182 | pbfd = pbfd->link.next) | |
1183 | if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour | |
1184 | && bfd_count_sections (pbfd) != 0) | |
1185 | { | |
1186 | ebfd = pbfd; | |
1187 | ||
1188 | if (elf_properties (pbfd) != NULL) | |
1189 | break; | |
1190 | } | |
1191 | ||
1192 | if (ebfd != NULL && features) | |
1193 | { | |
1194 | /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and | |
1195 | GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ | |
1196 | prop = _bfd_elf_get_property (ebfd, | |
1197 | GNU_PROPERTY_X86_FEATURE_1_AND, | |
1198 | 4); | |
1199 | prop->u.number |= features; | |
1200 | prop->pr_kind = property_number; | |
1201 | ||
1202 | /* Create the GNU property note section if needed. */ | |
1203 | if (pbfd == NULL) | |
1204 | { | |
1205 | sec = bfd_make_section_with_flags (ebfd, | |
1206 | NOTE_GNU_PROPERTY_SECTION_NAME, | |
1207 | (SEC_ALLOC | |
1208 | | SEC_LOAD | |
1209 | | SEC_IN_MEMORY | |
1210 | | SEC_READONLY | |
1211 | | SEC_HAS_CONTENTS | |
1212 | | SEC_DATA)); | |
1213 | if (sec == NULL) | |
1214 | info->callbacks->einfo (_("%F: failed to create GNU property section\n")); | |
1215 | ||
1216 | if (!bfd_set_section_alignment (ebfd, sec, class_align)) | |
1217 | { | |
1218 | error_alignment: | |
1219 | info->callbacks->einfo (_("%F%A: failed to align section\n"), | |
1220 | sec); | |
1221 | } | |
1222 | ||
1223 | elf_section_type (sec) = SHT_NOTE; | |
1224 | } | |
1225 | } | |
1226 | ||
1227 | pbfd = _bfd_elf_link_setup_gnu_properties (info); | |
1228 | ||
1229 | if (bfd_link_relocatable (info)) | |
1230 | return pbfd; | |
1231 | ||
1232 | bed = get_elf_backend_data (info->output_bfd); | |
1233 | ||
1234 | htab = elf_x86_hash_table (info, bed->target_id); | |
1235 | if (htab == NULL) | |
1236 | return pbfd; | |
1237 | ||
eeb2f20a L |
1238 | htab->is_vxworks = plt_layout->is_vxworks; |
1239 | ||
a6798bab L |
1240 | use_ibt_plt = info->ibtplt || info->ibt; |
1241 | if (!use_ibt_plt && pbfd != NULL) | |
1242 | { | |
1243 | /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */ | |
1244 | elf_property_list *p; | |
1245 | ||
1246 | /* The property list is sorted in order of type. */ | |
1247 | for (p = elf_properties (pbfd); p; p = p->next) | |
1248 | { | |
1249 | if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type) | |
1250 | { | |
1251 | use_ibt_plt = !!(p->property.u.number | |
1252 | & GNU_PROPERTY_X86_FEATURE_1_IBT); | |
1253 | break; | |
1254 | } | |
1255 | else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type) | |
1256 | break; | |
1257 | } | |
1258 | } | |
1259 | ||
1260 | dynobj = htab->elf.dynobj; | |
1261 | ||
1262 | /* Set htab->elf.dynobj here so that there is no need to check and | |
1263 | set it in check_relocs. */ | |
1264 | if (dynobj == NULL) | |
1265 | { | |
1266 | if (pbfd != NULL) | |
1267 | { | |
1268 | htab->elf.dynobj = pbfd; | |
1269 | dynobj = pbfd; | |
1270 | } | |
1271 | else | |
1272 | { | |
1273 | bfd *abfd; | |
1274 | ||
1275 | /* Find a normal input file to hold linker created | |
1276 | sections. */ | |
1277 | for (abfd = info->input_bfds; | |
1278 | abfd != NULL; | |
1279 | abfd = abfd->link.next) | |
1280 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour | |
1281 | && (abfd->flags | |
1282 | & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0) | |
1283 | { | |
1284 | htab->elf.dynobj = abfd; | |
1285 | dynobj = abfd; | |
1286 | break; | |
1287 | } | |
1288 | } | |
1289 | } | |
1290 | ||
1291 | /* Even when lazy binding is disabled by "-z now", the PLT0 entry may | |
1292 | still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for | |
1293 | canonical function address. */ | |
1294 | htab->plt.has_plt0 = 1; | |
1295 | normal_target = plt_layout->normal_target; | |
1296 | ||
1297 | if (normal_target) | |
1298 | { | |
1299 | if (use_ibt_plt) | |
1300 | { | |
1301 | htab->lazy_plt = plt_layout->lazy_ibt_plt; | |
1302 | htab->non_lazy_plt = plt_layout->non_lazy_ibt_plt; | |
1303 | } | |
1304 | else | |
1305 | { | |
1306 | htab->lazy_plt = plt_layout->lazy_plt; | |
1307 | htab->non_lazy_plt = plt_layout->non_lazy_plt; | |
1308 | } | |
1309 | } | |
1310 | else | |
1311 | { | |
1312 | htab->lazy_plt = plt_layout->lazy_plt; | |
1313 | htab->non_lazy_plt = NULL; | |
1314 | } | |
1315 | ||
1316 | pltsec = htab->elf.splt; | |
1317 | ||
1318 | /* If the non-lazy PLT is available, use it for all PLT entries if | |
1319 | there are no PLT0 or no .plt section. */ | |
1320 | if (htab->non_lazy_plt != NULL | |
1321 | && (!htab->plt.has_plt0 || pltsec == NULL)) | |
1322 | { | |
1323 | lazy_plt = FALSE; | |
1324 | if (bfd_link_pic (info)) | |
1325 | htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry; | |
1326 | else | |
1327 | htab->plt.plt_entry = htab->non_lazy_plt->plt_entry; | |
1328 | htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size; | |
1329 | htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset; | |
1330 | htab->plt.plt_got_insn_size | |
1331 | = htab->non_lazy_plt->plt_got_insn_size; | |
1332 | htab->plt.eh_frame_plt_size | |
1333 | = htab->non_lazy_plt->eh_frame_plt_size; | |
1334 | htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt; | |
1335 | } | |
1336 | else | |
1337 | { | |
1338 | lazy_plt = TRUE; | |
1339 | if (bfd_link_pic (info)) | |
1340 | { | |
1341 | htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry; | |
1342 | htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry; | |
1343 | } | |
1344 | else | |
1345 | { | |
1346 | htab->plt.plt0_entry = htab->lazy_plt->plt0_entry; | |
1347 | htab->plt.plt_entry = htab->lazy_plt->plt_entry; | |
1348 | } | |
1349 | htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size; | |
1350 | htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset; | |
1351 | htab->plt.plt_got_insn_size | |
1352 | = htab->lazy_plt->plt_got_insn_size; | |
1353 | htab->plt.eh_frame_plt_size | |
1354 | = htab->lazy_plt->eh_frame_plt_size; | |
1355 | htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt; | |
1356 | } | |
1357 | ||
1358 | /* Return if there are no normal input files. */ | |
1359 | if (dynobj == NULL) | |
1360 | return pbfd; | |
1361 | ||
eeb2f20a | 1362 | if (htab->is_vxworks |
a6798bab L |
1363 | && !elf_vxworks_create_dynamic_sections (dynobj, info, |
1364 | &htab->srelplt2)) | |
1365 | { | |
1366 | info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n")); | |
1367 | return pbfd; | |
1368 | } | |
1369 | ||
1370 | /* Since create_dynamic_sections isn't always called, but GOT | |
1371 | relocations need GOT relocations, create them here so that we | |
1372 | don't need to do it in check_relocs. */ | |
1373 | if (htab->elf.sgot == NULL | |
1374 | && !_bfd_elf_create_got_section (dynobj, info)) | |
1375 | info->callbacks->einfo (_("%F: failed to create GOT sections\n")); | |
1376 | ||
1377 | got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2; | |
1378 | ||
1379 | /* Align .got and .got.plt sections to their entry size. Do it here | |
1380 | instead of in create_dynamic_sections so that they are always | |
1381 | properly aligned even if create_dynamic_sections isn't called. */ | |
1382 | sec = htab->elf.sgot; | |
1383 | if (!bfd_set_section_alignment (dynobj, sec, got_align)) | |
1384 | goto error_alignment; | |
1385 | ||
1386 | sec = htab->elf.sgotplt; | |
1387 | if (!bfd_set_section_alignment (dynobj, sec, got_align)) | |
1388 | goto error_alignment; | |
1389 | ||
1390 | /* Create the ifunc sections here so that check_relocs can be | |
1391 | simplified. */ | |
1392 | if (!_bfd_elf_create_ifunc_sections (dynobj, info)) | |
1393 | info->callbacks->einfo (_("%F: failed to create ifunc sections\n")); | |
1394 | ||
1395 | plt_alignment = bfd_log2 (htab->plt.plt_entry_size); | |
1396 | ||
1397 | if (pltsec != NULL) | |
1398 | { | |
1399 | /* Whe creating executable, set the contents of the .interp | |
1400 | section to the interpreter. */ | |
1401 | if (bfd_link_executable (info) && !info->nointerp) | |
1402 | { | |
1403 | asection *s = bfd_get_linker_section (dynobj, ".interp"); | |
1404 | if (s == NULL) | |
1405 | abort (); | |
1406 | s->size = htab->dynamic_interpreter_size; | |
1407 | s->contents = (unsigned char *) htab->dynamic_interpreter; | |
1408 | htab->interp = s; | |
1409 | } | |
1410 | ||
1411 | /* Don't change PLT section alignment for NaCl since it uses | |
1412 | 64-byte PLT entry and sets PLT section alignment to 32 | |
1413 | bytes. Don't create additional PLT sections for NaCl. */ | |
1414 | if (normal_target) | |
1415 | { | |
1416 | flagword pltflags = (bed->dynamic_sec_flags | |
1417 | | SEC_ALLOC | |
1418 | | SEC_CODE | |
1419 | | SEC_LOAD | |
1420 | | SEC_READONLY); | |
1421 | unsigned int non_lazy_plt_alignment | |
1422 | = bfd_log2 (htab->non_lazy_plt->plt_entry_size); | |
1423 | ||
1424 | sec = pltsec; | |
1425 | if (!bfd_set_section_alignment (sec->owner, sec, | |
1426 | plt_alignment)) | |
1427 | goto error_alignment; | |
1428 | ||
1429 | /* Create the GOT procedure linkage table. */ | |
1430 | sec = bfd_make_section_anyway_with_flags (dynobj, | |
1431 | ".plt.got", | |
1432 | pltflags); | |
1433 | if (sec == NULL) | |
1434 | info->callbacks->einfo (_("%F: failed to create GOT PLT section\n")); | |
1435 | ||
1436 | if (!bfd_set_section_alignment (dynobj, sec, | |
1437 | non_lazy_plt_alignment)) | |
1438 | goto error_alignment; | |
1439 | ||
1440 | htab->plt_got = sec; | |
1441 | ||
1442 | if (lazy_plt) | |
1443 | { | |
1444 | sec = NULL; | |
1445 | ||
1446 | if (use_ibt_plt) | |
1447 | { | |
1448 | /* Create the second PLT for Intel IBT support. IBT | |
1449 | PLT is supported only for non-NaCl target and is | |
1450 | is needed only for lazy binding. */ | |
1451 | sec = bfd_make_section_anyway_with_flags (dynobj, | |
1452 | ".plt.sec", | |
1453 | pltflags); | |
1454 | if (sec == NULL) | |
1455 | info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n")); | |
1456 | ||
1457 | if (!bfd_set_section_alignment (dynobj, sec, | |
1458 | plt_alignment)) | |
1459 | goto error_alignment; | |
1460 | } | |
1461 | else if (info->bndplt && ABI_64_P (dynobj)) | |
1462 | { | |
1463 | /* Create the second PLT for Intel MPX support. MPX | |
1464 | PLT is supported only for non-NaCl target in 64-bit | |
1465 | mode and is needed only for lazy binding. */ | |
1466 | sec = bfd_make_section_anyway_with_flags (dynobj, | |
1467 | ".plt.sec", | |
1468 | pltflags); | |
1469 | if (sec == NULL) | |
1470 | info->callbacks->einfo (_("%F: failed to create BND PLT section\n")); | |
1471 | ||
1472 | if (!bfd_set_section_alignment (dynobj, sec, | |
1473 | non_lazy_plt_alignment)) | |
1474 | goto error_alignment; | |
1475 | } | |
1476 | ||
1477 | htab->plt_second = sec; | |
1478 | } | |
1479 | } | |
1480 | ||
1481 | if (!info->no_ld_generated_unwind_info) | |
1482 | { | |
1483 | flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | |
1484 | | SEC_HAS_CONTENTS | SEC_IN_MEMORY | |
1485 | | SEC_LINKER_CREATED); | |
1486 | ||
1487 | sec = bfd_make_section_anyway_with_flags (dynobj, | |
1488 | ".eh_frame", | |
1489 | flags); | |
1490 | if (sec == NULL) | |
1491 | info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n")); | |
1492 | ||
1493 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) | |
1494 | goto error_alignment; | |
1495 | ||
1496 | htab->plt_eh_frame = sec; | |
1497 | ||
1498 | if (htab->plt_got != NULL) | |
1499 | { | |
1500 | sec = bfd_make_section_anyway_with_flags (dynobj, | |
1501 | ".eh_frame", | |
1502 | flags); | |
1503 | if (sec == NULL) | |
1504 | info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n")); | |
1505 | ||
1506 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) | |
1507 | goto error_alignment; | |
1508 | ||
1509 | htab->plt_got_eh_frame = sec; | |
1510 | } | |
1511 | ||
1512 | if (htab->plt_second != NULL) | |
1513 | { | |
1514 | sec = bfd_make_section_anyway_with_flags (dynobj, | |
1515 | ".eh_frame", | |
1516 | flags); | |
1517 | if (sec == NULL) | |
1518 | info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n")); | |
1519 | ||
1520 | if (!bfd_set_section_alignment (dynobj, sec, class_align)) | |
1521 | goto error_alignment; | |
1522 | ||
1523 | htab->plt_second_eh_frame = sec; | |
1524 | } | |
1525 | } | |
1526 | } | |
1527 | ||
1528 | if (normal_target) | |
1529 | { | |
1530 | /* The .iplt section is used for IFUNC symbols in static | |
1531 | executables. */ | |
1532 | sec = htab->elf.iplt; | |
1533 | if (sec != NULL | |
1534 | && !bfd_set_section_alignment (sec->owner, sec, | |
1535 | plt_alignment)) | |
1536 | goto error_alignment; | |
1537 | } | |
1538 | ||
1539 | return pbfd; | |
1540 | } |